基于变长Turbo码的低复杂度联合信源信道译码

Low-complexity joint source-channel decoding based on variable length encoded Turbo codes

基于变长Turbo码的联合信源信道译码通过构造联合译码平面网格图,具有比比特级译码更好的性能.但平面网格图复杂,使变长Turbo码译码复杂度高.基于此,构造了一个空间网格图,提出基于变长Turbo码的低复杂度联合信源信道译码方法.仿真结果表明,该算法比平面网格图计算复杂度减少约3.8%,在SER(symbol error ratio)为10-4时,获得Eb/N0增益约为0.2dB.

Variable length encoded Turbo codes（VL Turbo codes） with constructed joint decoding plane trellis has better decoding performance than the bit-level decoding algorithm.However the plane trellis is complicated,resulting in a high decoding complexity of VL Turbo codes.We construct a space trellis and propose a low-complexity JSCD approach based on VL Turbo codes.Simulation results show that the proposed approach reduces the decoding complexity by 3.8%,compared to the plane trellis,and the gain of Eb /N0 is about 0.2dB at SER = 10-4.