Encoding and decoding method, system and device for concatenated spinal codes

Abstract

The present invention relates to a cascaded Spinal code coding and decoding method, system and device. The method comprises the steps of: the step S1: employing a LDPC outer code with a high bit rateby a sending terminal to perform pre-coding of information source bits to generate LDPC middle bits, wherein the LDPC middle bits are subjected to inverted order and processed by a Spinal coder to obtain Spinal codewords, and the Spinal codewords are sent to a wireless channel; and the step S2: receiving a certain amount of Spinal codewords by a receiving terminal from a wireless channel to perform soft decoding, wherein the soft decoding method comprises the steps of: retaining a plurality of survival paths, and calculating the log-likelihood ratio (LLR) of each LDPC middle bit according to the survival paths; and the step S3: performing decoding of the LLR of the LLR of the input LDPC middle bits by the LDPC decoder to obtain decoded information source bits. Compared to the prior art, the LDPC is used by the sending terminal to perform pre-coding of the information source, and the Spinal soft decoder is provided at the receiving terminal to retain the soft information of the LDPC middle bits so as to solve the defects that the protection for the information source bits at the rear position in the information source sequence by the Spinal codes is not enough and obviously reduce the BER of the information source after decoding.

Description

technical field [0001] The present invention relates to an encoding and decoding algorithm, in particular to an encoding and decoding method, system and device for concatenated Spinal codes. Background technique [0002] Due to the time-varying characteristics of fading, noise and interference in wireless channels, how to effectively counteract these unstable factors and maximize the data transmission rate is a hot spot and key point in wireless communication research. Link adaptation is the key technology to solve this problem. The physical layer using link adaptive technology automatically selects the appropriate transmission rate to match the time-varying channel. Traditional link adaptation technologies mainly include Adaptive Coding and Modulation (AMC) and Hybrid Automatic Repeater (HARQ). In these two technologies, the receiving end estimates the channel condition according to the pilot signal, then parameterizes the channel condition, and feeds back these parameter...

AI Technical Summary

Problems solved by technology

However, this traditional link adaptation scheme has two problems that have not been solved for a long time: one is that it is difficult to always obtain accurate channel condition estimates because the channel changes faster than the sending rate of a single packet in a very short period of time ; Second, the sending rate of the sending end can only be adjusted in a stepwise manner, which does not make full use of the channel capacity

However, due to the structural characteristics of the Spinal code, the protection of the source is not equal.

In a frame of source bits, the Spinal code has strong protection for the source bits in the front position, but weak protection for the source bits in the back position. The better throughput performance of the existing Spinal code depends largely on CRC checksum, in the scenario without CRC checksum, the throughput and BER of Spinal code are not ideal.

In many real-time transmission scenarios (such as video transmission), the Spinal code cannot be retransmitted without limit until all sources can be transmitted without errors, that is, the CRC checksum cannot be used

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