Punctured Turbo-Polar Codes

Abstract

In this paper, a punctured turbo-polar code (PTPC) is proposed to obtain compatible code rate and flexible code length. Two sets of parity bits are punctured respectively in the encoder. We fill zeros in the puncturing location before sending the code word's log likelihood ratio (LLR) to the iterative decoder. The soft cancellation decoder (SCAN) is used as the soft-input soft-output (SISO) decoder in the iterative decoder for it can provide the lowest complexity and good performance. The simulation results show that the PTPC has the same bit error rate (BER) comparing with the original turbo-polar code when their payload bits are set the same. Moreover, the asymmetric puncturing structure is more beneficial to avoid error propagation in the PTPC's iterative decoding by putting more parity bits in the first parity branch. Therefore, the PTPC can be used to transport information with higher code rate but without performance decreasing and complexity increasing.