SU684762A1 - Cascade code combination receiver - Google Patents

Description

The invention relates to communications, may be used in discrete information transfer systems. A known receiver of cascade code combinations comprising a first decoder serially connected, a code symbol accumulator, a decision block and a second decoder, the second output of the first decoder through the accumulator being connected to the second input of the decisive block 1. However, the known receiver is not sufficiently accurate in receiving information iterative coding. The purpose of the invention is to increase the loyalty of the method. To do this, the receiver of cascade code combinations containing the serially connected first decoder, the code accumulator of the code, the decision block and the second decoder, the second output of the first decoder being connected to the second input of the decision block through the accumulator, the series-connected threshold block, a counter .. numbers erasers and sensor signals, the output of which is connected to the input of the drive. The drawing shows a structural electrical circuit of the proposed receiver. The receiver contains a threshold unit 1, a first decoder 2, a drive of 3 code symbols, a decision block 4, a second decoder 5, a counter 6 of the number of erasures, a sensor 7 of signals, and a drive 8. The receiver works in a trace way. The threshold unit 1, depending on the reception conditions of the signal from the continuous communication channel, decides on the value of the received symbol and, if the signal parameters do not match the set values, produces an erase signal. The input of this unit is the information input of the receiver. One output of the threshold block is connected to the input of the decoder 2, and the other is connected to the input of the counter 6, having erased it. Counter 6 counts the number of erasures recorded on the length of one subblock, and outputs this result to the sensor 7 cut bars, where the value specified for the first one used

steps value d | is divided by the value of Sj obtained from counter 6, where d is the value of the minimum code distance of the code, Si is the number of erasures recorded in the code combination. The result of the division is stored in accumulator 8, the input of which is connected to the output of sensor 7.

The decoder corrects erase speeds up to di-1 and causes errors in the sub-blocks in the absence of erasers. To fix the corresponding value of F, where F is the reliability estimate, in the absence of erasures, one output is output, the turn of decoder 2 is connected to the input of accumulator 8. Another decoder is connected to drive 3 characters of the code. The accumulator contains code symbols of the combination of the length of the code of the second stage, obtained as a result of their decoding at the first stage of information processing.

When the accumulator 8 and the accumulator of 3 characters of the code code are fully populated, information from these drives is written in parallel to decisive block 4.

Decision unit 4 selects the most reliable code symbols of the second stage and transmits exactly Ka to the decoder 5 or the set other appropriate value, but always a constant number of characters.

Decoder 5 to K characters. implements the P2-Kj erasure correction. The decoding result is output to the system.

The advantage of such a construction of a receiver of cascade code combinations is a simpler procedure for obtaining the reliability estimates of the second-stage code symbols, the possibility of using discrete information in unidirectional transmission systems, information received from an uninterrupted communication channel, in order to increase the overall system efficiency.

Claims (1)

1. V. V. Zblov and L. F. Zhigulin, Improving the Exponent of the Probability of Error in a Feedback System Using a Cascade Code. The collection Increase of fidelity of transfer of digital information on discrete channels, M., Nauka, 1974, p. 56-62.