所属单位：北京航空航天大学

教研室：未来通信与网络推进组 202/203教研室

发表刊物：IEEE 信号处理杂志

刊物所在地：美国

项目来源：国家重点研发 6G 《灵活高效波形与多址》 No.2020YFB1807102

关键字：编码调制、格码、计算与传递、多址、污纸编码

摘要：Structured codes based on lattices were shown to provide enlarged capacity for multi-user communication networks. In this paper, we study capacity-approaching irregular repeat accumulate (IRA) codes over integer rings Z_{2^m} for 2^m-PAM signaling, m = 1,2,.. . Such codes feature the structural property that the integer sum of K codewords belongs to the extended codebook (or lattice) w.r.t. the base code. With it, the gains promised in lattice based network information theory can be materialized in practical systems with 2m-PAM signaling. In designing IRA ring codes, we first analyze the effect of zero-divisors of integer ring on the iterative belief-propagation (BP) decoding, and show the invalidity of symmetric Gaussian approximation. Then we propose a doubly IRA (D-IRA) ring code structure, consisting of irregular multiplier distribution and irregular node-degree distribution, that can restore the symmetry and optimize the BP decoding threshold. For point-to-point AWGN channel with 2m-PAM inputs, D-IRA ring codes perform as low as 0.29 dB to the capacity limits, outperforming existing bit-interleaved coded-modulation (BICM) and IRA modulation codes over GF(2m). We then proceed to design D-IRA ring codes for two important multi-user communication setups, namely dirty paper coding (DPC) and compute-forward (CF). With it, a simple linear DPC scheme exhibits a gap to the capacity by 0.91 dB, and a physical-layer network coding scheme yields a gap to the CF limit by 0.24 dB.

论文类型：期刊论文

一级学科：信息与通信工程

文献类型：期刊

是否译文：否

发表时间：2022-09-29

收录刊物：SCI