JPH05145484A - Time division communication method in mobile body communication - Google Patents

Abstract

PURPOSE:To reduce a repetitive zone number by using a same radio carrier so as to apply composite modulation to a telephone signal thereby sending/ receiving the resulting signal in the mobile body communication in which a time compressed signal is superimposed on a time slot of frame configuration. CONSTITUTION:A telephone signal is frequency-modulated by using one time slot of a radio channel allocated between a mobile radio equipment 100 and a radio base station 30 and the modulated signal is sent/received while the signal is amplitude-modulated again by using the same telephone signal. Since the carrier is frequency-modulated and then amplitude-modulated by using the same telephone signal, a large multiplex load gain is obtained and required transmission power is reduced, the interference to an adjacent radio zone is prevented in advance, the repetitive zone number is reduced to utilize the frequency effectively.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a radio base station for time division communication of a radio communication channel and a mobile radio in a mobile communication to which a small zone system is applied. More specifically,
A certain one of many radio channels provided to the system is provided, and one of many mobile radios in a service area is provided with the radio channel by an opposite radio base station and a telephone signal. When another mobile wireless device wants to communicate using the same wireless channel while setting to and using the communication signal, the mobile wireless device and the wireless base station that are already communicating It is possible to set up independent wireless lines using the same wireless channel between other mobile wireless devices and the wireless base station while maintaining high effective utilization of frequency without adversely affecting communication of , A time division communication system of the same radio channel.

[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 systems-Study on multipath propagation characteristics of time division time compression multiple FM system-"
IEICE Technical Report RCS89-47 January 1990

Reference 3. Ito "Elucidation of multiple load gain of time division time compression multiplex telephone signal and its application to FM mobile communication" IEICE Technical Report RCS89-65 Mar. 1990.

Reference 4. Fujimoto, Ito "On Time Diversity Effect Using Complex Modulation Waves" The Institute of Electronics, Information and Communication Engineers 19
1991 Autumn Meeting B-218 September 1991

Reference 5. Maruyama, Ito "Verification of Whether Time-Division Time-Compression Multiplexed (TCM) Telephone Signals Have Multiple Load Gains" IEICE Technical Report CS91-84 October 1991

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 Reference 2, the effect of multipath fading that a TCM signal receives during transmission in space is examined, and guard time is provided between time slots as a measure for removing or reducing this effect. Suggest to set.

Further, in Reference 3, the multiple load gain, which has been known to exist in the conventional FDM (frequency division multiplexing) signal, is
The time division time compression multiplex (TCM) method has been clarified to have similar multiple load gain to the FDM signal, and its quantification and system operation examples have been described. 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.

Further, in Reference 4, the occupied frequency bandwidth of a signal when amplitude and angle modulation of one carrier is performed by one signal (composite modulation) is adjusted by adjusting the modulation depth. Is the same as the occupied frequency bandwidth when only angle modulation is performed with one signal.
Furthermore, as an application example of this, time division time compression multiplexing (T
It is explained that the time diversity effect can be obtained by using the CM) telephone signal as the modulation signal and performing the above-mentioned composite modulation.

Further, in Document 5, it is verified by a simulation experiment that the TCM telephone signal described in Document 3 has a multiple load gain. However, the formula giving the quantitative value of the multiple load gain of the TCM telephone signal described in Reference 3 is slightly modified.

[0013]

However, by applying the small zone method, the opposing radio base station and mobile radio set a radio line to divide the same signal into two, and one carrier wave is angle-modulated. By performing complex modulation such as amplitude modulation and amplitude modulation, the diversity effect can be obtained by using this complex modulation to improve the transmission quality of radio signals, and different locations that use the same radio channel can be used relatively closer to each other than before. However, no technique is disclosed in any document that enables the construction of a system with high effective utilization of frequencies.

In order to improve the quality of the transmitted signal, when the opposing radio base station and a large number of mobile radios set up a radio line and communicate by using, for example, a TCM-converted telephone signal, For example, if transmission diversity (assuming that the number of multiplexing is 2) is performed by the conventional method, there is a disadvantage in effective frequency utilization as follows. That is, with frequency diversity, the frequency used is doubled. With time diversity (assuming that the number of multiplexing is 2), the frequency used is the same as before, but the time required for transmission is doubled, which eventually reduces the effective frequency utilization rate by half. It was left.

The current demand for radio wave use is tight, and it is generally necessary in a wireless system to increase the effective utilization of frequencies. The effective utilization of frequencies in a radio system using a TCM telephone signal is considerably higher than that of other radio systems as seen in Documents 1 to 5, but further improvement is required. The present invention meets this need.

[0016]

In order to solve such a problem, in the modulation method according to the present invention, the same carrier is
By using a complex modulation in which a CM-converted telephone signal is angle-modulated and at the same time an TCM-converted same telephone signal is amplitude-modulated, a diversity effect is obtained and at the same time frequency effective utilization is attempted.

In order to realize this, when a radio base station and a mobile radio device opposite to each other use a TCM telephone signal to establish a wireless line and perform communication, the TCM telephone signal is divided into two and one When performing angle modulation and amplitude modulation on the carrier wave simultaneously (composite modulation), the modulation of the angle modulation of the radio signal used for communication between the radio base station and the mobile radio is based on the multiple load gain of the TCM signal. The shift level or the modulation depth of the amplitude modulation is determined, and this modulation signal is further determined by using the radio signal based on the multiple load gain. Depth is compounded to improve the transmission quality of radio signals, and the distance between distant areas where the same conventional radio channel can be used can be made relatively close by the present invention. Only by available and to enhance the effective use of the frequency.

Depending on the type of signal, if the spread of the sidebands of the modulated signal may be wider than that of the single modulation of only the angle modulation or the amplitude modulation, a bandpass filter is provided on the output side of the modulated signal, This makes it possible to limit the spread of the sidebands to a certain spread. Therefore, the spread of the side-pair signals included in the radio signal is substantially the same as that of the sidebands obtained by angle-modulating or amplitude-modulating with a single signal. It is possible to suppress the spread of waves, prevent interference with adjacent wireless channels, and enable efficient use of frequencies.

When a radio base station and a large number of mobile radio devices (n units) facing each other establish radio lines and communicate with each other, a TCM signal transmitted from the radio base station is created as follows. .. That is, after creating a TCM signal from n telephone signals coming from the telephone network to the wireless base station,
This TCM signal is divided into two to create two sets of TCM-converted telephone signals. Angle modulation and amplitude modulation are performed on the same carrier wave using each of these. This composite modulated wave is transmitted to many mobile radio devices. On the other hand, in many mobile radio units facing each other,
The signal is received in the slot and demodulated by a process reverse to that of the time of modulating the composite modulation signal. Further, regarding the composite modulated signal transmitted from the mobile radio device to the radio base station, the telephone signal is subjected to the same time compression as that performed in the radio base station, and is then divided into two minutes. As described above, the same kind of angle modulation and amplitude modulation as that performed in the radio base station is performed in the time slot allocated to itself for the same carrier wave, and then the signal is transmitted to the radio base station. The system configuration will be described.

A plurality of radio base stations having radio transceivers, a radio reception circuit having a reception mixer for communicating while moving within a service area covered by the plurality of radio base stations, and a radio transmission having a transmission mixer. Circuit and switching receiving means including a synthesizer capable of switching and receiving only the signal of the timing given to itself to the receiving mixer of the wireless receiving circuit, and switching only at the timing given to itself to the transmitting mixer of the wireless transmitting circuit In a mobile radio device including a switching transmission means including a synthesizer capable of transmitting, a transmission signal (composite signal of telephone, fax, etc.) is divided into predetermined time interval units and stored in a storage circuit, and then read. At the time of output, the data is read at a predetermined time slot at a speed n times faster than the speed stored in the memory circuit. Lim slot signals contained by (hereinafter referred to as TCM signal.) Angle modulation or amplitude modulation of the same carrier by TCM of telephone signals,
The obtained signal is further amplitude-modulated or angle-modulated by the same TCM-converted telephone signal, and is incorporated in the mobile radio device and the radio base station for intermittently transmitting and receiving in time. A radio receiving circuit having a receiving mixer, a radio transmitting circuit having a transmitting mixer, a synthesizer applied to the receiving mixer of the radio receiving circuit, and a switch circuit for the synthesizer applying to the transmitting mixer of the radio transmitting circuit, and a synthesizer applying each of them. The output is intermittently synchronized, and the intermittent state is synchronized with both transmission and reception, and the mobile wireless device communicating oppositely also uses the same intermittent transmission / reception method as that of the wireless base station, and the receiving side has the predetermined value. In order to extract only the signal accommodated in the time slot, the radio receiving circuit is opened and closed to receive the signal. The signal obtained by demodulation by the process is stored in a memory circuit, and when it is read out, it is read at a low speed of 1 / n of the speed stored in this memory circuit. In the radio base station, a predetermined time slot is used. By providing a communication path control means for setting a communication path with a predetermined mobile wireless device, it is possible to reproduce a baseband signal which is an original signal transmitted in a wireless base station and a mobile wireless device, and a general telephone A system including a gateway switch for connecting the network and the radio base station was constructed.

[0021]

In order to allow a large number of mobile radios to exist in the radio base station and its service area and to communicate with the radio base station by any number of mobile radios, one radio channel is temporally arranged. It is divided into a plurality of time slot series, and one of these time slot series is selected and communication is performed using this. When one mobile radio device is communicating with a radio base station using a composite signal and another mobile radio device desires to communicate with this radio base station, the mobile radio device that newly wishes to communicate using the composite signal In the wireless channel already in use, an unused one of the time slot sequences is given to the device to enable communication with the wireless base station, so that many communications can be performed. It is possible to execute diversity communication without disturbing each other and without adversely affecting own communication.

Furthermore, while one radio base station and the mobile radio are communicating using one time slot in one channel (one time slot of the old channel), In order to maintain and improve the quality, one time slot in the same or another channel with another radio base station satisfying a certain communication quality (one time slot of a new channel I tried to communicate using a slot. The gateway switch also determines the radio channel used for communication with the mobile radio at the radio base station and its time slot as an interface function for connection with other telephone networks and a control function for the mobile radio communication network. , It has a function to stop and start radio waves.

As a result, even if all the radio channels given to the system are in use, if there is an empty time slot not used for communication in each time-divided time slot of each radio channel, It is also possible to make a call to a mobile wireless device that has newly requested a call, and to continue a call to a mobile wireless device that is moving during a call from an adjacent zone. It has become possible for mobile radios communicating with a station to perform diversity communication with other radio base stations in the vicinity.

The modulation method used therein is such that the same carrier is angle-modulated by a TCM-converted telephone signal and at the same time T
Since the spread of the sideband of the modulated signal is limited to a certain spread by the bandpass filter by using the composite modulation in which the same telephone signal converted into the CM is amplitude-modulated, the spread of the sideband signal of the radio signal is It becomes possible to suppress the spread degree when the angle modulation or the amplitude modulation is substantially performed by a single signal.

Due to the diversity effect due to the use of the composite modulation, the transmission power per wireless channel can be significantly reduced, and the number of repeating zones is greatly reduced in the small zone configuration, so that the frequency utilization rate is dramatically improved. However, power saving has been achieved.

[0026]

DESCRIPTION OF THE PREFERRED EMBODIMENTS In a system to which the present invention is applied, a case where an analog telephone signal is converted into a TCM and used will be described in order to explain its principle.

FIG. 1 shows a system configuration for explaining the concept 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 has an interface with the gateway switch 20, a circuit for converting the speed of signals, a circuit for allocating and selecting time slots, a control unit, etc. for setting and releasing a wireless line. , Mobile radio 100 (100-1 to 100-n)
And a wireless transmission / reception circuit for exchanging wireless signals.
Here, between the gateway switch 20 and the wireless base station 30,
There are transmission lines for transmitting the communication signals 22-1 to 22-n including the communication signals of the communication channels CH1 to CHn and the control signals.

FIG. 2 illustrates the principle of the present invention.
The circuit configuration of the mobile wireless device 100 that communicates with the wireless base station 30 is shown. Received signals such as control signals and call signals received by the antenna unit enter the wireless reception circuit 135 including the reception mixer 136 and the reception unit 137, and the output communication signal is the speed restoration circuit 138 and the control unit 140.
Is input to 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 section 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 (in the case of the present invention, a composite modulator of amplitude and angle, generally an amplitude or angle modulator) included in the transmission section 134 is converted into a predetermined radio frequency in the transmission mixer 133, and the antenna is converted into a predetermined radio frequency. And is received by the wireless base station 30. Mobile radio 1
Using the time slot that is allowed to use from 00,
In order to send a wireless signal to the wireless base station 30, it is necessary that the timing information from the timing generator 142 shown in FIG. 2 be obtained via the control unit 140.

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

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

FIG. 3 shows a radio base station 30 for explaining the principle of the present invention. The n-channel communication signals 22-1 to 22-n with the gateway switch 20 are connected to a signal processing unit 31 that forms an interface on a transmission path.

The communication signals 22-1 to 22-n sent from the gateway switch 20 are input to the signal processing section 31 of the radio base station 30. The signal processing unit 31 is provided with an amplifier for compensating for transmission loss, and also performs so-called 2-wire-4 wire conversion. 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. The output signal from the signal speed restoration circuit group 38 is transmitted to the gateway switch 20 by the signal processing unit 31 using the same transmission path as the input signal. 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. In addition, the signal transmitted from the wireless base station 30 to the gateway switch 20 is the wireless reception circuit 3
The output of No. 5 is input to the signal speed restoration circuit group 38 via the signal selection circuit group 39, speed (pitch) converted, 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 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 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 tape
This is the same as playing back the sound recorded by the recorder at high speed. In practice, for example, CCD (Charge Coupl
ed Device) and BBD (Bucket Brigade Device) can be used, and the 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. "Tape recorder that compresses / expands the time axis of conversation" Nikkei Electronics July 26, 1976 92-1
33).

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. It is applied to the signal allocation circuit group 52 which allocates signals separately.

The signal allocating circuit group 52 is a buffer memory circuit, which stores the high-speed signal for one segment output from the signal speed converting circuit group 51, and outputs it from the timing generating circuit 42 given by the instruction of the control section 40. The signal in the buffer memory is read out with the timing information of 1 and 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 communication signals or control 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 given time slots in a predetermined order. S in FIG. 4 (a)
Dn, 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 time-series multiplexed signal to be transmitted is modulated (composite modulation of amplitude and angle in the case of the present invention, generally amplitude or angle modulation) in the wireless transmission circuit 32, and then transmitted to the space from the antenna section. Sent out.

Regarding the transmission of the control signal between the radio base station 30 and the mobile radio 100 prior to the call in the incoming and outgoing call of the telephone, either in the band of the telephone signal or out of the band is used. It is possible. FIG. 5 shows these frequency relationships. That is, in the figure (a), the out-of-band signal is illustrated, and 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. In the above examples, tone signals are used. However, by increasing the number of tone signals or modulating the tones to form subcarrier signals, it is possible to transmit various types of signals at high speed.

Although the above is the case of the analog signal, when the digital data signal is used as the control signal, it is also possible to digitally encode the voice signal and time-division multiplex both of them for transmission. A circuit configuration in this case is shown in FIG. FIG. 6 shows an example in which the voice signal is digitized by the digital encoding circuit 91, the data signal and the data signal are multiplex-converted by the multiplex conversion circuit 92, and applied to the modulation circuit included in the wireless transmission circuit 32. However, for digital data signals, the analog signal multiple load gain, which will be described later, does not normally exist, so this point must be noted in the system design. Then, if the opposite receiver receives the signal and the demodulation circuit performs the reverse operation to that shown in FIG. 6, the audio signal and the control signal can be separately taken out.

On the other hand, the signal sent from the mobile radio 100 is received by the antenna section of the radio base station 30 and input to the radio receiving circuit 35. FIG. 4B schematically shows this upstream input signal. That is, the time slots SU1, SU2, ..., SUn represent transmission signals addressed to the radio base station 30 from the mobile radios 100-1, 100-2, ..., 100-n. Further, when the contents of each time slot SU1, SU2, ..., SUn are shown in detail,
As shown in the lower left of FIG. 4B, it is composed 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 of FIG. 4B in a time slot is schematically shown, FIG.
It becomes like (c). Similarly, the downlink transmission waveform from the wireless base station 30 to each mobile wireless device 100 in FIG.
As shown in (d).

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

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.

The mode of transmitting the signal space in the present invention will be described below with reference to the required transmission band and the relationship with 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, it is possible to add the signal from the output of the signal allocation circuit group 52 to the wireless transmission circuit 32 after performing the same processing as the call signal depending on the magnitude of the speed conversion rate. Next, also in the mobile wireless device 100, as shown in FIG. 2, of the functions of the wireless base station 30, the circuit configuration is required when the communication channel 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.

Now, FIG. 8 shows a case where the control signal is simultaneously transmitted by 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.

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 operations of the system according to the present invention will be explained in the following order, and the fact that the present invention is highly practical and the frequency is effectively utilized will be explained. (1) Call origination and call termination operations (2) Utilization of diversity gain due to multiple load gain and complex modulation to reduce interference in the same radio channel (3) System configuration for complex signal

(1) Calling and Receiving Operations Calling operations 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 possible by capturing the sync signal in the time slot SDn shown in FIG. 4 (a). In the control unit 140, the synthesizer 121-1
To the switch 1 so as to generate a local oscillation frequency that enables reception of the radio channel CH1.
22-1 is also in a state of being tilted down and fixed to the synthesizer 121-1 side.

Therefore, the telephone 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
With the frequency band shown in FIG. 8, this is transmitted, 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 radio base station 30 includes a synchronization signal and a control signal following the synchronization signal, and the mobile radio 100 receives the frame synchronization signal. Will be possible. Further, the control signal includes control information such as a currently used time slot and an unused time slot (empty time slot display). Depending on the system, the time slot SDi (i = 1,
2, ..., N) may contain only a sync signal and a call signal when they are used by other communication, but even in such a case, an unused time slot usually has a sync signal and a control signal. A signal is included, and by receiving this control signal, it is possible to know which time slot the mobile radio device 100 should use to send the calling signal.

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, and at this time, the following audio multiplexed signals SD1, SD2, ..., SD
It is necessary to search for the presence of n 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, assuming that the uplink signal time slot SUn is an empty slot, this empty time slot is used, and a call control signal is transmitted to extract the required timing from the response signal from the radio base station 30. As a result, a burst control signal can be transmitted.

If there is a call from another mobile radio at the same time, the call signal is not properly transmitted to the radio base station 30 due to a collision of calls, and it is necessary to 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 radio 100 shifts to a state in which it can be received in the instructed time slot SD1 and the time for the uplink radio channel corresponding to the downlink time slot SD1.
The slot SU1 (see FIG. 4B) is selected.
At this time, in the control unit 140 of the mobile wireless device 100,
The transmission / reception gating controller 123 is operated and the switch 122-
The operation of 1 and 122-2 is started (S204). At the same time, a slot switching completion report is sent to the radio base station 30 using the uplink time slot SU1 (S20
5) Wait for dial tone (S2)
06).

The time of the wireless carrier of this upstream wireless signal
The state of the slot SU1 is shown in FIG. 7 (c). In addition to the time slot SU1, the radio base station 30 receives SU as an uplink signal from another mobile radio 100.
3 and SUn are sent in one frame. In the wireless base station 30 that has received the slot switching completion report (S207), the mobile wireless device 100 is addressed to the gateway switch 20.
The calling signal is sent out together with the ID of (S208). On the other hand, the gateway exchange 20 detects the ID of the mobile wireless device 100, turns on a necessary switch in the switch group included in the gateway exchange 20 (S209), and dials
The tone is transmitted to the radio base station 30 (S210, FIG. 1).
0). This dial tone is transferred to the mobile wireless device 100 by the wireless base station 30 (S211), and the mobile wireless device 100 confirms that the communication path has been set (S2).
212).

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

On the other hand, an input signal (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. The state of the time slot SD1 of the downlink radio carrier is shown in FIG. 7 (d).

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.

Next, the operation of receiving a call to the mobile wireless device 100 will be described. The mobile wireless device 100 is in a standby state with the power turned on. In this case, as described in the calling operation 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.

(2) Utilization of diversity gain by multiple load gain and complex modulation for reducing same radio channel interference

It is assumed that the mobile communication system used in the description has a small zone structure as shown in FIG. Next, in order to simplify the explanation of the principle of time slot allocation within one frame to be allocated in each small zone, the explanation will be given in comparison with the number of repeated zones known in the small zone system.

As shown in FIG. 11, it is assumed that the service area is covered with regular hexagons of the same size in the basic zone structure. Each radio base station 30 (not shown) is located at the center of the regular hexagon in FIG. 11, and all of the regular hexagons are serviced by using an omnidirectional antenna.
Areas are not overlapped due to leakage to adjacent zones. The number in the center of the unit hexagon is a zone number, up to n = 7. n = 1, 2, ...,
Infinite plane service area (small zone) using 7.
It is possible to cover all over. However, even if n is smaller or larger than n, it does not need to be 7 as long as it is suitable as the number of repeating zones. Also,
The value of n is determined from system requirements. By the way, the repeated zone number 7 means that the number required for the system as a wireless channel is at least 7. That is, it means that the radio channel used for zone 1 (referred to as CH1) cannot be used in the adjacent zones 2 to 7 from the viewpoint of radio interference, and can be used for the first time in the adjacent zones as shown in FIG. To do.

The zone structure described above is generally called a small zone, and the frequency utilization rate is increased by forming the wireless zone into the small zone structure. The reason why the small zone configuration is adopted is that the same radio frequency can be used by the radio base stations 30 closer to each other, but the small zone configuration also has the following advantages.

I) It is often impossible to use the existing mobile communication band for communication for new purposes due to congestion of communication traffic. In this case, a high frequency band of 1000 MHz or more must be used. .. At this time, there is a drawback that the high frequency output cannot be large due to technical or economical reasons, but the small zone method can cover this. ii) In the so-called large zone method that does not use the small zone method, the number of channels per wireless base station, that is, the number of transceivers becomes enormous, and a plurality of antennas are required, which causes problems in equipment installation. Interference interference such as intermodulation becomes a problem, but this can be mitigated by the small zone method. Hereinafter, the number of repeating zones in the existing small zone system and the number of repeating zones in the system to which the present invention is applied will be described in comparison.

In FIG. 12, the radius of the radio zone is r (k
m), and the distance between stations using the same frequency is d (km), the number of repeated zones N is represented by N = 3 ⁻¹ (d / r) ² . The distance d between stations using the same frequency is
The ratio D / U of a desired wave (electric field intensity D of the interfered station) to an interfering wave (electric field intensity U of the interference station) at point A around the radio zone of the interfered station is determined to be a specified value.

In general, in order to perform satisfactory communication in mobile communication, the ratio of the desired wave D to the interfering wave U is set to 24 dB in consideration of the influence of Rayleigh fading (Reference 6. Kamada et al. "Automobile radio system" Nippon Telegraph and Telephone Public Corporation, Research Institute of Communications, Vol.26, No.
7, 1977 1848-1849). Therefore, the number of repeated zones can be obtained using FIG. FIG. 13 assumes that the antenna height of the wireless base station is 70 m and the antenna height of the mobile wireless device is 1.5, assuming propagation in an urban area on a smooth ground.
m, the frequency used is 800 MHz, the vertical axis represents the propagation loss (dB) when transmitting and receiving with an antenna having a dipole ratio gain of 0 dB, and the horizontal axis represents the distance (km) from the radio base station.

According to FIG. 13, the point where the propagation loss is further larger by 24 dB is 25 km from the radio base station, compared with the case where the distance from the radio base station is 5 km. Therefore, it is necessary to place the wireless base stations 30 km apart. In this case, the number of repeating zones is 3 ⁻¹ (30/5) ² = 12.

The above is the so-called S in which one channel of the analog telephone signal described in Document 6 is mounted on one radio carrier.
As a result of CPC (Single Channel Per Carrier), how the number of repeating zones is small in the system according to the present invention will be described below. In this system, the modulation depth is 3.5 rad rms (for a tone signal of 1 kHz). Therefore, in a system in which the multiple load gain of the TCM-FM signal of the present invention is used to increase the FM modulation deviation, the same radio channel or adjacent radio channel is generally used as compared with a system not using this. You just have to prove that you have increased resistance to jamming.

First, the case where the carrier wave is FM-modulated with the TCM signal will be described, and the case where the carrier wave is compound-modulated with AM and FM will be described later.

Since the system using the TCM signal has not been put into practical use, the number of multiplex n is set to 10, 100 and 100.
The interference distortion is obtained when the values are changed in three ways of 0 and other system parameters are set to values as shown in FIG. Where T _t ... Frame length, T: time slot length, T _g : guard time length, n ... voice multiplicity T _o / T ... delay time due to the time length T _ALD ... multipath propagation of overlap ratio T _OVR ... overlap between the slots tolerance T _s ... sync pulse time length T _d ... data signal time slot length eta ... frame efficiency f _c Carrier frequency f _M Modulation signal frequency M _d Modulation depth Standard modulation deviation f _UM Modulation signal frequency of interference wave η = nT {n (T + T _g ) + (T _s + T _g ) + (T _d + T _g )} ^-1 .

When the same radio channel interference is used but the modulation depth is used as a parameter and the other design parameters shown in FIG. 14 are used, the characteristics as shown in FIG. 15 are obtained. That is, it can be seen that the signal-to-noise ratio (S / N) is improved as the modulation deviation Δf is increased at the same desired wave-to-interference wave ratio D / U. Alternatively, at the same S / N, for example, S / N = 25 dB, it can be understood that the larger the modulation deviation Δf is, the larger the interference wave can be endured.

Using this result, the number of repeated zones N
It is explained that the frequency can be reduced, and thus effective use of frequency can be achieved.

As described above, Δf = 3.5 (rad
rms) is the frequency shift of the NTT system, while those of the TCM-FM signal of the present invention are 7 for system 10, 14 for system 100 and 28 for system 1000 of FIG.
(Each rad rms). D according to NTT literature 5
Based on / U = 24 dB, apparently Δf = in FIG.
When 3.5 (rad rms) is the modulation depth of the NTT system, S / N = 40 dB is obtained. At this time, TCM-FM
Is used to find out what D / U value is required for the same S / N using FIG.
B, the same 100 obtains 8 dB, and the same 1000 obtains 4 dB. Therefore, from FIG. 13, the points where the propagation loss is larger by 16, 8, 4 dB than the case where the distance from the radio base station 30 is 5 km are 14, respectively, from the radio base station 30.
It is necessary to set the station at a distance of 7,6 km. In this case, the number of repeating zones is 3 ⁻¹ (14/5) ² = 2.6 3 ⁻¹ (7/5) ² = 0.65 3 ⁻¹ (6/5) ² = 0.48, respectively. .

From the above equation, the number of repeating zones is 3 or 2.
(There is no repeat zone less than 2). Therefore, it was found that the frequency utilization efficiency of the method according to the present invention is four times higher than that of the SCPC used in the NTT system or the like.

Next, in consideration of the recent narrowing of the carrier spacing, the case where the carrier spacing of the SCPC is 12.5 kHz will be examined. In this case, the frequency deviation Δf (modulation depth) of the TCM-FM signal of the present invention is the system 1 of FIG.
0 is 3.5, system 100 is 7, and system 1000 is 14 (each rad rms). TCM-FM is S /
When the amount of D / U required for N = 40 dB is obtained using FIG. 15, the system 10 obtains 28 dB, the system 100 obtains 16 dB, and the system 1000 obtains 8 dB. Therefore, from FIG. 13, points where the propagation loss is larger by 28, 16, 8 dB than in the case where the distance from the radio base station 30 is 5 km are 30 and 1 respectively from the radio base station 30.
It is necessary to set the station at a distance of 4,7 km. In this case, the number of repeating zones is 3 ⁻¹ (30/5) ² = 12 3 ⁻¹ (14/5) ² = 2.6 3 ⁻¹ (7/5) ² = 0.65.

The above description has been made on the case where the carrier is single-modulated by the TCM telephone signal. Next, the case of composite modulation will be described.

According to Document 4, it is described that when the same TCM telephone signal is subjected to composite modulation with a time difference of 10 msec, a diversity gain of 7 dB can be obtained. Therefore, this result is applied to the present invention.

In this case, the above-mentioned propagation loss magnitude 28,
This means that 16,8 dB may be reduced by 7 dB. Therefore, they are 21, 9, and 1 dB, respectively. Therefore, the number of repeating zones is 3 ⁻¹ (20/5) ² = 5.33 3 ⁻¹ (9/5) ² = 1.08 3 ⁻¹ (6/5) ² = 0.48.

From the above equation, the number of repeating zones is 5 or 2.
Below (there is no number of repeating zones less than 2), if diversity is not applied (12, 2.6, 0.
It can be seen that it is greatly reduced as compared with 65).

Next, it will be explained that the method of the present invention is superior in the interference resistance characteristic to the adjacent channel interference as compared with the SCPC. For that purpose, FIG. 15 may be used again.
That is, it can be considered that co-channel interference is the case where interference is the largest due to adjacent channel interference, and the fact that interference interference resistance increases as the amount of modulation deviation increases is similar to the case of adjacent channel interference. Therefore, it becomes possible to narrow the carrier spacing between adjacent channels, which also
It will contribute to the improvement of frequency utilization efficiency.

(3) System Configuration in the Case of Composite Signal Next, the system configuration and its operation in the case of using a composite modulation signal in which the carrier wave is amplitude and frequency modulated by the telephone signal will be described.

16 to 18 show a receiver 137 (FIG. 16) included in the mobile radio 100 (FIG. 2) and the radio base station 30 (FIG. 3) for explaining one embodiment of the present invention.
(A)), the wireless reception circuit 35 (FIG. 16B), the wireless transmission circuit 32 (FIG. 17) and the wireless transmission circuit 32B (FIG. 1).
8 shows a detailed configuration of 8). 16 to 18 will be described focusing on the points different from the corresponding FIGS. 2 and 3.

FIG. 16A shows a detailed circuit configuration of the receiving section 137 of the mobile wireless device 100. The wireless composite modulation signal received by the antenna unit is applied to the reception unit 137 via the reception mixer 136 and is divided into two parts, and a part of the amplitude modulation signal reception unit 161 operates by receiving the timing signal from the timing generator 142. The other part is input to the frequency modulation signal receiving section 162 which also operates by receiving the timing signal from the timing generator 142.
Then, these output signals are input to the mixing circuit 163. The mixing circuit 163 receives the quality of the input signal (SN ratio).
And select only good signals, or SN
It has the function of mixing both signals according to the ratio. The output of the mixing circuit 163 is divided into two, part of which is input to the speed restoration circuit 138 and the other part of which is input to the clock regenerator 141 (see FIG. 2).

FIG. 16B shows the detailed structure of the radio receiving circuit 35 of the radio base station 30.
After passing through the reception mixer 61, the signal received by the antenna part is divided into two parts, which are input to the amplitude modulation signal receiving part 62 and the other part to the frequency modulation signal receiving part 63. Then, these output signals are input to the mixing circuit 64. The mixing circuit 64 has a function of measuring the quality (SN ratio) of the input signal and selecting only a good signal, or mixing both signals according to the SN ratio. Mixing circuit 6
The output of No. 4 is divided into two, and one part is input to the signal selection circuit group 39 and the other part is input to the control unit 40 (see FIG. 3).

FIG. 17 shows the internal structure of the radio transmission circuit 32. The carrier frequency source 37 is on the left side, and the carrier wave from this is input to the frequency modulator 36. On the other hand, the signal from the signal allocation circuit group 52 is input to the frequency modulator 36 that operates under the control of the control unit 40, and the carrier wave becomes a frequency modulated wave. Next, the frequency modulated wave is input to the amplitude modulator 34 which operates under the control of the control unit 40. Here, the signal from the signal allocation circuit group 52 is input, and the frequency modulation wave is amplitude-modulated. Thus, the composite frequency-amplitude modulation is performed. And
This wireless composite modulated wave is input to the transmission mixer 33. Then, after being amplified by a power amplifier (not shown), it is transmitted from the antenna section to a large number of mobile radio devices 100.

FIG. 18 shows another embodiment 32B of the internal structure of the radio transmission circuit 32. There are two carrier frequency sources 37-1 and 37-2 on the left side, and the angular frequency Ω _a ,
Outputting carrier wave of Ω _b . This carrier frequency source 37-
The carrier wave from 1 is input to the frequency modulator 36 that operates under the control of the control unit 40, and is frequency-modulated by the signal from the signal allocation circuit group 52. On the other hand, the carrier frequency source 37
The carrier wave from -2 is input to the amplitude modulator 34 which operates under the control of the control unit 40, and is amplitude-modulated by the signal from the signal allocation circuit group 52. The outputs of the above two modulators are input to the transmission mixer 33, where the output frequency is converted into Ω ₁ = Ω _a + Ω _b , and at the same time, the composite modulation wave that has undergone frequency modulation and amplitude modulation is output. ..

Although the above description has been concerned with the composite modulation performed by the radio base station 30, the radio transmitter circuit 132 of the mobile radio device 100 also performs the composite modulation of the telephone signal and transmits it to the radio base station 30. Will be done.

In the transmission diversity described above, the phase of the TCM-converted telephone signal was not taken into consideration when performing the composite modulation. However, the effect of signal deterioration that occurs when a radio signal propagates in space is
They may be equivalent depending on the system parameters. In this case, it is possible to expect a time diversity effect (about 5 to 10 dB) by delaying either one of the amplitude modulation signal and the angle modulation signal using a delay circuit for about 10 to 100 msec. ..

In the transmission diversity described above, the modulation sideband characteristic of the composite modulation wave applied to the transmission antenna may be wider than the sideband characteristic of the single modulation wave depending on the system parameters. In this case, after obtaining the composite modulated wave, by the bandpass filter,
Adjacent radio channel by transmitting after reducing the sideband characteristic to the extent that it has a modulation sideband characteristic equivalent to the case where amplitude modulation or angle modulation is performed on one carrier with the same modulation signal It is possible to make the increase of radio wave interference to the system negligible.

[0106]

As is apparent from the above description, the transmission output level per radio channel is increased by the multiple load gain of the time division time compression multiplex signal and the diversity effect due to the complex modulation, which have not been clearly shown in the prior art. When the present invention is applied to the small zone system, the number of repeating zones is greatly reduced, so that the frequency utilization efficiency is dramatically improved and the power consumption is reduced. Be done. 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 of a mobile radio device for explaining the principle of the present invention.

FIG. 3 is a circuit configuration diagram of a radio base station for explaining the principle of the present invention.

FIG. 4 is a time slot structure diagram for explaining time slots used in the system of FIGS. 1 to 3;

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 time-compressed speech signal and control signal.

FIG. 9 is a flow chart showing a flow of a calling operation of the system of FIGS. 1 to 3.

10 is a flow chart showing a flow of a calling operation of the system of FIGS. 1 to 3 together with FIG. 9.

FIG. 11 is a configuration diagram showing a small zone configuration created by each wireless base station.

FIG. 12 is an electric field strength diagram showing electric field strengths of an interfered station and an interfering station for determining a frequency repeating distance.

FIG. 13 is a radio wave propagation characteristic diagram showing a radio wave propagation characteristic with respect to a distance from a radio base station.

FIG. 14 is a parameter numerical diagram showing an example of various parameters used in the time division time compression multiplex communication system.

FIG. 15 is an S / N diagram showing the S / N with respect to the change of D / U using the modulation deviation as a parameter.

16 is a detailed circuit configuration diagram of a receiving unit which is a component of the mobile wireless device shown in FIG. 2 and a wireless receiving circuit which is a component of the wireless base station shown in FIG.

FIG. 17 is a detailed circuit configuration diagram of a wireless transmission circuit which is a component of the wireless base station shown in FIG.

FIG. 18 is a detailed circuit configuration diagram of another embodiment of the wireless transmission circuit which is a component of the wireless base station shown 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 33 Transmission Mixer 34 Amplitude Modulator 35 Radio Reception Circuit 36 Frequency Modulator 37 Carrier Frequency Source 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 to 52-n signal allocation circuit 61 reception mixer 62 amplitude modulation signal reception unit 63 frequency modulation signal reception unit 64 mixing 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- , 121-2 Synthesizer 122-1 and 122-2 Switch 123 Transmission / reception gating controller 131 Speed conversion circuit 132 Radio transmission circuit 133 Transmission mixer 134 Transmission section 135 Radio reception circuit 136 Reception mixer 137 Reception section 138 Speed restoration circuit 141 Clock regenerator 142 Timing Generator 161 Amplitude Modulation Signal Reception Unit 162 Frequency Modulation Signal Reception Unit 163 Mixing Circuit

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. Time division movement using barrier exchange means (20) for exchanging communications with each mobile radio means (100) using radio channels carrying time-compressed delimited signals in time slots. In body communication, when a single carrier wave is amplitude-modulated and angle-modulated by the temporally-compressed and divided signal to obtain a composite modulated wave and transmitted, the modulation depth of the amplitude-modulation and the angle-modulation is obtained. Using the multiple load gain obtained by the composite modulated wave to reduce the transmission power of the composite modulated wave to reduce the number of repeating zones in the wireless service area. So Mel, time division communication method in a mobile communication system so as to determine.