JPS6230438A - Radio communication system - Google Patents

Abstract

PURPOSE:To attain efficient transmission by dividing transmission data into blocks, requesting retransmission of only a received block having an error after receiving the final block, and if the retransmission request is not answered, demanding the answer of the retransmission request. CONSTITUTION:A radio transmission equipment 10 on the transmission side divides transmission data stored in a buffer memory 4 into blocks in a control part 1 prior to the transmission of the data. Then, a connection request signal consisting of an access code or the like is transmitted from a radio modulation transmitting part 5. A radio communication equipment 20 on the receiving side receives the connection request signal, extracts the number of blocks of the transmitted data and transmits a connection response consisting of a code or the like indicating the capability of reception from the transmission part 5. Receiving the response, the transmission side transmits transmission data continuously. The receiving side stores blocks having no error in the buffer memory 4. Detecting an error, the receiving side extracts the block No. of the block having the error and transmits a retransmission request consisting of a retransmission request code and the block No. of the block having the error to the transmission side. When no retransmission request is returned, the transmission side retransmits only the data of the final block to demand the answer.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to a wireless communication device that performs data communication between a pair of wireless communication devices using a predetermined radio frequency.

[Technical Background of the Invention] Conventionally, wireless communication devices are known that perform voice communication using a predetermined radio frequency between a fixed station installed in an office or the like and a mobile station installed in a moving body such as a car. However, recently, a host computer is connected to the fixed station side,
A data terminal is also connected to the mobile station and required data is exchanged between the host computer and the data terminal.

In this case, since one of the stations is a mobile station, the quality of the wireless communication line is often very poor. Therefore, conventionally, transmission data is divided into a plurality of blocks in units of a predetermined number of data, and the data in each block is encoded according to a predetermined encoding rule and transmitted in block units, and the receiving side encodes the received data The line quality is improved by performing error checking on a block-by-block basis according to the error checking rule corresponding to the standard, and if there is an error, the sending side is requested to retransmit, and if there is no error, the transmission of the next block of data is requested. I'm trying to make up for the bad things.

[Problems with the Background Art] However, as described above, when data is transmitted and received while checking each other for data errors in blocks, it is necessary to perform operations such as reconfiguring the wireless line to switch between transmission and reception in blocks. , which increases the time required to complete transmission of all data and reduces transmission efficiency.

[Object of the Invention] The present invention was made in order to solve the above problems, and an object of the present invention is to provide a wireless communication method that can efficiently transmit transmission data in a short time.

[Summary of the Invention] The present invention provides that, prior to transmitting transmission data, a wireless communication device on the transmitting side divides the transmission data into a plurality of blocks in units of a predetermined number of data, and after transmitting data representing the number of divided blocks. , the data of each block is encoded according to a predetermined encoding rule and transmitted continuously up to the final block, and the receiving side wireless communication device encodes the data received from the transmitting side block by block according to the aforementioned encoding rule. Error checking is performed according to the error checking rules, and after the last block of data is received, retransmission is requested by transmitting the number data of the block in which an error was detected using a block consisting of a predetermined number of data units, and the sending side If a retransmission request is not returned within a predetermined time after sending the final block of data, the transmitting wireless communication device retransmits only the final block of data and returns a retransmission request. The above purpose is achieved by prompting the receiving side.

[Embodiment] FIG. 1 is a block diagram showing an embodiment of the present invention. In the figure, 10 is a wireless communication device on the fixed station side, and 2
0 is a wireless communication device on the mobile station side. These wireless communication devices 1 and 20 include a control section 1 that performs overall control for data communication, a communication control section 2 that transmits and receives control signals between the modulation and demodulation section 3 and the control section 1, and a communication control section 2 that converts transmission data into a predetermined code. A modulation/demodulation unit 3 encodes the received data in accordance with the general rule and decodes the encoded received data, a buffer memory 4 stores the transmitted data and received data, and modulates a carrier wave of a predetermined frequency with the encoded transmitted data. , a wireless modulation transmitter 5 that transmits from the antenna 8 via the transmission/reception switch 7;
The wireless reception demodulation section 6 demodulates encoded received data.

FIG. 2 is a flowchart showing an outline of the operation performed by the transmitting side wireless communication device in the above configuration, and FIG. 3 is a flowchart showing an outline of the operation performed by the receiving side wireless communication device.

Further, FIG. 4 is a diagram showing a sequence during data communication.

Here, the operation will be described assuming that the wireless communication device 10 on the fixed station side is the transmitting side and the wireless communication device 20 on the mobile station side is the receiving side.

First, the wireless communication device 10 on the transmitting side stores the buffer memory 4
Before transmitting the transmission data stored in , the transmission data is divided into a plurality of blocks in units of a predetermined number of data (for example, in units of 9 characters), and consecutive block numbers @ are assigned to the data a1 to ak of each block. Assign F1 to Fk. This process is executed by the control unit 1.

Next, as shown in FIG. 4, the calling code A, the destination station number B,
A connection request signal consisting of each piece of data corresponding to the number of blocks of transmission data is transmitted from the wireless modulation transmitter 5 (step 30>
. At this time, in order to monitor the response on the receiving side, a response monitoring timer for time T is started (step 31).

In response, the wireless communication device 2 on the receiving side that received the connection request
0 extracts the number K of blocks of transmission data and temporarily stores it in the buffer memory 4 (step 51), and then wirelessly modulates the connection response consisting of the own station number E to the number of blocks of receivable code C1 transmission data. It is transmitted from the transmitter 5 (step 52).

During this time, the sender is waiting for a connection response to be returned.
When the connection response is received (step 32), the transmission data stored in the buffer 7 memory 4 is continuously transmitted up to the first block (step 34). If a connection response is not returned even after T time has elapsed, the connection request is sent again (step 33).

Note that when transmitting data of each block, the transmitting side adds a block number Fr (=-t to K) to the beginning of the transmission data of each block, encodes it according to a predetermined encoding rule, and transmits it.

On the other hand, the receiving side continuously receives the received data of each block, detects errors in the received data block by block, and stores the block number in the buffer 7 memory 4 for the data of the block where no code error has occurred. The information is sequentially stored in the corresponding locations (steps 53 and 54). When the reception of data up to the first block is completed (step 56), the block number of the block in which the code error has been detected is extracted, and the code G of the retransmission request and the block number Fi of the block in which the code error has occurred are combined. A retransmission request consisting of the following is sent to the sending side (step 51).

In this case, the number of blocks for which retransmission requests can be made is p
(limited to within p<K>. This means that the length of data sent and received between the sending side and the receiving side is all constant, and the end of each block of data and the connection after sending a connection request are connected. This is because a timer monitors the time until a response is sent back and the time from when the last block of data is sent until a retransmission request is sent back, and the sending and receiving operations are performed reliably in a simple manner.

The transmitting side, which has received retransmission requests for a maximum of p blocks in this way, reads the data of the blocks for which retransmission requests have been requested from the buffer memory 4, and successively retransmits those blocks to the receiving side (step 39. 40). Then, the receiving side receives the retransmitted data block by block in the same way as the above-mentioned receiving operation, checks the data for errors, and if there is no error, stores the data in the memory area of the buffer memory 4 corresponding to the block of data. let In this case, if an error is again detected in the retransmitted data, or if there are still unreceived blocks that should be retransmitted in the retransmission request, the retransmission request is sent to the transmitting side again.

Note that if the receiving side has no errors in the data received from the transmitting side, it returns all block numbers Fi of the retransmission request to rOJ and returns it to the transmitting side.

On the other hand, after the sending side has finished transmitting the data up to the last block of the block for which the retransmission request was made, it starts a response monitoring timer (set time = T> (step 35), and the set time T of this timer If a retransmission request is not returned from the receiving side within the elapsed time period, only the last block of data is retransmitted and prompting the receiving side to return a retransmission request (step 37.
38>.

As described above, according to this embodiment, data corresponding to the number of blocks of transmission data is added to the connection request and transmitted, and then each block of data is transmitted successively up to the final block, and the receiving side If there is a block with a code error after receiving the data, a retransmission request is made only for that block, and the sending side retransmits the data. This reduces the number of wireless link setting operations and allows multiple blocks to be retransmitted. data can be transmitted in a short time, improving transmission efficiency. In addition, since the number of blocks of received data is known in advance on the receiving side, it is possible to easily determine whether or not all received data has been received, and it is also possible to ensure that preparations are made to receive the received data. You can leave it there.

Roughly speaking, even if there is no code error in the received data, a retransmission request with the block number Fi as rOJ is returned, so it is possible on the transmitting side to determine whether the transmitted data has been reliably received.

Additionally, if a retransmission request is not returned within a certain period of time, the last block of data is retransmitted to prompt the retransmission request, so the series of transmission and reception operations is completed without using any special control signals. This makes it possible to ensure data communication with mobile stations with poor line quality.

[Effects of the Invention] As explained above, according to the present invention, before transmitting the transmission data, the transmitting side wireless communication device divides the transmission data into a plurality of blocks in units of a predetermined number of data 7, and divides the transmission data into a plurality of blocks 7. After transmitting the data representing a number, the data in each block is encoded according to a predetermined encoding rule and transmitted continuously up to the final block, and the wireless communication device on the receiving side encodes the data received from the transmitting side block by block. Error checking is performed according to the error checking rule corresponding to the encoding rule, and retransmission is requested after receiving the final block of data only for blocks in which an error is detected, and the sending side retransmits the data of the corresponding block. If a retransmission request is not returned within a predetermined time after transmitting the last block of data, the transmitting side wireless communication device retransmits only the final block of data and prompts the receiving side to return the retransmission request. Transmission data can be efficiently transmitted and received in a short period of time, and moreover, without using special control signals.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing an embodiment of the present invention, FIG. 2 is a flowchart showing an outline of the operation performed by the transmitting side wireless communication device in the embodiment of FIG. 1, and FIG. 3 is a receiving side FIG. 4 is a flowchart showing an outline of the operations performed by the wireless communication device, and FIG. 4 is a diagram showing a sequence during data communication. DESCRIPTION OF SYMBOLS 1... Control part, 2... Communication control part, 3... Modulation/demodulation part, 4... Buffer 7 memory, 5... Radio modulation transmission part, 6... Radio reception and demodulation part, 7. ...Transmission/reception selector switch, 8...Antenna. Figure 1 Figure 4

Claims (1)

[Claims] In a wireless communication device that performs data communication between a pair of wireless communication devices using a predetermined radio frequency, a transmitting side wireless communication device transmits the transmission data to a predetermined frequency before transmitting the transmission data. After dividing data into multiple blocks and transmitting data representing the number of divided blocks, the data of each block is encoded according to a predetermined encoding rule and transmitted continuously up to the final block, and the receiving side The wireless communication device performs error checking on the data received from the transmitting side in block units according to the error checking rule corresponding to the encoding rule, and after receiving the last block of data, the number data of the block in which an error was detected is used as the main data. Requests retransmission by transmitting a block consisting of the number of units of data that has stopped, causes the transmitting side to retransmit the data of the corresponding block, and the wireless communication device on the transmitting side waits for a predetermined period of time after transmitting the last block of data. A wireless communication system characterized in that if a retransmission request is not returned within a certain period of time, only the last block of data is retransmitted to prompt the receiving side to return a retransmission request.