JPH02309826A - Time division communication method in mobile communication - Google Patents

Abstract

PURPOSE:To enhance the effective utilization of a frequency by assigning a time slot assigned to a surrounding radio base station to a specific radio base station tentatively when communication traffic is in congestion. CONSTITUTION:A function of deciding a radio channel, a time slot and radio wave transmission stop used for the communication with a mobile radio equipment in radio base stations 30-1-30-n is provided to a gate exchange 20 as an interface function and a control function of a mobile radio communication network connecting to other telephone network 10. Thus, plural time slots are given to a terminal equipment using a broad band signal within a permissible range of a communication traffic to attain the transmission. Moreover, the time slot having been assigned to the radio base stations 30-1-30-n around a congestion zone is assigned tentatively to one of the radio base stations 30-1-30-n in charge of the congestion zone when the communication traffic is in congestion to relax the communication traffic. Thus, the system with high frequency utilizing efficiency is built up.

Description

[Detailed description of the invention] [Industrial application field] The present invention relates to a time division communication method in mobile communication.

More specifically, in mobile communication that employs a time-division communication system that uses a small zone configuration, one mobile terminal
It is possible to implement a transmitting/receiving diversity method of communicating with one wireless base station and simultaneously communicating a communication signal with the same content with another nearby wireless base station using the same or different wireless channel, The present invention relates to a method for efficiently processing call traffic by taking into consideration the situation in which call traffic occurs within a system.

"Prior art" In conventional mobile communications, it has been adopted, for example, in the automobile system of NTT (Nippon Telegraph and Telephone Corporation), which provides commercial services.This will be explained with reference to Fig. 15. The station 13 is assigned a plurality of radio channels for simultaneous communication with a plurality of mobile radios 15 mounted in each of the numerous vehicles within the zone 14 of its service area. Each mobile radio device 15 is equipped with a function that allows selective use of one of a large number of radio channels (referred to as multi-channel access).When communicating with the radio base station 13, the mobile radio device 1
5 communicates a control signal via the radio base station 13 to the radio line control station 12 which determines the use of radio channels of a large number of radio base stations 13, and determines the call channel number to be used for communication according to instructions from there. The system is configured to communicate with subscribers of the telephone network 10 via an exchange 11 including a switch SW.

Furthermore, in wireless communication, transmitting/receiving diversity is a commonly used technique. The same signal is transmitted at the same time from multiple transmitters with different frequencies at the transmission point,
If multiple receivers are tuned to the transmission frequency at distant reception points and then added together after detection, it becomes frequency diversity, or the transmission output obtained from one transmitter at the transmission point. Transmission space diversity is a method of dividing the signal and coupling it to 6Q m transmitting antennas at different locations for transmission, and then guiding it to the receiver using one antenna at a distant reception point to obtain the detection output. It is called. Furthermore, at the transmitting point, the output of the transmitter is guided to one antenna for transmission, and at the receiving point, which is separated by a distance, multiple antennas are installed in different locations and each is guided to the receiver. The method of stacking the waves or adding them after detection is called reception diversity.

In the above transmitting/receiving diversity, amplitude modulation and angle modulation are used to modulate the signal.

[Problem to be Solved by the Invention] In this case, if the number of radio channels provided to a certain radio base station for calls is 10, the number of radio channels provided to a certain radio base station for calls is 10, Since it is possible to allocate separate wireless channels to communication requests, it is possible to make calls without causing wireless interference, but the call request from the mobile wireless device that made the 11th request Because there was no wireless channel to allocate, calls could not be made (calls were lost). This was an example when a wireless channel is used to transmit an analog signal, but even when audio is digitally modulated, a single
Single Channel
Even in a system in which one telephone (communication) signal is carried and transmitted on one carrier wave, the above-mentioned unresolved problem remains.

Furthermore, if the allocated radio channel is used, the bandwidth of the signal is fixed, and a signal having a wider bandwidth than this bandwidth cannot be transmitted, which is a problem to be solved.

[Means for Solving the Problem 1: A plurality of radio base stations each having a radio transceiver, a radio reception circuit having a reception mixer that communicates while moving within a service area covered by the plurality of radio base stations, A wireless transmitting circuit having a transmitting mixer, a switching receiving means including a synthesizer capable of applying two frequencies to the receiving mixer of the wireless receiving circuit to switch and receive signals of two channels, and a transmitting mixer of the wireless transmitting circuit. A mobile radio device that includes a switching transmission means including a synthesizer that can switch and transmit signals of two channels by applying two frequencies; It is stored in a storage circuit, and when read out, it is read out in a predetermined time slot at a speed n times faster than the speed at which it is stored in the storage circuit, and the carrier wave is angle-modulated or amplitude-modulated with the signal accommodated by this time slot. , a radio reception circuit having reception mixers facing each other and communicating, which are built into a mobile radio device and a radio base station for time-intermittent transmission and reception;
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. A method is used in which the intermittent state is synchronized in both transmission and reception, and the same intermittent transmission and reception as described above is synchronized with that of the radio base station for the mobile radio device that communicates oppositely, and the reception side is accommodated in the predetermined time slot. In order to extract only the signals that are received, the wireless reception circuit is opened and closed to receive
The demodulated) q signal is stored in a storage circuit, and when read out, it is read out at a low speed of 1/n of the speed at which it is stored in this storage circuit.
By providing a communication path control unit means for setting a communication path with a predetermined mobile radio device using a slot, it is possible to reproduce the baseband signal, which is the original signal transmitted, at the radio base station and the mobile radio device. We built a system that includes a barrier switch to connect the general telephone network and wireless base stations.

As a result, even if all wireless channels given to the system are in use, if there is an empty slot that is not used for communication within each time slot of each wireless channel, a new call cannot be initiated. It is now possible to make a call to a mobile radio that has requested a call, it is also possible to continue a call to a mobile radio that has moved during a call from an adjacent zone, and it is also possible to call a mobile radio that has moved from an adjacent zone during a call. It has become possible for a mobile radio device in communication to perform diversity communication with other nearby radio base stations. When transmission of a wideband signal is required, it has become possible to easily transmit a wideband signal by using the necessary number of time slots if there are empty time slots.

In addition, by understanding and monitoring the call traffic within the serviceable zone of each wireless base station at the barrier switch, if the call traffic within a particular wireless base station is congested, it is possible to Traffic congestion can now be alleviated by temporarily allocating time slots assigned to stations to specific wireless base stations. In this way, it has become possible to realize a system with a high degree of effective frequency utilization.

[Operation] A radio base station and a large number of mobile radio devices exist within its service area, and in order for any number of mobile radio devices to be able to communicate with the radio base station, one radio channel is The minutes are divided into multiple time slot series by 3+1,
A system has been constructed in which one of these time slot sequences 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.

Furthermore, communication quality can be maintained while one radio base station and mobile radio are communicating using one time slot in one channel (one time slot in the old channel). In order to improve communication quality, one time slot (one time slot of a new channel) within the same or another channel is set up between another wireless base station that satisfies a certain communication quality. I used it to communicate. In addition, the gateway switch has an interface function for connection with other telephone networks and a control function for the mobile radio communication network, including determining the radio channel and its time slot used by the radio base station for communication with mobile radio equipment, Equipped with a function to stop emitting radio waves, etc.

This makes it possible to assign multiple time slots to terminal devices that use broadband signals within the permissible range of call traffic, and to transmit signals to wireless base stations around the area of call traffic when there is a congestion of call traffic. Allotted time
The service functionality of the mobile communication system has been improved by temporarily assigning slots to radio base stations in charge of congested areas to alleviate call traffic congestion.

[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 Ito's "Proposal of a Mobile Telephone System - An Approach to Ultimate Communication" IEICE Technical Report C386-88 November 1986, etc. It is assumed that a so-called microcell is used in which the size difference of each zone is extremely small, within 1KIn, as shown in FIG. In this case, each radio zone has a large overlap, and one radio zone is simultaneously serving as another radio zone.

In FIG. 1A, 10 is a general telephone network, 11 is an exchange on the telephone network 10 side, and 20 is a gateway exchange for connecting the exchange 11 and the wireless system. The gateway switch 20 controls a plurality of wireless base stations 30 and many mobile wireless devices in order to set up and release wireless lines and perform channel switching in conjunction with zone migration. Station 30-1.0 of 30-2 to 30-n
When each radio base station 30-1 to 30-n receives a transmission wave from a mobile radio, the communication control unit 21 controls the station, the ID identification unit 24 identifies the identification number of the mobile radio, and , an S/N monitoring unit 25 that monitors communication quality, and a communication system switching unit that is controlled by the communication control unit 21 to establish a connection between each of the wireless base stations 30-1 to 30-n and the exchange 11. A switch group 23 necessary for the above is included.

However, since the switch group 23 in FIG. 1A is simple, only three incoming lines from the exchange 11 are shown, and the wireless base station 30-
Communication signal 22-1-1.22-1 to 1 to 30-n
-2 to 22-1-m and 22-2-1.22-2-2
~22-2-m to 22-n-1, 22-n-2~2
The outgoing line for transmitting 2-nm is an nxm line.

The radio base station 30 includes a group of communication path switches that interface with the barrier exchange a20, a communication path control unit that controls the communication path, an ID identification storage unit, a circuit that performs speed conversion of signals, 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, between the barrier switch 20 and the wireless base station 30,
There are transmission lines for transmitting communication signals A22-1 to 22-m including communication signals of communication channels CHI to CHm 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 receiving circuit 135 including a receiving mixer 136 and a receiving section 137, and the output communication signals are sent to speed recovery circuits 138-1 and 138-2. It is input to the clock regenerator 141. The clock regenerator 141 regenerates the tarokk from the received signal and applies it to the speed restoration circuits 138-1, 138-2, the control section 140, the timing generator 142, and the speed conversion circuits 131-1, 131-2. are doing.

In the speed recovery circuits 138-1 and 138-2, in two time slots in the received signals of the two channels,
The speed of two communication signals each compressed and separated (
In the case of an analog signal, the pitch) is restored to obtain a continuous signal, which is mixed by a signal mixing circuit 152 and sent to the telephone unit 101, the speech quality monitoring unit 157. and is input into the ID information verification storage section 182.

The communication signal output from the telephone unit 101 is divided into two signals by a signal division circuit 139, and the communication signals are separated at predetermined time intervals by speed conversion circuits 131-1 and 131-2, and the speed ( In the case of an analog signal, the pitch) is set to high speed (compression), and the transmission mixer 133 and transmitter 1
34, and the transmission signal is sent out from the antenna section using two time slots and received by the plurality of wireless base stations 30. Speech quality monitoring unit 1 to which the output of the signal mixing circuit 152 is applied
At 57, the call quality during communication is constantly monitored, and when it deteriorates, it is reported to the control unit 140. The ID information collation storage unit 182 stores the ID (identification information) of the mobile radio device 100 itself.
It remembers things, and identifies and remembers which zone you are in.

The interference detector 162 monitors the presence or absence of interference during communication, and reports it to the control unit 140 if it detects interference of a certain value ω or more.

In this timing generator 142, the clock regenerator 14
1 and a control signal from the control section 140, the transmission/reception intermittent controller 123. Speed conversion circuit 131-1,
131-2 and speed restoration circuits 138-1 and 138-2 with necessary timing.

This mobile radio device 100 includes synthesizers 121-1 to 121-4 and selector switches 122-1, 122-4 to enable transmission and reception of roughly two channels at the same time.
2, and a transmission/reception intermittent controller 123 that generates signals for switching the changeover switches 122-1 and 122-2, respectively.
and a timing generator 142, which includes synthesizers 121-1 to 121-4 and a transmission/reception intermittent controller 12.
3 and the timing generator 142 are controlled by the control section 140. Each synthesizer 121-1 to 121
-4 is supplied with a reference frequency from the reference crystal excavator 120. With such a configuration, it is possible to communicate with a plurality of wireless base stations 30 using two channels.

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

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

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

m-channel communication signal 22-1 with barrier exchange R20
22-m are connected to the signal processing section 31 forming an interface through a transmission path.

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 to compensate for transmission loss, and also has two time slots.
In addition to the function for transmitting and receiving diversity using more than one wireless transmitter and the function for dividing the signal into multiple wireless transmitting and receiving units, if there are two relay lines between the gateway switch 20 and the gateway exchange 20, the so-called two-wire - A 4-line transformation is performed. That is, the input signal and the output signal are mixed and separated, and the input signal from the barrier switch 20 is sent to many switches 5WR1-1-1, 5WR.
1-1-2,..., SWRl-1-m, 5WR1-2
-1,3WR1-2-2゜-, SWRl-2-m, ・
, ・,5WR1-n-1,5WR1-n-2,-,S
SWR1 including WRl-n-m, 5WR2 including the same number of switches, and 5WT1-1-1, 5WT1
-1-2.・, SWTl-1-m, 5WT1-2-1
゜5WT1-2-2.・, SWTl -2-m-, ・
.

5WT1-n-1, SWTl-n-2, -, SWTl-
5WT1 containing n-m, 5 containing also many switches
A signal speed conversion circuit group 51-1 including many signal speed conversion circuits 51-1-1 to 51-1-m and a signal speed conversion circuit group 51- are connected via a switch group 83 configured to include the WT2. Sent to 2.

In addition, many signal speed restoration circuits 38-1-1 to 38-1-
The output signals from the signal restoring circuit group 38-1 and the signal speed restoring circuit group 38-2 including m are sent to the signal processing unit 31 via the switch group 83 and converted to the communication signal 22 using the same transmission path as the input signal. -1 to 22-m are transmitted to the barrier switch 20. Here, the switch group 83 includes transmission switches 5WT1° to 5WT2. and reception switch SWR1
, -5WR2, all of which operate under the control of the communication path control unit 81 to open and close the switch group 83 to achieve the desired purpose and to enable transmitting and receiving diversity.

I[1] The identification storage unit 82 is used to identify and store the ID of the mobile radio device 100. In addition, the communication path control section 81
The control unit 40 controls the communication path by opening and closing the switch u83 according to commands from the control unit 40, and also has the function of providing information and requesting control from the communication path control unit 81 to the control unit 40. Among the above, the input signal from the gateway exchange 20 passes through the switch group 83, and then passes through many signal speed conversion circuits 51-
Signal speed conversion circuit group 51= including 1-1 to 51-1-m
1 and the same <51-2, and undergo speed (pitch) conversion at predetermined time intervals.

In addition, the signals transmitted from the wireless base station 30 to the gateway exchange 20 are as follows:
The signals are inputted to the signal speed restoration circuit groups 38-1 and 38-2 via the signal selection circuit groups 39-1 and 39-2, and after being speed (pitch) converted, pass through the switch group 83.
The signal is input to the signal processing section 31.

Now, the control of the radio receiving circuits 35-1 and 35-2 or the output of the communication signal is performed by the signal selection circuit group 39-, which includes signal selection circuits 39-1-1 to 39-1-m that select signals for each time slot. 1 and 39-2, and here the speech signal is separated corresponding to the time slots included in the two radio channels received by each radio receiving circuit 35-1 and 35-2, for example, CH1 and CH2. Ru. This output is a signal speed restoration circuit 3 provided corresponding to each call signal.
Signal speed restoration circuit group 3 including 8-1-1 to 38-1-n
After the signal speed (pitch) is restored at 8-1 and 38-2, it is input to the signal processing section 31 via the switch group 83, and after undergoing 4-wire to 2-wire conversion, this output is sent to the barrier switch. 20 as communication signals Q22-1 to 22-n.

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 1XN100 shown in FIG. 1B-2.

Next, the functions of the signal speed conversion circuit groups 51-18 and 51-2 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.
ChargeCoupledDevice),
BBD (Bucket Brigade Device
), and the memory used in television receivers and tape recorders that compress or expand the time axis of conversation can be used (References: Koita et al. “Time axis of conversation ``A tape recorder that compresses and expands ``Nikkei Electronics, July 26, 1976, pp. 92-133).

The circuits using CCDs and BBDs exemplified in the signal speed conversion circuit groups 51-1 and 51-2 can also be used as they are in the signal speed restoration circuit groups 38-1 and 38-2, as described in the above literature. In this case, the reading speed is made slower than the writing speed by receiving a timing signal from a timing generator 42 that generates timing using a clock from a clock generator 41 and a control signal from a control unit 40. This can be achieved by

The control or call signal output from the barrier switch 20 via the signal processing section 31 is sent to the signal speed conversion circuit group 51-1.
．． and 51-2, and after being subjected to speed (pitch) conversion processing, it is applied to signal allocation circuit groups 52-1 and 52-2 that allocate signals for each time slot. This signal allocation circuit group 52-1, 52-2 is a buffer/
Memory circuit, signal speed conversion circuit U51-1.51
-2, each section of high-speed signals is stored in memory, and buffer?・
Reads the signal in the memory and transmits the wireless transmission circuit 32-1.3
2-2 respectively. This timing information is arranged chronologically in series with no overlap when viewed from the perspective of call signal correspondence, and may be necessary if the control signal or control signal and call signal described later are all implemented. It looks like a continuous signal wave.

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

The output signal of the signal rate conversion circuit group 51-1.51-2 is input to the signal assignment circuit group 52-1.52-2, and is necessarily assigned time slots in a predetermined order. SDl, SD2 in FIG. 2A(a). ..., SDn, the speed-converted communication signal is transmitted to the wireless transmission circuit 32-1.32-
2 (simply shown as 32) indicates that each time slot is allocated separately.

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 a call signal is not implemented, only the synchronization signal added by the call path control section 81 is used, and an empty slot signal is added to the call signal portion. In this way, as shown in FIG. 2A (a), the wireless transmission circuits 3:2-1.
32-2, time slots SD1-5Dr
A signal forming one frame at l is applied to the modulation circuit.

This time-series multiplexed signal is transmitted to the radio transmitting circuit 32-1
．． At 32-2, the signal is amplitude- or angle-modulated 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, you can use the low frequency side (250Hz) or the high frequency side (3850Hz).This signal can be used, for example, when you want to send a control signal during a call (for example, It is used when you want to apply zone switching or diversity during communication.

These control signals are generated in the control unit 40, as well as control signals from the barrier switch 20 and the communication path control unit 8.
The control signal from 1 is relayed or converted by the control unit 40 to be created and sent out.

The control signal sent from the mobile radio device 100 is received by the radio receiving circuit 35-1, 35-2, processed by the control unit 40, and sent to the communication path control unit 81 or the barrier exchange 1 as necessary.
120. - FIG. 3A (b) shows an example of in-band control signals, which are used when making and receiving calls.

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

The above was a case of analog signals, but if a digital data signal is used as a control signal, it is also possible to digitally encode the call signal and time-division multiplex the two to be transmitted. The circuit configuration of is shown in Figure 2E (
b).

FIG. 2E(b) shows a case where an analog audio signal is digitized by a digital encoding circuit 91, and this and a data signal are multiplex-converted by a multiplex conversion circuit 92, and then applied to a modulation circuit included in the wireless transmission circuit 32. This is an example.

Then, it is received by the opposite receiver, and the second E
If the operation is reversed to that shown in FIG. 3(b), it is possible to extract the call signal and the control signal separately.

On the other hand, the signal sent from the mobile radio IU 1100 is received by the antenna section of the radio base station 30, and is received by the radio receiving circuit 3.
5 (Input to 35-1 and 35-2>. 2nd A
Figure (b) schematically shows this upstream input signal. That is, time slot SU1. SU2.
−． Sun has mobile radios 100-1, 100-2.・
..., 100-n from the wireless base station 30 (for example, 30
-1> Indicates a transmitted signal addressed to. Also, each time slot S
U1゜SU2. ..., the details of the sun are as follows:
As shown in the lower left of FIG. 2A (b), it consists of a synchronization signal and a control signal or a call signal (and control signal). However, depending on the distance between the radio base station 30 and the mobile radio device 100 or the signal speed, the synchronization signal may be omitted. Roughly speaking, the waveform of the radio carrier wave of the above-mentioned uplink radio signal within a time slot is schematically shown as shown in FIG. 2B (C).

Of the input signals arriving at the radio base station 30, the control signal is immediately applied to the control unit 40 from the radio receiving circuits 35-1 and 35-2. However, depending on the size of the speed conversion rate, it is also possible to apply the output of the signal speed restoration circuit group 38-1, 38-2 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 39-1, 39-2.

A timing signal from a timing generation circuit 42 that generates a predetermined timing is applied to the signal selection circuit u39-1, 39-2 according to a control signal instruction from the control unit 40, and a timing signal is applied to each time slot SU1 to Sun. The synchronization signal, control signal, or call signal is separated and output. Each of these signals is input to the signal speed restoration circuit group 38=1, 38-2. This circuit is a speed conversion circuit 131-1, 131-2 (18th-
It has a function to perform the inverse conversion shown in FIG. 1), thereby faithfully reproducing the original signal and transmitting it to the gateway exchange 20.

The mode of transmission in the signal space provided by the present invention will be described below using the required transmission band and the relationship between this and adjacent wireless channels.

As shown in FIG. 1C, the control signal from the control section 40 is applied to the wireless transmission circuit 32-1.32-2 in parallel with the output of the signal allocation circuit group 52-1.52-2. However, depending on the size of the speed conversion rate, it is also possible to perform the same processing as the call signal and then add it to the wireless transmission circuit 32-1.32-2 from the output of the signal allocation circuit group 52-1.52-2. I'll go.

Next, in the mobile radio R100, as shown in FIG. 18-1, among the functions of the radio base station 30, when two call signals are transmitted using two time slots, the The circuit configuration is as follows. Original signal, for example, a telephone call signal (0.3KHz~3.OK+-12>
FIG. 3B shows the frequency distribution on the output side when the signal passes through the signal speed conversion circuit u51 (FIG. 1C). That is, if the audio signal is converted 15 times as described above, the frequency distribution of the signal will be 4.5 times as shown in Figure 3B.
5KHz~l15K)-12. The figure shows a case where the control signals are simultaneously transmitted using the lower frequency band of the call signal. Among these signals, the control signal (0.2~4°0KHz > and 1
Suppose that one speech signal (4,5 to 45Kl-1z and designated as SDl) is accommodated in a time slot, for example SDl. Other time slots SD2~
The same applies to the speech signal contained in SDn.

That is, time slot sDr <i=2°3,
, n) accommodates a control signal (0,2~4.0KH2>) and a communication signal CHi (4,5~45KH2). 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 32-1, 32-2 at the same time.

These call signals are sent to the wireless transmission circuit 32 along with control signals.
-1.32-2 When added to the angle modulation section included in
The required transmission band requires at least fo±45KHz. However, fo is the radio carrier frequency. If there are multiple wireless channels given to the system, the speedup of the signal by the signal speed conversion circuit group 51-1.51-2 is limited to a certain value due to the limitations of these frequency intervals. become. Let f be the frequency interval of a plurality of wireless channels, and let fH be the maximum signal speed due to the above-mentioned speeding up of the audio signal, then the following inequality must hold between the two.

f > 2 f H ep On the other hand, in digital signals, audio is usually 16 to 64 kb
Since the signal is digitized at a speed of about /S, it is necessary to raise the scale on the horizontal axis in Figure 3B, which explains the case of an analog signal, by about one digit to read it, but the relationship in the above equation holds true in this case as well. .

Further, the control signal input from the mobile radio device 100 to the radio base station 30 is input to the radio reception circuit 35-1. The signal is sent to the signal speed restoration circuit 138-1°38-2 via the signal selection circuit group 39-1°39-2. After the intruder's control signal undergoes speed conversion (conversion to a low speed signal) that is completely opposite to that at the time of transmission, it becomes the same signal speed as that used in the general telephone network 10 and is transmitted via the signal processing unit 31. and sent to Kanmon Exchange @20.

FIG. 1D shows another embodiment 100B of the mobile radio 100.
It is shown. Here, in front of the mobile radio 1 shown in FIG.
The difference from 00 is that two sets of wireless transmission circuits 132-1, 13
2-2 and two sets of radio receiving circuits 135-2, 135-
2 is provided, and synthesizer 1 is attached to these.
Transmit/receive intermittent controller 123 for outputs of 21-1 to 121-4
Switches 124-1 to 124-1 that are turned on and off under the control of B
24-4. The transmission/reception intermittent controller 123B opens and closes the switch switches 124-1 to 124-4 according to instructions from the control section 140B. With such a configuration, the mobile radio device 100B has no risk of radio interference, and can communicate with the same radio base station 30.
It has the advantage of being able to perform constant transmission and reception diversity.

FIG. 1E shows a first embodiment of the mobile radio device 100.
00C is shown. Here, the difference from the mobile radio device 100 shown in FIG. The switches 122-1 and 122-2, which operate under the control of the transmitter/receiver intermittent controller 123C, which operates according to instructions from the section 140, can transmit and receive signals in predetermined time slots, making it possible to implement transmitter-receiver diversity. .

Here, in order to simplify the configuration, there is only one set of speed restoration circuit 138 and speed conversion circuit 131, and signal mixing circuit 152 and signal division circuit 139 are not provided.

Next, the opening operation of the system according to the present invention will be explained in the following order, and the high practicality of the present invention will be theoretically proven. The explanation uses the case of a call signal as an example, and R'li2
describes non-telephone signals.

(1) Location registration (2) Call origination operation (3) Call reception operation (4> Channel switching operation during a call (5) Transmission/reception diversity performed between multiple wireless base stations (6) Diperity effect according to the present invention (7) Countermeasures for call traffic congestion in a specific wireless zone (8) Detailed explanation of the present invention (I > Adjacent radio channel interference (II > Self-channel interference (III) Co-channel interference (IV) Method for removing pulse noise when receiving signals (V) Effect of delay time of transmission signal (vl) Calculation of effective frequency utilization rate (9) Toward communication using non-telephone systems (wideband signals) other than telephone signals Application of the present invention (1) Location registration The mobile radio device 100 used in the present invention has various configurations as shown in Fig. 1B-1, Fig. 1B-2, Fig. 1D, and Fig. 1E. However, for convenience of explanation, the mobile radio device 1 shown in FIG.
The focus is on the location registration operation of 00C. Other mobile radio equipment 1
00 For example, in the case shown in FIGS. 1B-1 and 1B-2, if only synthesizers 121-1 and 121-3 are in operation and the other synthesizers 121-2 and 121-4 are in rest, then approximately 1E The configuration is as shown in the figure. Similarly, mobile radio F in Fig. 1D
In M100B, only the receiving section 135-1 and the transmitting section 132-1 are in operation, and the receiving section 135-2 and the transmitting section 132-2 are inactive.
8.100C is simply referred to as mobile radio device 100.

In the home area where the mobile radio device 100 is permanently located, or in the roam area which is an area within the service other than the home area, the gateway switch 20 and the surrounding radio base stations 30-1 to 30-p are already operating. When the power switch of the mobile radio 100 is turned on,
When the operation starts, the first thing that is performed is the location registration operation.

Prior to explaining the operation, a method of allocating radio channels to the radio base station 30 in a system to which the present invention is applied will be described. The following method is possible, and is exactly the same as the method currently used in analog systems.

(a) All radio channels can be used by each radio base station 30. (b) The radio channels that can be used by each radio base station 30 are allocated in consideration of the number of repeated zones in order to eliminate co-channel interference. (C) In addition to the distinctions in (a) and (b) above, the wireless channels given to the system are divided into control-only and call-only channels, and those that are not. (a), (b),
By combining (C), four types of systems are possible,
Furthermore, if we include the actual usage, an extremely large number of systems will be realized. The present invention is applicable to all of them.

However, in the following explanation, it is assumed that the following allocation method is used. In other words, all radio channels can be used by each radio base station 30, and no distinction is made between control and communication radio channels.

It is also assumed that the following methods are adopted to ensure smooth system operation.

i) All time slots within all radio channels transmitted from each radio base station 30 are synchronized by a synchronization signal supplied from the gateway exchange 20.

ii) Among the signals transmitted from the barrier switch 20 to the mobile radio device 100, when the signals are transmitted via different wireless base stations 30, the signal transmission timing, signal format, modulation depth, etc. All are the same.

However, other channel allocation methods and other methods for system operation will be added to the explanation as appropriate.

Furthermore, it is assumed that the following points are taken into consideration in the system design based on the radio wave propagation characteristics of the system to which the microcell is applied.

In other words, when the size of the zone becomes a small zone with a radius of less than 1 e, that is, it is called a microcell,
The radio wave propagation characteristics vary greatly depending on the location, and the service area of one wireless base station 30 is significantly different from a circular shape, and is an ellipse (ellipse) or a complex shape with unevenness. Therefore, each location in the service area is less likely to be covered by a single wireless zone, but instead becomes a dead area that is not included in any zone, or is covered by multiple wireless zones at the same time. In the former dead zone, communication is impossible, so in a real system there are more blanks than necessary to eliminate this dead zone. iii Ground station 3° will be installed. As a result, the overlapping of service zones is further promoted. In such a system, the mobile radio 100
However, if a location registration signal, which will be described later, is transmitted, it can be received satisfactorily by a plurality of wireless base stations 3 degrees.

The flow of the location registration operation under such system conditions is shown in FIGS. 4A and 4B and will be described.

When the power switch of the mobile radio device 100 is turned on, a location registration signal for registering the current location is sent to an empty time slot 5t in an uplink radio channel, for example, CI-11.
Using J1-1, select the nearest wireless base station, for example 30-
1.30-p (p=2.3°...) (8161, Fig. 4A).

This is possible by capturing the wireless channel C11 having an empty time slot 5D1-1 among the communication channels sent out from the nearest wireless base station 30-1, etc., obtaining timing information, and responding accordingly. Upstream radio channel CH1
This is because the empty time slot 5U1-1 is used.

In this case, as described above, the time slot 5DI-1 is an empty time slot even in the wireless base station 30-1. This is clear from the implementation of Career Sense.

In addition, in all radio base stations 30, all the receivers equipped therein are in a waiting state to receive signals within all time slots of a determined radio channel.
Upon receiving the location registration signal from 00 (Sl 62.S
l63) Many radio base stations 30-1, 30-p inspect reception quality and store the ID in the ID identification storage unit 82 (S164.3165>. As a result of inspecting reception quality, if the reception quality is above a certain value) In some cases (S166YES, 516
7YES>, the gateway exchange 20 sends a location registration request signal to the mobile radio device 20 (3168.8169>. Upon receiving this location registration request signal (S170), the gateway exchange 20 requests location registration of the mobile radio device 100. Create a table of IDs, received signal quality, etc. of all wireless base stations 30-1.30-p, and
It is determined to notify the mobile radio device 100 of the radio channel number (CHl in this case) and the transmission timing (3171, Fig. 4B). Channel CH1 time
Slot 5D1-1. Same <5 for wireless base station 30-2
DI-2,... Similarly, the same <5D1 for 3Q-n
-n.

These are included in the registration completion signal, and each wireless base station 3
0-1. It is sent to ao-p (S172). In the radio base station 30-1.30-p that received this registration completion signal (Sl 73.Sl 74), the downlink radio channel CH
1 time slot 5D1-1, 5D1-p (p=
2.3. ) to the mobile radio device 100 (3176.3177).

The registration completion signal transmitted in the time slot specified by the barrier switch 20 in this way is transmitted to the mobile radio device 100.
Good reception with no wireless interference.

After receiving this registration completion signal (S177), the mobile radio device 100 inspects the received content and identifies the ID (identification number) of each registered radio base station 30-1.3O-1).
The information is stored in the information verification storage unit 182 (317B>).

With the above operations, the location registration operation is completed and the device enters a standby state for an incoming call.

Next, it is assumed that the mobile radio device 100 moves from the zone in which its location has been registered while it is on standby (not making a call) and moves to an adjacent zone. The recognition of this movement is based on the wireless base 7430-
Each time of the wireless channel that is constantly transmitted from the 1st class
Wireless base station 30- in the control signal included in the slot
This can be determined by comparing the ID of No. 1 with the ID stored in the mobile radio device 100.

The radio channel constantly transmitted from the radio base station 30-1 etc. in above) may be a radio channel exclusively for control, or may be a radio channel transmitted for communication with another third party. In the case of a smart user, each time slot includes the ID of the wireless base station 30, and this will be verified.

In addition, in a system in which signals are not always transmitted from the wireless base station 30-1, etc., the mobile wireless device 100 transmits a location registration confirmation signal at fixed time intervals, and the wireless base station 30 that receives the signal It is possible to confirm the ID of the wireless base station 30 from the transmitted signal.

As a result, the wireless base station 1q has an I of 30-1, for example.
If it is discovered that the D information is new base station ID information that is different from the base station ID information previously stored in the mobile radio FM 100, the mobile radio FM 100 determines that it has moved to a new zone, The control unit 140 (see FIG. 1B-1) updates the location registration in the ID information verification storage unit 182.

That is, the ID information of the mobile radio device 100 is transmitted to the radio base station to which the received signal is sent, for example 30-2, using an uplink radio channel having an empty time slot.

The wireless base station 30-2 that successfully received this signal performs the same procedure as already explained, and
The location registration signal of the mobile radio device 100 is sent to the mobile radio device 100. Upon receiving this signal, the gateway switch 20 operates the ID identification storage section 24 in its own device, rewrites the old information to new information as the location registration information of the mobile radio 100, and moves from the radio base station 30-2. The wireless device 100 is notified of this fact.

As a result, the location registration of the mobile radio device 100 is updated.

The above update work is necessary because the mobile radio device 100 is in standby mode, and when moving to a new zone during communication (talking), a new front channel is assigned to the barrier switch 20 as will be described later. A new front-line base station 30-2 and a mobile radio device 10
0, the location registration is updated at the same time, so no special operation is required.

In the above explanation, the mobile radio device 100 having the configuration shown in FIG. 1E is used. The mobile radio devices 100 and 100B shown in FIG. 1B-1 and FIG. 1D have been described assuming that some of their functions are inactive. In an actual system, there is no need to suspend the function; rather, it is desirable to actively utilize it. In other words, when this function is activated, the mobile radio device 100C shown in FIG.
You will be able to demonstrate excellent abilities such as those shown below.

i) Diversity transmission becomes possible, and location registration request signals can be sent simultaneously using two different radio channels.

ii) Diversity reception becomes possible, and signals on different radio channels from the same or two different radio base stations 30 can be received simultaneously.

1ii) From i) and ii), it is possible to improve the reliability of the control signal and speed up the registration operation.

(2) Calling operation will be explained using the flowcharts shown in FIGS. 58 to 5C.

When the mobile radio device 100 is powered on, it is already (1
) The location registration operation described in the location registration section has been completed.

Therefore, when the handset of the telephone base 101 is off-hook (starting a call) (S201, FIG. 5), an empty time slot 5U1- n is found, and using this, a calling signal is transmitted to the nearby wireless base station 30-1, 30-2. That is, to explain the operation of the mobile radio device 100, first, reception is possible by capturing a synchronization signal within the time slot SDi shown in FIG. 2A (a). The control unit 140 sends a control signal to the synthesizer 121-1 to generate a local frequency that enables reception of 1.1 on wireless channel C, and the switch 122-1 also controls the synthesizer 121-1 side. It is turned on and fixed.

Furthermore, the synthesizer 121-3 in FIG. 1E receives from the control unit 140 a control signal that generates a local frequency that enables transmission of the wireless channel CH1. Further, the speed restoration circuit 138 is in an operating state, and the speed restoration circuit 138
-2 is assumed to be in a dormant state.

Further, the switch 122-2 also turns on the synthesizer 121-3 side and becomes fixed. Next, wireless channel V channel C
The calling control signal output from the telephone unit 101 is sent using H1. Further, it is assumed that the speed conversion circuit 131 is in an operating state.

Now, the above-mentioned control signal can be divided into, for example, the time slot Sun according to the frequency band shown in FIG.
Sent using

The control signal included in the time slot Sun is:
For example, it contains:

i) ID of the mobile radio device 100 itself.

■) ID of the wireless base station 30 whose location is registered.

iii) ID0 of the called party; iv) Radio channel number and time slot number in use.

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

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

Roughly speaking, this control signal includes control information such as the currently used time slot and unused time slots 1 to 1 (empty time slot display). Depending on the system, time slot soi = 1.2°...
n) may only contain synchronization and speech signals when they are being used by other communications; By receiving this control signal, the mobile radio ta100 can know which time slot should be used 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, no radio waves are transmitted to empty time slots or no empty slots are displayed in any of the time slots, and in this case, the following audio multiplex signal SDI, SD2.・
..., it is necessary to search for the presence or absence of SDn one after another and check for empty time slots.

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

Therefore, assuming that the time slot Sun for uplink signals is an empty slot, it is decided to use this empty time slot, and the necessary timing is determined from the response signal from the radio base station 30 by sending out a control signal for calling. It is also possible to send out burst-like control signals.

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

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

Now, the call control signal from the mobile radio device 100 is sent to a plurality of nearby radio base stations 30-1, 30-2°..., 3
0-n, etc., and when the ID (identification number) of the mobile radio 100 is detected (3202, 3203), even if the ID of the mobile radio 1100 is unregistered,
It memorizes at that point and sends a calling signal to the gateway exchange 120 (S204゜5205>.Sends a calling signal to the gateway exchange 20 in the same way as the already registered wireless base station 30.

Since the barrier switch 20 receives similar signals from a plurality of wireless base stations 30-2 and the like in addition to the wireless base station 30-1, it selects a wireless base station 30 suitable for communicating with the mobile wireless device 100. The decision is made after comprehensively examining the traffic conditions, reception quality, etc. in that zone. As a result, if the wireless base station to be used for communication is determined to be 30-1, 30-2, the wireless channel to be used for communication is determined to be CH1, and the time slots are determined to be 1 and 2, respectively (S206>, this is determined to be 30-1 and 30-2, respectively. 1. Contact 30-2 (S207)
. Other radio base stations 30 are notified of the inability to communicate, or timeout occurs without sending any signals.

Now, the radio base station 30-1.3 that received the communication command signal
In 0-2 (3208, 3209>, preparations are made to receive on the designated radio channel and time slot, respectively, and radio channel CH1 and time slot 5 are respectively received.
To the mobile radio device 100 using D1-n, the barrier exchange is 20
Convey the instructions of the person (S210, 5211, Figure 5B)
. In mobile radio 100, this signal is transmitted to radio base station 30-
Since they are transmitted from 1°30-2 at the same time and with the same signal content, there is no risk of radio interference and they are received well.

In response, the mobile radio device 100 shifts to a state in which it can receive data in the two instructed time slots 5DI-1 and 5D1-2, and also in the downlink time slot 5.
5U1-1 and 5U1-2 are time slots for two uplink radio channels corresponding to D1-1 and 5D1-2.
(See FIG. 2A(b)). At this time, in the control unit 140 of the mobile radio device 100, the transmission/reception intermittent controller 123 is operated, and the switches 122-1 and 122
-2 starts operation (3212>. At the same time, a slot switching completion report is sent to each upstream time slot 5.
Wireless base 830-1.3 using U1-1,5UI-2
0-2 and wait for dial tone (3213>
.

Time slot 5U of the radio carrier wave of this upstream radio signal
The state of 1-1 etc. is schematically shown in FIG. 2B (C). The wireless base station 30 has time slot 5LJ.
In addition to 1-1 and 5U1-2, 5U1-3 and 5U1-n are included in one frame and sent as uplink signals from the mobile radio device 100.

Radio base station 30-1 that received the slot switching completion report.
30-2 sends a calling signal to the barrier switch 20 (3214.3215), and the barrier switch 20 that receives the call signal
Then, detect ■D of the mobile radio 100, and perform the barrier exchange 120.
Turns on the necessary switch among the switch group included in (8216) and sends out a dial tone (S2
17>.

This dial tone is the radio base station 30-1 and 3
0-2, and wirelessly transferred from the radio base stations 30-1 to 30-2 to the mobile radio 100 (8218.32
19>. In this transfer, the same signal contents instructed from the gateway exchange 20 are transmitted. Therefore, the mobile radio device 100 can obtain a time diversity reception effect and can receive signals well.

Now, as described above, the mobile radio device 100 confirms that the communication path has been set (3220). When this state is reached, a dial tone is heard from the handset of the telephone section 101 of the mobile radio device 100, and the transmission of a dial signal begins. This dial signal is speed-converted by a speed conversion circuit 131, and sent to an upstream time thrower 1 to 5U from a wireless transmission circuit 132 including a transmission section 134 and a transmission mixer 133.
1-1, 5U1-2 (S221, FIG. 5C).

Thus, the transmitted dial signal is sent to the wireless base station 30-
1.30-2 is received by the radio receiving circuit 35-1. This radio base station 30-1, 30-2 has already responded to the calling signal from the mobile radio 100,
As well as giving a slot, the wireless base station 30-1.30
-2 signal selection circuit group 39-1 and signal allocation circuit group 5
2-1 to operate uplink time slot SU1-
1, or 5U1-2, and is now in a state of transmitting the signal of the correct time slot SDI~1 or 5D1-2.

Further, the communication path control section 81 selects the switch 5WR for reception among the switch group 83 according to the control signal from the control section 40.
1-1-1, or 1-1-2, and a switch 5WT1-1-1 for transmission. Or turn on 1-1-2 (
The state shown in FIG. 1C) is set. Therefore, the dial signal transmitted from the mobile radio 100 passes through the signal selection circuit 39-1-1 of the signal selection circuit group 39-1, and then passes through the signal speed restoration circuit 3 of the signal speed restoration circuit group 38-1.
8-11, the original transmission signal is restored here, and is transferred to the gateway exchange 20 as a call signal 22-1 via the signal processing unit 31 via the switch group 83 (8222,
3223), a call path to the telephone network 10 is set (S2
24>.

On the other hand, the input signal from the barrier exchange Ia 20 (initial control signal, call signal @ when the call starts) is sent to the wireless base station 30-
1.30-2, switch 5WT of switch group 83
1-1-1. Alternatively, after passing through 1-1-2, the signal speed conversion circuit 51-1-1 of the signal speed conversion circuit group 51-1 receives speed conversion, and then the signal allocation circuit 52 of the signal allocation circuit group 52-1 receives the speed conversion. -1-1 to time slot 5D1-1
．． 3D1-2 is given. and wireless transmitter circuit 3
Time slot 5D1- of the radio channel downstream from 2
1. Alternatively, the mobile radio device 100 may be
sent to. In the mobile radio 100, time slots 5D1-1 . Or, the wireless receiving circuit 1 is waiting for reception in 5D1-2.
35 and its output is input to the speed recovery circuit 138. In this circuit, the original signal for transmission is restored and input to the receiver of the telephone unit 101 via the signal mixing circuit 152. Thus, a call is started between the mobile radio m''+oo and a regular telephone within the regular telephone network 10 (S225).

The call is terminated by on-hooking the handset of the telephone unit 101 of the mobile radio device 100 (S226>, the end-of-call signal and the on-hook signal from the control unit 140 are transmitted to the speed conversion circuit 1.
31 from the wireless transmission circuit 132 to the wireless base #30-
1.30-2 (8227>, the control unit 140 stops the operation of the transmission/reception intermittent controller 123, and switches 122-1 and 122-2 to synthesizers 121-1 and 121-2, respectively. Fix it to the output end of the

On the other hand, when the control unit 40 of the wireless base station 30-1, 30-2 receives the call termination signal from the pre-movement 4a machine 100, it transfers the call termination signal to the barrier switch 20, and switches 5WR1- of the switch group 83 1-1 or 1-1-2,5WT1
-1-1 or 1-1-2 is turned off to end the call (S228.5229). At the same time, radio base station 30-1.
The signal selection circuit group 39 (39-1) and the signal assignment circuit group 52 (52-1> in 30-2 are opened.The barrier switch 20 that receives this call termination signal turns off the switch group 23. (3230) In the above explanation, control signals are exchanged between the radio base station 30-1. or 30-2 and the mobile radio device 100 using the signal speed conversion circuit group 51-1. 38-1, etc., but this is for the convenience of explanation, and like the call signal, even if it passes through the signal speed conversion circuit group 51-L signal speed restoration circuit group 38-1 or the signal processing section 31, Communication can be carried out without any problems.

(3) Call Receiving Operation The call receiving operation to the mobile radio 100 will be explained using the flowcharts shown in FIGS. 68 to 6D.

It is assumed that the mobile radio device 100 is on standby with the power turned on. In this case, the mobile radio device 100 has already completed location registration and is in a state of waiting for incoming calls except when making a call itself. In this state, the mobile radio tU 1100 is waiting for a signal transmitted from the nearby radio base station 30, but depending on the system, there are various cases as follows.

i) When there is a dedicated radio channel for control In this case, according to the instructions of the control signal included in each time slot of the control channel, if there are multiple control channels,
Instructions are given, such as which control channel should be used for standby, or even in the case of one channel, which time slot should be used for standby, and mobile radio 100 follows these instructions to standby. Note that the above instructions are given by the wireless base station 30 or the barrier exchange 20.

ii) When the radio channel does not have a control or call division In this case, the system will meet at an empty time slot in a certain call channel in accordance with the method determined by the system. Specifically, for example, the following method is used.

If the wireless base station 30 has one wireless channel,
In a system that only has channels, it searches for an empty time slot and waits in a time slot (eg, 5D1-1) that follows the instructions of the control signal contained therein. Also, unless otherwise instructed, the samurai will be served in the lower numbered time slot.

Next, a plurality of radio channels are provided to the system, and the radio transmitting circuits 32-1, 32-2, . ...
32-n (only 32-2 is shown in FIG. 1C due to space limitations) are downlink radio channels C)-11 (frequency F1>, Cl-12 (frequency "2"), ..., CH
n (frequency F0), and the wireless receiving circuit 35
-1.35-2. ..., 35-n (only up to 35-2 is shown in FIG. 1C due to space constraints) corresponds to the uplink radio channel C1-11 (frequency f1>, CH2 (
Frequency f2),...

CHn (frequency f.), i) a specific free time slot of the radio channel indicated by a control signal included in the radio channel; 30 from free time slots of all radio channels, either constantly or intermittently.

:1) The wireless channel (hereinafter referred to as channel CH1) of the wireless channel with the lower number transmitted from the wireless base station 30 and the empty time slot of the lower number, etc. according to the procedure defined in each system. It is in the receiving state. This is possible by capturing the synchronization signal within the time slot SDi shown in FIG. 2A(a). For example, CHl selects the channel to be waited on among the radio channels transmitted from the radio base station 30.
, time slot 5DI-1, the control unit 140
Then, a control signal is sent to the synthesizer 121-1 to generate a local oscillation frequency that enables reception of the wireless channel CHI, and the switch 122-1 is also kept in a fixed state with the synthesizer 121-1 side turned on. .

iii) At the gateway switch 20 and the wireless base station 30,
Instead of giving the above instructions, when a call arrives, the call signal is transmitted all at once using the free time slots of all wireless channels. Although this method is somewhat disadvantageous in terms of effective frequency use, it enables inexpensive and highly reliable signal transmission.

Under the above conditions, the mobile radio device 100 is sent from the general telephone network 10 to the gateway exchange FA 20 via the exchange 11.
Suppose there is an incoming call addressed to the user. When the gateway exchange 20 searches the ID identification storage unit 24, it recognizes that the mobile radio device 100 is currently registered in its location with the radio base stations 30-1 and 30-2. Prepare to send the signal. That is, the traffic within the radio base station 30 that is in charge of communication.

Determine by considering signal quality etc. at the time of location registration. As a result, when the radio base station 30-1 and 30-2 is determined to be in charge of communication, the radio base station 30- 1. An incoming call signal is sent to 1°30-2 (S251, FIG. 6A).

This signal is transmitted to the radio base station 30-1.30-2 as communication signals 22-1 to 22-m through the switch group 83 to the signal speed conversion circuit group 51-1.51-2, similar to the call signal.
and is transmitted to the control section 40 (FIG. 1C) via the signal assignment circuit groups 52-1 and 52-2.

Then, the control unit 40 instructs the communication path control unit 81 to send and receive switches SWT and S of the switch group 83.
Check the switch that can be used as WR and instruct it to be kept in the on state.

Further, the signal is transferred to the mobile radio 1100 in the method instructed by the gateway exchange 20 (S252゜5253>).

This method includes, for example, wireless base stations 30-1 and 30-2.
At the same time, the same wireless channel CH1° time slot 5D1-1 is used to transmit the same signal. The same signal means, for example, the I of the mobile radio device 100.
There is a D signal tube incoming call signal display signal. The above explanation was mainly about the wireless base station 30-1, but the same <30
A similar operation is performed at -2.

Mobile radio device 100 receives this signal and transmits it from receiving section 137 of radio receiving circuit 135 to control section 140 . In the control unit 140, this signal is transmitted to the own mobile radio device 10.
Since it is confirmed that it is an incoming call signal to 0 (S254)
, time slots 5U1-1 . . . for radio base stations 30-1 and 30-2, respectively. St, 11-2 is used to send back the ID of the mobile radio device 100 as a response confirmation signal (S255>.

Now, the radio base station 30-1, 30-2 that received the incoming call response signal from the mobile radio device 100 confirms the ID, performs a quality check (S256, 8257), and sends the data along with these data to the gateway switch 20. Send an incoming call response signal (32
58.3259>.

By the way, the incoming call response signal from the mobile radio device 100 may be received not only by the radio base stations 30-1 and 30-2 but also by other nearby radio base stations 30-3 and the like. Alternatively, if the mobile radio device 100 does not update the location registration for some reason after completing the location registration, the radio base station 30-1. There are cases where the base station 30 etc. can receive the signal well. That is, the surrounding radio base station 30 constantly monitors the available time slots of each radio channel, and if a call is made from the mobile radio device 100,
Alternatively, if the incoming call signal is successfully received, the system is designed to take necessary measures immediately. As one of these measures, in the case of the above-mentioned incoming call response signal, this is notified to the barrier exchange 20.

Due to the system operation described above, the incoming call response signal to the barrier switch 20 may include the ID of the unregistered radio base station 30 in addition to the ID of the mobile radio 50.

When this incoming call response signal is received, the gateway switch 20 stores the ID of the mobile radio 100 in the ID identification storage unit 2.
If it is not stored, it is registered in the ID identification storage unit 24 along with the quality inspection data of the wireless base station 30, and the location registration signal is stored together with the stored ID. It will be transmitted to the wireless base station 30-3 and the like. The subsequent operations are the same as for the location-registered wireless base stations 30-1 and 30-2.

Now, returning to the main topic, the gateway exchange 20 that has received call response signals from multiple wireless base stations 30 confirms the ID (S260>) and then determines the wireless base station 30 to be communicated with, the wireless channel to be used, the time slot, etc. and commands to radio base stations 30-1 and 30-2 respectively (3261, 6th B
figure).

The radio base station 30-1, etc. that received this signal confirms that the ID of the mobile radio device 100 has been correctly registered (
5262, 3263>, please check whether the channel time slot specified from the barrier exchange 1% tFII20 is vacant and consider whether or not to switch. 5264.526
5>, the resulting channel time slot designation signal is transmitted to the downlink channel V channel CHI, time slot 5.
Sends to mobile radio device 100 via DI-1 (S266
．． 3267).

This channel time slot designation signal was received (
3268>, the mobile radio 100 receives the time and
If it is confirmed that the slot is an empty channel (3269>), it switches to the time slot of that channel and sends a channel/time slot switching completion report using uplink radio channel CH1゜time slot 5UI-1. The response to the designated signal to the time thrower 1 sent from another radio base station 30 is the same as above.

Verified that it was switched to a free time slot (
S271.5272) The radio base station 30-1 etc. switches its own transmission and reception to this channel time slot, and sends a channel time slot switching completion signal to the barrier exchange R20 (S273, 5274> .

When the gateway switch 20 receives the channel/time/slot switching completion signal, it operates two call path control units to set the call path to the telephone network 10 via the switch 11, and switches the switch group 23 appropriately. The switch SW is turned on to connect the wireless base station 30-1, 30-2 and the telephone network 10 (S275). Therefore, from the telephone network 10 side, switch 1
1 and barrier exchange, a calling signal is sent through 20 (
3276>, this is confirmed at the wireless base station 30-1.
3279, 3280)
, the mobile radio 100 generates a ringing tone (3281>).

When the handset on the mobile radio 1oo side is lifted (off hook) by this ringing tone (8282, Fig. 6D)
, channel CH1, time slot 5LJ1-1,5
An off-hook signal is sent by U1-2, and the wireless base station 3
Transferred at 0-1.30-2 (3283, 3284)
, is received by the gateway exchange 20 (S285>, the switch 5W1-1-1.2-1-1 of the switch group 23 is on, and the communication channel is not established between the mobile radio device 100 and the radio base station 30-1. CH1, time slot 5D1-1.
5UI-1, down frequency F1, up frequency @f1, communication channel Cl-11 between mobile radio device 100 and radio base station 30-2, time slots 5D1-2, 5U1
-2. Downlink frequency F1.

Using the uplink frequency f1, the telephone network 10 and the mobile radio device 10
0 (3286>).

When the call ends, the handset is put down and the on-hook signal and end-of-call signal are sent to channels CH1, 5U1-1, 5U1.
-2 to the wireless base station 30-1.

30-2 (3287>), and the wireless base stations 30-1 and 30-2, which have confirmed the end of the call, transfer this signal (S
288.3289>. Upon receiving this on-hook signal and call-end signal, the barrier switch 20 operates the communication control section 21 and switches the switch S that has been used up to now in the switch group 23.
Turn off W and end the call (3290>.

In the above description, the wireless channels used by the wireless base stations 30-1 and 30-2 are the same channel CH1, but this does not necessarily have to be the same. Depending on the system, the same wireless channel in adjacent zones may not be available. Assuming this case, channel CI-(1 and C
It may be set to H2.

However, in this case, the synthesizer 121 in FIG.
-1 and 121-3, it is necessary to generate the local oscillation frequencies of channels CH1 and CH2 at a predetermined timing, and fast response performance is required. On this point, the first
The configurations shown in FIG. B and FIG. 1D facilitate operation.

(4) Channel switching operation during a call When the mobile radio 100 moves as a car or a pedestrian moves,
The operation when switching the call (communication) channel to communicate with the radio base station 30-3 while communicating with the radio base stations 30 to 1 and 30-2 will be described. In addition, the feature of the present invention, which is that there is no instantaneous interruption due to channel switching, will also be explained.

The mobile radio device 100 uses the synthesizer 121-1, the radio receiving circuit 135, and the radio transmitting circuit 132 to communicate with the radio base station 30-1. 2 and down 5
It is assumed that communication is in progress using DI-1, 5DI-2. The mobile radio device 100 moves away from the radio base station 30-1,
Assume that you approach the wireless base station 30-3. Then, as the relative distance between the mobile radio device 100 and the radio base station G130-1 increases, the call quality begins to deteriorate. The quality deterioration of the transmission signal from the machine 100
/N Monitoring unit 25 (confirms that the level has fallen below 11)
To detect. Note that even at level 11, the line is set to exceed the required value. All nearby wireless base stations 30 are requested to measure the quality of the transmitted signal from the mobile wireless device 100.

In response to this request, each radio base station 30 sends the measured value to the barrier exchange R20, so the S/N monitoring unit 25 of the barrier exchange IE 120 starts comparing it with level 1-2 of the communication quality standard. As a result of the comparison, if it is confirmed that the measurement result of the base station 30-2 has the best value and satisfies the quality standard level 2 or higher, but L2>Ll, then the mobile radio has a value of 100. determines that the mobile station has moved to the communication zone (zone 3) of wireless base station 30-3, and decides to perform channel switching. Then, as a result of investigating communication channels having vacant time slots in zone 3, it is learned that wireless channel Cl-11 is usable. Therefore, using the time slot 5D1-1.5U1-1 of the downlink radio channel 17 CH1 currently in use, a control signal is sent to the mobile radio 100 to transmit the radio channel CH1.
For example, it instructs to prepare for transmission and reception in time slot 5D1-3.5U1-3.

At the same time, time slot 5D1-2.5U2-2 of wireless channel CH1 is transmitted to wireless base station 30-3.
Instructs to send and receive data using .

After issuing these instructions, the barrier switch 20 switches the switches 5W1-1-1, 2-1-1 and 5W of the switch group 23.
3-1-1 is turned on at the same time, and the wireless base station 30
-3 also starts transmitting the same call signal as that for radio base stations 30-1 and 30-2. Also, of course 3
It is assumed that the modulation depth of the modulators of the two radio base stations 30-1, 30-2, and 30-3, the length of time slots, the number within one frame, the timing of each radio channel, etc. are the same.

In order to realize the transmission of this control signal, specifically, in the case of a control signal or an analog signal, as shown in FIG. f.0 (e.g. about 100H2> or high frequency f , f , f[) I D2 D3 ... f, 8 (e.g. 3.8KHz to 0.1KHz
8 waves up to 4.5KI-1z at intervals) are used.

When there are many control items, ie, control data, the wave numbers of the control frequencies f, o to fD8 may be increased roughly, or a subcarrier format may be used. At this time, for example, f. By applying frequency modulation or amplitude modulation to one or more waves of ~f08, more control data can be transmitted.

Furthermore, when a digital data signal is used as a control signal, it is also possible to digitally encode the audio signal and time-division multiplex the two to be transmitted.
This is shown in Figure E (b). FIG. 2E(b) shows an example of a case where an audio signal is digitized by a digital encoding circuit 91, and the audio signal is multiplexed with a data signal by a multiplex conversion circuit 92, and then applied to the modulation circuit of the transmitter 31.

FIGS. 2C and 2D show timing charts before and after channel switching in the present system shown in FIGS. 18 to 1D.

In FIG. 2C (C) or (d), the downlink time slot 5D1-1 or 5D2-2 is used by the radio base station 30-1 or 30-2 as a transmission signal addressed to the mobile radio device 100, respectively. Time slot of radio channel CI-11; other time slots are used for other mobile radios (including empty slots)
shall be. Similarly, in FIG. 2C (e), time slot 5D3-3 is the time slot of radio channel CH1 that radio base station 30-3 with which new communication is to be performed uses as a transmission signal addressed to mobile radio device 100. Suppose it is a slot.

Furthermore, (f>, (g>, and h) in FIG. 2D are transmitted from the opposing mobile radio device 100 after receiving the outputs of (C), (d), and (e) in FIG. 2C, respectively. Therefore, the time slots used are 5U1-1 (C1l) and 5U2-2 (CHl), respectively.
>, 5U3-3 (CHl'),
Others are used for other communication (including empty slots)
It is something.

In FIG. 2C (C) and FIG. 2D (f), time slot SD'L-1, 5U1 of channel C)-11 used between the radio base station 30-1 and the mobile radio device 100
The S/N monitoring unit 25 of the barrier switch 20 detects that the quality of -1 has decreased to 1 or less, and the
time thrower of I)~5U3-3 to wireless base station 30-
Using time slot 5D1-1 of channel C)-11, the mobile radio 100 is instructed to start preparing to be able to receive the transmitted radio waves from C)-3 in parallel.

Therefore, the control unit 140 of the mobile radio 100 uses only the synthesizer 121 until then to control the channel CH1.
time slot 5D1-1. And from the state in which 5D2-2 is receiving transmission waves from radio base stations 30-1 and 30-2, time slot 5D3-3 frequency F1 transmission of channel CH1 transmitted from radio base station 30-3 The synthesizer 121 is made to generate a frequency that makes it possible to receive waves as well.

Channel CH1 transmitted from the wireless base station 30-1
When the radio base station 30-3 emits a transmission wave in the time slot 5D3-3 of the channel CH1 due to the quality degradation in the time slot 5D1-1, the mobile radio 1
00, the transmission/reception intermittent controller 123 is activated to repeatedly switch the changeover switch 122-1. At the same time, only the synthesizer 121-1 has been operated until then, and the time slot 5tJ1-1 of the wireless channel CH1 is
．． Wireless base, 1i30-1°30 using 5U272
-2, time slot 5U3- of channel C1-11 is transmitted to radio base station 30-3.
3. The state is changed to a state in which transmission can be performed using the frequency f1. Synthesizer 121-1 used for this transmission
and 121-3 are also repeatedly switched by the signal from the transmission/reception intermittent controller 123 by the changeover switch 122-2.

Channel C11 time slot 5U1-1゜5U
This switching transmission/reception period during which 2-2 and 5U3-3 are transmitted and received in parallel is the time slot 5U of channel CH1.
Confirmation of 3-3 and level 2 with constant quality of the same channel
This continues until the gateway exchange 20 confirms that the above is true, and then the channel CH1 time slot 5D1-
Open 1.5U1-1 and connect wireless base station 30-2.30-
3 and the mobile radio 100(B) are conducted in time slots 5D2-2, 5D3-3, 5 of channel CH2.
It continues without momentary interruption only by U2-2, 5U3-3.

The switching frequency f1 of the changeover switch 122-1 or 122-2 during this switching transmission/reception period is a value determined for each system, and the number of time slots in one frame included in the wireless channel CH1 is n, 1. time·
If the time interval between slots is T1, it is given by f=(nT1).

FIGS. 78 to 7D are flow charts showing the flow of operations during channel switching during a call in the system shown in FIGS. 18 to 1D.

Gateway exchange 20. Wireless base station 30-1, 30-2.30
-3 and the mobile radio Ia 100 start operation, and the switch 5W1- of the switch group 23 included in the barrier switch 20
1-1.2-1-1 is on, and the wireless base station 30-1
．． Communication is in progress between 30-2 and mobile radio IQO.

This communication includes communication itl+ included in the barrier exchange 20.
+Wireless channel C1-1 instructed by control unit 21
1 time slot 5D11, 5D2-2, 5U1-
1.5U2-2. Both the downlink frequency F1 and the uplink frequency f1 are used (S101, FIG. 7A).

The radio base stations 30-1 and 30-2 that are in communication constantly send out a reception status report from the mobile station 100 (S1
02), the S/N monitoring unit 2 of the barrier switch 20 that received this
In step 5, it is monitored whether the call quality has deteriorated below level L1 (S103). Call quality is level L
1 (S103YES), the communication control unit 21 sends a message to the wireless base stations 30 in the vicinity of the wireless base station 30-1 to confirm that the communication between the wireless base station 30-1 and the mobile wireless device 100 is Instructs to monitor and receive the signal of up frequency f1 and time slot 5UI-1 used for communication (S104).

Each of the surrounding wireless base stations 30 (for example, 3O-3) that received the monitor reception instruction receives the frequency f1. The signal of time slot 5U1-1 is monitored and received (5105), and the result is reported to the S/N monitoring unit 22 of the barrier switch 20 (51).
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 30-3 is better than a certain standard level L2 and is the best (S107YES).

Therefore, the communication control unit 21 controls how the mobile radio device 100 moves from the zone covered by the radio base station 30-1 to the radio base station 30-3.
S'10 seems to have moved to the zone covered by
8, FIG. 7B), to search for a channel with an empty time slot that can be used by the radio base station 30-3 in order to switch to communication with the radio base station 30-3.
09), as a result, time slots 5D3-3 and 5U3-3 of channel CH1 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 HI time slots 5D3-3 and 5U3-3 (S111).

Time slot 5D3-3.5 of this channel CHI
The communication preparation command for using U3-3 is sent to the wireless base station 3.
0-3, time slot 5 of channel CH1
Prepare for communication by D3-3.5U3-3 (S11
2). This command is simultaneously sent from the wireless base station 30-1 in the time slot 5D1-1 of the channel CHI (3113). The mobile radio 100 uses this channel C
H1, time slot 5D3-3, 5U3-3, receive communication preparation command on frequency F1 5114), channel CH2, time slot 5D3-3, 5U3-3
Preparations are made to enable communication by V, and the state in which frequency F1 can be received and transmitted from the control unit 140 to synthesizers 121-1 and 121-2 continues. The controller 123 enters into operation using time slot 5D3-3.5U3-3 (S115, FIG. 7C).

Channel CI-11 time slot 5D3-3°5
When ready to communicate using U3-3, the mobile radio I
A100 reports the completion of preparation to the wireless base station 30-3 using time slot 5U3-3 of channel C1 (S116).

Upon receiving this report, the wireless base station 30-3 performs step 51.
Time slot 5D3-3.5U3- prepared in 12
3 confirms the completion of preparation within the wireless base station 30-3 and sends a report to the barrier switch 20 <3117).

When the barrier exchange 1a20 confirms the completion of communication preparation between the radio base station 30-3 and the mobile radio device 100 using the time slot 5D3-3.5U3-3 (3118)
, switch 5W1-1-1.2-1- of switch group 23
1 remains on, and the switch 5W3-1-1 is also turned on (S119). Therefore, the communication control unit 21 included in the gateway exchange 20 transmits time slots SD, 3-3.
Command to start communication using 3U3-3 (S
120).

Upon receiving this communication start command (S121>, wireless base i
1! 1st lap 30-3 sends communication start command to time slot 5
Send using D3-3 (3122>.

The mobile radio device 100 uses time throwers 1 to 5D3- using an ID signal which is an identification signal for identifying the mobile radio device.
Please confirm the start of communication by 3,5U3-3 5123>
, the radio base station 30-3 transmits a communication signal including the ID signal using the time slot 5U3-3.
-3.5U3-3 reports that communication has started (S
125).

S/N monitoring unit 2 of barrier exchange tXN20 that received this report
5 confirms the start of communication by time slots 5D3-3 and 5U3-3 5126>, measures the quality level of communication between the mobile radio Ia 100 and the radio base station 30-3, and measures the quality level of communication at a certain quality level 12 or higher. When we detect that (
S127YES, FIG. 7D), time slot 5D between radio base station 30-1 and mobile radio 100 (B)
I-1゜5 Instructs the wireless base stations 30-1 and 30-3 to stop communication using UI-1 (3128
).

As a result, the wireless base station 30-1 uses channel CI-1.
Communication by time slot 5D1-1.5U1-1 of 1 is turned off (S129). Furthermore, the wireless base E30'-3, which received the command to stop communication by channel CH1, forwards the command (5130), and this channel Cl-11
When the mobile radio device 100 receives a communication stop command from (
S131), the changeover switch 122-2 continues to turn on and off at predetermined timing, and the channel CH1 time slot 5D2-2.3D3-3.5U2-2,5
By activating only U3-3, channel Cl-
11. A communication stop report from time slot 5U1-1 is sent using time slot 5U3-3 of channel CHI (3132). Radio base station 30- which received this
3 is this channel CH1° time slot 5U1-
1 transfers the communication stop report (8133).

The communication control unit 21 of the gateway exchange 20, which received the communication stop report from the channel CH1 and the time slot 5UI-1, controls the switch 5W2-1-1.3-1- of the switch u23.
1 is left on, and the switch 5W1-1-1 is turned off (S134>.

As a result, the channel switching operation period ends, and with the switch 5W2-1-1. is wireless base station 30-2.30-3
Communication can be continued between the two terminals without any instantaneous disconnection or noise (S135).

In the above description, when performing channel switching during a call in the system of the present invention, the same wireless channel can be applied to v1 between adjacent zones. This means that when performing time-division communication as in the present invention, even if the same radio channel is used in two adjacent zones in a small zone method, in a system that does not transmit radio waves in empty time slots, the time This is because if the slots are left open, there is no risk of radio interference occurring as described above. Of course, the present invention can be applied without any problem even under the condition that reuse of the same radio channel within a repeated zone is prohibited, as adopted in the conventional small zone system.

In the example of channel switching operation described above, the circuit configuration of the mobile radio device 100 in FIG. 1E includes one radio receiving circuit 135 . When switching channels during a call using the wireless transmission path 132, it is rare to process the call signals of the time slots of the old and new channels that exist simultaneously. In this case, the time slots assigned to the old and new channels have the same timing (for example, the second
5D1-1 and 5D2-1 in Figure C. 5U1-1 in Figure 2D
, 5U2-1), the transmitting/receiving mixer 133,
There is a possibility that cross-modulation occurs in 136 and adversely affects communication quality. In order to prevent this, it is sufficient to avoid assigning time slots (~) with the same timing.
However, the situation remains the same.

When it is desired to allocate one time slot at the same timing, a mobile radio device 100B as shown in FIG. 1D may be used. In this case, as shown in the figure, two sets of wireless transmitting and receiving circuits 132-1.132-2.135-1.135
Since it has -2, there is no risk of radio interference. Moreover, it also has the advantage of being able to perform constant transmission and reception diversity.

(5) Transmission/reception diversity performed between multiple radio base stations Figures 88 to 8D show the operation when transmitting/receiving diversity of the system shown in Figures 18 to 1D is executed. A flow chart showing the flow is shown.

Gateway exchange 20. Radio base station 30-1, 30-2 and mobile radio] OO starts operation, and barrier exchange tEi20
The switch 5WI-1-1 of the switch group 23 included in the switch 5WI-1-1 is on, and communication is in progress between the wireless base station 30-1 and the mobile wireless device 100. For this communication, barrier exchange 15N2
Time slots 5D1-1, 5U1- of the wireless chitnel CH1 instructed by the communication control unit 21 included in
1. Downstream frequency F and upstream frequency f1 are used (
S301, Figure 8A>.

In the following description, the mobile radio 100B shown in FIG.
(denoted simply as mobile radio 100).

It is assumed that the mobile radio device 100 continues to communicate with the radio base station 30-1 and decides to perform transmission/reception diversity with other nearby radio base stations 30 in order to maintain or improve communication quality. (3302>. This decision is sent to the wireless base station 30-1 by an out-of-band control signal (
303), the radio base station 30-1 receives this 304
), and transfers it to the gateway exchange 20 (3305). The barrier switch 20 receives this signal (3306). Search the communication traffic situation near the mobile radio device 100 (S3
07). As a result, if abnormal traffic congestion is found (3308 YES), the radio base station 3 instructs the mobile radio device 100 that transmission/reception diversity cannot be implemented.
0-1 (3309). Also, if there is no traffic congestion (3308NO>, wireless base station 30-1
Wireless base station 30-
The uplink frequency f1.1 used for communication between the mobile radio device 100 and the mobile radio device 100. An instruction is given to monitor and receive the signal of time slot SUCO1 (S310, FIG. 8B).

Each surrounding wireless base station 30 that has received an instruction to monitor reception (for example, in 30-2>, monitor and receive the signal of frequency f1.time slot 5U1-1 5311), transmits the result to the S/N of the barrier switch 20. Please report to the monitoring department 2233
12.3313), the monitor reception quality from each wireless base station 30 is measured and compared, and it is detected that, for example, the call quality of the wireless base station 30-2 is better than a certain standard level L2 (S314YES).

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.
determines that the wireless base station 30-2 has moved to a zone covered by 5315),
As a result, time slot 5D of channel Cl-12
2-2.5LJ2-2 is determined (3316). The communication control unit 21 provides the control unit 140 with the transmission unit 132 (132-2> and the reception unit 135 (132-2>) of the mobile radio device 100.
135-2> to also operate time slot 5D2-2.5U2-2 of channel C1-12 to prepare for communication by transmitting and receiving diversity (S31
7).

Time slot 5D2-2 of this channel Cl-12
, 5U2-2 is sent to the radio base station 30-2, and prepares for communication using time slot 5D2-2.5U2-2 of channel CH2 (3
318). This command is simultaneously transmitted from the radio base station 30-1 in time slot 5D1-1 of channel CI-11 (S319). The mobile radio 100 uses this channel CH2, time slots 5D2-2, 5U2-
2. Receive a communication preparation command using transmit/receive diversity using frequency 02 (3320), channel CH2,
Preparation to enable communication including time slots 5D2-2 and 5U2-2, that is, frequency 02 is received from the control unit 140 to the synth 4 noisers 121-25 and 121-4. , and the transmitting/receiving intermittent controller 123 starts the operation of using the time slot 5D2-2.5U2-2 (S321).

While communicating with mobile radio 130-1 using time slots 5D1-1.5U1-1 of channel CH1, time slots 502-2, 5U2 of channel Cl-12
-2, when the mobile radio 10 is ready to communicate using
0 reports readiness on channel CI-(2's time
A report is made to the wireless base station 30-2 using slot 5LI2-2 (S322). The radio base station 30-2 that received this report receives the radio base station 30-2 using the time slots 5D2-2 and 5U2-2 prepared in step 8318.
Wl confirms that the preparations within 2 have been completed and sends a report to the barrier exchange FA 20 (S323).

When the gateway exchange 20 confirms the completion of communication preparation between the wireless base station 30-2 and the mobile wireless device 100 using the time slot 5D2-2.5U2-2 (S324),
The switch 5W1-1-1 of the switch group 23 is left on, and the switch 5W2-1-1 is also turned on (S32
5). Therefore, the communication control unit 21 included in the barrier switch 20
commands the wireless base station 30-2 to start communication with the mobile wireless device 100 using time slots 5D2-2 and 5U2-2 (8326, FIG. 8D).

Upon receiving this communication start command (3327), the wireless base station 30-2 transmits the communication start command in time slot 5D2-
2 (3328).

The mobile radio device 100 receives the time slot 5D2-2 using an ID signal which is an identification signal for identifying the mobile radio device.
．． Please confirm the start of communication by 5LJ2-2 3329)
, using time slot 5U2-2, transmits a communication signal containing ID (g) 5330, and receiving this communication signal, radio base station 30-2 transmits the communication signal using time slot 5D2.
-2.5U2-2 reports that communication has started (S
331).

S/N monitoring unit 2 of barrier exchange Bl 20 received this report.
2 is time thrower! -3D2-2.5 Confirm the start of communication by U2-2 (3332), measure the quality level of communication between the mobile radio device 100 and the radio base station 30-2, and confirm that it is at a certain quality level of 12 or higher. Detect (S
333 YES).

As a result, the transition period to the transmitting/receiving diversity operation is completed, and with the switches 5W1-1-1 and 5W2-1-1 in the on state, the transition period between the wireless base station 30-1 and the wireless base station 30-1 is completed in step 33.
01, and between the wireless base station 30-2, channels C1-12, downlink frequency G2, and uplink frequency g
2, the mobile radio Ia 100 can continue communication using transmitting and receiving diversity (3334).

In this transmission/reception diversity communication, the switches 5WI-1-1 and 5W2-1-1 of the switch group 23
Both radio base stations 30-1 and 30-2 are in the on state, and the same call signal as that of radio base station 30-1 is sent to radio base station 30-2.
The length of the time slot, including the modulation depth of the -2 modulator.

The number within one frame, the timing of each radio channel, etc. are also the same.

The two wireless base stations 30 and mobile thermal II device 1 explained above
Although the transmission/reception diversity performed between C1-11 and 0H2 is performed using separate radio channels for each, this is not necessary and may be done using the same radio channel. The time slots can also be chosen arbitrarily when using roughly the same or separate radio channels. These diversity effects will be explained next.

(6) Comparison of the diaperity effect according to the present invention and the conventional method (Fig. 9) shows the diaperity effect according to the present invention and the conventional method (
A comparison with carrier angle modulation or amplitude modulation is shown below.

First, in the transmitting/receiving diversity using multiple wireless base stations 30 explained in section (5), it is possible to implement the transmission/reception diversity using the same channel or different channels in the multiple wireless base stations 30. Communication can be performed using the same time slot or separate time slots, and a diversity effect can be obtained. Furthermore, since these radio base stations 30 are located at different locations, there is no cross-correlation in terms of transmission and reception characteristics between the antennas, and it is clear that a diversity effect can be obtained.

Next, in transmitting and receiving diversity using the same radio base station 30 according to the present invention, since the locations are necessarily the same, the diversity effect cannot be obtained if the same channel and the same time slot are used. . In space diversity, unless the transmitting and receiving antennas are separated by an appropriate distance, the correlation coefficient between the antennas will not approach zero and a satisfactory effect will not be achieved.

On the other hand, in the conventional method, when multiple radio base stations are used, the space diversity effect can be obtained on both the same channel or different channels, but the space diversity effect can be obtained for each time slot. Since it is impossible to achieve this, naturally the diaperity effect cannot be obtained. When using roughly the same radio base station, an effect can be obtained when using different channels, and although there is a slight space diversity effect, the same channel,
It will not be possible to use the same time slot or different time slots.

From the above evaluations, it has become clear how effective the transmitting and receiving diversity according to the present invention is.

Note that in the case of a diversity configuration in which the same radio channel is used, the configuration of the mobile radio device 100 can be simplified. A mobile radio device 100C having such a configuration is shown in FIG. 1E. Although FIG. 1E only has one pair of transmitting and receiving radios, it is clear that transmitting and receiving diversity can be implemented with the configuration shown in the figure as long as the same radio channel is used. Probably.

Also, three or more different wireless base stations 30 and mobile wireless devices 10
It will be easily understood from the above description that transmission/reception diversity can be implemented using many time slots with respect to 0C.

(7) Measures to take when call traffic congestion occurs in a specific wireless zone Mobile radio 111 at base station 30
Wireless channel used for communication with 00.

10A to 10D below.
As explained using the diagram, even if there is a congestion of call traffic in a specific wireless zone, if there is an empty channel (empty time slot) in the wireless base station 30 in the surrounding zone, it can be temporarily used. It is possible to take measures against congestion by borrowing it.

Now, the barrier exchange FM 20 constantly monitors the ever-changing state of call traffic of each radio base station 30 under its control, as well as the status of the used channels, time slots, and continues optimal system operation management. Furthermore, the radio channel time slots used by each radio base station are determined in advance by estimating the traffic occurring within each novice zone.

Assume that a call is made from mobile radio 100 in this state. Then, an off-hook signal is transmitted from the mobile radio device 100 to a nearby radio base station, for example, 30-1.3.
0-2 (S401, FIG. 10A). The state at this time is as already explained in FIG. 5A.

Now, the off-hook signal from the mobile radio device 100 is received by the surrounding radio base stations 30-1, 30-2, etc., and the ID
After search (3402, 3403) Call signal or barrier exchange F
It is sent to A20 (3404.8405). Upon receiving this, the gateway exchange 20 searches the ID identification storage unit 24 (5406) and begins the process of determining the radio base station 30 with which the mobile radio 100 is to communicate, and the radio channel and time slot to be used there. At this point, the call traffic within the wireless base station 30 responsible for communication is normal.
If there is a free radio channel and a free time slot (S407 YES), the operation of step 3206 without step 3230 described in FIGS. 58 to 5C is continued. However, the call traffic is light and there are 30 km of free wireless channels at the wireless base station.

If it turns out that there are no free time slots (3
407 NO>, the call traffic state in the nearby wireless base stations 30 is searched (S408, FIG. 10B).

As a result, if the call traffic is normal at these radio base stations 30 (3408 NO>), it is determined that the call cannot be made, and the call is sent to the mobile radio device 100 that made the call.
Control signal CH via radio base station 30-1.30-2
1,5D1-n> to inform that the call cannot be made (3409).

Furthermore, if the call traffic in the surrounding radio base station 30 is normal and there are free radio channels and free time slots, it is decided to temporarily divert these. That is,
Communication channel CH1, time slot 3 (SDl-3>) of radio base station 30-3, communication channel CH1, time slot 4 (SDl-4>) of radio base station 30-4
3410), and notifies the wireless base station 30-1.30-2 of this decision (3411).

Radio base stations 30-1, 30-2 that received this decision confirmed that they were unused (Shun (3412, 3412, 30-2)).
5413), channel C between wireless base #30-1
H1, time slot 3, also from the wireless base station 30-
2, designation signals that enable the use of channel CH1 and time slot 4 are transferred to mobile radio device 100, respectively (S414, 3415, FIG. 10C). The following operations are performed for time throwers 1 to 1, 2 among the operations in steps 5212 to 5230 in FIGS. 5B and 5C.
are read as 3 and 4, respectively, and the call is established (8416, Figures 10C to 543).
5 Figure 10D).

The specific wireless base station base station 30-3.3 explained above
The transfer of radio channel time thrower 1 from 0-4 to other radio base stations 30-1, 30-2 is performed according to the following priority order.

1) At the radio base station 30 where the traffic is cleared, the radio channel, time and
Even when slots are used, there is no risk of co-channel interference with signals being communicated in other wireless zones.

11) The traffic G of the calls 1 to 3 of the surrounding radio base stations 30 that are determined to be divertable is small even when compared to the radio base station 30 of Zaraanihaku, which has the possibility of diversion.

iii) Even if a new call is made or received, it can be handled by a specific wireless base station 30 in the vicinity that is determined to be reusable based on the hardware configuration. Specifically, if the wireless base station 30-3 has a hardware configuration that allows transmission and reception of each time slot of wireless channels CH1, CH2, and CH3, even if the time slots of wireless channels CH1, CH3 are diverted to others, Even if CH2 becomes unavailable, CH3 must have enough free time slots to accommodate increased traffic.

In addition, in the explanation of FIGS. 10A to 10D, when the mobile radio 100 makes a call, the mobile radio 30-1.3C)
-2 corresponds to the state in which diversity transmission and reception is executed. However, this is not always necessary, and if the traffic is to be further reduced or if diversity transmission/reception is not suitable due to the hardware configuration of the mobile radio device 100, one of the radio base stations 30-1 Of course, it is also possible to communicate with a station.

Hereinafter, it will be explained that the present invention is cheaper and more economical than the conventional method as a traffic width improvement measure. In other words,
Of the above, iii) is a feature of the present invention that cannot be obtained with conventional analog systems. In the conventional system, this is called dynamic channel alignment, in which each radio base station 30 is equipped with hardware that is not used under normal conditions in order to provide smooth communication traffic. To explain specifically, each radio base station 30 has communication channels CH101 to
In addition to normally used radio equipment, transmitting/receiving equipment for 10 V channels of 110 is provided, and when a traffic clearing occurs, it is used only at the radio base station 30 where the clearing occurs.

This is economically disadvantageous because it forces expensive wireless equipment to be used for a large amount of time. However, in the present invention, the same effect as that of the conventional method can be obtained by using a method of repurposing time slots, which hardly requires any new equipment in terms of hardware.

(8) Detailed Description of the Present Invention Next, we will theoretically explain how the present system can be used to perform signal transmission in good conditions without adversely affecting other wireless channels in the system. for that,
Let us take an example of an uplink radio signal (transmitted by the mobile radio device 100 and received by the radio base station 30).

First, assume that all uplink radio signals are empty lines, that is, all time slots are not used. The mobile radio 81100 that wishes to make a call uses the
For example, by the control signal of time thrower l-SDl,
When the mobile radio 100 selects an available time slot (for example, time slot 5D1) of an uplink radio channel, a control signal (if a communication path is established) is sent from the radio transmission circuit 132 in response to a signal from the timing generation circuit 142. A call signal) is sent to the wireless base station 30.

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

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

The data or call 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.

Also, the υ control signal that exists outside the band is μ(t)=,Σa・CO3(ω・t+θi)CI=m+
1 l 1 Here, a・ is the magnitude of the amplitude, and ω1 is the stratum corneum of the signal? The wave number and θi represent the phase when 1=0. m.

n represents a positive integer.

Next, the case of frequency modulation will be explained, but the present invention is similarly applicable to both phase modulation and amplitude modulation. When the carrier wave is frequency modulated using equation (1) or equations (1) and (2), the modulated wave 1q is: I= I□ sin f (ω0μ(t)) dt−Io
sin(ωt+5(t) > (3) or 1=I□ sin f(ω10μ(1)10μ.(t)
)dt-isin(ωt+5(t)+5o(t))where m・=ai/ωH5i=1.2.3. ..., n)
5(t)+5o(1) shown in equation (4) represents a general form of transmission signal.

Now, using equation <3> or equation (4), mobile radio B
The radio signal sent from the antenna of N100 is expressed by the following formula.

I = (I01/n) [1+2 El(n/m''
)) xsin (myr/n) cos mp t
]xsin (Ω1t+51(t)+5o1(t))
However, n is the number of slots (equal time intervals) within one frame, p is the switching angular frequency, and m is a positive odd number.

Equation (5) is the mobile radio device 10 using the same radio channel.
This was necessarily the case when the transmission signal from 0 to slot 1 in one frame was one round, but all slots were implemented with signals, that is, the mobile radio device 100 of NG was on the same radio channel. The mathematical expression of the signals included in the wireless channel when communication is in progress using

I= (I01/n> [1+2U1(n/ml)x
sin (myr/n)cosmpt]xsin (
Ω t+s (1)+5o1(t) )+ (102
/ n) [1+2 F, (n/mπ))xsin
(mπ/n> xcos mp (t-2'yr/ (np)) ]
xsin (Ω i + S 2 (1) + 5o2 (t)
＞+(Io3/n)N+2Σ (n/mπ)) m=1 xsin (mπ/n) xcos mp (t-4yr/ (np) ) ]x
sin (Ω3 j + S 3 (t) + S c
3(1)) +... + (1o, /n) [1+2Σ (n/ml) m=1 xsin (myr/n) xcos mp (t-2(n-1) yr/ (no
) ) ]xsin (Ω, t+s, (t) +s
o, (t)) However, p is a positive odd number for the same angular frequency of V'J switching angle, and switching times for n input waves are set at equal intervals.

The radio signal transmitted from the radio base station 30 in FIG. 1Δ 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 thrower j-S D 1 shown in FIG. 2A for the mobile radio 100-1, (
6) This becomes the first term on the right side of the equation, that is, the signal shown on the right side. When the equation (5) passes through the amplitude limiter included in the receiving section 137 in FIG. 1B-1, it takes the form shown in the following equation.

1=Asrn (Ω1t+51(t)+5c1(t)
>(5') However, A is the amplitude and is not related to frequency or time.

When equation (5') passes through the frequency discriminator included in the receiving section 137, the demodulated output is e(t)=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 1100 itself as in the case of the mobile radio 100, it is necessary to receive all the signals sent in chronological order from a large number of mobile radios 100. They must be different in some way.

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

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

1-(I01/n) [sin (Ω1 to 10u1
(t))+(n/π)Sin(π/n) x[5in((Ω1+p)t+U1 (t))+5in
((Ω −p〉↑+CJ1(t) ) ]+ (n/3
π) sin (37r/rl) x [5in((Ω1-
+-3p)↑+U1(t)-(6π/n)(n-H) +5in((Ω1-3p)t+U1(t)+(6π/n
> (n-1))] + (n15yr) sin (5π/n>x[5in
((Ω1+5p)t+u1(t)−(10π/n)(n
-1>) +5in((Ω1 5p) t+LJ1(t)+(10
π/n) (n-1>) ko+----- ko+(I02/n) [sin (Ω2 j+U2
CD ) + (n/π) sin (π/n”) x [5in ((Ω2 +p) i:+U2 (t) )
+5in ((Ω2-p) t+U2 (t) ) '1
+ (n/3yr) sin (37r/n) x [5i
n((Ω2 +3 p) t +U2 is)−(6π/
n) (n-1>) +5in((Ω2 3D)↑+U2 (t)+(6π/
n>(n-1>)] + (n15π) sin (5π/n>x[5in(
(Ω2 +5D>t+U2(1)-(10π/n>(n
-1>) +siro ((Ω2 5p)j+U2 ([)+(
10π/n>(n-1>)] +・・・・・・]
+(Ion/n)[5in(Ω,t+Uo(t))+(
n/π) Sin(π/n) x [, sin ((Ω 10p)t+U.(t))1+
−5in((Ω −p)t+U,(t)) ]+ (n
/3π) sin (3π/n)X[5in((Ω, +
3p)t+U,(t)-(6π/rl)(n-1>) +5in((Ω-3D)t+U,(t)-(6π/n
)(n-1>)] + (n15yr) sin (57r/rl)x[5
in((Ω.+5p)t+Un(t)−(10π/n)
(n-1>) +5in((Ω-5D)t+Uo(1)-(10π/
n>(n-1>)] 10... ](7
〉 However, U・(t)=S・(t) 10s. , (1) (i=1.2.
..., n) If we look at equation (7) here, we can see that it is a combination of many carrier waves.

Adjacent wireless channel interference, which is a problem in system construction, is as follows:
It will be explained that the system according to the present invention can be operated without any problems in practical use by conducting a qualitative evaluation of co-radio channel interference and the amount of delay time of transmission signals.

(I) Adjacent radio channel interference The number of time slots within one frame is 1 to 10. Taking as an example a case where the audio multiplicity is 10.1 and the frame period is 100 msec, it will be explained in a fixed manner below that most signal components remain within one channel and have very little influence on adjacent channels. .

In equation (7), adjacent radio channel interference will be greatest when all implementations, that is, all time slots are in use. Also, for convenience of calculation, the carrier wave frequency Ωi <r=1.2 transmitted from each mobile radio device 100. ...,
n) and transmitted signal −<+=1.2. ..., n
) for Ω1=Ω2=...-Ω.

U1=u2=・=u.

However, the effect on the amount of interference is ignored (actually, this is the maximum amount of interference that can occur).

Furthermore, in an actual system, '01='02="""=l0n=10(8'), so equation (7) can be expressed as follows.

I/n= (I□/n) (Sin (Ω1
t+U1 (t) ) + (n/7r) Sin
(7T/n>x[5in((Ω1+p) t+
U 1 (t) )+5in((Ω1-p)t+U1(
t)) ] + (n/3π) sin (3π/n)x
[5in((Ω1+3D)t+U1([
)-(6π/n>(n-1>) +5in((Ω1 3D)t+U1(j)-(6π/n
)(n-1>)] + (n15yr) sin (5rr/n)X[5i
n((Ω +5p)t+U1 (i)-(10π/n)
(n-1>) +5in((Ω-5p)t+U1 (j)-(10π
/n>(n-1))]) ten...] As the value of p included in equation (9), the energy If (voltage) is expressed as a peak value (as a result, the influence of interference radio waves will be greatly evaluated), the following equation is obtained.

I/n=(I□/n)(1+(n/π)sin(π/n)+(n/3π)sin(3π/n)+・ )−(
Io/n”) ((n/π) sin(π/n)+ (n/
3 yr ) sin (3 yr/n ) +-) However, the position of the carrier frequency of the above interference radio wave from the perspective of other radio channels is n=O, that is, ±p, respectively, above and below the main carrier frequency. ±2p, ±3p,... They are far away. However, calculations continue based on the assumption that the area has the greatest impact.

Therefore, sin (π/n>, sin (3π/n).

Since the absolute value of 5in (5π/n), . In other words, if these are all set to 1, equation (10) becomes 1/I□ =1+ (n/π)(1+1/3+115+
...+1/(2n-1) +...) +(n/π) (1+1/3 +115+...+1/(2n-1) +...) The first right side of equation (11) The first term refers to the main carrier component, the second term <n/π) () refers to the subcarrier component in the upper frequency band of the main 110 transmission, and the third term (n/π) () indicates subcarrier components 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. (11
), of the reserved subcarrier energy (amplitude value) in the wireless channel, the energy within 10KH2 above and below the center frequency is compared with the energy within 10 to 20KH2. First, the energy (N
pressure value) E = (IOKH2) = 2n/yrx 5
．． 5506 Also, the energy E (2
0KH7) = 2n/yrx 0.1421 Therefore, R= E (20KH2) / E (10KHz)
= o, 0256, or approximately 1/40.

Similarly, if we calculate the energy required within 20 to 3 OKH2 above and below and compare it in the same way, we find that 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 the transmission output is still 99%
% or more of the energy exists within the transmission band of its own wireless channel, and the remaining energy of 1% or less may cause radio wave interference to other channels.

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

The adjacent channels shown in FIG.
KIIZ apart, and if the subcarrier frequency components of 75KH2 to 175KHz cause interference within this channel, the total power is 2n/πΣ from equation (11).
1/ (2n-1> =nx 0.0027n=375
1 On the other hand, since the energy of the main carrier wave (which is equal to the energy of the main carrier wave of the adjacent channel) is 1, the signal to interference radio wave ratio (hereinafter abbreviated as D/U) is 1/0.002.
7, which is 50 dB when expressed in decibels (however, it is a power ratio).

In the above calculation, p was 20π radians (IOH2), but a similar calculation is performed for the case where p is 100H2 (the purpose of increasing p is to shorten the signal delay time, as described later). and the signal-to-interference ratio is 30 dB.
(power ratio). By the way, in general mobile communications, the allowable D/U (signal wave to interference wave) value for co-channel interference is 24 dB (power ratio), so the above measurement value is satisfied with a sufficient margin. It shows that 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 the mobile radio device 100, but
Similarly, calculations can be made for transmissions from the wireless base station 30, and the results are almost the same. However, the wireless base station 30
In the case of transmission from , the usage conditions within the time slot for synchronization signals and control signals differ, and the usage frequency distribution within the time slot differs by this amount, but the effect is small.

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

This influence will be theoretically determined below.

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

xsin (in) m+ 1) π/n) [cos
((Ω+ (2m+1)p)t+U(t)) -COS((Ω-(2m+1)p)t+U(t))The concrete calculation of equation (16) has already been performed using equation (1). All you have to do is use the same numerical meter. Therefore, if the characteristics of the filter circuit included in the wireless transmission circuit 32 are wideband, m□ is, for example, 1000 (1
00 Hz x 1000 = 100 KHz) or higher, the influence of self-channel interference can be ignored. In an actual circuit, this condition can be easily satisfied.

(III) Co-channel interference Co-channel interference occurs when the present invention is applied to a small zone system, and when the same radio channel used in another zone, which is located in a different radio zone, This occurs when radio waves from the channel are mixed in.

In FIG. 12, a small zone covered by each wireless base station 30 is shown as a regular hexagon, and each wireless base station 30 is located at the center of the small zone.
is located. 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. 12, when the distance between two wireless base stations 30 using the same wireless channel (the shortest distance from the center of regular hexagon 1 to other regular hexagons 1) is d, It is necessary to find an allowable value of D/U (value of the ratio of desired wave input level D to interfering wave input level U). To do this, the D/U value can be determined by knowing the frequency used in the system, the transmission power (size of the wireless zone), and the radio wave propagation state. In the conventional analog system, the interference value is known for the D/U 1M obtained in this way, but in the present invention, the modulation mechanism is completely different, so it is impossible to apply the conventional technology. It cannot be determined accurately unless the system is actually constructed and measured. However, if conventional D/U allowable values are used, it is expected to be on the safe side.

(IV) Method for removing pulse noise during signal reception As already explained, the output signal when receiving the time division signal according to the present invention and obtaining the frequency (phase) discriminator output 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 discontinuities in different signals, and b) rounding of the signal waveform due to the band characteristics of the intermediate frequency amplifier 143. Things related to both transmission and reception include C> the difference between the timing of the signal speed conversion circuit group and the timing at the time of reception (including the 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 at the transmitting/receiving end (transmitting/receiving terminal) is due to the following factors.

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

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

iii) Signal transmission time due to the distance between the transmitter and receiver iv) When applying diversity transmitting and receiving and transmitting and receiving the same signal at the same time Other problems that occur in the IF circuit, the transmitting/receiving mixer circuit, the transmitting/receiving filter section, etc. Since the delay time is small, it is omitted.

Of the above, 1ii) means that, for example, in the aforementioned car phone, the distance between transmitting and receiving is approximately 10 cm at most (wired section is omitted).
Because there is 107/300000KIjX/Sec = 1/3
0 m5ec Also, for mobile phones, a system has been proposed in which the communication area of one wireless base station is made into a very small zone with a radius of about 25 m (Proposal of ItoP mobile phone system - An approach to ultimate communication)゛The Institute of Electronics and Communication Engineers Technical Report C8 Study Group November 1986 C386-88 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 (wired section is omitted), so 100 m/300,000 yen/sec = 1/3000
It is m5ec. Therefore, it can be ignored compared to i) and ii).

Now, the occurrence of the delay time of i>, ii) is schematically shown in FIGS. 13A and 13B.

In FIG. 13A, the input to the signal speed conversion circuit 51-1 in the signal speed conversion circuit group 51 of the radio base station 30 is applied as shown in (a), and (time flows from left to right) The signal A between T, which is the unit of speed (pitch) conversion, is compressed to T/n by the signal speed conversion circuit 51-1, and the trailing edge of the compressed signal A shown in (b) is The wireless transmitter circuit 32 outputs the same signal as shown in (C).
is output from. In the mobile radio device 100 that received this,
The speed restoration circuit 138 receives the compressed signal A at the timing shown in (d>) at the input of the speed restoration circuit 138, restores the signal A shown in (a), and outputs it as shown in (e). The delay time τ1 from the leading edge of the signal gA in ) to the leading edge of the signal in (e) is required by T-T/n.However, from the transmitter output section to the spatial transmission section and the receiving section output of the mobile radio 11100. The transmission time of is ignored.

In FIG. 13B, the signal speed conversion circuit 5 of the radio base station 30
In the input signal A shown in (a) to 1-1, the leading edge of the output signal gA compressed to T/n is output at the same time as the trailing edge ends. Therefore, the output of the radio transmitting circuit 32 becomes as shown in (C), and the mobile radio device 10 receiving the output
0 speed restoration circuit 138 becomes as shown in (d), and at the same time as the trailing edge of the compressed signal A, the leading edge of the restored signal A shown in (e) after being expanded by n times. is sent. Therefore, from what is shown in (e), T+T
A delay time τ2 delayed by /n=τ2 occurs.

Although the circuit for processing the signal shown in FIG. 13A is more complex than that shown in FIG. 138, the delay time can be reduced. On the other hand, in the case of FIG. 13B, 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. Be sure to include actual numbers. For example, if one time slot (one division) of a transmission signal is T = 1/10 seconds and time compression coefficient n' = 10, then 2τ1 = 2x1/10 (1-1/10) = 18/1
00=0.18 seconds (180ms) 2τ2 =2X1/10 (1+1/10)=22/1
00=0.22 seconds (220 msec). On the other hand, the delay time for satellite communication is approximately 250m.
Since it is in seconds, the above value is about the same as in the case of satellite communication. If it is desired to reduce the delay time, it is sufficient to reduce the time slot (one time interval) in the baseband.

In other words, the number of kings is decreased from the above example, and T=1/100.
seconds, time compression coefficient n=100, then 2τ1=2X
1/100) (1-1/100) = 2X99/1000
0 Cape 0.02 seconds (20 m seconds) 2τ2=2x1/100) (1+1/100)=202
/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 time slots for other communications are cyclically allocated. If given, it becomes possible to satisfy the above conditions. (The time for one frame should be reduced to 1/10).

The above is the delay time necessarily determined by system design, and the delay time of 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.

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 10KIIt from 0, the delay time difference is <1/30m5ec as described above. That is, since the time slot may double by about Q, 03 m5 ec, it is necessary to provide a protection time of about 0.05 m5 ec.

In the case of a mobile phone, in the above example, the distance difference between the two mobile radios and the radio base station 30 is 100 m, so the delay time difference is 0.0003 msec.

Therefore, in this case, it can be ignored in systems having signal components of 1 MHz or less.

Next, a description will be given of the delay when iv) diversity transmission and reception is applied and the same signal is transmitted and received at the same time. The delay time caused by applying diaperity is
Mainly receives control signals.

To obtain a diversity effect, for example, when mixing control signals sent using two time slots with different time slot numbers, the signal in the lower numbered time slot is temporarily buffered. This is because it is necessary to store the signal in a memory circuit or the like and wait for the signal to be sent later. From this point of view, if the occurrence of a large delay time is undesirable in the system,
It is possible to use time slot signals with little difference, for example, adjacent time slots, or to send signals in the same time slot using different radio channels.

Next, for audio signals, there is no need to pay attention to the above points. As is clear from Fig. 1D, etc., the sent signals are received, passed through the speed restoration circuits 138-1 and 138-2, and then added to the signal mixing circuit 152. The problem with delay is that lower numbered time slots only cause delay time, and voice signals in later time slots are delayed because the call signal from that time is speed-converted and transmitted. In addition, the timing of the start of the call signal is determined by the timing of the control signal at the time of call origination and reception, so even if the last number is given as the time slot number, that time will not be the same as the voice signal. This is the signal transmission start timing, and speed conversion is performed.Therefore, there is no difference in delay time depending on the time slot used.

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

1) Pulse communication of the present invention 1 radio channel with 10 time slots or audio 1
0 channel can be transmitted. The required frequency bandwidth is: 3 K1-1z x 10 = 30KI-1z By providing a protection band, it is ±40KH2 as shown in Figure 14 (a).
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) Since the baseband signal of 1 wireless channel is 1 audio channel, the required frequency bandwidth is 3K (ZX1=
3K to IZ ±8KH2 is required as a protection band, and the radio carrier interval is 12°5KHz as shown in Figure 14(b).
(In our country, this standard is widely used in cordless phones, etc. in the 250MHz/400MHz2 band.

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

Comparing the above two systems, the ratio between the present invention and the conventional example is 80:125=0.64. In other words, in the pulse communication according to the present invention, SCPC (Si
nglg Channel per Carrier)
It can be seen that a frequency band of only about 60% is sufficient compared to .

Furthermore, when the number of channels (number of simultaneous talkers) increases, for example, 100 audio channels, the required frequency bandwidth for pulse communication of the present invention becomes (3Kt-(z x
100 + 50 (guard band) KHz) x2 = 700 Kl-1z In conventional FM communication (SCPC), 12.5 KHz increases.

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

3) For DMS90 system (References: F, L
indell et al.”Digital Ce1lular
Radio for the19905
communications P, 254-2
65 Oct.

In this system, 10 audio channels (1 channel is 16 bits/second) can be multiplexed at a transmission rate of 340 bits/second, but the carrier spacing (required frequency bandwidth)
is 300 KHz.

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).

(9) Application of the present invention to communications using non-telephone systems (wideband signals) other than call signals The explanations in sections (1) to (8) above were based on the case where the signals mainly used were voice signals. The present invention is applicable not only to voice communication but also to communication using non-telephone signals, especially broadband signals.

Alternatively, voice and these non-telephone signals can be transmitted using the same radio channel. This will be explained below.

As shown in FIG. 3B, the signals included in each time slot shown in FIG. 2A all have approximately the same maximum frequency, which in this case was about 45KH2. Keeping this in mind, for example, if the highest frequency of the paceband signal, that is, the input signal to the signal speed conversion circuit group 51 shown in FIG. If signal speed conversion is performed to use 2g of slots, the highest frequency will be approximately equal to the voice signal of the voice signal, and adverse effects on radio interference will be avoided. It turns out that in order to do this, the speed of signal speed conversion should be reduced to 1/2 that of voice. Similarly, if the highest frequency included in a wideband signal such as an image signal is 10 times that of audio, then 1
It is sufficient to perform a signal rate conversion of /10 and provide 10 allocated time slots.

Next, in order to ensure smooth operation of the system, it is unwise to transmit signals with extremely different signal speeds on the same radio channel;

High-speed data (30K)-1z), wideband signal (3
00K I"Z) and allocate separate wireless channels. However, when communication traffic becomes clear, regardless of the above, if a system ratio configuration is adopted that allows the mixing of different types of signals, a system with high frequency utilization and robust against traffic fluctuations can be constructed. That will happen.

[Effects of the Invention] As is clear from the above description, by applying the present invention to a mobile communication system, it is possible to construct a system with higher frequency utilization efficiency than conventional systems. In addition, in order to increase the effective use of normal frequencies, other design parameters such as adjacent channel interference, co-channel interference, and delay characteristics of transmission signals that affect line quality can be designed to values that can be effectively ignored. be.

In general, by applying the present invention to a mobile communication system that uses a small zone configuration, it is possible to eliminate the problem that occurs when a zone change occurs during communication, as in conventional systems, which causes a temporary interruption in communication, but in the case of call signals. However, the problems that have been occurring in facsimile signals and data signals due to image quality deterioration and burst signal errors will be completely eliminated. In addition, it is possible to implement various types of transmitting/receiving diversity with the same wireless base station or multiple wireless base stations, making it possible not only to make calls but also to communicate using wideband signals, and to alleviate communication traffic fluctuations in specific areas. This makes a great contribution to improving communication quality and serviceability, so the effects of the present invention are extremely large.

[Brief explanation of the drawing]

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; FIGS. Figure 1E is a circuit configuration diagram showing another embodiment of a mobile radio device used in the system of the present invention, and Figure 2A is a time slot structure diagram for explaining time slots used in the system of the present invention. , FIG. 2B is a diagram showing the radio signal waveform of a time slot, FIG. 2C and FIG. 2D are time slot structure diagrams for explaining channel switching in the system of the present invention, and FIG. 2E (a) and ( b) is a spectrum diagram and a circuit configuration diagram for explaining a configuration example of a control signal used in the present invention; FIGS. 3A and 3B are spectrum diagrams showing spectra of a call signal and a control signal; FIGS. 4A and 4B 5A, 5B and 5C are flowcharts showing the flow of the call originating operation of the system according to the present invention.
Figures A, 6B, 6C, and 6D are flowcharts showing the flow of the call receiving operation of this system, and Figures 7A, 7B, 7C, and 7D are flowcharts of the channel switching operation of this system. Flowchart showing the flow. FIGS. 8A, 8B, 8C and 8D are flowcharts showing the flow of operation when transmitting/receiving diversity is implemented by this system. FIG. 9 is transmitting/receiving according to the present invention and the conventional method. 10A, 10B, 10C, and 10D are flowcharts showing the flow of operations when implementing countermeasures when call traffic is cleared by this system; Figure 11 shows the adjacent channels in this system! Figure 12 is a configuration diagram showing a small zone configuration to which the present invention is applied; Figures 13A and 13B are spectrum diagrams to explain radio wave interference to the channel; FIG. 14 is a timing chart for explaining delay time, FIG. 14 is a spectrum diagram for explaining the required bandwidth of the present system and the conventional system, and FIG. 15 is a conceptual configuration diagram for explaining the conventional system. 10... Telephone network 20... Gateway switchboard 21
... Communication control section 22-1 to 22-n ... Communication signal 23 ... Switch group 24 ... ID identification storage section 25 ... S/N monitoring section 30 ... Wireless base station 31
...Control/call signal processing unit 32...Wireless transmission circuit 35...Wireless reception circuit 3
8... Signal speed restoration circuit group 38-1 to 38-n... Transmission speed restoration circuit 39...
Signal selection circuit group 39-1 to 39-n...Signal selection circuit 40...Control section 41...Clock generator 42...Timing generation circuit 51...Signal speed conversion circuit group 51-1... 51-n...Signal speed conversion circuit 52...
Signal assignment circuit group 52-1 to 52-n...Signal assignment circuit 81...Call path control section 82...ID identification storage section 83...Switch group 91...Digital encoding circuit 92...・Multiple conversion circuit 100.100-1 to 100-n-...Mobile radio device 10
1...Telephone unit 120...Reference crystal oscillator 121-1.121-2...Synthesizer 122-1
．． 122-2...Switch 123...Transmission/reception intermittent controller 131-1, 131-2...Speed conversion circuit 132...
・Wireless transmission circuit 133... Transmission mixer 134...
Transmitting section 135... Radio receiving circuit 136...
Reception mixer 137...reception section 138-1, 138
-2...Speed restoration circuit 139...Signal division circuit 141...Clock generator 142...Timing generator 152...Signal mixing circuit 157...Speech quality monitoring section 162...Interference disturbance Detector 182: ID information verification storage unit.

Claims (1)

[Scope of Claims] Each radio base means (30) each covers a plurality of zones and constitutes a service area, and a timer for moving across the plurality of zones and communicating with the radio base means. - Each mobile radio means (100) using a radio channel carrying time-compressed and segmented signals in slots.
In mobile communication using barrier exchange means (20) for exchanging communications with A time period in mobile communication in which the barrier exchange means controls such that a part of the time slots assigned to the radio base means in the vicinity of the radio base means is temporarily assigned to the radio base means in which the call traffic is congested. Split communication method.