Adaptive multiple access assists multiple users over multiple-input-multiple-output non-orthogonal multiple access wireless networks

Abstract

The works in this study examine three scenarios. The scenario (I) as a common scenario with the base station (BS) and users are equipped with multiple antennae over Nakagami-m fading channels. To improve system performance, the transmit antenna selection (TAS) and maximization of successive interference cancellation (max-SIC) framework are deployed. A novel cumulative distribute function (CDF) for the scenario (I) is proposed, and the outage probability (OP) in novel closed form can be obtained. It is challenging due to scenario (I) consists of massive users equipped with multiple antennae over Nakagami-m fading channels. Therefore, this study proposes scenario (II) with a maximum of SIC and minimum of instantaneous bit rate (max-SIC-min-rate) framework for aiding multiple access to reduce the algorithm complexity of the scenario (I). Some adaptive multiple access strategies are proposed as adaptive PA factors, adaptive min-max bit rate threshold, and adaptive Nakagami-m coefficient are proposed. Finally, the scenario (III) is examined by also applying the max-SIC-min-rate framework as the scenario (II), however, comparing to the adaptive min-max bit rate threshold to investigate the OP, system throughput, and energy-efficient (EE) performances. The obtained results as shown in the numerical results section confirm that, on one hand, the system performance of the scenario (II) is approximate or better than the scenario (I) at the same transmit power; on another hand, the scenario (III) reaches the system throughput and EE performances better than the other scenarios at the high transmit power. The analysis results are proved and verified by Monte Carlo simulation results.