JP4533183B2 - Digital mobile communication system - Google Patents

Description

  The present invention relates to a digital mobile communication system, and more particularly to a digital mobile communication system used for emergency calls and the like.

  A digital radio communication system currently in practical use, for example, a time division multiplex digital radio communication system (see, for example, Patent Document 1), as shown in FIG. 7, a communication area 703 between the base station 701 and the base station 701 ( Alternatively, it is also referred to as a communication zone.) Communication connection service with a plurality of mobile stations 702-1, 702-2,... (Referred to collectively as mobile stations 702) or mobile This is a system configured to perform an inter-mobile station communication connection service in which a station 702-1 and a mobile station 702-2 communicate with each other via a base station 701. In general, a plurality of base stations 701 are installed, and the plurality of base stations are connected to a central station (not shown) via a microwave multiplex line or a digital dedicated line. A system configuration that manages a plurality of base stations is common. However, in this example, only one base station 701 and mobile stations 702-1 and 702-2 are shown for simplicity of explanation. The base station 701 is provided with a line control device for performing call control from the mobile station 702 or control for setting a communication route.

  Thus, the standards for digital radio systems in Japan, such as municipal digital mobile communication systems, are based on the ARIB (Association of Radio Industries and Businesses) Standard (Publisher Association of Radio Industries Association) (hereinafter referred to as ARIB STD). It has been established. FIG. 9 shows radio carrier frequency allocation permitted for use in this system. In FIG. 9, 112 waves (f1, f2,...) Are recognized in the upstream direction, that is, in the direction from the mobile station to the base station, with a frequency band of one wave being 25 KHz width based on 262 MHz. . Also, in the downlink direction, that is, in the direction from the base station to the mobile station, the frequency band of one wave is 25 KHz width and 112 waves (F1, F2,... ) Is allowed. Accordingly, in the communication of the digital wireless communication system, the frequencies in the upstream direction f1, f2,..., The downstream directions F1, F2,. Each system can use one or a plurality of radio carriers as control carriers and the rest as communication carriers according to the scale.

  Furthermore, each radio carrier is divided into frames (frame length: 40 ms) as shown in FIG. 10, and the frames are further divided into four slots (1 slot length: 10 ms). These four slots will be referred to as channel 1 (CH1),... Channel 4 (CH4). For example, a control channel C and a communication channel S are allocated to this channel. Here, one frame is 40 ms, for example. The control channel C is a channel that performs connection control of a wireless line, and the communication channel S is a channel that performs telephone calls and data communication. A carrier including one or more control channels is referred to as a control carrier, and a carrier constituted only by communication channels is referred to as a communication carrier.

  A case where the base station and the mobile station communicate with each other by using the communication wireless carrier as described above, for example, by the press talk method will be described with reference to FIG. FIG. 8 is a diagram for explaining the operation when the base station 701 and the mobile station 702 communicate with each other. In FIG. 8, FIG. 8A shows a frame and channel configuration in the case where communication is performed from the base station 701 to the mobile station 702-1 using the downlink radio carrier F1. FIG. 8B shows a frame and channel configuration when communication is performed from the mobile station 702-1 to the base station 701 using the uplink radio carrier f1. FIG. 8C shows transmission / reception timing of the mobile station, RX indicates a reception period, TX indicates a transmission period, and I indicates an idle period. This is a so-called press-talk type digital mobile communication system that uses two frequencies f1 and F1 for uplink and downlink, but does not use a duplexer on the mobile station side. Also called system. FIG. 8 shows a case where control operations such as establishment of a communication path and allocation of a use channel are completed and a communication path between the base station 701 and the mobile station 702 is established.

  First, in FIG. 8A, when a call is made from the base station 701 to the mobile station 702-1, the downlink radio carrier F1 is used, and the channel number used in that case is CH1 (CH1 indicated by shading). The base station 701 transmits a signal to the mobile station 702-1 using the channel CH1 of the downlink radio carrier F1. In this case, the mobile station 702-1 receives the communication on the channel CH1 of the base station 701 at the reception timing RX (indicated by the slot RX) as shown in FIG. 8C.

  On the other hand, in the case of communication from the mobile station 702-1 to the base station 701, the transmission / reception offset between the frame timing of the base station 701 and the frame timing of the mobile station 702-1 is determined as 20 ms in the above-described ARIB STD. ing. Therefore, transmission of the mobile station 702-1 is performed using the channel CH1 of the uplink radio carrier f1 at the transmission timing TX (indicated by the slot TX) of the mobile station 702-1.

  As described above, the digital communication system of the press talk system that does not use a duplexer in the mobile station 702 uses two frequencies of the uplink radio carrier f1 and the downlink radio carrier F1, and further, for example, one type of voice Only communication is possible. In addition, a radio using a duplexer can transmit and receive simultaneously between a base station and a mobile station using two frequencies of an uplink radio carrier f1 and a downlink radio carrier F1, but the duplexer Therefore, the weight is heavy and the cost is high, so it is not suitable for a mobile station. Particularly, it is not suitable for a portable mobile radio. Therefore, realization of a digital mobile communication system with high radio frequency utilization efficiency, small size, light weight, and capable of transmitting many kinds of information such as voice communication information, control channel information and data transmission information. Is desired.

JP 2001-309437 A

  In a press talk type digital mobile communication system that does not use a duplexer in a mobile station, two frequencies of an uplink radio carrier f1 and a downlink radio carrier F1 are used, and only one type of, for example, voice communication can be performed. Therefore, it is desired to realize a digital mobile communication system that has high use efficiency of radio frequency, is small and light, and can transmit many kinds of information.

  An object of the present invention is to provide a digital mobile communication system having high radio frequency utilization efficiency.

  Another object of the present invention is to provide a digital mobile communication system capable of transmitting a plurality of types of information at one frequency.

  Another object of the present invention is to provide a digital mobile communication system which is a small and lightweight wireless device and has high utilization efficiency of radio frequency.

  Still another object of the present invention is to provide a digital mobile communication system capable of simultaneously transmitting / receiving a plurality of types of information at one frequency.

The digital mobile communication system according to the present invention is a digital mobile communication system in which a base station and a mobile station perform wireless communication with a wireless carrier configured by repeating a predetermined channel configuration including a control channel slot and a plurality of communication channel slots. The base station transmits information indicating the channel configuration and information indicating a plurality of transmission / reception timings in a unit frame of the radio carrier to the mobile station using the control channel slot. The transmission / reception timing is controlled based on the information indicating the channel configuration received from the base station and the information indicating the plurality of transmission / reception timings, and the base station and the mobile station perform a plurality of communications using a plurality of communication slots. Set to do .

In the digital mobile communication system of the present invention, the base station includes a first storage unit, and is configured to store the channel configuration in the first storage unit .

In the digital mobile communication system of the present invention, the mobile station has a second storage unit, and is configured to store a plurality of types of channel configurations and the transmission / reception timings in the second storage unit. Yes.

In the digital mobile communication system of the present invention, the base station and the mobile station are configured to perform voice communication and data communication as the plurality of communications .

  In the digital mobile communication system of the present invention, the base station uses the control channel slot to control the transmission / reception timing of the mobile station and the transmission channel from the mobile station to match the transmission / reception timing of the base station. It is configured to transmit a signal.

  In the digital mobile communication system of the present invention, the mobile station has means for changing transmission / reception timing of the mobile station and a transmission channel from the mobile station. A digital mobile communication system characterized by changing transmission / reception timing of the mobile station and a transmission channel from the mobile station based on a control signal for matching transmission / reception timing.

  As described above, according to the present invention, since a plurality of types of information can be transmitted at one frequency, the radio frequency utilization efficiency is high. In addition, since it is not necessary to use a duplexer, a small and lightweight wireless device can be realized, and in particular, a digital mobile communication system that can use a portable wireless device can be realized. Further, there is an advantage that a digital mobile communication system capable of simultaneously transmitting / receiving a plurality of types of information at one frequency can be realized.

  Hereinafter, the present invention will be described in detail with reference to the drawings. FIG. 2 is a block diagram showing a schematic configuration of a base station radio used in the present invention. In FIG. 2, reference numeral 201 denotes a base station radio, and this base station radio has a transmission / reception function. Reference numeral 202 denotes a base station, which corresponds to the base station 701 shown in FIG. The base station 202 may be configured integrally with the base station radio 201 or may be configured separately as shown in FIG. The base station 202 includes a central processing unit 203, a display unit 204, and an operation unit 205. The central processing unit 203 includes a slot allocation unit 206 and a storage unit 207, and the slot allocation unit 206 has a function of performing slot allocation that is characteristic of the present invention, which will be described later. The central processing unit 203 is generally composed of a personal computer (also referred to as a CPU) and functions to control the entire system of the digital mobile communication system such as a communication connection service between the base station 701 and the mobile station 702. .

3, (corresponding to the mobile station 702.) Mobile station radio transceiver 300 for use in the present invention is a block diagram showing the schematic configuration of, corresponding to the mobile station 70 2 shown in FIG. In FIG. 3, first, when the mobile station radio 300 is set to the reception state, a press talk switch (not shown) is switched to reception. As a result, the received signal from the base station 202 is given to the demodulating unit 304 via the antenna 301, the switching unit 302 (configured by a switch for switching to reception), and the receiving unit 303, and demodulated. Based on the demodulated signal, the slot allocation unit 305 passes the output according to the channel (also referred to as a slot) transmitted from the base station 202 to the control unit 306. The control unit 306 operates the wireless device 300 as a receiver by switching the press talk switch to reception. The control unit 306 controls the mobile station radio 300 as a whole in accordance with an instruction from the key input unit 311 and a control program in the memory 307. Further, for the output demodulated by the demodulation unit 304, the control unit 306 displays information such as necessary data on the display unit 308, or the demodulated audio signal is output as audio from the audio output unit 309, for example, a speaker. Output.

  Next, when operating the mobile station radio 300 as a transmitter, the press talk switch is switched to transmission. As a result, the control unit 306 operates the wireless device 300 as a transmitter. As a result, the control unit 306 delivers voice input information from the voice input unit 310, for example, a microphone, to the slot allocation unit 305. In the slot allocating unit 305, the voice information input delivered from the control unit 306 is modulated by a predetermined channel in accordance with channel (also referred to as a slot) information sent from the base station 202 previously determined based on the demodulated output. Deliver to unit 312. The signal modulated by the modulation unit 312 is transmitted from the antenna 301 to the base station 202 via the transmission unit 313 and the switching unit 302 (configured by a switch that switches to transmission).

  Hereinafter, channel slot configurations of base station 202 shown in FIG. 2 and mobile station radio 300 shown in FIG. 3 will be described with reference to FIG. FIG. 1 shows that the base station 202 and the mobile station radio 300 when the radio carrier used between the base station 202 and the mobile station radio 300 is operating at one radio frequency (radio carrier) of F1, for example. It is a figure which shows the channel configuration and mobile station radio transmission / reception timing. FIG. 1A shows a frame and channel configuration when communication is performed using a downlink radio carrier F 1 from the base station 202 to the mobile station radio 300. Here, Ach, Bch, Cch, and Dch indicate channel slots (ch), respectively, and correspond to the slots shown in FIG. Each channel slot is assigned a function unique to the channel slot. In other words, for example, emergency fixed communication channels (physical channels) are assigned to Ach and Bch. For example, emergency voice communication such as 110 call, 119 call, etc. is assigned. Cch is a control channel slot and transmits channel control information and the like as described later. Dch is a data communication channel slot. And each channel slot which comprises 1 frame (it consists of 4 slots) is arranged in order of Ach, Dch, Bch, Cch. Such a fixed channel slot is generated in the central processing unit 203 of the base station 202 shown in FIG. That is, the storage unit 207 of the central processing unit 203 stores Ach, Dch, Bch, and Cch in this order in units of one frame like the base station channel slot (ch) shown in FIG. Then, the slot allocation unit 206 allocates each channel slot in the order of Ach, Dch, Bch, and Cch stored in the storage unit 207 in synchronization with the frame synchronization signal FS of the central processing unit 203, and from the radio 201 to the mobile station Transmit to the radio 300. As a result, the radio carrier F1 from the base station 202 to the mobile station radio 300 is transmitted as a channel slot configuration as shown in FIG.

  In mobile station radio 300, a signal having a channel slot configuration as shown in FIG. 1A is passed to control section 306 via antenna 301, receiving section 303, demodulating section 304, and slot assigning section 305. In the control unit 306, transmission / reception timing is RX2 (reception period), TX1 (as shown in FIG. 1C) for each channel slot configuration of Ach, Dch, Bch, and Cch as shown in FIG. The receiver is controlled so that the transmission period), TX2 (transmission period), and RX1 (reception period). For the transmission signal from mobile station radio 300, control section 306 controls slot allocation section 305 in accordance with the timing and order in accordance with the base station channel slot configuration received from base station 202, as shown in FIG. As shown, channel slots are assigned so that the channel slot configuration transmitted from the mobile station radio 300 to the base station 202 becomes a Bch, Cch, Ach, and Dch channel configuration for each frame period. That is, since the transmission / reception offset determined by ARIB STD is 20 ms, the channel slot configuration shown in FIG. 1B is different from the channel slot configuration shown in FIG. It has become.

  Next, communication operation between base station 202 and mobile station radio 300 in the channel slot configuration shown in FIG. 1 will be described. First, when an emergency occurs, the base station 202 receives an emergency call, for example, voice 119 at the timing of Ach by telephone or the like, and this content is transmitted to the downlink radio carrier F1 as shown in FIG. At the timing of Ach, the data is transmitted to the mobile station radio 300 shown in FIG. At this time, since the mobile station radio 300 is in the reception period RX2, the mobile station radio 300 can receive the 119th audio signal from the base station 202.

  On the other hand, the base station 202 uses the downlink radio carrier F1 separately from Ach and uses the control channel slot Cch in FIG. 1A to control information for changing the channel configuration of the mobile station 300 and the transmission / reception timing of the mobile station. The CI is sent to the mobile station radio 300. The control information CI sent from the control station 202 is supplied to the control unit 306 of the mobile station radio 300, and for example, the control information CI is displayed on the display unit 308. This display content is, for example, control information CI that instructs the transmission / reception timing of the mobile station radio 300 to be RX1, RX2, TX1, TX2 as shown in FIG. Upon receiving this control information CI, the operator of the mobile station radio 300 operates the key input unit 311 to control the control unit 306, and changes the frame and channel slot configuration and transmission / reception timing of the mobile station radio 300. The mobile station radio 300 is controlled so as to have the relationships shown in FIGS. 4 (A), 4 (B), and 4 (C).

  Here, an example of a method in which the mobile station radio 300 sets the uplink channel configuration and transmission / reception timing shown in FIGS. 4B and 4C based on the control information CI sent from the base station 202 is shown in FIG. Will be described. FIG. 12A shows a frame synchronization signal of mobile station radio 300. FIG. 12B shows a channel configuration per frame of a signal transmitted from the mobile station radio 300 to the base station 202, and this configuration is stored in the memory 307. FIG. 12C shows transmission / reception timing per frame of the mobile station radio 300, and this configuration is also stored in the memory 307. Note that the configurations shown in FIGS. 12B and 12C are examples, and for example, the channel configurations and transmission / reception timings shown in FIGS. 5 and 6 described later are similarly stored. For example, in order to set the mobile station radio 300 to the channel configuration and transmission / reception timing shown in FIGS. 4B and 4C, the mobile station radio 300 transmits control information sent from the base station 202. The channel configuration shown in FIG. 12B and the transmission / reception timing shown in FIG. 12C are read from the memory 307 according to the contents of the CI, and the mobile station radio is controlled by controlling the slot allocation unit 305 based on the read contents. The uplink F1 channel configuration of 300 can be shown in FIG. 4B, and the transmission / reception timing can be changed to FIG. 4C by controlling the control unit 306. Needless to say, reading from the memory 307 is performed in synchronization with the frame synchronization signal shown in FIG. In order to switch the operation of the mobile station radio 300 according to the contents of the control information CI in this way, the operator operates the key input unit 311 and operates based on an instruction displayed on the display unit 308. However, the control unit 306 can detect the control information CI and automatically perform the switching operation.

  As a result, emergency voice information from the base station 202 is received from the Ach of the base station 202 during the reception period RX1 of the mobile station radio 300, and data such as character information from the base station 202 is used as message information. The Dch of the station 202 is transmitted to the mobile station radio 300, and this message information is received in the reception period RX2 of the mobile station radio 300. On the other hand, data such as emergency voice information and character information is transmitted from the mobile station radio 300 using Ach and Dch from the mobile station radio 300 to the base station 202 in the transmission periods TX1 and TX2 of the mobile station radio 300. Can send. Although both are the same channel, there is no interference because the transmission / reception offset is shifted by 2 time slots (40 ms). The above operation is repeated for each frame.

  As described above, when the frame and channel slot configuration between the base station 202 and the mobile station radio 300 and the transmission / reception timing of the mobile station are determined as shown in FIG. 1, the frame, channel slot configuration and movement at the time of both operations are determined. The transmission / reception timing of the station radio can be in the relationship shown in FIG. 4, and even if the base station 202 is in voice communication with the mobile station radio 300 using one radio carrier F1, the base station 202 and the mobile station radio 300 Data such as character information can be transmitted between the two. Therefore, in the case of emergency communication, it is possible to realize a digital mobile communication system capable of transmitting emergency voice communication and necessary character information and various data with one wireless carrier.

  FIG. 5 is a diagram for explaining the operation of another embodiment of the present invention. As shown in FIG. 5A, in the channel slot configuration of one frame of transmission of the base station 202, the arrangement of the channel slots is Bch, Cch, Ach, Dch, and the transmission / reception timing of the mobile station radio is If it is RX1, RX2, TX1, TX2 in one frame, emergency voice information from the base station 202 is sent to the mobile station radio 300 using Bch. At this time, since the mobile station radio 300 is in the reception period RX1, the mobile station radio 300 can receive emergency voice information from the base station 202. On the other hand, the base station 202 transmits the channel control information CI to the mobile station radio 300 using Cch as in the above embodiment. At this time, since the mobile station radio 300 is in the reception period RX2, the channel control information CI from the mobile station radio 300 can be received, supplied to the control unit 306, and displayed on the display unit 308. The operator sees this display and operates, for example, the key input unit 311 to set the channel slot configuration of the mobile station radio 300 to the transmission of the mobile station radio 300 as shown in FIG. The channel configurations Bch and Cch corresponding to the periods TX1 and TX2 can be used. Therefore, in the case of the frame and channel slot configuration as shown in FIG. 5, it is possible to transmit voice information and control information between the base station 202 and the mobile station radio 300 using one radio carrier F1. It becomes.

  FIG. 6 is a diagram for explaining the operation of still another embodiment of the present invention. As shown in FIG. 6A, in the channel slot configuration of one frame of transmission of the base station 202, the arrangement of the channel slots is Bch, Cch, Ach, Dch, and the transmission / reception timing of the mobile station radio is Assume that RX1, RX2, TX1, and TX2 are within one frame as shown in FIG. In this case, emergency voice information from the base station 202 is sent to the mobile station radio 300 using Bch. At this time, since the mobile station radio 300 is in the reception period RX1, the mobile station 300 can receive emergency voice information from the base station 202. On the other hand, the base station 202 transmits the channel control information CI to the mobile station radio 300 using Cch as in the above embodiment. At this time, since the mobile station radio 300 is in the reception period RX2, the channel control information CI from the mobile station radio 300 can be received, supplied to the control unit 306, and displayed on the display unit 308. The operator sees this display and operates, for example, the key input unit 311 to change the channel slot configuration of the mobile station radio 300 to Ach, Dch, Bch, Cch as shown in FIG. At the same time, the transmission / reception timing is instructed to be RX2, TX1, TX2, RX1. As a result, the mobile station radio 300 has transmission channel slots Dch and Bch corresponding to the transmission periods TX1 and TX2. Therefore, in this case, data such as voice information and character information can be transmitted between the base station 202 and the mobile station radio 300 using one radio carrier F1.

  In the embodiment of the present invention, one frame has been described as having a four-channel configuration. However, in order to send a large amount of information, it is possible to have a channel configuration of four or more channels, and a plurality of types of information at one frequency. Can be transmitted, so that the use efficiency of the radio frequency is high, and since there is no need to use a duplexer, a small and lightweight radio can be realized, and in particular, a digital mobile communication system that can use a portable radio realizable. Further, although the transmission at one frequency has been described, it is needless to say that the concept of the present invention can transmit more information when applied to a radio device using two frequencies.

  Although the present invention has been described in detail above, the present invention is not limited to the embodiments of the digital mobile communication system described herein, and can be widely applied to other digital mobile communication systems. Needless to say.

It is a figure for demonstrating operation | movement of one Example of this invention. The block diagram of schematic structure of the base station used by this invention is shown. 1 is a block diagram of a schematic configuration of a mobile station used in the present invention. It is a figure for demonstrating operation | movement of one Example of this invention. It is a figure for demonstrating operation | movement of other one Example of this invention. It is a figure for demonstrating operation | movement of further another Example of this invention. It is a figure for demonstrating schematic structure of the conventional digital mobile communication system. It is a figure for demonstrating operation | movement of the conventional digital mobile communication system. It is a figure for demonstrating the frequency band used by this invention. It is a figure for demonstrating the frame structure used by this invention. It is a figure for demonstrating the fixed channel structure of this invention. It is a figure for demonstrating the channel setting of the mobile station radio | wireless machine of this invention.

Explanation of symbols

  201: Radio unit 202, 701: Base station 203: Central processing unit 204, 308: Display unit 205: Operation unit 206, 305: Slot allocation unit 207: Storage unit 300, 702: Mobile station 301: Antenna 302: Switching unit 303: Receiving unit 304: Demodulating unit 306: Control unit 307: Memory 309: Audio output unit 310: Audio input unit 311: Key input unit 312: Modulation unit 313: Transmission unit, 703: Communication area.

Claims (4)

A digital mobile communication system in which a base station and a mobile station perform radio communication using a radio carrier configured by repetition of a predetermined channel configuration including a control channel slot and a plurality of communication channel slots . Information indicating the channel configuration and information indicating a plurality of transmission / reception timings in a unit frame of the radio carrier are transmitted to the mobile station using the control channel slot, and the mobile station receives the channel configuration received from the base station. Digital mobile communication characterized in that the base station and the mobile station perform a plurality of communications using a plurality of communication slots by controlling the transmission / reception timing based on the information indicating the information and the information indicating the plurality of transmission / reception timings system. 2. The digital mobile communication system according to claim 1 , wherein the base station includes a first storage unit, and the channel configuration is stored in the first storage unit . 3. The digital mobile communication system according to claim 1 , wherein the mobile station includes a second storage unit, and the plurality of types of channel configurations and the transmission / reception timings are stored in the second storage unit. 4. A digital mobile communication system. The digital mobile communication system according to any one of claims 1 to 3 , wherein the base station and the mobile station perform voice communication and data communication as the plurality of communications. system.

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