JPH05235841A - Time division communication method for mobile body communication - Google Patents

Abstract

PURPOSE:To reduce transmission power and to utilize the frequency effectively by applying processing to shift a frequency component of a telephone signal to a lower frequency and implementing signal processing for TCM processing. CONSTITUTION:A frequency band of a signal of each communication is shifted to a lower frequency and divided into a low frequency signal and a high frequency signal. Then, the low frequency signal is blocked at a prescribed time interval to form a low frequency time piece signal, a broad band signal is subject to frequency conversion to set the same frequency range as the frequency range of the low frequency signal thereby generating a low frequency processed high frequency time piece signal. Then, the low frequency time piece signal and the low frequency processed high frequency time piece signal are alternately superimposed on a time slot of frame structure and communication is implemented between a radio base station 30 and mobile radio equipment 100-1-100-n. Since the multiplex load gain of the time division time compression multiplex (TCM) signal is increased and the carrier interval is made narrow, the transmission power is reduced and the frequency is effectively utilized.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a time division communication method of a wireless communication channel in mobile communication using a signal having a band characteristic of a telephone or the like, by shifting a frequency component of a transmission signal to a low band, The present invention relates to a method for increasing the multiple load gain of a signal, reducing the transmission level, and narrowing the interval between wireless carrier waves to improve the effective use of wireless frequencies. More specifically, a radio channel is provided and used by one of the many mobile radios in the service area.
Effective use of frequency when another mobile wireless device starts communication with another wireless base station using the same wireless channel while communicating with the opposite wireless base station by setting a wireless line. For the reasons above or due to the radio wave propagation characteristics, the adverse effects on the communication between the mobile wireless device and the wireless base station during communication are eliminated in advance, and at the same time the transmission output is gradually reduced and the wireless carrier interval is narrowed. It is intended to provide a method for improving effective utilization of frequency by doing so and an economical system using the method.

[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.

That is, in Reference 1, a transmission signal (baseband signal) is divided into predetermined time interval units and stored in a memory circuit, and when reading this, the speed is n times faster than the speed of storing in the memory 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.

Further, 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 FDM (frequency division multiplex) signals in the past, has a multiplex load gain similar to 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.

[0011]

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 although the system can be constructed by this, a frequency component of a telephone signal is shifted to a low frequency band. This is a case where TCM is performed without performing processing such as the above, and the merit obtained by shifting to the low frequency band has not been described. Reference 4
Although the multiple load gain relating to the signal power of the TCM signal is described in the above, the above processing is not performed on the time-compressed segmented signal in the frame-structured time slot, and thus the low load gain is obtained. The technology and merits of shifting to the realm were not clarified, and unsolved problems remained.

[0012]

In a mobile communication system using a TCM (time division time compression multiplex) signal, after performing processing such as shifting a frequency component of a transmission signal (telephone signal) to a low frequency band. , Decided to perform signal processing for TCM conversion. As a result, it is possible to increase the multiple load gain of the signal and reduce the transmission level.

Further, the frequency components of the temporally compressed delimited signal are also shifted to the low frequency band by using the frequency shifter, and the occupied bandwidth of the frequency of the modulated wave angle-modulated by using this is shifted. As a result, it becomes possible to reduce the wireless carrier wave spacing and improve the effective utilization of wireless frequencies.

Furthermore, it is possible to suppress the mixing of noise to such an extent that even if only the partial information is transmitted by paying attention to the characteristics of the telephone signal without transmitting the entire signal (telephone signal) to be transmitted. It is possible. By combining this method and the above method, it is possible to further increase the multiple load gain of the signal and at the same time improve the effective use of the frequency.

[0015]

In the communication using the TCM signal, a large number of telephone signals are disconnected as transmission signals at fixed time intervals (this is called a time piece signal), and this is, for example, 10 times.
In the case of multiplexing, it is compressed ten times in time and arranged at the position of the time slot number given to each of the 10 time slots prepared in the frame structure.
In a normal case, these compressed signals are applied to a transmission angle modulator to modulate a carrier wave, which is amplified to an appropriate level and then added to an antenna for transmission. This is amended as follows. That is, each of a large number of telephone signals, which are transmission signals, is subjected to a process of shifting the frequency components of the telephone signals to low frequencies, and then cut at regular time intervals. The subsequent processing is the same as the usual method.

As a result, the following operational effects were obtained. 1) The multiple load gain shown in Reference 4 is higher than the conventional one because the maximum frequency included in the telephone signal is decreased.

2) The frequency components of the temporally compressed delimited signal are also shifted to the low frequency band, and the occupied bandwidth of the frequency of the angle-modulated modulated wave is reduced by using this, and the radio carrier wave is reduced. It has become possible to reduce the interval, improving the effective utilization of radio frequencies. Also, TC
Even if not all the signals to be transmitted (telephone signals) are transmitted as the M signal and only some information is transmitted by paying attention to the characteristics of the telephone signal, it is possible to suppress the mixing of noise to a negligible level. It is possible. For example, in the case of 10 multiplexes, it is 1 in terms of time.
It will compress by a factor of 0 and send all of these compressed signals in order, but if this is for example removed instead of sending all the frequency components of the signal being added to the time slot, For example, of the frequency components of a signal, the lower half is transmitted first, then the upper half, and so on. After converting to a lower frequency, I decided to transmit. As a result, the following operational effects were obtained.

3) The multiple load gain shown in Document 4 increases by 3 dB from the conventional one because the power contained in the signal is reduced by half.

4) The highest frequency contained in the signal is 1
Since it becomes / 2, it is possible to obtain the advantage that it is equal to the multiple load gain of the FDM signal having the multiple load gain that is twice that of the conventional one. Based on the above results, it becomes possible to improve the effective utilization of frequency by the following measures.

5) The highest frequency contained in the signal is 1
Since it becomes / 2, the carrier frequency interval can be reduced to about 1/2 of the conventional one.

Among the above advantages, an increase in multiple load gain,
The improvement of the effective utilization of frequency will be described later in detail. However, regarding the signal quality, since the signal to be transmitted is partially deleted before transmission, the quality of the received signal may naturally deteriorate. However, when the time piece signal is created, the deterioration amount can be minimized depending on the time length.
According to the experimental results of the inventors of the present application, 1/3 of the frequency component of the signal to be transmitted, that is, the frequency components of the time slot signals arranged in time are divided into three equal parts, upper, middle, and lower,
It has been clarified that the deterioration of signal quality is within the practically permissible limit even if these are transmitted in order.

[0022]

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

In FIG. 1, 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 restoring circuit 138 restores the speed (pitch in the case of an 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 divided by the speed conversion circuit 131 at predetermined time intervals, and the speed (pitch in the case of an analog signal) is increased (compressed) and transmitted. 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. In order 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, the timing information from the timing generator 142 shown in FIG. Must have been obtained by

The timing generator 142 supplies necessary timings 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 is performed by the signal selection circuit group 3 including the signal selection circuits 39-1 to 39-n for selecting the signal for each time slot.
9 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 the signal speed conversion circuit group 51 is
This is the same as playing back the sound recorded by a tape recorder at high speed. In practice, for example, CCD (Char
ge Coupled Device), BBD (Bucket Brigade Devic)
e) can be used, and a memory used in a television receiver or a tape recorder for compressing or expanding the time axis of conversation can be used (reference: Kosaka et al. “Compress time axis of conversation / Expanding Tape Recorder Nikkei Electronics July 26, 1976
92-133).

CCD exemplified by the signal speed conversion circuit group 51
The circuit using the BBD or BBD can be used as it is for the signal speed restoration circuit group 38 as described in the above document. In this case, the clock from the clock generator 41 and the control signal from the control unit 40 are used. By receiving the timing signal from the timing generator 42 that generates the timing, the read speed is set lower than the write 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 is set. 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 state of this compressed signal will be described with reference to FIG.

The output signals of the signal speed conversion circuit group 51 are input to the signal allocation circuit 52, and time slots are given in a predetermined order. SD in Figure 4 (a)
, SD2, ..., SDn indicate that the speed-converted communication signals are assigned to each time slot. Here, in one time slot, 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 telephone call when making or receiving a telephone call, regardless of whether the telephone signal is in the band or out of the band. It is possible. FIG. 5 shows these frequency relationships. That is, in the figure (a), an example of the out-of-band signal is shown, and as shown in the figure, the low frequency side (250 Hz) or the high frequency side (3850 Hz) can be used. This signal is used, for example, when 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.

When the frequency component of the telephone signal is shifted to the low frequency band, it becomes difficult to use the control signal shown in FIG. 5 (a) in the low frequency band of the telephone signal.
In the case of the in-band signal form shown in (b), or when used in the same time slot, the telephone signal and the control signal are used while being temporally shifted.

In the above examples, tone signals are used. However, by increasing the number of tone signals or by modulating the tones to form subcarrier signals, various types of signals can be transmitted at high speed. Becomes

Although the above is the case of the analog signal, when the digital data signal is used as the control signal, 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 transmitted from the mobile radio 100 is received by the antenna section of the radio base station 30 and input to the radio receiving circuit 35. FIG. 4B schematically shows 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 from the radio receiving circuit 35 to the control unit 40. 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.

Further, from the mobile radio device 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 with reference to the case of a voice signal.

(1) Calling from mobile wireless device 100 This 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, in the radio reception circuit 135 of FIG. 2, the radio channel is included in 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, turn off the handset of the telephone unit 101.
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, there is a case where an empty slot is not displayed in any time slot. 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 transmitted from the radio base station 30 by any one of the above methods, transmits the call control signal at which time slot. Whether or not it should be possible can be determined by including the transmission timing.

Then, 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 another mobile radio device makes a call at the same time, the call signal is not properly transmitted to the radio base station 30 due to a call collision, and it is necessary to restart the operation 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 corresponds to the radio base station 30.
Is transferred to the mobile wireless device 100 (S211), and the mobile wireless device 100 confirms that the communication path has been set (S212).

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

The radio base station 30 has already responded to the calling signal from the mobile radio 100, and has set the time
The slot is given, and the signal selection circuit group 39 and the signal allocation circuit group 52 of the radio base station 30 are operated to receive the 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 (initial control signal, a call signal if a call is started) from the gateway switch 20 is subjected to speed conversion by the signal speed conversion circuit group 51 in the radio base station 30, and then the signal allocation circuit. Signal allocation circuit 52-1 of group 52
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 unit 40 of the radio base station 30,
When the call end signal from the mobile wireless device 100 is received, the call end signal is transferred to the gateway switch 20 (S219), the switches of the switch group (not shown) are turned off to end the call (S).
220). At the same time, the signal selection circuit group 3 in the radio base station 30
9 and the signal allocation circuit group 52 are opened.

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

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

An incoming call signal from the general telephone network 10 to the mobile radio 100 via the gateway switch 20 is transmitted to the radio base station 30.
Suppose you have arrived. Similar to the voice signal, these control signals pass through the signal speed conversion circuit group 51 and are transmitted to the control unit 40 (FIG. 3) through the signal allocation circuit group 52, similarly to the voice signal. Then, the control unit 40 uses the empty slot of the downlink time slot of the radio channel CH1 addressed to the mobile wireless device 100, for example, SD1, to move the mobile wireless device 10
0 ID signal + incoming call signal display signal + time slot use signal (for 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 it is theoretically explained in Reference 2 that signal transmission is executed in good condition using the present system and does not adversely affect other radio channels in the system. Theoretical proof of multiple load gain in telephone signal and its application are also described in reference 4, so they are omitted and the TCM applied to the present invention is described below.
A method of increasing the multiple load gain of the system and improving the effective frequency utilization will be described.

(3) Theoretical explanation of increase in multiple load gain The multiple load gain obtained by converting a telephone signal into TCM is given by the following formula when expressed by using the formula shown in Reference 4. Equal to the multiple load gain with the multiplicity n '. n ′ = n × (2f _h T) ^−1/2 (1) where n is the multiplicity of the TCM signal, f _h is the highest frequency of each telephone signal constituting the TCM signal, and T is 1 of the TCM signal.
It is the time of the frame.

As is clear from the above equation (1), when f _h is small, n'is generally large, and therefore TC
The multiple load gain of the M signal is increased. For example, if the frequency band of the telephone signal is 0.3 to 3.0
The frequency band is set to kHz, and this frequency band is shifted to the low frequency band of 0.2 kHz. As a result, the maximum frequency of the telephone signal is 3.
It goes from 0 kHz to 2.8 kHz. Therefore, n '
Is increased by 7%. Then, since the increase of the multiplex load gain is related to the number of multiplexes, it cannot be said to be the case, but it increases about 0.3 dB around n ′ = 100. Although this value is not a large value as an increase in the multiple load gain, it is considered to be a satisfactory value in terms of the system in view of the effect of narrowing the radio carrier interval described below.

The frequency band of the telephone signal is 0.
A circuit that shifts to a low frequency band of 2 kHz is known and can be easily realized.

Further, all frequency components of the signal added to the time slot are not transmitted, but are partially deleted, for example, among the frequency components of the signal, first the lower half and then the upper half are alternated. , And before transmitting the upper half, it is converted to the same low frequency as the lower half that was transmitted first by frequency conversion, and then transmitted, as is clear from Equation (1). And f _h is 1/2
Therefore, when the values of the other parameters are constant, n ′ is doubled.

Further, it will be explained that by further shifting the frequency band of the telephone signal to the low frequency band and deleting a part of the transmission signal, it is possible to further increase the multiplex load gain. .. As an example, first, a process of shifting a frequency component of a transmission signal (telephone signal) to a low frequency band of 0.2 kHz is performed. Next, in the frequency component of the signal, the lower half first, then the upper half, and so on are alternately transmitted.Before the upper half is transmitted, this is converted to the lower half that was transmitted first by frequency conversion. After converting to the same low frequency, after performing processing such as time compression, it is added to the angle modulator.

The maximum frequency of the telephone signal shifts from 3 kHz to 2.8 kHz, and is further reduced to 1/2, which is 1.4 kHz. As a result, there are two types of multiple load gains that the TCM signal has, and one of them is equation (1).
Substituting the following numbers into

From n ″ = 100 / (2 × 1.4 × 1000 × 0.001) = 35.7, the multiple load gain is 23 dB with reference to Reference 4, and the other one is a transmission signal. Since only 1/2 is sent, the increase in multiple load gain due to the reduction in power is 3d.
There is B. Therefore, the total of both is 26 dB.

On the other hand, when the above measure is not performed, n '= 100 / (2 × 3.0 × 1000 × 0.001) = 16.6 It becomes 18 dB. Therefore, the increase in the multiple load gain is 8 dB.
This indicates that the transmission power can be reduced to 1/6.

However, the above is an example of trial calculation, and TCM
Signal multiplicity n = 100, frame length 0.001 ms
It was calculated as ec.

(4) Theoretical explanation that the wireless carrier interval can be narrowed How much the wireless carrier interval can be narrowed will be described using the example already described in (3). If the maximum frequency of the telephone signal is shifted from 3.0 kHz to 2.8 kHz, the frequency component of the temporally compressed delimited signal is also shifted to the low frequency range. The occupied bandwidth of the frequency of the modulated wave that is angle-modulated by using is reduced. If you check how much it decreases, you get 7%. Therefore, the wireless carrier spacing is 7%
It is possible to make the size narrower than in the past. This is a value that cannot be ignored for effective use of frequency.

Next, regarding the effective use of the frequency by deleting a part of the transmission signal, since the maximum frequency of the signal included in the TCM signal is halved, the radio carrier interval is reduced. Can be narrowed to one half of the conventional one.

Furthermore, if the frequency band of the telephone signal is shifted to the low frequency band and the transmission signal is partially deleted, it is possible to further improve the effective frequency utilization. For example, in the above example, the effective frequency utilization is improved by about 2.2 times.

(5) Specific System Configuration Example for Improving Frequency Effective Utilization etc. FIGS. 11, 12 and 13 show system and time slot configuration examples for explaining a specific embodiment of the present invention. 14 to 16 and the time of FIG.
The schematic diagram of the production method which produces a time piece signal using a slot is shown. Since FIG. 11 corresponds to FIG. 2, FIG. 12 corresponds to FIG. 3, and FIG. 13 corresponds to FIG. 4, respectively, the description of FIG. 2, FIG. 3 and FIG. 4 will be omitted, and the newly added function will be mainly described.

FIG. 11 differs from FIG. 2 in that a reception signal selector 171 and a transmission signal selector 172 are inserted.

12 is different from FIG. 3 in that the received signal selection circuit group 71 including the received signal selection circuits 71-1, 71-2, ..., 71-n and the transmission signal selection circuit 72-.
The point is that a transmission signal selection circuit group 72 including 1, 72-2, ..., 72-n is inserted.

The mobile radio 100B shown in FIG. 11 and FIG.
And the reception signal selector 17 included in the radio base station 30B
1, a transmission signal selector 172 and a reception signal selection circuit group 71,
A state of signal processing when the transmission signal selection circuit group 72 and the transmission signal selection circuit group 72 transmit and receive using the time slot shown in FIG. 13 will be described.

FIG. 14 shows how each time slot SD or SU shown in FIG. 13 is created (of which SD1a,
Fig. 3 is a schematic diagram of a method of creating a time piece signal of a certain telephone signal (frequency component 0.3 to 3.0 kHz), when SD1b is used). The horizontal axis is time, and the vertical axis is the frequency component of the signal (however, the shaded area is deleted after band limitation)
Indicates.

The telephone signal output from the telephone unit 101 is first input to the frequency shifter included in the transmission signal selector 172 (FIG. 11). Here, the frequency component of the telephone signal is shifted to the low frequency range. In the following example, the amount to be shifted is from 0.3 to 3.0 kHz and 0.1 to 2.8 kHz.
0.2 kHz to each Hz. As described above, the time piece signal is generated from the telephone signal thus shifted. However, all the frequency components of the signal are divided into two before the time compression for the TCM conversion from the generated time piece signal, and for example, the lower half (0.1 to 0.1) of the frequency components of the signal is first divided.
1.45 kHz, then the upper half (1.45-2.8 kHz)
z) alternate selections. In the time slot SD1a of the frame number 1-a in FIG. 14, the low frequency component L1 (H1 in the shaded portion is not transmitted), and in the time slot SD1b of the frame number 1L-b, the high frequency component H1 (the shaded portion). L1 is not transmitted), the low frequency component L1 is again used in the time slot SD1a of the frame number 2-a, and the high frequency component H1 is again used in the time slot SD1b of the frame number 2-b. The transmission of the low frequency component and the high frequency component is repeated.

If the signal obtained by the above-mentioned signal processing is transmitted as it is, the maximum frequency of the telephone signal does not change even if the multiple load gain due to the reduction of the transmission power increases by 3 dB. It remains the same as before, and there is no increase in multiplicity, as is clear from the equation (1).

Therefore, prior to signal compression for the high frequency component H1, this is converted to a low frequency equal to that of the lower half by a frequency converter (not shown), and then signal compression (conventional) is performed. (Same compression ratio as) and send. That is, in the time slot SD1a of frame number 1-a in FIG.
In the time slot SD1b of the frame number 1-b, the high frequency component (H indicated by the diagonal line of the frame number 1-a)
The low frequency component Lh1 obtained by lowering 1) is again converted into the low frequency component L1 in the time slot SD1a of the frame number 2-a, and the high frequency component (frame number 2-a) in the frame number 2-b. The low-frequency component Lh1 obtained by lowering the H1) indicated by the diagonal line is transmitted, and thereafter, the low-frequency component Lh1 obtained by lowering the low-frequency component and the high-frequency component is repeated for each frame. Become.

By the above signal processing, as is clear from the equation (1), f _h is 1 / 2.14, the multiplicity n is doubled, and the transmission signal power is ½ of the conventional value. Is becoming Therefore, as described above, the increase in the multiple load gain is 8d.
It becomes B. Furthermore, the carrier frequency interval is about 1/2
It has become possible to reduce the effective frequency utilization rate.

In the above description, the frequency component of the telephone signal is converted into each time piece signal (hence the time component after time compression).
However, it is possible to further improve the effective frequency utilization. For example, the frequency component of the telephone signal may be transmitted only 1/3 in each time piece signal. If so, the effective frequency utilization is tripled. It is also possible to change the frequency component to be transmitted to various values such as 2/5 and 2/3 of the original signal.

On the contrary, when it is not necessary to raise the effective frequency utilization so much, half of the frequency components of the telephone channel used in the system transmit all time piece signals, and the other half use time piece signals. Send only 1/2 or 1
The duty may be set to 70% so that all the time piece signals are transmitted for each frame and half the time piece signals are transmitted in the next frame. Then, a line with a large duty may be distinguished from a high-quality telephone line and a line with a low duty may be distinguished from a low-quality telephone line to discriminate usage charges.

A description will be given of an adverse effect on the communication quality after demodulating a modulated wave on the receiving side and a method of reducing this adverse effect as much as possible by creating the time piece signal on the transmitting side. As an example, time slots SD1a and SD1b (in which the telephone signals (L1, H
1) is used), and the communication quality when a signal is transmitted from the transmitting side in the format of FIG. 14 will be described.

FIG. 15B shows an input signal to the reception signal selector 171 when the mobile radio 100B receives a signal from the radio base station 30B (telephone time signal L1, Lh.
1) is shown.

The reception signal selector 171 first performs frequency conversion on the low frequency component time piece signal Lh1 of these signals and includes it in the time piece signal Lh1 of the telephone signal. Then, the restoration of the high frequency component (0.1 to 1.45 kHz) that has been lowered is started. That is, with respect to the time piece signal Lh1 of the low-frequency component shown in FIG. 15B, the signal low-frequency-converted by the frequency converter (not shown) is converted into the original frequency component (1 .45 to 2.8 kHz). As a result, the time piece signal L1 (time slot SD1a) and H1 (time slot SD1b) as shown in FIG.
Are frame numbers 1-a, 2-a, ..., and 1 respectively.
-B, 2-b, ... As shown in the figure, the demodulated call signal shows that the frequency component is sent only with a duty of 50%. That is, in FIG.
Frame numbers 1-a, 2-a, 3-a, ... Shown in (a).
The slot number SD1a of 1 contains a frequency component of 0.1 to 1.45 kHz as a useful signal, and
Only noise is contained in 45 to 2.8 kHz. On the other hand, the slot number SD1b of the frame numbers 1-b, 2-b, 3-b, ... Includes only 1.45 to 2.8 kHz as a useful signal,
Only noise is included at 1.45 kHz. If it is left as it is, it will have a bad influence on the call quality and will be difficult to use.
On the other hand, FIG. 16B shows an example of a measure (comprising a signal shaping circuit (not shown)) for reducing this adverse effect. In the figure, as the signal of the time slot number SD1b corresponding to the frame numbers 1-b, 2-b, 3-b, ...
The signal of time slot number SD1a of -a, ... Is duplicated and added as a dummy signal L1d. Further, as the signal of the slot number SD1a corresponding to the frame numbers 1-a, 2-a, 3-a, ..., The frame number 1-b, 2-b, 3-b, ... The signal of the slot number SD1b corresponding to the above is duplicated and added as the dummy signal H1d. By such measures, the adverse effect on the call quality is considerably reduced.

Now, what kind of time length is preferable for the time piece signal of the TCM signal will be explained. Obviously, it is better that the time length is shorter (for example, 1 msec rather than 10 msec). However, if it is too short, the efficiency in signal processing deteriorates, so there is a fixed limit (about 1 msec).

Now, the telephone signal restored by the above circuit is not the original signal accurately because its frequency component is shifted to the reduction. In order to restore the original signal, it is necessary to pass the frequency shifter included in the reception signal selector 171. That is, depending on the frequency shifter, 0.1 to 2.8 kHz
Telephone signal of each is shifted to high frequency by 0.2kHz,
A telephone signal having a component of 0.3 to 3.0 kHz which is the original frequency of the transmission signal is reproduced.

With the above measures, it is possible to increase the effective frequency utilization rate without causing a significant adverse effect on the call quality.

The generation of the time piece signal (transmission side) described with reference to FIGS. 14 to 16 is performed by the transmission signal selector 172 (FIG. 11).
And the transmission signal selection circuit group 72 (FIG. 12) performs restoration of the original signal on the reception side that receives the time piece signal. The reception signal selector 171 (FIG. 11) and the reception signal selection circuit group 71
(FIG. 12).

FIG. 17 shows a concrete circuit configuration diagram of an embodiment of the transmission signal selector 172 and the reception signal selector 171 used for improving the frequency effective utilization rate.

The transmission signal selector 17 shown in FIG. 17 (a)
2 includes a frequency shifter FS21, a switch SW21,
SW22, low-pass filter LP21, high-pass filter H
P21 and frequency converter FC21 are included. Here, for the radio base station 30B, from the mobile radio 100B to the time slots SU1a and SU1b, the frequency components of the telephone signal are shifted to the lower side by 0.2 kHz for each frame, and only the low or high band of the signal is shifted. A time piece signal is created to transmit half the frequency components.

When the frequency shifter FS21 shifts the transmission signal from the telephone unit 101 to the lower side by 0.2 kHz, the control signal from the control unit 140 causes the switch SW21 which performs a switching operation to switch to the low frequency range. It is applied to the pass filter LP21 or the high pass filter HP21. The output of the high-pass filter HP21 is the frequency converter FC.
At 21, the frequency is converted to the low frequency range. Low pass filter LP2
1 and the output of the frequency converter FC21 are controlled by the control unit 140.
Switch SW22 that performs switching operation according to the control signal from
And is applied to the speed conversion circuit 131.

Mobile radio 100B to radio base station 30B
The signal to be sent to is the time slot SU1a of the 1-a frame in FIG. 13B (corresponding to SD1a in FIG. 16B).
, The transmission signal after frequency shift (0.2 kHz) to the lower side from the telephone unit 101 is used for low range (0.1-1.4).
5 kHz), switches SW21, S
W22 is connected to the terminal a side to obtain the time piece signal L1. As a result, only the useful low-frequency signal (0.1 to 1.45 kHz) is transmitted from the telephone unit 101 to the speed conversion circuit 131.
Will be sent to. Then, through the wireless transmission circuit 132, the frame number 1-addressed to the wireless base station 30B from the antenna
a time slot SU1a is transmitted.

In the next 1-b frame, the signal sent from the mobile radio 100B to the radio base station 30B is as shown in FIG.
(B) 1-b frame time slot SU1b
By using (corresponding to SD1b in FIG. 16B), the transmission signal after the frequency shift (0.2 kHz) from the telephone unit 101 to the lower side by the frequency shifter FS21 is used as a high frequency component (1.45 to 2). Frequency converter FC21 to convert the frequency component to the frequency range of the low frequency signal (0.1 to 1.45 kHz),
The switches SW21 and SW22 are connected to the terminal b side to obtain the time piece signal Lh1.

In the next frame, the mobile radio 1 again
The signal sent from 00B to the wireless base station 30B is as shown in FIG.
(B) 2-a frame time slot SU1a
By using (corresponding to SD1a in FIG. 16 (b)), a useful low-frequency signal (0.1) is transmitted from the telephone unit 101 via the frequency shifter FS21 in the same manner as in the 1-a frame.
˜1.45 kHz) will be sent as the time piece signal L1.

In the next 2-b frame, as in the case of the 1-b frame, the time slot SU1b of the 2-b frame of FIG. 13 (b) (SD1b of FIG. 16 (b)).
Corresponding to a useful high frequency signal (1.45-2.2) that has passed through the frequency shifter FS21 from the telephone unit 101.
Only the frequency component (8 kHz) is converted by the frequency converter FC21 into the frequency range (0.1 to 1.45 kHz) of the low frequency signal, and is sent as the time piece signal Lh1.

FIG. 17 (b) shows a reception signal selector 171 for improving the effective utilization of frequency, and the switch S
W11, SW12, a low pass filter LP11, a high pass filter HP11, a frequency converter FC11 and a frequency shifter FS11 are included. Here, the wireless base station 3
A signal from 0B to the mobile wireless device 100B is processed. For example, by using the time slots SD1a and SD1b (FIG. 13) assigned to the mobile wireless device 100B, the frequency components are transmitted to the low frequency component range L1 and the low frequency component range L1 of the incoming telephone signal. The time piece signal Lh1 whose components have been converted is taken out.

When the mobile radio 100B receives the time slot SD1a (FIG. 13) of the 1-a frame,
7 (b), the switches SW11 and SW12 of the reception signal selector 171 are connected to the terminal a side by the control signal from the control unit 140, and the speed restoration circuit 138.
Of the input signal from the low frequency component (0.1
˜1.45 kHz), that is, only the signal of the time piece signal L1 (FIG. 15 (a)) is sent to the telephone section 101 through the low-pass filter LP11 and the frequency shifter FS11. Here, high frequency components (1.45-2.8k)
Hz, H1 in the shaded area in FIG. 15 (a) is undesired noise, and is suppressed by the low-pass filter LP11.

Next, the time slot S of the 1-b frame
When the mobile wireless device 100B receives D1b (FIG. 13),
As shown in FIG. 15 (a), the time slot SD1b includes a high-frequency time piece signal Lh1 for the low frequency band addressed to the mobile wireless device 100B.
In (b), by the control signal from the control unit 140,
The switches SW11 and SW12 are connected to the terminal b side, and the frequency converter FC11 is used to restore the original high frequency component (1.4
5 to 2.8 kHz), high-pass filter HP11
According to the signal (1.
Only 45 to 2.8 kHz is passed, and low-frequency signals that are noise components are suppressed. This signal is a frequency shifter FS1
1, the signal component is 1.45 to 2.8 kHz to 1.6
The signal frequency is shifted to 5 to 3.0 kHz and becomes the signal frequency of the original telephone signal.

The next 2-a frame causes the radio base station 30 to
Time slot SD1 from B to mobile radio 100B
When a is sent (FIG. 13), the switches SW11 and SW12 are connected to the terminal a side by the control signal from the control unit 140, and the same operation as in the case of the 1-a frame is performed, and the low range After extracting only the frequency component (L1) without noise and passing it through the frequency shifter FS11, the telephone unit 1
Send to 01.

Further, when the time slot SD1b is sent from the radio base station 30B to the mobile radio 100B in the next 2-b frame (FIG. 13), the time slot SD1b is transmitted in the same manner as in the case of the 1-b frame. Signal Lh1 (Fig. 15
Only the high-frequency signal (1.45-2.8 kHz) subjected to the low-frequency processing included in (a)) is taken out without noise and passed through the frequency shifter FS11, and then the telephone unit 10
Send to 1.

The above is the description of the operation performed by the reception signal selector 171 and the transmission signal selector 172 of the mobile radio device 100B for one telephone signal.

Regarding the radio base station 30B which communicates with the mobile radio device 100B in the opposite direction, the transmission signal selection which is a circuit which performs the same operation as the transmission signal selector 172 and the reception signal selector 171 described in the mobile radio device 100B. Circuit 72-1
The operation of the present invention can be executed by providing the transmission signal selection circuit group 72 including 72-n and the reception signal selection circuit group 71 including reception signal selection circuits 71-1 to 71-n.

[0124]

As is apparent from the above description, the multiple load gain of the TCM signal is increased by converting the frequency component of the telephone signal to the low frequency band and then converting it to TCM. Is used to increase the modulation deviation of the angle modulation (to increase the modulation rate of the amplitude modulation), the S / N can be improved, which can also be used to reduce the transmission power.
In addition to enabling power saving, angle modulation using this reduces the occupied bandwidth of the frequency band of the modulated wave, making it possible to narrow the wireless carrier spacing and effective frequency utilization. Therefore, the effect of the present invention is extremely large.

[Brief description of drawings]

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

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

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

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

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

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

FIG. 7 is a 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 circuit configuration diagram of a specific example of a mobile wireless device used in the system of the present invention.

FIG. 12 is a circuit configuration diagram of a specific example of a radio base station used in the system of the present invention.

FIG. 13 is a time slot structure diagram for explaining a specific example of a time slot used in the system of the present invention.

FIG. 14 is a time slot contents diagram showing the contents of the embodiment of the time slot shown in FIG.

FIG. 15 is a time slot content diagram showing the contents of another embodiment of the time slot shown in FIG.

FIG. 16 is a time slot contents diagram showing the contents of still another embodiment of the time slot shown in FIG. 13.

FIG. 17 is a circuit diagram of an embodiment of a transmission signal selector and a reception signal selector for creating and restoring the time slots shown in FIGS. 14 to 16;

[Explanation of symbols]

 10 telephone network 20 barrier exchange 22-1 to 22-2n communication signal 30 radio base station 31 signal processing unit 32 radio transmission circuit 35 radio reception circuit 38 signal speed restoration circuit group 38-1 to 38-n signal speed restoration circuit 39 signal Selection circuit group 39-1 to 39-n Signal selection circuit group 40 Control unit 41 Clock generator 42 Timing generation circuit 51 Signal speed conversion circuit group 51-1 to 51-n Signal speed conversion circuit 52 Signal allocation circuit group 52-1 -52-n signal allocation circuit 71 reception signal selection circuit group 71-1 to 71-n reception signal selection circuit 72 transmission signal selection circuit group 72-1 to 72-n transmission signal selection circuit 91 digital encoding circuit 92 multiplex conversion circuit 100, 100-1 to 100-n Mobile radio 101 Telephone section 120 Reference crystal oscillator 121-1 and 121-2 Synthesizer The 122-1 and 122-2 switches 123 transmission / reception gating controller 131 speed conversion circuit 132 wireless transmission circuit 133 transmission mixer 134 transmission unit 135 wireless reception circuit 136 reception mixer 137 reception unit 138 speed restoration circuit 141 clock regenerator 171 reception signal selection 172 Transmission signal selector FC11, FC21 Frequency converter FS11, FS21 Frequency shifter H1, L1 Time piece signal HP1, HP2 High-pass filter LP1, LP2 Low-pass filter SW11-SW13, SW21-SW23 Switch

Claims (1)

[Claims] 1. A radio base means (30) each of which covers a plurality of zones to form a service area, and a frame structure for moving across the plurality of zones and communicating with the radio base means. Mobile communication using barrier exchange means (20) for exchanging communication with each mobile radio means (100) using radio channels carrying time-compressed delimited signals in time slots In the time division communication method, the frequency band of the signal of the first communication, which is one of the communication, is shifted to a low frequency, and the low frequency signal is divided into a low frequency signal and a high frequency signal to divide the low frequency signal. A low-frequency time-slice signal (L1), frequency-converting the wide-area signal to generate a low-frequency-reduction high-frequency time-slice signal (Lh1) in the same frequency range as the frequency range of the low-frequency signal, and the time slot Alternating with The time division communication method in a mobile communication which is adapted put the low-frequency time piece signal low Ikika high frequency time piece signal.