JPH05347578A - Time-division communication method for mobile object communication - Google Patents

Abstract

PURPOSE:To provide a mobile object communication system which carries a level-suppressed time difference telephone signal securing the difference from the signal of the precedent frame compressed in terms of time onto a time slot of a frame constitution. CONSTITUTION:Each radio base station 30 is provided to cover plural zones together with each mobile radio equipment 100 which uses a radio channel that put a level-suppressed time difference telephone signal compressed and divided in terms of time onto a time slot of a frame constitution for communication secured to the station 30, and a barrier switchboard 20 which performs the switching of communication among the equipments 100. Therefore the electric power of the time difference telephone signal is extremely reduced and the large multiple load gain is secured. Thus the station 30 and the equipment 100 can decide each transmission level based on the large multiple load gain. Then the transmission power can be reduced and the effective use of frequency is attained.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a system in which a signal having a band characteristic such as a telephone is time-divided / time-compressed and then amplitude-modulated or angle-modulated. The power of the signal is reduced, the level of the signal is increased to a value determined by the difference between the reduced level and the power level originally possessed by the signal, and then the depth of modulation given to the signal by amplitude modulation or angle modulation is increased. The present invention relates to a method in which the signal transmission quality is improved or the wireless transmission power is reduced, and the frequency is effectively used by increasing the depth substantially. More specifically,
A certain wireless channel is given and services are
While one of the many mobile radios in the area is setting up a radio line and communicating with the opposite radio base station,
When another mobile wireless device starts communication with another wireless base station using the same wireless channel, the mobile wireless device and the wireless base station that are in communication with each other due to effective use of frequency or radio wave propagation characteristics. It is intended to provide a method for improving the effective utilization of the frequency by gradually reducing the transmission output, and an economical system using the method, while eliminating the adverse influence on the communication between the two.

[0002]

2. Description of the Related Art In mobile communication using voice to which a small zone method is applied, a method using a time division time compression multiplexed signal is described in the following document.

Reference 1. Ito "Study on mobile phone systems-Proposal of time-division time-compression FM modulation system-" IEICE Technical Report R
CS89-11 July 1989

Reference 2. Ito "Study on mobile phone system-Theoretical study on time-division time-compression FM modulation system"
RCS89-39 October 1989

Reference 3. Ito "Study on mobile phone systems-Study on multipath propagation characteristics of time division time compression multiple FM system-"
IEICE Technical Report RCS89-47 January 1990

Reference 4. Ito "Elucidation of multiple load gain of time division time compression multiple telephone signal and application to FM mobile communication" IEICE Technical Report RCS89-65 March 1990

Reference 5. Hayasaka "Introduction to Acoustic Engineering" Published by Nikkan Kogyo Shimbun, March 1978, pages 21-30

That is, in Reference 1, a transmission signal (baseband signal) is divided into predetermined time interval units and stored in a storage circuit, and when this is read, it is n times faster than the storage speed in the storage circuit. Built in mobile radios and radio base stations to read at a predetermined time slot, angle-modulate or amplitude-modulate a carrier wave with the signal accommodated in this time slot, and to transmit and receive intermittently in time. , 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 applied to the receiving mixer of the radio receiving circuit, and a synthesizer applying to the transmitting mixer of the radio transmitting circuit A circuit is provided, and the output of the synthesizer applied to each is interrupted, and this interrupted state is transmitted and received. For the wireless base station that communicates with each other in an expected manner, the same method as described above for synchronizing the intermittent transmission and reception with that of the mobile wireless device is used, and the receiving side extracts only the signal accommodated in the predetermined time slot. Therefore, by opening and closing the wireless receiving circuit, receiving and demodulating, the signal obtained is stored in the memory circuit, and at the time of reading this, by reading at a low speed of 1 / n of the speed stored in this memory circuit, A system example in which a system that enables reproduction of a transmitted baseband signal, which is an original signal, is constructed has been reported.

Next, in Document 2, the above-mentioned TCM is used.
(Time-division time compression multiplexing) -Adjacent channel interference and co-channel interference, which are problems when the FM system is applied to a small zone, are being studied, and the system can be realized by selecting system parameters appropriately. The possibility is shown.

In Reference 3, the effect of multipath fading that a TCM signal receives during transmission in space is examined, and guard time is set between time slots as a measure for removing or reducing this effect. I suggest you do.

Further, in Reference 4, the multiplex load gain, which has been known to exist in the conventional FDM (frequency division multiplex) signal, has a multiplex load gain similar to that of the FDM signal in the time division time compression multiplex (TCM) system. Reveal that, and
It explains the quantification and operation examples of the system. Then, by using this multiple load gain to deepen the modulation depth of the FM, the transmission power can be significantly reduced, and it is expected that the mobile wireless device can achieve a significant power saving. Has been reported.

In Reference 5, the nature of human voice is described in detail.

FIGS. 14A to 14E show waveforms of vowel sounds a, d, a, o, and u of a voice. The first formant of vowel a in FIG.
z, the second formant is at 2400-3000 Hz. The first formant of vowel D in (b) is 350-55.
0 Hz, the second formant is 1500-2000 Hz,
The third formant is at 2500-3000 Hz, and similarly in the case of the vowel a in (c), 600-800 Hz,
1000-1400Hz, 2700-3100Hz,
In the case of the vowel sound (d), 420-500 Hz, 760-
1000 Hz, 1300 to 2000 Hz, 300 to 480 Hz, 1000 to 1400 H in the case of vowel U of (e)
z, 2000-3000 Hz.

The frequency component that characterizes such a vowel is called a formant. On the other hand, the consonant appears in a transient manner only for a short time, its frequency component is relatively high, and its energy is extremely small. Figure 15 is "CHO"
In the pronunciation waveform of (cho), the part where the amplitude is large and conspicuous is CH
This is the part of the vowel O that follows, and the essential consonant is the fine waveform part that appears at the beginning.

The smallest pronunciational unit that constitutes a word is called a syllable. Most Japanese syllables take the form of (consonant c) + (vowel v), but in foreign languages the structure is complicated and typical syllables are (consonant c) + (vowel v) + (consonant c) Such a structure is adopted. Syllable duration is 100-
At 300 ms, the average is 1/8 second and the inter-syllable pause time is 100-200 ms.

Next, the relationship between the energy of voice and the amount of information will be described with reference to FIG. Even if the peak appearing in the waveform of the voice is compressed and removed, the amount of transmitted information does not change much. On the other hand, if the vicinity of 0 of the voice waveform is removed, the amount of information carried will drastically decrease even if a large amplitude area is left as it is. FIG. 16 shows the results of this experiment, in which the horizontal axis represents the amount of removal of the peak or zero part of the speech waveform, and the vertical axis represents the reduction in word intelligibility caused by such removal.

FIG. 17 clearly shows the removal conditions when the experimental data of FIG. 16 is removed near zero and when the peak is removed. Here, the peak removal amount = 20 log (p ₁ / p ₀ ) (dB) 0 vicinity removal amount = 20 log (p ₂ / p ₀ ) (dB).

[0018]

DISCLOSURE OF THE INVENTION Problems to be Solved by the Invention
In the example of system construction shown in (1), a general description of a mobile communication system using a TCM signal is given, and the system can be constructed by this, but the explanation of multiple load gain is not given. In Document 4, the multiple load gain relating to the signal power of the TCM signal is explained, but when the time-compressed and delimited signal is a telephone signal, the difference signal which is the change with time for each frame. However, it has not been clarified as to the substantial increase in the multiple load gain that can be obtained by using the time-compressed partitioned signal.

Further, in Document 5, the nature of the voice uttered by a person is described in detail, but there is no description about a difference signal which is a temporal change in which a telephone signal is divided into time signals. There is an unsolved problem that a method for effectively utilizing the property is not disclosed.

[0020]

[Means for Solving the Problems] Telephone signals are transmitted to TCM-FM.
At the time of transmission, the telephone signal was compared with the previous frame signal for each frame, and the telephone signal (hereinafter referred to as the time difference telephone signal) extracted by the temporal change in amplitude was temporally compressed and separated. By using a signal, it is possible to obtain a larger multiple load gain than the value that has been clarified so far. In addition, in order to prevent the peaks of the time difference telephone signal from causing interference such as radio interference with other radio channels, a syrabic compressor was added before the amplitude modulator or angle modulator of the radio transmitter. .. As a result, the possibility of the time difference telephone signal affecting other radio channels such as radio interference is eliminated, and the depth of modulation can be substantially increased. It has become possible to obtain. In addition, a bandpass filter, which has the same function as a Syrabic compressor, is inserted in the wireless output stage.

[0021]

14 and 15 show that when the majority of the duration of the telephone signal is divided into short time intervals (for example, 10 ms),
It shows that the same signal is repeated repeatedly. This indicates that when a telephone signal is divided into time signals and a time difference telephone signal that is a time change of the telephone signal is created, the signal often has an extremely small component. When such a time-difference telephone signal is created, there are many cases in which the signal has very few components, so that it is possible to obtain a larger multiple load gain than ever before. That is, in the TCM signal, in addition to the multiple load gain that has been clarified up to now, it is possible to obtain a new gain, which is the load gain of the time difference telephone signal. You can now get

In addition, in order to prevent the peaks of the time difference telephone signal from causing radio interference with other radio channels, a syrabic compressor is added before the amplitude or angle modulator of the radio transmitter. . As a result, the possibility that the time difference telephone signal affects other radio channels such as radio interference is reduced, and the depth of modulation can be made substantially deeper. It is possible to get a gain. Alternatively, a band-pass filter is inserted in the radio output stage to perform an action equivalent to that of a Syrabic compressor, and a large multiple load gain can be obtained. By using the total multiple load gain obtained in this way and increasing the modulation degree of FM (PM) modulation while keeping the interference and the like within the allowable value, it is possible to gradually reduce the transmission output. In addition, the design of the amplifier in the input stage of the modulator becomes easy, and the rated value of the passive circuit such as the mixer, the resistor, and the capacitor can be lowered, and the economical system can be constructed.

[0023]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIGS. 1, 2 and 3 show a system configuration for explaining a basic operation example of the present invention.

In FIG. 1, reference numeral 10 is a general telephone network, and 20 is a gateway switch for switching and connecting the telephone network 10 and a wireless system. Reference numeral 30 denotes a wireless base station, which is an interface with the gateway switch 20, a circuit for converting a signal speed, a circuit for allocating and selecting a time slot,
There is a control part etc., besides setting and releasing the wireless line,
The mobile wireless device 100 (100-1 to 100-n) has a wireless transmission / reception circuit for exchanging wireless signals.

Here, the gateway exchange 20 and the radio base station 30
And the communication lines 22-1 to 22-n including the call signals of the call channels CH1 to CHn and the control signals.

FIG. 2 shows a circuit configuration of the mobile radio device 100 which communicates with the radio base station 30. A received signal such as a control signal or a call signal received by the antenna unit is received by the wireless receiving circuit 13 including the receiving mixer 136 and the receiving unit 137.
5, and the output communication signal is the speed restoration circuit 1
38, the control unit 140, and the clock regenerator 141. The clock regenerator 141 regenerates a clock from the received signal and applies it to the speed restoration circuit 138, the control unit 140, and the timing generator 142.

The speed restoration circuit 138 restores the level (pitch in the case of analog signal) of the communication signal which is the compressed and delimited level-suppressed time difference telephone signal (described in detail later) in the received signal. The suppression is released and the signals are input to the telephone unit 101 and the control unit 140 as continuous signals.

In the communication signal output from the telephone unit 101, the speed conversion circuit 131 divides the communication signal into predetermined time intervals to obtain a level-suppressed time difference telephone signal, and its speed (pitch in the case of an analog signal). Faster (compression)
Then, it is applied to the wireless transmission circuit 132 including the transmission mixer 133 and the transmission unit 134.

The output of the modulator included in the transmission unit 134 is converted into a predetermined radio frequency in the transmission mixer 133,
The signal is transmitted from the antenna unit and received by the wireless base station 30. In order to send a radio signal to the radio base station 30 using the time slot permitted to be used by the mobile radio device 100, the timing information from the timing generator 142 shown in FIG. Must have been obtained.

The timing generator 142 supplies the necessary timing to the transmission / reception interrupt controller 123, the speed conversion circuit 131 and the speed restoration circuit 138 by the clock from the clock regenerator 141 and the control signal from the control unit 140. There is.

The mobile radio 100 further includes synthesizers 121-1 and 121-2 and a changeover switch 122.
-1, 122-2 and changeover switches 122-1 and 122
-2 includes a transmission / reception gating controller 123 and a timing generator 142 that generate signals for switching each of -2, and the synthesizers 121-1 and 121-2, the transmission / reception gating controller 123, and the timing generator 142 are control units. It is controlled by 140. Each synthesizer 121
The reference frequency is supplied to the -1, 121-2 from the reference crystal oscillator 120.

A radio base station 30 is shown in FIG.
N-channel communication signal 22-1 with the gateway switch 20
22 to 22-n are connected to the signal processing unit 31 that forms an interface on the transmission path. Therefore, the communication signals 22-1 to 22-n sent from the gateway switch 20 are transmitted to the wireless base station 30.
Is input to the signal processing unit 31. The signal processing unit 31 includes an amplifier for compensating for transmission loss,
So-called 2-line to 4-line conversion is performed. That is, the input signal and the output signal are mixed and separated, and the input signal from the gateway switch 20 is sent to the signal speed conversion circuit group 51. Further, an output signal from the signal speed restoration circuit group 38 uses the same transmission line as the input signal in the signal processing unit 31 to make the gateway switch 20.
Sent to. Of the above, the input signal from the gateway switch 20 is input to a signal speed conversion circuit group 51 including many signal speed conversion circuits 51-1 to 51-n, is subjected to level suppression, and is divided at predetermined time intervals to obtain a time difference. Get a phone signal,
Receive velocity (pitch) conversion. In addition, the signal transmitted from the wireless base station 30 to the gateway switch 20 is a wireless reception circuit 35.
Is input to the signal speed restoration circuit group 38 via the signal selection circuit group 39, is subjected to speed (pitch) conversion, level suppression is released, and the original telephone signal is restored from the time difference telephone signal to obtain a signal. It is input to the processing unit 31.

The control of the radio receiving circuit 35 or the output of the call signal is performed by the signal selection circuit group 3 including the signal selection circuits 39-1 to 39-n for selecting the signal for each time slot.
9, and the call signals are separated corresponding to each of the call channels CH1 to CHn. This output is restored by the signal speed restoration circuit group 38 including the signal speed restoration circuits 38-1 to 38-n provided for each channel to restore the signal speed (pitch) of the level-suppressed time difference telephone signal, After the signal is restored, it is input to the signal processing unit 31 and subjected to 4-line to 2-line conversion, and then this output is sent to the gateway exchange 20 as communication signals 22-1 to 22-n.

Next, the function of the signal speed conversion circuit group 51 (FIG. 3) will be described. By storing an input signal such as a voice signal or a control signal which is a time difference telephone signal divided into a certain time length in a storage circuit, changing the speed at the time of reading this, and reading at a speed 15 times faster than when storing , It becomes possible to compress the time length of the signal. The principle of time compression of the signal speed conversion circuit group 51 is the same as the case of reproducing a voice recorded by a tape recorder at high speed. In practice, for example, a CCD (Charge Coupled Device) is used.
), BBD (Bucket Brigade Device) can be used, and a memory used in a television receiver or a tape recorder that compresses or expands the time axis of conversation can be used (reference: Kosaka et al. "Conversation" Recorder that compresses / expands the time axis of "Nikkei Electronics, July 26, 1976, 92-133
page).

CCD exemplified by the signal speed conversion circuit group 51
As described in the above-mentioned document, the circuit using BBD or BBD can be used as it is for realizing the time extension function of the signal speed restoration circuit group 38. In this case, the clock and control from the clock generator 41 are used. This can be realized by receiving a timing signal from a timing generator 42 that generates timing according to a control signal from the unit 40 and setting the reading speed to be slower than the writing speed.

The control or voice signal output from the gateway switch 20 via the signal processing unit 31 is input to the signal speed conversion circuit group 51, the time difference signal is obtained, a predetermined level is suppressed, and the speed (pitch) is set. Signal conversion circuit group 5 that allocates signals by time slot after conversion processing
2 is applied. This signal assignment circuit group 52 is a buffer
The memory circuit is a memory circuit that stores the high-speed signals for one segment output from the signal speed conversion circuit group 51, and uses the timing information from the timing generation circuit 42 given by the instruction of the control unit 40 to determine the signals in the buffer memory. reading,
It is sent to the wireless transmission circuit 32. As a result, when the communication signals are viewed as channels, they are arranged in series without overlap in time series, and when all the control signals or call signals described later are implemented, it is as if they were continuous signal waves. become.

The above signals are sent to the wireless transmission circuit 32. The state of this compressed signal will be described with reference to FIG.

The output signals of the signal speed conversion circuit group 51 are input to the signal allocation circuit 52, and time slots are given in a predetermined order. SD in Figure 4 (a)
, SD2, ..., SDn indicate that the speed-converted communication signals are assigned to each time slot. Here, in one time slot, as shown in the drawing, a synchronizing signal and a speech signal or / and a control signal which is a time-difference telephone signal subjected to level suppression are accommodated. If the call signal is not installed, empty slot signal is added to the call signal part only with the synchronization signal,
Alternatively, in some systems, no signal including carrier wave is transmitted. In this way, as shown in FIG. 4A, in the wireless transmission circuit 32, a signal forming one frame in the time slots SD1 to SDn is added to the modulation circuit. The multiplex signals that are time-series to be transmitted are angle-modulated in the wireless transmission circuit 32, and then transmitted to the space from the antenna section.

Regarding the transmission of the control signal between the radio base station 30 and the mobile radio 100 prior to the telephone call when making or receiving a telephone call, regardless of whether the telephone signal is in the band or out of the band. It is possible. FIG. 5 shows these frequency relationships. That is, in the figure (a), an example of the out-of-band signal is shown, and as shown in the figure, the low frequency side (250 Hz) or the high frequency side (3850 Hz) can be used. This signal is used, for example, when sending a control signal during a call. FIG. 5B shows an example of the in-band signal, which is used when making and receiving a call.

Although the above-mentioned examples are all for tone signals, by increasing the number of tone signals or modulating the tones to form subcarrier signals, it is possible to transmit various kinds of signals at high speed. Becomes

Although the above is the case of the analog signal, when the digital data signal is used as the control signal, the voice signal which is the time difference telephone signal of which the level is suppressed is also digitally encoded and both are time-division multiplexed. It is also possible to convert and transmit the data, and the circuit configuration in this case is shown in FIG. In FIG. 6, a voice signal is digitized by a digital encoding circuit 91, and the data signal and the data signal are multiplexed and converted.
This is an example of the case where the signal is subjected to the multiplex conversion by the method and applied to the modulation circuit included in the wireless transmission circuit 32. However, for digital data signals, the analog signal multiple load gain, which will be described later, does not normally exist, so this point must be noted in the system design. Then, if the opposite receiver receives the signal and the demodulation circuit performs the reverse operation to that shown in FIG. 6, the audio signal and the control signal can be separately taken out.

On the other hand, the signal transmitted from the mobile radio 100 is received by the antenna section of the radio base station 30 and input to the radio receiving circuit 35. FIG. 4B schematically shows this upstream input signal. That is, the time slots SU1, SU2, ..., SUn represent transmission signals addressed to the radio base station 30 from the mobile radios 100-1, 100-2, ..., 100-n. Further, the contents of each time slot SU1, SU2, ..., SUn are shown in detail. As shown in the lower left part of FIG. 4B, a call signal or / and a control signal which is a level-suppressed time difference telephone signal. Is made up of. However, the synchronization signal can be omitted depending on the case where the distance between the mobile wireless device 100 and the wireless base station 30 is small or the signal speed.

The control signal of the input signals arriving at the radio base station 30 is immediately added from the radio reception circuit 35 to the control unit 40. However, depending on the size of the speed conversion rate, it is possible to add the signal from the output of the signal speed restoration circuit group 38 to the control unit 40 after performing the same processing as the call signal. The call signal is applied to the signal selection circuit 39. The signal selection circuit group 39 includes a control unit 4
In response to an instruction from the control signal from 0, a timing signal from a timing generation circuit 42 that generates a predetermined timing is applied, and a synchronization signal, a call signal or a control signal is separately output for each time slot SU1 to SUn.

Each of these signals is sent to the signal speed restoration circuit 38.
Is input to. This circuit has a function of performing inverse conversion of the speed conversion circuit 131 (FIG. 2) in the mobile radio device 100 on the transmission side, whereby the original signal is faithfully reproduced and transmitted to the gateway exchange 20. Become.

Hereinafter, an aspect of transmitting the signal space in the present invention will be described by using the required transmission band and the relationship between the transmission band and the adjacent radio channel.

As shown in FIG. 3, the control signal from the control unit 40 is applied to the radio transmission circuit 32 in parallel with the output of the signal allocation circuit 52. However, depending on the size of the speed conversion rate, after the same processing as the call signal is performed, the signal allocation circuit 5
It is also possible to add from the output of 2 to the wireless transmission circuit 32.

Next, also in the mobile radio 100, as shown in FIG.
As shown in FIG. 5, the circuit configuration is required when the communication path among the functions of the wireless base station 30 is one channel.

Original signal, eg voice signal (0.3 kHz-
A frequency distribution of 3.0 kHz) on the output side when passing through the signal speed conversion circuit group 51 (FIG. 3) is as shown in FIG. That is, if the voice signal which is the time difference telephone signal whose level is suppressed as described above is converted 15 times, the frequency distribution of the signal is 4.5 kHz as shown in FIG.
That is, it has been expanded to 45 kHz. Although the frequency distribution of the signal is expanded here, it should be noted that the shape of the waveform simply undergoes a similarity transformation in which the frequency axis is stretched, and the waveform itself does not change. This is necessary when determining the value of the multiple load gain.

Now, FIG. 7 shows a case where the control signal is simultaneously transmitted by using the lower frequency band of the voice signal which is the level-suppressed time difference telephone signal. Of these signals, the control signal (0.2 to 4.0 kHz) and the speech signal CH1 (represented as SD1 at 4.5 to 45 kHz) are assumed to be accommodated in a time slot, for example SD1. Other time slots SD2
The same applies to the audio signal accommodated in SDn.

That is, the time slot SDi (i =
2, 3, ..., N) is a control signal (0.2 to 4.0 kH)
z) and the communication signal CHi (4.5 to 45 kHz). However, the signals in each time slot are arranged in time series, and the signals in a plurality of time slots are not simultaneously applied to the wireless transmission circuit 32.

The above control signal is not implemented when a time slot for the control signal is provided at the beginning of the frame, and when the lower frequency band is used for another signal, the communication signal is not used. Near the frequency band of (4.1 to 4,4
KHz or 46-46.5 kHz).

When these call signals are added to the angle modulation section included in the radio transmission circuit 32 together with the control signal, a required transmission band of at least f _C ± 45 kHz is required. However, f _C is a radio carrier frequency. If there are a plurality of wireless channels given to the system, the speedup of signals by the signal speed conversion circuit group 51 is limited to a certain value due to the limitation of these frequency intervals. F is the frequency interval of a plurality of wireless channels
Let _rep be the maximum signal speed f _H due to the speedup of the audio signal described above, and the following inequality must be established between the two. f _rep > 2f _H On the other hand, in the case of a digital signal, the voice is usually digitized at a speed of about 64 kb / s. Therefore, it is necessary to read the scale of the horizontal axis in FIG. However, the relation of the above equation holds in this case as well.

In addition, the mobile wireless device 100 is connected to the wireless base station 3
The control signal input to 0 is input to the wireless reception circuit 35, part of its output is input to the control unit 40, and the other is sent to the signal speed restoration circuit group 38 via the signal selection circuit 39. .. The latter control signal undergoes speed conversion (conversion to a low speed signal) completely opposite to that at the time of transmission, and then the general telephone network 10
The signal speed is the same as that used in the above, and it is sent to the gateway exchange 20 via the signal processing unit 31.

Next, the operation of making and receiving a call in the basic operation of the system according to the present invention will be described by taking the case of a voice signal as an example.

(1) Calling from the mobile radio 100 This will be described with reference to the flowcharts shown in FIGS. 8 and 9.

When the power of the mobile radio device 100 is turned on, the radio reception circuit 135 of FIG. 2 includes the downlink (radio base station 30 → mobile radio device 100) radio channel (referred to as channel CH1). Start capturing control signals. To this end, the wireless channel (hereinafter referred to as channel CH1) is in the receiving state according to the procedure defined in the system. This is possible by capturing the sync signal in the time slot SDn shown in FIG. 4 (a). The control unit 140 sends a control signal to the synthesizer 121-1 so as to generate a local oscillation frequency that enables reception of the radio channel CH1, and also the switch 122.
-1 is also in a state of being tilted down and fixed to the synthesizer 121-1 side.

Therefore, turn off the handset of the telephone unit 101.
When hooked (beginning of calling) (S201, FIG. 8), the synthesizer 121-2 of FIG. 2 receives from the control unit 140 a control signal for generating a local oscillation frequency that enables transmission of the radio channel CH1. Further, the switch 122-2 is also tilted to the synthesizer 121-2 side to be in a fixed state.
Then, the call control signal output from the telephone unit 101 is transmitted using the radio channel CH1. This control signal is
With the frequency band shown in FIG. 5, this is transmitted, for example, using the time slot SUn.

Now, the call control signal from the mobile radio 100 is properly received by the radio base station 30, and the mobile radio 100
If the ID (identification number) is detected (S202),
The control unit 40 searches for a currently empty time slot. As a result, for example, if the time slot SD1 is vacant, the time slot SDn of the radio channel CH1 is used for the mobile radio device 100 and the time slot uplink (mobile radio device 100 →
The wireless base station 30) SU1 and the corresponding downlink (wireless base station 30 → mobile wireless device 100) SD1 are instructed to be used (S203).

In response to this, the mobile radio 100 shifts to the receivable state in the instructed time slot SD1 and SU1 which is the time slot for the up radio channel corresponding to the down time slot SD1.
(See FIG. 4B) is selected. Mobile radio 1
In the control unit 140 of 00, the transmission / reception interruption controller 12
3 is operated to activate the switches 122-1 and 122-2 (S204). At the same time, a slot switching completion report is sent to the radio base station 30 by using the uplink time slot SU1 (S205), and waiting for a dial tone to be sent (S206).

The radio base station 30 has a time slot S
In addition to U1, SU3 and SUn are included in one frame and transmitted as an upstream signal from another mobile radio 100. The radio base station 30 that has received the slot switching completion report (S207) sends a calling signal together with the ID of the mobile radio 100 to the gateway switch 20 (S20).
8). On the other hand, in the gateway switch 20, the mobile radio 10
The ID of 0 is detected, and a necessary switch of the switch group included in the gateway switch 20 is turned on (S209),
The dial tone is transmitted to the wireless base station 30 (S21).
0, FIG. 9).

This dial tone corresponds to the radio base station 30.
Is transferred to the mobile wireless device 100 (S211), and the mobile wireless device 100 confirms that the communication path has been set (S212).

When this state is entered, the mobile wireless device 100
Since a dial tone is heard from the handset of the telephone section 101, the transmission of the dial signal is started. This dial signal is subjected to speed conversion by the speed conversion circuit 131, and the wireless transmission circuit 13 including the transmission unit 134 and the transmission mixer 133.
From 2, the data is transmitted using the upstream time slot SU1 (S213). Thus, the transmitted dial signal is received by the wireless reception circuit 35 of the wireless base station 30.

The radio base station 30 has already responded to the calling signal from the mobile radio 100, and has set the time
The slot is given, and the signal selection circuit group 39 and the signal allocation circuit group 52 of the radio base station 30 are operated to receive the uplink time slot SU1 and to transmit the downlink time slot SU1.
The state has shifted to transmitting the signal of the slot SD1.
Therefore, the dial signal transmitted from the mobile wireless device 100 is the signal selection circuit 39-1 of the signal selection circuit group 39.
After passing through, it is input to the signal speed restoration circuit group 38, where the original transmission signal is restored and transferred to the gateway switch 20 as the call signal 22-1 via the signal processing unit 31 (S21).
4) The call path to the telephone network 10 is set (S21).
5).

On the other hand, an input signal (initially a control signal, a call signal if a call is started) from the gateway switch 20 is subjected to speed conversion by the signal speed conversion circuit group 51 in the radio base station 30, and then the signal allocation circuit. Signal allocation circuit 52-1 of group 52
Is given a time slot SD1. Then, the time of the downlink radio channel from the radio transmission circuit 32
It is transmitted to the mobile wireless device 100 using the slot SD1.

In the mobile radio 100, the radio channel CH
In the time slot SD1 of No. 1, the reception is awaited, and it is received by the radio reception circuit 135, and its output is input to the speed restoration circuit 138. In this circuit, the original signal on the transmitting side is restored and input to the handset of the telephone unit 101.
Thus, a call is started between the mobile wireless device 100 and the ordinary telephone in the ordinary telephone network 10 (S21).
6).

The end of the call is the telephone section 101 of the mobile radio 100.
By hooking the handset of the mobile phone (S217),
The end signal and the on-hook signal from the control unit 140
The signal is transmitted from the wireless transmission circuit 132 to the wireless base station 30 via the speed conversion circuit 131 (S218), the control unit 140 stops the operation of the transmission / reception interrupt controller 123, and the switches 122-1 and 122- 2 is fixed to the output terminals of the synthesizers 121-1 and 121-2, respectively.

On the other hand, in the control unit 40 of the radio base station 30,
When the call end signal from the mobile wireless device 100 is received, the call end signal is transferred to the gateway switch 20 (S219), the switches of the switch group (not shown) are turned off to end the call (S).
220). At the same time, the signal selection circuit group 3 in the radio base station 30
9 and the signal allocation circuit group 52 are opened.

In the above description, the control signals are exchanged between the radio base station 30 and the mobile radio 100 without passing through the signal conversion circuit group 51, the signal speed restoration circuit group 38, etc., but this is explained. For the sake of convenience, the signal speed conversion circuit group 51 and the signal speed restoration circuit group 38 are the same as those for the audio signal.
Communication can be performed without any trouble through the signal processing unit 31 and the signal processing unit 31.

(2) Incoming Call to Mobile Radio 100 It is assumed that the mobile radio 100 is in a standby state with the power turned on.
In this case, as described in the section of calling from the mobile radio 100, the downlink control signal of the radio channel CH1 according to the procedure defined by the system is in the standby state.

An incoming call signal from the general telephone network 10 to the mobile radio 100 via the gateway switch 20 is transmitted to the radio base station 30.
Suppose you have arrived. Similar to the voice signal, these control signals pass through the signal speed conversion circuit group 51, and are transmitted to the control unit 40 (FIG. 3) through the signal allocation circuit group 52, similarly to the voice signal. Then, the control unit 40 uses the empty slot of the downlink time slot of the radio channel CH1 addressed to the mobile wireless device 100, for example, SD1, to move the mobile wireless device 10
0 ID signal + incoming call signal display signal + time slot use signal (for example, for transmission from the mobile radio 100, S
Use SU1 corresponding to D1). In the mobile wireless device 100 that receives this signal, the signal is transmitted from the receiving unit 137 of the wireless receiving circuit 135 to the control unit 140. Control unit 1
At 40, since it is confirmed that this signal is an incoming call signal to the mobile radio device 100 of its own, the telephone unit 101 sounds a ringing tone, and at the same time, it waits at the instructed time slot SD1, SU1. Transmission / reception intermittent controller 1
23, and switches 122-1 and 12
Turn on and off 2-2. Thus, the call is ready to be made.

It should be noted that the fact that signal transmission is executed in good condition using this system and that it does not adversely affect other radio channels in the system is theoretically explained in Reference 2, and is therefore omitted. However, hereinafter, the effect that the reduction of the power of the time difference telephone signal substantially increases the multiple load gain and the effect of suppressing the peak of the time difference telephone signal will be described.

(3) The effect of reducing the power of the time difference telephone signal Although the multiple load gain in the system which does not use the time difference telephone signal is given by reference 3, the analog telephone signal is divided into the time piece signals as in the present invention. Further, when a time difference telephone signal, which is a difference signal, is created from temporally adjacent time piece signals, and a TCM signal is used in the system, a multiple load gain having a larger value than the conventional value can be obtained. It will be explained below that the utilization of this greatly contributes to the improvement of the effective use of the frequency of the system and the economical efficiency.

Now, referring to the reference 3, the T-multiple
The multiplex load gain (denoted by α dB) of the analog telephone signal (maximum frequency f _h ) converted into CM (frame length T) is given by the following equation. N ′ multiplex FDM (frequency division multiplex)
It is known to be the same as that of signals. n '= n / (2Tf _h )

Next, the features of the case where the TCM signal is generated from the analog telephone signal based on the time difference telephone signal will be described. FIG. 10A is a diagram of FIG.
The signal "a" shown in FIG. 10A is shown, and FIG. 10B shows an example of the time difference telephone signal generated from the signal using the temporally adjacent time piece signals. That is, FIG.
10 vowels "a" of 0 (a) (total time is about 220 ms)
The signal is cut every ms to make a time piece signal, and from these, the same figure (b)
The time difference telephone signals are created and arranged in a line.
However, it is assumed that the pulse noise generated at the time of shifting from one time piece signal to the next time piece signal is removed. Figure 1
4, FIG. 15 and FIG. 10 reveal the following.

1) The amplitude of the time difference telephone signal becomes large only when the short-time amplitude width change of the original telephone signal is large, and the amplitude is extremely small at other times.

2) Since the time length of the time piece signal is about 1 to 30 ms, it is a time length suitable for catching a minute change of the audio signal. As is clear from FIG. 14 and FIG. 15, except for a part of temporally adjacent time piece signals, the signal waveforms thereof are almost the same.

3) Therefore, the following can be generally said as the characteristics of the time difference telephone signal generated by using the temporally adjacent time piece signals. First, 50% or more is almost no signal, that is, an empty signal containing no component. Most of the remaining 50% or less have a small signal power except some.

4) The empty signal has no power, and the power in one frame of the TCM signal obtained by time-compressing the time piece signal containing only a small signal power is as follows. That is, in a frame containing many of these signals, 1
TC that did not create a time difference telephone signal when measuring the average power of each part of the frame every / (2Tf _h ) time
The average power is reduced more than the average power measured every 1 / (2Tf _h ) time of the M signal. This value is estimated to be about 1/10 or less.

Next, the TCM created by the time difference telephone signal
Find the multiple load gain of the signal. To be precise, it is necessary to create a time difference telephone signal similar to that shown in FIG. 10B for many voice signals based on FIGS. 14 and 15 and obtain the distribution or experiment. , Omitted here, and the reduction of the average power of the time difference TCM signal is 9
Reduce by 0% (actually larger). At this time, the multiple load gain is easily increased 10 times (10 dB).

Next, a method of creating the time difference telephone signal described above will be described with reference to FIG. FIG. 11 shows the internal structures of the speed restoration circuit 138, the telephone unit 101 and the speed conversion circuit 131 in the structure of the mobile wireless device 100 shown in FIG.

In FIG. 11, the radio receiving circuit 1 is shown from the right side.
The compressed time difference telephone signal (difference signal) from 35 is input. This input signal is timed by switch 165.
It is input and stored in the telephone signal storage circuit 161-1 or 161-2 for each slot (one for each TCM frame). The terminals a and b of the switch 165 are
The timing of the switching of is performed by a signal from the timing generator 142. The signal stored here is then read out and restored to the original telephone signal rate by the time expansion circuit 162-1 or 162-2. Then, the restored telephone signal is still in the form of a time difference telephone signal, and the telephone signal is generated by switching the terminals a and b of the switch 166-1 or 166-2 (this timing also depends on the signal from the timing generator 142). It is input to the reproduction circuit 163-1 or 163-2. Here, the time difference telephone signal (difference signal) is added to the signal in the time slot of the frame immediately before that, and the original telephone signal for one frame is reproduced. Then, by switching the terminals a and b of the switch 167 (this timing also depends on the signal from the timing generator 142), the output of the telephone signal reproducing circuit 163-1 or 163-2 is taken out alternately, and the telephone unit 10
1 to the receiving circuit 106.

The left side of FIG. 11 shows the internal construction of the telephone section 101, which includes a control section 140 and a telephone control circuit 105.
Control signals are exchanged between the two. Also, the receiving circuit 1
06 and the transmitting circuit 107 operate by receiving a signal from the clock regenerator 141.

The internal structure of the speed conversion circuit 131 is shown in the lower part of FIG. 11, and the telephone signal output from the transmission circuit 107 of the telephone unit 101 is stored in the telephone signal by the switch 175 for each frame of the telephone signal. It is input to the circuit 171-1 or 171-2 and stored therein. The timing of switching the terminals a and b of the switch 175 is performed by a signal from the timing generator 142. The signal stored here is read out and the difference signal generating circuit 172-1 or 172-2 is generated by switching the terminals a and b of the switch 176-1 or 176-2 (this timing also depends on the signal from the timing generator 142). Where the telephone signal is converted into a time difference telephone signal by subtracting (taking a difference) from the telephone signal of the immediately preceding frame. The converted time difference telephone signal is then transmitted to the time compression circuit 1
73-1 or 173-2. Then, by switching the terminals a and b of the switch 177 (this timing also depends on the signal from the timing generator 142), the TCM
The signal is sent to the wireless transmission circuit 132 for each time slot (one is given for each TCM frame unit).

In the radio transmission circuit 132 (FIG. 2), the signal is frequency-modulated at the signal level in consideration of the multiple load gain and then sent to the transmission mixer 133. The TCM-converted telephone signal frequency-modulated by the transmission mixer 133 becomes one modulated signal wave having a designated carrier frequency, and is transmitted from the antenna to the radio base station 30.

Next, the operation of the radio base station 30 will be described. Among the configurations of the radio base station 30 shown in FIG. 3, the internal configurations of the signal speed restoration circuit group 38 and the signal speed conversion circuit group 51 are different from those of FIG. For example, it has substantially the same functions as the speed restoration circuit 138 and the speed conversion circuit 131 of the mobile wireless device 100.

As is clear from the above description, the method for creating the time difference telephone signal is easy, and if it is introduced into an actual system, it is possible to obtain a multiple load gain of about 10 dB or more. It can be used to reduce transmission power.

(4) Peak Suppression Effect of Time Difference Signal by Syrabic Compressor As already described in (3), the time difference telephone signal has its power level (more precisely, a plurality of time difference telephone signals are selected and Since the levels are averaged) are generally low, this has substantially increased the signal's multiple load gain. However, it is generally said that the time difference telephone signal has a low power level, and the power level or peak value of a particular time difference telephone signal is the maximum of the original time piece signal that creates the time difference telephone signal. It has almost the same value as the power level. Also, the maximum peak voltage value of the time difference telephone signal is
It has almost the same value as the maximum value of the original time piece signal. However, when creating a time difference telephone signal, it is assumed that the phases of the main wave components of both signals are matched.

Therefore, as described in (3), the signal is leveled up to a value determined by the difference between the reduced level of the time difference telephone signal and the power level of the original signal, and then the amplitude modulator. Or, if it is added to the angle modulator, there is no particular problem with a normal time difference telephone signal, but with a particular time difference telephone signal, the power level or peak voltage value that it has is large, so it causes adverse effects such as radio interference on other wireless channels. there is a possibility.

The above problem can be eliminated by a silavic compressor (compressor), which is inserted before the amplitude modulator or the angle modulator of the radio transmitter to which the time difference telephone signal is applied. This makes it possible to achieve the purpose.

The operation of the Syrabic compressor will be described below. It is widely used in mobile communication transmitters. On the other hand, the receiver uses a Syrabic expander as a circuit that makes a pair with the compressor, and both are called a Syrabic compander.

Syrabic compander is a general term for a combination of a compressor (compressor) and an expander (expander). What is used in analog voice communication is one that operates according to the envelope level of voice and is currently widely used. Used (Hereinafter, the word syracic is omitted).

In the present invention, a compander similar to the one described above is used to compress and decompress signals in the vicinity of the peak value of the TCM signal and its level to improve the amplitude characteristic. The specific system configuration and operation will be described below.

FIG. 12 shows an embodiment in which a compander is applied to the mobile radio device 100. The difference from the speed conversion circuit 131 shown in FIG. 11 is that the compressor 17 in FIG.
4-1 and 174-2 are difference signal generation circuits 172-1 and 17-2.
It is inserted between 2-2 and the time compression circuits 173-1 and 173-2, where the amplitude of the time difference telephone signal is compressed. An example of the compression characteristic received at this time is shown in FIG.

The compressor characteristic of FIG. 13 gives an output of n ^1/2 with respect to the input signal n, and is therefore called 1/2 compression. That is, when the input level changes by 10 dB, the output level changes by 5 dB. Therefore, the distribution of the amplitude characteristic of the audio signal is 1/2 in decibel. Therefore, when entering the wireless transmission circuit 132, the signal distribution is 1/2 in decibel as compared with the case where the compressors 174-1 and 174-2 do not compress.

Now, assume that the amplitude-compressed signal is transmitted from the radio base station 30 from the antenna and received by the mobile radio 100. 12 is different from the configuration of the speed restoration circuit 138 shown in FIG. 11 in the configuration of the mobile wireless device 100.
And the time-compressed time difference telephone signal of the received signal is the telephone signal storage circuit 16 as described above.
1-1, 161-2, time extension circuits 162-1, 162
-2 and switches 166-1 and 166-2 and then input to the expanders 164-1 and 164-2. This input signal undergoes conversion according to the expander characteristic of FIG. That is, the input level is 5 dB
When it changes, the output level changes by 10 dB. As a result, as shown in the center of FIG. 13, the overall characteristic is that the voice input change on the transmitting side is 1 dB, and the change on the telephone input on the receiving side is also 1 dB.
It becomes dB, and the original signal is reproduced faithfully.

In the above description, the case where the wireless base station 30 transmits and the mobile wireless device 100 receives is explained, but the same applies when the mobile wireless device 100 transmits and the wireless base station 30 receives. That is, also in the radio base station 30, a compander similar to that included in the mobile radio device 100 shown in FIG. 12 is installed at a position corresponding to the insertion position in the mobile radio device 100.

By applying the compander described above, it is possible to eliminate or reduce the possibility that the amplitude of the time difference telephone signal having a large signal level is compressed and adversely affects other radio channels such as radio interference.

As described with reference to FIGS. 16 and 17, it is also known that even if the peak level signal component of the telephone signal is removed, the effect on the intelligibility of the signal is considerably small. Therefore, the compression degree of the compander is large, and its characteristics change over time,
Even if the reproduction of the peak-level signal component becomes unsatisfactory, the influence on the signal is considerably reduced. This is advantageous in increasing the substantial multiple load gain due to the use of companders. That is, it is estimated that the increase of the multiple load gain can be expected to be 10 dB or more in the 1/2 compression, and 15 dB or more can be expected in the 1/4 compression, and it is more advantageous to increase the compression degree.

(5) Peak Suppression Effect of Time Difference Telephone Signal by Band Pass Filter In (4), the peak suppression effect of time difference telephone signal by the compander was explained, but the same effect is inserted in the radio output stage of the signal. It will be described below that it can also be obtained by a bandpass filter according to the present invention. As an example, a TCM signal obtained by multiplexing 10 analog telephone signals converted into time difference telephone signals is taken. In this case, the frequency band of the signal is 3 kHz
.About.30 kHz (the frequency band of the time difference telephone signal is the same). And the carrier frequency of 10 waves is 125
It is assumed that they are arranged at kHz.

This TCM signal is FM, and its modulation deviation amount is 1.75 × 5 = 8.75 rad. (Rms, 10kH
z sine wave). In the above equation, x5 is used because the power reduction of the signal due to the conversion to the time difference telephone signal is utilized for increasing the modulation shift amount. As a result, as described above, in the high-level time difference telephone signal, the frequency shift of the FM modulated signal becomes extremely large. In concrete terms,
Of the effective signal components included in the sidebands of the modulated wave, the approximate maximum frequency f _p is f _p = 30 + 100 = 130 (kHz). Become. To prevent this, a bandpass filter may be inserted in the output stage of the radio modulated wave. The required pass band width B of the band pass filter would then be B = ± 50 kHz.

As a result of inserting the band pass filter, the peak signal component of the time difference telephone signal is suppressed. However, as described above, even if the peak level signal component of the telephone signal is removed,
Since the effect on the intelligibility of the signal is small, there is no problem.

It should be noted that a so-called SCPC (Sing) in which one analog telephone signal is carried on one working carrier frequency is used.
In the le channel per carrier (IDC) method, an IDC (Instanteneous Deviation Control) is inserted before the FM of the signal. This is because when the signal input to the modulator has an excessive level, the level is suppressed to prevent adverse effects such as radio interference on adjacent radio channels. However, since the application of IDC causes distortion noise in the signal, a method of reducing the power level of the signal by creating a time difference telephone signal, such as the method of the present invention, is desirable. Then a compander or bandpass filter should be applied. Of course, these applications also cause distortion noise in the signal, but since the occurrence probabilities of the peak level of the signal are greatly different, the influence on the signal is reduced, and the superiority of the present invention becomes clear.
Of course, the application of IDC is also possible in the present invention.

[0103]

As is apparent from the above description, in the TCM system using the telephone signal, by using the time difference telephone signal described in detail in the text, it becomes possible to further increase the multiple load gain of the TCM signal. , Using it for transmission power reduction not only reduces power consumption but also enables effective use of frequency. Therefore,
The effect of the present invention is extremely large.

[Brief description of drawings]

FIG. 1 is a conceptual configuration diagram showing a concept of a system of the present invention.

FIG. 2 is a circuit configuration diagram for explaining a basic operation of a mobile wireless device used in the system of the present invention.

FIG. 3 is a circuit configuration diagram for explaining a basic operation of a radio base station used in the system of the present invention.

FIG. 4 is a time slot structure diagram for explaining a basic operation used in the system of the present invention.

FIG. 5 is a spectrum diagram showing spectra of a call signal and a control signal.

FIG. 6 is a circuit configuration diagram for multiplexing a voice signal and a data signal.

FIG. 7 is a spectrum diagram showing spectra of a call signal and a control signal.

FIG. 8 is a flow chart showing a flow of basic operation of the system according to the present invention.

9 is a flow chart showing a flow of basic operation of the system according to the present invention together with FIG. 8.

10 is a waveform diagram showing a time difference signal waveform (b) used in the present invention, which is obtained from the signal waveform (a) of FIG.

11 is a circuit configuration diagram showing the operating principle of the speed restoration circuit, the telephone unit, and the speed conversion circuit, which are the constituent elements of FIG. 2;

12 is a circuit configuration diagram of a speed restoration circuit, a telephone unit and a speed conversion circuit in which a compressor and an expander are added to the circuit of FIG.

FIG. 13 is a characteristic diagram showing input / output characteristics of a compressor and an expander.

FIG. 14 is a waveform diagram of a vowel.

FIG. 15 is a waveform diagram of consonant + vowel (cho).

FIG. 16 is a characteristic diagram showing information transmission amount characteristics when peaks are removed from a telephone signal and when the vicinity of 0 is removed.

FIG. 17 is a waveform diagram showing waveforms in the case of removing peaks and the case of removing near zero in FIG. 16;

[Explanation of symbols]

 10 Telephone Network 20 Gateway Switch 22-1 to 22-n Communication Signal 30 Radio Base Station 31 Signal Processing Unit 32 Radio Transmission Circuit 35 Radio Reception Circuit 38 Signal Speed Restoration Circuit Group 38-1 to 38-n Signal Speed Restoration Circuit 39 Signal Selection circuit group 39-1 to 39-n Signal selection circuit group 40 Control unit 41 Clock generator 42 Timing generation circuit 51 Signal speed conversion circuit group 51-1 to 51-n Signal speed conversion circuit 52 Signal allocation circuit group 52-1 ˜52-n signal allocation circuit 91 digital encoding circuit 92 multiplex conversion circuit 100, 100-1 to 100-n mobile radio 101 telephone section 120 reference crystal oscillator 121-1, 121-2 synthesizer 122-1, 122-2 Switch 123 Transmission / reception gating controller 131 Speed conversion circuit 132 Wireless transmission circuit 133 Transmission mixer 134 Transmission unit 135 Radio reception circuit 136 Reception mixer 137 Reception unit 138 Speed restoration circuit 141 Clock regenerator 161-1, 161-2 Telephone signal storage circuit 162-1, 162-2 Time extension circuit 163-1, 163-2 Telephone signal Reproduction circuit 164-1, 164-2 Expander 165, 166-1, 166-2, 167 Switch 171-1, 171-2 Telephone signal storage circuit 172-1, 172-2 Difference signal creation circuit 173-1, 173 -2 time compression circuit 174-1, 174-2 compressor 175, 176-1, 176-2, 177 switch

Claims (2)

[Claims] 1. A radio base means (30), each of which covers a plurality of zones to form a service area, and a frame structure for moving across the plurality of zones and communicating with the radio base means. Mobile communication using barrier exchange means (20) for exchanging communication with each mobile radio means (100) using radio channels carrying time-compressed delimited signals in time slots In the time division communication method, the time-compressed delimited signal is obtained by suppressing the peak level of the difference signal by obtaining a difference signal which is a temporal change for each frame of the time-compressed delimited signal. The time of mobile communication for determining the level of a radio signal used for communication between the radio base means and the mobile radio means on the basis of the multiple load gain obtained as a signal. Split communication method. 2. A radio base means (30) for covering a plurality of zones to form a service area, and a frame structure for moving across the plurality of zones and communicating with the radio base means. Mobile communication using barrier switching means (20) for exchanging communication with each mobile radio means (100) using radio channels carrying time-compressed delimited signals in time slots In the time-division communication method, the multiple load obtained by obtaining a difference signal that is a temporal change amount for each frame of the temporally compressed delimited signal to obtain a temporally compressed delimited signal When determining the level of a radio signal used for communication between the radio base means and the mobile radio means based on a gain,
A time division communication method for mobile communication, comprising a band pass filter for preventing interference to an adjacent radio channel on at least one radio output side of the radio base means and the mobile radio means.