JPH02260929A - Time slot allocation method in radio channel of time division communication system in mobile object communication - Google Patents

Abstract

PURPOSE:To enable the plural groups of communication to execute communication without mutually giving the disturbance by hourly dividing one radio channel into plural time slot systems and giving one of the time slot systems of the radio channel during using when the other mobile radio set executes transmission while one mobile radio set communicates with a radio base station. CONSTITUTION:Control information of a time slot which is used at present and an unused time slot are included in a control signal transmitted from the radio base station 30. It can be recognized which time slot the mobile radio set 100 has to use so as to transmit a call signal by receiving the control signal. The mobile station 100 uses the idle time slot, transmits a call control signal, takes out a necessary timing from a response signal from the radio base station 30, and transmits the burst control signal.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a method for allocating time slots within a radio channel in a time division communication system in mobile communication. More specifically, given a radio channel, it is used to communicate with one of a number of mobile radios within a service area.
If another mobile radio device requests communication using the same radio channel while the other mobile radio device is communicating with the opposing radio base station by setting up a radio channel, the radio The same radio channel allows an independent radio link to be set up between another mobile radio device and the radio base station using the same radio channel without adversely affecting communication with the base station. The present invention relates to a method for allocating time slots within a radio channel without being affected by co-radio channel interference or adjacent radio channel interference for time-division communication systems.

[Prior Art] In conventional mobile communications, it has been adopted, for example, in the automobile system of NTT (Nippon Telegraph and Telephone Corporation), which provides commercial services.This will be explained with reference to Fig. 10. A plurality of radio channels are assigned to the station 13 in order to simultaneously communicate with a plurality of mobile radios 15 installed in a large number of automobiles in a zone 14, which is its service area.On the other hand, Each mobile radio 1115
is equipped with a function that allows selective use of one of a number of wireless channels (referred to as multi-channel access). When communicating with the radio base station 13, the mobile radio device 15 uses a control signal to contact the radio network control station 12 via the radio base station 13, which determines the use of radio channels of a large number of radio base stations 13. , the system is configured to determine a communication channel number to be used for communication according to instructions from there, and 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 communication from a mobile radio of 10f1MI in the same service area Since it is possible to allocate separate radio channels in response to these requests, it is possible to make a call. Unable to make calls due to lack of channel (
The call was lost. The above was an example of using a wireless channel to transmit an analog signal, but even when audio is digitally modulated, single channel φbar or carrier (Single Channel per Car)
Even in the case of SCPC, that is, a system in which one telephone (communication) signal is transmitted on one carrier wave, the above-mentioned unresolved problems still exist.

[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. built in mobile radios and radio base stations for reading out in a time slot, angle-modulating or amplitude-modulating a carrier wave with a signal accommodated by the time slot, and transmitting and receiving the carrier wave intermittently in time; a wireless receiving circuit having receiving mixers facing each other and communicating;
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
The signal obtained by demodulation is stored in a storage circuit, and read out at a low speed of 1/n of the speed at which it is stored in this storage circuit, thereby reproducing the baseband signal that is the original signal that was transmitted. We have built a system that makes this possible.

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 a call to a desired mobile radio, and there is no interference such as co-channel interference or adjacent radio channel interference, making it 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. By providing one of the unused time slot sequences to enable communication with the wireless base station, the plurality of sets of communications can be performed without interfering with each other, and This makes it possible to actually communicate without having any adverse effects on one's own communications.

[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 circuit configuration of a mobile radio device 100 that communicates with a radio base station 30.

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 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 switches 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.
Synthesizers 121 - 1 and 121 - 2 , transmission/reception intermittent controller 123 , and timing generator 142 are controlled by control section 140 . Each synthesizer 121-1.1
A reference frequency is supplied to 21-2 from the 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 communications @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 unit 31 is equipped with an amplifier for compensating transmission loss, and
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 20 by the signal processing unit 31 using the same transmission path as the input signal.
sent to. Among the above input signals from the barrier switch 20, the input signals are input to a signal speed conversion circuit group 51 including multiple signal speed conversion circuits 51-1 to 51-n, and speed (pitch) conversion is performed 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 inputted to the signal speed restoration circuit group 38 via the signal selection circuit group 39, and the signal is speed (pitch) converted. and 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 3 -n 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 as a communication signal 22-1 to the barrier exchange 1fi20.
~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
geCoupted [)evice), B B
D (Bucket 8riQadeDeViCe
) can be used, 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
92-133).

The circuit using the COD/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.

Control or audio signals outputted from the barrier exchange 120 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 for 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 the control signals or call signals described later are fully implemented, they appear as if they were continuous signal waves. 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 in Figure 2A(a), 5D2
-, 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 transmitting circuit 32
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, you can use the low frequency side (250Hz>) or the high frequency side (3850H2).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 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. 3C. FIG. 3C 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 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 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 a mobile radio device 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 call 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 magnitude 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 performing similar processing on the call signal. 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 Sun. The signal or speech signal is separated and output. Each of these signals is 5,
The signal is input to the signal speed restoration circuit group 38. This circuit has the function of inversely converting the speed conversion circuit 131 (FIG. 1B) in the mobile radio device 100 on the transmitting side, and thereby the original signal is faithfully reproduced and the barrier exchange is 1 m! It will be sent to 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 speed conversion rate, it is also possible to perform the same processing as the call signal and then add the signal to the wireless transmission circuit 32 from the output of the signal allocation circuit group 52.

Next, as shown in FIG. 1B, the mobile radio device 100 also has a circuit configuration required when the radio base station 30 has one communication channel among its functions.

Original signal, for example, an audio signal (0.3KHz to 3.0KH2
) passes through the signal speed conversion circuit group 51 (FIG. 1C), the frequency distribution on the output side is as shown in FIG. 3B. In other words, if the audio signal is converted 15 times as described above, the frequency distribution of the signal will be < 4 as shown in Figure 3B.
．． This means that it has been expanded to 5KH2 to 45KH2.

The figure shows a case where the control signals are simultaneously transmitted using the lower frequency band of the audio signal. It is assumed that among these signals, a control signal (0.2 to 4.0 KH2') and a speech signal CH1 (4.5 to 45 KH2, expressed as SDl) are accommodated in a time slot, for example, SDI. The same applies to the audio signals accommodated in the other time slots SD2 to SDn.

That is, time slot sor <r=2゜3,・
, n> accommodate a control signal (0.2 to 4.0 KHz) and a communication signal CHi (4.5 to 45 KH2). 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 modulation section included in the above, the required transmission band requires at least fc±45KHz. However, fo is a 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 if 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 rep > 2 f H 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.

Furthermore, the control signal that has entered the radio base station 30 from the mobile radio device 100 is input to the radio reception circuit 35, but a part of its output is input to the control unit 4o, and the rest is sent to the three signal selection circuit groups. The signal is sent to the signal speed restoration circuit group 38 via. 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 1o and is transmitted via the signal processing section 31. It is sent to the barrier exchange 20.

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
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, the radio channel with the highest received input 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 CHI). 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 101 is off-hook (calling starts) (S201, FIG. 4A), the synthesizer 121-2 of FIG. 1B generates a local frequency that enables transmission of the wireless channel CH1. A control signal is received from the control section 140 to cause the control to occur.

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 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. The control signal transmitted from the radio base station 30 includes a synchronization signal and a subsequent control signal, as shown in FIG.
By receiving this, 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 SDi (i=1.2°...
・, n) is used by other communications,
In some cases, it only contains a synchronization signal and a call signal;
Even in such a case, the unused time slots usually contain a synchronization signal and a control signal, and by receiving these control signals, the mobile radio 100 determines which time slot to use to send the calling signal. It is possible to know whether to send the .

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.

FIGS. 2B (d) and (e) schematically show transmission waveforms from the wireless base 830.

First, (d) shows a case where the transmission signal from the wireless base station 30 is transmitted regardless of whether it is in a used time slot or an unused empty time slot.

However, in an empty time slot, the control information is 1
Rather than being sent over the entire duration of a time slot, it is sent at the beginning of the time slot, i.e. within the first short period of time, say 5% of a time slot, and the rest of the time is just idle. This shows that only the modulated carrier wave is being transmitted.

On the other hand, FIG. 2B (e) shows a case where the empty time slot includes only a carrier wave and no signal is transmitted. This is effective in preventing co-channel interference in the following systems. In other words, there are cases where no empty slot is displayed within any time slot, and in this case, the following audio multiplex signal S
D1. SD2. ..., searching for the presence or absence of SDn one after another,
I need to check for empty time slots.

Now, returning to the main topic, mobile radio 1100, which has received the control information sent from radio base 830 by one of the above methods, determines in which time slot it should send the call control signal, and You can make decisions including 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. It is also possible to send out burst-like control signals.

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, it is kept to a sufficiently small value. If call collisions are to be further reduced, the following method may be used. It is mobile radio If&100
If a mobile radio finds an empty time slot in which it can make a call, instead of using the entire time slot, some mobile radios use only the first half, and others only use the second half. . In other words, the portion of the time slot used as a calling signal is divided into several types, and this is used to classify a large number of mobile radios into groups, and each group is assigned a time period within that one time slot. It is a way of giving. Another method is to create many types of frequencies for control signals, group a large number of mobile radios, and give these 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. Above 2
The 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 the mobile radio t11c)O may be Sun, but a search is performed just to be sure. This is to accommodate simultaneous calls from other mobile radios in addition to the mobile radio 1100, and to provide time slots suitable for service types and service classifications.

As a result, for example, if the time slot SD1 is vacant, the mobile radio 1100 uses the time slot SDn of the radio channel CH1 to transmit the time slot uplink (from the mobile radio 100 to the radio base station 30) by the downlink control signal. SUl.

and instructs to use the corresponding downlink (radio base station 30→mobile radio I! 1100) SDl (S2
03>. In response, the mobile radio tJ100 transitions to a state in which it can receive data at the designated time slot SDI, and at the same time, the mobile radio tJ100 shifts to a state in which it can receive data at the designated time slot SDI, and at the same time, the mobile radio tJ100 shifts to a state in which it can receive data at the designated time slot SDI, and at the same time, the mobile radio tJ100 shifts to a state where it can receive data at the designated time slot SDI.
2A (b)). At this time, in the control unit 140 of the mobile radio device 100, the transmission/reception intermittent controller 1
23 to start operating the switches 122-1 and 1222 (3204>. At the same time, send a slot switching completion report to the radio base station 30 using uplink time slot SU1 5205>, and wait for a dial tone (3205>). 3206>.

Time slot SU of the radio carrier of this upstream radio signal
The state of No. 1 is schematically shown in FIG. 2B (C). In addition to the time slot SU1, the radio base station 30 receives an uplink signal SU3 from another mobile radio device 100.
and Sun are included in one frame and sent.

The radio base station 30 that has received the slot switching completion report (
S207>, the calling signal is sent to the gateway exchange 20 (3208), and upon receiving this, the gateway exchange 20 detects the ID of the mobile radio 100 and selects the necessary switch from the switch group included in the barrier exchange R20. Turn on (320
9>, send dial tone (3210, 4th B)
figure).

This dial tone is transferred by the wireless base station 30 (3211>, 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 transmitter 134 and the transmitter mixer 33 using the upstream time slot SU1 (3213>. Thus, the transmitted dial signal is The radio receiving circuit 35 of the base station 30 receives the signal.The radio base station 30 already responds to the calling signal from the mobile radio 100, gives the time slot to be used, and receives the signal from the radio base station 30. Selection 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 [100]
After passing through the three selection circuits-1, 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 (S214>, 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 1fi100.

The mobile radio device 100 is waiting for reception in the time slot SD1 of the radio channel CH1, and is received by the radio reception circuit 135, the output of which is sent to the speed recovery circuit 138.
is input. In this circuit, the original signal of the transmission is restored and input to the handset of the telephone 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 device 100 (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 station 30 (3218>), and the control unit 140 stops the operation of the transmission/reception/intermittent controller 123 and switches 122-1 and 122-2, respectively. It is fixed to the output ends of synthesizers 121-1 and 121-2.

On the other hand, in the control unit 40 of the radio base station 30, the mobile radio device 1
When the call termination signal is received from 00, the call termination signal is forwarded to the barrier switch 20. 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 PF 52 in the wireless base R30 are opened.

In the above explanation, control signals are exchanged between the radio base U30 and the mobile radio device 100 by the signal speed conversion circuit group 51. Although it was explained that the signal speed restoration circuit group 38 etc. are not passed through,
This is for convenience of explanation, and communication can be carried out without any problem even through the signal speed conversion circuit group 51, the signal speed restoration circuit u38, the control signal speed conversion circuit 48, or the signal processing section 31, as in the case of 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 1100, the mobile radio 1100 is in a waiting state to receive a downlink control signal of the radio channel CH1 in accordance with the procedure determined 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, SDI, to generate an ID signal of the mobile radio device 100, an incoming call signal display signal, and a time slot use signal. (For example, SUl corresponding to SDl is used for transmission from mobile radio device 100).

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 telephone unit 10 confirms that it is an incoming call signal to 0.
At the same time, the transmission/reception intermittent controller 123 is operated to stand by at the designated time slots SD1 and SU1, and the switch 122-
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 the 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 5D1) has been selected, a control signal (a call signal if a call path is set) is sent from the radio transmitter 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 output signal (or control signal) of the telephone section 101 of FIG. 1B, the data or voice signal (for signals in analog or digital format), can be expressed as follows.

Also, the control signal that exists outside the band is: where ai is the amplitude, ωi is the angular frequency of the signal,
θ1 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 the carrier wave is frequency modulated using equation (1) or equations (1) and (2), the modulated wave that is
□5in(ωt+5(t)> (3) or I= I□ sin f (ω10μ(1)10μ.(t)
>dt=Iosin(ωt+5(t) +5C(t)
＞However, 5C(t) = divination, sin (ω, 1θi)m
.=ai/ωi (i=1.2.3...n)■ 5(t)+5o(t) shown in equation (4) represents a transmission signal in the form of a negative boat.

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= (I01/n) [1+2i1(n/myr)
)xsin (myr/n)cos mpt]xsi
n (Ω j+81 (t) + S(:1(t) >
However, 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 R10 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+2E1(n/ml)x
sin (mπ/n)cosmp↑]xsin (Ω
1t+S1m +5C1(t))+ (I02/n)
[1+2':E1(n/mπ))xsin (mπ
/n) xcos mp (t-2yr/ (np))]xsi
n (Ω2j+52(1)+s,2(t))+(
103/n>N+2. Fl(n/mπ))xsin
(mπ/n) xcos mp (t-4yr/ (r+p)) ]
xsin (Ω3j×53(1)+5C3(t))”
(I on/n> [1+2 El('/mπ
)) xsin (mπ/n) xcos mp (t -2(n -1) yr/ (
np) ) ]xsin (Ω t+s (t) +
sC, (t) )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 Ω, Ω2. ..., Ω are different symbols because the carrier frequencies transmitted from each mobile radio device 100 are slightly different even though they are on the same radio channel. S.
(1) YaS. The same applies to 1(t) (+=1.2°..., n).

The radio signal transmitted from the radio base station 30 in FIG. 1A is
(6), the mobile radio device 100 that is communicating with each other transmits only the signals necessary for itself in the equation (6) to the timing generator 142 shown in FIG. 1B-1. Selective reception is performed using the transmission/reception intermittent controller 123. Now, if this is the time slot SD1 shown in FIG. 2A for the mobile radio device 100-1, the signal will be the first term on the right side of equation (6), that is, the signal shown on the right 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 following equation.

1=Asin (Ω1t+S1 (t) 15C1(
t) >(5') However, A is the amplitude and is not related to frequency or time.

When the equation (5') passes through the frequency discriminator included in the receiving section 137, the following demodulated output is obtained: e(t)=μ(1)×μo(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 described above, but when the mobile wireless device 100 transmits,
The case where the wireless base station 30 receives the signal will be explained in the same manner. However, in this case, instead of receiving only the signals required by the mobile radio device 100 itself as in the case of the mobile radio device 100, all the signals sent in chronological order from a large number of mobile radio devices 100 are received. They are different in what they must 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.

1= (I(>1/n)[sin (Ω, 10tJ, (
1))+(n/π) sin(π/n) x[5in((Ω1+ p > t + U 1 (t
) )+5in((Ω −p)↑10U1(t))]10(
n/3yr) sin (3π/n>x[5in((Ω1
+ 3 p) t +U 1 (t) - (6π/n) (
n-1)) +5in((Ω13p)t+L11 m+(6π/n>
(n-1>)] + (n15yr>sin (5π/n)x[5in
((Ω1 +5p)t+U1(t)-(10π/n)(
n-1>) +5inHΩ1 5p) 1:10LJ1 (j)+(1
0π/n>(n-1>)] +...Co+ (I02/n) [sin (Ω2 t+U2 (
t) )+(n/π) sin(π/n> x[5in((Ω2 + p) t +U2 (t)
)+S group ((Ω2-p) t+U2 (t) )
]+(n/3π) sin (3yr/n>x[5in(
(Ω2 + 3 p) t + U 2 (t) - (6
π/n>(n-1>) +s+n((Ω2 ap> j+U2 (i)+(6
π/n>(n-1>)koten(n15π) sin (5π/n> x[5in((Ω2 +5 p) t+U 2 (t)
-(10π/n>(n-1)) +5in((Ω2 5D) t+LI2 (j)+(1
0π/n>(n-1))] 10... ]+(1
0n/n) [s+n (Ωnt+tJ, (t)
) ten (n/π) sin (π/n> x [sin' ((Ω.+D) to ten U. (t))+5
in((Ω, -p) to 10 u, (t))] + (n/37
r) Sin (37r/n) x [5in((Ω, +
3 p ) t + U n (t)=(6π/n)(
n-1>) +5in((Ωn-3D)t+Un(t)(6π/n>
(n-1>)] + (n15π) sin (5π/n) x [5in ((Ω, + 5p), t + U n (t
)=(10π/n>(n-1>) 15in((Ωn 5 p) t +U n (t)
−(10π/n>(n-1>)] +・・・・・・]
However, Lli(1)=SH(t)+5oH(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 The number of time slots in one frame is 10. Taking as an example the case where the audio multiplicity is 10.1 and the frame period is 100 msec, it can be seen that most signal components remain within one channel and have very little influence on adjacent channels.
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 Ω transmitted from each mobile radio 1100, (r='+, 2...
・n) and the transmitted signal U・(i=1.2.・
..., n), Ω1=Ω2=...=Ω.

LJ1=u2=-=u.

However, 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=”””= 1On= lo(8'
), so equation (7) can be expressed as follows.

1/n= (I□ /n> (sin, (Ω1t+t
J1 m ) + (n/π) sin (π/n) x [5
in((Ω1+p)t+u1(o)+5in((Ω1
−p)↑+u1 (t) ) ]+ (n/3π)si
n (37r/n>x[5in((Ω1 +3 p)
j+U1 (j) (6π/n>(n-1>) +5in((Ω -3p)t+U1 (i)1(6π/
n>(n-1>)] + (n15yr>sin (57r/rl)x[5
in((Ω1+5p>t+U1(t)−(10π/n
)(n-1>) +5in((Ω-5p)t+U1(t)(10π/n
)Cn-1>)]) +......] As the value of p included in equation (9), the energy (voltage) is 20π radians, that is, the frequency is 10H7, and the phase of the carrier wave is ignored. If expressed as a peak value (this results in a greater evaluation of the influence of interfering radio waves), the following equation is obtained.

I/n= (I□/n>(1 + (n/π) sin(π/n> + (n/31sin (3π/n)−+−1(IO
/n) ((n/π)Sin (π/n>+ (n/3
π) sin (3π/n)+・) However, the position of the carrier frequency of the above interference radio wave from the perspective of other radio channels is p=o, that is, ±p, ±2p, above and below the main carrier frequency, respectively. ±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/I□ = 1 + (n/π) (1 + 1/3 + 115
+...+1/(2n-1) +...) +(n/π)(1+1/3 +115+...+1/ (2n-1)+...) 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 subcarrier energy (
Among the amplitude values), the energy within 10 KHz above and below the center frequency is compared with the energy within 10 to 20 KHz. First, the energy voltage value within 10KHz) E = (IOKH2) = 2n/πx 5.5
506 Also, the energy E (2
0Hz) is = 2n/πX O, 1421 Therefore R = E (20KHz) / E (10KHz) →
It can be seen that the value has gradually decreased to 0.0256, or approximately 1/40.

Similarly, if you find the energy within 20 to 30 KHz above and below and compare it in the same way, it is 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 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.

Assume that the adjacent channels shown in FIG. 5 are separated by H2 with a channel spacing of 125, and that components of subcarrier frequencies 75KH2 to 175KH2 cause interference within these channels, then the total power is calculated from equation (11). Since the energy of the main carrier wave (which is equal to the energy of the main carrier wave of the adjacent channel) is 1, the signal to interference ratio (hereinafter abbreviated as D/U) is 1/0.0027, expressed in decibels. It becomes 50dB (however, the power ratio).

In the above calculation, p was 20π radians (10H2), but if we perform a similar calculation when p is 100H2 (the purpose of increasing p is to shorten the signal delay time as described later), , the signal-to-interference ratio is 30 dB (
fi 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. 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 is negligible.

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) 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 the higher order of the transmitted 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 Figure 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) π/n) [:co
s ((Ω+ (2m+1) p)t+U(t)'
)-COS ((Ω-(2m+1) p)t+U(
t))] To specifically obtain Equation (16), it is sufficient to perform the same numerical calculations as already performed in the section (I) Adjacent Radio Channel Interference. Therefore, taking the characteristics of the filter circuit included in the wireless transmitting circuit 32 into a wide band, m□ is, for example, 1000 (100tlzx 1000=10
0 to H2) or higher, it becomes possible to ignore the influence of self-channel interference. 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 if the frequency used in the system, the transmission power (size of the wireless zone), and the radio wave propagation state are known. In conventional analog systems, the interference value is known for the D/LJ value obtained in this way, 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.

However, by using the method according to the invention, which is different from the above methods, it is possible to eliminate co-channel interference to a substantially negligible extent.

Now, let N be the number of wireless channels given to the system,
As shown in FIG. 2A, the signal is time-divided and frequency (phase) modulated to be transmitted onto the radio channel.

Here, the number of slots included in one frame is assumed to be n. Although n may be any number, it is easier to explain if it is a multiple of the number of repetitions, so n is set to 14. Also,
It goes without saying that the number of repetitions may be a value other than that shown in Figure 6, such as 12.19. In this case, two slots are allocated to each zone, and these slots are arranged in chronological order for each zone as shown in FIG. However, depending on the system, some control signals and unmodulated carrier waves may be output in empty time slots, as shown in Figure 2B (d>), but there are various restrictions to satisfy the no-interference condition. Therefore, in the following, the transmission waveform shown in FIG. 2B (e) will be used.

Now, in the case shown in Fig. 2B (e), the same radio channel is used in each sub-zone, but the slot used is the 7th slot.
As shown in the figure, since the time is different, small zones 1 to 7
It is clear that co-channel interference does not occur between the two. However, in the other zones, the illustrated zone 1 is scattered at various positions as shown in FIG. 6, but since these zones are far from each other, they usually do not cause any interference. However, the signals transmitted from each radio base station 30 need to be transmitted at the same time over all time slots.

As is clear from the above description, co-radio channel interference can be ignored by using the intra-radio channel time slot allocation method according to the present invention.

(IV) 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.

) The transmitted baseband signal is divided into regular intervals and stored 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.

iii) 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 aforementioned car phone, the distance between transmitting and receiving is approximately 10 touch at most (wired section is omitted).
Therefore, 10 excitation/300000/sec = 1/30 m5
ec 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 meters (Proposal of ItoP mobile phone system - An approach to ultimate communication) Institute of Electronics and Communication Engineers Technical Report O8
Study Group November 1986 C386-88 and "Mobile Telephone System" Patent Application 1986-64023).

In the above mobile phone system, the distance between transmission and reception is approximately 100m at most (wired section omitted), so 100m/300000KIII/sec = 1/3
000 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. 8A and 8B.

In FIG. 8A, 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 the speed (pitch) conversion unit is 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). The signal is output from the wireless transmission circuit 32 as shown. 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 restores the signal A shown in (a) as shown in (e). It is output to. 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 receiving section output of the mobile radio device 100 was ignored.

In FIG. 8B, the signal speed conversion circuit 51 of the wireless base station 30
In the input signal A shown in (a) to -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 to 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 input is expanded by n times and restored (the leading edge of the signal A shown in e>). 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. 8A 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. 8B, 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 = 1/1" 0 seconds time compression coefficient n = 10, then 2τ1 = 2X1/10 (1-1/10) = 18/10
0 = 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 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, T is decreased from the above example, and T=1/100
seconds, time compression coefficient n = 100, then 2τ1 = 2
x1/100) (1-1/100) = 2x99/100
00 → 0.02 seconds (20ms) 2τ2 = 2x1/100) (1+1/100) = 20
2/10000 Misaki 0.02 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. , it becomes possible to satisfy the above condition (it is sufficient to reduce the time of one frame 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 IJ 1100 and the radio base 7430 differs depending on the location of each mobile radio, so when the radio base station 30 receives the communication signal transmitted (received) from each mobile radio, the spatial transmission If each time slot is duplicated due to different distances, gaps may occur.

For example, in the case of a car phone, if a mobile radio 1fi100 is located near the radio base station 30 and another mobile radio is located at a distance of 10 KIn from the radio base station 30, the delay time difference is <1/30m5ec as described above. . 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 radios and the radio base station 30 is 100 m, so the delay time difference is O,OO03 msec.

Therefore, in this case, it can be ignored in a system having a signal component of 1 MH2 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, this can be adjusted by ±4 as shown in Figure 9(a).
Set to 0KHz. 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 wireless channel is one audio channel, so the required frequency bandwidth is 3KHz x 1 = 3K.
Hz ±8KHz is required as a protection band, and the radio carrier spacing is 12°5KHz as shown in Figure 9(b).
(250M in Japan) - This standard is widely used in cordless telephones and the like in the 1z/400MH2 band. ), it can be seen that in order to simultaneously transmit 10 channels of audio signals, 12.5 KHz x 10 = 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 .

As the number of channels (number of simultaneous callers) increases, for example, when comparing 100 voice channels, the required frequency bandwidth for pulse communication of the present invention is (3KHz xlooo + 50 (guard band) KH2) X2 = 700KHz In FM communication (SCPC), 1 2, 5KH2xl 00=1 250KHz2
Comparing the two systems, the ratio is 700:1250=0.56, which further increases the superiority of the present invention.

Next, we will discuss Ding DMA (
Time Divisin)faltiple Ac
A comparison will be made between the frequency effective utilization rate when applying cess) to mobile communication and the present invention.

3) For the DMS90 system (References: F,
Lindell et al.”[)digital Ce1lula
r Radio for the1990s”Te
communications = P, 254-2
650ct This system supports 10 channels of audio at a transmission rate of 340 bits/second (1 channel is 16 bits/second).
(seconds) can be multiplexed, but the carrier interval (required frequency bandwidth) is 300 KHz.

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 and co-channel interference that affect line quality, are discussed in the main text. In addition to being able to eliminate this by using the method described above, the delay characteristics of the transmission signal can also be designed to a value that can be effectively ignored, so 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 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. Figure 2A is a time slot structure diagram for explaining the time slots used in the system of the present invention; Figure 2B is a waveform diagram showing the radio signal waveform of the time slot; Figure 3A is a circuit diagram of the station; 3B and 3B are spectrum diagrams showing the spectrum of telephone calls and control signals, FIG. 3C is a circuit configuration diagram for multiplexing voice signals and data signals, and FIGS. Flowchart showing the flow of call operation, FIG. 5 is a spectrum diagram to explain 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, FIG. 7 is a time slot allocation diagram in this system, Figures 8A and 8B are timing charts for explaining the delay time that occurs during signal compression and expansion in this system, and Figure 9 is the present system and conventional system. FIG. 10 is a conceptual configuration diagram for explaining the conventional system. O...Telephone network 20...Kanmon switchboard 2-1
~22-n...Communication signal O...Radio base station 1...Control/call signal processing unit 2...Wireless transmitting circuit 35...Radio receiving circuit 8.
... Signal speed restoration circuit group 8-1 to 38-n ... Transmission speed restoration circuit 39 ... Signal selection circuit group 40 ... Control section 41 ... 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
1...Telephone unit 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... Radio receiving circuit 1
36... Reception mixer 137... Receiving section 138.
... Speed restoration circuit 141 ... Clock regenerator 142 ... Timing generator.

Claims (1)

[Scope of Claims] Each radio base means (30) each covers a plurality of zones and constitutes a service area, and each radio base means (30) moves across the plurality of zones and communicates with the radio base means. A system in mobile communication using mobile radio means (100) and barrier exchange means (20) for exchanging communications between the radio base means and the mobile radio means, wherein the radio base means comprises a plurality of a signal speed converting means (51) for converting the speed of each of the divided signals into a high speed, and a signal for serially outputting in time series at timings assigned to the plurality of divided signals converted to the high speed. an allocating means (52); a wireless transmitting means (32) for transmitting the output of the signal allocating means as radio waves; a radio receiving means (35) for receiving radio waves sent serially; It comprises a signal selection means (39) for outputting each signal, and a signal speed restoration means (38) for receiving each signal from the signal selection means, converting it to a low speed and restoring the signal, The mobile radio means includes radio reception means (135, 122) for receiving predetermined divided signals of the radio waves from the radio base means.
-1, 123), and a speed restoring means (138) for receiving the output of the radio receiving means (135, 122-1, 123) and restoring the divided signal into a continuous signal by converting it to a low speed. and speed converting means (131) for dividing the signal to be transmitted into predetermined time units and converting the speed at high speed; and for transmitting the output of the speed converting means (131) as radio waves at a predetermined timing. wireless transmission means (132
, 122-2, 123), allocating a large number of time slots included in each frame of the radio channel into a plurality of groups, and assigning each of these groups to each zone to which each of the radio base means belongs. The transmission timing of the same slot is substantially synchronized in all of the radio base means, and the use of the same time slot is permitted only in zones to which each of the radio base means belongs, which are geographically distant. A method for allocating time slots within a radio channel in a time division communication system in mobile communication, which eliminates the influence of co-channel interference by allocating time slots to the same radio channel.