Judgement of error frames using frozen bits and its applications in decoding of polar codes

Abstract

AbstractPolar codes have received widespread attention because of their excellent performance. However, although successive cancellation (SC)‐based decoding algorithms have achieved excellent error correction performance, they still encounter large time delays in decoding because a serial decoding structure is employed. At present, a cyclic redundancy check (CRC) is used to judge whether the decoding result of a frame is erroneous. To obtain such a result, the decoder has to wait until the end of decoding. In this work, a judgement strategy for error frames using frozen bits is proposed. With the proposed strategy, the recognition of erroneously decoded frames can be achieved based on the error state of the frozen bits in this frame. Accordingly, early termination of decoding can be realized. By using this mechanism, the strategy can also be applied in the SC List algorithm to prune the path. In addition, the SC Flip decoding algorithm can also use the proposed strategy to help find the first error message bit. The experimental results show that at least 85% of the frames decoded erroneously can be recognized by the proposed strategy so that decoding can be terminated in advance and computational resources can be saved.