JPH02122736A - Ratio base station and mobile radio equipment for time division communication in mobile communication - Google Patents

Abstract

PURPOSE:To construct a system with high availability of frequency by dividing one radio channel into plural time slot systems in point of time, and performing communication by selecting one or plural time slot systems. CONSTITUTION:One radio channel is divided into the plural time slot systems in point of time since a radio base station 30 and a large number of mobile radio equipment 100-1 to 100-n in the service area of the base station exist and an arbitrary number of radio equipment can communicate with the base station 30. The communication is performed by selecting one or plural time slot systems and using them. When transmission is performed from another radio equipment to the base station 30 while one radio equipment is communicating with the base station 30, one of nonuse time slot systems in radio channels in use is supplied to the radio equipment from which the communication is requested newly, which enables the communication with the base station 30 to be performed. Therefore, it is possible to obtain the system with high availability of frequency.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a time division communication system for wireless communication channels in mobile communication. More specifically, a plurality of radio channels out of a number of radio channels provided to the system are provided, and one of a number of mobile radios within a service area uses this to communicate with an opposing radio base. While you are communicating with a station by setting up a wireless line, another mobile radio device wishes to communicate using one or more of the radio channels used by the mobile radio device you are communicating with. When a mobile radio has already communicated with the radio base station, at least one radio channel can be shared between the other mobile radio and the radio base station without adversely affecting the communication between the mobile radio and the radio base station that are already in communication. The present invention relates to a time-division communication system that allows transmitting and receiving diversity of multiple wireless channels and allows setting up independent wireless lines.

[Prior Art] In conventional mobile communications, for example, it has been adopted in the automobile system of NTT (Nippon Telegraph and Telephone Corporation), which is in commercial service. This will be explained with reference to FIG. A certain wireless base station 13 has a zone 14 which is its service area.
A plurality of radio channels are allocated to simultaneously communicate with a plurality of mobile radio devices 15 mounted in each of the many automobiles within the vehicle. On the other hand, each mobile radio device 15 is equipped with a function that allows selective use of one of a large number of radio channels (referred to as multi-channel access).

When communicating with the radio base station 13, the mobile radio device 15 uses a control signal to contact the radio network control station 12 via the radio base station 13, which determines the use of radio channels of a large number of radio base stations 13. , the system is configured to determine a communication channel number to be used for communication according to instructions from there, and to communicate with subscribers of the telephone network 10 via an exchange 11 including a switch SW.

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

[Means for solving the problem] A transmission signal (baseband signal) is divided into predetermined time intervals and stored in a memory circuit, and when read out, the data is read out at a predetermined speed n times faster than the speed at which it is stored in the memory circuit. It is built into mobile radio equipment and radio base stations in order to transmit and receive information intermittently in time by reading the signals in the time slots of , a switch for a radio receiving circuit having a receiving mixer that communicates with each other, a radio 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. A method of providing a circuit to intermittent the output of each applied synthesizer, synchronizing this intermittent state for both transmission and reception, and also synchronizing the same intermittent transmission and reception as above with that of a mobile radio device at a wireless base station communicating with the opposite side. and on the receiving side, in order to extract only the signals accommodated in the predetermined time slot series, the radio receiving circuit is opened and closed to receive the signal, and the signal obtained by demodulation is stored in the storage circuit. By reading out the data at a low speed that is one-nth of the speed at which it is stored in this memory circuit, it is possible to reproduce the baseband signal that is the original signal that has been transmitted, and also by using multiple time slot sequences. We have constructed a system that includes a mobile radio base station and a mobile radio equipped with multiple radios that can transmit and receive the same call signal.

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

[Operation] A radio base station and a large number of mobile radio devices exist within its service area, and in order for any number of mobile radio devices to be able to communicate with the radio base station, one radio channel is The system is divided into a plurality of time slot series, and a system has been constructed in which one or more of these time slot series can be selected and used for communication. If one mobile radio device is communicating with a radio base station and another mobile radio device sends a message to this radio base station, the mobile radio device that newly wishes to communicate will be sent to the radio channel that is already in use. By providing one of the unused time slot sequences to enable communication with the wireless base station, the plurality of sets of communications can be performed without interfering with each other, and It is now possible to carry out communications without adversely affecting one's own communications.

In addition, when communication traffic is slow, the same communication signal is added to one time slot sequence of each of multiple different radio channels, and the radio base station transmits this, and this is used as the signal of multiple radio channels. are received by a mobile radio equipped with multiple receivers so that they can be received at the same time, mixed at the input of the telephone (terminal unit), and transmitted signals from the mobile radio are transmitted by multiple transmitters to receive them at one time.・Enabled transmission using multiple wireless channels in slot series.

Furthermore, by selecting a plurality of time slot sequences from among many time slot sequences set within one wireless channel, it is possible to improve communication quality through diversity transmission and reception. In this case, multiple time points within the same radio channel
The same communication signal is transmitted from a radio base station in a slot series, received by a mobile radio, and mixed at the telephone (terminal) input, and the transmission signal from the mobile radio is transmitted at multiple times. Diversity transmission and reception was made possible by transmitting in a slot sequence, receiving this at a wireless base station, and mixing it.

Broadly speaking, by using the two types of diapersity described above in combination, it is possible to perform diapersity transmission and reception with a large diapersity effect.

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

In FIG. 1A, 10 is a general telephone network, and 20 is a gateway exchange for connecting the telephone network 10 and a wireless system. 30 is a wireless base station and a barrier exchange 112
0, a circuit for converting the signal speed, a circuit for allocating and selecting time slots, a control unit, etc. 100-n> and has a wireless transmitting/receiving circuit for exchanging wireless signals.

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

FIG. 1B shows a circuit configuration of a mobile radio device 100 that communicates with a radio base station 30.

Received signals such as control signals and call signals of the two channels received by the antenna section are transmitted to a radio receiving circuit 135-1 including a receiving mixer 136-1 and a receiving section 137-1, and a receiving mixer 136-2 and a receiving section 137, respectively. -1, and the communication signal that is its output is
The signals are input to two speed recovery circuits 13B-1 and 138-2 and a clock regenerator 141, respectively. The clock regenerator 141 regenerates the clock from the received signal and transmits it to the speed restoration circuits 138-1, 138-2 and the control unit 14.
0 is applied to the timing generator 142.

In the speed restoration circuits 138-1 and 138-2, the speed recovery circuits 138-1 and 138-2 receive

The speed (pitch in the case of an analog signal) of the compressed and segmented communication signal in the doubled signal is restored and applied as a continuous signal to the signal mixing circuit 152 and the control unit 140,
The signal mixed by the signal mixing circuit 152 is sent to the telephone unit 10.
1 and is input to the ID information verification storage section 182.

The communication signal output from the telephone unit 101 is divided by a signal division circuit 139, and then sent to two speed conversion circuits 131-
1,131-2 divides the communication signal at predetermined time intervals, increases the speed (pitch in the case of analog signals) (compresses), and transmits it on two channels. A wireless transmitting circuit 132-1 including a transmitting unit 134-1, a transmitting mixer 133-2, and a transmitting unit 13
4-2, and the transmission signal is sent out from the antenna section and received by the wireless base 830.

In the timing generator 142, the transmission/reception intermittent controller 123. Speed conversion circuit 131-1, 13
1-2. Necessary timing is supplied to the radio reception circuits 135-1, 135-2 and the speed restoration circuits 138-1 and 138-2.

Further, the clock from the clock regenerator 141 is also applied to speed conversion circuits 131-1 and 131-2.

This mobile radio 1100 includes a synthesizer 121.
-1 to 121-4, selector switches 122-1 to 122-4, and selector switches 122-1 to 122
-4 and a timing generator 142 are included, and the synthesizers 121-1 to 121-4 and the transmitting/receiving intermittent controller 123 can transmit and receive two channels simultaneously. It is controlled by the control unit 140 as follows.

A reference frequency is supplied from a reference crystal oscillator 120 to each synthesizer 121-1 to 121-4. 2
Frequency diversity is enabled by transmitting and receiving two channels simultaneously.

The ID information verification storage unit 182 receives identification information (ID) transmitted from the wireless base station 30 from the signal @ mixing circuit 152, collates it with the stored content under the control of the control unit 140, and stores it as necessary. do.

1C-1 to 1C-3 respectively show the overall configuration of the radio base station 30, a specific example of the switch group 83 which is a component thereof, and a signal rate restoration circuit group 38. Signal selection circuit group 39. Signal speed conversion circuit group 51. A specific configuration example of the signal assignment circuit group 52 is shown. Gateway exchange 20
The n-channel communication signals 22-1 to 22-n are connected to a signal processing unit 31 that forms an interface through a transmission path.

Now, as shown in FIG. 10-1, communication signals 22-1 to 22-n sent from the barrier exchange 20 are input to the signal processing section 31 of the radio base station 30. The signal processing section 31 is equipped with an amplifier for compensating for transmission loss, and also performs so-called 2-wire to 4-wire conversion. That is, the input signal and the output signal are mixed and separated, and the input signal from the barrier switch 20 is sent to many switches 5RA-1-1, 5RA-1-2, . . . as shown in FIG. 10-2. 5RA
-1-n, 5RA-2-1, 5RA-2-2゜・, 5R
A-2-n, ・, ・, 5RA-n-1゜5RA-n
-2,-,5RA-n-n, and 5RB-1-1,5RB
-1-2,..., 5RB-1-n, 5RB-2-1,
5RB-2-2,-.

5RB-2-n, ・-・-, 5RB-n-1, 5RB
-n-2,-, 5RB-n-n, and 5TA-1-1
, 5TA-1-2, · , 5TA-1-n.

5TA-2-1, 5TA-2-2,..., 5TA-2
-n, ・ , -,5TA-n-1,5TA-n-2
, -,5TA-n-n, and 5TB-1-1, 5TB-1
-2,-,5TB-1-n,5TB-2-1,3TB-
2-2,-,5TB-2-n,-...-,5TB-n-
1.5TB-n-2, -, 5TB-n-n, the signal speed conversion circuit groups 51A and 51B are
(See Figure 10-3). Further, a signal speed restoration circuit group 38A whose details are shown in FIG. 1C-3;
The output signal from B is transmitted to the barrier exchange 20 by the signal processing unit 31 via the switch group 83 as shown in FIG. 10-2 and FIG. 1C-1 using the same transmission path as the input signal. . Here, the switch group 83 is a transmission switch S
TA-1-1 to 5TA-n-n.

5TB-1-1 to 5TB-n-n, reception switches 5RA-1-1 to 5RA-n-n, 5RB-1-1 to 5
It is roughly divided into RB-n-n, but all of them have a communication path control section 8.
1, the switch group 83 is opened and closed to achieve the desired purpose, and operates to enable transmitting and receiving diversity.

The ID identification storage section 82 is used to identify and store the ID of the mobile radio device 100. Further, the communication path control unit 81
The switch group 83 is opened and closed according to commands from the control unit 40 to control the communication path, and the communication path control unit 81 also has the function of providing information and requesting control to the control unit 40. Among the above, the input signal from the barrier exchange 1120 passes through the switch group 83, and many signal speed conversion circuits 51-1
Signal speed conversion circuit group 51 each including groups of ~51-n
A and 51B, and undergo speed (pitch) conversion at predetermined time intervals. Further, the signal transmitted from the wireless base station 30 to the barrier exchange t120 is transmitted to the wireless receiving circuit 35A.
, 35B are sent to signal speed restoration circuit groups 38A and 3 through signal selection circuit groups 39A and 39B, respectively.
After being inputted to 8B and subjected to speed (pitch) conversion, it is inputted to the signal processing section 31 through a switch group 83.

Now, the control or call signal outputs of the radio receiving circuits 35A and 35B are input to signal selection circuit groups 39A and 39B, respectively, each including a set of signal selection circuits 39-1 to 39-n that select signals for each time slot. , here, speech signals are separated corresponding to each speech channel CH1 to CHn. This output undergoes signal speed restoration circuit groups 38A and 38B, each including a set of signal speed restoration circuits 38-1 to 38-n provided for each channel, to restore the signal speed (pitch), and then 83 to the signal processing unit 31 and undergoes 4-wire to 2-wire conversion, this output is sent to the barrier exchange 1120 as communication signals 22-1 to 22-n.
Sent as .

Next, the functions of the signal speed conversion circuit groups 51A and 51B 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 groups 51A and 51B is the same as when playing back audio recorded by a tape recorder at high speed, and in reality, for example, COD (
Charge Coupled Device),
13[3[) (BucketBriClade D
evice) can be used, and the memory used in television receivers and tape recorders that compress or expand the time axis of conversation can be used (References: Koita et al. A tape recorder that compresses and expands ``Nikkei Electronics'' 1976
July 26, pp. 92-133).

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

The control or audio signals output from the barrier exchange 20 via the signal @ processing section 31 are sent to the signal speed conversion circuit groups 51A, 5.
1B, and after being subjected to speed (pitch) conversion processing, it is applied to signal allocation circuit groups 52A and 52B that allocate signals for each time slot. The signal allocation circuit groups 52A and 52B are buffer memory circuits that store one section of high-speed signals outputted from the signal speed conversion circuit groups 51A and 51B, and are timing generation circuits that are given according to instructions from the control section 40. With the timing information from 42, the signal in the buffer memory is read and transmitted to the wireless transmission circuit 32. When viewed in terms of channels, this timing information is chronologically arranged in series without overlap, and when all control signals or call signals described below are implemented, it becomes as if it were a continuous signal wave. .

Another embodiment of a mobile radio, 100B, is shown in FIG. 1D. Here, the mobile radio device 10 shown in FIG. 1B
The difference in configuration from No. 0 is that four speed restoration circuits 138-1 to 138-4 and four speed conversion circuits 131-1 to 131-4 are provided. To explain its operation, the output of the receiving section 137-1 of the radio receiving circuit 135-1 is applied to both speed recovery circuits 138-1 and 138-3, and the The same communication signal is received using diaperity. Also, the receiving section 13 of the wireless receiving circuit 135-2
The output of 7-2 is applied to both speed recovery circuits 138-2 and 138-4, which receive the same communication signal using two different time slots in one other wireless channel. . Therefore, the outputs of the four speed restoration circuits 138-1 to 138-4 are transferred to the signal mixing circuit 1.
By mixing at 52, both time and frequency diversity effects can be obtained. In order to obtain such an effect, the control unit 140B performs a slightly different control from the control unit 140 in FIG.
A device with the same function can be used in B.

Radio transmitting circuits 32A and 32B of the radio base station 30 (since both have the same function, 32 is simply referred to as 32 in the following)
It is called. ) and the compressed signals of the radio receiving circuits 35A and 35B (hereinafter simply referred to as 35 as they have the same function) are shown and explained in FIGS. 2A and 2B. do.

The output signal of the signal speed conversion circuit group 51 (51A and 51B have the same function, so they are simply referred to as 51) is output from the signal assignment circuit group 52 (52A and 52B have the same function, so they are simply referred to as 52, and other components ) and are given time slots in a predetermined order. S in Figure 2A (a)
Dl, SD2, . . . , SDn indicate that the speed-converted communication signals are allocated to each time slot.

Here, one time slot accommodates a synchronization signal and a control signal or a call signal as shown in the figure. If 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), in the radio transmitter circuit 32, signals forming one frame in time slots SD1 to SDn are applied to the modulation circuit.

This time-series multiplexed signal is amplitude- or angle-modulated in the radio transmitting circuit 32 and then sent out into space from the antenna section.

When making or receiving a telephone call, the wireless base station 30
Regarding the transmission of control signals between the mobile radio 1100 and the mobile radio 1100, it is possible to use either within the speech signal band or outside the speech signal band.

Figure 3A shows these frequency relationships. That is, the same (a
) is an example of an out-of-band signal, and as shown in the figure, the low frequency side (250Hz) and the high frequency side (3850H2) can be used. This signal is used, for example, when it is desired to send a control signal during a call (for example, when it is desired to apply diversity).

These control signals are created in the control section 4o, and are also created and sent by relaying or converting the control signals from the barrier exchange t120 and the control signals from the communication path control section 81 in the control section 40.

The control signal sent from the mobile radio device 100 is received by the radio receiving circuit 35, processed by the control section 40, and sent to the communication path control section 81 and the barrier exchange 20 as necessary.

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

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

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

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

On the other hand, the signal sent from the mobile radio device 100 is received by the antenna section of the radio base station 30 and input to the radio reception circuit 35. In the case of diversity, the same signal is sent from the mobile radio device 100 using multiple radio channels, but the basic operation is the same as in the case of one radio channel, so in the following, only one signal is sent. A case will be explained in which the data is sent using a wireless channel. FIG. 2A (b) schematically shows this upstream input signal.

That is, time slot SU1. SU2. ...s
Un H, mobile radio 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. However, if the distance between the radio base station 30 and the mobile radio device 100 is small or depending on the signal speed, it is possible to omit the synchronization signal.

Furthermore, the waveform of the radio carrier wave of the above-described uplink radio signal within a time slot is schematically shown in FIG. 2B (C).

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

A timing signal from a timing generation circuit 42 that generates a predetermined timing is applied to the signal selection circuit group 39 according to a control signal instruction from the control unit 40, and a synchronization signal and a control signal are generated for each time slot SU1 to Sun. The signal or speech signal is separated and output. Each of these signals is input to the signal speed restoration circuit group 3B. This circuit is a speed conversion circuit 131 (first
It has a function to perform the inverse conversion shown in Figure B), thereby faithfully reproducing the original signal and transmitting it to the gateway exchange 20.

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

As shown in FIG. 1C-1, the control signal from the control unit 40 is sent to the radio transmitting circuit 3 in parallel with the output of the signal allocation circuit group 52.
Added to 2. However, depending on the size of the speed conversion rate, the signal allocation circuit group 5
It is also possible to add the output of 2 to the wireless transmission circuit 32.

Next, as shown in FIG. 1B, the mobile radio 1100 also has a circuit configuration that can handle the case where one communication path among the functions of the radio base station 30 is transmitted and received over two channels. Original signal, for example, a call signal (0.3K
H2~45KHz) is the signal speed conversion circuit group 51 (first
Figure C) shows the frequency distribution on the output side as shown in Figure 3.
The result will be as shown in Figure B. That is, if the audio signal is converted 15 times as described above, the frequency distribution of the signal will be expanded to <4.5 KHz to 45 KHz as shown in FIG. 3B. The figure shows a case where the control signals are simultaneously transmitted using the lower frequency band of the call signal. Among these signals, control signals (0, 2 to 4.
0KH2) and one call signal (S at 4,5-45KHz)
(denoted as Dl) is accommodated in a time slot, say SDl. The same applies to the speech signals accommodated in the other time slots SD2 to SDn.

That is, time slot sDr <r=2°3,
・, n> accommodates a control signal (0,2~45KHz>) and a communication signal @CHi (4,5~45KH2>. However, the signals in 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 simultaneously.

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

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

Further, the control signal input from the mobile radio device 100 to the radio base station 30 is input to the radio reception circuit 35, but a part of the output is input to the control unit 40, and the other part is input to the signal selection circuit group 39. The signal is sent to the signal speed restoration circuit group 38 via the signal speed restoration circuit group 38. After the latter control signal undergoes a speed conversion (conversion to a low speed signal) that is completely opposite to that at the time of transmission, it becomes the same signal speed as that used in the general telephone network 10 and is transmitted via the signal processing section 31. Sent to barrier exchange 1a20.

Next, the call originating/receiving operation of the system according to the present invention and the application of transmitting/receiving diversity will be explained using the case of a voice signal as an example.

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

When the mobile radio device 100 is powered on, the first
In the wireless receiving circuit 135 in Figure B, the downlink (wireless base station 30
→Mobile radio 100) Radio channel (channel CHI,
and CH2). If the system is provided with more than two radio channels, i) the two radio channels representing the highest and second highest received input fields; 11) as directed by the control signals contained in the radio channels; Wireless channel 111) The wireless channel (hereinafter referred to as channels CH1 and CH2) enters the receiving state according to the procedure defined in each system, such as a channel to fill an empty time slot among the time slots in the wireless channel. This is possible by capturing the 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 local frequencies that enable the synthesizer 121-1 to receive the radio channel CH1 and the synthesizer 121-2 to receive the radio channel CH2. Synthesizer 121-
1 side, the switch 122-2 is the synthesizer 121-2
Each side is in a state of collapse.

Then, when the handset of the telephone unit 101 is off-hook (starting making a call) (8201, FIG. 4A), the synthesizer 121-3 in FIG. A control signal is received from the control unit 140 to generate a local oscillation frequency that enables the transmission of the data.

However, speed restoration circuit 13B-1 and speed restoration circuit 1
It is assumed that 38-2 is already in operation.

Next, the output call control signal is sent from the telephone unit 101 using radio channels CH1 and CH2. However, speed conversion circuit 131-1 and speed conversion circuit 13
It is assumed that 1-2 is already in operation.

Now, the control signal for the above radio channel CH1 or CH2 uses the frequency band shown in FIG. 3A (b), and is transmitted using, for example, time slot Sun.

In the following explanation, the radio channel CH1 will be explained.

This is because the same operation as that of CH1 proceeds for radio channel CH2 as well.

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 control signal may be sent after one frame or roughly.
Transmitted using the same time slot in the next frame.

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 contains control information such as currently used time slots and unused time slots (empty time slot display).Depending on the system, time slotsor <r= 1.2°...
n) may only contain synchronization and speech signals when they are being used by other communications; By receiving this control signal, mobile radio m1oo 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 another system, there is a case where no empty slot is displayed in any of the time slots, and in this case, the following audio multiplex signals SD1, SD2, . ..., S
It is necessary to search for the presence of Dn one after another and check for empty time slots.

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

Therefore, assuming that the time slot Sun for uplink signals is an empty slot, it is decided to use this empty time slot, and the necessary timing is determined from the response signal from the radio base station 30 by sending out a control signal for calling. 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 call signal will not be properly transmitted to the radio base station 30 due to call collision, and the operation will have to be restarted from the beginning, but this probability is When viewed as a system, this value is kept to a sufficiently small value. If call collisions are to be further reduced, the following method may be used. If the mobile radio 11100 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 second half for others. This is the way to do it. In other words, the portion of the time slot used as a calling signal is divided into several types, and this is used to classify a large number of mobile radios into groups, and each group is assigned a time period within that one time slot. It is a way of giving. Another method is to create many types of frequencies for control signals, group a large number of mobile radios, and give these to each group. According to this method, even if control signals of different frequencies are transmitted simultaneously using the same time slot, no interference will occur at the radio base station 30. The above two methods may be used separately, or when used together, the effects will increase synergistically.

Now, suppose that the call control signal from the mobile radio device 100 is successfully received by the radio base station 30 and the ID (identification number) of the mobile radio device 100 is detected (3202). Search for time slots. The time slot given to the mobile radio device 100 may be Sun, but a search is performed just to be sure. It is mobile radio 1
00, it is also used to respond to simultaneous calls from other mobile radios, and to provide time slots suitable for service types and service classifications.

As a result, for example, if the time slot SD1 is vacant, the mobile radio 1100 uses the time slot SD1 of the radio channel CHI and uses the downlink control signal to send the time slot up (from the mobile radio 100 to the radio base station 30). SUl.

and instructs to use the corresponding downlink (radio base station 30 → mobile radio 1100) SDI (S203
). In response, the mobile radio device 100 transitions to a state in which it can receive data in the designated time slot SD1, and at the same time, in the time slot for the uplink radio channel corresponding to the downlink time slot SDI,
(see figure (b)). At this time, the mobile radio device 100
The control unit 140 operates the transmission/reception intermittent controller 123 and starts operating the switches 122-1 and 122-2 (S204>. At the same time, a slot switching completion report is sent to the radio base station using the uplink time slot SU1. 30 (S205) and waits for a dial tone (S206).

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

The radio base station 30 that has received the slot switching completion report (
S207>, sends a calling signal to the gateway exchange 120 3208>, upon receiving this, the gateway exchange 20 detects the ID of the mobile radio 100, and selects the necessary switch among the switch group included in the gateway exchange 20. Turn on (820
9>, send dial tone (3210, 4th B)
figure).

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

The above has been the explanation regarding the radio channel CHI, but it is confirmed that the same procedure as above is followed for the channel CH2, and that the communication path is set at approximately the same time.

There is no problem in the above example, but wireless channels CH1 and CH
Depending on the time slot number assigned to the audio signal in step 2, a time difference may occur between the audio outputs of the speed restoration circuits 138-1 and 138-2. need to be compensated for. This is not particularly technically difficult;
For example, if the time slot numbers assigned in each radio channel shown in FIG. 2A (a) are CHI p and CH2 q, then if p>q, the output of channel Cl-12 is the speed restoration circuit 138-. 1 (p-q) slots earlier. Therefore, in response to instructions from the control unit 40 of the wireless base station 30, a delay circuit (not shown) included in the signal mixing circuit 152 controls the channel CH for the time corresponding to (p-q) slots.
1 signal may be delayed and the signals may be mixed. This makes it possible to receive a signal with a frequency diversity effect. When a communication signal can be obtained from the signal mixing circuit 152 in this way, the telephone section 1 of the mobile radio 100
Since a dial tone is heard from the 01 handset, the dial signal begins to be sent.

The dial signal from this mobile radio device 100 is divided into two by a signal division circuit 139, and is divided into two by a speed conversion circuit 131-1.13.
The speed is converted by 1-2 and the two transmitters 134-1, 1
34-2 and transmission mixers 133-1 and 133-2, respectively, using uplink time slots SU1 of channels CH1 and CH2 (S213>).

Thus, the transmitted dial signal is received by the radio receiving circuits 35A and 35B of the radio base station 30. This radio base station 30 already responds to the calling signal from the mobile radio device 100, gives the time slot to be used, and also signals the signal selection circuit groups 39A, 39B and the signal allocation circuit group 52A of the radio base station 30. 52B and for example 39A and 52A for radio channel CH1.
, 39B and 52B are respectively assigned to the same channel CH2, and the upstream time slot SUI of channels CH1 and CH2 is received, and the upstream time slot SUI of channels CH1 and CH2 is
The state has shifted to the state where the signal of the downlink time slot SD1 is transmitted.

In addition, the communication path control section 81 selects a switch 5R for reception among the switch group 83 according to a control signal from the control section 40.
A-1-1 and 5RB-1-1, and switches 5TA-1-1 and 5TB-1-1 for transmission are set to the on state (FIG. 10-2). Therefore, the dial signal transmitted from the mobile radio 1100 passes through each signal selection circuit 39-1 of signal selection circuit groups 39A and 39B, and then passes through each signal speed restoration circuit 38-1 of signal speed restoration circuit group 38A and 38B. Here, the original transmission signal is restored and transferred to the gateway exchange 20 as a call signal 22-1 via the switch group 83 and the signal processing section 31 (
S214>, a call path to the telephone network 10 is set (32
15>.

On the other hand, an input signal from the barrier switch 20 (initial control signal,
When a call is started, the call signal) is sent to the switch STA-1-1, 5TB of the switch group 83 in the wireless base station 30.
-1-1, signal speed conversion circuit group 51A, 51
After receiving speed conversion in each signal speed conversion circuit 51-1 of B,
Each signal assignment circuit 52- of the signal assignment circuit groups 52A and 52B
1 gives the time slot SDI of radio channels CH1 and CH2. And wireless transmission circuit 32A
, 32B to the mobile radio device 100 using the time slot SD1 of the downlink radio channel CH1-CH2. The mobile radio device 100 is waiting for reception in each time slot SD1 of the radio channels CH1 and CH2, and is received by the radio reception circuits 135-1 and 135-2, and the output thereof is sent to the speed recovery circuit 138-1.138.
-2 is input. In this circuit, the original signal of the transmission is restored and inputted to the receiver of the telephone unit 101 via the signal mixing circuit 152. In this way, a high-quality telephone call using frequency diversity is started between the mobile radio device 100 and a regular telephone in the regular telephone network 10 (S216>).

The call is terminated by on-hooking the handset of the telephone unit 101 of the mobile radio 1100 (3217), and the end-of-call signal and the on-hook signal from the control unit 140 are transmitted to the speed conversion circuit 1.
31 from the wireless transmission circuit 132 to the wireless base station 30 (3218>, the control unit 140 stops the operation of the transmission/reception intermittent controller 123, and switches 122-1 to 122-4. They are fixed to the output ends of synthesizers 121-1 to 121-4, respectively.

On the other hand, in the control unit 40 of the radio base station 30, the mobile radio device 1
Upon receiving the call termination signal from 00, the switches 5RA-1-1, 5RB-1-1, 5TA-1-1, of the switch group 83 transfer the call termination signal to the gateway exchange 20.
Turn off 5TB-1-1 and end the call (3220)
. At the same time, signal selection circuit groups 39A and 3 in the radio base station 30
9B and signal allocation circuit groups 52A and 52B are respectively opened.

In the above explanation, the exchange of control signals between the radio base station 30 and the mobile radio device 100 was explained as not passing through the signal speed conversion circuit group 51A or 51B, the signal speed restoration circuit group 38A or 38B, etc. For convenience of explanation, signal speed conversion circuit groups 51A and 5 are used similarly to audio signals.
1B signal speed restoration circuit group 38A, 38B and signal processing section 3
1, communication can be carried out without any problem.

In the above explanation, from the beginning of the call, the wireless channel Cl-1
It applied frequency diversity by using CH1 and CH2. However, if the call traffic is busy or if another important subscriber makes a call, it may not be possible to use the two radio channels and only one radio channel can be used. Even in this case, although the diversity effect cannot be obtained, it is possible to make a call. That is, in the above explanation, it is sufficient to focus only on the operation of radio channel CH1 and ignore CH2.

On the other hand, when call traffic is slow and three or more wireless channels are available, the same method as above can be applied. However, it becomes necessary for the mobile radio device 100 to be equipped with three or more sets of transceivers. Although there is no problem in the above example,
When a plurality of radio channels are used and time slots with different slot numbers are used, a delay related to the difference in the time slot numbers occurs in audio output as described above. To this end, the control unit 140 of the mobile radio II 00 notifies the radio base station 3o of the assigned time slot number, and upon receiving this, the radio base station 3o compensates for the time difference included in the signal speed restoration circuit group 38. Delay circuit for (
(not shown) must be operated. The operation of the mobile radio device 100 above is the same as that of the mobile radio device 100B (
This can be applied to the operation shown in FIG. 1D).

(2) Incoming call to mobile radio device 100 The mobile radio device 100 is on standby with the power turned on. In this case, as explained in the section regarding the call origination from the mobile radio 100, the mobile radio 100 is in a standby state to receive downlink control signals on the radio channels CH1 and CH2 in accordance with the procedure determined by the system.

Assume that an incoming call signal to the mobile radio device 100 arrives at the radio base station 30 from the general telephone network 10 via the barrier switch 2o. These control signals pass through the signal speed conversion circuit groups 51A and 51B via the switch group 83 as the communication signal 22, similar to the voice signal, and are sent to the signal allocation circuit groups 52A and 52B.
The information is transmitted to the control unit 40 via. Then, the control unit 40 controls the communication path control unit 81 to transmit and receive switches STA, STB, and SRA of the switch group 83.

Check the switches that can be used as SRBs and instruct them to keep them in the on state. At the same time, an empty slot among the downlink time slots of radio channels CH1 and CH2 addressed to the mobile radio device 100 is used, for example, to use SDI to use the ID signal ten incoming call signal display signal ten time slots of the mobile radio device 100. Signal (For example, SUl corresponding to SDl is used for transmission from the mobile radio 100)
Send out.

In mobile radio device 100 that receives this signal, it is transmitted to control section 140 from receiving sections 137-16 and 137-2 of radio receiving circuits 135-1 and 135-2, respectively.

The control unit 140 transmits this signal to its own mobile radio device 100.
To confirm that it is an incoming call signal, the telephone unit 10
At the same time, the transmission/reception intermittent controller 123 is operated to stand by at the designated time slot SDI, 5LJ1, and the switch 122
-1 to 122-4 start turning on and off. In this way, a state has been reached in which high-quality calls can be made by applying frequency diversity.

However, even in the above state, the speed restoration circuit 13B-
1,138-2, and speed conversion circuit 131-1,13
1-2 is assumed to be in a dormant state.

Next, we will theoretically explain how this system can be used to perform signal transmission in good conditions without adversely affecting other wireless channels within the system. for that,
Uplink (transmitted by mobile radio device 100 (B), radio base station 30
Take, for example, the radio signal of channel CH1 (received by

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

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

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

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

Also, the control signal that exists outside the band is: where ai is the amplitude, ω; is the angular frequency of the signal,
ai represents the phase when 1=0. m.

n represents a positive integer.

Next, the case of frequency modulation will be explained, but the present invention is similarly applicable to both phase modulation and amplitude modulation. When the carrier wave is frequency modulated using equation (1) or equations (1> and (2)), the modulated wave )q is:
Slrl (ωt+5(t)) (3) or I= I□ sin f (ω10μ(1)10μ.(t)
)dt-IoSln (ω is 15(t)+5o(1)
) However, mi = ai /ωi (i=1.2.3...,
n) 5(t)+s shown by equation (4). (1) will represent a general form of transmission signal.

Now, using equation (3) or (4), mobile radio 1
The radio signals sent out from 100 antennas are expressed by the following equation.

I= (I01/n) M+2; 1(n/m7r) )
xsin (rrryr/n)cosmpt]xsi
n (Ω1t+51(t)+5o1(t)) where n is the number of slots (equal time intervals) within one frame, p is the switching angular frequency, and m is a positive odd number.

Equation (5) is the mobile radio device 10 using the same radio channel.
The transmission signal from 0 is in one of the slots nl [l in one frame, but in a state where all slots are implemented with signals, that is, n mobile radios 1100 use the same radio channel. The mathematical expression of the signals included in the wireless channel when the wireless channel is in communication is as follows.

1= (I01/n)[1+2E, (n/ml)xs
in (mπ/n)cosmpt]xsin (Ω1
t + Sl m + 5c1(j) ) (I02/n
) [1+2Σ (n/mπ)) m=1 xsin (mπ/n) xcos rr+p (t-2W/ (rl))]
xsin (C2i+32 (t) +5o2(t)
) (I o, 3/n) [1+2Σ (n/mπ)) m=1 xsin (myr/n> xcos mp (t-4yr/ (np)) ] x
sin (C3i + S3) + s c3(t
)(■oo/n) [1+2Σ (n,,'mπ) m=1 xsin (mπ/n> xcos mp (t -2(n -1) yr,/
(np) ) ]xsin (Ω t+5o(t) 10s., (t)) where p is the switching angular frequency, m is a positive odd number, and the switching times for n input waves are equally spaced.

Also C1. Different symbols are used for C2, . s・
B) and S. The same applies to 1(t) (i=1.2°..., n).

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

I = (I01/n > [sin (C1t +
U 1 (t) )+ (n/π) Si port (π/
n> X[C03((C1-p)t+U1(t))-cos
((Ω1+p)t+u1(t)) ]+ (n/3yr
) Sin (3π/n) x [cos((C1-3p)
t+u1(t))-cos((Ω1+3D)t+U1(
t))] + (n15π) sin (5yr/n)x
[cos((Ω1 5p)]+U1 (j))cos
((Ω1+5p) i+L11 (t) ) ]+...
... ] + (
I(>2/n>[sin (Ω2 t +LJ2
(t)+(n/π) sin(π/n〉 x[cos((Ω2 D＞ ]+U2 (j) )−
cos((Ω2+p)]+U2(t))]+(n/
3π) sin (3π/n) x [cos((Ω2-3
p＞ ]+U2 (j))−cos((Ω2 + 3
D ) t + U2 (t) ) ] + (n15π
) sin (57r/n>X[C03((Ω2-5p
)]+U2 (t))-cos((Ω2 +5 p>
'j+U2 (j) ) ] ten...
Co+ (10o/n) [sin
(Ω, ]+LJn(t) )+(n/π)Sin(π
/n＞x[cos((Ω −p)]+U,(t))cos((
Ω. +I) > t +U n (t) ) ]+ (
n/3yr) sin (3yr/n>x[cos((
Ω. −3p)]+Un(1))−cos((Ω +3D
)]+Uo(t)) ]] +(n15π) sin (5π/n) x [cos((
Ω, −5p) ]+tJ, (t) )−cos((
Ω. +5p)]+U, (t))]+・・・・・・
] However, U・(t) =S−(t) +5oi(t)(i=1.
2. ..., n) Here, looking at equation (7), it can be seen that it is a combination of many carrier waves.

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

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

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

Even if LJ1=U2=-=Un, the influence on the amount of interference is ignored (actually, this is the maximum amount of interference that can occur). Equation (7) is expressed as follows.

1/rl” (I(>1/n) (S!n (Ω
1 to 10 U1 (t) ) 10 (n/π) sin (π/
n) x [cos ((ΩID) ] + U1 (t)
)−cos((Ω +D)]+U1(t)) ]] + (n/3:rr)sin (37r/rl)X[
C03((Ω1 3p)]+U1 (j))−cos(
(Ω1+3p)]+U1 (t)) ]+ (n15π
) sin (5π/n) x [cos ((Ω1 5p)
]+U1 (t))-cos((Ω1+5p)]+U1
(t))] )+・・・・・・ As the value of p included in equation (9), assume that the frequency is 20π radians, that is, the frequency is 10H2, the phase of the carrier wave is ignored, and the energy (voltage) is When expressed as a value (this results in a greater evaluation of the influence of interfering radio waves), it becomes as shown in the following formula.

I/n=(I./n> (1+(n/π)Sin(π/n)+(n/3π)sin(3π/n)−+−”)(
I □ / rl ) ((n / 7r ) S i
n (7C/ n >+(n/3yr) sin(3
yr/n)+-) However, the position of the carrier frequency of the above-mentioned jamming radio waves from the perspective of other radio channels is p=O, that is, ±p, ±2p, ±3p, etc. above and below the main carrier frequency, respectively.・Stay far away. However, calculations continue based on the assumption that the area has the greatest impact.

So, sin (yr/n), sin (3π/n),
Since the absolute value of sin (5π/n), . In other words, if these are all set to 1, equation (10) becomes I/I□ =1+ (n/π)(1+1/3+115+
...+1/(2n-1) +...) +(n/π) (1+1/3 +115+...+1/ (2n-1)+...) The first right side of this equation (11) The first term refers to the main carrier component, the second term (n/π)() refers to the subcarrier component in the upper frequency band of the main carrier, and the third term (
n/π)() represents the subcarrier component in the lower frequency band.

When the energy distribution of a large number of carrier waves shown in equation (11) is shown on the frequency axis, it becomes as shown in FIG. From equation (11), among the DIW1 transmitted energy (amplitude value) held in the wireless channel, the energy within 10 Hz above and below the center frequency is compared with the energy within 10 to 20 KHz. First, the energy (voltage value) within 10KHz IE = (10 to H2) is E (10KHz)
= (2n/x) Σ 1/ (2nn=1 ≠2/πx 5.5506 Also, the energy E(2
0KH7) is Mo2/πX O,1421 Therefore, R= E (20KH2) / E (IOKH2)
It can be seen that the value has gradually decreased to 0.0256, or approximately 1/40.

Similarly, if you find the energy within 20 to 30 KH7 above and below and compare it in the same way, it will be 0.00761 or about 1/1
It has gradually decreased to 30.

The above N calculation example is the result of calculation emphasizing the existence of a large number of subcarriers, but despite this, 99% of the transmission output
% or more of the energy exists within the transmission band of its own wireless channel, and the remaining energy of 1% or less may cause radio wave interference to other channels.

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

Adjacent channels shown in Figure 5 have a channel spacing of 125K.
H2 apart, and if the subcarrier frequency 75KHz to 175Hz component causes interference in this channel, the total power is calculated from equation (11).On the other hand, the energy of the main carrier (this is (equal to the energy of the main carrier wave) is 1, so the signal to interference radio wave ratio (hereinafter abbreviated as D/U) is 1/0.0027, which is 50 dB when expressed in decibels (however, it is a power ratio).

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

The above explanation was from mobile radio m1oo, but
Similarly, calculations can be made for transmissions from the wireless base station 30, and the results are almost the same. However, the wireless base station 30
In the case of transmission from , the usage conditions within the time slot for synchronization signals and control signals differ, and the usage frequency distribution within the time slot differs by this amount, but the effect is small.

(II) Co-channel interference Co-channel interference occurs due to the characteristics of the bandpass filter or intermittent circuit set at the output section of the wireless transmitter circuit, and the higher-order wave of the transmit pulse expressed by equation (9),
That is, this is because a carrier wave whose carrier frequency has 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 enter other time slots, causing co-channel interference.

This influence will be theoretically determined below.

Assume that time slots SD1 and SD2 are used for communication and communication B (Figure 2B (d)).The interference waves that communication A affects communication B can be expressed mathematically using equation (7) as below. It becomes like the expression.

A=Σ m＞　m.

n/((2m+1)π) xsin ((2m+1) π/n) [cos (
(Ω+ (2m+1) p)t+U(t))cos(
(Ω−(2m+1)D)t+U(t))] To specifically obtain equation (16), it is sufficient to perform the same numerical calculation as already performed for equation (1). Therefore, if the characteristic of the filtering circuit included in the wireless transmitting circuit 32 is set to a wide band, then mo is set to, for example, 10000 (1
0Kzx 10000=100KHz> When the value is above, the influence of co-channel interference can be ignored.

In actual turning cakes, this condition can be easily satisfied.

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

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

Of the above, 1ii) is, for example, in the above-mentioned car phone, the distance between transmitting and receiving is at most about 10 KIn (wired section omitted), so 10 touch/300,000 KIn = 1/30 m5ec. A method has been proposed in which the communication area is made into a very small zone with a radius of about 25 m (Ito, "Proposal of a mobile phone system - An approach to ultimate communication", Institute of Electronics and Communication Engineers, Technical Report, C8 Study Group, November 1986, C386). -88 and "'Mobile Telephone System'" Patent Application 1986-64023>.

In the mobile phone system described above, the distance between transmitting and receiving is approximately 100TrL at most (wired section omitted), so 100TIIL/300000KJn= 1/3000
It's mSeC. Therefore, it is negligible compared to ii).

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

In FIG. 6A, the signal speed conversion circuit group 5 of the wireless base station 30
The input to the signal speed conversion circuit 51-1 in 1 is applied as shown in (a), and the speed (pitch) conversion unit is The signal A is compressed to T/n by the signal speed conversion circuit 511 and outputted so that the trailing edge of the compressed signal SA shown in (b) coincides with the trailing edge of the signal SA shown in (C). is output from the wireless transmission circuit 32. The mobile radio m1oo receiving this signal receives the compressed signal @A at the timing shown in (d) at the input of the speed restoration circuit 138, and restores the signal A shown in (a) as shown in (e). It is output to. Here, the delay time τ1 from the leading edge of signal A in (a>) to the leading edge of signal A in (e)
is ding-ding/n. However, the transmission time from the transmitter output section to the spatial transmission section and the receiving section output of the mobile radio device 100 was ignored.

In FIG. 6B, the signal speed conversion circuit 51 of the wireless base station 30
The leading edge of the output signal A compressed to T/n is output to the input signal shown in (a) to -1 at the same time as the trailing edge ends. Therefore, the output of the wireless transmission circuit 32 is (
The mobile radio device 100 that has received this becomes as shown in C).
The input of the speed restoration circuit 138 becomes as shown in (d>), and at the same time as the trailing edge of the compressed signal A, the leading edge of the restored signal A shown in (e) that has been expanded by n times is Therefore, from what is shown in (e), T+T/
A delay time τ2 delayed by n=τ2 occurs.

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

Now, in actual communication, especially in two-way communication such as voice communication, the sender expects a response from the other party, so the delay time needs to be twice τ1 or τ2. Be sure to include the actual numbers. For example, if one time slot (one division) of a transmission signal is T = 1/10 seconds and the time compression coefficient n = 10, then 2 r 1 = 2 x 1 / 10 (11/10
) - 18/100 = 0.18 seconds (180 m seconds) 2 r 2 = 2 x 1 / 10 (1 + 1
/10)-22/100=0.22 seconds (220 msec). On the other hand, the delay time in satellite communication is approximately 250m.
Since it is in seconds, the above value is about the same as in the case of satellite communication. If it is desired to reduce the delay time, it is sufficient to reduce the time slot (one time interval) in the baseband.

That is, by decreasing the lower than the above example, T=1/100
seconds, time compression factor n=100. Then, 2τ1=2X
1/100) (1-1/100) = 2X99/1000
0u0.02 seconds (20ms) 2τ2 = 2x'l/100) (1+1/100) = 2
02/10000==0.02 seconds (20ms>) In a concrete system, for example, the number of time slots allocated to the same mobile terminal within one frame is 10fl.
If time slots for other communications are given cyclically as ii, the above conditions can be met. (
It is sufficient to reduce the time of one frame to 1/10).

The above are the delay times that are inevitably determined by system design, and the delay times for wired systems have 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.

Below we will explain some delay times that may affect the system. 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, so when the radio base station 30 receives a communication signal transmitted (received) from each mobile radio device, Due to different spatial transmission distances, there is a possibility that gaps may occur due to duplication of each time slot.

For example, in the case of a car phone, the mobile radio 100 is near the radio base station 30, and the other mobile radio is in front of the radio base station 3.
If you are at a distance of 10 KIn from 0, the delay time difference is <1/30 m5ec as described above. That is, since the time slot may double by about 0.03 m5ec, it is necessary to provide about 0.05 m5ec as a protection time.

Further, in the case of a mobile phone, in the above example, the distance difference between the two mobile radios and the radio base station 30 is 100 m, so the delay time difference is O,OO03 msec.

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

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

1) Pulse communication of the present invention 1 radio channel with 10 time slots or audio 1
0 channel can be transmitted. The required frequency bandwidth is 3KHz x 10 = 30KHz.By providing a protection band, the required frequency bandwidth is ±4 as shown in Figure 7(a).
Set to 0KH2. This value is somewhat disadvantageous to the present invention, and in reality, such a wide guard band is unnecessary, but this value is used for comparison.

2) In the case of conventional FM communication (one audio channel/carrier wave), the baseband signal of one wireless channel is one audio channel, so the required frequency bandwidth is 3KHz x 1 = 3K.
Hz ±8KH2 is required as a protection band, and the radio carrier spacing is 12°5KHz as shown in Figure 7(b).
(In Japan, this standard is widely used in cordless phones, etc. in the 250MHz/400MHz7 band.)
Therefore, it can be seen that in order to simultaneously transmit 10 channels of audio signals, 12.5 KHz x 10 = 125 KHz is required.

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

Furthermore, when the number of channels (number of simultaneous callers) increases, for example, when comparing 100 voice channels, the required frequency bandwidth for pulse communication of the present invention is (3KHz x l 0
0 +50 (guard band) KHz) x2 = 700KHz In conventional FM communication (SCPC), 12.5KHz do.

Next, let's look at TDMA (
Time Divisin ) laltiple Ac
A comparison will be made between the frequency effective utilization rate when applying cess) to mobile communication and the present invention.

3) For the DMS90 system (References: F,
Lindell et al.”[)digital Ce1lula
r Radio for the1990s”Te
communications P, 254-26.
5 Oct.

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

Therefore, the frequency utilization ratio of the present invention in 1) and the DMS 90 in 3> is 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).

The operation of the mobile radio B1100 described above can be directly applied to the operation of the mobile radio 100B (FIG. 1D).

(3) Application of transmitting/receiving time diversity (1), (
Through the process described in Section 2>, it is possible to make and receive calls between the radio base station 30 and the mobile radio device 100 using diversity using radio channels CH1 and CH2. FIGS. 4C and 4D show a method for applying transmission/reception time diversity with a high layer effect by using other time slots of the same radio channel while
This will be explained using the flowchart shown in the figure. The purpose of applying this type of transmit/receive diversity is to improve the quality of communication, and it is used during low traffic periods when communication time slots are vacant, or when high-speed communication is applied to important subscribers (VIPs). This is done for the purpose of providing quality services.

First, a call must be made from the mobile radio 1100 described in section (1), and the downlink time slot SD1. Using the uplink time slot SU1, the switches 5RA-1-1 and 5R of the switch group 83
B-1-16, 5TA-1-1, and 3TB-1-1 are turned on, and the mobile radio device 100 is communicating with the telephone network 10 via the radio base station 30 and the gateway switch 20. (S251, FIG. 4C). The control unit 140 of the mobile radio device 100 that is already on a call decides to apply diversity using another time slot in the same channel (3252) and searches for an empty time slot in the same radio channel. Start (S253>. The following explanation takes the radio channel CHI as an example, but it can be similarly executed on CH2. Furthermore, the mobile radio device used has the configuration of 100B shown in FIG. 1D.

Now, in order to search for an empty time slot, the speed restoration circuit 138-3 and the speed conversion circuit 131-3 are started to operate, and the timing signal of the timing generator 142 is changed to change the time that is currently used for transmission and reception.・Move time slots other than slots to a state where they can transmit and receive. That is, the timing signal generated by the timing generator 142 changes the on/off method of the transmission/reception on/off controller 123, and the output of the speed restoration circuit 138-3 is set to the second time slot SD2. SD3. ...Sequentially extract the SDn signals and search for an empty time slot 3254N0.3253> If there is an empty time slot, consider using that time slot <3
254>. As a result, for example, the downstream time slot S
When D2 is found to be vacant (254YES)
, a control signal is inserted into the uplink time slot SU1 currently being communicated in a format that does not affect communication, and the wireless base station 3
0 for time slot SD2. A signal requesting the use of SU2 is sent (3255, FIG. 4D).

This signal is received by the radio receiving circuit 35A of the radio base station 30 and transmitted to the control unit 40 (S256). Control unit 4
0, as a result of the investigation, time slot SD2. After confirming that SU2 is unused and necessary, and preparing for its use (
S256), currently used downlink time slot SDI
Insert control signals in a way that does not affect communication using
A desired time slot S for the wireless base station 100
U2 transmits a notification that it is available for use (S257). At the same time, the signal selection circuit 39-2 in the signal selection circuit group 39A of the radio base station 30 and the signal speed restoration circuit 38-2 in the signal speed restoration circuit group 38A are placed in a standby state, and the The signal allocation circuit 52-2 and the signal speed conversion circuit 51-2 in the signal speed conversion circuit [51Δ are also similarly shifted to the standby state.

Mobile radio device 1 receiving a report signal from radio base station 30
00 causes the timing signal of the timing generator 142 to be changed so that in reception, time slots SD1 and SD
2 in a receivable state, and in transmission, time slots SU1 and 5tJ2 are used to transmit the output of the telephone unit 101 to the signal dividing circuit 139 and the speed converting circuit 131-1,
131-3 to the wireless transmission circuit 132-1 (S259>).

On the other hand, at the radio base station 30, the time slot SU1. Since the signal sent using SU2 is received and the control signal confirms that it is a signal from the mobile radio 11100 (3260), the call control unit 81 switches the switches 5RA-1-1, 5R8-
In addition to 1-1, 5TA-1-1, and 5TB-1-1 being in the on state, 5RA-2-1 and 5TA-2-1 are in the on state.
is turned on (Figure 1C) and the call continues (826).
1). Subsequent communications use two time slots for radio channel CH1 and one time slot for radio channel CH2 for both transmission and reception, and transmit/receive diversity (in this case, Communication quality can be further improved by combining the frequency diversity (time diversity) effect explained above.

Also, time diversity can be applied to the radio channel CH2 that is being used by the mobile radio device 100 in the same manner as described above.

In the above explanation, the mobile radio device 100 side takes initiative when applying diversity, but the radio base station 3
The same implementation is possible when 0 is given the initiative.

Furthermore, instead of applying the transmitting/receiving diversity after the call is started as described above, it is also possible to apply the transmitting/receiving diversity from the beginning, which will be explained below.

Taking the case of making a call from the mobile radio device 100 as an example, when transmitting an uplink control signal at the time of a call to the radio base station 30 using time slot S (, In), diversity is applied to the control signal. On the other hand, for the downlink channel of the radio base station 30, a synchronization signal included in an unused time slot is included in the control signal, for example, SDl and SD2. A command signal to use the radio base station 30 is added.By receiving this signal at the mobile radio device 100, the radio base station 30
A control signal indicating that SDI and SD2 are to be used is added to time slot Sun, and this preparation is executed on the mobile radio device 100 side. On the other hand, in the radio base station 30 as well, time slot SU1. Prepare reception at SU2.

After the above preparations, we mutually confirmed that it was possible to carry out the project.

When disconnected, the mobile radio m1oo receives the uplink time slot SU1. If the wireless base station 30 starts transmitting in SU2 and in the downlink time slots SD1 and SD2, diversity can be applied from the start of the call.

Above, we have explained the case of double multiplicity of diversity using two series of time slots in one radio channel, but it is possible to implement it in the same way when the multiplicity is further increased. It is also possible to implement it in combination with frequency diversity using many radio channels.

[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. In addition, when communication traffic is quiet, it is possible to apply frequency and time transmission/reception diversity, so the effects of the present invention are extremely large.

[Brief explanation of drawings]

Fig. 1A is a conceptual block diagram showing the concept of the system of the present invention; Fig. 1B is a circuit block diagram of a mobile radio device used in the system of the present invention; Fig. 10-1, Fig. 1C-2, and Fig. 1cm3. The figure is a circuit configuration diagram showing details of the whole and parts of a radio base station used in the system of the present invention, and FIG. 1D is a circuit configuration diagram of another embodiment of a mobile radio device used in the system of the present invention. FIG. 2A is a time slot structure diagram for explaining the time slot used in the system of the present invention, FIG. 2B is a diagram showing the radio signal waveform of the time slot, and FIGS. 3A and 3B are FIG. 3C is a circuit configuration diagram for multiplexing voice signals and data signals; FIGS. 4A and 4B are flowcharts showing the operation flow of the system according to the present invention; Figures 4C and 4D are flowcharts showing the flow of operations when diversity is applied in this system, Figure 5 is a spectrum diagram for explaining radio wave interference to adjacent channels in this system, and Figures 6A and 4D are 6B
The figure is a timing chart to explain the delay time that occurs in the compression and expansion of signals in this system, Figure 7 is a spectrum diagram to explain the required bandwidth of this system and the conventional system, and Figure 8 is a FIG. 2 is a conceptual configuration diagram for explaining a conventional system. 10... Telephone network 20... Gateway switchboard 22
-1 to 22-n...Communication signal 30...Radio base station 31...Control/call signal processing section 32...Wireless transmitting circuit 35...Radio receiving circuit 3
8... Signal speed restoration circuit group 38-1 to 38-n... Transmission speed restoration circuit 39...
Signal selection circuit group 39-1 to 39-n...Signal selection circuit 40...Control section 1...Clock generator 2...Timing generation circuit 1...Signal speed conversion circuit group 1-1... 51-n...Signal speed conversion circuit 2...Signal assignment circuit group 2-1 to 52-n...Signal assignment circuit 1...Speech path control section 82...ID identification storage section 3
...Switch group 1...Digital encoding circuit 2...Multiple conversion circuit 00.100-1 to 100-n...Mobile radio device 01.
...Telephone unit 20...Reference crystal oscillator 21-1, 121-2...Synthesizer 22-1, 1
22-2...Switch 23...Transmission/reception intermittent controller 31-1, 131-2...Speed conversion circuit 32...Wireless transmission circuit 133...Transmission mixer 34...Transmission section 135...・Radio receiving circuit 36...Receiving mixer 137...Receiving section 138-1, 138-2...
・Speed restoration circuit. 139...Signal dividing circuit 141...Clock regenerator 142...Timing generator 152...Signal mixing circuit 182...ID information collation storage unit.

Claims (1)

[Scope of Claims] 1. Each radio base means (30) each covering a plurality of zones to form a service area; and moving across the plurality of zones and using at least one radio channel to System in mobile communications using each mobile radio means (100) for communicating with a radio base means and barrier exchange means (20) for exchanging communications between said radio base means and said mobile radio means In the radio base means, a plurality of sets of signal speed converting means (51) each converting the speed of a signal separated by a plurality of time slots included in each frame to a high speed, and a plurality of sets of signal allocation means (52) for serially outputting signals in time series at timings allocated to signals separated by a plurality of time slots included in each frame; a plurality of radio transmitting means (32) for transmitting as radio channel radio waves; a plurality of radio receiving means (35) for respectively receiving a plurality of radio channel radio waves sent serially to each frame; a plurality of signal selection means (39) for converting signals separated by the plurality of time slots contained in the plurality of time slots into parallel signals and outputting each signal; and each signal from the plurality of signal selection means. a plurality of sets of signal speed restoring means (38) for converting the signal to a low speed and restoring the signal to obtain each output signal; communication path control means (81, 83) for controlling to apply one signal to be communicated to the slot and controlling to obtain at least one output signal from the plurality of sets of signal speed restoring means; A radio base station for time division communication in mobile communication equipped with 2. each radio base means (30) each covering a plurality of zones to constitute a service area; moving across said plurality of zones and communicating with said radio base means using at least one radio channel; A system in mobile communication using each mobile radio means (100) for exchanging communications between the radio base means and the mobile radio means, wherein the mobile radio means means for determining a plurality of time frames included in each frame in each of the radio channel radio waves transmitted from the radio base means;
At least one time zone separated by slots.
A plurality of wireless receiving means (135, 121-1, 121-2, 122-1, 12
2-2, 123,); and a speed for receiving the output of the wireless receiving means, converting it to a low speed and restoring the signal included in the at least one time slot in each frame into a continuous signal. a restoration means (138); and a plurality of speed conversion means (138) for dividing the signal to be transmitted and converting the speed at high speed in at least one time slot separated by a plurality of time slots included in each frame. 131), and converting the outputs of the plurality of speed converting means into the at least one speed converting means.
A plurality of radio transmitting means (one
32, 121-3, 121-4, 122-3, 122-
4,123) A mobile radio device for time division communication in mobile communication.