JPH0226421A - Time division communication system in mobile communication - Google Patents

Abstract

PURPOSE:To effectively use a frequency by using the same radio channel between another moving radio machine and a radio base station and setting an independent radio line without exerting a bad influence on the communication between an already communicating moving radio machine and the radio base station. CONSTITUTION:While one moving radio machine 100 communicates with a radio base station 30, when another moving radio machine 100 transmits to the radio base station 30, the moving radio machine 100 which desires communication newly is given, in the radio channel already in use, an unused one among time slot series, in case of a telephone signal, and is given necessary plural time slot series in case of high-speed data or a picture signal, and the communication between it and the radio base station 30 can be made. Consequently, the communication can be made without plural communications disturbing one another and without the communication of itself being badly influenced. Thus, a system whose frequency use efficiency is high can be constructed.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to integrated 5erv
The present invention relates to a time-division communication system for wireless communication channels in mobile communication for providing a variety of communication signals suitable for the era of mobile communication.

More specifically, a radio channel is given, and one of the many mobile radios in the service area uses this to set up a radio link and communicate with the opposing radio base station. When another mobile radio device wishes to communicate using the same radio channel, the communication between the mobile radio device and the radio base station that is already in communication is not adversely affected. The present invention relates to a time division communication system using the same radio channel that makes it possible to set up an independent radio line between the radio base station and the radio base station using the same radio channel.

[Prior Art] In conventional mobile communications, it has been adopted, for example, in the automobile system of NTT (Nippon Telegraph and Telephone Corporation) in the commercial Y-bis. This will be explained with reference to FIG. A certain wireless base station 13 has a zone 14 which is its service area.
A plurality of radio channels are allocated to simultaneously communicate with a plurality of mobile radio devices 15 mounted in each of the many automobiles within the vehicle. On the other hand, 5, each mobile radio device 15 selects and uses one of the many radio channels (multichannel ↑
・Functionality that allows access (referred to as ``channel access'') is provided. When communicating with the radio base station 13, the mobile radio 11
5 communicates a control signal via the radio base station 13 to the radio line control station 12 which determines the use of radio channels of a large number of radio base stations 13, and determines the call channel number to be used for communication according to instructions from there. The system is configured to communicate with subscribers of the telephone network 10 via an exchange 11 including a switch SW.

[Problem to be Solved by the Invention] In this case, if the number of radio channels provided to a certain radio base station for calls is 10, the number of radio channels provided to a certain radio base station for calls is 10, It is possible to allocate separate wireless channels to communication requests, so it is possible to make a call, but for the call request from the mobile wireless device that made the 11th request, it is possible to allocate separate wireless channels. Unable to make calls (lost call) due to lack of wireless channel
It became. The above was an example of using a wireless channel to transmit an analog signal, but even when audio is digitally modulated, single channel per carrier (
Sinale Channei per Carrie
r) SCPC, that is, a system in which one telephone (communication) signal is carried on each carrier wave and transmitted, still has the above-mentioned unresolved problems.

[Means for solving the problem] If the bandwidth of a telephone signal is 1, a signal having m times the bandwidth is transmitted using m out of n+m time slots included in each frame. In order to a signal allocation means for serial output; a wireless transmission means for sending out the output of the signal allocation means as radio waves; A wireless receiving means for receiving radio waves sent at twice the high speed, and a system for receiving the output of the wireless receiving means and converting the signals included in the side time slots of each frame into parallel signals. and a signal speed restoring means for receiving (discarding) each of the i-divided signals from the signal selecting means and restoring them to a continuous signal; a wireless receiving means for receiving the signals included in the m time slots included in each frame out of the wireless radio waves; speed recovery means for restoring m segmented signals into a continuous signal; and for converting the speed of a signal to be transmitted having a bandwidth of 1 times the bandwidth of a telephone signal by a factor of n/i. A mobile radio comprising: speed converting means; and wireless transmitting means for transmitting the output of the speed converting means as radio waves using i time slots out of n time slots in each frame. Means is provided so that the mobile radio means and the general telephone network can communicate via a barrier exchange means.

[Operation] A radio base station and a large number of mobile radio devices exist within its service area, and in order for any number of mobile radio devices to be able to communicate with the radio base station, one radio channel is For telephone signals, one of these time slot sequences is selected; for high-speed data or image signals, the required time slot sequence is selected. A system was constructed that could communicate using this technology. If one mobile radio device is communicating with a radio base station and another mobile radio device sends a message to this radio base station, the mobile radio device that newly wishes to communicate will be sent to the radio channel that is already in use. In the case of a telephone signal, one unused time slot series is given to the time slot series, and in the case of high-speed data or image signals, a plurality of time slot series necessary for each are given, and communication with the wireless base station is performed. By enabling communication between the groups, it is possible for the plurality of communication groups to perform communication without interfering with each other and without adversely affecting their own communication.

[Embodiment] FIG. 1A, FIG. 1B, and FIG. 1C show a system configuration for explaining an embodiment of the present invention.

In FIG. 1A, 10 is a general telephone network, and 20 is a gateway exchange for connecting the telephone network 10 and a wireless system. 30 is a wireless base station and a barrier switch 20
It includes an interface with the mobile radio, a circuit that converts the signal speed, a circuit that allocates and selects time slots, a control unit, etc.
00 (100-1 to 100-n>) and has a wireless transmitting/receiving circuit that transmits and receives wireless signals.

Here, between the barrier switch 20 and the wireless base station 30,
There are transmission lines for transmitting communication signals 22-1 to 22-n including communication signals of communication channels CH1 to CHn and control signals.

FIG. 1B shows a mobile radio Ii! communicating with a radio base station 30! 5100 circuit configuration is shown.

Received signals such as control signals and call signals received by the antenna section enter a radio receiving circuit 135 that includes a receiving mixer 136 and a receiving section 137, and the output communication signal is sent to a speed recovery circuit 138, a control section 140, and a clock. The signal is input to the regenerator 141. The clock regenerator 141 regenerates the clock from the received signal and sends it to the speed conversion circuit 131.
Speed restoration circuit 138. The signal is applied to the control section 140 and the timing generator 142.

The speed recovery circuit 138 calculates the speed (pitch in the case of an analog signal) of the compressed and segmented communication signal in the received signal.
is restored and input as a continuous signal to the terminal section 102 including the telephone section and the broadband terminal section, and to the control section 140. Terminal section 102 including a telephone section and a broadband terminal section
The communication signal output from the transmission mixer 133 and the transmission section 134 divides the communication signal into predetermined time intervals in the speed conversion circuit 131, increases the speed (pitch in the case of an analog signal) to high speed (compression), and sends the communication signal to the transmission mixer 133 and the transmission section 134. The transmission signal is applied to the wireless transmission circuit 132 including the antenna unit, and the transmission signal is sent out from the antenna section and received by the wireless base station 30.

In this timing generator 142, the clock regenerator 14
1 and a control signal from the control section 140, the transmission/reception intermittent controller 123. It supplies necessary timing to the speed conversion circuit 131 and speed restoration circuit 138.

This mobile radio R100 has a synthesizer 121.
-1 and 121-2, and selector switches 122-1, 1
22-2, and a transmission/reception intermittent controller 123 that generates signals for switching the changeover switches 122-1 and 122-2, respectively.
1-2 and the transmission/reception intermittent controller 123 are controlled by the control section 140. Each synthesizer 121-1, 12
1-2 is supplied with a reference frequency from a reference crystal oscillator 120.

A wireless base station 30 is shown in FIG. 1C.

N-channel communication signal 22-1 with gateway switch 20
22-n are connected to a signal processing unit 31 forming an interface through a transmission path. Now, the communication signals 22-1 to 22-n sent from the barrier switch 20 are sent to the wireless base station 30.
The signal is input to the signal processing section 31 of. The signal@processing section 31 is equipped with an amplifier for compensating for transmission loss.
A so-called 2-wire to 4-wire conversion is performed. That is, the input signal and the output signal are mixed and separated, and the input signal from the barrier switch 20 is sent to the signal speed conversion circuit group 51. Further, the output signal from the signal speed restoration circuit group 38 is sent to the barrier exchange 112 by the signal processing unit 31 using the same transmission path as the input signal.
Sent to 0. Among the above, the input signal from the gateway exchange 20 is input to the signal speed conversion circuit group 51 including many signal speed conversion circuits 51-1 to 51-n, and is subjected to speed (pitch) conversion at predetermined time intervals. . In addition, for the signal transmitted from the radio base station 30 to the gateway exchange 20, the output of the radio reception circuit 35 is input to the signal speed restoration circuit group 38 via the signal selection circuit group 39, and is speed (pitch) converted. The signal is input to the signal processing section 31.

Now, the control of the radio reception circuit 35 or the output of the call signal is performed by a signal selection circuit 39 that selects a signal for each time slot.
-1 to 39-n is input to the signal selection circuit group 39,
Here, telephone signals are separated corresponding to each communication channel C+-+1 to CHn. After this output undergoes signal speed (pitch) restoration in a signal speed restoration circuit u38 including signal speed restoration circuits 38-1 to 38-n provided for each channel, it is input to the signal processing unit 31. After undergoing 4-wire to 2-wire conversion, this output is sent as a communication signal 22-1 to the barrier switch 20.
~22-Sent as self.

Next, the functions of the signal speed conversion circuit group 51 will be explained.

By storing input signals such as audio signals and control signals divided into a certain length of time in a memory circuit, and changing the speed when reading them out, for example, reading them out at a speed 15 times faster than when overwriting the memory, the signal can be read out. It becomes possible to compress the time length. The principle of the signal speed conversion circuit group 51 is the same as when playing back audio recorded by a tape recorder at high speed, and in reality, for example, a CCD (Char
gecoupled DeViCe), B B
D (Bucket Br1Oade[)eVice
), and the memory used in television receivers and tape recorders that compress or expand the time axis of conversation can be used (References: Koita et al. “Compressing the time axis of conversation /Extending Tape Recorder'° Nikkei Electronics, July 26, 1976, pp. 92-133>.

The circuit using COD or BBD exemplified in the signal speed conversion circuit group 51 can be used as it is in the signal speed restoration circuit group 38 as described in the above-mentioned literature. This can be achieved by making the reading speed slower than the writing speed in response to a timing signal from a timing generator 42 that generates timing based on the clock and a control signal from the control unit 40.

Control or telephone signals outputted from the barrier switch 20 via the signal processing section 31 are input to the signal speed conversion circuit group 51, and after speed (pitch) conversion processing is performed, signals are assigned to each time slot. It is applied to the signal allocation circuit group 52. This signal C1 circuit group 52 is a buffer memory circuit, which stores one section of high-speed signals output from the signal speed conversion circuit group 51, and outputs signals from the timing generation circuit 42 given by instructions from the control section 40. Using the timing information, the signal in the buffer memory is read and transmitted to the wireless transmission circuit 32. When viewed in terms of channels, this timing information is arranged in series without overlapping in chronological order, and if the control signals or telephone signals described later are fully implemented, it may be necessary to use continuous signal waves. It becomes like this.

The state of this compressed signal is shown and explained in FIGS. 2A and 2B.

The output signal of the signal speed conversion circuit group 51 is sent to the signal assignment circuit group 5.
2 and are given time slots in a predetermined order. Figure 2A (a> SDl, SD2
.SDn indicates that the speed-converted communication signals are allocated to each time slot.

Here, one time slot accommodates a synchronization signal and a control signal or a telephone signal as shown in the figure. If a telephone signal is not implemented, only the synchronization signal added by the communication path control section 81 is used, and an empty slot signal is added to the telephone signal portion. In this way, as shown in FIG. 2A (a), in the radio transmitter circuit 32, signals forming one frame in time slots SD1 to SDn are applied to the modulation circuit.

This time-series multiplexed signal is subjected to amplitude or angle modulation in the radio transmission circuit 32, and then is sent out into space from the antenna section.

When making or receiving a telephone call, the wireless base station 30
Regarding the transmission of control signals between the mobile radio device 100 and the mobile radio device 100, it is possible to use either within the telephone signal band or outside the telephone signal band.

Figure 3A shows these frequency relationships. That is, the same (a
) is an example of an out-of-band signal, as shown in the figure, the low frequency side (250Hz) and the high frequency side (3850) - IZ
) can be used. This signal is used, for example, when it is desired to send a control signal during a call.

FIG. 3A (b) shows an example of an in-band signal, which is used when making and receiving calls.

Although the above examples were all tone signals, it is possible to transmit many types of signals at high speed by increasing the number of tone signals or by modulating the tone and making it into a subcarrier signal.

The above was a case of analog signals, but if a digital data signal is used as a control signal, it is also possible to digitally encode the audio signal and time-division multiplex the two to transmit. The circuit configuration of is shown in FIG. 3E. FIG. 3E shows an audio signal digital encoding circuit 9.
This is an example of a case in which the data signal is digitized at 1, multiplexed with a data signal by a multiplex conversion circuit 92, and applied to a modulation circuit included in the wireless transmission circuit 32.

Then, it is received by the opposing receiver, and the 3rd E
By performing the operation opposite to that shown in the figure, it is possible to extract the audio signal and the control signal separately.

On the other hand, the signal sent from the mobile radio device 100 is received by the antenna section of the radio base station 30 and input to the radio reception circuit 35. FIG. 2A (b) schematically shows this upstream input signal.

That is, time slot SU1. SU2. ...S
un is mobile radio 100-1.100-2°...,
100-n shows a transmission signal addressed to the wireless base station 30.

Also, each time slot su1. su2,...,su
If the contents of n are shown in detail, it consists of a synchronization signal and a control signal or a telephone signal, as shown at the lower left of No. 2A(b). However, the wireless base station 30 and the mobile wireless device 100
It is possible to omit the synchronization signal depending on the short distance between the two or the signal speed. Roughly speaking, the waveform of the radio carrier wave of the above-mentioned uplink radio signal within a time slot is shown schematically as shown in No. 28 (C).

Now, among the input signals that have arrived at the wireless base station 30, the control signal is immediately sent to the control unit 40 from the wireless receiving circuit 35.
added to. However, depending on the size of the speed conversion rate, it is also possible to apply the output of the signal speed restoration circuit group 38 to the control section 40 after the telephone signal has been subjected to similar processing. Further, telephone signals are applied to a signal selection circuit group 39.

A timing signal from a timing generation circuit 42 that generates a predetermined timing is applied to the signal selection circuit group 39 according to a control signal instruction from the control unit 40, and a synchronization signal and a control signal are generated for each time slot SU1 to Sun. The signal or telephone signal is output separately. Each of these signals is input to a signal speed restoration circuit group 38. This circuit is a speed conversion circuit 131 (
It has a function to perform the inverse conversion of FIG. 1B), thereby faithfully reproducing the original signal and transmitting it to the gateway exchange 20.

The manner in which signals are transmitted in the signal space according to the present invention will be explained below using the required transmission band and the relationship between this and adjacent wireless channels.

As shown in FIG. 1C, the control signal from the control section 40 is applied to the wireless transmission circuit 32 in parallel with the output of the signal allocation circuit group 52. However, depending on the size of the speed conversion rate, it is also possible to apply the signal to the wireless transmission circuit 32 from the output of the signal allocation circuit group 52 that has been processed in the same way as a telephone signal.

Next, as shown in FIG. 1B, the mobile radio 1100 also has a circuit configuration that is required when the communication path is one channel among the functions of the radio base station 30.

Original signal, for example, an audio signal (0.3KHz to 3.0KH2
) passes through the signal speed conversion circuit group 51 (Fig. 1C), the output side frequency A is as shown in Fig. 3B. In other words, as mentioned above, the audio signal is converted 15 times. If so, the frequency distribution of the signal is as shown in Figure 3B.
This means that the frequency is expanded to 4.5KHz to 45KHz. The figure shows a case where the control signals are simultaneously transmitted using the lower frequency band of the telephone signal. It is assumed that among these signals, a control signal (0.2 to 4.0 KH2) and a communication signal CH1 (15 to 45 KHz, expressed as SDl) are accommodated in a time slot, for example SDl. Other time slots SD2 to S[)n
The same is true for telephone signals contained in.

That is, time slot SDi (i=2°3, -
, n) accommodate a control signal (0,2 to 4.0KH2) and a communication signal CHi (4,5 to 45Kl-1z). However, the signals in each time slot are arranged in chronological order, and the signals in multiple time slots are not applied to the wireless transmission circuit 32 at the same time.

These telephone signals are sent to the wireless transmission circuit 32 along with control signals.
When added to the angle modulator included in the angular modulator, the required transmission band requires at least fo±45KH7. However, fC is the radio carrier frequency. If there are a plurality of wireless channels given to the system, the speed-up of the signal by the signal speed conversion circuit group 51 is limited to a certain value due to the limitations on these frequency intervals. The frequency interval of multiple wireless channels is f
,. , and the maximum signal speed due to the above-mentioned speed increase of the audio signal is fH, then the following inequality must hold between the two.

f > 2 f H ep On the other hand, in digital signals, audio is usually digitized at a speed of about 64 kb/s, so read by raising the scale on the horizontal axis in Figure 3B, which explains the case of analog signals, by about one digit. Although necessary, the relationship in the above equation also holds true in this case.

Further, the control signal input from the mobile radio device 100 to the radio base station 30 is input to the radio reception circuit 35, but a part of the output is input to the control unit 40, and the other part is input to the signal selection circuit group 39. The signal is sent to the signal speed restoration circuit group 38 via the signal speed restoration circuit group 38. After the latter control signal undergoes speed conversion (conversion to a low speed signal) that is completely opposite to that at the time of transmission, it becomes the same signal speed as that used in the general telephone network 10 and is transmitted via the signal processing section 31. Sent to barrier exchange 1m20.

Although the above explanation was an example of a telephone signal, a case will be described below in which a signal having a wider band than a telephone signal, such as high-speed data or an image signal, is transmitted.

In FIG. 1B, a wideband signal transmitted from the radio base station 30 passes through the antenna section, is demodulated by the receiving section 137, and is input to the speed restoration circuit 138.

As shown in FIG. 2C (a), the wideband signal uses, for example, three times as many time slots as the telephone signal, and is formed by a synchronization signal and a control signal or a wideband signal.

The positions of the time slots used are shown in Figure 2C (a).
As in, it is not necessary to use consecutive time slots, but may be discrete. However, in that case, it is necessary to provide a temporary storage circuit within the speed restoration circuit 138 and adjust the timing when reading signals from there so that the reproduced signal (original signal) is temporally continuous.

A control signal is included at the start of communication, indicating the type of signal, that is, a telephone signal or a broadband signal, and in the case of a broadband signal, indicating the broadband ratio m (integer) to the telephone signal. This signal is transmitted to the control section 140, and the control section 140, which has identified the type of signal, starts the timing generator 14.
2 and the transmission/reception intermittent controller 123 to start operation. That is, the timing generator 142 instructs the transmission/reception intermittent controller 123 as follows.

That is, time slot SD2~ of FIG. 2C (a>
Receive wideband signals SD2 to SD4 included in SD4,
Bandwidth signals transmitted from the own terminal unit 102 are transmitted using time slots SU2 to SU4 as shown in FIG. 2C (b) (assuming that the same type of wideband signals are sent in both directions).

As a result of the above operations, the mobile radio device 100
It becomes possible to receive the broadband signal sent from 0, and it becomes possible to perform processing such as display on the terminal unit 102.

Next, when the signal sent from the terminal unit 102 of the mobile radio device 100 is a wideband signal, the control signal notifies the radio base station 30 that the signal transmitted is a wideband signal prior to communication.

That is, in FIG. 1C, the above mobile radio device 100
The transmitted signal is received by the radio receiving circuit 35 and demodulated. The resulting wideband signal is
Since it is known by receiving the control signal that slots SU2 to SU4 are being used, start the operation of the signal selection circuits 39-2.39-3.39-4 in the signal selection circuit group 39. Ru. These outputs are sent to the signal speed restoration circuits 38-2, 38-3, and 38- of the signal speed restoration circuit group 38.
4, are restored to the original signal speed, and are input to the signal processing section 31. Here, signal speed restoration circuit 3
The signals of 8-2, 38-3 and 38-4 become one continuous wideband signal and are sent out from the trunk line with the gateway exchange 20 as, for example, a communication signal 22-2.

On the other hand, the broadband signal from the barrier exchange 120 is transmitted from the trunk line as a communication signal 22 - 2 and is added to the signal processing section 31 . When the signal processing unit 31 inspects the content of the signal and recognizes that it is a wideband signal, it temporally converts the signal into 3
Three signal speed conversion circuits 51-2 and 51-3 are divided and are chronologically continuous with respect to the signal speed conversion circuit group 51.
．． and 51-4 are used, and after contacting the mobile radio device 100 with a control signal and undergoing signal speed conversion, the signal assignment circuits 52-2, 52-3, 52- of the signal assignment circuit group 52 are used. 4, the signal is assigned three consecutive time slots, is guided to the radio transmission circuit 32, and is transmitted from the antenna section to the mobile radio device 100. After this is received by the mobile radio device 100, the speed is restored and inputted to the terminal section 102, making it possible to achieve the intended purpose.

The above is a case where a wideband signal is used in the communication system according to the present invention, and it will be explained below that, like a telephone signal, this does not have any adverse effect on other channels of the same system or signals in other slots of the same channel. Explain.

First, the value of the adverse effect on other time slots on the same channel is quantitatively as described later and can be ignored. In other words, when transmitting even a wideband signal, empty time slots are always used, and the required number of consecutive or discrete empty slots are used, and the frequency components contained in the slots are This is because, as will be described later, it is substantially equivalent to a telephone signal. Furthermore, if there is no free time slot, communication is not started or another channel that satisfies this condition is used.

Next, the state of the compressed signal transmitted to the wireless transmission circuit 32 of the wireless base station 30 is shown in FIG. 2C (a).

(b) and FIGS. 2D (c) and (d) for explanation.

In FIG. 2C(a), broadband signals from radio base station 30 are shown in time slots SD2-4. This shows a case where the broadband ratio of the broadband signal to the telephone signal is m=3, and it can be seen that three slots of the telephone signal are used. An actual wideband signal is, for example, 43
In the case of a kbps high-speed data signal, the telephone signal equivalent is 3
slot (carrier frequency interval 12.
5 KHz), and in the case of a 500 kbps image signal, it is necessary to set m to about 30. FIGS. 2C (a) and 2C (b) schematically show an example where m=3. FIG. 2D (d) shows the transmission waveform of the broadband signal from the wireless base 830 when time slots are used. As is clear from the figure, time slot SD
Although the envelope has a lower frequency than the waveform of the telephone signal in No. 1, the frequency components of the signal waveform within the envelope are almost the same as those of the telephone signal. This is because we took into consideration the wideband nature of the signal and slowed down the reading speed for that component. This has important implications for the amount of wireless interference on other wireless channels. If so, the amount of interference to other channels also depends on the time slot S.
This is equivalent to the telephone signal of D1, and provides evidence that, in the interferometer sieve described later, it is safe to consider that radio interference from broadband signals is also of the same level as the telephone signal.

Similarly, the method of transmitting wideband signals sent from the mobile radio device 100 to the radio base station 30 also uses time slots SU2 to SU4 shown in FIG. 2C(b). The received waveform of is as shown in FIG. 2D (C).

Therefore, in this case as well, it contains almost the same frequency components as the telephone signal of time slot SUI.
The influence exerted on telephone signals by other time slots is also about the same as that of telephone signals.

This will be explained from the viewpoint of frequency bands using FIG. 3C. In the figure, wideband signals are indicated by C)-12 to C)-4. Since it is a digital signal, it is difficult to display an analog signal, but since the signals of the other channels CH1 and CHn are analog, they are intentionally converted into analog signals and displayed for comparison. In this case, the frequency band (base band signal) for 3 channels of telephone signals is 300~
11000H2, indicating that 11500)-12 outside the band is used for the control signal during broadband signal transmission. The broadband signals shown in CH2 to CH4 in FIG.
1, but as a result, the frequency component of the wideband signal sent from the wireless transmission circuit 32 is
They are represented as SD2-4 in FIG. 3D. That is, although three time slots are used, the frequency components contained therein are almost the same as other speech signals (telephone signals). This is due to the fact that by using three signal speed converting circuits in the signal speed converting circuit group 51, the successive output speed of the signal is reduced to ⅓.

The above explanation deals with the case of transmission from the wireless base Q30, but the wideband signal transmitted by the mobile wireless device 100 taking the initiative will be described below.

The mobile radio device 100 constantly monitors reception (radio transmitter circuit 1
(Other than 32 are in operation), and as a result, the time
Slot SU2. It is recognized that SU3 and SU4 are empty slots l~. Three slots (m=3) are sufficient for the wideband signal transmitted from the mobile radio device 100 itself, and the control unit 140 uses the speed conversion circuit 131 to transmit a high-speed signal that is 1/3 as fast as that for telephone signals. instruct them to do so.

Further, the control unit 140 causes the transmission/reception intermittent controller 123 to prepare on/off operations of the switches 122-15 and 122-2 so that transmission can be performed in time slots SU2.5tJ3 and SU4.

Then, when the broadband signal from the terminal unit 101 is output,
The speed conversion circuit 131 performs the speed conversion described above, stores the output in a storage circuit built into the speed conversion circuit 131 in units of time slots, and outputs it to the wireless transmission circuit 132 at the timing instructed by the control unit 140. keep it as possible.

In addition, in order to receive the broadband signal transmitted from the wireless base station 30, the speed restoration circuit 138 restores the signal at one-third (m=3) the speed of restoring the signal speed of the telephone signal. However, the output is stored in the built-in storage circuit of the speed restoration circuit 138 in units of time slots,
At the timing instructed by the control unit 140, the signals of the three time slots are chronologically continuous to form one signal, and the signal is maintained in a state capable of being transmitted to the terminal unit 102.

Now, regarding the broadband signal transmitted from the mobile radio device 100, the type of signal, the broadband rate m, and the time slot number to be used are specified by a control signal at the time of starting transmission. The control unit 40 of the radio base station 30 that receives this inspects the status of the signal selection circuits 39-2, 39-3 and 394 corresponding to the time slot desired by the other party among the signal selection circuit group 39, and After confirming that the time slot 1 is available, the mobile radio 11100 is notified that the desired time slot 1 is available for use.

Similarly, the signal speed restoring circuits 38-2, 38-3, and 38-4 at the back of the signal speed restoring circuit group 3B are brought into operation, and the signal processing section 31 is set to the signal speed restoring circuits 38-2, 38-2, and 38-2. 38-3.384 is one wideband signal, and sends out a control signal to properly time the signals and mix them into a continuous signal. As a result, the wideband signal transmitted from mobile radio device 100 is successfully received by radio base station 30. On the other hand, a similar broadband signal transmitted from the radio base station 30 is also transmitted to the mobile radio device 1.
00 enables reception.

Next, the call originating/receiving operation of the system according to the present invention will be explained using telephone signals and broadband signals as examples.

(1) Call origination from mobile radio device 100 This will be explained using the flowcharts shown in FIGS. 4A and 4B.

When the mobile radio device 100 is powered on, the first
In the wireless receiving circuit 135 in Figure B, the downlink (wireless base station 30
→Mobile radio device 100) Starts capturing the control signal included in the radio channel (referred to as channel CHI). If the system is provided with multiple radio channels, i) the radio channel exhibiting the highest received input electric field);
A wireless channel (iii) that is instructed by a control signal included in the wireless channel; a wireless channel (hereinafter referred to as channel CH1) is in the receiving state. This is possible by capturing the synchronization signal within the time slot SDi shown in FIG. 2A(a). In the control unit 140, the synthesizer 121-
A control signal is sent to the synthesizer 122-1 to generate a local frequency that enables reception of the radio channel CH1, and the switch 122-1 is also fixed in the position of the synthesizer 121-1.

Therefore, when the handset of the telephone unit included in the terminal unit 102 is off-hook (starting a call) (S201, FIG. 4A)
The synthesizers 121-2 in FIG. 1B receive control signals from the control unit 140 to generate local frequencies that enable transmission of the wireless channel CHI. Also switch 1
22-2 is also brought down to the synthesizer 121-2 side and becomes fixed. Next, the terminal unit 1 uses the wireless channel CH1.
The calling control signal output from 02 is sent out.

This control signal uses the frequency band shown in FIG. 2A (b), and is transmitted using, for example, time slot Sun.

The transmission of this control signal is limited to the time slot Sun, and is sent in bursts, and no signal is transmitted during other time slots, so it does not adversely affect the communications of the network. However, if the speed of the control signal is relatively slow or the amount of information in the signal is large and cannot be accommodated in one time slot, the same time slot of the next frame will be displayed after one frame or roughly. - Transmitted using slots.

Specifically, the following method is used to capture the time slot Sun. As shown in FIG. 2A (a), the control signal transmitted from the radio base station 30 includes a synchronization signal and a subsequent control signal, and the mobile radio @ 100 receives the synchronization signal and then frames the frame. Synchronization becomes possible.

Furthermore, this control signal includes control information such as currently used time slots and unused time slots (empty time slot display). Depending on the system, the time slot so; <i=1.2°...,
n) may only contain synchronization and speech signals when they are being used by other communications; By receiving this control signal, mobile radio 1100 can know which time slot to use to send out the calling signal.

Note that if all time slots are in use,
It is not possible to make a call on this radio channel and it is necessary to sweep and search for another radio channel.

In other systems, there may be no empty slot indication in any of the time slots, in which case the following audio multiplex signals SD1, SD2 . ..., S
It is necessary to search for the presence of Dn one after another and check for empty time slots.

Now, returning to the main topic, the mobile radio device 100, which has received the control information sent from the radio base station 30 by one of the above methods, determines in which time slot it should send the call control signal. It is possible to make a judgment including the transmission timing.

Therefore, assuming that the time slot 5LJn for uplink signals is an empty slot, it is decided to use this empty time slot, and a call control signal is sent to the radio base station 30.
A burst control signal can be sent by extracting the necessary timing from the response signal.

If there is a call from another mobile radio at the same time, the calling signal will not be properly transmitted to the radio base station 30 due to call collision, and the operation will have to be restarted from the beginning, but this probability is When viewed as a system, this value is kept to a sufficiently small value. If call collisions are to be significantly reduced, the following method may be used. If the mobile radio 1100 finds an empty time slot in which it can make a call, it does not use the entire time slot, but uses only the first half for some mobile radios and the latter half for others. This is the way to do it. In other words, the time signal is used as a calling signal.
Divide the used portion of the slot into several types, use this to classify a large number of mobile radio devices into groups, and place one of the slots in each group.
This method gives the time period within one time slot.

Another method is to create many different frequencies for the control signal,
This is a method of dividing a large number of mobile wireless devices into groups and applying this to each group. According to this method, even if control signals of different frequencies are transmitted simultaneously using the same time slot, no interference will occur at the radio base station 30. The above two methods may be used separately, or when used together, the effects will increase synergistically.

Now, suppose that the calling control signal from the mobile radio device 100 is successfully received by the radio base station 30 and the ID (identification number) of the mobile radio device 100 is detected (8202). Search for a time slot.The time slot given to mobile radio 100 may be Sun, but just to be sure, perform a search.
In addition to 00, this is also used to accommodate simultaneous calls from other mobile radios, and to provide time slots suitable for service types and service classifications.

As a result, for example, if the time slot SDI is vacant, the mobile radio device 100 uses the time slot SD1 of the radio channel CH1 and uses the downlink control signal to transfer the time slot upstream (mobile radio device 100 → radio base station 30 )SUI.

and instructs to use the corresponding downlink (radio base station 30 → mobile radio device 100) SDI (3203
>. In response, the mobile radio device 100 transitions to a state in which it can receive data in the instructed time slot SD1, and at the same time, it shifts to a state in which it can receive data in the designated time slot SD1, and also changes the time slot 5UI, which is the time slot for the uplink radio channel corresponding to the downlink time slot SDI (FIG. 2A). (b)). At this time, the control unit 140 of the mobile radio device 100 operates the transmission/reception intermittent controller 123 to start operating the switches 122-1 and 122-2 (S204). At the same time, it sends a slot switching completion report to the wireless base station 30 using uplink time slot SU1 (5205) and waits for a dial tone (
S206>.

Time slot SU of the radio carrier of this upstream radio signal
The state of I is schematically shown in FIG. 2B (C). In addition to the time slot SUI, the wireless base station 30 also receives 5tJ as an uplink signal from other mobile wireless devices 100.
3 and Sun are included in one frame and sent.

The radio base station 30 that has received the slot switching completion report (
S207), sends a calling signal to the barrier exchange 20 (3208), and upon receiving this, the barrier exchange 1120 detects the ID of the mobile radio 100 and selects the necessary switch at the back of the switch group included in the barrier exchange 4120. Turn on (8
209>, sends a dial tone (8210, Figure 4B).

This dial tone is transferred by the wireless base station 30 (S211>, and the mobile wireless device 100 confirms that the communication path has been set (3212).

When transitioning to this state, the terminal section 10 of the mobile radio device 100
Since a dial tone is heard from the handset of the telephone set included in step 2, the dial signal begins to be sent. This dial signal is speed-converted by a speed conversion circuit 131 and is sent to a radio transmission circuit 13 including a transmission section 134 and a transmission mixer 133.
2 using uplink time slot SU1 (S213).

Thus, the transmitted dial signal is received by the radio receiving circuit 35 of the radio base station 30. This radio base station 30 has already responded to the calling signal from the mobile radio 100,
In addition to giving the time slot to be used, the signal selection circuit group 39 and signal allocation circuit group 5 of the wireless base station 30
2 is operated to receive the uplink time slot SUI, and the state has shifted to the state where the downlink time slot SDI signal is transmitted. Therefore, the dial signal transmitted from the mobile radio device 100 passes through the signal selection circuit 39-1 of the signal selection circuit group 39, and then is input to the signal speed restoration circuit group 38, where the original transmission signal is restored. The telephone signal 22-1 is sent to the barrier switch 2 as a telephone signal 22-1 via the signal processing unit 31.
0 (S214>, and a communication path to the telephone network 10 is set (S215>).

On the other hand, an input signal from the barrier switch 20 (initial control signal,
When a call is started, the telephone signal (telephone signal) undergoes speed conversion at the signal speed conversion circuit group 51 in the radio base station 30, and is then given a time slot SD1 by the signal allocation optical circuit 52-1 of the signal allocation circuit group 52. It is being Then, the time slot SD of the wireless channel downstream from the wireless transmission circuit 32
1 to the mobile radio device 100. In the mobile radio device 100, the time and time of radio channel CH1 are
It is on standby for reception in slot SD1 and is received by radio reception circuit 135, the output of which is input to speed restoration circuit 138. In this circuit, the original signal of the transmission is restored,
The information is input to the handset of the telephone unit included in the terminal unit 102. Thus, a call is started between the mobile radio 100 and a regular telephone within the regular telephone network 10 (82
16).

The call is terminated by on-hooking the receiver of the telephone unit included in the terminal unit 102 of the mobile radio device 100 (S217
), the end-of-call signal and the on-hook signal from the control unit 140 are sent from the wireless transmission circuit 132 to the wireless base station 30 via the speed conversion circuit 131 (S218),
The control unit 140 stops the operation of the transmission/reception intermittent controller 123, and switches the switches 122-1 and 122-2 to the synthesizer 121-1. f”j and the output end of 121-2.

On the other hand, in the control unit 40 of the radio base station 30, the mobile radio device 1
Upon receiving the end call signal from 00, the end call signal is forwarded to the barrier exchange 120 3219>, switch group (not shown)
The switch is turned off to end the call (S220>. At the same time, the signal selection circuit group 39 and signal allocation circuit group 52 in the wireless base station 30 are opened.

In the above explanation, control signals between the radio base station 30 and the mobile radio device 100 are controlled by the signal speed conversion circuit group 51. Although it was explained that the signal does not pass through the signal speed restoration circuit group 38, etc.,
This is for convenience of explanation, and communication can be carried out without any problems even through the signal speed conversion circuit group 51, signal speed restoration circuit group 38, control signal speed conversion circuit 48, and communication@processing section 31 in the same way as with telephone signals. be.

Although the above is a case where a call is made by a telephone from the mobile radio device 100, it is also possible to make a call by a broadband signal other than a telephone by adding the following conditions.

That is, at the start of a call, it is indicated that it is a broadband signal, it is indicated that the broadband ratio m to the telephone signal is indicated, and it is confirmed that there are at least m empty time slots in the same radio channel.

However, the number of empty time slots does not necessarily have to be m consecutively, and the total number of time slots in some places in one frame within the same channel may be m or more in any combination. Good to have. In this case, it is necessary for the partner wireless base station 30 communicating with the other party to temporarily store these received signals so that they become continuous signals when read out.

(2) Incoming call to mobile radio device 100 The mobile radio device 100 is on standby with the power turned on. In this case, as explained in the section regarding the call origination from the mobile radio device 100, the mobile radio device 100 is in a state of waiting to receive a downlink control signal of the radio channel CHI in accordance with the procedure defined by the system.

Assume that an incoming call signal to the mobile radio device 100 arrives at the radio base station 30 from the general telephone network 10 via the barrier switch 20. These control signals are transmitted as communication signals 22 to the control section 40 (FIG. 1C) via the signal speed conversion circuit group 51 and the signal allocation circuit group 52, in the same way as telephone signals.Then, the control section 40 An empty slot among the downlink time slots of the radio channel CH1 addressed to the radio device 100, for example, SDl, is used to transmit the ID signal of the mobile radio device 100, the incoming call signal display signal, and the time slot usage signal (from the mobile radio device 100). For example, SUL corresponding to SDI is used to transmit .

In the mobile radio device 100 that receives this signal, it is transmitted from the receiving section 137 of the radio receiving circuit 135 to the control section 140. In the control unit 140, this signal is transmitted to the own mobile radio device 10.
The terminal unit 102 confirms that it is an incoming call signal to 0.
At the same time, a ringtone is sounded from the telephone unit included in the
Indicated time slot SD1. The transmission/reception intermittent controller 123 is operated to stand by at SU1, and
The switches 122-1 and 122-2 are started to turn on and off. In this way, the state has shifted to a state in which calls can be made.

Although the above was a case of telephone signals, it is possible to receive calls using high-speed data or image signals as well.

However, the same conditions as explained when making a call are required.

Next, we will theoretically explain how this system can be used to perform signal transmission in good conditions without adversely affecting other wireless channels within the system. for that,
Upward transfer 1111 Radio device 100 transmits, radio base station 30
Take, for example, a radio signal (received by

First, assume that all uplink radio signals are empty lines, that is, all time slots are not used. The mobile radio @100 that wishes to make a call uses a control signal in the downlink radio channel, for example, time slot SD1, so that the mobile radio 100 can check the usable time slot of the uplink radio channel.
With a slot (for example, time slot SDI>) selected, a control signal (a telephone signal if a communication path is set) is sent from the radio transmission circuit 132 to the radio base station 30 in response to a signal from the timing generation circuit 142.

Similarly, if there is a call originating (terminating) from another mobile radio, a control or telephone signal is sent to the radio base station 30 as an uplink radio signal using another time slot on the same radio channel.

The signals included in the uplink radio channel explained above will be expressed mathematically.

The data or telephone signal (for signals in analog or digital format), which is the output signal (or control signal) of telephone unit 101 in FIG. 1B, can be expressed as follows.

μ(t)=, Σa−CO3(ωi 10θ1)1・11 Also, the control signal that exists outside the band is μ(t)=, Σa−cos(ωH 10θi)01=
m. 11 Here, a・ is the magnitude of the amplitude, ωi is the angular frequency of the signal,
θ· represents the phase when 1=0. m.

n represents a positive integer.

Next, the case of frequency modulation will be explained, but the present invention is similarly applicable to both phase modulation and amplitude modulation. When a carrier wave is frequency modulated using equation (1) or equations (1) and (2), the resulting modulated wave is: I=IQSinf(ω0μ(t)) d t=I
□S! n (ωt+5(1)) (3) or I = IoSin f (ω1μ(1)μo(t)
>dt=Iosin(ωt+5(t)+5o(t)>However, 5(t)+5o(1) shown in equation (4) represents a general form of transmission signal.

Now, using equation (3) or equation (4), the radio signal sent from the antenna of mobile radio device 100 is expressed by the following equation.

1= (101/n) [1+2F1(n/mπ))X
Sin (m7r/n)CO3mptlxsin (
C1t+s1m+5o1(t)) where n is the number of slots (equal time intervals) within one frame, p is the switching angular frequency, and m is a positive odd number.

Equation (5) is for mobile radio g11 using the same radio channel.
The transmission signal from 00 is one of the slots 1-0 in one frame, but all slots are filled with signals, that is, n mobile radios 100 are on the same radio channel. The mathematical expression of the signals included in the wireless channel when communication is in progress using

I-(Io1/n> [1+2i1(n/m7r))
xsin (mπ/n)cos mpt]xsin
(C1 + S1) + 5C1(t) ) ± (, I
02/n) [1+2 Σ (n/mπ) m=1 xsin (mπ/n> xcos mp (t-2π/ (np> ) ] xs
in (Ω2i+S2 (t) +5C2(t) )x
sin (mπ/n) xcos mp (t-4yr/ (np> ) ]x
s+n (Ω3t+53(t)+5C3(t))+(I
oo/n> (1+2Σ(n/mπ)) m=1 xs+n (mπ/n) xcos mp (t -2(n-1) yr/, (
np) ) ]xsin (Ω t+s (t) +
so, m )n where p is the switching angular frequency, m is a positive odd number, and the switching times for n input waves are equally spaced.

Also C1. C2,..., Ω. Although the carrier frequencies transmitted from each mobile radio device 100 are the same radio channel, different symbols are used because the carrier frequencies are slightly different. S.
(1) and S. The same applies to 1(t) (i=1.2°..., n).

When the right side of equation (6) is transformed, it becomes the following equation.

I = (L01/n > [S:n (Ω1t +
U 1 (t) )+(n/π) sin(π/n> x[cos((Ω −p)t+U1(t))−cos(
(Ω1+ p) t +U1 (t) ) ]+ (
n/3yr) sin (37r/n>x[cos((
C13p)t+U1 (j))cos ((Ω +3
p)t+U1(t))]]+(n15yr)sin (5yr/n)x[cos(
(C1-5p)t+U1(t))-cos((Ω +5
p> t+U1 (t)) ]] +・・・・・・ ]+(I
02/n> [sin (C2t+U2 (t) ]+
(n/π) sin(π/n> x[cos((C2-p)t+U2(1))-cos(
(C2+ p) t+U2 (t) ) ]+ (r)
/3π) sin (3π/n>x[cos((C2-
3p)t+U2(t))cos((C2+3D)]+U
2 (t)) ] + (n15π) sin (5π/
n) x[cos((C25D)t+U2(j))-c
os[(Ω +5p)]+U2 (t))]] +・・・・・・
]+ (I□o/n) [sin (Ω t+U, (t
)) 10(n/π) Sin(π/n>
s((Ω +p)t+U, (t))]] + (n/37r)Sin (37r/n>x[co
s((Ω,-3p)t+U,(t))-cos((Ω.

+3 p) t +U, (t) ) ]+ (n15
π) Sin (5π/n) x [cos((Ω.-5p
)t+U. (t))-cos((Ω.+5D)t+U,
(t)) ]+・・・・・・
] However, LJ-(1)=5-(t)+so,(t)(+=
1, 2. ..., n) Here, looking at equation (7), it can be seen that it is a combination of many carrier waves.

Adjacent wireless channel interference, which is a problem in system construction, is as follows:
It will be explained that the system according to the present invention can be operated without any problems in practical use by quantitatively evaluating same radio channel interference and transmission signal delay time gutter.

(I) Adjacent radio channel interference The number of time slots in one frame is 10. Taking as an example a case where the audio multiplicity is 10.1 and the frame period is 100 msec, we will quantitatively explain below that most signal components remain within one channel and have very little influence on adjacent channels. do.

In equation (7), adjacent radio channel interference will be greatest when all implementations are in use, that is, when all time slots are in use. Also, for convenience of calculation 1, the carrier wave frequency transmitted from each mobile radio*ioo is ΩH<r=1.2. ... "
1) and the transmitted signal UH (i = 1, 2.−
, n> nitsuiteΩ1=Ω2”””=Ωn U1=U2=-=U.

However, the influence on the amount of interference is ignored (actually, this is the maximum amount of interference that can occur). Equation (7) is expressed as follows.

1/ n= (I01/ r)) (sin (Ω1t
+U1 (j) ) + (n/7nSin (yr/
rl)X[C03((Ω,i) t+tJ1(t) )
−cos((Ω1+p)t+tJ1(t)) ]+(
n/3π) sin (3π/n) x [cos((C1
-3p) to 10u1(o)-CO3[(Ω1+3p
) j + LJl m ) ] + (n15π)si
n (5π/n>x[cos((C1-5p>i+
U1 (t))-cos((Ω1+5p)t+U1 (
t)) ] )+・・・・・・ As the value of p included in equation (9), set the frequency to 20π radians, that is, the frequency to 10H2, ignore the phase of the carrier wave, and set the energy (voltage) to the peak value. (As a result, the influence of interfering radio waves is greatly evaluated), it becomes as shown in the following formula.

I/n=(10/n>(1 ten(n/π) sin(π/n) +(n/3yr)s+n(37r/n) ten... )
(I□/n) ((n/π) sin (π/n)+ (n
/3π)sin (37r/n)+...) However, the position of the carrier frequency of the above interference radio wave from the perspective of other radio channels is ±p, ±, respectively, above and below the main carrier frequency. 2p, ±3p... Located far away. However, calculations continue based on the assumption that the area has the greatest impact.

So, sin (π/n), sin (3π/n),
Since the absolute value of sin (5π/n), . That is, if these are all set to 1, equation (10) becomes I/10=1+(n/π)(1+1/3+115+...
・+'l/ (2n-1)+...) +(n/π)(1+1/3 +115+...+1/ (2n-1>-t...) The right-hand side of this equation (11) The first term 1 refers to the main carrier component, the second item (n/π)() refers to the subcarrier component in the upper frequency band of the main carrier, and the third item (
n/π)() represents the subcarrier component in the lower frequency band.

When the energy distribution of a large number of carrier waves shown in equation (11) is shown on the frequency axis, it becomes as shown in FIG. From equation (11), the reserved subcarrier energy in the wireless channel (
i width value), energy within 10 Hz above and below the center frequency and energy within 10 to 20 KHz are compared. First, the energy (voltage value) within 10KH2 E = (IOKH2) is = P2/πX5.550
6 Also, the energy E (20
KH7) is =: 2/πX O, 1421 Therefore, R= E (20KH2) /E (IOKH2)'
= 0.0256, or approximately 1/40.

Similarly, if you find the energy within 20 to 30 KH2 above and below and compare it in the same way, it will be 0.00761 or about 1/1
It has gradually decreased to 30.

The above approximate example is a calculation result emphasizing the existence of a large number of subcarriers, but the transmission output is still 99%.
% or more of the energy exists within the transmission band of the own radio channel, and the remaining energy of 1% or less may cause radio wave interference to the remote channel.

Using equation (11), find the carrier wave power that can cause interference to the adjacent channel. However, in the calculations below, it is assumed that the frame configurations of adjacent channels are exactly the same.

The adjacent channels shown in Figure 5 have a channel spacing of 125K.
Hz apart, and if the components of the subcarrier frequency 75KH2 to 175Kllz cause interference within this channel, the total power is calculated from equation (11).On the other hand, the energy of the main carrier (this is the main carrier of the adjacent channel) Since the signal to jamming ratio (equal to the energy of
(hereinafter abbreviated as D/U) is 1/0.0027, which is 50 dB when expressed in decibels (however, it is a power ratio).

In the above calculation, p was 20π radians (10H2), but a similar calculation is performed when p is 100Hz (the purpose of increasing p is to shorten the signal delay time as mentioned above). , the signal-to-interference ratio is 30 dB (
Ii power ratio. By the way, in general mobile communications, the allowable D/U (signal wave to interference wave) value as co-channel interference is 24 dB (power ratio), so the above calculated value is satisfied with a sufficient margin. It shows that there is. In other words, it can be seen that even if the transmission wave according to the present invention is operated intermittently in a pulsed manner, the radio wave interference exerted on adjacent channels can be ignored.

The above explanation was based on the mobile radio device 100, but
Similarly, calculations can be made for transmissions from the wireless base station 30, and the results are almost the same. However, the wireless base station 30
In the case of transmission from , the usage conditions within the time slot for synchronization signals and control signals differ, and the usage frequency distribution within the time slot differs by this amount, but the effect is small.

(n) Co-channel interference Co-channel interference occurs due to the characteristics of the bandpass filter or intermittent circuit set at the output section of the wireless transmitter circuit, which is due to the higher order of the transmitted pulse expressed by equation (9). wave,
This is because a carrier wave having a carrier frequency with a large value of n out of Ω1±np is not output. In this case, the ideal shape of the envelope of the signal wave sent out into space is not a rectangle (within which the carrier wave is accommodated), but a waveform that is a rectangular wave with many sine waves superimposed on it. (The waveform will have a beat-shaped envelope as shown in Figure 2B ((j)).Then, signal components with this shape will enter other time slots, causing co-channel interference. cause.

This influence will be theoretically determined below.

Assume that time slots SD1 and SO2 are used for communication A and communication B (Fig. 2B (d)).The interference waves that communication A affects communication B can be expressed mathematically using equation (7) as below. It becomes like the expression.

xsin ((2m+1 > 7r/n) [c
os ((Q0(2m+1) p) t+U(t)
)-cost(Ω-(2m+1) p) to 10U(
t))] To specifically obtain Equation (16), it is sufficient to perform the same numerical calculation as already performed for Equation (1). Therefore, if the characteristic of the filtering circuit included in the wireless transmitting circuit 32 is set to a wide band, then mo is set to, for example, 10000 (1
0Kzx toooo=t00KHz> or more, the influence of co-channel interference can be ignored. In an actual circuit, this condition can be easily satisfied.

(nl) Influence of delay time of transmission signal The reason why a large transmission delay occurs at the transmitting/receiving end (transmitting/receiving terminal) is due to the following factors.

i) Divide the transmitted baseband signal into regular intervals and store them in a storage circuit (eg, BBD, C0D).

11) The signal received at the receiving end (receiving terminal) is divided into slots and stored in a memory circuit.

ii> In addition to the signal transmission time due to the distance between the transmitter and the receiver, the delay time caused by the IF circuit, the transmitter/receiver mixer circuit, the transmitter/receiver filter section, etc. is small and will therefore be omitted.

Of the above, 1ii) is, for example, in the above-mentioned car phone, the distance between transmitting and receiving is at most about 10 km (wired section is omitted), so 10KIn/300000Ks = 1/30 m5ec
In addition, for mobile phones, a system has been proposed in which the communication area of one wireless base station is made into a very small zone with a radius of approximately 25 meters (Ito, "Proposal of mobile phone system - An approach to ultimate communication -" Communication Society of Japan Technical Report C8 Study Group November 1986 C386-88 and "Mobile Telephone System Patent Application 1986-64023".

In the mobile phone system described above, the distance between transmission and reception is approximately 100 m at most (wired section is omitted), so 100 m/300000 = 1/3000 msec. Therefore, it can be ignored compared to i) and ii).

Now, the occurrence of the delay times I) and ii) is schematically shown in FIGS. 6A and 6B.

In FIG. 6A, the signal speed conversion circuit group 5 of the wireless base station 30
The input to the signal speed conversion circuit 51-1 in 1 is applied as shown in (a>), and (time flows from left to right) the signal speed conversion circuit 51-1 is applied to the king's room, which is the unit of speed (pitch) conversion. The signal A is compressed to T/n by the signal speed conversion circuit 51-1 and outputted so that the trailing edge of the compressed signal @A shown in (b) coincides with the trailing edge of the output shown in (b), which becomes (C). The mobile radio device 100 receives the compressed signal A at the timing shown in (d) at the input of the speed restoration circuit 138, and outputs the compressed signal A as shown in (a). The signal A shown is restored and output as shown in (e).Here, the delay time τ from the leading edge of signal A in (a) to the leading edge of signal A in (e)
1 is T-T/n. However, the transmission time from the transmitter output section to the spatial transmission section and the reception section output of the mobile radio device 100 was ignored.

In diagram M6B, the signal speed conversion circuit 51 of the wireless base station 3o
-1, the leading edge of the output signal A compressed to /n is output at the same time as the trailing edge ends. Therefore, the output of the wireless transmission circuit 32 is (
The mobile radio device 100 that has received this becomes as shown in C).
The input of the speed restoration circuit 138 becomes as shown in (d), and at the same time as the trailing edge of the compressed signal A, the leading edge of the signal A shown in (e), which has been expanded by n times and restored, is as shown in (d). Sent out. Therefore, from what is shown in (e), T+T/
A delay time τ2 delayed by n=τ2 occurs.

The circuit for processing the signal shown in FIG. 6A is
Although it is more complicated than that shown in Figure B, the delay time can be reduced. On the other hand, in the case of FIG. 6B, the delay time is slightly longer, but the circuit is simpler.

Now, in actual communication, especially in two-way communication such as voice communication, the sender expects a response from the other party, so the delay time needs to be twice τ or τ2. Try applying actual numbers. For example, if one time slot (one division) of a transmission signal is T = 1/10 seconds and time compression coefficient n = 10, then 2τ1 = 2x1/10 (1-1/10) = 18/1
00=0.18 seconds (180ms) 2τ2 =2X1/10 (1+1/10)=22/1
00=0.22 seconds (220 msec). On the other hand, the delay time for satellite communication is approximately 250m.
Since it is in seconds, the above value is about the same as in the case of satellite communication. If it is desired to reduce the delay time, it is sufficient to reduce the time slot (one time interval) in the baseband.

In other words, the number of kings is decreased from the above example, and T=1/100.
seconds, time compression factor n=100. Then, 2τ1=2X
1/100) (1-1/100)-2X99/1000
0 → 0.02 seconds (20ms) 2τ2 = 2x1/100) (1+1/100) = 20
2/10000 - 50.02 seconds (20 msec) As a concrete system, for example, the number of time slots allocated to the same mobile terminal within one frame is 10, and the time slots for other communications are cyclically allocated. The above conditions can be satisfied by giving . (The time for one frame should be reduced to 1/10).

The above is the amount of delay time that is inevitably determined by system design, and the delay time for wired systems has been omitted. However, the delay time of the wired system can be compensated for, so it does not have a major impact on the system.

The delay time that may affect the system will be explained below. This is because the distance between the mobile radio device 100 and the radio base station 30 varies depending on the location of each mobile radio device.
When the radio base station 30 receives communication signals transmitted (received) from each mobile radio, there is a possibility that gaps may occur due to differences in spatial transmission distances. .

For example, in the case of a car phone, if the mobile wireless device 100 is near the wireless base station 30 and another mobile wireless device is located at a distance of 107 from the wireless base station 30, the delay time difference is as described above <1/ It is 30m5ec. That is, since the time slot may double by about Q, 03 m5 ec, it is necessary to provide a protection time of about 0.05 m5 ec.

Further, in the case of a mobile phone, in the above example, the distance difference between the two mobile wireless wireless base stations and the wireless base station 30 is 100 m, so the delay time difference is 0. It becomes OO03msec.

Therefore, in this case, it can be ignored in a system having a signal component of 1 MH2 or less.

(IV) Calculation of frequency effective utilization rate The frequency effective utilization rate of the system is determined in the case of using the pulse communication according to the present invention explained above and in the case of using conventional FM communication. The modulated signal is assumed to be voice, and a telephone communication circuit is assumed. The following values are taken as the method specifications.

1) Pulse communication of the present invention 1 radio channel with 10 time slots or audio 1
0 channel can be transmitted. The required frequency bandwidth is 3Kl - 1z x 10 = 30KHz By providing a protection band, we can convert this into a sea urchin as shown in Figure 7A (a).
Set to 40KHz. This value is somewhat disadvantageous to the present invention, and in reality, such a wide guard band is unnecessary, but this value is used for comparison.

2) Conventional FM communication (1 audio channel/l!l transmission)
In this case, the baseband signal of one wireless channel is one audio channel, so the required frequency bandwidth is 3KHz x 1 = 3K
±8KH2 is required as a Hz protection band, and the radio carrier spacing is 12°5KHz (as shown in Figure 7A(b)).
In Japan, this standard is widely used in cordless telephones and the like in the 250M1-1z/400MH2 band.

), it can be seen that in order to simultaneously transmit 10 channels of audio signals, 12.5 KHz xiO = 125 KHz is required.

Comparing the above two systems, the ratio between the present invention and the conventional example is 80:125=0.64. In other words, in the pulse communication according to the present invention, SCPC (Si
channel per carrier)
It can be seen that a frequency band of only about 6g11 is sufficient compared to .

Furthermore, when the number of channels (number of simultaneous callers) increases, for example, when comparing 100 voice channels, the required frequency bandwidth for the pulse communication of the present invention is (3K to IZX1
00 +50 (guard band > KH7) X2 = 700KHz In conventional FM communication (SCPC), 1 2, 5Kf-1z x 100 = 1 25
Comparing the two 0KHz systems, the ratio is 700:1250=0.56, which further increases the superiority of the present invention.

Next, we will discuss TDM△(T), which has been actively researched in Europe recently.
ime DiViSin Haltil)le Acc
A comparison will be made between the frequency effective utilization rate when the ESS) is applied to mobile communication and the present invention.

3) For the DMS90 system (References: F,
Lindell et al.”Digital Ce1lula
r Radio for the 1990s tt
electronics P, 254-2
650Cj.

This system can multiplex 10 audio channels (1 channel is 16 bits/second) at a transmission rate of 340 bits/second, but the carrier spacing (required frequency bandwidth) is 300K)-1z. .

Therefore, the frequency utilization ratio of the present invention in 1) and the DMS 90 in 3) is 80:300=0.267. That is, the superiority of the present invention is more remarkable than that of the analog system (SCPC).

The above explanation is based on the case where all the signals used in the wireless channel are telephone signals, but if some or all of them are high-speed data or image signals, the carrier wave Since the modulation form is considered to be equivalent to that of a telephone signal, the results are as shown in FIGS. 7B (C) and (d) corresponding to FIGS. It can be seen that it is impossible to judge that it is equivalent to .

Effects of the Invention As is clear from the above explanation, by applying the present invention to a mobile communication system, it is possible to construct a system with higher frequency utilization efficiency than conventional systems.

In particular, it is possible to communicate with high-speed data other than telephone signals and wideband signals such as image signals using the same wireless channel as with telephone signals. There are some expensive ones.

In addition, in order to increase the effective use of normal frequencies, other design parameters such as adjacent channel interference, co-channel interference, and delay characteristics of transmission signals that affect line quality can be designed to values that can be effectively ignored. Orukara,
The effects of the present invention are extremely large.

[Brief explanation of the drawing]

Figure 1A is a conceptual block diagram showing the concept of the system of the present invention, Figure 1B is a circuit diagram of a mobile radio used in the system of the present invention, and Figure 1C is a wireless base used in the system of the present invention. FIG. 2A is a time slot structure diagram for explaining the time slots used in the system of the present invention; FIG. 2B is a waveform diagram showing the radio signal waveform of the time slot; FIG. 2C is a circuit diagram of the station; The figure is a time slot structure diagram corresponding to Figure 2A when transmitting a wideband signal, Figure 2D is a waveform diagram showing a radio signal waveform corresponding to Figure 2A when transmitting a wideband signal, Figures 3A and Fig. 3B is a spectral diagram showing the spectrum of a speech signal and a control signal, Fig. 3C is a spectral diagram corresponding to Fig. 3A (a) when transmitting a wideband signal, and Fig. 3D is a spectrum diagram when transmitting a wideband signal. FIG. 3B is a spectrum diagram corresponding to FIG. 3B, FIG. 3E is a circuit configuration diagram for multiplexing audio signals and data signals, FIGS. 4A and 4B are flowcharts showing the flow of operation of the system according to the present invention, and FIG. Figures 6A and 6B are spectrum diagrams for explaining radio wave interference to adjacent channels in this system, timing charts for explaining the delay time that occurs during signal compression and expansion in this system, and Figure 7A. 7B is a spectrum diagram for explaining the required bandwidth of this system and the conventional system, and FIG. 8 is a conceptual configuration diagram for explaining the conventional system. 0...Telephone network 20...Kanmon switchboard 2-1
~22-n...Communication signal O...Radio base station 1...Control/call signal processing section 2...Wireless transmitting circuit 35...Radio receiving circuit 8.
...Signal speed restoration circuit group 8-1 to 38-n...Transmission speed restoration circuit 9...Signal @
Selection circuit group 40...Control unit 1...Clock generator 42...Timing generation circuit 51...Signal speed conversion circuit group 51-1 to 51-n...Signal speed conversion circuit 52...
Signal assignment circuit group 52-1 to 52-n...Signal assignment circuit 91...Digital encoding circuit 92...Multiple conversion circuit 100.100-1 to 100-n...Mobile radio device 10
2...Terminal section 120...Reference crystal generator 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 1
34... Transmission section 135... Wireless receiving circuit 1
36... Reception mixer 137... Receiving section 138.
...Speed restoration circuit.

Claims (1)

[Scope of Claims] Each radio base means (30) each covers a plurality of zones and constitutes a service area, and each mobile base means (30) moves across the plurality of zones and communicates with the radio base means. A system in mobile communications using radio means (100) and barrier exchange means (20) for exchanging communications between said radio base means and said mobile radio means, wherein said radio base means transmits telephone signals. In order to transmit a signal having a bandwidth of m times an integer which may include 1 of the bandwidth of The speed of a signal with twice the bandwidth is n
a signal speed converting means (51) for converting the signal speed to a speed that is n/m times faster; a signal allocation means (52); and a wireless transmission means (3) for transmitting the output of the signal allocation means as radio waves.
2) and i times for an original signal with a bandwidth of i times, which is an integer that may include 1 of the bandwidth of a telephone signal, to transmit a converted signal n/i times faster.・Radio reception means (35) for receiving radio waves sent serially by each frame consisting of n time slots including slots; signal selection means (
39) and signal speed restoring means (38) for receiving each of the i-divided signals from the signal selection means and restoring them into continuous signals, the mobile radio means comprising: Radio receiving means (1
35, 121-1, 122-1), and a speed restoration for receiving the output of the radio receiving means and converting it to m/n times the speed to restore m divided signals into continuous signals. means (138) and a speed conversion for speed converting the speed of the signal to be transmitted having a bandwidth of i times the bandwidth of the telephone signal, which may be an integer including 1, to a speed n/i times faster; means (131); and wireless transmission for transmitting the n/i times faster converted signal as radio waves using i time slots out of n time slots in each frame. A time division communication system in mobile communication, comprising means (132, 122-2).