JPH02260928A - Radio base stations and mobile radios for time-division communication in mobile communications - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a radio base station and a mobile radio for time-division communication of a radio communication channel in 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 radio base station and a mobile radio device for time-division communication on the same radio channel, which 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.

U. Prior Art] In conventional mobile communications, for example, this has been adopted in the automobile system of Nchocho (Nippon Telegraph and Telephone Corporation), which is a commercial service. 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, each mobile radio device 15 is equipped with a function that allows selective use of one of a large number of radio channels (referred to as multi-channel access).

When communicating with the radio base station 13, the mobile radio 15 uses a control signal to contact the radio network control station 12 via the radio base station 73, which determines the use of the radio channels of the multiple radio base stations 13. The system is configured such that a communication channel number to be used for communication is determined according to instructions from there, and communication is performed 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, Since it is possible to allocate separate radio channels in response to these requests, it is possible to make a call. Unable to make a call (lost call) due to no 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, a single channel per φ carrier (
Single Channel per Carrie
r) SCPC, that is, a system in which one telephone (communication) signal is transmitted on each carrier wave, still has the above-mentioned unresolved problems.

[Means for solving the problem] A transmission signal (baseband signal) is divided into predetermined time intervals and stored in a memory circuit, and when read out, the data is read out at a predetermined speed n times faster than the speed at which it is stored in the memory circuit. It is built into mobile radios and radio base stations in order to transmit and receive data intermittently in time by reading the signal in a time slot and modulating the angle or field of view of a carrier wave with the signal accommodated by this time slot. , a wireless receiving circuit having receiving mixers facing each other and communicating with each other;
A switch circuit is provided for a wireless transmitting circuit having a transmitting mixer, a synthesizer applying voltage to the receiving mixer of the wireless receiving circuit, and a synthesizer applying voltage to the transmitting mixer of the wireless transmitting circuit, and intermittent the output of the synthesizer applied to each. The intermittent state is synchronized in both transmission and reception, and the same intermittent transmission and reception method as described above is synchronized with that of the mobile radio device for the wireless base station that communicates with the opposite side, and the reception side is accommodated in the predetermined time slot. In order to extract only the signals that are received, the wireless reception circuit is opened and closed to receive
By storing the demodulated 1q signal in a storage circuit and reading it out at a low speed that is 1/n of the speed at which it is stored in this storage circuit, the baseband signal that is the original signal that was transmitted can be reproduced. We have built a system that makes this possible.

Furthermore, the radio receiving circuits of the mobile radio and the radio base station are provided with circuits for removing pulse noise that occurs when switching time slots and the like.

As a result, even if all wireless channels given to the system are in use, new calls cannot be made if there are empty slots that are not used for communication within the time slots divided into time slots for each wireless channel. It is now possible to make calls using the mobile radio system, which has been a request, and it has become possible to realize a system that makes efficient use of frequencies.

[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 The system is divided into a plurality of time slot series, and a system has been constructed in which one of these time slot series can be selected and used for communication. 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. , one of the unused time slot sequences was given to enable communication with the radio base station.

In addition, by providing a circuit for eliminating pulse noise that occurs when switching time slots, etc., the communications of the plurality of sets can be prevented from interfering with each other, and can also prevent their own communications from being adversely affected. This made it possible to carry out communications without having to do so.

[Embodiment] FIG. 1A, FIG. 1B-1, FIG. 1B-2, 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 2o
It includes an interface with the mobile radio 11, 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 a wireless transmitting/receiving circuit that transmits and receives wireless signals.

Here, between the barrier switch 2o and the wireless base station 3o,
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-1 shows a circuit configuration of a mobile radio device 100 that communicates with a radio base station 3o. 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 communication signal that is the output thereof is sent to a speed recovery circuit 138.
is input to the control section 140 and clock 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 telephone section 101 and control section 140.

The communication signal output from the telephone unit 101 is divided into predetermined time intervals by a speed conversion circuit 131, and the speed (pitch in the case of an analog signal) is made high (compressed) and sent to a transmission mixer 133. The transmission signal is applied to the radio transmitting circuit 132 including the section 134 , and the transmission signal is sent out from the antenna section and received by the radio 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 device 100 includes a synthesizer 121.
-1 and 121-2, and selector switch 122-1.1
22-2, a transmission/reception intermittent controller 123 and a timing generator 142 that generate signals for switching the changeover switches 122-1 and 122-2, respectively.
The synthesizer 121-1, 121-2, the transmission/reception intermittent controller 123, and the timing generator 142 are controlled by the controller 140. Each synthesizer 121-1.1
21-2 is supplied with a reference frequency from a reference crystal oscillator 120.

FIG. 1B-2 shows the internal configuration of the radio receiving circuit 135. The received signal received by the antenna section is sent to switch 1.
The local oscillation frequency from the synthesizer 121-1 is applied to the receive mixer 136 via the synthesizer 22-1, and the output thereof is applied to the intermediate frequency amplifier 143.

The signal amplified by the intermediate frequency amplifier 143 is applied to the gate circuit 144 and the clock regenerator 141. This gate circuit 144 is for extracting only the signal of a desired time slot without interference from other time slots. The output of the gate circuit 144 is demodulated by the discriminator 145 and passed through the gate circuit 146 to the speed restoration circuit 1.
38. This gate circuit 146 removes transients from the demodulated waveform.

A wireless base station 30 is shown in FIG. 1C. N-channel communication signals 221 to 22-n with the gateway exchange 20
is connected to a signal processing section 31 which forms an interface through a transmission path. Now, the communication signals 22-1 to 22n sent from the barrier exchange 120 are input to the signal processing unit 31 of the wireless base station 30. The signal processing section 31 is equipped with an amplifier for compensating for transmission loss, and also performs so-called 2-wire to 4-wire conversion. That is, the input signal and the output signal are mixed and separated, and the input signal from the barrier switch 20 is
The signal is sent to the signal speed conversion circuit group 51. Further, the output signal from the signal speed restoration circuit group 3B is transmitted to the barrier exchange 120 by the signal processing section 31 using the same transmission path as the input signal. Among the above, input signals from the gateway exchange 20 are input to a signal speed conversion circuit group 51 including many signal speed conversion circuits 51-1 to 51-n, and 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.

The internal configuration of the radio receiving circuit 35 is also the same as that of the radio receiving circuit 135 of the mobile radio t1100 shown in FIG. 1B-2, and has the effect of removing pulse noise.

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, speech signals are separated corresponding to each speech channel CH1 to CHn. This output undergoes signal speed (pitch) restoration in a signal speed restoration circuit group 38 including signal speed restoration circuits 38-1 to 38-n provided for each channel, and then is input to the signal processing section 31. , after undergoing 4-wire to 2-wire conversion, this output is sent to the barrier exchange 1120 as a communication signal 22-1~
22-n.

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 storage circuit, and changing the speed when reading them out, for example, reading them out at a speed 15 times faster than when they were stored, 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, COD (Char
geCoupled Device), BBD
(Bucket BrigadeDeViCe > can be used, and the memory used in television receivers and tape recorders that compress or expand the time axis of conversations can be used (References: Koita ° et al.
“A tape recorder that compresses/expands the time axis of conversations”
Nikkei Electronics July 26, 1976 92-
133 pages).

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 by receiving a timing signal from a timing generator 42 that generates timing based on the clock and a control signal from the control unit 40.

The control or audio signals outputted from the barrier switch 20 via the signal processing unit 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. The signal allocation circuit group 52 is a buffer memory circuit that stores one section of high-speed signals output from the signal speed conversion circuit group 51, and receives timing information from the timing generation circuit 42 given by instructions from the control section 40. Then, the signal in the buffer memory is read out and transmitted to the wireless transmission circuit 32. When viewed in terms of channels, this timing information is chronologically arranged in series without overlapping, and when all control signals or communication signals described below are implemented, it appears as if it were a continuous signal wave. Become.

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. SDl and SD2 in Figure 2A (a)
．． -, SDn indicate 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 call signal as shown in the figure. If the call signal is not implemented, only the synchronization signal is added and the empty slot signal is added to the call signal portion. In this way, as shown in FIG. 2A(a), the wireless transmitter circuit 2
In this case, signals forming one frame are applied to the modulation circuit in time slots SD1 to SDn.

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, and as shown in the figure, the low frequency side (250Hz>) or the high frequency side (3850Hz>) can be used.This signal can be used, for example, when you want to send a control signal during a call. be done.

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 based on tone signals, it is possible to transmit many types of signals at high speed by increasing the number of tone signals or modulating the tone to create 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. 3C. FIG. 3C shows an audio signal digital encoding circuit 9.
This is an example of a case where the signal is digitized in step 1, the data signal is multiplexed with a data signal in a multiplex conversion circuit 92, and then applied to a modulation circuit included in the wireless transmission circuit 32.

Then, it is received by the opposite receiver, and the 3rd C
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 81100 is received by the antenna section of the radio base station 30, and is received by the radio receiving circuit 35.
is input to. FIG. 2A (b) schematically shows this upstream input signal.

That is, time slot 5tJ1. SU2. ...
SUn is a mobile radio 11100-1,100-2°...
, 100-n to the wireless base station 30 are shown. Also, each time slot 5L11. SU2...
, sun in detail.As shown in the lower left of No. 2A(b), they consist of a synchronization signal and a control signal or a call signal. However, the wireless base station 30 and the mobile wireless t
1100, or depending on the signal speed, it is possible to omit the synchronization signal. 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 unit 40 after the call signal has been subjected to similar processing. Further, the call signal is applied to the 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 SU5urf. The signal or speech signal is separated and output. Each of these signals is
The signal is input to the signal speed restoration circuit group 38. This circuit has the function of performing inverse conversion of the speed conversion circuit 131 (Fig. 1B-1) in the mobile drone 100 on the transmitting side, thereby faithfully reproducing the original signal and transmitting it to the gateway exchange 20. will be done.

The mode of transmission in a 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 magnitude 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 after performing the same processing as the call signal.

Next, as shown in FIG. 1B-1, the mobile radio 11100 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, audio signal (0.3KH2~3.0KHz
3B shows the frequency distribution on the output side when the signal speed conversion circuit group 51 (FIG. 1C) passes through the signal speed conversion circuit group 51 (FIG. 1C). In other words, if the audio signal is converted 15 times as described above, the frequency distribution of the signal is as shown in Figure 3B < 4
．． This means that it has been expanded to 5KHz to 45KH2.

The figure shows a case where the control signals are simultaneously transmitted using the lower frequency band of the audio signal. Among these signals, control signals (0.2 to 4.0KH2) and telephone calls @
Assume that CH1 (represented as sDl in 4,5 to 45 KH2) is accommodated in a time slot, for example SDl. The same applies to the audio signals accommodated in the other time slots SD2 to SDn.

That is, time slot soi <i=2゜3, -
, n) accommodates a control unit @ (0,2 to 4.0KH2) and a communication signal CHi (4,5 to 45KH2). 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 call 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±45 KHz. 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
, 8. If fH is the maximum signal speed due to the above-mentioned speed increase of the audio signal, the following inequality must hold between the two.

f > 2fH ep On the other hand, in the case of digital signals, audio is usually digitized at a speed of about 64 kb/s, so we have explained the case of analog signals.・It is necessary to read the scale on the horizontal axis in Figure 3B by raising it by about one digit. However, 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 a 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 1120.

Next, the call originating/receiving operation of the system according to the present invention will be explained by taking the case of a voice signal as an example.

(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
The radio receiving circuit 135 in FIGS. B-1 and 1B-2 starts capturing the control signal included in the downlink (radio base station 30→mobile radio device 100) radio channel (channel CH71). If the system is provided with more than one radio channel, i) the radio channel exhibiting the highest received input electric field, i) the radio channel dictated by the control signal contained in the radio channel, and iii) the radio channel within the radio channel. A radio channel (hereinafter referred to as channel CH1), such as a channel with an empty time slot among the time slots, enters the receiving state according to the procedure determined by the respective system. 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 so as 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 telephone receiver 101 goes off-hook (starts making a call) (3201, FIG. 4A), the synthesizer 121-2 in FIG. A control signal to be generated is received from the control unit 140.

Further, the switch 122-2 is also turned toward the synthesizer 121-2 side and becomes fixed. Next, wireless channel CH1
The call control signal outputted from the telephone unit 101 is sent using the telephone unit 101. 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 time slot Sun, and is sent in bursts, and no signal is transmitted during other time slots, so it does not adversely affect other communications. 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 signal will be sent after one frame or even in the next frame. Sent using time 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 wireless base station 3o includes a synchronization signal and a subsequent control signal, and by receiving this, the pre-move LA device 100 converts the frame. Synchronization becomes possible. Roughly speaking, 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 sor <r=1.2°...
, n) may contain only synchronization and speech signals when they are being used by other communications; By receiving this control signal, the mobile radio device 100 can know which time slot should be used to send out the calling signal.

Note that if the im slot is in use all evenings, 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 Sun for uplink signals is an empty slot, it is decided to use this empty time slot, and the necessary timing is determined from the response signal from the radio base station 30 by sending out a control signal for calling. burst-like control signals can be sent out.

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 further reduced, the following method may be used. If the mobile radio device 100 finds an empty time slot in which it can make a call, it does not use the entire time slot, but rather uses only the first half of the time slot for some mobile radio devices and only the second half for other mobile radio devices. This is a method that allows you to use 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 call 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 (3202). Search for time slots. The time slot given to mobile radio 1100 may be Sun, but a search is performed just to be sure. It is mobile radio 1
In addition to 00, this is also used to respond to simultaneous calls from other mobile radios, and to provide time slots suitable for service types and service classifications.

As a result, if the time slot SD1 is empty, for example, the time slot SDn of the radio channel CH1 is used for the mobile radio device 100, and the time slot uplink (mobile radio device 100→radio base Station 30) SUL.

and instructs to use the corresponding downlink (radio base station 30 → mobile radio device 100) SDI (3203
>. In response, the mobile radio 1100 transitions to a state in which it can receive data in the instructed time slot SD1, and at the same time, the mobile radio 1100 shifts to a state in which it can receive data in the designated time slot SD1, and at the same time, the mobile radio 1100 shifts to a state in which it can receive data in the designated time slot SD1, and at the same time, the mobile radio 1100 shifts to a state in which it can receive data in the designated time slot SD1, and also changes the time slot SU1 (second A
(see figure (b)). At this time, the mobile radio device 100
The control unit 140 operates the transmission/reception intermittent controller 123 and starts operating the switches 122-1 and 122-2 (3204>. At the same time, a slot switching completion report is sent to the radio base station using the uplink time slot SU1. 30 (5205) and waits for a dial tone (5206).

Time slot 5t of the radio carrier wave of this uplink radio signal
The state of J1 is schematically shown in FIG. 2B (C). In addition to the time slot SU1, the radio base station 30 also receives SU as an uplink signal from another mobile radio device 100.
3 and Sun are included in one frame and sent.

The radio base station 30 that has received the slot switching completion report (
3207>, sends a calling signal to the gateway exchange 20 8208>, upon receiving this, the gateway exchange 20 detects the ID of the mobile radio 100 and selects the necessary switch from among the switch group included in the barrier exchange 20. Turn on (320
9), send a dial tone (3210, 4th B)
figure).

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 (S212).

When transitioning to this state, the telephone unit 1 of the mobile radio device 100
Since a dial tone is heard from the 01 handset, the dial signal begins to be sent. This dial signal is speed-converted by the speed conversion circuit 131 and sent out from the wireless transmission circuit 132 including the transmission section 134 and the transmission mixer 133 using the uplink time slot SU1 (3213>. Thus, the transmitted dial signal is The signal is received by the radio receiving circuit 35 of the base station 30.The radio base station 30 already responds to the calling signal from the mobile radio 100, gives the time slot to be used, and selects the signal of the radio base 830. Circuit group 39 and signal assignment circuit group 52
, the uplink time slot SU1 is received, and the signal of the downlink time slot SD1 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 passes through the signal speed restoration circuit group 38.
Here, the original transmission signal is restored and transferred to the gateway exchange 20 as a call signal 22-1 via the signal processing unit 31 (3214), and a call 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 call signal) undergoes speed conversion at the signal speed conversion circuit group 51 in the wireless base station 30, and is then given a time slot SD1 by the signal allocation circuit 52-1 of the signal allocation circuit group 52. ing. 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 telephone receiver of the telephone/packing machine section 101. Thus, a call is started between the mobile radio device 100 and a regular telephone within the regular telephone network 10 (S216>).

The call is terminated by on-hooking the handset of the telephone unit 101 of the mobile radio R100 (S217>, the end-of-call signal and the on-hook signal from the control unit 140 are transmitted to the speed conversion circuit 1.
31 from the wireless transmission circuit 132 to the wireless base 830 (S218), and the control unit 140 stops the operation of the transmission/reception intermittent controller 123, and switches 122-1 and 122-2 to the synthesizer 121, respectively. -1 and 121-2 output ends.

On the other hand, in the control unit 40 of the radio base station 30, the mobile radio device 1
When a call termination signal is received from 00, the call termination signal is forwarded to the barrier switch 20 (5219), and a switch group (not shown)
The switch is turned off to end the call (3220>. 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 are exchanged between the radio base station 30 and the mobile radio device 100 through the signal rate conversion circuit 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 problem even through the signal speed conversion circuit group 51, signal speed restoration circuit group 38, control signal speed conversion circuit 48, or signal processing section 31, as with audio signals. .

(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 waiting state to receive a downlink control signal of the radio channel CH1 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 unit 40 (FIG. 1C) via the signal rate conversion circuit group 51 and the signal allocation circuit group 52, similarly to the voice signals. Then, the control unit 40 uses an empty slot among the downlink time slots of the radio channel CH1 addressed to the mobile radio device 100, for example, using SDI, to determine the ID of the mobile radio device 100.
Signal 10 Incoming call signal display Signal 10 Time slot usage signal (
The mobile radio device 100 uses, for example, SUl corresponding to SDl).

In the mobile radio t1100 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 1.
To confirm that it is an incoming call signal to 00, telephone section 1
At the same time, the switch 122 operates the transmission/reception intermittent controller 123 to stand by at the designated time slots SD1 and SU1.
-1°122-2 starts turning on and off. In this way, the state has shifted to a state in which calls can be made.

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,
Let us take an example of an uplink radio signal (transmitted by the mobile radio device 100 and received by the radio base station 30).

First, assume that all uplink radio signals are empty lines, that is, all time slots are not used. The mobile radio device 100 that wishes to make a call receives a control signal in the downlink radio channel, for example, time slot SD1, so that the mobile radio device 100 determines the usable time slot of the uplink radio channel.
Once a slot (for example, time slot SDI'') has been selected, a control signal (a call signal if a call 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 conversation 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 audio signal (for signals in analog or digital format) that is the output signal (or control signal) of the telephone unit 101 in FIG. 1B can be expressed as follows.

μ (1) = i box aHcO3 (Machi 1 + & Kasumi (・1) Also, the control signal that exists outside the band is μ. (1) =, Hebo H cos (ω, 1 + θ Kasumi) Here, a
i is the magnitude of the amplitude, ω: is the angular frequency of the signal, ai is 1=
Represents the phase when it is 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=I□ Sln f (ω10μ(t)) dt is expressed by the following equation.

=Iosin (ωt+5(t)> (3) or 1=IQSinf(ω10μ(1)10μ.(t)>dt=
I□5in(ωt+5(t) +5o(t) >However, m・=a1/ωi (i=1.2.3...n)(4
5(t)+5C(t) shown by the equation ) represents a transmission signal in the form of -Funetsuri.

Now, using equation (3) or equation (4), radio signal 1 sent from the antenna of mobile radio device 100 = <101
/n> [1+2i1(n/m7r) )XSin
(m7r/n) CO3mp t ]xsin (Ω
1 i+s1 (t) + 5o1(t) ) but n
is the number of slots (equally spaced) in one frame, p
is the switching angular frequency, and m is a positive odd number.

Equation (5) is the mobile radio device 10 using the same radio channel.
In this case, the transmission signal from 0 is in one of n slots in one frame, but in a state where all slots are implemented with signals, that is, n mobile radio devices 100 use the same radio channel. The mathematical expression of the signals included in the wireless channel when the wireless channel is in communication is as follows.

I= (I01/n> [1+221-, (n/m7
r) )XSin (m7r/n″)cosmptkoxsin (Ω1t+51(t)+5o1(t))+
(I02/n) [1+2 Fl(n/mπ) )XS
in (mπ/n) xcos mp (t-2'yc/ (np)) ]
xsin (Ω2 i + S 2 (j) + S
c2(1)) xsin (mπ/n) xcos mp (t-4yr/ (rl>)]
xsin (Ω3t + S3 (t) + 5c3(
t) )+・・・・・・ +(Ion/n) [1+2Σ (n/mπ)] m=1 xsin (mπ/n) xcos mp (t-2(n-1) yr, / (n
p) ) )xsin (Qnt+s, (t) +s,
o(t)) 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 Ω1. Ω2. ..., Ω. is each mobile radio 11100
Different symbols were used because the carrier frequencies transmitted by the two stations are slightly different even though they are on the same radio channel. S
・(1) and S. The same applies to 1(1) (+-1, 2°..., n).

The radio signal transmitted from the radio base IQ30 in FIG. 1A is expressed by equation (6), and the mobile radio device 100 communicating with Timing generator 14 whose only signal is shown in FIG. 1B-1
2 and transmission/reception intermittent controller] 23 for selective reception. Now, if this is the time slot Sol shown in FIG. 2A for the mobile radio device 100-1, (6
This is the first term on the right-hand side of equation ), that is, the signal shown on the right-hand side. When the equation (5) passes through the amplitude limiter included in the receiving section 137 in FIG. 1B-1, it takes the form shown in the equation below.

J=Asin (Ω, t+s, (t) +5C1(
t) >(5') However, A is the amplitude and is not related to frequency or time.

When equation (5') passes through the frequency discriminator included in the receiving section 137, the following demodulated output is obtained: e(t)=μ(1)×μc(1). Then, by passing this output through the speed restoration circuit 131 shown in FIG. 1B-1, the original signal is reproduced.

The case where the wireless base station 30 transmits and the mobile wireless device 100 receives is explained above, but when the mobile wireless a100 transmits,
The case where the radio base 830 receives is also explained in the same way. However, in this case, instead of receiving only the signals required for the mobile radio device 100 itself as in the case of the mobile radio device 100, all the signals sent chronologically from a large number of mobile radio devices 100 are received. They are different in what they have to do.

Hereinafter, equation (6) will be modified as it will be necessary to investigate the influence of adjacent channel interference, which will be described later.

The right side of equation (6) is expanded as shown below.

I= (I01/n) [sin (Ω1 is 10u1m
)+(n/π) sin(π/n) x[5in((Ω1 +p) t+U1 (t) )+
5in((ΩIF))t+U1(↑))]ten(n/
3π) sin (37r/n) x [5in((Ω1 +
3 D) j +U1 (j)-(6π/n>(n-1
>) +5in((Ω -3p) j+L11 (t)+(6
π/n) (n-1H] + (n15π) sin (57r/n) x [5in
((Ω1+5 D) j + LJl ([)-(1
0π/n>(n-1>) +5in((Ω15p)i+U1 m +(10π/n>(n-1>)] +・・・・・・ ]+(I
02/n) [sin (Ω2 t+U2 (t)
)+(n/π)Sin(π/n>X[5in((Ω2 +p)j+LI2(t)]
]+in((Ω2-p)j+LI2(t))]
+ (n/3yr) sin (3π/n>X[5in
((Ω2 + 3 p) as 10tJ2 (t) - (6π
/n>(n-1)) +5in((Ω2 3p)t+U2 (t)+(6π/
n>(n-1>)] + (n15π) sin (5π/n) x [5in(
(Ω2 +5p)t+U2 (t)-(10π/n>(
n-1>) +5in((Ω2 5p)t+U2 (t)+(10π
/n> (n-1))] +......]
+(10n/n) [sin (Ω, t+Uo(
t) )+(n/π)sin(π/n) x[5in((Ω +p)t+U.(t))+5in(
(Ωn C)> t+un(t) ) ]+ (n/
3yr) sin (37r/n>x[5in((Ω,
+3p>↑+U, (t)-(6π/n> (n-1
>) 15in ((Ωn-3p)t+U, (t)-(6π/n
>(n-1))] + (n15π) sin (5yr/n>x[5in
((Ω, +5p)t+U, (t)-(10π/n)(n
-1>) +5in((Ω, -5p)t+Un(t)-(10π/
n>(n-1))] +......]
However, 明(t) =SH(t) +s. 1(t)(i=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 practical problems by quantitatively evaluating co-radio channel interference and the amount of delay time of transmission signals.

(I) Adjacent radio channel interference Taking as an example a case where the number of time slots in one frame is 10, the audio multiplicity is 10.1, and the frame period is 100 ms, most signal components are within one channel. The effect on adjacent channels is extremely small.
This will be explained quantitatively below.

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, the carrier wave frequency ΩH<r=1.2 transmitted from each mobile radio device 100. ..., n
) and the transmitted signal UH (Ω1=Ω2=...=Ω for i=1.2.−, n>.

Even if u1=U2=-=Un, the effect on the amount of interference is ignored (actually, this is the maximum amount of interference that can occur).

In addition, in the actual system, '01""■02="""= ■On= lo(8'
), so equation (7) can be expressed as follows.

I/n= (I□/n)(sin (Ω1t+U1(j
) ) + (n/π)Sin (7r/n)x[5i
n((Ω1+p>t+U1(1))+5in((Ω
-p)j+U1 (t))]+ (n/3yr)sin
(3π/n)x[5in((Ω1+3p)t
+ U 1 (t)-(6π/n>(n-1>) +5in((Ω1 3p)t+U1 (.

(6π/n) (n-1>)ko+ (n157r)Sin (57r/n)x[5i
n((Ω +5p)t+U1(t)−(10π/n>(
n-1>) +5in((Ω-5p>t+U1 (t)(10π
/n>(n-1>)]) +...] As the value of p included in equation (9), assuming 20π radians, that is, the frequency is 10Hz, and ignoring the carrier phase, the energy If (voltage) is expressed as a peak value (this will greatly evaluate the influence of this interfering radio wave), it will be as shown in the following formula.

1/n=(IO/n>(1 ten (n/π) Si mouth π/n) + (n/3yr) sin (37r/n)+-1-
(I□ /n) ((n/ π) sin (π/
n)+ (n/3π) sin (37r/rl)+・
・1 However, the position of the carrier frequency of the above interference radio wave from the perspective of other radio channels is p=0, that is, above and below the main carrier frequency, respectively, ±p, ±2p, ±3p,・
...It's in a remote place. 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 (5yr/n), . That is, if these are all set to 1, equation (10) becomes I/I□ =1+(n/π)(1+1/3+115+・
...+1/(2n-1) 10...) +(n/π) (1+1/3 175+...+1/ (2n-1)+...) The first right side of this equation (11) The first term refers to the main carrier component, the second term (n/π)() refers to the subcarrier component in the upper frequency band of the main carrier, and the third term (
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 (
Among the amplitude values), the energy within 10 KHz above and below the center frequency is compared with the energy within 10 to 20 KH2. First, the energy (voltage value) within l0KH2 E = (IOKH2) = 2n/πx 5.5
50 & Also, the energy E (2
0KHz) is = 2n/πx O, 1421 Therefore, R = E (20 to H2) /E (10KH2) 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 result of calculations emphasizing the existence of a large number of subcarriers, but despite this, 99% of the transmission output
% or more of the energy exists within the transmission band of its own wireless channel, and the remaining energy of 1% or less may cause radio wave interference to other channels.

Using equation (11), find the carrier wave power that causes 1q interference radio waves with respect to the adjacent channel. However, in the calculations below, it is assumed that the frame configurations of adjacent channels are exactly the same.

Adjacent channels shown in Figure 5 have a channel spacing of 125K.
llz apart, and if the components of the subcarrier frequency 75KH2 to 175KHz 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 (IOH7), but if we perform a similar calculation when p is 100Hz (the reason why p is increased is to shorten the signal delay time as described later), , the signal to jammer ratio is 30dB
(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. That is, 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 rarely applies to 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.

(II) Self-intra-channel interference Self-intra-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 a high-order transmission pulse expressed by equation (9). This is because a carrier wave having 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 has a beat-shaped envelope as shown in FIG. 2B (d)). Then,
Signal components of this shape will enter other time slots, causing self-intrachannel interference.

This influence will be theoretically determined below.

Assume that time slots SD1 and SD2 are used for communication A and communication B (FIG. 2B (d)). The interference waves that influence communication A on communication B can be expressed numerically with reference to equation (7) as shown in the following equation.

xsin ((2m+1 > 7r/n) [c
os ((Ω+(2m+1) p) t+U(t)
)−cos((Ω−(2m+1>Dot +U(t))) To specifically obtain equation (16), it is sufficient to perform the same numerical calculation as already performed for equation (1). Therefore, if the characteristics of the filtering circuit included in the wireless transmission circuit 32 are wideband, m□ is, for example, 10000 (1
0Kzx 10000=100 H7) If it is set to 0Kzx 10000=100 or more, the influence of self-channel interference can be ignored.

In an actual circuit, this condition can be easily satisfied.

(III) Co-channel interference Co-channel interference occurs when the present invention is applied to a small zone system. This occurs when radio waves from the channel are mixed in.

In FIG. 6, a small zone covered by each radio base station 30 is shown as a regular hexagon, and each radio base station 30 is arranged at the center of the hexagon. In this example, each of the radio base stations arranged at 1 to 7 uses a different radio channel, and the number of repetitions is 7.

In FIG. 6, the distance between two wireless base stations 30 using the same wireless channel (from the center of regular hexagon 1 to the other regular hexagon
When the shortest distance of the rectangle 1) is d, it is necessary to find the allowable value of D/U (the value of the ratio of the desired wave input level D to the interference wave input level U). To do this, the D/U value can be determined by knowing the frequency used in the system, the transmission power (size of the wireless zone), and the radio wave propagation state. In the conventional analog system, the interference value for the D/U value 1q is known, but
Since the modulation mechanism of the present invention is completely different, it is impossible to apply the conventional technology, and it cannot be accurately determined unless a system is actually constructed and measured. However, if conventional D/U allowable values are used, it is expected to be on the safe side.

(IV) Method for removing pulse noise during signal reception As already explained, the output signal when receiving the time division signal according to the present invention and multiplying the frequency (phase) discriminator output by 1q is as follows:
Although it is expressed by equation (5'), this is only an ideal case, and in practice, noise will occur due to various causes as explained below. These occur at the boundaries of each slot shown in FIG. 2A, and include a) those caused by discontinuity of different signals, b) rounding of the signal waveform due to the band characteristics of the intermediate frequency amplifier 143, and furthermore, transmission/reception. Things that are related to both include C) a difference between the timing of the signal speed conversion circuit group and the timing at the time of reception (including delay time when the signal is transmitted through space);

The radio reception circuit 135
A method for removing the inside will be explained in detail using FIG. 1B-2. FIG. 1B-2 shows the detailed configuration of the radio receiving circuit 135, in which the signal received from the antenna section is input to the receiving mixer 136, and its output is sent to the intermediate frequency amplifier 14.
3 amplifies it to an appropriate level.

A part of this output is input to the clock regenerator 141,
A clock is recovered, a portion of which is generated by the timing generator 14.
Added to 2. Further, a part of the output of the intermediate frequency amplifier 143 passes through the gate circuit 144, and then passes through the gate circuit 144.
phase) discriminator 145, and the signal is demodulated. This gate circuit 144 applies only the signals necessary for the mobile radio device 100 to the discriminator 145 according to the signal from the timing generator 142, and blocks unnecessary signals such as signals sent to other mobile radio devices. . As a result, generation of distortion noise such as intermodulation is eliminated.

Now, the output of the discriminator 145 is again applied to the gate circuit 146. This gate circuit 146 is for removing noise in the baseband band, and is mainly aimed at removing a) and C) of the above-mentioned noises.

Due to the action of this gate circuit 146, the speed restoration circuit 138
A good signal with significantly reduced noise will be added to the signal. Note that due to the action of this gate circuit 146, there is a possibility that a part of the desired signal may be blocked. To avoid this, move the signal mounting part in each slot shown in Figure 2A to the center of the slot, set a guard time at both ends of the slot, and avoid mounting the signal during this time. Bye. To achieve this, the signal rate conversion described above should be made a little faster, and when restoring the original signal after reception, the original signal should be restored at a correspondingly higher speed.

(V) 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).

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

ii) Signal transmission time due to the distance between the transmitter and the receiver, and the delay time caused by the IF circuit, the transmitter/receiver mixer circuit, the transmitter/receiver filter section, etc. are 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/m (wired section omitted), so 10Kttt/300000Ktn/sec = 1/
30 m5ec Also, 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 about 25 m (Ito "Proposal of mobile phone system - An approach to ultimate communication -゛IEICE Technical Report O8 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 100m at most (wired section omitted), so 100m/300000KIn/sec = 1/30
00 m5ec. 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. 7A and 7B.

In FIG. 7A, the signal speed conversion circuit group 5 of the radio base station 30
The input to the signal speed conversion circuit 51-1 in 1 is applied as shown in (a) (time flows from left to right), 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 signal A shown in (b). As shown in FIG.
is output from. Mobile radio m1oo received this,
The compressed signal QA is received at the input of the speed restoration circuit 138 at the timing shown in (d), and the signal A shown in (a) is restored and outputted as shown in (e). Here, the delay time τ1 from the leading edge of signal A in (a>) to the leading edge of signal A in (e) is T-T/n. The transmission time up to the receiver output was ignored.

In FIG. 7B, the signal speed conversion circuit 51 of the radio base station 30
In the input signal A shown in (a) to -1, the leading edge of the output signal @A compressed to T/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 restored signal A shown in (e) after being time-expanded by n times. is sent. Therefore, from the number shown in (e), T+T/
A delay time τ2 delayed by n=τ2 occurs.

The circuit for processing the signal shown in FIG. 7A 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. 7B, 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 τ1 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) = 18/100
=・0.18 seconds (180ms) 2τ2 =2xl/10 (1+1/10)=22/1
00=0.22 seconds (220 msec). On the other hand, the delay time in satellite communication is approximately 250m.
Since it is in seconds, the above value is about as long 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 coefficient n=100, then 2τ1=2X
1/100) (11/100) = 2x99/10000
→0.02 seconds (20ms) 2τ2 =2x1/100), (1+1/100)=2
02/10000 0902 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 time slots for other communications are cyclically given. If so, it becomes possible to satisfy the above conditions. (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, a mobile radio device 100 is located near the radio base station 30, and another mobile radio device is located near the radio base station 30.
Assuming that the distance is from 0 to 107, the delay time difference is <1/30 m5ec as described above. In other words, time
Since there is a possibility that the slot will be doubled by about 0.03 m5 ec, it is necessary to provide a protection time of about 0.05 m5 ec.

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

Therefore, in this case, it can be ignored in a system having signal components of IMH2 or less.

(vl) 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 3KHz x 10 = 30KHz. By providing a protection band, it is ±4 as shown in Figure 8 (a).
Set to 0KH2. 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) In the case of conventional FM communication (one audio channel/carrier wave), the baseband signal of one radio channel is one audio channel, so the required frequency bandwidth is 3KHz x 1 = 3K.
Hz ±8KH2 is required as a protection band, and the radio carrier spacing is 12°5KHz as shown in Figure 8(b).
(In Japan, this standard is widely used in cordless phones, etc. in the 250MHz/400MHz2 band.)
Therefore, it can be seen that in order to simultaneously transmit 10 channels of audio signals, 12.5 KHz xl 0 = 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 60% is sufficient compared to .

Furthermore, the number of channels (number of simultaneous callers) increases, and when compared with, for example, 100 voice channels, the required frequency bandwidth for the pulse communication of the present invention is (3KHz xlooo +50 (guard band) KHz) x2 = 700KHz. In FM communication (SCPC), 12.5 KHz xiOO=1250 KHz When two systems are compared, the ratio is 700:1250=0.56, which further increases the superiority of the present invention.

Next, let's look at TDMA (
Time Divisin Multiple 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 Ce1lular
Radio for the 1990s” Tel
communications P, 254-265.
0ct This system has 10 channels of audio at a transmission rate of 340 bits/second (1 channel is 16 bits per second, 7 seconds).
can be multiplexed, but the carrier interval (required frequency bandwidth) is 300KH2.

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).

[Effects of the Invention] As is clear from the above description, 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 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. Therefore, the effects of the present invention are extremely large.

[Brief explanation of drawings]

Figure 1A is a conceptual block diagram showing the concept of the system of the present invention, Figure 1B-1 is a circuit diagram of a mobile radio used in the system of the present invention, and Figure 1B-2 is the same as that of Figure 1B-1. FIG. 1C is a detailed circuit configuration diagram of a radio receiving circuit, FIG. 1C is a circuit diagram of a wireless base station used in the system of the present invention, and FIG. 2A is a diagram for explaining time slots used in the system of the present invention. Time slot structure diagram; Figure 2B is a waveform diagram showing the radio signal waveform of the time slot; Figures 3A and 3B are spectrum diagrams showing the spectrum of speech signals and control signals; Figure 3C is a voice signal and data FIG. 4A and FIG. 4B are flowcharts showing the flow of operation of the system according to the present invention; FIG. 5 is a spectrum diagram for explaining radio wave interference to adjacent channels in this system; FIG. 6 is a configuration diagram showing a small zone configuration to which the present invention is applied; FIGS. 7A and 7B are timing charts for explaining the delay time that occurs during signal compression/expansion in this system; The figure is a spectrum diagram for explaining the required bandwidth of this system and the conventional system, and FIG. 9 is a conceptual configuration diagram for explaining the conventional system. 10... Telephone network 20... Gateway switchboard 22
-1 to 22-n...Communication signal 30...Radio base station 31...Control/call signal processing section 32...Wireless transmitting circuit 35...Radio receiving circuit 3
8... Signal speed restoration circuit group 38-1 to 38-n... Transmission speed restoration circuit 39...
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 91...Digital encoding circuit 92...Multiple conversion circuit 100.100-1 to 100-n-...M110 before movement
1...Telephone unit 120...Reference crystal generator 121-1, 121-2 River synthesizer 122-1, 1
22-2...Switch 123...Transmission/reception intermittent controller 131...Speed conversion circuit 132...Wireless transmission circuit 133...Transmission mixer 1
34... Transmission section 135... Radio receiving circuit 1
36... Reception mixer 137... Receiving section 138.
... Speed restoration circuit 141 ... Clock regenerator 142 ... Timing generator 143 ... Intermediate frequency amplifier 144 ... Gate circuit 145 ... Discriminator 146 ... Gate circuit.

Claims (1)

[Claims] 1. Each radio base means (30) each covering a plurality of zones to constitute a service area, and a radio base means (30) for moving across the plurality of zones and communicating with the radio base means. A system in mobile communications using each mobile 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: A signal speed conversion means (51) for converting the speed of a plurality of divided signals into high speeds, and a means for serially outputting the plurality of divided signals in time series at timings assigned to the plurality of divided signals converted to high speed. a signal allocation means (52); a wireless transmission means (32) for transmitting the output of the signal allocation means as radio waves; a radio receiving means (35) having a gate means for gating a predetermined portion of the divided signal in order to remove pulse noise for receiving radio waves serially sent to the radio wave; signal selection means (39) for receiving the output of the wireless reception means, converting the plurality of divided signals sent serially into parallel signals and outputting each signal; and each signal selection means from the signal selection means. A radio base station for time division communication in mobile communication, comprising a signal speed restoration means (38) for receiving a signal, converting it to a low speed, and restoring the signal. 2. Each radio base means (30) each covering a plurality of zones to constitute a service area, and each mobile radio means (30) for moving across said plurality of zones and communicating with said radio base means ( 100) and barrier exchange means (20) for exchanging communications between the radio base means and the mobile radio means, wherein the mobile radio means is configured to communicate from the radio base means to the mobile radio means. radio receiving means (135, 122- 1, 12
3), a speed restoring means (138) for receiving the output of the radio receiving means, converting it to a low speed and restoring the segmented signal into a continuous signal, and transmitting the signal to be transmitted every predetermined time unit. speed converting means (131) for converting the speed into high speed by dividing the speed into two speeds; and wireless transmitting means (132, 122-) for transmitting the output of the speed converting means as radio waves at a predetermined timing.
2,123); A mobile radio device for time division communication in mobile communication, comprising: