JPH05183491A - Time division c0mmunicati0n method for mobile communication - Google Patents

Abstract

PURPOSE:To provide the large multiple load gain by taking a telephone signal taken out by the time change of the amplitude as the time-compressed and separated one. CONSTITUTION:The control of a radio reception circuit 35 of a radio base station 30 or the output of a speech signal is inputted to a selection circuit group 39 including signal selection circuits 39-1 to 39-n selecting signals by each time slot. The speech signal is separated corresponding to each speech channel in the circuit group 39. The output recovers the signal speed of a time difference telephone signal and the telephone signal by a signal speed recovery circuit 38 provided for each channel. After inputted to a signal processing section 31 for the 4 to 2-line exchange, it is sent to a gate exchange 20 as communications signals 22-1 to 22-n. The signal power of the time difference telephone signal becomes remarkably reduced and the large multiple load gain can be obtained, the radio base station 30 and the mobile radio device can decide the transmission level based on the gain, enabling to reduce the transmission power and to make an effective use of the frequency.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a system in which a signal having a band characteristic such as that of a telephone is time-divided / time-compressed and then modulated, and the redundancy of the transmission signal is reduced. The present invention relates to an effective use method of frequency and an effective use method of frequency. 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 R
CS89-11 July 1989

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

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

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

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

That is, in Reference 1, a transmission signal (baseband signal) is divided into predetermined time interval units and stored in a storage circuit, and when this is read, it is n times faster than the storage speed in the storage circuit. Built in mobile radios and radio base stations to read at a predetermined time slot, angle-modulate or amplitude-modulate a carrier wave with the signal accommodated in this time slot, and to transmit and receive intermittently in time. , A switch for a radio receiving circuit having a receiving mixer that communicates with each other, a radio transmitting circuit having a transmitting mixer, a synthesizer applied to the receiving mixer of the radio receiving circuit, and a synthesizer applying to the transmitting mixer of the radio transmitting circuit A circuit is provided, and the output of the synthesizer applied to each is interrupted, and this interrupted state is transmitted and received. For the wireless base station that communicates with each other 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.

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

FIGS. 13A to 13E show waveforms of vowel sounds a, d, a, o, and u of a voice. The first formant of vowel a in FIG.
z, the second formant is at 2400-3000 Hz. The first formant of vowel D in (b) is 350-55.
0 Hz, the second formant is 1500-2000 Hz,
The third formant is at 2500-3000 Hz, and similarly in the case of the vowel a in (c), 600-800 Hz,
1000-1400Hz, 2700-3100Hz,
In the case of the vowel sound (d), 420-500 Hz, 760-
1000 Hz, 1300 to 2000 Hz, 300 to 480 Hz, 1000 to 1400 H in the case of vowel U of (e)
z, 2000-3000 Hz.

The frequency component that characterizes such a vowel is called a formant. On the other hand, the consonant appears in a transient manner only for a short time, its frequency component is relatively high, and its energy is extremely small. Figure 14 is "CHO"
In the pronunciation waveform of (cho), the part where the amplitude is large and conspicuous is CH
This is the part of the vowel O that follows, and the essential consonant is the fine waveform part that appears at the beginning.

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

Next, the relationship between the energy of voice and the amount of information will be described with reference to FIG. Even if the peak appearing in the waveform of the voice is compressed and removed, the amount of transmitted information does not change much. On the other hand, if the vicinity of 0 of the voice waveform is removed, the amount of information carried will drastically decrease even if a large amplitude area is left as it is. FIG. 15 shows the results of this experiment, in which the horizontal axis shows the amount of removal of the peak or zero portion of the speech waveform, and the vertical axis shows the decrease in word intelligibility caused by such removal.

FIG. 16 clearly shows the removal conditions when the vicinity of 0 and the peak of the experimental data of FIG. 15 are removed. Here, the peak removal amount = 20 log (p ₁ / p ₀ ) (dB) 0 vicinity removal amount = 20 log (p ₂ / p ₀ ) (dB).

[0018]

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

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

[0020]

[Means for Solving the Problems] Telephone signals are transmitted to TCM-FM.
At the time of transmission, the telephone signal was compared with the previous frame signal for each frame, and the telephone signal (hereinafter referred to as the time difference telephone signal) extracted by the temporal change in amplitude was temporally compressed and separated. By using a signal, it is possible to obtain a larger multiple load gain than the value that has been clarified so far.

[0021]

13 and 14 show that when the majority of the duration of the telephone signal is divided into short time intervals (for example, 10 ms),
It shows that the same signal is repeated repeatedly. This indicates that when a telephone signal is divided into time signals and a time difference telephone signal that is a time change of the telephone signal is created, the signal often has an extremely small component. When such a time-difference telephone signal is created, there are many cases in which the signal has very few components, so that it is possible to obtain a larger multiple load gain than ever before. That is, in the TCM signal, in addition to the multiple load gain that has been clarified up to now, it is possible to obtain a new gain that is the load gain of the time difference telephone signal. Can be obtained, and while keeping interference and interference within the allowable value,
By increasing the modulation degree of FM (PM) modulation, the transmission output can be gradually reduced. Therefore, 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.

[0022]

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, 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 an analog signal) of the communication signal, which is a compressed and delimited time difference telephone signal (detailed later) in the received signal, and outputs a continuous signal. Is input to the telephone unit 101 and the control unit 140.

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

The output of the modulator included in the transmission unit 134 is converted into a predetermined radio frequency in the transmission mixer 133,
The signal is transmitted from the antenna unit and received by the wireless base station 30. In order to 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. An input signal from the gateway exchange 20 is input to a signal speed conversion circuit group 51 including many signal speed conversion circuits 51-1 to 51-n, and is divided at predetermined time intervals to obtain a time difference telephone signal. , Undergo velocity (pitch) conversion. As for the signal transmitted from the wireless base station 30 to the gateway switch 20, the output of the wireless reception 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, The original telephone signal is restored from the time difference telephone signal and 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 restored by the signal speed restoration circuit group 38 including the signal speed restoration circuits 38-1 to 38-n provided for each channel to restore the signal speed (pitch) of the time difference telephone signal and restore the telephone signal. After that, after being input to the signal processing unit 31 and undergoing 4-line to 2-line conversion,
This output is the communication signals 22-1 to 22- to the gateway switch 20.
sent as n.

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

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

The control or voice signal output from the gateway switch 20 via the signal processing section 31 is input to the signal speed conversion circuit group 51, and after speed (pitch) conversion and time difference signal processing are performed, It is applied to a signal allocation circuit 52 which allocates a signal for each time slot.

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, as shown in the figure, a synchronizing signal and a call signal which is a time difference telephone signal or / and a control signal are accommodated. 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. Thus, as shown in FIG. 4A, in the wireless transmission circuit 32, the time slots SD1 to S
A signal forming one frame with Dn is added to the modulation circuit. The time-multiplexed multiplexed signal to be transmitted is
In the wireless transmission circuit 32, after being angle-modulated, it is 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.

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

Although the above is the case of the analog signal, when the digital data signal is used as the control signal, the voice signal which is the time difference telephone signal is also digitally encoded, and both are time-division multiplexed and transmitted. This is also possible, and the 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 multiplex load gain, which will be described later, usually does not 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. Further, when the contents of each time slot SU1, SU2, ..., SUn are shown in detail, as shown in the lower left of FIG. 4 (b), it is composed of a call signal which is a time difference telephone 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. Furthermore, the waveform of the radio carrier of the uplink radio signal in the time slot is schematically shown in FIG. 7 (c). Similarly, the transmission waveform from the wireless base station 30 to each mobile wireless device 100 is shown in FIG.
As shown in (d).

The control signal of the input signals arriving at the radio base station 30 is immediately added from the radio reception circuit 35 to the control unit 40. However, depending on the size of the speed conversion rate, it is 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 in the present invention will be described by using the required transmission band and the relationship between the transmission band and the adjacent radio channel.

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

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

Original signal, eg voice signal (0.3 kHz-
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 voice signal which is the time difference telephone signal is converted 15 times as described above, the frequency distribution of the signal is expanded to 4.5 kHz to 45 kHz as shown in FIG. 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 voice signal which is the time difference telephone signal. Of these signals, control signal (0.2 to 4.0 kHz) and call 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 added to the angle modulation section included in the radio transmission circuit 32 together with the control signal, a required transmission band of at least f _C ± 45 kHz is required. However, f _C is a radio carrier frequency. If there are a plurality of wireless channels given to the system, the speedup of signals by the signal speed conversion circuit group 51 is limited to a certain value due to the limitation of these frequency intervals. 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, the mobile wireless device 100 is connected to the wireless base station 3
The control signal input to 0 is input to the wireless reception circuit 35, part of its output is input to the control unit 40, and the other is sent to the signal speed restoration circuit group 38 via the signal selection circuit 39. . The latter control signal undergoes speed conversion (conversion to a low speed signal) completely opposite to that at the time of transmission, and then the general telephone network 10
The signal speed is the same as that used in the above, and 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 telephone 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 it may be 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 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.

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 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 from the gateway switch 20 (initially a 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 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 Device 100 The mobile radio device 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 the fact that signal transmission is executed in a good state using this system and that it does not adversely affect other radio channels in the system is theoretically explained in Reference 2, and is therefore omitted. However, the increase in the multiple load gain of the time difference telephone signal will be described below.

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

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

Next, the characteristics of the case where the TCM signal is created from the analog phone signal based on the time difference phone signal will be described. FIG. 11A is a diagram of FIG.
The signal "a" shown in FIG. 11A is shown, and FIG. 11B shows an example of the time difference telephone signal generated from the signal by using the temporally adjacent time piece signals. That is, FIG.
1 (a) vowel "i" (total time is about 220 ms) 10
The signal is cut every ms to make a time piece signal, and from these, the same figure (b)
The time difference telephone signals are created and arranged in a line.
However, it is assumed that the pulse noise generated at the time of shifting from one time piece signal to the next time piece signal is removed. Figure 1
3, the following can be seen from FIGS. 14 and 11.

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

2) Since the time length of the time piece signal is about 1 to 30 ms, it is a time length suitable for catching a minute change of the audio signal. As is clear from FIG. 13 and FIG. 14, the signal waveforms of the temporally adjacent time piece signals are almost the same except for a part.

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

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

Next, the TCM created by the time difference telephone signal
Find the multiple load gain of the signal. To be precise, it is necessary to create a time difference telephone signal similar to that shown in FIG. 11B for many voice signals based on FIGS. 13 and 14 and obtain the distribution thereof or to perform an experiment. , Omitted here, and the reduction of the average power of the time difference TCM signal is 9
Reduce by 0% (actually larger). At this time, the multiple load gain is easily increased 10 times (10 dB).

Next, a method of creating the time difference telephone signal described above will be described with reference to FIG. FIG. 12 shows the internal structures of the speed restoration circuit 138, the telephone unit 101, and the speed conversion circuit 131 in the structure of the mobile wireless device 100 shown in FIG.

In FIG. 12, the radio receiving circuit 1 is shown from the right side.
The compressed time difference telephone signal (difference signal) from 35 is input. This input signal is timed by switch 165.
It is input and stored in the telephone signal storage circuit 161-1 or 161-2 for each slot (one for each TCM frame). The terminals a and b of the switch 165 are
The timing of the switching of is performed by a signal from the timing generator 142. The signal stored here is then read out and restored to the original telephone signal rate by the time expansion circuit 162-1 or 162-2. Then, the restored telephone signal is still in the form of a time difference telephone signal, and the telephone signal is generated by switching the terminals a and b of the switch 166-1 or 166-2 (this timing also depends on the signal from the timing generator 142). It is input to the reproduction circuit 163-1 or 163-2. Here, the time difference telephone signal (difference signal) is added to the signal in the time slot of the frame immediately before that, and the original telephone signal for one frame is reproduced. Then, by switching the terminals a and b of the switch 167 (this timing also depends on the signal from the timing generator 142), the output of the telephone signal reproducing circuit 163-1 or 163-2 is taken out alternately, and the telephone unit 10
1 to the receiving circuit 106.

The internal structure of the telephone section 101 is shown on the left side of FIG. 12, and the control section 140 and the telephone control circuit 105 are shown.
Control signals are exchanged between the two. Also, the receiving circuit 1
06, and the transmission circuit 107 is a clock recovery circuit 141
It is working by getting the signal from.

The lower part of FIG. 12 shows the internal structure of the speed conversion circuit 131. The telephone signal output from the transmission circuit 107 of the telephone section 101 is switched by the switch 175 to the telephone signal storage circuit for each frame of the telephone signal. 171-1 and 171-2 are input and stored respectively. The timing of switching the terminals a and b of the switch 175 is performed by a signal from the timing generator 142. The signal stored here is read out and the difference signal generating circuit 172-1 or 172-2 is generated by switching the terminals a and b of the switch 176-1 or 176-2 (this timing also depends on the signal from the timing generator 142). Where the telephone signal is converted into a time difference telephone signal by subtracting (taking a difference) from the telephone signal of the immediately preceding frame. The converted time difference telephone signal is then transmitted to the time compression circuit 1
73-1 or 173-2. Then, by switching the terminals a and b of the switch 177 (this timing also depends on the signal from the timing generator 142), the TCM
The signal is sent to the wireless transmission circuit 132 for each time slot (one is given for each TCM frame unit).

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

Next, the operation of the radio base station 30 will be described. Among the configurations of the radio base station 30 shown in FIG. 3, the internal configurations of the signal speed restoration circuit group 38 and the signal speed conversion circuit group 51 are different except that signals are transmitted and received at the same time as a large number of mobile wireless devices. For example, it has substantially the same functions as the speed restoration circuit 138 and the speed conversion circuit 131 of the mobile wireless device 100.

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

[0094]

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

[Brief description of drawings]

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

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

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

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

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

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

FIG. 7 is a 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 waveform diagram showing a time difference signal waveform (b) used in the present invention, which is obtained from the signal waveform (a) of FIG.

FIG. 12 is a detailed circuit configuration diagram of a speed restoration circuit, a telephone unit, and a speed conversion circuit which are the constituent elements of FIG.

FIG. 13 is a waveform diagram of a vowel.

FIG. 14 is a waveform diagram of consonant + vowel (cho).

FIG. 15 is a characteristic diagram showing information transmission amount characteristics when peaks are removed from a telephone signal and when the vicinity of 0 is removed.

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

[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 Transmission unit 135 Radio reception circuit 136 Reception mixer 137 Reception unit 138 Speed restoration circuit 141 Clock regenerator 161-1, 161-2 Telephone signal storage circuit 162-1, 162-2 Time extension circuit 163-1, 163-2 Telephone signal Reproduction circuit 165, 166-1, 166-2, 167 Switch 171-1, 171-2 Telephone signal storage circuit 172-1, 172-2 Difference signal creation circuit 173-1, 173-2 Time compression circuit 175, 176- 1,176-2,177 switch

Claims (1)

[Claims] 1. A service which covers a plurality of zones, respectively.
Each wireless base means (30) forming the service area,
Note that the wireless base means can be moved across multiple zones.
Time to framed time slots to communicate
A wireless channel carrying a dynamically compressed delimited signal
Exchange communication with each mobile radio means (100)
At the time of mobile communication using the gateway exchange means (20) for
In the inter-division communication method, when the temporally compressed delimited signal is a telephone signal
Is the difference signal that is the change over time for each frame.
By obtaining a temporally compressed delimited signal,
And the radio base means based on the obtained multiple load gain.
A radio signal used for communication with the mobile radio means.
A mobile communication time division communication method for determining a bell.