JP2547126B2 - TDMA mobile communication terminal - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a TDMA mobile communication terminal such as an automobile telephone, a cordless telephone, a portable telephone or the like which employs a TDMA communication system and which a caller uses while moving.

[0002]

2. Description of the Related Art Conventionally, analog systems have been adopted in mobile communication terminals such as car telephones, and TDM will be available in the near future.
It is planned to shift to digital systems including A communication system.
In the Intelsat method, which is an example of the TDMA communication method, a terminal number, a control code, a transmission delay value, etc. are transmitted to each traffic station as a burst position control method.
Since this is communication between fixed stations in which details of the frequency to be transmitted and received and the burst position are determined in advance in the burst time plan (BTP), efficient communication is possible with simple control.

[0003]

However, in the conventional TDMA communication as described above, when a plurality of TDMA carriers having different frequencies are used and the invention is applied to the mobile communication adopting the demand assign method, As the information from the mobile terminal, information such as the telephone number of the other party of the call, the frequency to be transmitted and the frequency to be received as the information from the TDMA reference station, is required. It has a drawback that it cannot be applied to mobile terminals. Therefore, it is an object of the present invention to provide a TDMA mobile communication terminal capable of efficiently handling the above-mentioned information by using the TDMA method even if the mobile terminal adopts the demand assign method. .

[0004]

In order to achieve the above object, the present invention provides a TDMA type mobile communication terminal,
A transmission buffer that combines the encoded call signal and control information and adjusts the transmission timing in bit or symbol units, a transmission frequency conversion unit that modulates and transmits the burst signal from the transmission buffer, and a call signal from the reference station And a reception frequency converter for receiving control information, an SC processor for decoding control information sent from a reference station via a service channel (SC), and a call in the control information about the own station decoded by the SC processor. Burst control for changing the temporal position of a burst by controlling the transmission buffer based on a channel frequency and a channel number, changing the transmission frequency of the transmission frequency conversion unit, and changing the reception frequency of the reception frequency unit And a section. Therefore, it is possible to change the transmission / reception frequency, transmit the number of the other party of the call, etc. in addition to the control of the transmission delay value according to the control information of the reference burst, the transmission of the burst, the stoppage of the wave, etc. which have been performed conventionally. Therefore, it can be used as a mobile terminal for subscribers of various TDMA systems including other systems.

[0005]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 shows a TDMA mobile terminal (hereinafter,
1 shows a block configuration of a communication terminal 1. This communication terminal 1 includes, as shown in FIG. 1, a data processor 2 for encoding an analog call signal A such as voice data into a digital signal. , A preamble processor 3 which handles a called party number B relating to TDMA and control information for making a call, and an output signal from the data processor 2 and the preamble processor 3 are combined and transmission timing is adjusted in bit or symbol units The buffer 4, the SC processor 5 for processing the received control information carried by SC (control information transmission service channel) according to a predetermined protocol, and the control information and preamble processed by the SC processor 5. Outgoing signal C from processor 3 (call phase The transmission timing signal D is transmitted to the transmission buffer 4, the transmission frequency command E for channel allocation to the transmission frequency converter 9 and the reception frequency converter 10 for channel allocation to the reception frequency converter 10 based on The burst control unit 6 which sends the frequency command G, the modulation unit 7 which modulates the transmission information from the transmission buffer 4 and outputs it to the transmission frequency conversion unit 9, and the reception information from the reception frequency conversion unit 10 are demodulated. It is composed of a demodulation section 8 for transmitting a call signal.

FIG. 2 shows control information transmitted by the reference station and control information transmitted by the traffic station, and this control information is transmitted and received through an SC (service channel). FIG. 3 shows a format example of a reference burst and a traffic burst (a burst transmitted by a terminal is called a traffic burst). The reference burst is composed of CBTR, UW and SC, and the traffic burst is CBTR, UW, SC and traffic data. (Call signal). FIG.
FIG. 3 shows an example of a TDMA frame configuration in time series at each radio frequency, where RB1 and RB2 are reference bursts,
CH1 to CHn are traffic bursts, ACQ and WIN
DOW represents an acquisition window.

Each term used here will be described. CBT
R (Carrier and Bit Timing)
Recovery is a bit for carrier recovery for burst demodulation and bit for timing recovery, UW (U
"nique Word" is a bit used for phase determination and establishment of reception synchronization, SC is a service channel for transmission of control information, and CDC (Co
control and Delay Channel). These CBTR, UW and SC are called preambles. IAP1 (Initial Ac
acquisition Phase 1), IAP2 is T
The control signal sent from the reference burst when entering the DMA network, similarly SYNC is the control signal when entering the synchronization state, DNTX (Don't Tran).
smit) indicates a wave stop command when the call is completed or when there is a burst abnormality. Further, PRB is a main reference burst.
Indicates. Related to this, there is a sub-reference burst SRB used as a backup when the PRB cannot be received normally, but it is not particularly mentioned in this embodiment.

Next, the operation of the TDMA mobile communication terminal 1 having the above configuration will be described by taking the case of an operation for making a telephone call as an example. First, when the hook of the communication terminal 1 is raised and the communication destination number is dialed, this destination number is stored in the preamble processor 3 and a channel burst request signal (IAP1) addressed to all stations is issued. Is searched for the frequency of the reception frequency converter 10. Here, in the control information of the reference station transmission shown in FIG. 2, the terminal number 0000000 (addressed to all stations) and the control signal I
The AP1 and the control numerical value 135794 correspond to the information searched for.

Next, in the communication terminal 1, IA addressed to all stations
When the SC processor 5 detects that P1 has been received, transmission timing information is sent from the burst control unit 6 to the transmission buffer 4, and a short burst of only the preamble is received by the number of bits of the designated control value from the reception frame synchronization. The transmission frequency conversion unit 9 is also delayed in timing.
To transmit at a frequency corresponding to the reference burst. This transmission frequency is a frequency (pairing) corresponding to the frequency of the reference burst that received the IAP. At this time, if it is normal, the short burst is ACQ · WIND in FIG.
The time slot, which is the acquisition window of the TDMA frame indicating OW, is entered. That is, the transmission delay value that falls within the time slot is S of the reference burst from the reference station.
It has been sent in C. However, the control information of the reference station transmission is 1234567, TX CH, 12000 shown in FIG.
When there is a frequency change command such as 3,1234567, RX CH, 120010, the transmission frequency and the reception frequency are changed accordingly. Until then, the reception frequency of the received reference burst and the transmission frequency of its pair are not changed. Here, as shown in FIG. 2, the control information transmitted by the SC transmitted by the traffic station is its own station number,
It consists of the destination terminal number (including the subscriber's telephone number), the control signal currently being followed, and the reference burst currently being followed.
Of this control information, the essential information in this embodiment is only the terminal numbers of the own station and the partner station, and the rest of the information depends on the protocol of the TDMA network used at that time. Also, with respect to the terminal number portion of the partner station, the control numerical value sent after the connection is completed, for example, after receiving the SYNC signal, may be returned.

Next, the reference station checks the position of the short burst, the format of the SC, etc., and if there is no problem, the frequency and burst position (transmission delay value) of the vacant speech channel at that time are used as a reference for the terminal 1. It is sent in burst SC. Here, the information sent from the reference station corresponds to the terminal number 1234567, the control signal TX CH, and the control numerical value 120003 shown in FIG. This control value 120003 is No. 12 frequencies and channel CH3 are represented.

Next, the SC processor 5 of the communication terminal 1 decodes the control information sent by the SC and outputs it to the burst control unit 6, and the transmission output from the burst control unit 6 based on this control information. By supplying the timing signal D to the transmission buffer 4, the temporal position of the burst is changed. Further, the transmission frequency command E output from the burst control unit 6 is supplied to the transmission frequency conversion unit 9 to change the transmission frequency of the transmission frequency conversion unit 9. After that, the same procedure is followed to proceed to IAP2 and SYNC, and when SYNC is sent, the transmission buffer 4
A signal from the data processor 2 is also added to transmit a burst having a normal length. The traffic burst is processed by a protocol according to the command after x frames after always receiving the command of the reference burst and taking the time required for its processing. The value of x depends on the TDMA system. Next, after the transmission synchronization is established, the frequency of the speech channel to be received and the channel number are sent from the control station, and the reception frequency conversion unit 10 switches the reception frequency according to the channel accordingly. As a result, when the TDMA link is established and the carrier is cut off or the burst is abnormal due to the completion of the call, the operation in one TDMA network is completed by receiving the DNTX which is a wave stop command.

The SC processor 5 also has a function of making a majority decision on the control information sent a plurality of times and sending it to the burst control unit 6 as a command. in this case,
The control information transmitted by the reference station is transmitted 48 times 4 times, and if the SC bit of one burst is 24 bits, the majority decision is made by the bits transmitted over 8 frames. Although the above description has described the transmission (calling) from the terminal, when the terminal receives (calls in), the frequency of the reception frequency conversion unit 10 described first is searched and the IAP1 is transmitted to all stations. By performing the other operations at the time of calling except the operation of searching for a burst, the terminal can receive the call. That is, when the terminal 1 is in the standby state with the power turned on, the terminal 1 is in the state of searching for the reference burst in which the IAP1 addressed to the own station is issued, and after receiving the IAP1 addressed to the own station, all terminals when calling The same operation as after receiving the destination IAP1 is performed. That is,
The fact that the IAP1 addressed to the own station is transmitted from the reference burst means that there is an incoming call to the own station, that is, the mobile communication terminal. Therefore, in such a communication terminal,
It can be applied as it is to a communication terminal adopting various TDMA methods such as a demand assign method.

[0013]

As described above, according to the present invention, the communication destination number can be sent as the control information and the transmission and reception frequencies can be changed according to the control information of the reference burst. Therefore, various types including the SSTDMA system can be used. TDMA
It can be used as a mobile communication terminal for subscribers of the system.

[Brief description of drawings]

FIG. 1 is a block diagram of a mobile communication terminal based on a TDMA system according to an embodiment of the present invention.

FIG. 2 is a diagram showing control information for reference station transmission and traffic station transmission.

FIG. 3 is a diagram showing formats of a reference burst and a traffic burst.

FIG. 4 is a configuration diagram of a TDMA frame.

[Explanation of symbols]

 1 TDMA mobile communication terminal 5 SC processor 6 burst control unit 9, 10 frequency conversion unit

Claims (1)

(57) [Claims] 1. A mobile communication terminal of the TDMA scheme, as well as synthesized speech signals and control information encoded
Match transmission timing in bit or symbol units
Transmit buffer and burst signal from the transmit buffer are modulated and transmitted
And a reception frequency that receives the call signal and control information from the reference station.
Sent from the number converter and the reference station via the service channel (SC)
And SC processor of coming control information decrypt, based on the speech channel frequency and channel number in the control information related to the local station, which is decoded by the SC processor
When burst occurs by controlling the transmission buffer
The transmission position of the transmission frequency conversion unit while changing the interim position.
Reception frequency of the reception frequency section
TDMA mobile communication terminal, characterized in that it and a burst control unit for changing the.