Polarization code iteration construction method based on path metric difference

The invention discloses a path metric difference-based polarization code iterative construction method, which comprises the following steps of: determining an initial structure, and generating an initial message sequence according to the initial structure; performing Polar coding, modulation and noise addition on the initial message sequence; carrying out demodulation and SCL decoding on the noised message sequence; calculating a path metric difference value and a log-likelihood ratio based on an SCL decoding result; finding out frozen bits according to the path metric difference and the log-likelihood ratio so as to update the initial structure; calculating a current code rate according to the updated initial structure, judging whether the current code rate reaches a target code rate or not, if so, taking the updated initial structure as a target structure, generating a target message list according to the target structure, and performing Polar coding and SCL decoding processes on a target message sequence,