Decoding algorithms for binary LDPC coded Gaussian interference channels

This paper is concerned with Gaussian interference channels (GIFC) in which all transmitters are coded with binary low-density parity-check (LDPC) codes. We focus on the design of decoding algorithms. The main contributions of this paper include: 1) we present three types of iterative decoding algorithms (IDA), which are computing-decoding type, decoding computing type and computing-decoding-computing type, respectively; 2) we propose a joint decoding algorithm (JDA) by treating the system as a nonbinary LDPC (NB-LDPC) coded system; 3) we propose a time-varying signaling scheme for the joint decoding algorithm. Numerical results show that, 1) for weak interference, the four decoding algorithms have almost the same error performances, 2) for moderate and strong interference, the JDA has the best error performance. These results show that structures in interference can be utilized to achieve better performances. In addition, it is shown by simulation that, from moderate to strong interference, the time-varying signaling scheme significantly outperforms the constant signaling scheme when decoded with the JDA (8.5 dB for strong interference).