JPH0537455A - Time-division communication method for mobile object communication - Google Patents

Abstract

(57) [Abstract] [Purpose] To provide mobile communication in which a time-compressed telephone or image signal is placed in a frame-structured time slot. [Configuration] Each wireless base station 30 covering a plurality of zones
And a barrier for exchanging communication with each mobile radio 100 using a radio channel carrying a temporally compressed delimited signal in a time slot of a frame structure for communicating with a radio base station. Using the exchange 20, the differential signal is obtained for each frame with respect to the analog image signal, time-compressed, accommodated in a time slot and amplitude-modulated, and the amplitude-modulated signal is time-compressed and time-slotted. Frequency modulation is performed by the telephone signal accommodated in. [Effect] The transmission level of the composite signal can be determined based on the multiple load gain, and the composite signal can be simultaneously communicated by one carrier.

Description

Detailed Description of the Invention

[0001]

The present invention relates to ISDN (Integrated S
ervices Digital Network) The present invention relates to a time-division wireless base station and a mobile wireless device for a wireless communication channel in mobile communication that has entered the era. More specifically, one of a number of radio channels provided to the system is provided, and one of a number of mobile radios in the service area is used by the radio channel of the opposite radio base station. For example, while a wireless line is set up by a signal that combines telephone and telephone or a combination of telephone and image and communication is performed using the communication signal, another mobile wireless device desires to use the same wireless channel for communication. In this case, independent radio communication is performed between the other mobile radio device and the radio base station using the same radio channel without adversely affecting the communication between the mobile radio device and the radio base station which are already in communication. The present invention relates to a time division communication system of the same radio channel which sets up a line and enables communication of composite signals including telephone, fax, data and image signals.

[0002]

2. Description of the Related Art In mobile communication using voice to which a small zone method is applied, a method using a time division time compression multiplexed signal is described in the following document.

Reference 1. Ito "Study on mobile phone systems-Proposal of time division time compression FM modulation system-" IEICE Technical Report RC
S89-11 July 1989

Reference 2. Ito "Study on mobile phone systems-Study on multipath propagation characteristics of time division time compression multiple FM system-"
IEICE Technical Report RCS89-47 January 1990

Reference 3. Ito "Elucidation of multiple load gain of time division time compression multiplex telephone signal and its application to FM mobile communication" IEICE Technical Report RCS89-65 Mar. 1990.

Reference 4. Nakagomi ed. "Image Communication Technology" Telecommunications Association 9-12 pages Published in 1982

That is, in Reference 1, a transmission signal (baseband signal) is divided into predetermined time interval units and stored in a memory circuit, and when reading this, the speed is n times faster than the speed of storing in the memory circuit. Built in mobile radios and radio base stations to read at a predetermined time slot, angle-modulate or amplitude-modulate a carrier wave with the signal accommodated in this time slot, and to transmit and receive intermittently in time. , A switch for a radio receiving circuit having a receiving mixer that communicates with each other, a radio transmitting circuit having a transmitting mixer, a synthesizer applied to the receiving mixer of the radio receiving circuit, and a synthesizer applying to the transmitting mixer of the radio transmitting circuit A circuit is provided, and the output of the synthesizer applied to each is interrupted, and this interrupted state is transmitted and received. For the wireless base station that communicates with each other in an expected manner, the same method as described above for synchronizing the intermittent transmission and reception with that of the mobile wireless device is used, and the receiving side extracts only the signal accommodated in the predetermined time slot. Therefore, by opening and closing the wireless receiving circuit, receiving and demodulating, the signal obtained is stored in the memory circuit, and at the time of reading this, by reading at a low speed of 1 / n of the speed stored in this memory circuit, A system example in which a system that enables reproduction of a transmitted baseband signal, which is an original signal, is constructed has been reported.

Further, in Reference 2, the effect of multipath fading that a TCM signal receives during transmission in space is examined, and guard time is set between time slots as a measure for eliminating or reducing this effect. I suggest you do.

Further, in Document 3, the multiplex load gain, which has been known to exist in the FDM (frequency division multiplex) signal in the past, has a multiplex load gain similar to that of the FDM signal in the time division time compression multiplex (TCM) system. Reveal that, and
It explains the quantification and operation examples of the system. Then, by using this multiple load gain to deepen the modulation depth of the FM, the transmission power can be significantly reduced, and it is expected that the mobile wireless device can achieve a significant power saving. Has been reported.

In Document 4, the characteristics of the image signal are explained, and therefore the main part thereof is cited. Here, an image is an information form spatially reproduced and displayed by some technical means, and finally refers to what is presented to humans as visual information.

An image that does not change with time is called a still image (or still image), and can be considered by omitting the time.
On the other hand, an image in which the target changes with time is called a moving image (or moving image). As a moving image, there is a type in which an object changes continuously with time, and a type in which still images are sequentially presented at short intervals like a television or a movie.

In order to transmit or process an image which is an information form distributed on a two-dimensional plane, it is usually required to
It is necessary to perform scanning in order to convert a dimensional signal (image) into a one-dimensional signal. In general, a method (line scanning) is used in which a gray value or the like is obtained by tracing a two-dimensional plane in order from the top along a straight line running in the horizontal direction at regular intervals. In many cases, a screen taken out at a fixed time interval Δt is scanned for a moving image, and each screen is called a frame.

When designing a system or equipment for image processing and transmission, it is important to understand the statistical properties of image information to be handled. An amplitude distribution, an autocorrelation function, a spatial frequency spectrum, etc. are used as statistics. Of these, the amplitude distribution is related to the multiple load gain of the TCM signal.

The amplitude distribution itself, which represents the distribution of the intensity of light and shade in an image, has a strong dependence on each image and cannot be generally discussed. As a practically useful one, the difference between the current pixel g _i and the pixel immediately before it (pixel on the adjacent scan line within the same scan line or at the same coordinate in the previous frame) g _i−1 There is a distribution of signal amplitudes d _i = g _i −g _i−1 . The distribution of d _i is generally smaller than that of the original image signal. This distribution can be approximately represented by the Laplace distribution (negative exponential distribution) shown in Expression (1).

P (d) = 2 ^−1/2 σ ⁻¹ exp (−2 ^1/2 | d | / σ) (1) where σ is the effective value of the difference signal.

The meaning of this equation (1) is as follows.
When a time difference image signal is created from a still image that does not change with time, there is no signal at all. Next, sit on a chair in the room 1
In an image where only one person is on the screen and making a phone call, it is considered that only the mouth or a part of the face moves slightly and other parts of the body are stationary. .. Since the other parts of the room are completely stationary, the time difference image signal in this case is a very small signal output. The output of the time difference image signal may be slightly larger on the screen when the person is walking in the room than when the user is sitting on the upper chair. The output of the time difference image signal is further increased in the image signal in which a person is walking on the street. The image signal that maximizes the output of the time difference image signal may be, for example, a case where a group image of a race horse is photographed by a telephoto lens from a long distance in a horse race. However, the time rate of such signals is extremely low and is usually considered to be in the middle of the two extremes. The same applies to a digital signal, and there is an example in which the time difference image signal is used in the existing system to reduce the amount of information as compared with the case where the image signal is transmitted as it is.

However, in the ISDN era, the opposing radio base station and mobile radio set up a radio line, and I
In a system in which a plurality of communication signals such as a telephone and a telephone, a telephone and an image, which are one of the signal forms in the SDN era, are simultaneously used, the same carrier wave is subjected to angle modulation and angle modulation by two independent signals, Or, perform complex modulation such as angle modulation and amplitude modulation, and
When performing these modulations, the level of the signal that determines the modulation depth is based on the multiple load gain of the signal, and the description of transmitting and receiving a composite signal using this composite modulated wave is made in any document. Not not.

Further, although the characteristic of the difference signal in the image signal has been clarified in Document 4, there is no description or suggestion about application of the multiple load gain to the image signal.

[0019]

A radio base station and a large number of mobile radio units facing each other establish a radio line, and, for example,
When communicating using a plurality of communication signals (hereinafter referred to as composite signals) such as a TCM-converted telephone and a telephone and an image, an angle or amplitude of a carrier wave generated by the TCM-converted composite signal as in the conventional method. In modulation, when the signal compression ratio is increased, the maximum frequency of the signal included in the TCM-converted signal is increased, and the TC ratio is increased without increasing the signal compression ratio.
When M is used, the time slot length becomes longer, and therefore the frame length becomes longer.
There was a problem to be solved that the expected effect could not be obtained. Further, it has been left as an unsolved problem to clarify means for effectively obtaining multiple load gains in wireless transmission of image signals.

[0020]

When a wireless base station and a large number of mobile wireless devices (n units) facing each other set up wireless lines and communicate by using a composite signal, transmission from the wireless base station is performed. The generated TCM signal is created as follows. That is, a TCM signal in which n telephone signals and n telephone or time difference image signals forming a composite signal are separated is created, and these are used to perform angle modulation or amplitude modulation on the same carrier. .. When performing these modulations, the level of the signal that determines the modulation depth is based on the multiple load gain of the signal. This composite modulated wave is transmitted to many mobile radio devices. On the other hand, in many mobile radio units facing each other,
It is received in a slot and demodulated by a process reverse to that used when the composite signal is modulated. Also, regarding the composite signal transmitted from the mobile radio device to the radio base station, a telephone signal and a telephone signal,
Alternatively, after the telephone signal and the time difference image signal are subjected to the same time compression as that performed in the wireless base station, the same kind of angle modulation or amplitude modulation as performed in the wireless base station is performed on the same carrier. Configured. The system configuration will be described.

[0021] A plurality of radio base stations having radio transceivers, a radio receiving circuit having a reception mixer for communicating while moving within a service area covered by the plurality of radio base stations, and a radio transmission having a transmission mixer. A circuit, switching receiving means including a synthesizer capable of switching and receiving signals of two channels by applying two frequencies to the receiving mixer of the wireless receiving circuit, and 2 for the transmitting mixer of the wireless transmitting circuit.
In a mobile wireless device including a switching transmission unit including a synthesizer capable of switching and transmitting signals of two channels by applying one frequency, transmission signals (composite signals such as telephone and time difference image signals) are predetermined. The data is divided into time intervals and stored in the memory circuit, and when this is read out, it is read out at a predetermined time slot at a speed n times faster than the speed at which it is stored in the memory circuit. It is called a TCM signal.)
The same carrier is angle-modulated or amplitude-modulated by a TCM-converted telephone signal, and further angle-modulated or amplitude-modulated by a TCM-converted time difference image signal, and is transmitted to a mobile radio device and a radio base station to be transmitted and received intermittently in time. A built-in radio receiving circuit having a receiving mixer that communicates with each other, a radio transmitting circuit having a transmitting mixer, a synthesizer applied to the receiving mixer of the radio receiving circuit, and a synthesizer applying to the transmitting mixer of the radio transmitting circuit. A switch circuit is provided to switch the output of the synthesizer applied to each of them, and synchronize this interrupted state for both transmission and reception, and synchronize the intermittent transmission and reception similar to the above with that of the radio base station to the mobile radio that communicates oppositely. Method, the receiving side extracts only the signal accommodated in the predetermined time slot. , The signal received by opening and closing the radio receiving circuit and demodulating by a process completely opposite to that at the time of transmission is stored in the memory circuit, and at the time of reading this, it is 1 / n of the speed stored in this memory circuit. The baseband signal, which is the original signal transmitted, is read at a low speed, and the radio base station is provided with a call path control means for setting a call path with a predetermined mobile radio device using a predetermined time slot. We have constructed a system that includes a gateway switch for connecting a general telephone network and a radio base station, by enabling the reproduction of radio waves in a radio base station and a mobile radio device.

[0022]

In order to allow a large number of mobile radios to exist in the radio base station and its service area and to communicate with the radio base station by any number of mobile radios, one radio channel is temporally arranged. It is divided into a plurality of time slot series, and one of these time slot series is selected and communication is performed using this. When one mobile radio device is communicating with a radio base station using a composite signal and another mobile radio device desires to communicate with this radio base station, the mobile radio device that newly wishes to communicate using the composite signal In the wireless channel already in use, an unused one of the time slot sequences is given to the device to enable communication with the wireless base station, so that many communications can be performed. It is possible to execute communication without interfering with each other and without adversely affecting own communication.

Further, while one radio base station and the mobile radio are communicating using one time slot in one channel (one time slot of the old channel), communication of In order to maintain and improve the quality, one time slot in the same or another channel with another radio base station satisfying a certain communication quality (one time slot of a new channel I tried to communicate using a slot. The gateway switch also determines the radio channel used for communication with the mobile radio at the radio base station and its time slot as an interface function for connection with other telephone networks and a control function for the mobile radio communication network. , It has a function to stop and start radio waves.

As a result, even if all the radio channels given to the system are in use, if there is an empty time slot that is not used for communication in each time-divided time slot of each radio channel, It is also possible to make a call to a mobile wireless device that has newly requested a call, and to continue a call to a mobile wireless device that is moving during a call from an adjacent zone. It has become possible for mobile radios communicating with a station to perform diversity communication with other radio base stations in the vicinity.

The modulation method used there is to use the same carrier wave as a TCM-converted telephone signal for angle modulation, and
Since the composite modulation of angle-modulating or amplitude-modulating by another CM-converted telephone signal or time difference image signal is used, the spread of the sideband of the modulated signal is limited to a certain spread by the band-pass filter, so that the wireless signal The degree of spread of the sideband signal that it has when it is angle-modulated or amplitude-modulated by a substantially single signal (when it is angle-modulated or amplitude-modulated by a signal having a higher frequency of the telephone signal or the time difference image signal). It is possible to suppress the spread of the sideband signal.

Further, when a plurality of the time difference image signals as described above are time-compressed and inserted into respective time slots to produce TCM signals, the multiple load gain of the telephone signal described in the above-mentioned reference 3 is obtained. In the same manner as the occurrence of the above, the plurality of time difference image signals can obtain the multiple load gain determined by the parameter of the original image signal (related to σ in the equation (1)).

In addition, a TCM (time division time compression multiplex) signal is contained in one frame, such as a videophone (an analog type signal, hereinafter, all signal types are analog type unless otherwise specified). It has various kinds of signals such as image signals (hereinafter referred to as composite signal), and
When the frequency band, signal compression rate, etc. of these composite signals are different, each is divided into subframes, and the number of multiplexes (the number of channels) in the subframes, the time length of the subframes, and the multiple load gain of the original signal Was obtained with reference to Reference 3, and the design method of the system using the composite TCM signal was clarified to make the system practicable. Particularly in the case of an image signal, each frame is compared with the immediately preceding frame signal, and the image signal (time difference image signal) obtained by extracting only the temporal change in amplitude is taken as a temporally compressed partitioned signal. As a result, a large multiple load gain can be obtained.

As a result, even in the composite TCM signal,
Since there are different multiple load gains for different signal groups, such as the frequency band and signal compression rate of the original signal, and since it is possible to quantify, multiple load gains can be calculated using various design parameters of the system. It becomes possible to calculate concretely, and while keeping interference and interference etc. within the allowable value, FM
By increasing the modulation degree of (PM) and AM modulation, the transmission output can be gradually reduced. Therefore, the amplifier can be easily designed, and the rated values of passive circuits such as mixers, resistors, and capacitors can be lowered, and an economical system can be constructed.

[0029]

[Example] As a system to which the invention is applied, ISDN (Integrated Servic) is expected to be introduced worldwide in the future.
es Digital Network) is a comprehensive service and digital network. Not only telephones but also non-telephone terminals such as faxes, images and data exist as communication terminals of the ISDN system.

Therefore, in the system to which the present invention is applied, an analog telephone signal is transmitted by TC in order to explain its principle.
The case of using after converting to M will be described.

FIG. 1 shows a system configuration for explaining the concept of the present invention. In FIG. 1, 10 is a general telephone network, and 20 is a gateway switch for switching and connecting the telephone network 10 and a wireless system. Reference numeral 30 denotes a wireless base station, which has an interface with the gateway switch 20, a circuit for converting the speed of signals, a circuit for allocating and selecting time slots, a control unit, etc. for setting and releasing a wireless line. , Mobile radio 100 (100-1 to 100-n)
And a wireless transmission / reception circuit for exchanging wireless signals.
Here, between the gateway switch 20 and the wireless base station 30,
There are transmission lines for transmitting the communication signals 22-1 to 22-n including the communication signals of the communication channels CH1 to CHn and the control signals.

FIG. 2 illustrates the principle of the present invention.
The circuit configuration of the mobile wireless device 100 that communicates with the wireless base station 30 is shown. Received signals such as control signals and call signals received by the antenna unit enter the wireless reception circuit 135 including the reception mixer 136 and the reception unit 137, and the output communication signal is the speed restoration circuit 138 and the control unit 140.
Is input to the clock regenerator 141. The clock regenerator 141 regenerates a clock from the received signal and applies it to the speed restoration circuit 138, the control unit 140, and the timing generator 142.

The speed restoring circuit 138 restores the speed (pitch in the case of an analog signal) of the compressed and delimited communication signal in the received signal, and inputs it to the telephone unit 101 and the control unit 140 as a continuous signal. ing.

The communication signal output from the telephone unit 101 is divided by the speed conversion circuit 131 at predetermined time intervals, and the speed (pitch in the case of an analog signal) is made high (compressed) and transmitted. Mixer 133 and transmitter 134
And is applied to the wireless transmission circuit 132 including. The signal level of the TCM-converted signal (however, in the case of the mobile wireless device 100, the TCM-converted signal of only one channel) to the modulator included in the transmitting unit 134 has a multiple load gain (the radio base station 30). Value at the time of full implementation of the time slot) at the time of transmission).

The output of the modulator included in the transmission unit 134 is converted into a predetermined radio frequency in the transmission mixer 133,
The signal is transmitted from the antenna unit and received by the wireless base station 30. In order to send a radio signal to the radio base station 30 using the time slot permitted to be used by the mobile radio device 100, the timing information from the timing generator 142 shown in FIG. Must have been obtained.

The timing generator 142 supplies the necessary timing to the transmission / reception interrupt controller 123, the speed conversion circuit 131 and the speed restoration circuit 138 by the clock from the clock regenerator 141 and the control signal from the control unit 140. There is.

The mobile radio 100 further includes synthesizers 121-1 and 121-2 and a changeover switch 122.
-1, 122-2 and changeover switches 122-1 and 122
-2 includes a transmission / reception gating controller 123 and a timing generator 142 that generate signals for switching each of -2, and the synthesizers 121-1 and 121-2, the transmission / reception gating controller 123, and the timing generator 142 are control units. It is controlled by 140. Each synthesizer 121
The reference frequency is supplied to the -1, 121-2 from the reference crystal oscillator 120.

FIG. 3 shows a radio base station 30 for explaining the principle of the present invention. The n-channel communication signals 22-1 to 22-n with the gateway switch 20 are connected to a signal processing unit 31 that forms an interface on a transmission path.

The communication signals 22-1 to 22-n sent from the gateway switch 20 are input to the signal processing section 31 of the radio base station 30. The signal processing unit 31 is provided with an amplifier for compensating for transmission loss, and also performs so-called 2-wire-4 wire conversion. That is, the input signal and the output signal are mixed and separated, and the input signal from the gateway switch 20 is sent to the signal speed conversion circuit group 51. The output signal from the signal speed restoration circuit group 38 is transmitted to the gateway switch 20 by the signal processing unit 31 using the same transmission path as the input signal. Of the above, the input signal from the gateway switch 20 is input to the signal speed conversion circuit group 51 including many signal speed conversion circuits 51-1 to 51-n, and the speed (pitch) conversion is performed by dividing the signal speed conversion circuit group 51 at predetermined time intervals. receive. In addition, the signal transmitted from the wireless base station 30 to the gateway switch 20 is the wireless reception circuit 3
The output of No. 5 is input to the signal speed restoration circuit group 38 via the signal selection circuit group 39, speed (pitch) converted, and input to the signal processing unit 31.

The control of the radio receiving circuit 35 or the output of the call signal is performed by the signal selection circuit group 3 including the signal selection circuits 39-1 to 39-n for selecting the signal for each time slot.
9, and the call signals are separated corresponding to each of the call channels CH1 to CHn. This output is input to the signal processing unit 31 after being restored in the signal speed (pitch) by the signal speed restoring circuit group 38 including the signal speed restoring circuits 38-1 to 38-n provided for each channel. 4-line-2
After undergoing line conversion, this output is sent to the gateway switch 20 as communication signals 22-1 to 22-n.

Next, the function of the signal speed conversion circuit group 51 will be described. The input signal such as a voice signal or a control signal, which is divided into a certain time length, is stored in a storage circuit, and the speed is changed when reading the input signal, and the read signal is read at a speed of, for example, 15 times that of the storage time. Can be compressed. The principle of the signal speed conversion circuit group 51 is tape
This is the same as playing back the sound recorded by the recorder at high speed. In practice, for example, CCD (Charge Coupl
ed Device) and BBD (Bucket Brigade Device) can be used, and the memory used in a television receiver or a tape recorder for compressing or expanding the time axis of conversation can be used (reference: Kosaka et al. "Tape recorder that compresses / expands the time axis of conversation" Nikkei Electronics July 26, 1976 92-1
33).

CCD exemplified by the signal speed conversion circuit group 51
The circuit using the BBD or BBD can be used as it is for the signal speed restoration circuit group 38 as described in the above document. In this case, the clock from the clock generator 41 and the control signal from the control unit 40 are used. By receiving the timing signal from the timing generator 42 that generates the timing, the read speed is set lower than the write speed.

The control or voice signal output from the gateway switch 20 via the signal processing unit 31 is input to the signal speed conversion circuit group 51, and the speed (pitch) conversion processing is performed, and then the time slot is set. It is applied to a signal allocation circuit 52 which separately allocates signals.

The signal allocating circuit 52 is a buffer memory circuit, which outputs 1 signal output from the signal speed converting circuit group 51.
A high-speed signal corresponding to a delimiter is stored in memory, the signal in the buffer memory is read out by the timing information from the timing generation circuit 42 given by the instruction of the control unit 40, and the signal is sent to the wireless transmission circuit 32. As a result, when the communication signals are viewed as channels, they are arranged in series without overlap in time series, and when all the communication signals or control signals described later are implemented, it is as if they were continuous signal waves. become.

The above signals are sent to the wireless transmission circuit 32. The state of this compressed signal will be described with reference to FIG.

The output signals of the signal speed conversion circuit group 51 are input to the signal allocation circuit 52 and given time slots in a predetermined order. S in FIG. 4 (a)
Dn, SD2, ..., SDn indicate that the speed-converted communication signals are assigned to each time slot. Here, in one time slot, a synchronizing signal and a call signal or / and a control signal are accommodated as shown in the figure. When the call signal is not installed, an empty slot signal is added to the call signal portion only with the synchronization signal, or in some systems, no signal including the carrier wave is transmitted. In this way, as shown in FIG. 4A, in the wireless transmission circuit 32, a signal forming one frame in the time slots SD1 to SDn is added to the modulation circuit. However, the signal level of the TCM-converted signal applied to the wireless transmission circuit 32 is determined based on the multiple load gain of the signal (usually the value at the time of all mounting at the time of transmission of the wireless base station 30).
The multiplex signals that are time-series to be transmitted are angle-modulated in the wireless transmission circuit 32, and then transmitted to the space from the antenna section.

Regarding the transmission of the control signal between the radio base station 30 and the mobile radio 100 prior to the telephone call when making or receiving a telephone call, either in the band of the telephone signal or out of the band is used. It is possible. FIG. 5 shows these frequency relationships. That is, in the figure (a), the out-of-band signal is illustrated, and the low frequency side (250 Hz) or the high frequency side (3850 Hz) can be used. This signal is used, for example, when sending a control signal during a call. FIG. 5B shows an example of the in-band signal, which is used when making and receiving a call. In the above examples, tone signals are used. However, by increasing the number of tone signals or modulating the tones to form subcarrier signals, it is possible to transmit various types of signals at high speed.

Although the above is the case of the analog signal, when the digital data signal is used as the control signal, it is also possible to digitally encode the voice signal and time-division multiplex both of them for transmission. A circuit configuration in this case is shown in FIG. FIG. 6 shows an example in which the voice signal is digitized by the digital encoding circuit 91, the data signal and the data signal are multiplex-converted by the multiplex conversion circuit 92, and applied to the modulation circuit included in the wireless transmission circuit 32. However, for digital data signals, the analog signal multiple load gain, which will be described later, does not normally exist, so this point must be noted in the system design. Then, if the opposite receiver receives the signal and the demodulation circuit performs the reverse operation to that shown in FIG. 6, the audio signal and the control signal can be separately taken out.

On the other hand, the signal transmitted from the mobile radio 100 is received by the antenna section of the radio base station 30 and input to the radio receiving circuit 35. FIG. 4B schematically shows this upstream input signal. That is, the time slots SU1, SU2, ..., SUn represent transmission signals addressed to the radio base station 30 from the mobile radios 100-1, 100-2, ..., 100-n. Further, when the contents of each time slot SU1, SU2, ..., SUn are shown in detail,
As shown in the lower left of FIG. 4B, it is composed of a call signal and / or a control signal. However, the synchronization signal can be omitted depending on the case where the distance between the mobile wireless device 100 and the wireless base station 30 is small or the signal speed. Further, when the waveform of the radio carrier of the uplink radio signal of FIG. 4B in a time slot is schematically shown, FIG.
It becomes like (c). Similarly, the downlink transmission waveform from the wireless base station 30 to each mobile wireless device 100 in FIG. 4A is as shown in FIG. 7D.

FIG. 8 shows that the telephone and image signals are sent at the same time.
The frame and time slot configuration for transmission in slots is shown. In this case, since the signal frequency bandwidth and the maximum signal frequency of the telephone or image signal are different from each other, if the signals are compressed at the same compression rate, naturally the maximum signal frequency of the compressed signal will be different. However,
It is assumed that the time lengths of the time slots of the telephone or the image signal are the same and that they are transmitted in the same time slot. In this case, since the telephone or image signal is modulated separately from each other, as will be described later, one is frequency-modulated and the other is amplitude-modulated, so that both signals are not mixed. In addition, the same carrier wave is used for the effective use of the frequency and is output from the wireless transmission circuit 32.

The control signal of the input signals arriving at the radio base station 30 is immediately added from the radio reception circuit 35 to the control unit 40. However, depending on the size of the speed conversion rate, it is possible to add the signal from the output of the signal speed restoration circuit group 38 to the control unit 40 after performing the same processing as the call signal. The call signal is applied to the signal selection circuit 39. The signal selection circuit group 39 includes a control unit 4
In response to an instruction from the control signal from 0, a timing signal from a timing generation circuit 42 that generates a predetermined timing is applied, and a synchronization signal, a call signal or a control signal is separately output for each time slot SU1 to SUn.

Each of these signals is sent to the signal speed restoration circuit 38.
Is input to. This circuit has a function of performing inverse conversion of the speed conversion circuit 131 (FIG. 2) in the mobile radio device 100 on the transmission side, whereby the original signal is faithfully reproduced and transmitted to the gateway exchange 20. Become.

Hereinafter, an aspect of transmitting the signal space according to the present invention will be described with reference to the required transmission band and the relationship with the adjacent radio channel.

As shown in FIG. 3, the control signal from the control unit 40 is applied to the radio transmission circuit 32 in parallel with the output of the signal allocation circuit 52. However, depending on the size of the speed conversion rate, after the same processing as the call signal is performed, the signal allocation circuit 5
It is also possible to add from the output of 2 to the wireless transmission circuit 32. Next, also in the mobile wireless device 100, as shown in FIG. 2, of the functions of the wireless base station 30, the circuit configuration is required when the communication channel is one channel.

Original signal, eg voice signal (0.3 kHz-
FIG. 9 shows the frequency distribution on the output side when 3.0 kHz) passes through the signal speed conversion circuit group 51 (FIG. 3). That is, if the audio signal is converted 15 times as described above, the frequency distribution of the signal is as shown in FIG.
It means that the frequency is expanded to 4.5 kHz to 45 kHz. Although the frequency distribution of the signal is expanded here, it should be noted that the shape of the waveform simply undergoes a similarity transformation in which the frequency axis is stretched, and the waveform itself does not change.

Now, FIG. 9 shows a case where the control signal is simultaneously transmitted using the lower frequency band of the audio signal. Of these signals, control signals (0.2 to 4.0)
kHz) and the speech signal CH1 (represented as SD1 at 4.5-45 kHz) are contained in a time slot, for example SD1. The same applies to audio signals accommodated in the other time slots SD2 to SDn.

That is, the time slot SDi (i =
2, 3, ..., N) is a control signal (0.2 to 4.0 kH)
z) and the communication signal CHi (4.5 to 45 kHz). However, the signals in each time slot are arranged in time series, and the signals in a plurality of time slots are not simultaneously applied to the wireless transmission circuit 32.

When these call signals are added to the angle modulator included in the radio transmission circuit 32 together with the control signal, a required transmission band of at least f _C ± 45 kHz is required. However, f _C is a radio carrier frequency. If there are a plurality of wireless channels given to the system, the speedup of signals by the signal speed conversion circuit group 51 is limited to a certain value due to the limitation of these frequency intervals. F is the frequency interval of a plurality of wireless channels
Let _rep be the maximum signal speed f _H due to the speedup of the audio signal described above, and the following inequality must be established between the two. f _rep > 2f _H On the other hand, in the case of a digital signal, the voice is usually digitized at a speed of about 64 kb / s. Therefore, it is necessary to read the scale of the horizontal axis in FIG. However, the relation of the above equation holds in this case as well.

Further, from the mobile radio 100 to the radio base station 3
The control signal input to 0 is input to the wireless reception circuit 35, part of its output is input to the control unit 40, and the other is sent to the signal speed restoration circuit group 38 via the signal selection circuit 39. .. The latter control signal undergoes speed conversion (conversion to a low speed signal) completely opposite to that at the time of transmission, and then the general telephone network 10
The signal speed is the same as that used in the above, and it is sent to the gateway exchange 20 via the signal processing unit 31.

Next, various operations of the system according to the present invention will be described in the following order, and the present invention will be theoretically proved to be highly practical. (1) Call origination and termination operations (2) Theoretical explanation of the present invention (a) Mathematical expression of modulated wave (b) Sideband spread of modulated wave (c) Calculation of frequency effective utilization rate (3) Composite signal System configuration

(1) Calling and Receiving Operations Calling operations will be described with reference to the flow charts shown in FIGS.

When the power of the mobile wireless device 100 is turned on, in the wireless receiving circuit 135 of FIG. 2, the wireless receiving circuit 135 is included in the downlink (wireless base station 30 → mobile wireless device 100) wireless channel (referred to as channel CH1). Start capturing control signals. If the system is provided with multiple radio channels, i) the radio channel showing the maximum received input field ii) the radio channel indicated by the control signals contained in the radio channel iii) Within the radio channel , The wireless channel (hereinafter referred to as channel CH1) is being received according to the procedure defined in the system, such as the channel having an empty time slot. This is possible by capturing the sync signal in the time slot SDn shown in FIG. 4 (a). In the control unit 140, the synthesizer 121-1
To the switch 1 so as to generate a local oscillation frequency that enables reception of the radio channel CH1.
22-1 is also in a state of being tilted down and fixed to the synthesizer 121-1 side.

Therefore, the telephone of the telephone unit 101 is turned off.
When a hook (call origination) is made (S201, FIG. 10), FIG.
The synthesizer 121-2 of receives the control signal from the control unit 140 so as to generate the local oscillation frequency that enables the transmission of the radio channel CH1. Further, the switch 122-2 is also tilted to the synthesizer 121-2 side to be in a fixed state. Next, the call control signal output from the telephone unit 101 is transmitted using the radio channel CH1. This control signal is transmitted by the frequency band shown in FIG. 9 using, for example, the time slot SUn.

This control signal is transmitted in the time slot S
It is limited to only Un and is sent in bursts and no signal is sent in other time zones, so that it does not adversely affect other communications. However, if the speed of the control signal is relatively low, or if the amount of information in the signal is large and cannot be accommodated in one time slot, the same time of one frame later or the next frame Sent using slots.

To capture the time slot SUn:
Specifically, the following method is used. As shown in FIG. 4A, the control signal transmitted from the wireless base station 30 includes a synchronization signal and a control signal that follows it. The mobile wireless device 100 receives the synchronization signal and the frame synchronization. It will be possible. In addition, this control signal contains the currently used time slots and the unused time slots (empty time slots).
Control information such as slot display) is included. Depending on the system, time slot SDi (i = 1, 2,
..., n) is being used by another communication,
Sometimes it only contains sync and call signals,
Even in such a case, the unused time slot normally contains a synchronization signal and a control signal, and by receiving this control signal, the mobile radio 100 uses which time slot to issue a call signal. Can be sent.

When all the time slots are in use, it is impossible to make a call on this radio channel and it is necessary to sweep and search another radio channel.
In another system, there is a case where an empty slot is not displayed in any time slot, and at this time, the following audio multiplexed signals SD1, SD2, ..., SD
It is necessary to search for the presence of n one after another to check for empty time slots.

Returning to the present discussion, the mobile radio 100, which has received the control information sent from the radio base station 30 by any one of the above methods, sends out the call control signal in which time slot. Whether or not it should be possible can be determined by including the transmission timing.

Then, the time slot SU for the upstream signal
Assuming that n is an empty slot, this empty time slot is used, a call-out control signal is transmitted, a required timing is extracted from a response signal from the radio base station 30, and a burst-like control signal is generated. Can be sent out.

If another mobile radio device makes a call at the same time, the call signal is not properly transmitted to the radio base station 30 due to a collision of calls, and it is necessary to restart the operation from the beginning. However, this probability is suppressed to a sufficiently small value when viewed as a system. If it is desired to reduce call collisions further, the following measures are taken. If mobile radio 100 finds an empty time slot that it can make a call, it does not use all of that time slot, but only the first half for some mobile radios and only the second half for some mobile radios. This is the method to use. That is, as a calling signal, the used portion of the time slot is divided into several types, and using this, a large number of mobile radio devices are grouped, and each group is assigned a time zone within that one time slot. How to give. Another method is to create various types of frequencies that the control signal has, and to assign this frequency to each group by grouping a large number of mobile radio devices. According to this method, even if control signals having different frequencies are simultaneously transmitted using the same time slot, interference does not occur in the radio base station 30. The above two methods may be used separately, or if they are used together, the effect is synergistically increased.

Now, the call control signal from the mobile wireless device 100 is properly received by the wireless base station 30, and the mobile wireless device 100 receives the call control signal.
If the ID (identification number) is detected (S202),
The control unit 40 searches for a currently empty time slot. The time slot given to the mobile radio 100 may be SUn, but a search is performed just in case. This is because, in addition to the mobile wireless device 100, it is possible to handle simultaneous calls from other mobile wireless devices and to provide time slots suitable for the service type and service classification.

As a result, for example, time slot SD
1 is available, the time slot SDn of the radio channel CH1 is used for the mobile radio device 100 and the time slot ascending (the mobile radio device 10) by the downlink control signal.
0 → Radio base station 30) SU1, and the corresponding downlink (radio base station 30 → mobile radio 100) SD1 is instructed to be used (S203). In response to this, the mobile wireless device 100 shifts to a state in which it can be received at the instructed time slot SD1 and SU1 which is a time slot for the uplink radio channel corresponding to the downlink time slot SD1 (see FIG. Select b)). At this time, in the control unit 140 of the mobile wireless device 100, the transmission / reception gating controller 123 is operated to turn on the switch 122-1.
And 122-2 are started to operate (S204). At the same time, a slot switching completion report is sent to the radio base station 30 using the uplink time slot SU1 (S205),
Wait for dial tone (S20)
6).

The time of the wireless carrier of this upstream wireless signal
The state of the slot SU1 is shown in FIG. 7 (c). In addition to the time slot SU1, the radio base station 30 receives SU as an uplink signal from another mobile radio 100.
3 and SUn are sent in one frame. In the wireless base station 30 that has received the slot switching completion report (S207), the mobile wireless device 100 is addressed to the gateway switch 20.
The calling signal is sent out together with the ID of (S208). On the other hand, the gateway exchange 20 detects the ID of the mobile wireless device 100, turns on a necessary switch in the switch group included in the gateway exchange 20 (S209), and dials
The tone is transmitted to the radio base station 30 (S210, FIG. 1).
1). This dial tone is transferred to the mobile wireless device 100 by the wireless base station 30 (S211), and the mobile wireless device 100 confirms that the communication path has been set (S2).
212).

When this state is entered, the mobile wireless device 100
Since a dial tone is heard from the handset of the telephone section 101, the transmission of the dial signal is started. This dial signal is subjected to speed conversion by the speed conversion circuit 131, and the wireless transmission circuit 13 including the transmission unit 134 and the transmission mixer 133.
From 2, the data is transmitted using the upstream time slot SU1 (S213). Thus, the transmitted dial signal is received by the wireless reception circuit 35 of the wireless base station 30.

The radio base station 30 has already responded to the calling signal from the mobile radio 100, and has set the time
The slot is given, and the signal selection circuit group 39 and the signal allocation circuit group 52 of the radio base station 30 are operated to receive the uplink time slot SU1 and to transmit the downlink time slot SU1.
The state has shifted to transmitting the signal of the slot SD1.
Therefore, the dial signal transmitted from the mobile wireless device 100 is the signal selection circuit 39-1 of the signal selection circuit group 39.
After passing through, it is input to the signal speed restoration circuit group 38, where the original transmission signal is restored and transferred to the gateway switch 20 as the call signal 22-1 via the signal processing unit 31 (S21).
4) The call path to the telephone network 10 is set (S21).
5).

On the other hand, an input signal (initially a control signal, a call signal if a call is started) from the gateway switch 20 is subjected to speed conversion by the signal speed conversion circuit group 51 in the radio base station 30, and then the signal allocation circuit. Signal allocation circuit 52-1 of group 52
Is given a time slot SD1. Then, the time of the downlink radio channel from the radio transmission circuit 32
It is transmitted to the mobile wireless device 100 using the slot SD1. The state of the time slot SD1 of the downlink radio carrier is shown in FIG. 7 (d).

In the mobile radio 100, the radio channel CH
In the time slot SD1 of No. 1, the reception is awaited, and it is received by the radio reception circuit 135, and its output is input to the speed restoration circuit 138. In this circuit, the original signal on the transmission side is restored and input to the handset of the telephone T included in the terminal unit 102. Thus, a call is started between the mobile wireless device 100 and the ordinary telephone in the ordinary telephone network 10 (S216).

The end of the call is the terminal unit 102 of the mobile radio 100.
By on-hooking the handset of the telephone set T included in (S217), the end signal and the on-hook signal from the control unit 140 are transmitted from the wireless transmission circuit 132 via the speed conversion circuit 131 to the wireless base station. 30 (S218), and the control unit 140 causes the transmission / reception interrupt controller 1
The operation of 23 is stopped, and the switches 122-1 and 122-2 are fixed to the output ends of the synthesizers 121-1 and 121-2, respectively.

On the other hand, in the control unit 40 of the radio base station 30,
When the call end signal from the mobile wireless device 100 is received, the call end signal is transferred to the gateway switch 20 (S219), the switches of the switch group (not shown) are turned off to end the call (S).
220). At the same time, the signal selection circuit group 3 in the radio base station 30
9 and the signal allocation circuit group 52 are opened.

In the above description, the control signals are exchanged between the radio base station 30 and the mobile radio 100 without passing through the signal conversion circuit group 51, the signal speed restoration circuit group 38, etc., but this is explained. For the sake of convenience, the signal speed conversion circuit group 51 and the signal speed restoration circuit group 38 are the same as those for the audio signal.
Communication can be performed without any trouble through the signal processing unit 31 and the signal processing unit 31.

Next, the operation of receiving a call to the mobile wireless device 100 will be described. The mobile wireless device 100 is in a standby state with the power turned on. In this case, as described in the calling operation from the mobile radio 100, the downlink control signal of the radio channel CH1 according to the procedure defined by the system is in the standby state.

An incoming call signal from the general telephone network 10 to the mobile radio 100 via the gateway switch 20 is transmitted to the radio base station 30.
Suppose you have arrived. Similar to the voice signal, these control signals pass through the signal speed conversion circuit group 51, and are transmitted to the control unit 40 (FIG. 3) through the signal allocation circuit group 52, similarly to the voice signal. Then, the control unit 40 uses the empty slot of the downlink time slot of the radio channel CH1 addressed to the mobile wireless device 100, for example, SD1, to move the mobile wireless device 10
0 ID signal + incoming call signal display signal + time slot use signal (for example, for transmission from the mobile radio 100, S
Use SU1 corresponding to D1). In the mobile wireless device 100 that receives this signal, the signal is transmitted from the receiving unit 137 of the wireless receiving circuit 135 to the control unit 140. Control unit 1
At 40, since it is confirmed that this signal is an incoming call signal to the mobile radio device 100 of its own, the telephone unit 101 sounds a ringing tone, and at the same time, it waits at the instructed time slot SD1, SU1. Transmission / reception intermittent controller 1
23, and switches 122-1 and 12
Turn on and off 2-2. Thus, the call is ready to be made.

(2) Theoretical explanation of the present invention

(A) Mathematical Expression of Modulated Wave First, the case where the composite modulation by the angle modulation or the amplitude modulation is not performed but the single angle modulation is explained, and then the effect of the composite modulation according to the present invention is theoretically explained. explain. In the following description, it is assumed that the multiple load gain is not considered with respect to the modulation depth, and in the case where it is considered, it will be described in the section of (3) System configuration in the case of composite signal.

The data or telephone signal (for analog or digital format signal) which is the output signal (or control signal) of the telephone section 101 of FIG. 2 can be expressed as follows.

Μ (t) = Σa _i cos (ω _i t + θ _i ) (2) Here, Σ means that i = 1 to m are summed. Further, the control signal existing outside the band is μ _c (t) = Σa _i cos (ω _i t + θ _i ) (3) where Σ means the sum of i = m + 1 to n, and a _i Is the magnitude of the amplitude, ω _i is the angular frequency of the signal θ _i is t
Represents the phase when = 0. m and n represent positive integers.

Next, the case of frequency modulation will be described.
The invention applies equally to phase modulation and amplitude modulation. When the carrier wave is modulated by the formula (2) or the formula (2) and the formula (3), the obtained modulated wave is I = I ₀ sin ∫ (ω + μ (t)) dt = I ₀ sin (ωt + s (t)) ( 4) Or, I = I ₀ sin ∫ (ω + μ (t) + μ _c (t)) dt = I ₀ sin (ωt + s (t) + s _c (t)) (5)

However, s (t) = Σm _i sin (ω _i t + θ _i ) where Σ represents the sum of i = 1 to m, and s _c (t) = Σm _i sin (ω _i t + θ _i ) Where Σ represents the sum from i = m + 1 to n, and m _i
= A _i / ω _i (i = 1,2,3, ..., n), and s (t) + s _c (t) shown in equation (5) represents a transmission signal of a general form. Become.

By using the equation (4) or the equation (5), the radio signal transmitted from the antenna of the mobile radio 100 is expressed by the following equation. I = (I ₀₁ / n) {1 + 2Σφ ⁻¹ sin φ cosmppt} sin θ ₁ (6) where φ = mπ / n, θ ₁ = Ω ₁ t + s ₁ (t) + s _c1 (t), and n Is the number of slots (equal time intervals) in one frame, Ω ₁ is the carrier angular frequency, p is the switching angular frequency, m
Is a positive odd number, and Σ represents the sum from m = 1 to ∞.

Equation (6) is the case where the transmission signal from the mobile radio 100 using the same radio channel is one of the n slots in one frame, but all slots are implemented by signals. State, that is, n mobile radios 1
When 00 is in communication using the same wireless channel, the display of the signal included in the wireless channel by the mathematical expression is as follows.

I = I ₁ + I ₂ + I ₃ + ... + I _n (7) and I ₁ = (I ₀₁ / n) {1 + 2Σφ ^-1 sin φ cosmpt} sin θ ₁ I ₂ = (I ₀₂ / n) {1 + 2Σφ ⁻¹ sin φ cosmpt ₂ } sin θ ₂ I ₃ = (I ₀₃ / n) {1 + 2Σφ ⁻¹ sin φ cosmpt ₃ } sin θ ₃ …… I _n = (I _0n / n) {1 + 2Σφ ^-1 sin φ cosmpt _n } sin θ _n where Σ represents the sum from m = 1 to ∞.

Further, t ₂ = t−2π / (np) t ₃ = t−4π / (np) ... t _n = t−2 (n−1) π / (np), and θ ₁ = Ω ₁ t + s ₁ (t) + s _c1 (t) θ ₂ = Ω ₂ t + s ₂ (t) + s _c2 (t) θ ₃ = Ω ₃ t + s ₃ (t) + s _c3 (t) …… θ _n = Ω _n t + s _n (t) + s _cn (t), p is the switching angular frequency, m is a positive odd number, and the switching times for the n input waves are at equal intervals.

In the following, the equation (7) is modified because it is necessary for examining the influence of adjacent channel interference, which will be described later. The right side of Expression (7) is expanded as the following expression.

I = (I ₀₁ / n) C ₁ + (I ₀₂ / n) C ₂ + ... + (I _0n / n) C _n (8) where C ₁ = sin θ ₁₀ + b ₁₁ sinφ ₁ + b ₁₃ sinφ ₃ + b ₁₅ sinφ ₅ + …… C ₂ = sinθ ₂₀ + b ₂₁ sinφ ₁ + b ₂₃ sinφ ₃ + b ₂₅ sinφ ₅ + ………… C _n = sinθ _n0 + b _n1 sinφ ₁ + b _n3 sinφ ₃ + b _n5 sinφ ₅ + ...... is.

B ₁₁ = φ ₁ ^-1 (sin θ _11p + sin θ _11n ) b ₁₃ = φ ₃ ^-1 (sin θ _13p + sin θ _13n ) b ₁₅ = φ ₅ ^-1 (sin θ _15p + sin θ _15n ) ... b ₂₁ = φ ₁ ^-1 (sin θ _21p + sin θ _21n ) b ₂₃ = φ ₃ ^-1 (sin θ _23p + sin θ _23n ) b ₂₅ = φ ₅ ^-1 (sin θ _25p + sin θ _25n ) _{………………} b _n1 = φ ₁ ^-1 (sin θ _n1p + sin θ _n1n ) b _n3 = φ ₃ ^-1 (sin θ _n3p + sin θ _n3n ) b _n5 = φ ₅ ^-1 (sin θ _n5p + sin θ _n5n ) ...

Further, φ ₁ = π / n, φ ₃ = 3π / n, φ ₅ = 5π / n, ...

Further, θ ₁₀ = Ω ₁ t + s ₁ (t) + s _c1 (t) θ ₂₀ = Ω ₂ t + s ₂ (t) + s _c2 (t) ... θ _n0 = Ω _n t + s _n (t) + s _cn ( t).

Further, θ _11p = (Ω ₁ + p) t + s ₁ (t) + s _c1 (t) θ _11n = (Ω ₁ −p) t + s ₁ (t) + s _c1 (t) θ _13p = (Ω ₁ + 3p) t + s ₁ (t) + s _c1 (t) − (6π / n) (n−1) θ _13n = (Ω ₁ −3p) t + s ₁ (t) + s _c1 (t) + (6π / n) (n−1) ) Θ _15p = (Ω ₁ + 5p) t + s ₁ (t) + s _c1 (t)-(10π / n) (n-1) θ _15n = (Ω ₁ -5p) t + s ₁ (t) + s _c1 (t) + (10π / n) (n-1) ... θ _21p = (Ω ₂ + p) t + s ₂ (t) + s _c2 (t) θ _21n = (Ω ₂ −p) t + s ₂ (t) + s _c2 (t) θ _23p = (Ω ₂ + 3p) t + s ₂ (t) + s _c2 (t)-(6π / n) (n-1) θ _23n = (Ω ₂ -3p) t + s ₂ (t) + s _c2 (t) + (6π / N) (n-1) θ _25p = (Ω ₂ + 5p) t + s ₂ (t) + s _c2 (t)-(10π / n) (n-1) θ _25n = (Ω ₂ -5p) t + s ₂ (t _{) + s c2 (t) +} (10π n) (n-1) ...... θ n1p = (Ω n + p) t + s n (t) + s cn (t) - (2π / n) (n-1) θ n1n = (Ω n -p) t + s n ( _{t) + s cn (t)} + (2π / n) (n-1) θ n3p = (Ω n + 3p) t + s n (t) + s cn (t) - (6π / n) (n-1) θ n3n = _{(Ω n -3p) t + s} n (t) + s cn (t) + (6π / n) (n-1) θ n5p = (Ω n + 5p) t + s n (t) + s cn (t) - (10π / n _{) (n-1) θ n5n} = (Ω n -5p) t + s n (t) + s cn (t) + (10π / n) (n-1) is ....

From the equation (8), it can be seen that many carriers are combined. The above is n in FIG.
Although it was a radio signal transmitted from each mobile radio device 100, the signal transmitted from the radio base station 30 to each mobile radio device 100 will also be obtained in the same manner. It can be seen that the angular frequency can be set as Ω ₁ = Ω ₂ …… = Ω _n (9).

The mobile radio 100 communicating with the radio base station 30 in communication with each other uses the timing generator 142 and the transmission / reception interrupt controller 123 shown in FIG. It will be used for selective reception. Now, assuming that this is the time slot SD1 shown in FIG. 4 for the mobile wireless device 100-1, the signal becomes the signal shown in the first term on the right side of Expression (7), that is, I ₁ . When the expression (6) passes through the amplitude controller included in the receiving unit 137 of FIG. 2, it has the form as shown in the following expression. I = A sin (Ω ₁ t + s ₁ (t) + s _c1 (t)) (10) However, A is amplitude and is not related to frequency or time. Expression (1
0) passes through the frequency discriminator included in the receiving unit 137, the demodulation output is e (t) = μ (t) + μ _c (t). Then, this output is used as the speed restoration circuit 131 of FIG.
If it passes through, the original signal is reproduced.

[0100] The spread of the sidebands of the radio modulated wave, which is a problem in constructing the system, will be quantitatively evaluated below to explain that the system according to the present invention can be practically operated without any trouble.

(B) Spreading of Sideband of Radio Modulation Wave The expression (8) has a fairly complicated mathematical expression, but the following can be understood by observing the contents of the expression.

(I) When the original carrier wave is modulated with the TCM signal, the switching angular frequency p of each time piece signal constituting the TCM signal causes a large number of sub-carriers (± p, ± around the carrier wave angular frequency Ω). 3p, ± 5p, ...) are present. However,
This effect is remarkable when transmitting using only one time slot, such as when transmitting from the mobile wireless device 100 to the wireless base station 30.
, The effect gradually diminishes as the number of time slots used increases, and does not appear at all when transmitting using all time slots.

(Ii) The original carrier wave and a large number of subcarriers (± p, ± 3p, ± 5p, centering on the carrier angular frequency Ω,
There are a number of sideband signals that occur when each of these is frequency-modulated by TCM.

Therefore, the band width of the signal included in the radio signal represented by the equation (8) becomes very large because the sideband spreads widely. If it is sent to the space as it is, there is a possibility of causing radio wave interference to adjacent channels. Therefore, one countermeasure is to insert a bandpass filter on the input side of the modulated wave so as to limit the spread of the sideband to a certain spread and then add it to the modulator. As another countermeasure, a method of limiting the spread of the sideband to a certain spread by inserting a bandpass filter on the output side of the modulated wave is also in practical use. These are used not only in the case of TCM signals but also in wireless systems in general, and the modulated signal is then converted to a defined carrier frequency (not shown) or the output is increased (not shown), This signal is sent to the space toward the mobile radio 100 that communicates with the other side. However, if the characteristics of the bandpass filter are so strict that the spread of the sideband is limited, distortion noise occurs. So there is a trade-off between the two,
In a microwave analog wireless relay system using a practically used FDM (a signal obtained by frequency division and multiplexing a telephone signal), a band pass filter having the following bandwidth is used. That is, assuming that the maximum frequency of the FDM telephone signal (baseband signal) is F _h , the pass band width of the band pass filter is ± (1.3 to 1.5) F centering on the carrier angular frequency Ω.
It is about _h .

On the other hand, in the case of a TCM-converted telephone signal, there is little distortion noise, and the pass band width of the band pass filter that reduces the possibility of causing radio wave interference to adjacent channels is known. However, a) In the case of a TCM-converted telephone signal, the baseband signal has a large band, as in the FDM signal. b) In addition to a), only one channel of the telephone signal has a wide band, and therefore, even if the band is narrowed, distortion noise is less likely to occur. As a result, the practical limited bandwidth of a radio signal that does not generate a large distortion noise is ± (1.1 around the carrier angular frequency Ω, where ω _L and ω _H are the minimum and maximum frequencies of the TCM-converted telephone signal, respectively. ~ 1.5) ω _H (Here, it is assumed to be 1.5 ω _H for convenience of calculation, but a practical value of 1.2 to 1.33 is assumed to be appropriate). Therefore, considering the existence of the switching angular frequency p of each time piece signal which constitutes the TCM signal, the pass band width of the band pass filter is expressed as 1.5 (ω _m + p) × 2 (11) as a whole. It

FIG. 12 (a) shows the spectrum of the radio signal represented by equation (6). This signal is further amplitude-modulated by a telephone signal (lowest frequency ω _L , highest frequency ω _H ) having the same TCM-converted spectrum as shown in FIG. 12B, with the depth of modulation being k (0 <k ≦ 1). The spread of the sideband in the case of doing will be described. Note that FIG. 12 is schematically shown, in which the energy of the signal wave is represented by electric power, the sideband characteristics of the modulated wave are flat, and the energy is constant over an angular frequency range of 0 to ω _H. There is. FIG. 12A shows only the first sidebands a and b of the frequency modulation wave.

In this case, the equation (6) is expressed as follows. I = (I ₀₁ / n) H (t) {1 + 2Σφ _m ^-1 sinφ _m cos mpt} sin θ ₁ (12) where H (t) = 1 + k (μ (t) + μ _c (t)) φ _m = mπ / n, where μ (t) is the telephone signal and μ _c (t) is its control signal. is there.

Although the expression (12) has a very complicated expression, it is easy to understand if it is considered as follows. That is, the formula (12) has the following formula a ₁ = (I ₀₁ / n) [sin {(Ω ₁ + p) t + s ₁ (t)) on each of the right sides of the formula (8) obtained by expanding the formula (6). Since + s _c1 (t)} is amplitude-modulated, the spread of the sidebands included in the composite-modulated radio signal appears to be larger in addition to the spread of equation (8). However, actually, the spread of the sideband does not become large, and is almost the same as the spread of the sideband included in the single-modulated radio signal.

This will be theoretically explained below. First, it is assumed that the right side of Expression (12) is expanded with some approximation, and is expressed as the following expression. I = (1 + a + b) (c + d) sin Ω ₁ t (13) where, a is the upper sideband of the amplitude modulated wave, b is the lower sideband of the amplitude modulated wave, c is the upper sideband of the frequency modulated wave, and d is the frequency. among under sideband sin Omega ₁ t of the modulated wave: radio carrier now and then expanding the right-hand side of equation (13), I = (c + d) sin Ω 1 t + (a + b) (c + d) sin Ω 1 t (14) equation ( The first term on the right side of 14) expresses the frequency-modulated wave itself, and it can be seen from this term alone that the spread of the sideband does not occur. Next, when the second term on the right side of the equation (14) is further expanded, r = ac + ad + bc + bd (15) However, the term of the wireless carrier wave is omitted in the equation (15).

The angular frequency distribution of each term on the right side of Expression (15) is examined. As is clear from FIGS. 12 (a) and 12 (b), these are the products of two sidebands, so that the distribution has the same result as the "convolution" in statistics.

In FIG. 13, various sidebands a, b,
c and d are (a-1) to (d-1), (a-2) to (d-
In 2), the products ac, ad, bc, bd of the sidebands are (a
-3) to (d-3). Here, it is assumed that the sidebands of the amplitude modulation wave also exist flat between −ω _{H and} ω _H. From FIG. 13, products of sidebands ac, ad, bc, bd
It can be seen that each signal component of is as follows. ac: upper part of carrier angular frequency Ω ₁ (= Ω ₁ ) to 2ω _H
Has a main signal component (a-3). ad: lower −ω _H , upper ω across carrier angular frequency Ω _1.
There is a major signal component in _H (b-3). bc: lower-ω _H , upper ω with carrier angular frequency Ω ₁
There is a major signal component in _H (c-3). bd: Lower part of carrier angular frequency Ω ₁ (= Ω ₁ ) to 2ω _H
Has a main signal component at (d-3). As a result, the distribution of the composite modulated wave on the right side of Expression (13) becomes as shown in FIG. Here, the solid line shows the various sidebands shown in FIG. 13 and their products, and the broken line shows the distribution of the sidebands of the complex modulated wave existing around the carrier angular frequency Ω ₁ .

[0112] -2ω signal components of Figure 14 _H ~ω _H, -ω
_It is divided into _H to ω _H and ω _{H to} 2 ω _H, and the ratio of the power occupied in each is calculated. a) The signal component existing in −ω _{H to} ω _H is 50% of the carrier power and 42% of the sideband power b) The signal components existing in other than −ω _{H to} ω _H are the rest of the a). %.

From this result, it is found that even if the upper limit (ω _H ) of the primary sideband in the case of a single modulation wave is set as the cutoff frequency of the bandpass filter, the power of 92% of the composite modulation wave is included. Became clear.

Next, when the cutoff frequency of the band-pass filter is increased to make it possible to transmit up to 1.5 times, that is, 1.5 ω _H , the signal component existing within 1.5 (−ω _{H to} ω _H ) is calculated. , The result gets 98%. Therefore, the other signal components existed at 2%, and as a result, it was revealed that most of the signal components existed within 1.5 (-ω _{H to} ω _H ).

The above calculation is based on the assumption that the sideband characteristic of the modulated wave is flat. However, as is well known, the human speech spectrum is concentrated in a low frequency band.

FIG. 15 shows an example of the speech voice spectrum of a person. Here, the solid line shows the female voice, the broken line shows the male voice, and the dash-dotted line shows the average frequency distribution.
The long-term effective value (dB) per 1 Hz is the frequency (H
It can be seen that the focus is on the low part of z). Therefore, the frequency characteristic of the telephone signal also exhibits the frequency characteristic when the low frequency band of 0.3 kHz or less and the high frequency band of 3 kHz or more in FIG. 15 are cut off. Therefore, the telephone signal spectrum is also concentrated in the low frequency band, and near the high frequency of 3 kHz.
It can be seen that it is about 25 dB lower than that near 0.3 kHz. This also applies to a signal obtained by converting a telephone signal into TCM. When the same calculation as the above is performed using the sideband wave characteristic shown in FIG. 15, the following result is obtained. c) When the signal components existing in the transmission band 1.5 (-ω _{H to} ω _H ) are obtained, the result is 99.9% or more. d) The signal components existing outside the transmission band of 1.5 (-ω _{H to} ω _H ) are the rest of c) and are 0.1%.

Further, 99% or more is obtained even within the transmission band 1.33 (-ω _{H to} ω _H ). That is, it has been shown that it is sufficient to set B _fm-am = 1.33ω _H (16) as the required transmission bandwidth of the composite modulated wave.

This result also means that it is not necessary to insert a bandpass filter. Alternatively, it is shown that even if a bandpass filter having a narrower band characteristic is inserted to avoid adjacent channel interference, the transmission characteristic is not so badly affected.

The above results show that the TCM is transmitted from the radio base station 30.
It was a case of sending out a telephone signal. It will be described that when the TCM telephone signal is transmitted from the mobile wireless device 100, the modulated signal is further concentrated near the carrier wave. In this case, for example, (I ₀₁ / n) C of the first term on the right side of Expression (8) is used.
Only the signal indicated by ₁ will be transmitted to the radio base station 30. As is clear from the first term on the right side of the equation (8), it can be seen that the TCM-converted telephone signal spreads widely on the frequency axis. That is, a number of subcarriers equivalent to the switching angular frequency p of the time piece signal constituting the TCM signal (± p, ± 3 around the carrier angular frequency Ω ₁ are equivalent).
, p) ± 5p, ..., and the TCM-converted telephone signal spreads widely on the frequency axis due to the large number of subcarriers. For example, p is 50Hz
(= 2π × 50), the first subcarrier has an amplitude of ⅓ of the main carrier on both sides of the carrier angular frequency Ω ₁ of ± 2π × 50, and is mainly on ± 3p, ± 5p, ... 1 / of carrier wave
It has an amplitude of 5, 1/7, ..., 1 in the vicinity of ± 3 kHz.
It will have an amplitude of / 120. However, in an actual radio circuit, when modulating a carrier wave by a TCM telephone signal, a harmonic component is removed in advance through a band pass filter and a fundamental component is amplified. Therefore, the energy of the modulated signal is extremely small in the vicinity of ± 3 kHz and is concentrated in the vicinity of the carrier wave.

(C) Calculation of Frequency Effective Utilization Next, the spread of the sideband in the case of performing the above-mentioned single modulation without taking the complex modulation as in the present invention will be explained and both will be compared.

A case where a carrier wave is frequency-modulated by two TCM-converted telephone signals will be described. The highest frequency of the signal included in the TCM composite signal is 1.33 (ω _H + p). Therefore, as the required bandwidth of the modulated wave, B _2fm = 1.33 (2ω _H + p) (17)

The equations (16) and (17) are compared. Since p is smaller than ω _H and is ignored, the equation (16) is obviously smaller than the equation (17), and is about half the size. That is, the frequency effective utilization rate of the present invention is about twice as large as that of the conventional method.

From the above, it was proved that the present invention generally has a higher frequency effective utilization rate than the conventional method. Next,
Further, if TCM is used without increasing the signal compression ratio, the time slot length is lengthened and the amount of information that can be transmitted is reduced. Therefore,
If the information amount of the person who performs the complex modulation is reduced, the result is exactly the same as the comparison between the equations (16) and (17). Therefore, also in this case, it is proved that the present invention has a higher frequency effective utilization rate than the conventional method.

The composite modulation described above is a combination of frequency modulation and amplitude modulation. For complex modulation, a combination of frequency modulation and frequency modulation, or amplitude modulation and amplitude modulation is also possible. However, in this case, it is necessary to pay attention so that the frequency bands of the signals do not overlap each other.

Finally, the case of a composite signal composed of three or more signals such as a TCM-converted telephone signal, a fax signal, and a data signal will be described.
One way of implementing complex modulation is to further modulate the doubly modulated radio signal. In another method, when the maximum frequency of data is ω _q , if ω _m = ω _n + ω _q , the signal is modulated with a TCM-converted telephone signal once, and then a composite signal of a fax signal and a data signal, There is a method of further modulation. This method can be used practically because the same carrier wave is only subjected to two-time composite modulation, and the decrease in the effective frequency utilization rate is very small.

(3) System Design When Communication Signal Has Multiple Load Gain In the above description, the case where the system is designed using the TCM signal without considering whether the communication signal has multiple load gain is shown. .. However, according to Document 3, it is proved that a signal obtained by converting an analog telephone signal into a TCM signal has a multiple load gain. Therefore, also in the present invention, when a signal obtained by converting an analog telephone signal into a TCM signal is used, the signal level to the modulator of the transmission section may be determined in consideration of the multiple load gain. As a result, the transmission power can be reduced by an amount corresponding to the multiple load gain, and the frequency can be effectively used. In the following, referring to Reference 3, nCM multiplex TCM (frame length T)
When the multiple load gain (denoted by αdB) of the analog telephone signal (highest frequency f _h ) is calculated, it is the same as the multiple load gain of the n ′ multiple FDM (frequency division multiplex) signal given by the following equation. .. n '= n / (2Tf _h )

Next, regarding an analog image signal, there is no publicly known document that clearly explains whether or not it has a multiple load gain. However, it may be considered that the analog image signal has a multiple load gain similar to that of the analog telephone signal by creating the time difference image signal as described above. Therefore, the number of multiplexed image signal n, the maximum frequency and r _h, the multi-load gain obtained this time and BetadB. On the other hand, assuming that the time of one frame when transmitting the above image signal as the TCM signal is the same as the above (T), the multiplexing load when one image signal is accommodated in each time slot is loaded. The gain becomes equal to the multiple load gain β of the frequency division multiplex image signal having the multiplex number p ′ determined by the value p ′ = n / (2r _h T _t ).

Now, it will be described below that the present invention works extremely effectively for communication such as a videophone which uses voice and image signals at the same time for communication.

FIGS. 16 to 21 show a receiver 137 (FIG. 18 (Fig. 18 (Fig. 18) included in a mobile radio 100B (Fig. 16) and a radio base station 30B (Fig. 17) for explaining another embodiment of the present invention. a)), wireless reception circuit 35 (FIG. 18B), speed restoration circuit 138-2, image terminal unit 102 and speed conversion circuit 131-2 (FIG. 19), wireless transmission circuit 132 (FIG. 20) and wireless transmission. 22 shows a detailed configuration of the circuit 32B (FIG. 21). 16 to 21 will be described focusing on the points different from the corresponding FIGS. 2 and 3.

The details of the mobile wireless device 100B are as shown in FIG. 16, that is, the telephone section 101 which is one telephone terminal.
And one image terminal unit 102,
INS of NTT, ISDN for public telephone lines in Japan
For 64 services, 64 + 64 + 16 kb / sec
This is equivalent to using one telephone line and one image line.
In FIG. 16, from the wireless base station 30B to the mobile wireless device 100
B to composite signal (TCM telephone signal is frequency modulated, TCM
The image signal is assumed to be amplitude-modulated). This signal is demodulated by the receiving unit 137.

FIG. 18A shows a detailed circuit configuration of the receiving section 137 of the mobile wireless device 100B. The wireless composite modulation signal received by the antenna section is applied to the reception section 137 via the reception mixer 136 and is divided into two parts, and a part of the amplitude modulation signal reception section 151 operates by receiving the timing signal from the timing generator 142. Further, the other part is input to the frequency modulation signal receiving section 152 which operates by receiving the timing signal from the timing generator 142.

The TCM-converted telephone signal is demodulated here, and its output is input to the speed restoration circuit 138-1.
Then, here, the signal is expanded in time, the original signal of the telephone is restored and sent to the telephone unit 101.

Another part of the output of the reception mixer 136 is input to the frequency modulation signal receiving section 152 and the image signal converted into the TCM is demodulated here, and this output is the speed restoration circuit 138.
-2 is input. Then, here, the signal is temporally expanded to restore the original signal of the image and sent to the image terminal unit 102. As described above, since the image signal sent as the wireless signal is the time difference image signal, it is necessary to use the circuit shown in FIG. 19 to restore the original image signal.

FIG. 19 shows an image signal speed restoration circuit 138.
-2, speed conversion circuit 131-2 and image terminal unit 10
2 shows the internal configuration of the wireless reception circuit 13 from the right side.
The compressed time difference image signal (difference signal) from 5-2 is input. This input signal is input to and stored in the image signal storage circuit 161-1 or 161-2 for each time slot (each TCM frame unit) by the switch 165. The timing of switching the terminals a and b of the switch 165 is performed by a signal from the timing generator 142. Then, the signal stored here is read out and restored to the original image signal speed by the time expansion circuit 162-1 or 162-2. Then, this restored image signal is still in the form of a time difference image signal, and the image signal is generated by switching the terminals a and b of the switch 166-1 or 166-2 (this timing also depends on the signal from the timing generator 142). Reproducing circuit 163-1 or 1
It is input to 63-2. Here, the time difference image signal (difference signal) is added to the signal in the time slot of the immediately preceding frame, and the original image signal for one frame is reproduced. Then, by switching the terminals a and b of the switch 167 (this timing also depends on the signal from the timing generator 142), the image signal reproducing circuit 163-1 or 1
The output of 63-2 is taken out alternately, and the image terminal unit 102
Is displayed on the image display circuit 102-1.

The internal configuration of the image terminal unit 102 is shown on the left side of FIG. 19, and the control unit 140 and the image terminal control circuit 1 are shown.
Control signals are exchanged between 02-3. Further, the image display circuit 102-1 and the image transmission circuit 102-2
Operates by receiving a signal from the clock recovery circuit 141.

The lower part of FIG. 19 shows the internal structure of the speed conversion circuit 131-2. The image signal output from the image transmission circuit 102-2 of the image terminal unit 102 is the switch 175.
Thus, the image signals are input to and stored in the image signal storage circuit 171-1 or 171-2 for each frame. The timing of switching the terminals a and b of the switch 175 is performed by a signal from the timing generator 142. The signal stored here is read out, and the switch 17
Switching between the terminals a and b of 6-1 or 176-2 (this timing also depends on the signal from the timing generator 142)
Is input to the difference signal generation circuit 172-1 or 172-2, and the image signal is converted into a time difference image signal by subtracting (taking a difference) from the image signal of the immediately preceding frame. Then, the converted time difference image signal is input to the time compression circuit 173-1 or 173-2. Then, by switching the terminals a and b of the switch 177 (this timing also depends on the signal from the timing generator 142), one time slot of the TCM signal (TCM).
1 is given for each frame unit)
32-2.

On the other hand, a composite signal (TCM telephone signal is frequency-modulated, transmitted from the mobile radio 100B to the radio base station 30B).
TCM image signal is amplitude modulated)
The telephone signal created in 01 is sent to the speed conversion circuit 131-1. Then, here, the temporal compression of the signal is performed, and T
It is converted into a CM signal (however, the number of multiplexed channels is 1 channel). The TCM-converted telephone signal is sent to the transmission unit 134.

FIG. 20 shows the internal structure of the wireless transmission circuit 132. The telephone signal is input from the speed conversion circuit 131-1 to the frequency modulator 146 and frequency-modulated. The signal level at this time naturally takes into account the above-mentioned multiple load gain (normally a value obtained when the wireless base station 30B is mounted on all channels, the above-mentioned α dB), and the modulation depth is TC.
It is deeper than the signal that is not converted to M. After being frequency-modulated with such a signal level, the modulated wave is sent to the transmission mixer 133.

The image signal (in the form of a time difference image signal) created by the image terminal unit 102 is sent to the speed conversion circuit 131-2. Then, here, the signal is temporally compressed and converted into TCM (however, the number of multiplexed signals is one channel).
It is converted into an image signal. The image signal converted into TCM is sent to the transmission unit 134. In the transmitter 134, the amplitude modulator 14
4 and is amplitude-modulated. The signal level at this time naturally takes into consideration the above-mentioned multiple load gain (normally the value obtained when all channels are mounted in the radio base station 30B, the above-mentioned α dB), and the modulation depth is a signal that is not TCM-converted. Get deeper. After being frequency-modulated with such a signal level, it is sent to the transmission mixer 133. The timings of these telephone and image signals are adjusted at the same time, and the transmission mixer 133 uses the frequency-modulated TCM.
The modulated telephone signal and the amplitude-modulated TCM-converted image signal are mixed, and one composite modulated wave having the designated carrier frequency is sent from the antenna to the radio base station 30B.

In the radio base station 30B, the TCM composite signal (T
The CM telephone signal is frequency-modulated and the TCM image signal is amplitude-modulated efficiently.
0), and T that came in from the ordinary telephone / image network
The CM composite signal is sent to the mobile wireless device 100B that communicates oppositely.

Now, assume that a composite signal is sent from the mobile radio device 100B to the radio base station 30B. This signal is received by the wireless reception circuit 35. FIG. 18B shows the internal configuration of the wireless reception circuit 35. The output of the reception mixer 61 is divided into two, and a part of the output is input to the frequency modulation signal reception unit 63 and the TCM-converted telephone signal is transmitted here. It is demodulated and this output is input to the signal selection circuit group 39a. here,
A signal for each mobile radio device 100B is selected and sent to the signal speed restoration circuit group 38a. Signal speed restoration circuit group 38a
In TCM, each telephone signal converted to TCM is expanded in time to restore the original telephone signal and is sent to the switch group 83.

Another part of the output of the reception mixer 61 is input to the amplitude modulation signal reception section 62 and converted into TCM (time difference).
The image signal is demodulated here, and this output is input to the signal selection circuit group 39b. Here, a signal for each mobile radio device 100B is selected and sent to the signal speed restoration circuit group 38b. In the signal speed restoration circuit group 38b, each TCM (time difference) image signal is temporally expanded to restore the original signal of the image and sent to the switch group 83.

Next, the composite modulated signal wave transmitted from the radio base station 30B to the mobile radio device 100B will be described.
In FIG. 17, a communication signal 22 from an ordinary telephone / image network
-1 to 22-n enter the switch group 83 via the signal processing unit 31. The switch group 83 separates the telephone signal and the image signal, and the telephone signal is sent to the signal speed conversion circuit group 51a. The signal speed conversion circuit group 51a performs time compression of the signal and converts it into a TCM-converted (however, the maximum number of multiplexing is n channels) telephone signal. The TCM-converted telephone signal is sent to the signal allocating circuit group 52a, and a time slot is allocated to each mobile wireless device 100B communicating with each other, and then sent to the wireless transmitting circuit 32.

FIG. 21 shows another embodiment 32B of the internal configuration of the wireless transmission circuit 32. There are two carrier frequency sources 37-1 and 37-2 on the left side, and the angular frequency Ω _a ,
Outputting carrier wave of Ω _b . This carrier frequency source 37-
The carrier wave from 1 is input to the frequency modulator 36 that operates under the control of the control unit 40, and is frequency-modulated by the TCM-converted telephone signal from the signal allocation circuit group 52. The signal level at this time naturally takes into consideration the above-mentioned multiple load gain (normally a value obtained when all channels are mounted in the radio base station 30), and the modulation depth is deeper than that of a signal not converted into TCM. Become. After being frequency-modulated with such a signal level, it is sent to the transmission mixer 33. On the other hand, the carrier wave from the carrier frequency source 37-2 is input to the amplitude modulator 34 which operates under the control of the control unit 40. The image signals (in the form of time difference image signals) separated by the switch group 83 are sent to the signal speed conversion circuit group 51b.
In the signal speed conversion circuit group 51b, the signals are temporally compressed and converted into TCM image signals (however, the maximum number of multiplexing is n channels). The TCM-converted image signal is sent to the signal allocation circuit group 52b, and each mobile radio device 10 communicates with each other.
After a time slot (however, the time slot number is the same as the telephone signal) is assigned to each 0, the wireless transmission circuit 3
2B (FIG. 21) and is amplitude-modulated by the amplitude modulator 34. The outputs of the above two modulators are input to the transmission mixer 33, where the output frequency is converted into Ω ₁ = Ω _a + Ω _b , and at the same time, the composite modulation wave that has undergone frequency modulation and amplitude modulation is output. .. It should be noted that the timings of these same telephone / image composite signals are adjusted at the same time, and two modulation signals having the same time and the same signal length come in to the transmission mixer 33 when viewed corresponding to the channels. It will be. In the transmission mixer 33, the frequency-modulated TCM is used.
A composite modulated wave having a carrier frequency in which the deciphered telephone signal and the amplitude-modulated TCM-decoded image signal are mixed is sent from the antenna to each mobile radio device 100B.

Next, a characteristic of the system to which the present invention is applied is that a composite signal such as a telephone and an image is processed as one signal as a radio modulated wave. In the conventional method, when a plurality of communication signals are used for communication, two time slots in the same frame are used or one time slot is accommodated. In the former case, the signal transmission time becomes long, and in the latter case, the signal exclusive frequency bandwidth becomes large. Therefore, it can be seen that the present invention is extremely effective for effective use of frequencies.

In addition, since the multiple load gain of the telephone / image signal is used to increase the depth of modulation,
This amount of transmission power (to be exact, a value obtained by comparing the multiple load gain of the telephone signal and the multiple load gain of the image signal, and subtracting about 3 dB from the smaller value)
Can only be reduced. That is, it is effective for power saving.

A further advantage of the system to which the present invention is applied is that the system can be operated easily without significantly increasing the communication control capability. That is, since the telephone and the image can be transmitted in the same time slot, it is not necessary to enhance the communication control capability as compared with the case of transmitting them separately.

[0148]

[Effects of the Invention] ISDN expected to be introduced worldwide in the future
There are non-telephone terminals such as telephones, facsimiles, images, and data as communication terminals of the times, and it is assumed that these terminals are used at the same time using the same communication line. in this case,
By operating the present invention, there are advantages that effective use of frequencies can be measured, the system can be easily operated without significantly increasing the communication control capability, and that power saving is effective. The effect of the invention is extremely large.

[Brief description of drawings]

FIG. 1 is a conceptual configuration diagram showing a concept of a system of the present invention.

FIG. 2 is a circuit configuration diagram of an embodiment of a mobile wireless device for explaining the principle of the present invention.

FIG. 3 is a circuit configuration diagram of an embodiment of a radio base station for explaining the principle of the present invention.

FIG. 4 is a time slot structure diagram for explaining time slots used in the system of FIGS. 1 to 3;

FIG. 5 is a spectrum diagram showing spectra of a call signal and a control signal.

FIG. 6 is a circuit configuration diagram for multiplexing a voice signal and a data signal.

FIG. 7 is a waveform diagram showing a radio signal waveform of a time slot.

FIG. 8 is a time slot structure diagram in the case of transmitting an image and a telephone signal in the same time slot.

FIG. 9 is a spectrum diagram showing spectra of a time-compressed speech signal and control signal.

10 is a flow chart showing a flow of operations of the system of FIGS. 1 to 3. FIG.

11 is a flow chart showing a flow of operation of the system of FIGS. 1 to 3 together with FIG.

FIG. 12 is a spectrum diagram showing spread of sidebands of a radio signal.

FIG. 13 is a spectrum diagram showing products of various signal components in a radio signal and sidebands thereof.

FIG. 14 is a spectrum diagram showing a distribution of a composite modulated wave in a wireless signal.

FIG. 15 is a spectrum diagram showing a spectrum of human conversation voice.

FIG. 16 is a circuit configuration diagram for explaining another embodiment of the mobile wireless device.

FIG. 17 is a circuit configuration diagram for explaining another embodiment of the radio base station.

FIG. 18 is a detailed circuit configuration diagram of a receiving unit which is a component of a mobile wireless device and a wireless receiving circuit which is a component of a wireless base station.

19 is a detailed circuit configuration diagram showing an embodiment of the speed restoration circuit, the image terminal unit, and the speed conversion circuit, which are the constituent elements of FIG.

FIG. 20 is a detailed circuit configuration diagram of a wireless transmission circuit that is a component of a mobile wireless device.

FIG. 21 is a detailed circuit configuration diagram of an embodiment of a wireless transmission circuit that is a component of a wireless base station.

[Explanation of symbols]

 10 Telephone Network 20 Gateway Switch 22-1 to 22-n Communication Signal 30 Radio Base Station 31 Signal Processing Unit 32 Radio Transmitter Circuit 33 Transmitter Mixer 34 Amplitude Modulator 35 Radio Receiver Circuit 36 Frequency Modulator 37 Carrier Frequency Source 38 Signal Speed Restoration Circuit group 38-1 to 38-n Signal speed restoration circuit 39 Signal selection circuit group 39-1 to 39-n Signal selection circuit group 40 Control unit 41 Clock generator 42 Timing generation circuit 51 Signal speed conversion circuit group 51-1 to 51-n signal speed conversion circuit 52 signal allocation circuit group 52-1 to 52-n signal allocation circuit 61 reception mixer 62 amplitude modulation signal reception unit 63 frequency modulation signal reception unit 91 digital encoding circuit 92 multiple conversion circuit 100, 100- 1 to 100-n mobile wireless device 101 telephone unit 102 image terminal unit 102-1 image display circuit 1 2-2 Image Transmission Circuit 102-3 Image Terminal Control Circuit 120 Reference Crystal Oscillator 121-1, 121-2 Synthesizer 122-1, 122-2 Switch 123 Transmission / Reception Intermittent Controller 131 Speed Conversion Circuit 132 Wireless Transmission Circuit 133 Transmission Mixer 134 Transmitting unit 135 Radio receiving circuit 136 Receiving mixer 137 Receiving unit 138 Speed restoring circuit 141 Clock regenerator 142 Timing generator 144 Amplitude modulator 146 Frequency modulator 147-1, 147-2 Carrier frequency source 151 Amplitude modulation signal receiving unit 152 Frequency Modulation signal receiving unit 161-1, 161-2 Image signal storage circuit 162-1, 162-2 Time expansion circuit 163-1, 163-2 Image signal reproduction circuit 165, 166-1, 166-2, 167 switch 171- 1,171-2 Image signal storage circuit 172-1, 172-2 Difference signal creation circuit 173-1, 173-2 Time compression circuit 175, 176-1, 176-2, 177 switch 182 ID information collation storage unit

Claims (1)

Claim: What is claimed is: 1. A radio base means (30) that covers a plurality of zones to form a service area, and a radio base means that moves across the plurality of zones and communicates with the radio base means. Barrier exchange means (20) for exchanging communications with each mobile radio means (100) using radio channels carrying time-compressed delimited signals in time slots of a frame structure for In the time division communication method of mobile communication using and, in the angle modulation and the amplitude modulation based on the multiple load gain of the first communication signal among the plurality of kinds of communication signals that are temporally compressed and divided. Of the plurality of types of communication signals to be used as a modulated signal to obtain a first modulation signal. A time division communication method for mobile communication in which one of an angle modulation and an amplitude modulation is modulated based on the gain to obtain a second modulated signal.