Multichannel Design of Non Uniform Constellations for Broadcast/Multicast Services

Abstract

Recent studies have shown the potential performance gain of Non Uniform Constellations (NUC) compared to the conventional uniform constellations. NUC can be a promising candidate in 5G systems to increase the data throughput. In the literature, NUC is designed for a specific SNR value and propagation channel. However, in broadcast/multicast services, the received signal by different users will see independent and different channels. Hence, in this paper, we focus on the potential gain of NUC when jointly optimized for more than one propagation channel. In order to assess the gain, we propose an iterative algorithm to jointly optimize the NUC for different channel conditions. The resulting constellations are then compared to uniform constellation and single channel NUC. The simulation results show that the newly designed constellations outperform the classical single channel NUC across different channel conditions when the average performance (across different channels) is considered.Index Terms-5G Physical Layer, Constellations, Nonuniform QAM, broadcast/multicast. I.