|| Capacity Optimality of AMP in Coded Systems
||Lei Liu, Japan Institute of Science and Technology, Japan; Chulong Liang, ZTE Corporation, China; Junjie Ma, Chinese Academy of Sciences, China; Li Ping, City University of Hong Kong, Hong Kong SAR of China|
||D4-S2-T2: Decoding and Optimality
||Thursday, 15 July, 22:20 - 22:40
||Thursday, 15 July, 22:40 - 23:00
This paper studies a large random matrix system (LRMS) model involving an arbitrary signal distribution and forward error control (FEC) coding. We establish an area property based on the approximate message passing (AMP) algorithm. Under the assumption that the state evolution for AMP is correct for the coded system, the achievable rate of AMP is analyzed. We prove that AMP achieves the constrained capacity of the LRMS with an arbitrary signal distribution provided that a matching condition is satisfied. We provide related numerical results of binary signaling using irregular low-density parity-check (LDPC) codes. We show that the optimized codes demonstrate significantly better performance over un-matched ones under AMP. For quadrature phase shift keying (QPSK) modulation, bit error rate (BER) performance within 1 dB from the constrained capacity limit is observed.