JPH02283132A - Time division communication system in mobile communication - Google Patents

Abstract

PURPOSE:To attain the communication between a mobile radio equipment and a radio base station by supplying one of time slot series not in use in a radio channel already in use to the mobile radio equipment desiring for the communication newly. CONSTITUTION:A communication signal outputted from a telephone set section 101 is divided for a prescribed time interval by a speed conversion circuit 131, the speed is quickened and the resulting signal is fed to a radio transmission circuit 132 including a transmission mixer 133 and a transmission section 134, a transmission signal is sent from an antenna section by using one time slot and received by plural base stations. The mobile radio equipment 100 is provided with synthesizers 121-1-121-3 to make able to send and receive a signal of one channel, changeover switches 122-1, 122-2 and a transmission reception interruption controller 123 generating a signal to change over the switches 122-1, 122-2 respectively. The synthesizers 121-1-121-3, the controller 123 and a timing generator 142 are controlled by a control section 140.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a time division communication system for wireless communication channels in mobile communication. More specifically, given a radio channel, one of the many mobile radios in the service area is communicating with an opposing radio base station by setting up a radio link. 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, and the other mobile radio device The present invention relates to a time-division communication system using the same radio channel that makes it possible to set up an independent radio link between another mobile radio device and the radio base station using the same radio channel without being adversely affected by the radio base station.

[Prior Art] In conventional mobile communications, for example, it has been adopted in the automobile system of N-T (Nippon Telegraph and Telephone Corporation), which is in commercial service. This will be explained with reference to FIG. A certain wireless base 813 has its service area Zone 1.
A plurality of radio channels are allocated to simultaneously communicate with a plurality of mobile radio devices 15 mounted in each of the large number of automobiles in 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 wireless base station 13, the mobile wireless device 15
A control signal is sent to the radio network control station 12 via the radio base station 13 to determine the use of radio channels of a large number of radio base stations 13, and according to instructions from there, the call channel number to be used for communication is determined. The system is configured to communicate with subscribers of a telephone network 10 via an exchange 11 including switches SW.

[Problem to be Solved by the Invention] In this case, if the number of radio channels provided to a certain radio base station for calls is 10, the number of radio channels provided to a certain radio base station for calls is 10, It is possible to allocate different wireless channels to v1 for communication requests, so it is possible to make a call, but for a call request from the mobile wireless device that made the 11th request, Because there is no available wireless channel, calls cannot be made (calls are lost). The above was an example of using a wireless channel to transmit an analog signal, but even if audio is digitally modulated, a single channel per carrier
er) SCPCl, that is, a system in which one telephone (communication) signal is carried on each carrier wave and transmitted, still has the above-mentioned unresolved problems.

[Means for solving the problem 1 The 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
By storing the demodulated 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.

In addition, it is equipped with a means to detect radio wave interference.

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 to desired mobile radios, making it possible to realize a system that makes efficient use of frequencies.

[In effect: When there are a large number of mobile radios within a radio base station and its service area, 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 It is now possible to carry out communications without adversely affecting one's own communications.

Roughly speaking, if there is interference between the radio waves used between the mobile radio and other systems or other radio base stations within the own system during communication, this will be detected and the system will be able to prevent interference. wireless channel or other time slot without adversely affecting communications.

[Embodiment] FIG. 1A, FIG. 1B-1, FIG. 1B-2, and FIG. 1C show a system configuration for explaining an embodiment of the present invention. This system shown here uses a so-called small zone configuration, but there are references such as "Harmony Layer: Proposal of Mobile Telephone System - One Approach to Ultimate Communication", IEICE Technical Report C3a6-88, November 1988, etc. As shown in Figure 2, it is assumed that a so-called micro cell is used, in which the size difference of each zone is extremely small, within 1 inch.In this case, each wireless zone has a large overlap, and one wireless zone But it also serves as another wireless zone.

In FIG. 1A, 10 is a general telephone network, 11 is an exchange on the side of the telephone network 10, and 20 is a gateway exchange for connecting the exchange 11 and a wireless system. The gateway switch 20 controls a plurality of radio base stations 30 and many mobile radio devices in order to set up and release radio lines and perform channel switching in conjunction with zone migration. A communication control unit 21 that controls stations 30-1 and 30-2, an ID identification unit 24 that identifies the identification number of a mobile radio, and a transmission wave from a mobile radio to each radio base station 30-1. and 30-2, the S/N monitoring section 25 monitors the communication quality, and the connection between each radio base station 30-1 and 30-2 and the exchange 11 is controlled by the communication control section 21. A switch group 23 necessary for communication system switching is included.

However, since the switch group 23 in FIG. 1A is simple, only three lines are shown from one exchange, and the wireless base station 30-
Communication signal 22-1-1.22-1 to 1 and 30-2
-2 to 22-1-m and 22-2-1.22-2-2
The outgoing line for transmitting .about.22-2-m is a 2xm line.

The wireless base station 30 includes a group of communication path switches that interface with the gateway exchange 20, a communication path control unit that controls the communication path, an ID identification storage unit, a circuit that performs signal speed conversion, and time slot assignment and selection. It includes a circuit for transmitting and receiving multiple wireless channels, a control unit, and a device for transmitting and receiving multiple wireless channels.
In addition to setting and canceling wireless lines, many mobile radio devices1
It has a wireless transmitting/receiving circuit that transmits and receives wireless signals to and from 00.

Here, the barrier exchange is performed between the wireless base station 30 and the wireless base station 20.
There are transmission lines for transmitting communication signals 22-1 to 22-m including communication signals of communication channels CH1 to CI-1m and control signals.

In FIG. 1B-1, the wireless base station 30-1 or 30-
The circuit configuration of a mobile radio device 100 that communicates with the mobile radio device 100 is shown. Received signals such as control signals and call signals received by the antenna section enter a radio reception circuit 135 that includes a reception mixer 136 and a reception section 137, and the output communication signal is received by a speed recovery circuit 138 and a clock regenerator 141. It is input to the quality monitoring section 158. clock regenerator 1/41
Then, the clock is recovered from the received signal and transmitted to the speed restoration circuit 138, the control section 140, and the timing generator 1.
42 and the speed conversion circuit 131.

The speed restoration circuit 138 restores the speed (pitch in the case of an analog signal) of each compressed and separated communication signal in one time slot in the received signal of one channel to generate a continuous signal. obtained,
It is input to the telephone unit 101 and the control unit 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 a section 134, and the transmission signal is sent out from the antenna section using one time slot and received by the plurality of radio base stations 30.

A reception quality monitoring section 158 to which a portion of the output of the reception section 137 is applied monitors the reception quality (signal-to-noise ratio and presence or absence of interference) of the input signal. Roughly, an interference detector 162 is connected to the receiving end of the antenna in parallel with the input to the receiving mixer 136.
This is used to detect interference with one's own communication on the same channel and same time slot used for other communications, either in other systems or within the same system. This interference detector 162 monitors the presence or absence of interference during communication, and if it detects interference of a certain amount or more, reports it to the control unit 140.

In the timing generator 142, the transmission/reception intermittent controller 123. It supplies necessary timing to the speed conversion circuit 131 and speed restoration circuit 138.

This mobile radio 100 also includes synthesizers 121-1 and 1 to enable transmission and reception of one channel.
21-3, selector switches 122-1, 122-2,
A transmission/reception intermittent controller 123 that generates signals for switching the changeover switches 122-1 and 122-2 is included, and the synthesizers 121-1 and 121-3, the transmission/reception intermittent controller 123, and the timing generator 142 are , is controlled by the control unit 140. Each synthesizer 121 and 1 to 121-3 has a reference crystal excavator 1.
A reference frequency is supplied from 20.

With such a configuration, it is possible to communicate with the wireless base station 30 using one channel.

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.
221 to the receive mixer 136 to which the local oscillation frequency from the synthesizer 121-1 is applied;
Its output is applied to an intermediate frequency amplifier 143. The signal amplified by the intermediate frequency amplifier 143 is applied to the 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 Goo 1-circuit 146 removes transients from the demodulated waveform.

A wireless base 830 is shown in FIG. 1C.

m-channel communication signal 22- with the network PW exchange 20;
1 to 22-m are connected to a signal processing section 3'1 forming an interface through a transmission line.

Now, the communication signal 22- sent from the barrier switch 20
1 to 22-m 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 sent to the signal speed conversion circuit group 51.

Further, the output signal from the signal speed restoration circuit 138 is transmitted to the barrier exchange 20 as communication signals 22-1 to 22-m by the signal processing unit 31 using the same transmission path as the input signal.

Among the above, the input signal from the gate exchange) 120 is inputted to five signal speed conversion circuit groups including many signal speed conversion circuits 51-1 to 51-m, and is divided at predetermined time intervals to convert the speed (pitch). undergo transformation.

In addition, the signal transmitted from the radio base 830 to the barrier switch 20 is such that the output of the radio reception circuit 35 is
is input to the signal speed restoration circuit group 38 via the signal speed (
After being converted (pitch), it is input to the signal processing section 31 through a switch group 83.

Now, the control of the radio reception circuit 35 or the output of the communication signal is carried out by the communication @ selection circuit 39 which selects the signal for each time slot.
-1 to 39-m is input to the signal selection circuit group 39,
Here, speech signals are separated corresponding to each speech channel, CH1=CHm.

This output is a signal speed restoration circuit u3 including signal speed restoration circuits 38-1 to 38-m provided corresponding to each call signal.
8, after the signal speed (pitch) is restored, it is input to the signal processing unit 31, and after undergoing 4-wire to 2-wire conversion, this output is sent to the gateway exchange 20 as a communication signal @ 22-1 to 22- Sent as m.

The transmission quality monitoring section 34 has the functions of both the reception quality monitoring section 15B and the interference detection section 162 of the mobile radio device 100,
When deterioration in reception quality or interference is detected, the control unit 40
will be reported to.

Furthermore, the signal processing section 31 has a function of allowing the instructed mobile radio 1100 to use two channels simultaneously according to instructions from the control section 40. This is used for simultaneous communication using different radio channels within the same zone during communication, or for simultaneous communication using different time slots of the same channel, and is used for simultaneous communication using different radio channels within the same zone.
This is a function used to enable communication in the slot.

Here, the specific configuration of each radio receiving circuit 35-1, 35-2 is the same as the radio receiving circuit 135 of the mobile radio m1oo shown in FIG. 1B-2.

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 the COD/BBD exemplified in the signal speed conversion circuit group 51 can be used as it is in the signal speed conversion circuit group 38 as described in the above-mentioned document. 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.

Trust from Kanmon Exchange 120! 2! The control or call signals outputted via the L control section 31 are input to a signal speed conversion circuit group 51, where speed (pitch) conversion processing is performed, and then a signal allocation circuit that allocates signals for each time slot. applied to group 52. This signal allocation circuit group 52 is a buffer memory circuit, which stores each section of high-speed signals outputted from the signal speed conversion circuit group 51, and outputs signals from the timing generation circuit 42 given by instructions from the control section 40. With the timing information, the signal in the buffer memory is read out and transmitted to the wireless transmission circuit 32. This timing information is arranged in series with no overlap in time series when viewed from the perspective of call signal correspondence, and if the control signal or control signal and call signal described later are all implemented, it will appear as if it were a continuous signal. It becomes like a wave.

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

The output signal of the signal speed conversion circuit group 51 is sent to the signal assignment circuit group 5.
2 and are given time slots in a predetermined order. Figure 2A (a> SDI, SD2
．． -, SDn indicate that the rate-converted communication signals are applied to each time slot 11 at the output of the radio transmitting circuit 32-1, 32-2 (simply shown as 32).

Here, as shown in the figure, one time slot accommodates a synchronization signal and a control signal or a call signal (and control signal). 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 case, in the service zone of another wireless base station 30 in the same system, the same wireless channel, the same time,
In order to avoid causing radio interference to communications using the slots, the signals contained in empty time slots are limited to only the first part of each slot length (for example, about 5% of the total). It is also possible to prevent the remaining radio waves from being transmitted at all. In this way, FIG. 2A (a
), in the radio transmitting circuits 32-1 and 32-2, signals forming one frame are applied to the modulation circuit in the time slots SD1 to SDn.

This time-series multiplexed signal is amplitude- or angle-modulated in the radio transmitting circuit 32 and then 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 speech signal band or outside the speech 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 (250) 1z) and the high frequency side (3850H2) can be used. This signal is used, for example, when it is desired to send a control signal during a call.

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

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

Additionally, the reason for adding control signals to the time slots that include call signals is to confirm IDs and notify call traffic information, etc., and these can be omitted if they are not needed. .

The above was a case of analog signals, but if a digital data signal is used as the single control signal, it is also possible to digitally encode the audio signal and time-division multiplex the two to transmit. The circuit configuration in this case is shown in FIG. 3C. FIG. 3C shows an example of a case where an audio signal is digitized by a digital encoding circuit 91, the audio signal is multiplexed with a data signal by a multiplex conversion circuit 92, and the resulting signal is 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 130 and input to the radio reception circuit 35. FIG. 2(b) schematically shows this upstream input signal.

That is, time slot SU1. SU2. ...S
Un is a mobile radio 100-1.10C)-2°...
, 100-n to the wireless base station 30. Also, each time slot su1. su2,...,s
If the contents of un are shown in detail, as shown in the lower left of 2nd A(b), it consists of a synchronization signal and a control signal or a call signal. However, it is moved to the wireless base station 30! The synchronization signal may be omitted depending on the distance between the wireless device 100 and the signal speed. Furthermore, the waveform of the radio carrier wave of the above-mentioned uplink radio signal within a time slot is schematically shown in 28th (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 4o, and a synchronization signal and a control signal are generated for each time slot SUI to Sun. The signal or speech signal is separated and output. Each of these signals is input to a signal speed restoration circuit group 38. This circuit is a speed conversion circuit 131 (first
It has a function of inversely converting the signal (Figure B-1), thereby faithfully reproducing the original signal and transmitting it to the gateway exchange 20.

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

As shown in FIG. 1C, the control signal from the control unit 40 is transmitted to each signal assignment circuit 52-1 to 52-1 included in the signal assignment circuit 152.
52-m is applied to the wireless transmitter circuit 32 in parallel with the output of 52-m. However, depending on the speed conversion rate, it is also possible to apply the signal vj to the wireless transmission circuit 32 from the output of the circuit 152 after performing the same processing as the call signal. Next, as shown in FIG. 1B-1, 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, audio signal'g (0,3K)-1z ~3
, oKH2) passing through the signal speed converting circuit group 51 (FIG. 1c), the frequency distribution on the output side is shown in FIG. 38. In other words, if the audio signal is 1 as shown in
If converted by a factor of 5, the frequency distribution of the signal would have been expanded by 1-12 to <4.5KH2-45 in FIG. The figure shows a case where the control signals are simultaneously transmitted using the lower frequency band of the audio signal. Of this signal, the control section g (0,2 to 4.0
kHz) and a speech signal gcH1 (4.5-4.5 KHz, expressed as SDI) are accommodated in a time slot, for example SDl. The same applies to the audio signals accommodated in the other time slots SD2 to S[)n.

That is, time slot SDi (+=2°3.-
, n) accommodates a control signal (0,2~4.0KH7>) and a communication signal CHi (4,5~45Kt-1z). However, the signals within each time slot are arranged in chronological order. Therefore, signals in more than one time slot at a time are never applied to the wireless transmitter 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, fo is a radio carrier frequency. If there are multiple wireless channels given to the system, the signal speed conversion circuit group 51 will be limited to a certain value due to the limits of these frequency intervals. . Let f be the frequency interval of the plurality of wireless channels. , and let fH be the maximum signal speed due to the speeding up of the audio signal in (e) above, then the following inequality must hold between the two.

f>2f.

ep On the other hand, in digital signals, audio is usually digitized at a speed of about 64 kb/s, so it is necessary to read the scale on the horizontal axis in Figure 38, which explains the case of analog signals, by raising it by about one digit. 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 u.
39 to 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. In FIG. 1D sent to the intermediary switch 20, the mobile radio has 100 alternative embodiments 100B.
It is shown. Here, the difference from the mobile radio device 100 shown in FIG. 1B-1 is that two sets of synthesizers 121-1 to 121-4 are provided, and the radio transmitting circuit 132 and the radio receiving circuit 135 have synthesizers. 12
Transmit/receive intermittent controller 1238 for outputs of 1-1 to 121-4
Switch 122-1.12 that is turned on and off under the control of
2-2. This transmission/reception intermittent controller 1
238 opens and closes the switches 122-1 and 122-2 based on instructions from the control unit 140B. With such a configuration, the mobile radio device 100B has the advantage that there is no risk of radio interference occurring, and that it can always perform transmission/reception diversity with the same radio base station 30.

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 radio receiving circuit 135 in Fig. B-1, the downlink (radio base station 30→mobile radio device 100) radio channel (channel CH
Start capturing the control signal included in the control signal (denoted as I).

If the system is provided with multiple radio channels, select the radio channel i with the highest received input electric field.
i) A radio channel instructed by a control signal included in the radio channel; ii) A radio channel (such as a channel with an empty time slot among the time slots in the radio channel) according to the procedure defined in each system. It enters the receiving state for channel CH1 (hereinafter referred to as channel CH1). 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 C1-11, and the switch 122-1 is also fixed in the position of the synthesizer 121-1.

Therefore, when the handset of the telephone section Go○ is off-hook (starting a call) (3201, Fig. 4A), the synthesizer 121-3 of Fig. 1B-1 sets the station oscillator to enable transmission of the wireless channel CH1. A control signal for generating a frequency is received from the control section 40. Further, the switch 122-2 is also turned to the synthesizer 121-3 side, and is in a fixed state.

Next, using the radio channel CHI, the telephone unit 101 sends out a control signal for calling. 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 within one time thrower 1,
Transmitted using the same time slot in the next frame.

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. becomes possible.

Furthermore, this control signal includes control information such as time slots 1 to 1 currently in use and unused time slots (empty time slot display). Depending on the system, the time slot so* <;=1.2°...
, n) may contain only synchronization signals and call signals when they are being used by other communications, but even in such cases, unused time slots usually contain synchronization signals and call signals. By receiving this control signal, the heat is transferred! It is possible to know which time slot the machine A 100 should use to send out the calling signal.

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

In other systems, the time and
In addition to slots, there are cases in which only a control signal indicating the usage status of all time slots is sent to a specific time slot, and no radio waves are sent to other time slots, or which time slots are used. There are also cases where empty slots are not displayed within the slots, and in this case, the following audio multiplex signal SD1. SD2. ..., it is necessary to search for the presence or absence of son one after another and check for empty time slots.

Now, returning to the main topic, the mobile radio device 100 that has received the control information sent from the wireless base 830 by one of the methods described above 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 a call is necessarily made from another mobile radio at the same time, the calling signal t will not be transmitted to the radio base station 30 as well as the call will be transmitted to the radio base station 30 due to call collision, and the operation will have to be restarted from the beginning. When viewed as a system, the probability 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 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. 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 (S202). Search for time slots. The time slot given to the mobile radio device 100 may be Sun, but a search is performed just to be sure. It is mobile radio 1
In addition to 00, it can also be used to respond to simultaneous calls from other mobile radios, or to provide a time slot suitable for the service type or service classification.

As a result, if time slot SD1 is vacant, for example, time slot uplink (mobile radio R100-+radio base station 30) is sent to mobile radio m1oo using time slot SDn of radio channel CH1 by a downlink control signal. SUl.

and instructs to use the corresponding downlink (radio base station 30 → mobile radio device 100) SDl (3203
>. In response, the pre-move iQ device 100 transitions to a state in which it can receive data in the instructed time slot SD1, and also changes the time slot 5U1 (5U1), which is the time slot for the uplink radio channel corresponding to the downlink time slot SD 2A
(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 1222 (S204). At the same time, it sends a slot switching completion report to the wireless base station 30 using the upstream time slot SU1 (3205) and waits for a dial tone (
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). Radio base %11630 has time slot SUI
In addition to , SU3 and Sun are sent as uplink signals from other mobile radio devices 100 in one frame.

The radio base station 30 that has received the slot switching completion report (
3207), sends a calling signal to the barrier exchange [20 5208>, and upon receipt of this, the barrier PA device 20 detects 10 of the mobile radio 100 and selects one of the switch groups included in the barrier switch 20. Turn on the necessary switches (82
09>, send dial tone (3210.4th
Figure B).

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

When transitioning to this state, the telephone unit 1 of the mobile radio device 100
Since a dial tone can be heard from the handset of 01, 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 152
, 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 passes through the signal selection circuit 39-1 of the signal selection circuit u39, 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 (S214), and a call path to the telephone network 10 is set (3215> .

On the other hand, an input signal from the barrier switch 20 (initially a drawing signal,
Once the call is started, the call signal is sent to the wireless base, 1430
After being subjected to speed conversion by the signal speed conversion circuit group 51, the time slot SDI is given by the signal allocation circuit 52-1 of the signal allocation circuit group 52. Then, it is transmitted from the radio transmission circuit 32 to the mobile radio 11100 using the time slot SDI of the downlink radio channel. The mobile radio@100 is on standby for reception in the 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 13.
8 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 turning on the receiver of the telephone unit 101 of the mobile radio device 100 (3217>), and the end of the 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 (S218>, ``control unit'' 140
Then, the operation of the transmission/reception intermittent controller 123 is stopped, and the switches 122-1 and 12:2-2 are fixed to the output terminals of the synthesizers 121-1 and 121-2, respectively.

On the other hand, in the control unit 40 of the radio base station 30, the mobile radio device 1
5219>, 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 radio 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 by the signal rate 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, 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 determines the ID of the mobile radio device 100 using an empty slot behind the downlink time slot of the wireless channel C1''1 addressed to the mobile radio device 100, for example, using SDI.
Signal 10 Incoming call signal display Signalman time slot usage signal (
The mobile radio device 100 uses, for example, SUl corresponding to SDl).

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. The 1ilJ control unit 140 confirms that this signal is an incoming call signal to its own mobile radio 100, so it makes a ring tone from the telephone unit 101 and at the same time waits at the designated time slot SD1.5LJI. The transmission/reception intermittent controller 123 is operated to do so, and the switches 122-1 and 122-2 are turned on and off. In this way, the state has shifted to a state in which calls can be made.

(3) Channel (time slot) switching during a call within the same radio zone Even though the mobile radio 100 is in the service zone of the same radio base station 30, switching from one radio channel to another radio channel, or from the same radio The operation of switching from a certain time slot during a call to another time slot in a channel will be described.

As the mobile radio device 100 moves in a car or while walking, the relative distance approaches the mobile radio device communicating within the service zone of another radio base station 30 in the same system, or the radio wave propagation state This is due to the fact that due to fluctuations in the number of radio stations, they are now subject to interference on the same radio channel and in the same time slot.

Countermeasures against this interference will be explained below.
At the same time, it is essential to explain that there is no instantaneous interruption at all due to channel switching, which is a feature of the present invention.

The mobile radio device 100 includes a synthesizer 121-1゜121
-3, the radio receiving circuit 135, and the radio transmitting circuit 132 to communicate with the radio base station 30 and the time slot upstream 5U1-1 of the communication channel CH1. It is assumed that communication is in progress using downlink 5D1-1. However, suppose that for some reason, the interference detection unit 162 of the mobile radio device 100 detects the occurrence of radio interference of another communication. The interference detector 162 immediately notifies the control unit 140 of this fact.

The 1tIl control unit 140 inquires of the reception quality monitoring unit 158 whether or not the input electric field has decreased due to the increased relative distance from the wireless base station 30, but it is found that the input electric field has not decreased. As a result, the control unit 140 recognizes that radio interference has occurred due to other communications, and decides to switch to another radio channel or to switch busy time slots within the same radio zone.

Note that in the above case, when there is a notification from the reception quality monitoring unit 158 that the input electric field has decreased, the mobile radio Ia 100 moves away from the radio base station 30 and connects to other nearby radio base stations 30.
Mobile radio +1100 and radio base station 3
This is because the relative distance between the wireless base station 30 and the wireless base station 30 increases, and the call quality deteriorates accordingly, and it is necessary to perform channel switching between adjacent wireless base stations 30 during a call.

Regarding the flow of operation in this case, Figures 58 to 5D
This will be explained using figures. Here, a mobile radio device 100B (hereinafter simply referred to as mobile radio device 100) shown in FIG. 1D is used.

) is shown as a flow chart showing the flow of operations when switching channels during a call in a system using the system.

Gateway exchange 20. The radio base station 30-1, 30-2 and the mobile radio 100 start operating, and the switch 5WI-1-1 of the switch group 23 included in the gateway exchange 20 is on, and the radio base station 30-1 and the mobile radio 100 start operating. Communication is in progress with the mobile radio device 100. For this communication, the wireless channel C specified by two communication control units included in the gateway exchange 20 is used.
I-11 time slot 5DI-1, 3IJ1-1
．． Downlink frequency F1 and uplink frequency f1 are used (S
101, Figure 5A).

The wireless base station 30-1 that is currently communicating constantly sends out a reception status report from the mobile wireless device 100 (S102>, and the S/N monitoring unit 25 of the barrier switch 20 receives this report and determines that the call quality is at level L1. It is monitored to see if it has deteriorated further (3103).

If the call quality has deteriorated below level L1 (Sl
○3YES) From the communication control unit 21 to the wireless base station 30
-1 to the wireless base station 30 in the vicinity of the wireless base station 3
0-1 and the mobile radio device 100, the uplink frequency f1. An instruction is given to monitor and receive the signal of time slot 5tJ1-1 (S104).

Each of the surrounding wireless base stations 30 (for example, 30-2) that received the monitor reception instruction monitors and receives the signal of frequency f1. Please report to the monitoring department 2231
06), the monitor reception quality from each radio base station 30 is measured and compared, and it is detected that, for example, the speech quality of the radio base station 30-2 is better than a certain standard level L2 and is the best (S107YES).

Therefore, the communication control unit 21 allows the mobile radio device 100 to move from the zone covered by the radio base station 30-1 to the radio base station 30-2.
3108 seems to have moved to the zone covered by
, FIG. 5B), searches 510 for a channel with a free time slot that can be used by the wireless base station 30-2 to switch to communication with the wireless base station 30-2.
9), so that time slot 5 of channel CH2
D2-2 and 5U2-2 are determined (S110).

The communication control section 21 provides the control section 140 with the mobile radio device 1.
Channel C is sent to the transmitter 132 and receiver 135 of
A command is given to prepare for communication in time slot 5D2-2°5U2-2 of H2 (3111).

Time slot 5D2-2, 5 of this channel CH2
The communication preparation command for using U2-2 is sent to the wireless base station 3.
0-2, time slot 5 of channel CH2
D2-2. SU: Prepare for communication by 2-2 (31
12). This command is simultaneously transmitted from the radio base station 30-1 in time slot 5D1i of channel CHI (S113). Mobile radio 1100 uses this channel C
H2, time slot 5D2-2, 5U2-2, receive communication preparation command on frequency 02 (3114), channel C+-12, time slot 5D2-2.5U2
- Preparations to enable communication by 2, i.e., t
The il control unit 140 (B> instructs the synthesizers 121-2 and 121-4 to receive frequency G2 and transmit at frequency 02, and the transmission/reception intermittent controller 123 controls the time slots 5D2-2 and 121-4. The operation starts using 5U2-2 (S115, Fig. 5C).

Channel CI-12 time slot 802-2°5
When the mobile radio device 100 is ready to communicate using Q-U2-2, it reports the completion of preparation to the radio base station 30-2 using time slot 5U2-2 of channel CH2 ( 3116).

Upon receiving this report, the wireless base station 30-2 performs step 51.
Time slot 5D2-2.5U2- prepared in 12
2 confirms that the preparations within the wireless base station 30-2 are complete, but does not send a report to the barrier switch 20 (S117).

When the gateway exchange 20 confirms the completion of communication preparation between the wireless base station 30-2 and the mobile wireless device Go○○ using time slots 5D2-2 and 5U2-2 (3118),
Leave the switch 5W1-1-1 of switch details 23 on, and also turn on the switch 5W2-1-1 (311
9). Therefore, the communication control unit 21 included in the barrier switch 20
commands the radio base station 30-2 to start communication with the mobile radio 1100 using time slots 5D2-2.5U2-2 (S120).

Upon receiving this communication start command (3121>, the wireless base station 30-2 transmits the communication start command in time slot SD2'
-2 is used to send (3122>.

The mobile radio device 100 uses an ID signal, which is an identification signal for identifying a mobile radio device, to time slot 5D2-2.
．． Please confirm the start of communication by 5U2-2 (3123),
Using the time slot 5LJ2-2, the radio base station 302 sends out a communication signal including the ID signal (Sl 24,), and receives this communication signal.
2'-2, 5U22 reports that communication has started (
3125>.

Upon receiving this report, the S/N monitoring unit 25 of the barrier exchange 120 confirms the start of communication in time slot 5D2-2. Measure the quality level of communication between
When a certain quality level is detected to be 2 or higher (3
127YES, FIG. 5D), time slot 5D1-1.5 between radio base station 30-1 and mobile radio 100
Wireless base station 3 stops communication that was being performed using UI-1.
0-1 and 30-2 (S128>.

As a result, the radio base station 30-1 is connected to the channel C)"1.
Communication using time slots 5DI-1 and 5UI-1 is turned off (S129). Furthermore, the radio base station 30-2 that has received the command to stop communication through channel CHI forwards the command (5130), and when the mobile radio device 100 receives the command to stop communication through channel Cl-11 (S1
31), the operation of synthesizers 121-1 and 121-3 is stopped, and the changeover switch 22-1 is switched to synthesizer 1.
21-2 side, the changeover switch 12:2-2 continues to turn on and off at a predetermined timing between the synthesizer 121-4 side and the channel CH2 time slot 5D2-2.5U2-. Make only 2 work,
Channel C1-1'l communication stop report is sent using time slot 5U2-2 of channel CH2 (S13
2). Upon receiving this, the radio base 830-2 transfers the communication stop report for channel CH1 and time slot 5UI-1 (S133).

Communication control unit 2 of barrier switch 20 receives communication stop report from channel C)-11, time slot 5IJ11
1, the switch 5W2-1-1 of the switch group 23 remains on, and the switch 5W11-1 is turned off (S1
34).

This ends the channel switching operation period, and with the switch 5W2-1-1 in the on state, the mobile radio 100 is connected to the radio base station 30-2 using the channel CH2, the downlink frequency 62, and the uplink frequency g2. In between, the -shun disconnection,
Communication can be continued without the whistle sound being mixed in (31
35).

The above description has been made on the assumption that the same radio channel is not allocated between adjacent zones when switching channels during a call in the system of the present invention. In actual small zone systems currently in use, this is strictly adhered to. However, when time-division communication is performed as in the present invention, the above conditions do not necessarily have to be complied with even in the case of a small zone system. In other words, even if two adjacent zones use the same wireless channel,
This is because if the time slots are made different, there is no risk of radio interference occurring as described above.

Next, it will be explained that mobile radio signals used in the present invention exhibit strong resistance even when radio interference occurs due to other communications during a call within a certain radio zone. A method for implementing radio channel or time slot switching within the same zone to avoid interference at the same time is described.

First, the mobile radio device 100 reports to the radio base station 30 that time slot switching should be performed using an out-of-band control signal of a speech signal.

Here, even though the audio signal within each time slot is considerably degraded by radio interference, the control signal within the same slot is highly resistant to this. Therefore, various measures have been taken to make tone signals and digital signals less susceptible to interference, such as using low-speed data, error correction, and retransmission.

In the unlikely event that the control signal from the wireless base station 30 becomes completely unreceivable, this fact is reported using the control signal in the upstream time slot SU1. Since the radio base station 30 has a fixed location, it generally has a lower probability of receiving interference than the mobile radio device 100, and can receive this control signal better.

Then, the wireless base station 30 stops transmitting the call signal,
An instruction to be described below is transmitted to the mobile radio 100 in the form of a control signal that allows all time slots SDI to be easily received by the mobile radio 100. This signal is transmitted to the mobile radio 100
can be easily received even under interference.

Now, upon receiving a control signal from the mobile radio device 100 notifying the occurrence of interference, or recognizing the occurrence of radio interference itself, the radio base station 30 investigates whether there is an empty time slot within the same radio channel. However, time slot SD2. Assume that it is found that SU2 is usable (see FIGS. 2A and 2B). Then, the mobile radio device 100 is instructed to use this for transmission and reception.

Therefore, the control unit 140 of the mobile radio FM 100 uses the synthesizer 121-1 to
Transmission/reception is performed with the timing generator 142 so that the transmission wave from the wireless base station 30 is being received in the time slot 5D1-1, and the timing generator 142 is also able to receive the same signal in the time slot 5D1-2. Intermittent controller 123
instruct.

When the radio base station 30 emits a transmission wave in time slot 5D12, the mobile radio Bu 100 changes the operation of the transmission/reception intermittent controller 123 to 1, radio channel C.
The state in which the signal was being transmitted to the radio base station 30-1 using time slot 5U1-1 of channel CHI is changed to a state in which the same signal can be transmitted using time slot 5U1-2 of channel CHI. Thus, time slot 5tJ1-1. SU”l-2,3D1-1.3D1
-2 is now transmitted and received in parallel.
-2 and the quality of the same time slot continues until the radio base station 30 confirms that the quality of the same time slot is 2 or higher on a certain level, and then the channel CH1 time slot 5
D1-1 and 5U1-1 are opened, and communication continues without momentary interruption using only time slots 5D1-2 and 5U1-2 of channel CH1.

The switching frequency f1 of the changeover switch 122-1 or 122-2 during this switching transmission/reception period should be twice the value before the start of the switching operation.

In other words, if the number of time slots in one frame included in wireless channel CH1 is n, and the time interval between one time slot is T1, then f = (nT1) x
It is given by 2.

FIGS. 68 to 6E are flow charts showing the flow of operations when switching channels when co-channel interference occurs during a call in the system shown in FIGS. 18 to 1D. ing.

Gateway exchange 20. Radio base station 30 and mobile radio device 10
0 has started operating, the switch 5W1-1-1 of the switch group 23 included in the barrier exchange 20 is on, and communication is in progress between the radio base station 30 and the mobile radio 100. For this communication, time slot 5D1- of radio channel CH1 instructed by control unit 40 of radio base station 30
1,5U1-1. Downstream frequency F1 and upstream frequency f1 are used (S351, Fig. 6A).

A mobile radio [100
reception status reports from, for example, fading or
A report that reception is not possible due to interference is issued by a control signal in each time slot used for communication (3352), and the radio base station 30 receiving this report,
Transmission quality monitoring section 34 within the own station (this is the mobile radio device 100)
(having the function of both the reception quality monitoring unit 158 and the interference detection unit 162) is comprehensively considered, and it is determined whether or not to execute busy zone switching or time/slot switching within the same zone. . If the cause of the inability to receive is due to a decrease in the receiving electric field, the process moves to steps 5102 (FIG. 5A) to 3135 (FIG. 5D) (S35).
3 YES).

If the cause of the inability to receive is not due to a drop in the received electric field (3353 NO), check whether it is due to co-channel interference (3354, Figure 6B), and determine that it is necessary to change the time slot within the same channel.3354 , 6th
(Figure B), it is determined that it is necessary to change the time slot within the same channel (5355), and reports to the radio base station 30 that it should be changed to a communication channel or another time slot due to interference (S356). Therefore, the control unit 40 of the wireless base station 30 that received this (3357)
If it is determined that there is co-channel interference (interference in the same time slot) (S354YES>, search for the presence or absence of an empty time slot, and select time slot 5D1-2.5.
Determine U1-2 (3358). The control unit 40 sends time slot 2 of the channel CH1, that is, 5D1-
2.5 Command to prepare for communication on UI-2 (
S359, Figure 6C). This command is time slot S
, D1-1, and the mobile radio 1
00 receives this communication preparation command (3360), channel CH1, time slot 5D1-2, 5kJ1-2.
Preparation to enable communication by time slots 5D1-2 . The operation is made to also use S[Jl-2 (3361).

On the other hand, at the wireless base station 30, the time slot 5D1-
In order to prepare for parallel communication using 1.1-2.5U1-1.1-2, the signal selection circuit 38-1 of the signal selection circuit group 38
．． 38-2, signal speed restoration circuit 38-1.38-2 of signal speed restoration circuit group 38 receives in parallel, signal speed conversion circuit 51-1.51-2 of signal speed conversion circuit group 51, signal allocation circuit group The control unit 40 instructs the signal processing unit 31 to receive the signals in parallel by the signal allocation circuits 52-1 and 52-2 (3362).

When the mobile radio 100 is ready to communicate using the time slots 5D1-2 and 5U1-2 of the channel CH1, the mobile radio 11100 sends a report of preparation completion to the control in the time slot 5U1-1. A report is made to the wireless base station 30 using the signal (S363). Upon receiving this report, the radio base station 30 selects time slot 5DI-2,
Preparations for parallel transmission and reception using 5UI-2 are complete. 3364
), start parallel transmission and reception (3365, Figure 6D).

That is, 5D1-2 sends out a communication signal including an ID signal, and the mobile radio device 100 receiving this communication signal (
S366), time slot 5D addressed to the wireless base station 30
After confirming that the I-2 signal was received well (3
367), and a confirmation signal is transmitted by a control signal in time slot 5U1-2 (3368). Wireless base station 30
When this report is received (3369), the transmission quality of the time slot 5U1-2 is checked by the transmission quality monitoring unit 34 (3370), and the time slot between the radio base station 30 and the mobile radio device 100 is checked. 5DI-1, 5U1-
The mobile radio commands 100 to stop the communication that was being carried out using 1 (3371. Fig. 6E). The mobile radio device 100 receiving this (S372) selects time slots 1 to 5D.
1-1.5Turn off communication by U1-1 (S373
), that is, the IIJ control unit 140 is the transmission/reception intermittent controller 1
23 to control time slots 5D1-2, 5U1-
In addition, communication stop reports for time slots 5U1-1 and 5D1-1 are sent to channel CH.
Send using time slot 5U1-2 of 'l (
3374). The radio base station 30 that received this (337
5), execute a similar bow at your own station (3376).

As a result, the channel switching operation period ends, and the mobile radio device 50 is disconnected from the radio base station 30 for an instant.
Communication can be continued without noise (83
77).

In the above description, in the system of the present invention, when performing channel switching during a call within the same zone, time slot switching is performed on the same radio channel. However, this does not necessarily have to be done within the same radio channel; different radio channels may be used. However, in that case, synthesizer 12
Since it is necessary to change the frequencies generated by 1-1 and 121-3 according to the radio channel, it is necessary to provide a synthesizer with a fast rise characteristic.

Alternatively, as shown in FIG. 1D, the synthesizer 121-
1 to 121-4 are prepared, two for transmitting and two for receiving, one for transmitting and one for receiving at normal times, and used when changing the communication channel within the same zone which involves changing the communication channel as described above. In this case, even more stable operation can be expected.

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 (transmitted by mobile radio device 100, received by radio base station 30) radio signal.

First, assume that all uplink radio signals are empty lines, that is, no time slots are 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, the radio transmitting circuit 132 sends a control signal (a call message @ if a call path is set) to the radio base station 30 in response to a signal from the timing generating circuit 142.

Similarly, if there is a call from another mobile radio, a control or communication 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 voice signal (for signals in analog or digital format) which is the output signal (or control signal) of the telephone unit 101 in FIG. 1B-1 can be expressed as follows.

μ(1)-, da-cos(ω・↑+θ(),,
+ 1 Also, the control signal that exists outside the band is μ (1) =, Σa = CO3 (ω- to θi) C+ =
m+11 I Here, a· represents the magnitude of the amplitude, ωi represents the thoracic wave number of the signal, and θ· represents the phase when ↑=O. 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 1q is: I= I□ sin f <ω0μ(1)) dt=IQ
Sin(ωt+5(t)>(3) or 1=r□ sin f<ω10μ(1)10μ.(t))
dt= I□ Sin (ω↑+5(t) +s.(t
) ) However, m・=aH/ωi (i=1.2.3...n) (4
) 5(1) 10S shown by the formula. (1) will represent a general form of transmission signal.

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

I-(Io1/n>[1+2i1(n/ml)XSi
n (m7r/n)CO5mDtlxsin (Ω1
j + 61 (j) + S cl (t) > where n is the number of slots in one frame] (equally spaced), 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= (101/n) [1+2-Fl(n/m''))
xs+n (Ω1↑10S1 m +5o1(t))
+ (102/rl) [1+2Σ(n/mπ)) m=1 xsin (mπ/n> xcos mo (t-2π/ (no))
]xsin (Ω2 i + S2 (t) +s.2
(t) )xsin (mπ/n> xcos mp (t-4yr/ (no))]xsi
n (Ω3t+53(1)+5o3(1))+(I□o
/n> [1+2Σ (n/mπ)) m=1 xsin (mπ/n) xsin (mπ/n) cos mp t]
xcos mp (t-2(n-1) yr/ (np
) ) ]xsin (Ω t+s (t) +
5on(t))n However, p is the switching angular frequency, m is a positive odd number, and the switching times for n input waves are set at equal intervals.

Also Ω1. Ω2. ..., Ω. Although the carrier frequencies transmitted from each mobile radio 1100 are on the same radio channel, they are slightly different, so different symbols are used. S.
(1) and S. The same applies to 1(t) (i=1.2°..., n).

The radio signal transmitted from the radio base station 30 in FIG. 1A is
The mobile radio device 100 that communicates with each other receives only the signals necessary for itself in the equation (6) using 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 length limiter included in the receiving section 137 in FIG. 1B-1, it takes the form shown in the equation below.

■−△sin (Ω 151(t) +5o1(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 demodulated output is e(1)=μ(1)10μ. (1) Obtain. 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 for the mobile radio 100 itself as in the case of the mobile radio 100, it is necessary to receive all the signals sent chronologically from a large number of mobile radios 1100. They differ in certain respects.

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 = (101/n > [sin (Ω1↑+U
1(t))+(n/π)sin(π/n> x[5in((Ω1+p)↑+U, (t))+si
n ((ΩID) t+U1 (t) ) ]+
(n/3; 1 sin (37r/n>x[5in(
(Ω1+3p)j+U1 (j)(6π/n>(n-1
>) +5in((Ω1 3p)t+U1 (t)+(6π/
n)(n-1>)] + (n15π) sin (57r/rl)x[5i
n((Ω1 +5p)t+U1(1)−(10π/n>
(n-1>) +5in((Ω1 5p)t+U1(1)+(10π/
n＞(n−1＞)] +・・・・・・ ]+ (
I02/ n > [sin (Ω2 t+U2 (t
) )+(n/π) sin(π/n> x[5in((Ω2 +, D) t+U2 (t) )
+5in((Ω2 ri)t+U2(1))] ten(n/
3π) sin (37r/rl) x [5in((Ω +
3D) j+U2 (i) one (6π/n>(n-1)) +5in((Ω2 ap> j-)-U2
(t)+(6π/n>(n-1>)] 10(n15π) Sin (57r/n>x[5in((
Ω2+5p)j+U2 (t)-(10π/n>(n-
1>) +5in((Ω2 5D)i+U2(t)+(10π
/n)(n-1〉)] +・・・・・・
]+ <I On/n> [Sin (Ωnt
+ U n (t) ) + (n/π) sin (π/")
) x[5in((Ω +p)t+U,(t))+5in(
(Ω −p)t+Un(t)) ]] + (n/3yr) sir+ (37r/rl)x
[5in((Ω, +3p)t+Un(t)(6π/n
>(n-1)) +5in((Ω-3p)t+Un(t)(6π/n>
(n-1>)] + (n15π) sin (5π/n) x [5in((
Ω +5p)t+Uo(t)(10π/n>(n-1>
) +5in((Ω -5p> t+Un(t)(10π/
n>(n-1)Ll 10...JHowever, U・(B=s・(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.

(1) If4 wireless 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), the adjacent radio channel interference is the thickest (this would be the case when all implementations, that is, all time slots are in use. Also, for convenience of calculation, the carrier wave frequency Ωi ( i=1.2...
n) and the transmitted signal U.<r=1.2.・・・
., n), Ω1=Ω2=...-Ω.

Even if U1=u2=.=un, the influence on the amount of interference is ignored (actually, this is the maximum amount of interference that can occur).

Furthermore, in an actual system, it may be set as l0l-102'''''''''l0n=■0(8'), so equation (7) can be expressed as follows.

1/ n= (I□ / n > (Sin (Ω1 1 U1 (t) ) + (n/Vr) sin (yr/
n) x[5in((Ω1+D) t+U1(
t) )+5in((ΩI I)) i+U1 [j
) ) ] + (n/3π) sin (3yr/n)
X[5in((Ω1+3D)t+U1(1
)=(6π/n>(n-1>) +5in((Ω1 31)) t+U1 (j)-(6
π/n) (n-1))] + (n15π) sin (5π/n>x[5in(
(Ω1 +5p)j+U1 m-(10π/n>(n-
1>) 15in((Ω1-5p)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 phase of the carrier wave, the energy ( voltage) is expressed as a peak value (this results in a greater evaluation of the influence of interfering radio waves), as shown in the following equation.

1/n=(Io/n)M+(n/π)Sin(π/n>+(n/3π)sin(3π/n)+...)-(I
□/n＞((n/yr) sin (yr/n)+ (
n/3π) sin (37r/n) +-1 However,
In view of other radio channels, the positions of the carrier frequencies of the jamming waves in F are located at p=o, that is, above and below the main carrier frequency, ±p, ±2o, ±3p, etc., respectively. . 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), . In other words, if we set these as 1, equation (10) becomes: J/I□ =1+ (n/π)(1+1/3+115+
...+1/(2n-1) +...) +(n/π) (1+1/3 +115+...+1/(2n-1) 10...) The second side of this equation (11) The first term 1 refers to the main carrier component, the second item (n/π)() refers to the subcarrier component in the upper frequency band of the main carrier, and the third item (
n/π)() represents the subcarrier component in the lower frequency band.

When the energy distribution of a large number of carrier waves shown in equation (11) is shown on the frequency axis, it becomes as shown in FIG. From equation (11), the reserved subcarrier energy in the wireless channel (
The energy within 10 KH'Z above and below the center frequency is compared with the energy within 10 to 20 KHz of the amplitude value). First, the energy (voltage value) E - (10KllZ) within 10Kllz is 〒2n/πx 5
．． 5506 Also, the energy E (2
0 to H2) = 2n/πx O, 1421 Therefore, R = E (20KH2) / E (IOKH2) It can be seen that it is gradually reduced to 0.0256 (14), that is, about 1/40.

Similarly, if we calculate 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 is likely to cause radio wave interference to other channels.

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

Adjacent channels shown in Figure 7 have a channel spacing of 125K.
If the subcarrier frequency 75KHz to 175K) IZ component causes interference within this channel, the total power is calculated from equation (11), while the energy of the main carrier (this is (equal to the energy of the main carrier wave) is 1, so the ratio of signal to interference radio waves (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 calculations, p was 207c radians (10Hz), but if we perform similar calculations for the case where p is 100H2 (the purpose of increasing p 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 was based on mobile radio [100]
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 periodic signals and control signals are different, 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 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-4-1) l)) t+U(t
) )-COS((Ω-(2m+1) p)t+tJ
(t))] To specifically obtain equation (16), all that is required is to perform the same numerical calculations as performed for equation (1). Therefore, if the characteristics of the filtering circuit included in the wireless transmitting circuit 32 are wideband, m□ is, for example, 10000 (l
0KZX 10000=100KH2) or more, the influence of self-channel interference can be ignored. In an actual circuit, this condition can be easily satisfied.

(I[l) Co-channel interference Co-channel interference occurs when the present invention is applied to a small zone system, when a wireless channel being used in a radio zone is used in another zone that is located in a different location. This occurs when radio waves from the same radio channel mix together.

In FIG. 8, 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. 8, 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 the conventional analog system, the interference value is known for the D/U value 1q 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 is impossible to accurately determine the modulation value unless the system is actually constructed and measured. However, if the conventional D/U, i'l: customer value is used, it is expected to be on the safe side.

(IV) Method for removing pulse noise when receiving signals As already explained, when receiving a time-division signal according to the present invention and obtaining a frequency (phase) discriminator output, the output signal is (
5') However, 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, and b) rounding of the signal waveform due to the band characteristics of the intermediate frequency amplifier 43. Things related to both transmission and reception 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. In addition, another 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 in the transmission/reception ii#ii (transmission/reception 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).

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

) 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 499 circuit, the transmitter/receiver filter section, etc. is small and will therefore be omitted.

Of the above, 1) is because, for example, in the aforementioned car phone, the distance between transmitting and receiving is at most about 10 floors (wired section omitted), so 10M/300000KJn/sec = 1/30
m5ecAlso, for mobile phones, a system has been proposed in which the communication area of one wireless base station is made into an extremely small zone with a radius of approximately 25 m (proposal of a "heartland" mobile phone system - an approach to ultimate communication). ″IEICE technical report
C8 Study Group, November 1986, C386-885 and "Mobile Phone System" Patent Application 1986-64023).

In the mobile phone system described above, the distance between transmitting and receiving is approximately 100 m at most (the @ line section is omitted), so 100 m/300000 KIn/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. 9A and 9B.

In FIG. 9A, the signal rate 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 period T required by the unit of speed (pitch) conversion (time flows from left to right) 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 output compressed signal A shown in (b) coincides with the trailing edge of the compressed signal A shown in (b). The mobile radio device 100 receives the compressed signal A at the timing shown in (d) at the input of the speed restoration circuit 138, and outputs it as shown in (a). The signal A shown is restored and output as shown in <e>.Here, the delay time τ from the leading edge of signal A in (a) to the leading edge of signal A in (e)
1 is T-cho/n. However, the transmission time from the transmitter output section to the spatial transmission section and the reception section output of the mobile radio DjlOO was ignored.

In FIG. 9B, the signal speed conversion circuit 51 of the radio base station 30
-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 transmitting circuit 32 is (
The mobile radio device 100 that has received this becomes as shown in C).
The input of the speed restoration circuit 138 becomes as shown in (d), and at the same time as the trailing edge of the compressed signal A, the leading edge of the signal A shown in (e), which has been expanded by n times and restored, is as shown in (d). Sent out. Therefore, from the bottom of the column shown in (e),
n=τ2 [A delayed delay time τ2 occurs.

The circuit for processing the signal shown in FIG. 9A 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. 9B, 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 the transmission signal to 1 time thrower 1 (1 section) is T = 1/10 seconds time compression coefficient n = 10, then 2τ1 = 2X1/10 (1-1/10) = 18/100
=0.18 seconds (180ms) 2τ2 =2x1/10 (1+1/10) = 22/1
00=0.22 seconds (220 msec). On the other hand, the delay time 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, the number of kings is decreased from the above example, and T=1/100.
seconds, time compression coefficient n='loo, then 2τ1 =
2X Go/100) (1-Go/100) = 2X99/10
000 → 0.02 seconds (20ms) 2τ2 = 2x1/100) (1+1/100) -20
2/10000 → 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. The above conditions can be satisfied by giving . (The time for one frame should be reduced to 1/10).

The above is the delay time ω that is inevitably determined by system design, and the delay time of the wired system 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.
If you are at a distance of 10 KIn from 0, the delay time difference is 1/30 m5ec as described above. That is, since the time throwers 1 to 1 may double Q and Q by about 3 msec, it is necessary to provide them with a protection opening 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 must be 100 yyt, so the delay time difference is 0.003 msec.

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 has 10 time slots, i.e. audio 1
0 channel can be transmitted. The required frequency bandwidth is 3Kl-(z x10 = 30!-tz with a protection band, ±40K as shown in Figure 10(a))-12
Set to . 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 (1 audio channel/carrier wave), the baseband signal of 1 wireless channel is 1 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 10(b)).
In Japan, this standard is widely used in cordless telephones and the like in the 250MHz/400M)-IZ band.

) Therefore, in order to transmit 10 channels of audio signals simultaneously, 12.5K! z x10=1 25Kl
-1z is necessary.

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 becomes (3!-1zxl○
O +50 (guard band > KH2) x2 = 700KHz In conventional FM communication (SCPC), 12.5KHz x100 = 1250K l-I 22
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 Haltiple 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) In the case of DMS90 system (References; F,
Lindell et al.”[＞1g1tal Ce1lula
r Radio for the1990s”Te
communications P, 254-26.
5 Oct.

1987> This system can multiplex transmit 10 audio channels (1 channel is 16 bits/second) at a transmission rate of 340 bits/second, but the carrier spacing (required frequency bandwidth)
is 300KH2.

Therefore, the frequency utilization ratio of the present invention in 1) and the DMS 90 in 3> is as follows: 80:300=0.267 In other words, 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 virtually eliminated. Therefore, in the event that radio interference occurs, channel switching or switching to time thrower 1 can be done without any interruption without adversely affecting the signal within the same radio zone. Therefore, effect 1 of the present invention is extremely large. I'll go.

[Brief explanation of drawings]

FIG. 1A is a block diagram showing the configuration of the barrier switch included in the system of the present invention and its connection relationship with the telephone network and radio base station. FIG. 1B-1 is a circuit diagram of a mobile radio used in the system of the present invention. 1B-2 is a detailed circuit diagram of the radio receiving circuit shown in FIG. 1B-1; FIG. 1C is a circuit diagram of the radio base station used in the system of the present invention; FIG. 1D is a mobile A circuit configuration diagram showing another embodiment of the radio device, FIG. 2A is a time slot structure diagram for explaining time throwers 1 to 1 used in the system of the present invention, and FIG. 2B is a time slot radio diagram. Waveform diagrams showing signal waveforms, Figures 3A and 38, are for telephone signals and
! A spectrum diagram showing the spectrum of the I signal, FIG. 3C is a circuit configuration diagram for multiplexing a voice signal and a data signal, FIGS. 4A and 4B are a flowchart showing the flow of the calling operation of the system according to the present invention, and FIG. 5B, 5C, and 5D are flowcharts showing the operation flow of channel switching during a call as the mobile radio moves in the system according to the present invention; FIGS. 6A, 6B, 6C, Figures 6D and 6E
FIG. 7 is a flowchart showing the flow of channel switching operations to deal with interference during a call in the system according to the present invention; FIG. 7 is a spectrum diagram for explaining radio wave interference to adjacent channels in this system; FIG. 10 is a configuration diagram showing a small zone configuration to which the present invention is applied; FIGS. 9A and 9B are timing charts for explaining the delay time that occurs in the compression and expansion of signals entering this system; The figure is a spectrum diagram for explaining the required bandwidth of this system and the conventional system, and FIG. 11 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 transmission circuit 34...Transmission quality monitoring section 35...Wireless reception circuit 38... 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 assignment circuit group 2-1 to 52-n...Signal assignment circuit 1...Digital encoding circuit 2...Multiple conversion circuit 00.100-1 to 100-n-...Mobile radio device 01.
...Telephone unit 20...Reference crystal oscillator 21-1.121-2...Synthesizer 22-1, 1
22-2...Switch 23...Transmission/reception intermittent controller 31...Speed conversion circuit 32...Wireless transmission circuit 34...Transmission section 36...Reception mixer 38...Speed restoration circuit 41. ... Clock regenerator 42 ... Timing generator 43 ... Intermediate frequency amplifier 44 ... Gate circuit 45 ... Discriminator 58 ... Reception quality monitoring section 146 ... Gate circuit 133 ... Transmission Mixer 135...Radio receiving circuit 137...Receiving section 62...Interference detector.

Claims (1)

[Scope of Claims] Each radio base means (30) each covers a plurality of zones and constitutes a service area, and each mobile base means (30) moves across the plurality of zones and communicates with the radio base means. A system in mobile communications using radio means (100) and barrier exchange means (20) for exchanging communications between said radio base means and said mobile radio means, wherein said radio base means comprises a plurality of Signal speed converting means (51) for converting the speed of each segmented signal to high speed, and signal allocation for serially outputting in time series at the timing assigned to the plurality of segmented signals converted to high speed. means (52); wireless transmission means (32) for transmitting the output of the signal allocation means as radio waves; a wireless receiving means (35) for receiving radio waves sent to the radio receiving means; and upon receiving the output of the wireless receiving means, converting the plurality of divided signals sent serially into parallel signals, and converting each divided signal into parallel signals. a signal selection means (39) for outputting a signal; 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; and the mobile radio means. transmission quality monitoring means (34) for monitoring the transmission quality of a radio transmission path between the mobile radio means and the mobile radio means based on a report from at least one of the transmission quality monitoring means and the mobile radio means; a radio base station control means (40) for controlling at least one of the radio channel and time slot used for communication between the mobile radio means and the mobile radio means to continue the communication; , radio receiving means (135, 122) for receiving predetermined divided signals of 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. , a speed conversion means (131) for dividing the signal to be transmitted into predetermined time units and converting the speed at high speed; and a wireless transmission for transmitting the output of the speed conversion means as radio waves at a predetermined timing. Means (132, 122-
2, 123); reception quality monitoring means (158) for monitoring the reception quality of signals received from the radio base means; mobile radio control means (140) for reporting to and controlling communication with said radio base means using radio channels and time slots based on instructions from said radio base means; Time division communication system in communication.