The check-bits-weight-adjustable scheme of rate compatible modulation based on the systematic Polar code

Abstract

Rate compatible modulation is a novel adaptive transmission technology that does not require channel state information feedback, can achieve rate adaptive adjustment, and smoothly approach channel capacity. However, due to the nature of incremental decoding, the decoding complexity is too high and the transmission performance is reduced under bad channel conditions. Based on the feature of the systematic Polar code that separates the information bits and the check bits, this paper optimizes the design of the hybrid cascade of the systematic Polar code and rate-compatible modulation, and proposes a feasible scheme for adjusting the corresponding weight of check bits. The simulation results show that the proposed scheme can achieve better transmission performance in a wider range of signal-to-noise ratio with relatively lower decoding overhead.