JP2002077116A - Error control system in wireless data transmission - Google Patents

Abstract

PROBLEM TO BE SOLVED: To solve a problem of preventing wireless data transmission from deteriorating in transmission efficiency due to the fact that all frame data must be resent if even a signal error is found in the received frame data. SOLUTION: A data frame which has undergone error detection, error correction encoding, and bit interleave processing is divided into a prescribed number of blocks, and the blocks of data frame are stored in a block data split storage 6. A receiving end splits the received frame data as well as the block data split storage 6 and stored in a-block data storage synthesizer 16. When errors are detected after the frame data has been subjected to bit interleave processing and corrected for errors, an error pattern is estimated by an error system estimator 18, a block where errors occur is discriminated from others by a resending block discriminator 20, and a request to resend the data block is made. A sending end receiving the request to resend the data block extracts the designated data block from the block data split storage 6 to resend it to a receiving end.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an error control system in wireless data transmission, and more particularly to an error control system having excellent transmission efficiency.

[0002]

2. Description of the Related Art FIG. 3 is a schematic diagram showing an example of an error control system in a conventional wireless data transmission system for mobile communication. As shown in the figure, the transmitting apparatus of this system includes a data division unit 1, a data storage unit 2, an error detection encoding unit 3, an error correction encoding unit 4, a bit interleave unit 5, a multiplexing unit 7, It comprises a unit 8, a transmitting unit 9 and an antenna 10. Further, the receiving side device includes an antenna 11, a receiving unit 12, a demodulating unit 13, a separating unit 14, a bit deinterleaving unit 15, an error correcting unit 17, an error detecting unit 19, a data combining unit 21, and a data storing unit 22. You.

In FIG. 3, when transmission data is input to a data division unit 1, the data is divided into blocks based on the frame format of the radio system and stored in a data storage unit 2, and error detection is performed in accordance with a frame output timing. It is output to the encoding unit 3 and an error detection code is added. Further, the error correction code is added by the error correction coding unit 4, and input to the bit interleave unit 5. The bit interleaving unit 5 performs a bit interleaving process for converting a burst error generated by fading or the like in a transmission path between transmission and reception into a random error, and multiplexes control data such as a synchronization word in a multiplexing unit 7. The signal is converted into an analog signal by the modulator 8 and transmitted from the transmitter 9 via the antenna 10.

The transmitted radio wave is received by a receiving unit 12 via an antenna 11, converted into a digital signal by a demodulation unit 13, and separated into a control signal such as a synchronization word and a data signal by a separation unit 14. You. The data signal output from the demultiplexing unit 14 is subjected to bit deinterleaving by a bit deinterleaving unit 15, then error correction is performed by an error correction unit 17, and error detection is performed by an error detection unit 19. If no error is detected in the data by the error detection unit 19, the data is stored in the data storage unit 22. When all the divided data are input, the data synthesis unit 21 synthesizes the data. Output as received data. If an error is detected in the data in the error detecting section 19, a retransmission request signal requesting that the frame data be transmitted again is sent to the error detecting section 1.
9 and transmitted to the transmitting side by a separately prepared transmitting device (not shown). In response to the retransmission request signal, the transmitting side transmits the corresponding frame data again. Then, the above operation is repeated until the receiving side can receive the frame data without error.

[0005]

However, according to the above-described error control method, when an error is detected in the data within a frame in the error detecting section, the entire data of the frame must be retransmitted. become,
There was a problem that transmission efficiency was poor. The present invention has been made to solve the above-described problem, and has as its object to provide an efficient error control method in a wireless data transmission system.

[0006]

In order to solve the above-mentioned problems, in an error control system for wireless data transmission according to the present invention, transmission for transmitting frame data subjected to error detection coding and error correction coding and bit interleave processing is performed. Means for transmitting and receiving the data transmitted from the transmitting means, and performing a bit deinterleaving process on the received data by receiving the data transmitted from the transmitting means. A receiving-side divided storage means for dividing and storing the received data beforehand in the same manner as the transmitting-side divided storage means; and an error correction and error detection for the bit-deinterleaved received data, and an error is detected when the data is detected. Convolutionally encodes the data after the correction processing, and compares the convolutionally encoded data with the bit deinterleaved data. Receiving-side equipment comprising: an error-sequence estimating means for estimating an error sequence by using a retransmission-block determining means for determining a block containing an error equal to or more than a predetermined value based on an output of the error-sequence estimating means and requesting a transmitting side to retransmit. In response to a retransmission request from the retransmission block determining unit, the transmitting side extracts a specified data block from the data blocks divided and stored in the transmitting side divided storage unit and transmits the extracted data block to the receiving side. The receiving side replaces the received retransmitted data block with the data block divided and stored in the receiving side divided storage means, outputs the received data block as received data, and performs bit interleave processing.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described in detail based on an embodiment shown in the drawings. FIG. 1 is a schematic diagram showing an example of an embodiment of an error control method in a wireless data transmission system according to the present invention. As shown in FIG. 1, the transmitting side apparatus of this system includes a data division unit 1, a data storage unit 2, an error detection encoding unit 3, an error correction encoding unit 4, a bit interleave unit 5, a block data division storage unit. 6, multiplexing unit 7, modulating unit 8, transmitting unit 9 and antenna 10
It consists of. Further, the receiving side device includes an antenna 11, a receiving unit 12, a demodulating unit 13, a separating unit 14, a bit deinterleaving unit 15, a block data storing and combining unit 16, an error correcting unit 17, an error sequence estimating unit 18, and an error detecting unit 19. , A retransmission block determination unit 20, a data synthesis unit 21, and a data storage unit 22. The functional operation of each component of the error control system according to the present invention is as follows: the bit interleave unit 5 and the block data division storage unit 6 on the transmission side; the bit deinterleave unit 15 and the block data storage / synthesis unit 16 on the reception side; Since the functional operations are the same as those of the components having the same numbers in FIG. 3 except for the error sequence estimating unit 18, the error detecting unit 19, and the retransmission block determining unit 20, detailed description of the operations of the common units is omitted I do.

In FIG. 1, transmission data divided into blocks based on the frame format of the system by a data division unit 1 and stored in a data storage unit 2 is added with an error detection code by an error detection encoding unit 3, Further, the error correction code is added to the error correction code by the error correction coding unit 4 and the result is input to the bit interleave unit 5. The bit interleave unit 5 performs a bit interleave process for converting a burst error generated due to fading or the like in a transmission path between transmission and reception into a random error. The bit-interleaved data is output to the multiplexing unit 7 and divided into a predetermined number of blocks and stored in the block data division storage unit 6. In the multiplexing unit 7, control data such as a synchronization word is multiplexed, further converted into an analog signal by the modulation unit 8, and transmitted from the transmission unit 9 via the antenna 10.

The transmitted radio wave is received by a receiving unit 12 via an antenna 11, converted into a digital signal by a demodulating unit 13, and separated into a control signal such as a synchronization word and a data signal by a separating unit 14. You. This data signal is supplied to the bit deinterleave unit 15 and the block data storage / synthesis unit 1
7, and in the data storage / combination unit 14,
As data before bit deinterleaving, the data is divided into blocks similar to the block data division storage unit 6 on the transmission side and stored. On the other hand, the bit deinterleave unit 15
Are output to the error correction circuit 17 after being subjected to bit deinterleave processing. The error correction unit 17 performs data error correction processing, and the error detection unit 19 performs error detection processing. If no error is detected, the data is stored in the data storage unit 22, and when all the frame data are input to the data storage unit 22, the data synthesis unit 21 synthesizes the data and the received data is received. Is output as

When an error is detected in the data by the error detecting section 19, an error pattern estimating section 18 estimates an error pattern and a retransmission block determining section 20 as described later.
, A block containing an error is determined, and a retransmission request signal requesting retransmission of the data block is generated. This retransmission request signal is sent to the transmitting side by a separately prepared transmitting device (not shown). Upon receiving the request signal, the transmitting side extracts a data block designated to be retransmitted from the block data division storage section 6 and retransmits it to the receiving side via the multiplexing section 7, the modulation section 8, and the transmission section 9. On the receiving side receiving the retransmitted data block, the retransmitted data block and the retransmitted data block among the data blocks stored in the block data storage / synthesis unit 16 are exchanged and stored. When the data is completed, the data is read from the head and output to the bit deinterleave unit 13. This data is subjected to a bit deinterleave process and an error correction process as described above, and if no error is detected by the error detection unit 19, the data storage unit 22
When the data is stored and all the frame data are prepared, the data is output from the data synthesizing unit 21 as received data. When the error detecting unit 19 detects an error again, the procedure of transmitting a retransmission request signal is repeated in the same manner as described above. This operation is repeated a predetermined number of times. If an error is still detected, a signal requesting retransmission of all frame data is transmitted to the transmitting side, and data transmission is performed again.

FIG. 2A shows the error sequence estimator 18.
FIG. 2B shows the retransmission block determination unit 20.
FIG. 2 is a schematic diagram showing an example of each of the configurations. The error sequence estimator 18 includes a convolution encoder 18a and a data comparator 18a.
b, and the retransmission block determination unit 20 includes a bit interleave unit 20a, a block division unit 20b, and a threshold comparison unit 20c. FIG. 2 (a)
As shown in (2), when an error is detected in the data by the error detection unit 19, the decoded data corrected by the error correction unit 17 is input to the convolutional coding unit 18a of the error sequence estimation unit 18, Code data that would have been transmitted is output from the convolutional encoder 18a. The output and the data deinterleaved by the bit deinterleaver 15 are compared by a data comparator 18b. The error of the data bit is estimated as described above, and the result is output to the bit deinterleave circuit 20a of the retransmission block determination unit 20.

As shown in FIG. 2B, the error estimation data output from the error sequence estimator 18 is supplied to a bit interleave circuit 20 a of a retransmission block determiner 20.
After being rearranged into a format similar to the data format of the output of the bit interleave unit 5 on the transmission side, the block division unit 20b divides the data into blocks similar to the data stored in the block data division storage unit 6 on the transmission side. You. The error estimation data divided into the blocks is output to the threshold value comparison unit 20c, and a predetermined threshold set based on the number of error estimation data included in each block, the frame length, the type of the correction code, and the like. The threshold value is compared with the threshold value. If the error estimation data number is larger than the threshold value, a retransmission request for the block data is output. As described above, when an error is detected, the amount of data retransmitted from the transmitting side in response to a retransmission request is limited to only a block including a relatively serious error among blocks obtained by dividing one frame of data. Since it is good, the transmission efficiency is improved.

[0013]

As described above, according to the present invention,
By dividing the frame data into blocks and retransmitting only those blocks that may contain relatively serious errors, transmission error control is extremely efficient compared to the conventional method of retransmitting the entire frame. Can be realized.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram showing an example of an embodiment of an error control method of a wireless data transmission system according to the present invention.

FIG. 2A is a diagram illustrating an example of an error sequence estimation unit 18 shown in FIG.
2B is a schematic configuration diagram illustrating an example of each of the retransmission block determination units 20 in FIG. 1.

FIG. 3 is a schematic configuration diagram showing an example of an error control method of a conventional wireless data transmission system.

[Explanation of symbols]

1. Data division unit 2. Data storage unit 3.
An error detection encoder, an error correction encoder,
5 bit interleave section, 6 block data division storage section, 7 multiplex section, 8 modulation section, 9 transmission section, 10, 11 antenna,
12 receiving section, 13 demodulating section, 14 separating section, 15 bit deinterleaving section, 16
Block data storage / synthesis unit, 17 error correction unit, 18 error sequence estimation unit,
18a: convolutional code section, 18b: data comparison section, 19: error detection section, 2
0 ··· Retransmission block determination unit, 20a ··· bit interleave circuit, 20b ··· block division unit,
20c threshold comparator, 21 data synthesizer, 22 data storage

Claims (1)

[Claims] 1. A transmitting means for transmitting frame data subjected to error detection coding and error correction coding and bit interleaving processing, and a transmitting side divided storage means for dividing the frame data into a predetermined number of blocks and storing the divided data. Transmitting side equipment having, receiving side divided storage means for receiving data transmitted from the transmitting means, and dividing and storing the received data in the same manner as the transmitting side divided storage means before bit deinterleaving processing, When error is detected in the data by performing error correction and error detection on the deinterleaved received data, the data after the error correction processing is convolutionally encoded, and the convolutionally encoded data and the bit deinterleave processing are performed. Error sequence estimating means for estimating an error sequence by comparing the data with the error data; A retransmission block determining unit that determines a block to be retransmitted and requests a retransmission to the transmitting side, and in response to a retransmission request from the retransmission block determining unit, the transmitting side stores the transmission side divided storage. The specified data block is extracted from the data blocks divided and stored in the means, and the extracted data block is transmitted to the receiving side, and the receiving side splits and stores the received retransmitted data block in the receiving side divided storage means with the data block. An error control method in wireless data transmission, wherein the data is output as received data after being exchanged, and bit interleaving processing is performed.