JPH0823319A - Synchronization control system - Google Patents

Abstract

PURPOSE:To provide the synchronization control system keeping established synchronization even on the occurrence of a temporary interruption or the like in a radio channel. CONSTITUTION:A mobile station 110 is provided with a synchronization pattern addition section 13 to add a synchronization pattern to a received signal, a synchronization pattern detection circuit 15 detecting the synchronization pattern in the received signal, and a control section 118 always monitoring the synchronization pattern detected by the synchronization pattern detection circuit 15 to control data to be sent/received at all times. A base station 120 is provided with synchronization pattern addition section 23, a synchronization pattern detection circuit 25 and a control section 128 similarly. When an established synchronization pattern S3 is not detected for a prescribed period, the control section 128 sends a synchronization establish request in the synchronization pattern S2 longer than the synchronization pattern S3 to the mobile station 110. Upon the receipt of the synchronization establish request, the control section 118 sends the signal in the synchronization pattern S2 for a prescribed period to take reception synchronization for a base station 120 and sends a signal again in the synchronization pattern S3.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a synchronous control system, and in particular to T
DM (Time Division Multiplex) method, TDMA (Ti
The present invention relates to a synchronization control method for maintaining the synchronization established between a base station and a mobile station in a wireless communication device or the like using the me Division Multiple Access) method.

[0002]

2. Description of the Related Art In TDMA-based communication, transmission signals transmitted by each station are synchronized on the transmission station side so that they do not interfere with each other on a radio line such as satellite communication, terrestrial radio communication and mobile communication. Need to take. This T
In order to synchronize in DMA communication, each transmitting station creates and inserts a specific synchronization pattern in a frame for transmitting a digital signal. The receiving station can establish synchronization between the transmitting and receiving stations by detecting this synchronization pattern.

By the way, particularly in the case of a communication mode in which a transmitting station or a receiving station moves, such as mobile communication, the wireless line is cut off depending on the location of the mobile station, or a synchronization pattern is erroneously detected or not detected. It may be more likely. In order to reduce the rate of false detection or non-detection, it is possible to deal with the problem to some extent by lengthening the synchronization pattern. However, if the synchronization pattern is lengthened, the frame efficiency will decrease.

On the other hand, if only a short synchronization pattern is used to improve frame efficiency, it becomes difficult to establish reception synchronization on the receiving station side.

Therefore, at first, a long synchronization pattern is used to facilitate reception synchronization to establish synchronization between the master station and slave station, and after establishing reception synchronization, a short synchronization pattern is used to improve frame efficiency. Has been adopted.

FIG. 2 is a diagram showing a schematic configuration of a conventional radio apparatus. Here, two of the mobile station 10 and the base station 20
Synchronization control between stations will be described.

The mobile station 10 encodes information input from the user information input terminal 11, an encoding unit 12, a synchronization pattern addition unit 13 that adds a synchronization pattern to the encoded data, and a synchronization pattern addition unit. A modulation / demodulation circuit 14 that modulates the data from 13 and transmits the data to the base station 20 and demodulates the reception signal from the base station 20, and a synchronization pattern detection circuit 15 that detects the synchronization pattern included in the reception signal.
The decoding unit 16 that decodes the received data based on the detected synchronization pattern, the user information output terminal 17 that outputs the decoded information, and the data that the encoding unit 12 and the decoding unit 16 transmit and receive. It has a control unit 18 for controlling and an antenna 19. On the other hand, the base station 20 also has a user information input terminal 21, an encoding unit 22, a synchronization pattern adding unit 23, a modulation / demodulation circuit 24, a synchronization pattern detection circuit 25, a decoding unit 26, a user information output terminal 27, and a control similar to those of the mobile station. It has a section 28 and an antenna 29.

The conventional operation will be described below.

The base station 20 maintains the transmission synchronization established with the mobile station 10 by continuously sending the synchronization pattern S1 to the mobile station 10. The mobile station 10 maintains the reception synchronization by the synchronization pattern detection circuit 15 continuing to detect the synchronization pattern S1 from the base station 20.

Here, when the mobile station 10 makes a random access to the base station 20, the sync pattern adding section 13 in the mobile station 10 generates a sync pattern S2 longer than the sync pattern S1 and passes through the modulation / demodulation circuit 14. To send.

In the base station 20, when the sync pattern detection circuit 25 detects the sync pattern S2, the mobile station 1
Synchronization will be established with 0 by the synchronization pattern S2.

When the mobile station 10 recognizes that the synchronization is established by the synchronization pattern S2, the synchronization pattern adding section 13 stops the generation of the synchronization pattern S2, generates the synchronization pattern S3 shorter than the synchronization pattern S2, and sends it. To do.

In the base station 20, when the synchronization pattern detection circuit 25 detects the synchronization pattern S3, the synchronization with the mobile station 10 is established and maintained by the synchronization pattern S3. After that, the synchronization pattern detection circuit 25
The timing signal for reception based on the synchronization pattern S3 is given to the decoding unit 26.

[0014]

However, in the above-mentioned conventional synchronization control method, when the wireless line is temporarily cut off after the synchronization is established in the short synchronization pattern S3, the short synchronization from the mobile station occurs. When the pattern S3 cannot be received by exceeding the number of forward protection stages of the synchronization pattern detection circuit on the base station side, reception synchronization on the base station side is lost. After that, even if the wireless line recovers from the interruption or the like and the synchronization pattern S3 from the mobile station reaches the base station, it is very difficult to establish reception synchronization at the base station with the short synchronization pattern S3. There was a problem that the wireless line was cut off.

The present invention has been made to solve the above problems, and an object of the present invention is to provide a synchronization control system capable of maintaining the established synchronization even if the wireless line is temporarily cut off. To provide.

[0016]

In order to achieve the above object, the synchronization control method according to the present invention detects a transmission / reception means for transmitting / receiving data and a synchronization pattern included in the data received by the transmission / reception means. A master station having at least one slave station and a sync pattern detecting means for controlling the data to be transmitted and received by the transmitting and receiving means, and a control means for controlling the data to be transmitted and received. In a synchronization control method for performing communication by synchronizing with a synchronization pattern established between the two, the control means in the main station constantly monitors the synchronization pattern detected by the synchronization pattern detection means, and establishes between the slave stations that are communication partners. If the first synchronization pattern that was being used cannot be detected for a certain period of time, synchronization with a second synchronization pattern that is longer than the first synchronization pattern is performed. The standing request is sent to the slave station, the control means in the slave station receives the synchronization establishment request, first after to send a second synchronization pattern
By transmitting the synchronization pattern of No. 1, the synchronization between the master station and the slave station is established again with the first synchronization pattern.

[0017]

According to the synchronization control method of the present invention having the above-described structure, the control means in the master station can detect the first synchronization pattern established between the slave stations as communication partners for a certain period of time. If not, the slave station is caused to send out a synchronization establishment request with a second synchronization pattern longer than the first synchronization pattern.

When the slave station receives the synchronization establishment request from the master station, the control means causes the synchronization pattern adding means to generate and add the second synchronization pattern, and then sends the second synchronization pattern. As a result, the main station establishes reception synchronization with the second synchronization pattern. After that, the control means causes the synchronization pattern adding means to stop the generation of the second synchronization pattern, and then generates and transmits the first synchronization pattern. As a result, the synchronization can be established again between the master station and the slave station by the first synchronization pattern shorter than the second synchronization pattern.

[0019]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT A preferred embodiment of the present invention will be described below with reference to the drawings. The same elements as those in the conventional example are designated by the same reference numerals.

FIG. 1 is a diagram showing a schematic configuration of a wireless device in this embodiment. In the present embodiment, a description will be given of an example of synchronous control between two mobile stations 110, which are slave stations, and a base station 120, which is a master station.

The mobile station 110 has a sync pattern adding section 13 as a sync pattern adding means for adding a sync pattern to a signal (data) to be transmitted to the base station 120, a modulation / demodulation circuit 14 as a transmitting / receiving means for transmitting / receiving data, A sync pattern detecting circuit 15 as a sync pattern detecting means for detecting a sync pattern included in the received signal, and a control unit 118 for constantly monitoring the sync pattern detected by the sync pattern detecting circuit 15 and controlling data to be transmitted / received. Have.

On the other hand, the base station 120 also has a synchronization pattern adding section 23 having the same function as the mobile station 110, and the modulation / demodulation circuit 2.
4, the synchronization pattern detection circuit 25 and the control unit 128. Note that the other components are the same as those in the conventional example, and a duplicate description will be omitted.

The characteristic feature of this embodiment is that when the base station 120 cannot detect the first synchronization pattern established with the mobile station 110 for a certain period of time, the first synchronization pattern is detected. It is to send a synchronization establishment request with a longer second synchronization pattern to the mobile station 110. Then, the reception synchronization is reestablished with the mobile station 110 by the second synchronization pattern, and then the synchronization is again established by the first synchronization pattern. in this way,
Once the reception synchronization is re-established with a long synchronization pattern that is easy to synchronize, and again with a short frame pattern with high frame efficiency, resynchronization initiated by the base station 120 can be performed even if a temporary disconnection of the wireless line occurs. In addition, it is possible to prevent disconnection of the wireless line and maintain synchronization with good frame efficiency.

The operation of this embodiment will be described below.

Mobile station 110 and base station 1 in this embodiment
The synchronization with 20 is established by the short synchronization pattern S3 that is the first synchronization pattern as described in the conventional example. At this time, the control unit 12 in the base station 120
Reference numeral 8 constantly monitors the synchronization pattern S3 of the detection signal by the synchronization pattern detection circuit 25 to maintain synchronization.

Here, when the wireless line is cut off due to some trouble and the synchronous pattern detecting circuit 25 cannot receive the synchronous pattern S3 for a certain period of time, the control unit 128 which monitors it receives the wireless line. Recognize that you are out of sync. Then, the control unit 128 controls the encoding unit 22.
On the other hand, a transmission request for a control message containing a synchronization establishment request by the second synchronization pattern S2, which is longer than the synchronization pattern S3, is issued. The encoding unit 22
The control message is transmitted to the mobile station 110 via the modulation / demodulation circuit 24.

In the mobile station 110, the decoding unit 16 is
The control message from the base station 120 received by the modulation / demodulation circuit 14 is decoded and transmitted to the control unit 118. The control unit 118 receives the synchronization establishment request based on the synchronization pattern S2 from the base station 120, recognizes the reception out-of-synchronization at the base station 120, and transmits the transmission data to the base station 120 to the synchronization pattern addition unit 13. An instruction is issued to add the synchronization pattern S2. Synchronization pattern addition unit 13
In accordance with this instruction, after transmitting with the synchronization pattern S2 for a certain period, the transmission is again performed with the synchronization pattern S3.

In the base station 120, the control unit 128 is
Reception synchronization is established by the synchronization pattern S2 from the mobile station 110 detected by the synchronization pattern detection circuit 25. That is, the above-mentioned fixed period during which the synchronization pattern adding unit 13 transmits the synchronization pattern S2 is a period during which reception synchronization can be established between the mobile station 110 and the base station 120 by the synchronization pattern S2. After that, when the synchronization pattern detection circuit 25 detects the synchronization pattern S3, the control unit 128 again synchronizes the synchronization pattern S3 between the mobile station 110 and the base station 120.
To establish synchronization.

In this way, according to this embodiment, even if the wireless line is temporarily cut off, the base station 12
At 0, the synchronization can be maintained by re-establishing the reception synchronization with the longer synchronization pattern S2 and then again establishing the synchronization with the shorter synchronization pattern S3. Therefore, it is possible to prevent disconnection of the wireless line and maintain communication with good frame efficiency. Further, the above synchronization control can be performed under the initiative of the base station 120.

In the present embodiment, the synchronous control between one mobile station 110 and one base station 120 has been described, but it is also possible to implement between a plurality of mobile stations and base station 120.

[0031]

As described above, according to the present invention, when the control means in the master station cannot detect the synchronization pattern for a certain period while constantly monitoring the synchronization pattern, the master station sends a response to the slave station. By sending a synchronization establishment request to notify the out-of-cycle, and the control means in the slave station attempts to establish resynchronization by transmitting a long second synchronization pattern when the synchronization establishment request is recognized. Therefore, even if the wireless line is temporarily cut off, it is possible to prevent disconnection of the wireless line.

In addition to the main station-initiated synchronization maintained in this manner, it is also possible to maintain frame-efficient communication.

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram of a wireless device for explaining an embodiment of a synchronization control system according to the present invention.

FIG. 2 is a schematic configuration diagram of a wireless device for explaining a conventional synchronization control method.

[Explanation of symbols]

 10, 110 Mobile station 12, 22 Encoding unit 13, 23 Synchronization pattern addition unit 14, 24 Modulation / demodulation circuit 15, 25 Synchronization pattern detection circuit 16, 26 Decoding unit 18, 28, 118, 128 Control unit 20, 120 Base station

Claims (1)

[Claims] 1. A transmission / reception unit for transmitting / receiving data, a synchronization pattern detection unit for detecting a synchronization pattern included in the data received by the transmission / reception unit, and a synchronization pattern addition for adding a synchronization pattern to the data transmitted by the transmission / reception unit. Means and a control means for controlling data to be transmitted and received, and a synchronization control method for performing communication by synchronizing with a synchronization pattern established between a master station and at least one or more slave stations, The control means constantly monitors the synchronization pattern detected by the synchronization pattern detection means, and if the first synchronization pattern established between the slave stations as communication partners cannot be detected for a certain period of time, the control means detects the first synchronization pattern from the first synchronization pattern. A synchronization establishment request in the long second synchronization pattern is transmitted to the slave station, and the control means in the slave station sets the synchronization establishment request. When the request is received, the first synchronization pattern is transmitted after the second synchronization pattern is transmitted, whereby the synchronization between the master station and the slave station is established again with the first synchronization pattern. Synchronous control method.