An Ultra-Reliable Low-Latency Non-Binary Polar Coded SCMA Scheme

The joint transmission scheme of polar codes and sparse code multiple access (SCMA) has been regarded as a promising technology for future wireless communication systems. However, most the existing polar-coded SCMA (PC-SCMA) systems suffer from high latency caused by feedback iteration list decoding. In addition, error performance PC-SCMA is unsatisfactory ultra-reliable transmission. Inspired compelling benefits non-binary codes, in this paper, we design (NB-PC-SCMA) system with free order matching strategy to address issues delay reliability. Specifically, first formulate factor graph NB-PC-SCMA propose successive cancellation (NB-SCL) damping based iterative detection decoding (NSD-JIDD) multiuser receiver improve BER performance. Then, lazy-search NB-SCL (L-NB-SCL) proposed reduce computational complexity simplifying path search pattern decoder. After that, modify update user nodes convergence finally improved NSD-JIDD (ISD-JIDD) algorithm, which can avoid redundant operations exploiting L-NB-SCL Simulation results show that achieves better bit rate (BER) considerable gain when compared its counterparts. particular, ISD-JIDD achieve similar less complexity.