Pattern Design in Joint Space Domain and Power Domain for Novel Multiple Access

Abstract

Abstract-- As a promising radio access technology for future 5G network, novel multiple access (NMA) is aimed to improve spectrum efficiency and access capability via design of successive interference cancellation (SIC) amenable pattern in single domain (e.g. power domain, code domain, and space domain) or joint multiple domains. In this paper, a pattern in joint space and power domain is designed for NMA system. The proposed pattern jointly adopts a quasi-orthogonal space-time block code (Q-OSTBC) in space domain and power allocation (PA) scheme for users in power domain, which is in conjunction with SIC based linear receiver. The pattern utilizes Q-OSTBC with unequal diversity order to mitigate the error propagation in the SIC based detector for each user, and PA for multiple users with different channel gain to improve the spectrum efficiency. Simulation results show that the designed pattern can effectively mitigate error propagation in SIC based system. We also investigate the performance of SIC based receiver with or without channel decoding during the reconstruction of interference, simulation results indicate that the reconstruction with decoding outperform the one without decoding, especially under the condition of low signal-to-noise ratio (SNR). Due to the diversity gain, the NMA system using the designed pattern can obtain higher average sum rate compared to its counterpart, i.e. the combination of Vertical Bell Layered Space-Time code (VBLAST) and PA.