Generalized Segmented Bit-Flipping Scheme for Successive Cancellation Decoding of Polar Codes With Cyclic Redundancy Check

As a new flavor for the successive cancellation decoding of polar codes, bit-flipping technology can be used to improve the frame error rate performance of polar codes at moderate code lengths. In this paper, a generalized segmented scheme of bit-flipping technology is taken into full consideration, in which several segmented decoding patterns are described. First, the basic ones considering single-error-correcting and multiple-error-correcting are described, where a fully protected CRC is used. Second, with a constructed critical set for the segmented scheme, the improved version of the above basic patterns is fully discussed. Unfrozen bits corresponding to the critical set called critical information bits are divided into several parts and protected by cyclic redundancy check codes. Third, for a better performance of the segmented scheme, a segmented strategy indicating the positions of segments is effectively designed by analyzing the effect of positions of cyclic redundancy check and the error probability of each bit. At last, the frame error rate performance and the average computational complexity of the segmented decoding patterns are analyzed at matching average computational complexity or under equivalent frame error rate for different rates of polar codes. By proper design, the simulation results in additive white Gaussian noise channel demonstrated that the segmented decoding patterns can efficiently improve the error-correction performance of the flip-based scheme at different rates of polar codes while keeping a lower complexity.