JPH05244072A - Method and system for time-division communication for mobile body - Google Patents

Abstract

PURPOSE:To reduce the transmitter output power and effectively utilize frequencies by effectively utilizing the multiplex load gain where a mixed signal of a digital and an analog time-compressed signal are put in a time slot of frame constitution. CONSTITUTION:The system which uses a gateway exchange 20 for exchanging communications between respective radio base stations 30 and respective mobile radio equipments 100 uses radio channels by putting time-compressed sectioned signals in the time slot of frame constitution. At this time, the analog and digital signals are equalized in level and when respective maximum frequencies are different, the maximum frequencies that signals compressed while time compressibility is varied have are equalized. Then mean electric power in a constant time determined by the maximum frequency is found, increased in level up to the same multiplex load gain, and applied to an angle transmitter for transmission. Consequently, the transmission level can be determined according to a large multiplex load gain to reduce the sending electric power and effectively utilize the frequencies.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to effective use of multiple load gains of a modulated time-compressed multiplex signal in a time division communication method and system of a wireless communication channel in mobile communication. More specifically, a certain wireless channel is provided, and one of the many mobile wireless devices in the service area is used to set up a wireless channel and communicate with an opposite wireless base station. Among, when the other mobile wireless device starts communication with another wireless base station using the same wireless channel, because of effective use of frequency or radio wave propagation characteristics, respectively, with the mobile wireless device during communication, It is intended to provide a method for improving the effective utilization of frequency by gradually reducing the transmission output while eliminating the adverse effect on the communication with the radio base station, and an economical system using the method. Is.

[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 RC
S89-11 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 multiplex telephone signal and its application to FM mobile communication" IEICE Technical Report RCS89-65 Mar. 1990.

Reference 5. Ito "On Co-Channel Interference When Time-division Time-compression Multiplexed Telephone Signal is Applied to Small Zone System" IEICE Technical Report RCS90-7 1990
Month

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 for the opposite purpose, the same method as the above is used to synchronize the intermittent transmission and reception with that of the mobile wireless device, and the receiving side extracts only the signal accommodated in the predetermined time slot. Therefore, the signal received by demodulating by receiving and opening the wireless receiving circuit 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 capable of reproducing a baseband signal which is the transmitted 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.

[0012] Document 5 describes co-channel interference in a radio system using a TCM signal. Among them, when a carrier wave is angle-modulated using a TCM signal, the amount of modulation deviation is increased. , It is described that co-channel interference is reduced to improve the effective utilization of frequencies.

[0013]

DISCLOSURE OF THE INVENTION Problems to be Solved by the Invention
In the system construction example shown in FIG. 1, a general description of a mobile communication system using a TCM signal is given, and the system can be constructed by this, but an explanation of the multiple load gain of a frame-structured TCM signal is given. Not done. Although Document 4 describes the multiple load gain relating to the signal power of the TCM signal,
It is the multiple load gain with respect to the average power of the CM signal, the multiple load gain with respect to the peak voltage is not shown, and the multiple load gain when the signal format includes not only analog but also digital format is explained. There was an unsolved problem that it was not solved.

Further, in Document 5, it is explained that when communication is performed by using a TCM signal, if the modulation deviation amount is increased, co-channel interference is reduced and effective utilization of frequency is improved. However, there is an unsolved problem that there is no description about the processing of the transmission power level and a method for effectively using the transmission power level is not disclosed.

[0015]

In a mobile communication system using a TCM (time division time compression multiplex) signal, as a transmission signal, a time-compressed delimited signal in a time slot of a frame structure is suitable. After amplifying to the level,
Usually, the carrier is modulated in addition to the angle modulator for transmission, further amplified to an appropriate level, added to the antenna, and transmitted. Among these, regarding the level of the signal when added to the transmission angle modulator, conventionally, the average power of the TCM signal existing within the time interval 1 / (2fh) (fh is the highest frequency of the telephone signal) is measured, It was added after leveling up to the multiple load gain of an FDM (frequency division multiplexing) telephone signal having the same average power.

However, the multiple load gain obtained above is obtained from the average power of the signal, and is not obtained from the comparison of the peak voltage of the signal. Furthermore, as the above-mentioned premise, all signals are assumed to be in analog form, and when digital signals are mixed, the additive law of the power of the signals is not clear, and the maximum frequency may be different. , The transmission method when these different kinds of signals were mixed was not clear either.

In the present invention, a method for solving the above problems was theoretically clarified, and a feasible measure was clarified.

That is, it is possible to solve the problem by taking the following method. Before processing each signal, make them have the same level (the signal level fluctuates from moment to moment, but make the average power for a long time the same. Here, the long time means the maximum frequency of the signal is f _h . At this time, the value is sufficiently larger than the time 1 / (2f _h ). By using this as a countermeasure, the peak values of the signals become the same, and the multiplexing gain described later can be obtained.

Before processing each signal, if the highest frequencies they have are different, the time compression ratio is changed so that the highest frequencies the compressed signals have are the same.
As a result, the maximum frequency of the signal after the time compression is the same, and the radio interference to the adjacent radio channel is minimized.

When a time-division multiplexed signal having a frame structure is created by implementing and, the average power within a fixed time (1 / (2f _h )) determined by the highest frequency of the signal is measured, and the average of these is calculated. Ask. If the frame length is smaller than 1 / (2f _h ), this value is
It becomes equal to the average power P _{F of} the multiplex signal (FDM signal) obtained by simultaneously mixing the respective signals simultaneously in the same time.

If the average power of the FDM signal is
Power P _MF assuming that all of the original signals have been voltage-added
In comparison with G _T = 10log ₁₀ P _MF −10log ₁₀ P _F G _T > 0, G _T gives the multiple load gain of the FDM signal and also the multiple load gain of the TCM signal. ..

When the frame length is larger than 1 / (2f _h ), if the correction to be described later is performed, the TC value is the same as that described above.
The multiple load gain of the M signal can be obtained. As a result, when the TCM signal is angle-modulated and transmitted, the modulation level can be increased more than in the past, the transmission power can be reduced, and the frequency can be effectively used.

[0023]

In the TCM signal, the conventionally known multiplex load gain for an analog signal can be used with high precision and large multiplex load gain even for a mixed digital / analog signal. Etc. within the allowable value, the level of the signal applied to the transmission angle modulator can be increased to a value that is conventionally known or higher, the transmission output can be gradually reduced, and the frequency can be effectively used. It was Therefore, the amplifier design becomes easier,
In addition, the rated values of passive circuits such as mixers, resistors, and capacitors can be lowered, making it possible to construct an economical system.

[0024]

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,
It has a wireless transmission / reception circuit for exchanging wireless signals with the mobile wireless device 100 (100-1 to 100-n).

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 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 speed (pitch in the case of analog signal) of the compressed and delimited communication signal in the received signal and inputs it to the telephone unit 101 and the control unit 140 as a continuous signal. ing.

The communication signal output from the telephone unit 101 is transmitted by dividing the communication signal at a predetermined time interval by the speed conversion circuit 131 and increasing (compressing) the speed (pitch in the case of an analog signal) at high speed. Mixer 133 and transmitter 134
And is applied to the wireless transmission circuit 132 including.

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.

The modulation degree and the transmission output level in the radio transmission circuit 132 are determined by an instruction from the control unit 140 in consideration of a multiple load gain described later. To transmit a radio signal to the radio base station 30 using the time slot permitted to be used by the mobile radio device 100, FIG.
It is necessary that the timing information from the timing generator 142 shown in (4) is obtained via the control unit 140.

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 which 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
A 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, the 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, and the gateway exchange 20
Sent to. Of the above, the input signal from the gateway switch 20 is input to the signal speed conversion circuit group 51 including many signal speed conversion circuits 51-1 to 51-n, and the speed (pitch) conversion is performed by dividing the signal speed conversion circuit group 51 at predetermined time intervals. receive. As for the signal transmitted from the wireless base station 30 to the gateway switch 20, the output of the wireless receiving circuit 35 is input to the signal speed restoration circuit group 38 via the signal selection circuit group 39, and the speed (pitch) is converted. It is input to the signal processing unit 31.

The control of the radio receiving circuit 35 or the output of the call signal includes 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 is input, and the call signal is separated corresponding to each call channel CH1 to CHn. This output is input to the signal processing unit 31 after being restored in the signal speed (pitch) by the signal speed restoring circuit group 38 including the signal speed restoring circuits 38-1 to 38-n provided for each channel. 4-line-2
After undergoing line conversion, this output is sent to the gateway switch 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. The input signal such as a voice signal or a control signal, which is divided into a certain time length, is stored in a storage circuit, and the speed is changed when reading the input signal, and the read signal is read at a speed of, for example, 15 times that of the storage time. Can be compressed. 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 a high speed.
CD (Charge Coupled Device), BBD (Bucket Bri
gade Device) can be used, and the 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. “Compressing the time axis of conversation. / Expanding tape recorder "Nikkei Electronics, July 26, 1976, pages 92-133).

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, and the speed (pitch) conversion processing is performed, and then the time slot. It is applied to a signal allocation circuit 52 which separately allocates signals.

The signal allocating circuit 52 is a buffer memory circuit, which outputs 1 signal output from the signal speed converting circuit group 51.
A high-speed signal corresponding to a delimiter is stored in memory, the signal in the buffer memory is read out by the timing information from the timing generation circuit 42 given by the instruction of the control unit 40, and the signal 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 modulation degree and the transmission output level in the wireless transmission circuit 32 are determined by an instruction from the control unit 40 in consideration of a multiple load gain described later. 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 given time slots 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, a synchronizing signal and a call signal or / and a control signal are accommodated as shown in the figure. When the call signal is not installed, an empty slot signal is added to the call signal portion only with the synchronization signal, or in some systems, no signal including the 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 time-serialized 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 call in the incoming and outgoing call of the telephone, either in the band of the telephone signal or out of the band is used. 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 it is desired to send a control signal during a call. FIG. 5B shows an example of the in-band signal, which is used at the time of making and receiving calls.

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

Although the above is the case of the analog signal, when the digital data signal is used as the control signal, it is also possible to digitally encode the voice signal and time-division multiplex both of them for transmission. A circuit configuration in this case is shown in FIG. FIG. 6 shows an example in which the voice signal is digitized by the digital encoding circuit 91, the data signal and the data signal are multiplex-converted by the multiplex conversion circuit 92, 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 sent 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 the 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. The contents of each of the time slots SU1, SU2, ..., SUn are shown in detail in the lower left of FIG. 4 (b) and consist of a call signal and / or a control signal. 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. Further, when the waveform of the radio carrier of the uplink radio signal in the time slot is schematically shown in FIG.
It becomes like (c). Similarly, the transmission waveform from the wireless base station 30 to each mobile wireless device 100 is as shown in FIG.

Now, the control signal of the input signals arriving at the radio base station 30 is immediately added to the control section 40 from the radio receiving circuit 35. However, depending on the size of the speed conversion rate, it is also 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
According to the instruction of 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 according to the present invention will be described with reference to 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, in the mobile wireless device 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-
The frequency distribution on the output side when 3.0 kHz) passes through the signal speed conversion circuit group 51 (FIG. 3) is as shown in FIG. That is, if the audio signal is converted 15 times as described above, the frequency distribution of the signal is as shown in FIG.
It means that the frequency is expanded to 4.5 kHz 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. 8 shows a case where the control signal is simultaneously transmitted using the lower frequency band of the audio signal. Of these signals, control signals (0.2 to 4.0)
kHz) and the speech signal CH1 (represented as SD1 at 4.5-45 kHz) are contained in a time slot, for example SD1. The same applies to audio signals accommodated in the other time slots SD2 to 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 added to the wireless transmission circuit 32 at the same time.

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 applied to the angle modulator 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. The frequency interval of a plurality of wireless channels is f
Let _rep be the maximum signal speed due to the speedup of the above-mentioned audio signal be f _H, and the following inequality must be established between them. 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, from the mobile radio 100 to the radio 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 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 mobile radio device 100 will be described with reference to the flowcharts shown in FIGS. 9 and 10.

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. If the system is provided with multiple radio channels, i) the radio channel showing the maximum received input field ii) the radio channel indicated by the control signals contained in the radio channel iii) Within the radio channel , The wireless channel (hereinafter referred to as channel CH1) is being received according to the procedure defined in the system, such as the channel having an empty time slot. This is the time shown in Fig. 4 (a).
This is possible by capturing the sync signal in the slot SDn. 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 switches 12
2-1 is also in a state of being tilted and fixed to the synthesizer 121-1 side.

Therefore, the receiver of the telephone unit 101 is turned off.
When hooked (start of calling) (S201, FIG. 9), 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. Also, the switch 122-2 is also tilted to the synthesizer 121-2 side to be in a fixed state.
Next, the call control signal output from the telephone unit 101 is transmitted using the radio channel CH1. This control signal is
This is transmitted by means of the frequency band shown in FIG. 5, for example using the time slot SUn.

This control signal is transmitted in the time slot S
It is limited to only Un and is sent in bursts and no signal is sent in other time zones, so that it does not adversely affect other communications. However, if the speed of the control signal is relatively low, or if the amount of information in the signal is large and cannot be accommodated in one time slot, the same time of one frame later or the next frame Sent using slots.

To capture the time slot SUn,
Specifically, the following method is used. As shown in FIG. 4A, the control signal transmitted from the wireless base station 30 includes a synchronization signal and a control signal that follows it. The mobile wireless device 100 receives the synchronization signal and the frame synchronization. It will be possible. In addition, this control signal contains the currently used time slots and the unused time slots (empty time slots).
Control information such as slot display) is included. Depending on the system, time slot SDi (i = 1, 2,
..., n) is being used by another communication,
Sometimes it only contains sync and call signals,
Even in such a case, the unused time slot normally contains a synchronization signal and a control signal, and by receiving this control signal, the mobile radio 100 uses which time slot to issue a call signal. Can be sent.

When all the time slots are in use, it is impossible to make a call on this radio channel, and it is necessary to sweep and search another radio channel.

In another system, an empty slot may not be displayed in any of the time slots. At this time, the audio multiplexed signals SD1 and SD that follow are displayed.
2, ..., SDn must be searched one after another to check for empty time slots.

Returning to the present discussion, the mobile radio 100, which has received the control information sent from the radio base station 30 by any of the above methods, sends out a call control signal at which time slot. Whether or not it should be possible can be determined by including the transmission timing.

Therefore, the time slot SU for the upstream signal
Assuming that n is an empty slot, this empty time slot is used, a call-out control signal is transmitted, a required timing is extracted from a response signal from the radio base station 30, and a burst-like control signal is generated. Can be sent out.

If there is a call from another mobile radio at the same time, the call signal is not properly transmitted to the radio base station 30 due to a collision of calls, and it is necessary to start the operation again from the beginning. However, this probability is suppressed to a sufficiently small value when viewed as a system. If it is desired to reduce call collisions further, the following measures are taken. If mobile radio 100 finds an empty time slot that it can make a call, it does not use all of that time slot, but only the first half for some mobile radios and only the second half for some mobile radios. This is the method to use. That is, as a calling signal, the used portion of the time slot is divided into several types, and using this, a large number of mobile radio devices are grouped, and each group is assigned a time zone within that one time slot. How to give. Another method is to create various types of frequencies that the control signal has, and to assign this frequency to each group by grouping a large number of mobile radio devices. According to this method, even if control signals having different frequencies are simultaneously transmitted using the same time slot, interference does not occur in the radio base station 30. The above two methods may be used separately, or if they are used together, the effect is synergistically increased.

Now, the call control signal from the mobile wireless device 100 is properly received by the wireless base station 30, and the mobile wireless device 100 receives the call control signal.
If the ID (identification number) of is detected (S202),
The control unit 40 searches for a currently empty time slot. The time slot given to the mobile radio 100 may be SUn, but a search is performed just in case. This is because, in addition to the mobile wireless device 100, it is possible to handle simultaneous calls from other mobile wireless devices and to provide time slots suitable for the service type and service classification.

As a result, for example, time slot SD
1 is available, the time slot SDn of the radio channel CH1 is used for the mobile radio device 100 by the downlink control signal (time slot uplink (mobile radio device 10)).
0 → Radio base station 30) SU1, and the corresponding downlink (radio base station 30 → mobile radio 100) SD1 is instructed to be used (S203). In response to this, the mobile wireless device 100 shifts to a state in which it can be received at the instructed time slot SD1 and SU1 which is a time slot for the uplink radio channel corresponding to the downlink time slot SD1 (see FIG. Select b)). At this time, in the control unit 140 of the mobile wireless device 100, the transmission / reception gating controller 123 is operated to turn on the switch 122-1.
And 122-2 are started to operate (S204). At the same time, a slot switching completion report is sent to the radio base station 30 using the uplink time slot SU1 (S205),
Wait for dial tone (S20)
6).

The time of the wireless carrier of this upstream wireless signal
The state of the slot SU1 is schematically shown in FIG. 7 (c). The radio base station 30 has a time slot SU
In addition to No. 1, SU3 and SUn are included in one frame and transmitted as an upstream signal from another mobile radio device 100. Upon receiving the slot switching completion report (S207), the wireless base station 30 sends a calling signal together with the ID of the mobile wireless device 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. 10).

This dial tone is transmitted 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 device 100 to determine the time to be used.
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 upstream time slot SU1 and receive the downstream 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 exchange 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 from the gateway switch 20 (initial control signal, a call signal if a call is started) 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
Has 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 wireless communication circuit 135 is on standby for reception, 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 section 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 device on (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 ends of the synthesizers 121-1 and 121-2, respectively.

On the other hand, in the control section 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 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 the mobile wireless device 100 It is assumed that the mobile wireless device 100 is on standby while the power is 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 transmission from the mobile radio 100, for example, S
(Use SU1 corresponding to D1). In the mobile wireless device 100 that has received this signal, it 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 signal to the mobile radio device 100 of its own, at the same time as making a ringing tone from the telephone unit 101, 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 since it is theoretically explained in Document 2 that signal transmission is executed in good condition using this system and does not adversely affect other radio channels in the system, The theoretical basis of the multiple load gain of the present invention will be described in the following order using the case where all the signals constituting the TCM signal are analog telephone signals.

(3) Comparison of maximum values of peak voltage of TCM and FDM signals (3.1) Voltage value (peak value) of TCM signal and F
Preconditions for comparison with those of DM signal (3.2) Frame length 1/6000 seconds, multiplicity 6000
Comparison of amplitude (peak value) of TCM signal with those of FDM signal at 3.3 (3.3) Frame length 1/3000 seconds, multiplicity 6000
Comparison of the amplitude (peak value) of the TCM signal with that and that of the FDM signal (3.4) TC when the frame length of the TCM signal is 1 second
Comparison of amplitude magnitude (peak value) of M signal with those of FDM signal (3.5) Amplitude magnitude (peak value) of TCM signal when frame length of TCM signal is 1/6000 seconds or less ) And those of the FDM signal (4) Relationship between the multiple load gain of the TCM signal and the multiple load gain of the FDM signal (4.1) With power within 1 / (2f _h ) (1/6000 seconds) Comparison (4.2) Comparison with peak voltage (4.3) Multiple load gain estimation formula of TCM signal (5) Multiple load including analog telephone signal, digital telephone signal and data signal Gain (5.1) Multiple load gain of analog telephone signal 3000, digital telephone signal 3000 multiplex PCM signal (5.2) Analog telephone signal 3000 (maximum frequency is 3
kHz, digital telephone signal 3000 (maximum frequency is 6 kHz) Multiplexed load gain of TCM signal

(3) Comparison of maximum values of peak voltage of TCM and FDM signals (3.1) Voltage value (peak value) of TCM signal and F
Prerequisites for comparison with those of DM signal (i) Configuration of FDM signal FIG. 11 shows a state in which an FDM signal is created from n telephone signals, which will be described with reference to this. n (# 1
~ # N) telephone signals s _i (i = 1, 2, 3, ..., N), and the frequency components of each telephone signal are 0.3 to
It is set to 3.0 kHz. To write the _{formula, s i (t) = Σa} ij sin (ω j t + φ j) (1) Here Σ represents the sum of when the 0.3~3kHz a j, a _ij: configuring the telephone signals Amplitude ω _j of each frequency component: Each frequency constituting the telephone signal φ _j : Phase angle irrelevant to time t.

Further, it is assumed that the average powers are the same for a long period (time sufficiently larger than 1/6000 seconds).

The frequency components of the FDM signal are assumed as follows. # 1 ... 0.3 to 3.0 kHz # 2 ... 3.3 to 6.0 kHz #n ... 0.3 + 3 * (n-1) to 3 * nkHz (the above frequency components are Although it is slightly different from the frequency component of the FDM that has been used conventionally, this assumption was made to simplify the comparison with the frequency component of the TCM signal.)

The above frequency components (for example, n is 600
When it is 0, the frequency component of each telephone signal forming the FDM signal is 0.3 kHz to 18 MHz. When each telephone signal that constitutes the FDM is expressed using a mathematical expression, s _i (t) = Σa _ij sin [{ω _j +3 (i−1)} t + α _j }] (2) where Σ is j. It represents the sum when the frequency is 3 to 3 kHz, and α _j represents the phase angle that is not related to the time t.

The FDM signal is given by a formula in which formula (2) is multiplexed. s (t) = Σ s _i (t) (3) Here, Σ represents the sum when i is an integer of 1 to n (see FIG. 11). Also, according to the sampling theorem, the original signal can be faithfully reproduced if the sampling frequency is 6 × nkHz. The above signals are always present in the time domain.

Further, the FDM signal has no concept of "frame", but when compared with the TCM signal, the expression "frame length or subframe length of the FDM signal" is used. This meaning means the arrangement / state (peak voltage, power) of the FDM signal existing within the same time as the frame length or subframe length of the TCM signal.

(Ii) Structure of TCM Signal FIG. 12 shows a state in which a TCM signal is created from n telephone signals, which will be described with reference to this. The frequency components of each telephone signal that constitutes the TCM signal are assumed as follows. (Each telephone signal is assumed to be the same signal source as in the case of FDM signal) # 1 ... 0.3 × nkhz to 3 × nkhz # 2 ... 0.3 × nkhz to 3 × nkhz …………………… # n ... 0.3 × nkHz to 3 × nkHz Further, the average powers for a long period of time (a time period sufficiently larger than 1/6000 seconds) are equal to each of # 1 to #n. A range (time slot) in which the above signals exist in the time domain (t) is assumed as follows (see FIG. 12). # 1 ... 0 to (1 / n) T, T to (1 + 1 / n) T, ..., mT to (m + 1 / n) T, ... # 2 ... (1 / n) T to (2 / n) T, ((1 / n) +1) T ~ ((2 / n) +1) T,…, (1 / n) + m) T ~ (2 / n + m) T, ……… ……… # n… (1- (1 / n)) T to T, (2- (1 / n)) T to 2T,…, (m- (1 / n)) T to mT,… m is a positive integer.

In an actual system, the following method will be used to mount n telephone signals in each of the above time slots.

First, when a TCM signal is created, the signal is temporarily stored in a memory circuit and then read and arranged sequentially in high speed (n times speed). When t = 0, the signal processing (time compression) of the telephone signal # 1 is performed, and the telephone signal # 1 is mounted in the time slot # 1. Next, telephone signal # 2 is t =
Performs signal processing at 1 / T time, time slot # 2
To be installed on. In the following, the n-2 signals are each 1 in sequence.
It is mounted in time slots # 3 to #n at intervals of / T.
The signal in the #i time slot is expressed as s _i {t- (i-1) T / n} = √n × Σa _ij sin [ω _j n {t- (i-1) T / n} + β _j ] (4) β _j : Phase angle not related to time t Other symbols are the same as in Expression (2).

What can be said from the above is that no power is formed between the TCM signals arranged in each time slot. This becomes important when investigating the peak value of the sample signal generated from the TCM signal. Further, according to the sampling theorem, the TCM signal having the above frequency component can faithfully reproduce the original signal if the sampling frequency is 6 × nkHz.

The right side of the equation (4) is multiplied by √n as compared with the equation (3) because the signal accommodated in each time slot has the same quality as that of the FDM signal. This is because a voltage obtained by multiplying the left side of Expression (1) by √n (n times by power) must be added to one time slot in order to reach the receiving end with.

The above is the method of creating the TCM signal.
In the method of creating the DM signal, it is not necessary to store the frequency component of the signal in the memory circuit except for shifting the frequency component of the signal by a predetermined value.

FIG. 13 shows n telephone signals (# 1 to #).
The crest value of each time slot of the TCM signal is shown when (n) is accommodated in the frame time length (frame length) T by n time slots. n is 6000
The TCM signal at the time is taken as an example and compared with the FDM signal. In this case, the frequency components of the respective telephone signals forming the TCM signal are 1.8 MHz to 18 MHz, respectively.
(See FIG. 12). Each telephone signal having this frequency component is accommodated in the time slots # 1, # 2, ..., #n within the frame time length T = 1/6000 seconds (the time slot interval is 1 / (6000 × n)
Seconds) (Fig. 13).

However, it should be noted that the telephone signal is not time-compressed (compression ratio 1) in the TCM signal having the frame time length T = 1/6000 seconds. That is, to be precise, it is not the TCM signal but the TDM (Time-D
ivision Multiplexing) or PAM (Pulse Amplit)
ude Modulation Multiplexing) signal. However, in order to make a uniform representation including the case where the frame length becomes long, the case where the compression ratio is 1 is also referred to as a TCM signal.

Here, the unit of time for examining the signal characteristics is 1/6000 second. The reason for this is as follows. Faithfully reproduce the original telephone signals by the selected one / the highest frequency f _h of the telephone signal (2f _h). Good agreement can be obtained with the simulation results that have been performed in parallel with the theory.

(3.2) Comparison of amplitude (peak value) of TCM signal with frame length 1/6000 seconds and multiplicity of 6000 and those of FDM signal In FIG. 14, n (= 6000) ) TCM of 1 frame time length (frame length) T = 1/6000 seconds from telephone signals
The crest value (peak voltage) of each time slot when the signal and the FDM signal are created is shown and will be described with reference to this.

The maximum frequency of the TCM signal or the FDM signal is 3 kHz × 6000 = 18 MHz from (3.1) (ii), and the Nyquist frequency f in this case is f = 18 MHz × 2 = 36 MHz.

In the case of TCM signals, the time length of each time signal when converting each telephone signal into TCM is 1/6000 seconds ×
(1/6000) (= 1/36 MHz), and the number of samples contained in one hour piece signal (one time slot) is one, and this is accommodated in each time slot (small frame in FIG. 14). ..

On the other hand, in the FDM signal, signals # 1, # 2 and
, # 6000 combined (mixed) signal Σ = 6000 samples (its peak value is 6000 A) is the same as one subframe (in this case, the frame length is 1/6000 seconds, but the case of the following sections) And the subframe names are used to facilitate comparison). That is, the following signals (samples) are arranged in one subframe. TCM signal: One sample each of the signals # 1, # 2, ..., # 6000 is a time interval (1/6000 seconds) × (1/600)
0) every FDM signal: signal # 1, # 2, ..., # 600
0 (combined) signal Σ = 6000 samples, one sample at a time interval (1/6000 seconds) x (1/600
Every 0)

Regarding the arrangement of signals in subframes, TC
The comparison between the M signal and the FDM signal is performed using FIG.

Each subframe (one frame) includes all the elements (samples) constituting 6000 signals. Since the power is not formed between the sampled signals of the TCM signal existing in the subframe (one frame) as described above, the peak voltage of the FDM signal is compared for each sample.

By using, the time equivalent to 1 time slot (1/36000000 seconds) of the TCM signal and 1 time slot (1/3600000) of the FDM signal is expressed by using.
The peak voltage of the signal within 0 second) is compared.

TCM signals (time slots # 1 to # 600) existing in the subframe (one frame) of FIG.
The peak voltage of the sampled signal within 0) is √6000 to the peak voltage value (A) of one telephone signal.
It is equal to the multiplied value. On the other hand, the FDM signal to be compared with this is a combination of 6000 telephone signals, so its value changes moment by moment, but the maximum peak voltage is when the peak voltages of all telephone signals overlap. Is. At this time,
The peak voltage value is represented by 6000A. As a result, the peak voltage of the TCM signal in each subframe is 1/6000 ^{1/2 of} the FDM signal.

Next, the TCM existing in the sub-frame
The average power of the signals (sampled signals in time slots # 1 to # 6000) is calculated as the FDM signal (telephone channel # 1).
~ # 6000 sampled signal). To do this strictly, the following process needs to be taken. Based on the equations (3) and (4) already obtained, the sum of 6000 telephone signals must be squared and integrated over the time of one frame. However, this has to be quite a tedious calculation, so the following simple method is used.

As shown in FIG. 14, all the telephone signals (600
0) is included, and the amplitude is √6000 of FDM.
On the other hand, in the FDM signal, all telephone signals (600
0) corresponds to the added signal. Therefore, the characteristics of both signals are examined in each time slot unit (each TCM 1 sample, each FDM 1 sample),
Then, it is only necessary to obtain the overall characteristics within these one frame and compare them. Do this below.

First, in the case of the TCM signal, the number of samples existing in one frame is 6000, and each sample is expanded in amplitude of the time-compressed signal of one telephone channel (√6000 times the original signal). ) Is represented. And this amplitude will be normally distributed. Therefore, 60
The average value of the total amplitude of 00 samples is √6 of 1 sample.
Since it increases 000 times, it becomes 6000 times in total. Also, the variance is √6000 times.

On the other hand, the FDM signal takes 1/6000 time.
The number of samples that exist within a second is 6000, and each sample is in a state in which the signal amplitudes of the telephone 6000 channel are mixed. The magnitude of the amplitude of this signal has increased to √6000 times the amplitude of the signal of one telephone channel. And the variance is also √6000 times. Then time 1 /
Examine the overall characteristics within 6000 seconds.

The above-mentioned 6000 samples exist within 1/6000 seconds, but the total amplitude becomes 6000 times √6000 times √6000 times. However, the overall variance will hardly increase from √6000 times. This is because the time of 1/6000 second can be regarded as an extremely short time considering the characteristics of the telephone signal, and therefore the autocorrelation coefficient between samples is high.

As a result of the above examination, it can be considered that the TCM and FDM signals existing in one frame have the same characteristics. This result is important. As the FDM signal multiplicity increases, its average power decreases. This results in multiple load gain. On the other hand, the average power of the TCM signal is FD
This is because when it is equal to the M signal, it also has a multiple load gain, and its value is equal to the multiple load gain of the FDM signal.

(3.3) Comparison of amplitude magnitude (peak value) of the TCM signal and those of the FDM signal when the frame length is 1/3000 seconds and the multiplicity is 6000. In FIG. 15, n (= 6000). ) From two telephone signals, two sub-frames SF1 and S1 having a time length of 1/6000 seconds in one frame time length (frame length) T = 1/3000 seconds.
The peak value (peak voltage) of each time slot when a TCM signal including F2 and an FDM signal are created is shown, and description will be given with reference to this.

A study similar to (3.2) is advanced. TCM
Even when the frame time length T of the signal is 1/3000 seconds, T
The highest frequency that the CM signal has is from (3.1): 3 kHz × 6000 = 18 MHz Further, the Nyquist frequency f in this case is f = 18 MHz × 2 = 36 MHz. Therefore, within 1 frame time length of 1/3000 seconds, each signal # 1, # 2, ...
2 samples each of 0 are signal # 1 and # for the FDM signal.
2, ..., # 6000 synthesized (mixed) signals 2 × 6000 samples are converted into two subframes SF1. SF2
They are evenly arranged within (1/6000 second).
Therefore, the following signals (samples) are arranged in the two subframes SF1 and SF2, for example, in the subframe SF1. TCM signal: time interval (1/6000 seconds) × (1/600) for each two samples of signals # 1, # 2, ..., # 3000
0) in total 6000 FDM signals: 1 sample of combined (mixed) signal of signals # 1, # 2, ...
Every second) × (1/6000), the same comparison as that performed for a total of 6000 (3.2) is focused on one arbitrary subframe.

When the TCM signal is viewed throughout one frame, the same amplitude distribution as (3.2) is shown, but it is greatly different in each of the subframes SF1 to SF2. That is, in subframe SF1
Signals # 1, # 2, ..., # 3000 constituting the TCM signal
And only in subframe SF2, signal #
Only 3001, # 3002, ..., # 6000 are included. On the other hand, the FDM signal contains a composite signal represented as sampled Σ of telephone channels # 1 to # 6000 in an arbitrary subframe.

As a result, in the subframe SF1 and the subframe SF2, the elements (sample signals) forming the respective signals are different from those in (3.2) in FIG. That is, the number has decreased from 6000 to 3000.

TC existing in any subframe
Since the power is not formed between the sampled signals of the M signal as described above, it may be compared with the peak voltage of the FDM signal for each sample.

Now, by using TCM signal, FDM
Comparing the peak voltage of the signal within one sub-frame (1/18000000 seconds) of the signal, as in (3.2), [the peak voltage of the TCM signal in sub-frames 1 to 6000 is 1 times that of the FDM signal]. / (6000)
^1/2 ].

Next, the TC existing in each subframe
The average power of the M signal (sampled signal in time slots # 1 to # 3000 or time slots # 3001 to # 6000) is compared to that of the FDM signal.
If you proceed in the same way as in (3.2), you will encounter the following problems. As shown in FIG. 15, the TCM signal within the time interval of 1/6000 seconds is half as large as that in the case of (3.2).
Only 00 telephone signals are included. Therefore, the above method cannot be adopted, and therefore the average power of the TCM signal is not equal to that of the FDM signal.

However, if the multiplicity of the FDM signals to be compared is reduced to 3000 and this is compared with the above TCM signal, the average powers of both are equal.

(3.4) Amplitude magnitude (peak value) of the TCM signal when the frame length of the TCM signal is 1 second
16 and those of the FDM signal are shown in FIG. 16. In FIG. 16, n sub-frames SF1 to SF with one frame time length T = 1 second from n (= 6000) telephone signals.
The peak value (peak voltage) of each time slot when the TCM signal and the FDM signal including n are created is shown, and the description will be given with reference to this.

In the case where the frame time length of the TCM signal is further increased to 1 second (3.2),
Similar to (3.3), proceed with the study. Also in this case, TCM
One frame of the signal is divided into 6000 subframes (time length 1/6000 seconds). As a result, in conclusion,
You can see the following.

The subframe SF1 includes the signal # 1 forming the TCM signal, the subframe SF2 includes the signal # 2 forming the TCM signal, and the subframe SFi forming the TCM signal includes the signal #i 6000. Each sample will be stored.

On the other hand, the FDM signal has 6000 sample signals of each of the signals represented as combined Σ of the telephone channels # 1 to # 6000 in any subframe. As a result, in subframes 1 to 6000, the elements (sample signals) forming each signal are (3.
Different from 1). That is, it has decreased from 6000 to 1.

As a result of the above, [subframes 1 to 6000
, The peak voltage of the TCM signal is 1/6000 ^1/2 lower than that of the FDM signal].

Next, the TC existing in each subframe
Compare the average power of the M signal (time slot # 1 or # 2, ..., Or the sampled signal of # 6000) with that of the FDM signal. Then, as in (3.3), the following problems are encountered. Looking at FIG. 16, time interval 1
(3.2) for the TCM signal within / 6000 seconds,
Compared to the case of (3.3), only one telephone signal is included. On the other hand, the FDM signal contains 6000 signals. As a result, the following problems occur. A telephone signal with a TCM signal and a high level signal is 1
/ 6000 seconds. This is 1 second when converted before time compression, and there is a high possibility that it will actually occur. On the other hand, the FDM signal contains 6000 telephone signals, and although two or three telephone signals may go high, it is negligible that all signals go high. It is a probability. Therefore, the above method cannot be adopted, and therefore the average power that the TCM signal has is not equal to that of the FDM signal. However, if the multiplicity of the FDM signals to be compared is reduced to 1 and compared with the TCM signal described above, the average powers of the two become equal.

As described above, the time interval is 1/6000.
The meaning of comparing the average powers of both TCM and FDM signals within a second is considered as follows.

Time interval 1 for both TCM and FDM signals
The average power within / 6000 seconds varies variously. For FDM signals, a number of "average power" values are sampled and their distribution is examined. A value 12 dB higher than the mean value of the distribution will give the peak factor.

The characteristics of the distribution of “average power” obtained from the above will be examined. Frame length 1/6 in TCM signal
At 000 seconds, the characteristics of the distribution are FDM as described above.
It matches that of the signal. As a result, if the FDM signal has a multiple load gain, the TCM signal also has the same amount of multiple load gain (same multiplicity). However, when the frame length becomes larger than 1/6000 second, the characteristic of the distribution does not match that of the FDM signal. As a result, the multiple load gain of the TCM signal, if any, will not necessarily match that of an FDM signal with the same multiplicity.

17 and 18 are schematic diagrams showing the instantaneous levels of TCM signals and FDM signals having different frame lengths. In FIG. 17, the frame length of the TCM signal is 1/600
In the case of 0 second, the TCM signal and the FDM signal show the same “average power”.

FIG. 18 shows the case where the frame length of the TCM signal is 1 second, and shows the case where the specific telephone signal of the TCM signal is at the high level. In this case, TCM
The "average power" of the signal is large compared to the FDM signal. Thus, it can be seen that the characteristics of the TCM signal are greatly affected by the frame length.

(3.5) The frame length of the TCM signal is 1 /
Comparison of the amplitude magnitude (peak value) of the TCM signal at 6000 seconds or less with those of the FDM signal The above is the case where the frame length of the TCM signal gradually becomes longer than 1/6000 seconds. In the following, a case where the time is 1/6000 seconds or less (for example, 1/8000 seconds) will be described.

In this case, the sampling frequency of both the TCM signal and the FDM signal is 12 kHz to 16 kHz.
It would be good to change to. As a result, the frame length in FIG. 14 is changed from 1/6000 seconds to 1/8000 seconds, and the description is exactly the same as that given in (3.2).

(4) Relationship between Multiplex Load Gain of TCM Signal and Multiplex Load Gain of FDM Signal In (3.2) to (3.5), the degree of multiplicity was 6000. Comparison with the FDM signal of the peak voltage value or average power of the TCM signal at the time of can be easily analogized. Therefore, hereinafter, the relationship between the multiple load gain of the TCM signal and the multiple load gain of the FDM signal will be obtained. At this time, 1 / {2f _h (1/600
(0 seconds)}, the distinction between the comparison with the power within the power consumption or the comparison with the peak voltage, and further, the change of the multiple load gain depending on the frame time length of the TCM signal will be examined.

(4.1) 1 / {2f _h (1/6000
In the above case, it is easy to find the difference between the multiple load gain G _T of the TCM signal of multiplicity n and the multiple load gain G _F of the FDM signal from the result already obtained in (3). The relationship of G _T1 (n) = G _F (n) (5) is obtained when the frame time length T ≦ 1/6000 seconds.

When the frame time length T of the TCM signal is longer than 1/6000 second, G _T1 (n) = G _F (n ′) (6) where n ′ is a value given by the following equation. use. n ′ = n / (2f _h T) (7) Expressions (6) and (7) have the same contents as Expression (19) in Reference 4. However, it should be noted that the above equation does not consider comparison at peak voltage.

(4.2) Comparison in Peak Voltage The peak value of the FDM signal examined in (3) and that of the TCM signal are TC regardless of the frame time length of the TCM signal.
The peak value of the M signal is 1 / th that of the peak value of the FDM signal.
It was n ^1/2 lower. Therefore, the multiple load gain G _T2 of the TCM signal in this case is G _T2 (n) = 10log ₁₀ n (8)

(4.3) Estimating Multiple Load Gain of TCM Signal From equations (4.1) and (4.2), T of arbitrary frame length is obtained.
The total multiple load gain G _T (n) of the CM signal is obtained. If equations (5) and (8) are independent relations regarding the multiple load gain of the TCM signal, it should be expressed as G _T (n) = G _F (n) + G _T2 (n) (9) Will. However, they are not independent of each other. This is because if the multiple load gain G _{T of} the TCM signal is given by the equation (9), for example, when n = 6000, G _F is 52.
As for 7 dB and G _T2 , a huge multiple load gain of 89.7 dB is obtained as a total of ₁₀ log ₁₀ 6000 = 37.7 dB. Is this really right? In reality this is a mistake. If all the n telephone signals that make up the FDM signal show peak values, then equation (5) becomes G
_F = 0. Therefore, equation (9) becomes 37.7 dB,
This means that the multiple load gain is larger than that of the FDM signal by this value. However, in practice, when the multiplicity n is large, the probability of occurrence when all n telephone signals forming the FDM signal show peak values is small (1% or less), which is a small value. The signal level should be much lower than the peak value. Therefore, the second term on the right side of the equation (9) must not be added, but the total amount cannot be added all the time. Therefore, equation (9) should be considered separately for the following three cases.

I) When T ≦ 1 / (2f _h ), in this case, the multiple load gain of the TCM signal is exactly the same as that of the FDM signal (see FIG. 17). That is, G _T (n)
= G _F (n)

[0139]
(10) ii) When 1 / 2f _h ≦ T ≦ n / (2f _h ), this case is the most difficult. If expressed by a formula, it would be as shown below. G _T (n) = G ₁ (n) + G _T2 (n) (11) G ₁ (n) <G _F (n) (12)

Here, G ₁ (n) cannot be accurately known unless actually measured, but since it is common sense that G _T does not become larger than G _F , G _T = G _F , and the following equation (5) Let's become

First, when T is close to n / (2f _h ), G
_Since there is essentially no significant difference between _T (n) and G _T2 (n), G
₁ (n) cannot take a too large value.

Next, n gradually decreases (especially n
<10), the multiple load gain G _F of the FDM signal gradually decreases, but G _T2 (n) also decreases. When n is further reduced (particularly n <10), the multiple load gain G _F of the FDM signal is greatly reduced, and when n is 3 or less, G
_We have to think that _F = 0. This is because all peak voltages of the telephone signals forming the FDM signal are all likely to overlap at the same time. On the other hand, the peak voltage of the TCM signal is always maintained at 1 / n ^1/2 or less, and the term of ₁₀ log ₁₀ n is significant. Therefore, the expression (12) should be considered as G ₁ (n) ≈0 (n <10), and the expression (11) is only G _T2 (n).

The above is the case where the frame length is 1/6000 seconds, but when it is longer than 1/6000 seconds, it is necessary to use n'obtained from equations (6) and (7).
Therefore, the estimation formula of G _{T is} as follows. G _T (n) = G ₁ (n) + G _T2 (n) (13) G ₁ (n) ≦ G _F (n ′)

[0144] iii) When _{n / (2f h) ≦ T} , in this case, the gain having the G _T is only the G _T2 (n) (see FIG. 18). Therefore, G _T (n) = 10log ₁₀ n

FIG. 19 shows the state of the multiple load gain described in the above i) to iii) when the multiplicity n = 6000. FIG. 19 is a graph of a peak voltage-multiple load gain of a signal in which the frame length T is used as a parameter. When n (n ') is large, when T = 1/6000, G is
_T is shown to match G _F. As T increases, G ₁ decreases accordingly, but G _T2 remains constant. After G ₁ becomes 0, only G _T2 remains. For example, at T = 1/3 second, n ′ = 3, G ₁ (3) = 0, G
_T2 (6000) = 37.7 dB.

[0146] In the above description, the wireless base station 30 side transmits
Of the TCM signal when the mobile wireless device 100 receives it.
It was a multiple load gain that the mobile radio 100 side
The same applies when the wireless base station 30 side transmits
It can be proved that the TCM signal has multiple load gains.
It As described above, each of the tags that make up the TCM signal is
There is a completely independent relationship between the signals in the Im slot,
This is because there is no mutual influence.

The above description has been made on the case where the signal constituting the TCM signal is an analog telephone signal. The multiple load gain of the TCM signal when the digital telephone signal or the data signal is mixed with the analog telephone signal will be described below.

(5) Multiple load gain in the case of including digital telephone signal and data signal in addition to analog telephone signal (4) proved that the telephone signals constituting the TCM signal are all analog signal format. there were.
However, the present is in the ISDN era, and there is a possibility that signals in digital signal formats such as digital telephone signals and data signals (hereinafter referred to as signals include these various signal formats) are mixed in TCM signals. The multiple load gain in this case will be calculated.

As an example, let us consider a case where the radio base station 30 side is transmitting and the mobile radio device 100 side is receiving. It is assumed that the signals input to the signal speed conversion circuit group 51 of the wireless base station 30 of FIG. 3 satisfy the following conditions.

Before processing each signal, its level is set to a magnitude proportional to the highest frequency of the signal (the signal level fluctuates from moment to moment, but the long-term average power is used as a standard. The term "long time" means a value that is sufficiently larger than the time 1 / (2f _h ) when the maximum frequency of the signal is f _h. ) As a result, the peak value of the signal can be Becomes the same,
A multiple load gain of the TCM signal described later can be obtained.

The highest frequencies that analog telephone signals have are well-defined, but less so with digital telephone signals. This is because, in the case of a digital signal type signal, the waveform of the signal is pulse-like, and therefore its spectrum is tailed to a frequency higher. However, in order to clearly determine the multiple load gain of the present invention, it is necessary to clarify the highest frequency that the digital signal has.

Even in a system using a digital signal, the maximum frequency of the signal is usually taken into consideration in the system design, and it is not defined very strictly. That is, of the frequency components of the digital signal, the high frequency components are filtered by the low pass filter. However, the characteristics of the filter are not as severe as those of analog telephone signals.

As an example, the maximum frequency of a 32 kb / s digital telephone signal is about 24 kHz. Frequency components higher than that are filtered by the low-pass filter and are attenuated by about 50 dB. In the present invention, the circuit is designed so that this attenuation is further increased, and it is assumed that even if a frequency component above the maximum frequency is present, the operation of the present invention is not affected at all.

As a result of the above, the maximum frequency of the digital telephone signal is clearly defined similarly to the analog telephone signal, and the description will be continued on the assumption that the frequency components higher than that are completely unnecessary. In the following example, the multiplicity of the TCM signal is set to 6000 and the frame length is set to 1/6000 seconds according to the above-described example.

(5.1) Multiplex load gain of analog telephone signal 3000 and digital telephone signal 3000 multiplex TCM signal The maximum frequency of the frequency components of the analog telephone signal is 3
The maximum frequency of the digital telephone signal is 3 kHz. Although the maximum frequency of the digital telephone signal is higher than 3 kHz at the present technical level, it is the same as the analog telephone signal for simplification, and if different, it will be described later.

Now, it is assumed that each of these signals of 3000 channels is mixed to create a TCM signal. The time compression rate is as follows.

Time 1 for both analog and digital telephone signals
A time piece signal is created in units of / 6000 seconds and these signals are arranged in time series. The time length of the TCM-converted time piece signal is 1/6000 seconds × 1/6000 = (1/6000) ² seconds, and the number of samples included in one hour piece signal (1 time slot) is 1. This is accommodated in each time slot. The maximum frequency of the signal is 3 kHz × 6000 = 18 MHz.

On the other hand, for the same signal as above, an FDM signal is created by the same method as described above, and this and the above T
When compared with the CM signal, the following result is obtained. [The peak voltage of the TCM signal in each subframe is 1 / (6000) ^1/2 of the FDM signal]

Next, TC within 1/6000 second
The average power of the M signal is
We get the following result: a) The average power of the TCM signal is equal to that of the FDM signal. The average power P b) FDM signal, as compared to v _p which gives the maximum peak voltage of each signal constituting the FDM signal, if _{G F = 20log 10 6000v p -10log} 10 P> 0 (14), The value G _F gives the multiple load gain of the FDM signal and at the same time the multiple load gain of the TCM signal. c) The relationship between the above a) and b) is expressed by the equation (5) already described.
Is a formula similar to. d) When the frame length is increased, it is the same as the expressions (11), (12) and (13) already described.

A method of increasing the multiple load gain shown in equation (14) will be described below. For analog telephone signals, the following measures are available.

A) A difference signal is created between adjacent frames, and this is used as a transmission signal.

(A) When the level of the signal to be transmitted is equal to or higher than the average power, the amplitude suppressor is applied (the Siravic compander is one example).

C) A signal with a part of the signal reduced is transmitted.

According to the measures described above, it is necessary to perform another signal processing in addition to the signal processing for TCM conversion from the analog telephone signal. However, if these are simultaneously performed, the signal processing is completed once. It is also possible to let. Therefore, these are effective measures.

The digital telephone signal can achieve its purpose by taking the following method. That is,
When creating a digital signal from an analog telephone signal,
You should pay attention to the following items.

D) Take a long time sample of the analog telephone signal. And the signal of this sample is time 1 / (2
f _h ) (f _h is the highest frequency of the analog telephone signal) is divided as a unit, and the divided time piece signals are grouped by level and the frequency is obtained. However, the number for each group needs to match the number of quantization steps for digitization, and it is assumed that this has been done.

E) The digitized signal is represented by the lowest number of bits for the level having the highest level frequency. That is, it is expressed by 0 bits. Next, the digitized signal for the second highest level is represented by the second number of bits from the lowest. That is, it is expressed by 1 bit. In the following, the digitized signal corresponding to the level having the higher frequency will be expressed with the smaller number of bits. The digitized signal created according to the above method has much lower power than the digitized signal without such measures. However, in the above method, the silent state of the telephone signal was ignored. When the frequency of the silent state is the highest, this is represented by 0 bit, and thereafter, it may be sequentially lowered by 1 bit.

F) In order to effectively use frequencies, telephone signals are often converted into digital signals at low signal speeds. For example, signals of about 10 kbps, and even half-rate signals thereof are emerging. In this case, the signal level of the digital signal itself is calculated as time 1 / (2f _g ) (f
_g is the maximum frequency of the digital telephone signal)
The frequency is calculated, and the signal conversion similar to the above items a) to e) is performed. Alternatively, when a low signal speed digital signal is created from an analog telephone signal, it is possible to complete the signal processing only once by creating a digital signal that exhibits the above effect.

G) After the digital signal processing of the above items e) and f) is performed, the differential signal (a)) used for the analog signal is further implemented.

(5.2) Analog telephone signal 3000 (maximum frequency is 3 kHz), digital telephone signal 3000
(Maximum frequency is 6 kHz) Multiple load gain of multiple TCM signals In the above example, the maximum frequencies of the analog telephone signal and the digital telephone signal are the same. explain. That is, the maximum frequency of the analog telephone signal is 3 kHz, the maximum frequency of the digital telephone signal is 6 kHz, and the number of multiplexed signals is 3000 each. In this case, it is necessary to change the time compression rate so that the highest frequencies of the compressed signals are the same. If this is not done, when this TCM signal is FM-modulated, the sideband of the modulated wave expands, increasing the possibility of causing interference in adjacent radio channels. Therefore, the following measures are taken.

I) The frame of the TCM signal is divided into two subframes, and subframe SF1 is assigned to the analog telephone signal and subframe SF2 is assigned to the digital telephone signal.

Ii) In order to make the maximum frequency of the signal mounted in each time slot after TCM conversion the same, the time compression given to the digital telephone signal should be halved compared to that for the analog telephone signal. There must be. Therefore, the time slot length of a digital telephone signal is twice that of an analog telephone signal.

Iii) To satisfy the condition of ii), assuming that the frame length is 1/18000 seconds, the subframe length of the subframe SF1 is 1/16000.
Second, the subframe length of the subframe SF2 is 1/180
Must be 00 seconds. The frame length is 1 /
The setting of 12000 seconds is to match the multiple load gain of the FDM signal.

Iv) In order to make the average powers of the signals mounted in the respective time slots the same, the power given to the digital telephone signal must be twice the power given to the analog telephone signal.

V) The maximum frequency of the signal is 3 kHz × 12000 = 36 MHz for both analog and digital telephone signals.

By taking the above-mentioned measures, the TCM signal in which analog and digital telephone signals are mixed is F
Even after being processed, it has a signal characteristic with high frequency effective utilization. Below, the multiple load gain of this signal is obtained.

An FDM signal is created for the same signal as above by the same method as described above, and this is compared with the above TCM signal to obtain the following result. [The peak voltage of the TCM signal in each subframe is 1 / (6
000) ^1/2 ]

Next, T within the time 1/12000 seconds
The average power of the CM signal is as follows compared to that of the FDM signal.

A) The average power of the TCM signal is equal to that of the FDM signal. The average power P b) FDM signal, as compared to v _p which gives the maximum peak voltage of each signal constituting the FDM signal, if _{G F = 20log 10 6000v p -10log} 10 P> 0 (15), The value G _F gives the multiple load gain of the FDM signal and at the same time the multiple load gain of the TCM signal. The expression (15) is similar in shape to the expression (14), but the content is slightly different. If the analog telephone signal is the only one, the equation (15) completely matches the equation (14), but since the digital telephone signal in which the power reduction due to the addition of the signals is small is included, the equation (15) is Formula (14)
This is the point where the obtained value becomes smaller.

Next, the case where the frame length becomes longer than 1/18000 seconds will be described. First, as described above, the case where the frame length becomes sufficiently large and only G _T2 is obtained as the multiple load gain of the TCM signal will be obtained. In this case, the frame length is given by 3/8 seconds and the formula corresponding to formula (8) becomes _{G T2 = 10log 10 6000 (16} ).

The multiple load gain when the frame length is longer than 1/12000 seconds and shorter than 3/8 seconds will be described below. It can be obtained by interpolating the multiple load gains obtained from equations (15) and (16).

In the above example, the analog and digital telephone signals are mixed, but even when general data signals are mixed, the multiple load gain can be similarly obtained. Also, a measure for increasing the multiple load gain is possible as in the above.

[0183]

From the above description, it has been clarified that the signal on the transmission side of the TCM-converted telephone signal has a larger multiple load gain than the multiple load gain that has been clarified in the past. Further, even if the signal format of the telephone signal forming the TCM signal exists separately from analog and digital, or even if the data signal is mixed therein, a method for obtaining the multiple load gain of the TCM signal is provided. Since it was clarified, it became possible to construct the system accurately even if the parameters of the system design were varied more than before. Therefore, it is possible to increase the level of the signal applied to the transmission angle modulator to a value that is conventionally known or higher, while keeping the interference and interference within the allowable value, and it is possible to reduce the transmission power and frequency. It became possible to effectively use.

Further, the amplifier can be easily designed, and the rated values of passive circuits such as mixers, resistors and capacitors can be lowered, and an economical system can be constructed.
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 function of a time slot 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 waveform diagram showing a radio signal waveform of a time slot.

FIG. 8 is a spectrum diagram showing spectra of a call signal and a control signal.

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

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

FIG. 11 is a spectrum diagram when an FDM signal is created from n telephone signals.

FIG. 12 is a spectrum diagram when a TCM signal is created from n telephone signals.

FIG. 13 is a time slot diagram in which n telephone signals are accommodated in n time slots.

FIG. 14: 1 frame time length 1/6 from n telephone signals
FIG. 6 is a peak value diagram showing peak values of time slots when a TCM signal and an FDM signal of 000 seconds are created.

FIG. 15 is a diagram showing a TCM signal and an FD each of which has 1 subframe of 1/3000 seconds and includes 2 subframes from n telephone signals.
FIG. 6 is a peak value diagram showing peak values of time slots when an M signal is created.

FIG. 16 is a peak value diagram showing peak values of time slots when a TCM signal and an FDM signal having a one-frame time length of 1 second including n sub-frames are created from n telephone signals.

FIG. 17 is a level diagram showing an example of instantaneous levels of an FDM signal and a TCM signal having different frame lengths.

FIG. 18 is a level diagram showing another example of instantaneous levels of FDM signals and TCM signals having different frame lengths.

FIG. 19 shows TC when the frame length T is used as a parameter
It is a multiple load gain figure which shows the multiple load gain of an M signal, and the multiple load gain of an FDM signal.

[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 .About.52-n signal allocation circuit 91 digital encoding circuit 92 multiplex conversion circuit 100, 100-1 to 100-n mobile radio device 101 telephone unit 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 Transmitter 135 Radio receiver circuit 136 Receive mixer 137 Receiver 138 Speed recovery circuit 141 Clock regenerator

Claims (4)

[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 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, when the format of the temporally compressed delimited signal is composed of a mixed signal of a digital signal and an analog signal, the digital signal of the temporally compressed delimited signal is obtained. The multiple load gain obtained by setting the time compression ratio so that the maximum frequencies of the signals and the analog signals are made substantially equal. And Zui, a time division communication method in a mobile communication defining the level of the transmission signal between the radio base unit and the mobile radio unit. 2. The power of a multiplexed signal obtained by simultaneously temporally mixing the digital signal and the analog signal before time compression is reduced as compared to the power given by the sum of the peak voltages before the time compression. In the case of a divided value obtained by temporally compressing each of the digital signal and the analog signal in the time slot of the frame structure, based on the reduced value. 2. The time division communication method for mobile communication according to claim 1, wherein the level of the transmission signal is determined by a determined multiple load gain. 3. The level of the transmission signal is determined so that when the digital signal is created from an analog signal, the power of the digital signal is as low as possible. Time division communication method for mobile communication. 4. 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 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 system, when the format of the temporally compressed delimited signal is composed of a mixed signal of a digital signal and an analog signal, the digital signal of the temporally compressed delimited signal is The multiple load ratio obtained by setting the time compression ratio so that the maximum frequencies of the signal and the analog signal are substantially equal. Transmission means which is determines a transmission power level based on (132,3
2) A time division communication system for mobile communication, comprising at least one of the radio base means and the mobile radio means.