Self-adaptive encoding/decoding method based on low-density parity-check code

Abstract

The invention discloses a self-adaptive encoding / decoding method based on a low-density parity-check (LDPC) code, which comprises the following steps that: according to received data, a receiver performs channel estimation on transmission characteristics of a wireless channel, and performs equalization processing on the received data according to the channel estimation; and an encoding mode of the LDPC code of the data is acquired at the same time. An encoding mode of an LDPC code encoder and the maximum decoding iteration number of the LDPC code of next data transmission are preset according to a channel estimation result and the acquired encoding mode. At a sending terminal, the LDPC code encoder performs the encoding according to the preset encoding mode and sends data after the modulation. At a receiving terminal, the received data is equalized, demodulated, and then performs the decoding of the LDPC code according to the acquired encoding mode and the preset decoding iteration number. The method can improve the utilization rate of channels when the signal-to-noise ratio is lower; and when the signal-to-noise ratio is improved, the method can dynamically reduce the decoding iteration number so as to reduce the operation amount of the decoding.

Description

technical field [0001] The invention relates to the technical field of adaptive channel coding in the communication field, in particular to an adaptive coding and decoding method based on a Low Density Parity Check (LDPC) code. Background technique [0002] In a wireless communication system, due to the existence of noise, fading, and multipath in the transmission channel, distortion and signal judgment errors will inevitably be introduced to the transmitted data. Channel coding technology discovers and corrects signal errors that occur during transmission by adding redundant symbols to the information sequence, thereby improving the reliability of the system. LDPC code is a channel codec method with excellent performance that can approach the Shannon limit. [0003] In a traditional wireless communication system, a fixed channel coding method is adopted, that is, the coding method remains unchanged during the communication process. However, in order to ensure the bit erro...

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Problems solved by technology

[0005] LDPC code decoding adopts an iterative decoding algorithm. The more iterations of decoding, the lower the decoding error rate, but the amount of calculation increases accordingly.

In the adaptive coding system based on LDPC codes, using the current fixed threshold discriminant method to select the coding method produces an unavoidable contradiction

If a larger number of decoding iterations is selected, when the SNR condition is relatively good, it can be switched to a high bit rate coding mode earlier to improve the channel utilization of the system, but it will bring too high a decoding calculation

If you choose a smaller number of decoding iterations, when the signal-to-noise ratio is good, the amount of decoding calculations will be reduced, but at the same time, it will switch to the high-bit-rate encoding mode later, reducing the channel utilization of the system.

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