JP2784901B2 - Communication method in spread spectrum / demand assignment multiple access system and communication device used for the same - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION The present invention relates to a spread spectrum (S)
The present invention relates to a communication method in a S / demand assignment multiple access (DAMA) system and a communication device used for the communication method , and more particularly, to a communication method of DS communication using linear spreading (DS) and DS / FH (frequency hopping) hybrid communication.
The present invention relates to a method for reducing power consumption used in an S transceiver.

[0002]

2. Description of the Related Art The SS / DAMA system is a line allocation system in SS communication. In this system, a line is allocated using a control channel. FIG. 4 shows a communication system that requires error correction and concealment in the SS / DAMA system. The communication system shown in FIG. 4 includes a control station 1 for performing channel assignment,
It has a calling station 2 that makes a communication request and a called station 3 that is a communication partner of the calling station 2.

FIG. 5 shows a receiver section of a transceiver used in each of the control station 1, the calling station 2, and the called station 3. The receiver unit has a receiving unit 10 ', a demodulation unit 20', and a communication control circuit 30 '. The receiving unit 10 'includes an antenna 11, a radio frequency (RF) amplifier circuit 12, an intermediate frequency (IF) amplifier circuit 13, and a synchronization acquisition circuit 14'. Demodulation unit 2
0 'has a synchronization holding circuit 21', a despreading circuit 22 ', a data demodulation circuit 23', an error correction circuit 24 ', a concealment circuit 25', and a call detection circuit 26 '. Power is always supplied to each circuit constituting the demodulation unit 20 '.

[0004] In the communication system shown in FIG.
In 5 '(FIG. 5), it is necessary to release the secret and detect the call. Therefore, as shown in FIG. 5, the concealment circuit 25 'always releases the concealment, and the call detection circuit 26' behind the confidential circuit 25 'detects that the own station is called.

Next, a communication procedure (communication method) of a conventional communication system will be described with reference to FIG. 4 and FIG.

A. First, the calling station 2 transmits a communication request signal to the control station 1 using a control channel spreading code.

B. Control station 1 that has received the communication request signal
Determines, for the calling station 2 and the called station 3, one spreading code for a communication channel from among the spreading codes for unused communication channels other than the spreading code for the communication channel in use, and At the same time as changing and registering the communication channel spreading code as being used, the communication channel designation data indicating the determined communication channel spreading code is transmitted to the calling station 2 and the called station 3 using the control channel spreading code. .

C. The calling station 2 and the called station 3 complete the synchronization acquisition for the signal from the control station 1 in the above-mentioned b in the synchronization acquisition circuit 14 'for the control channel, and are synchronized by the synchronization holding circuit 21' in the rear demodulation unit 20 '. Are despread by the despreading circuit 22 'while the data demodulation circuit 2
3 ′ demodulates PSK-modulated data, which is the primary modulation, performs error correction such as Viterbi decoding in an error correction circuit 24 ′, deciphers data in a concealment circuit 25 ′, and releases a call detection circuit 26 ′.
To detect the final data. As a result, the spread code for the communication channel transmitted in b above is obtained as the final data.

D. The calling station 2 and the called station 3 perform communication using the communication channel spreading code obtained in c above.

E. When the communication d is completed, the calling station 2 transmits a communication end notification signal to the control station 1 by using the spreading code for the control channel.

F. The control station 1 that has received the communication end notification signal deletes the determined communication channel spreading code from the registered used communication channel spreading codes, and changes and registers the unused communication channel spreading code as an unused state.

[0012]

The above-mentioned conventional communication method has the following problems.

First, in the conventional communication system shown in FIG. 4, when the called station 3 is called on the control channel, the called station 3 does not know when it is called from the control station 1, so that the spread spectrum signal is always transmitted. Must be monitored. In order to detect the call, it is necessary to release the concealment in the concealment circuit 25 'and to power on and operate all the circuits of the demodulation units 20' up to the call detection circuit 26 'behind the concealment circuit 25'. Therefore, a small wireless device such as a manpack which requires low power consumption has problems such as an increase in battery weight and a reduction in use time.

The present invention has been made in view of such a problem, and has as its object to provide a demodulation unit with a power on / off function, perform power on save, and reduce power consumption during reception standby as much as possible. is there.

[0015]

To achieve the above object, a communication method according to the present invention comprises a control station for allocating a line, a calling station for making a communication request, and a communication partner of the calling station. A communication method in a spread spectrum / demand assignment multiple access system including a certain called station, wherein the calling station transmits a communication request signal to the control station using a control channel spreading code; Transmitting a synchronization acquisition signal for a short time using a pre-assigned spreading code unique to the called station specified in advance to the called station; and responding to the synchronization acquisition signal, Completing synchronization acquisition with the synchronization circuit of the called station;
After transmitting the synchronization acquisition signal, the control station, for the calling station and the called station, a plurality of unused states other than the used communication channel spreading code and the pre-assignment spreading code. One is determined from the communication channel spreading code, and the determined communication channel spreading code is changed and registered as being used, and at the same time, the determination is made to the calling station and the called station using the control channel spreading code. Transmitting communication channel designation data indicating the spread code for the communication channel, and after completing the synchronization acquisition, the called station powers on a demodulation unit behind the synchronization acquisition circuit to establish data synchronization. Obtaining the spread code for the determined communication channel by the calling station and the called station as demodulated data; and determining that the calling station and the called station are Performing communication using a spread code, and after the communication ends, the calling station transmits a communication end notification signal to the control station using the control channel spreading code; and responding to the communication end notification signal. Then, the control station deletes the determined communication channel spreading code from the registered communication channel spreading codes in use.

The communication device according to the invention, through which definitive in the spread spectrum / demand assignment multiple access scheme
A communication device used for the communication method, including a synchronization acquisition circuit, a receiving unit that receives a signal spread spectrum,
A demodulation unit having a power on / off function, demodulating a signal received by the reception unit, and a communication control circuit for powering on the demodulation unit when synchronization acquisition is completed by the synchronization acquisition circuit, The demodulation unit is a synchronization holding circuit that holds synchronization
A despreading circuit for despreading the received signal;
Data demodulation circuit that demodulates the signal despread by the spreading circuit
Path and the signal demodulated by the data demodulation circuit.
Error correction circuit for performing error correction and error correction by the error correction circuit.
A secret circuit for deciphering the corrected signal and a secret circuit
A call detection circuit that detects a call from a signal that is more confidential
And

[0017]

According to the present invention, immediately before the control station which performs channel assignment calls the called station based on the request of the calling station, the control station transmits the signal for a short period of time using a spreading signal with a spreading code unique to the called station. Since the line is allocated by the control channel for the line allocation, the SS / DAMA using the control channel is used.
In a communication system that requires error correction and concealment of a system, it is possible to reduce the power consumption of the called station during standby. That is, the power consumption of the called station during standby is reduced by reducing the operation time of each circuit (such as a concealment circuit) constituting the demodulation unit located behind the synchronization acquisition circuit as much as possible.

[0018]

Next, embodiments of the present invention will be described with reference to the drawings.

FIG. 1 is a diagram showing an SS / DAMA communication system to which a communication method according to the present invention is applied. The illustrated communication system includes a control station 1 that performs line allocation, a calling station 2 that has issued a communication request, and a called station 3 that is a communication partner of the calling station 2.

As shown in FIG. 2, the receiver unit of the radio (transceiver) used in the control station 1, calling station 2, and called station 3 in FIG. 20 and a communication control circuit 30. The receiving unit 10 includes an antenna 11 and an RF
Amplifying circuit 12, IF amplifying circuit 13, synchronization acquisition circuit 1
And 4. Power is always supplied to each circuit constituting the receiving unit 10. The demodulation unit 20 includes a synchronization holding circuit 21, a despreading circuit 22, a data demodulation circuit 23, an error correction circuit 24, a concealment circuit 25, and a call detection circuit 26. Each circuit constituting the demodulation unit 20 has a power on / off function, and the power on / off is controlled by the communication control circuit 30.

First, in the receiving unit 10, a signal subjected to spectrum spreading is received as a received signal. The received signal is input from the antenna 11 and is amplified and frequency-converted by the RF amplifier circuit 12 and the IF amplifier circuit 13. The frequency-converted signal is first called by the synchronization acquisition circuit 14 to detect whether the received signal is the same as the spreading code specified by the called station 3. Detect that That is, the synchronization acquisition circuit 14 includes a matched filter for the communication channel, and sets the matched filter for the communication channel to a predetermined spreading code unique to the called station 3.

The synchronization acquisition circuit 14 by the control channel is automatically operated, and the rear demodulation unit 20 (synchronization holding circuit 21, despreading circuit 22, data demodulation circuit 23, error correction circuit 24, concealment circuit 25, Call detection circuit 26)
In a power-on preparation state. That is, in the present invention, the call detection operation is performed by the synchronization acquisition circuit 14.

Referring to FIG. 3, the communication control circuit 30 comprises:
SS timing signal input detection circuit 31, power-on /
An off-control signal generation circuit 32 and a CPU circuit 33 are provided. The SS timing signal input detection circuit 31 inputs the SS timing signal from the synchronization acquisition circuit 14. The CPU circuit 33 sends a function control command to the power on / off control signal generation circuit 32. The power on / off control signal generation circuit 32 outputs a power on / off control signal to each of the circuits 21 to 26 constituting the demodulation unit 20.

Next, a communication procedure (communication method) according to the present invention will be described in detail with reference to FIGS.

[0025] First, the calling station 2 transmits a communication request signal to the control station 1 using a control channel spreading code.

[0026] Control station 1 that has received the communication request signal
Transmits a synchronization supplementary signal for a short time using a pre-assigned spreading code unique to the called station 3 specified in advance to the called station 3.

[0027] The called station 3 completes the synchronization acquisition for the above signal by the synchronization acquisition circuit 14 and immediately sets the state so that the synchronization acquisition circuit 14 using the control channel can start the function.

[0028] After the above-described procedure, the control station 1 instructs the calling station 2 and the called station 3 to transmit the unused communication channel spreading codes other than the used communication channel spreading code and the pre-assignment spreading code. From this, the communication channel spreading code to be used is determined, and the determined communication channel spreading code is changed and registered as being in use, and at the same time, the communication channel designation data indicating the determined communication channel spreading code is transmitted to the calling station 2 and It is transmitted to the called station 3 using the spreading code for the control channel.

[0029] The called station 3 sends the SS timing signal to the communication control circuit 30 when the synchronization acquisition for the signal from the control station 1 is completed by the synchronization acquisition circuit 14 for the control channel which has started functioning as described above. In response to the SS timing signal, the communication control circuit 30 includes a synchronization holding circuit 21, a despreading circuit 22, a data demodulation circuit 23,
Error correction circuit 24, concealment circuit 25, and call detection circuit 2
6 is powered on to establish data synchronization. Then, the calling station 2 and the called station 3 obtain the above communication channel spread code as demodulated data.

[0030] The calling station 2 and the called station 3 communicate using the communication channel spreading code obtained above.

[0031] When the above communication is completed, the calling station 2 transmits a communication end notification signal to the control station 1 using the control channel spreading code.

[0032] The control station 1 that has received the communication end notification signal deletes the determined communication channel spreading code from the registered used communication channel spreading codes, and changes and registers the unused communication channel spreading code as an unused state.

[0033]

As described above, according to the present invention, just before a control station that performs channel allocation calls a called station on a control channel based on a request from a calling station, the spreading unique to the called station specified in advance is performed. A signal for synchronization acquisition is transmitted for a short time using a code, and a demodulation unit (a synchronization holding circuit such as a DLL, a despreading circuit, a data demodulation circuit, an error correction circuit, Circuit and call detection circuit)
Is provided with an auto power on / off function, so that the spreading code unique to the called station that is specified in advance can be specified without hindering the non-fixing of the spreading code for the communication channel, which is an advantage of the DAMA system. There is an effect that it is difficult to be intercepted and it is possible to reduce the power consumption of the radio device that is waiting.

[Brief description of the drawings]

FIG. 1 is a block diagram illustrating an SS / DAMA communication system to which a communication method according to an embodiment of the present invention is applied.

FIG. 2 is a block diagram showing a configuration of a receiver unit of a transceiver used for each of a control station, a calling station, and a called station that constitute the communication system shown in FIG.

FIG. 3 is a block diagram illustrating a configuration of a communication control circuit of the receiver unit illustrated in FIG. 2;

FIG. 4 shows SS / DA for explaining a conventional communication method.
FIG. 2 is a block diagram illustrating a communication system of the MA system.

FIG. 5 is a block diagram showing a configuration of a receiver section of a transceiver used for each of a control station, a calling station, and a called station which constitute the conventional communication system shown in FIG.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 control station 2 calling station 3 called station 10 receiving unit 11 antenna 12 RF amplifier circuit 13 IF amplifier circuit 14 synchronization acquisition circuit 20 demodulation unit 21 synchronization holding circuit 22 despreading circuit 23 data demodulation circuit 24 error correction circuit 25 concealment circuit 26 Call detection circuit 30 Communication control circuit 31 SS timing signal input detection circuit 32 Power on / off control signal generation circuit 33 CPU circuit

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁶ , DB name) H04B 1/707 H04B 1/713

Claims (2)

(57) [Claims] 1. A communication method in a spread spectrum / demand assignment multiple access system including a control station for allocating a line, a calling station for making a communication request, and a called station for communicating with the calling station. In the above, the calling station transmits a communication request signal to the control station using a spreading code for a control channel, and the control station performs a pre-assignment specific to the called station specified in advance to the called station. Transmitting a synchronization acquisition signal for a short time using a spreading code; and, in response to the synchronization acquisition signal, the called station completing synchronization acquisition with a synchronization acquisition circuit of the called station. After transmitting the synchronization acquisition signal, the control station communicates to the calling station and the called station a plurality of unused communication channels other than the communication channel spreading code and the pre-assignment spreading code. channel One is determined from the spreading codes, and the determined communication channel spreading code is registered as being changed to “in use” and, at the same time, the determined communication channel is transmitted to the calling station and the called station using the control channel spreading code. Transmitting the communication channel designation data indicating the spreading code for use, and after completing the synchronization acquisition, the called station powers on a demodulation unit behind the synchronization acquisition circuit to establish data synchronization, and A calling station and the called station obtaining the determined spreading code for the communication channel as demodulated data; and a step of performing communication between the calling station and the called station using the obtained spreading code for the communication channel. And after the communication ends, the calling station transmits a communication end notification signal to the control station using the control channel spreading code; and responding to the communication end notification signal. The control station, from among the communication channel spread code in use is registered, a communication method in a spread spectrum / demand assignment multiple access system comprising the step of deleting a spreading code for communication channels with the determined. 2. A spread spectrum / demand assignment multiple access system communication device that is used <br/> the definitive communication method according to claim 1, wherein the synchronization acquisition circuit (14), spread spectrum A receiving unit (10) for receiving the received signal, a demodulating unit (20) having a power on / off function and demodulating the signal received by the receiving unit, , look including a power controller to power on the demodulator (30), said demodulator (20), the synchronization holding circuit for holding the synchronization
(21) and a despreading circuit for despreading the received signal.
(22) demodulating the signal despread by the despreading circuit
A data demodulation circuit (23) that performs
Error correction circuit that performs error correction on demodulated signals
(24) and the signal corrected by the error correction circuit.
A concealment circuit (25) for releasing concealment and concealment by the concealment circuit
Call detection circuit (26) for detecting a call from a signal obtained by solving
And a communication device.