Interpretation method and apparatus for tail-biting convolutional code

Abstract

Embodiment of the present invention discloses a decoding method and apparatus for tail-biting convolution code. The method includes the steps of implementing Viterbi decode to a sequence obtained by repeating a transmission block end-to-end for multiple times, wherein after decoding each transmission block of the sequence, judging whether meeting output condition based on a maximum path obtained by the decode; when meeting output condition, outputting decode data of the sequence using the maximum path as backtracking path. In the embodiment of the invention, judging the Viterbi decode of a long sequence obtained by linking a plurality of transmission blocks based on the head end status of the maximum path, when meeting presetting output condition, a decode data can be obtained directly without calculating all transmission blocks, thus it is able to obtain right decode output using less transmission blocks, and computational complexity and decode time delay are all saved.

Description

technical field [0001] The present invention relates to the field of communication technology, in particular to a decoding method and device for a tail-biting convolutional code. Background technique [0002] In the prior art, the encoding and modulation method of the tail-biting convolutional code is proposed, and the tail-biting convolutional code used in the LTE (Long Term Evolution, Long Term Evolution) system is used as an example for illustration. The (3, 1, 6) encoder is as follows: figure 1 shown. [0003] The encoder has a constraint length of 7 and a code rate of 1 / 3. figure 1 Generator polynomial G in i The binary sequence of (i=0, 1, 2) represents the input data and the connection status of the 6 shift registers and the i-th output of the encoder. Binary 0 means not connected, binary 1 means connected. figure 1 The middle adder is performed in the GF(2) field. The initial state of the shift register is the last 6 bits of the input bit sequence, so that η 0 ...

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Problems solved by technology

[0022] In the process of implementing the present invention, the inventor found that the implementation in the prior art has the following problems: the decoding delay and calculation amount of the existing Viterbi decoding algorithm of the tail-biting convolutional code are fixed, even when the channel quality is very low. Well, when there are few errors in the received sequence, it is necessary to calculate L TB blocks before generating the decoding output. In fact, it is possible to obtain the correct decoding output with only a few TB blocks. Therefore, the existing method increases Calculation amount and decoding delay

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