Performance analysis of non orthogonal multiple access scheme for future wireless communication systems

Abstract

Future wireless communication networks require massive connectivity and high data rates with a latency of one millisecond. Recently, Non-orthogonal multiple access (NOMA) was introduced to meet these challenges which provide high throughput and high spectral efficiency. In this thesis, we focus on power domain-NOMA in the downlink scenario where the base station (BS) transmits the data using superposition coding and user equipment (UE) applies the successive interference cancellation (SIC) to recover desired signals. newlineTo meet the required challenges, NOMA has ample of radio resources for providing the quality of service. Due to the increase in radio resources, the performance is limited by considerable interference and lack of perfect channel state information (CSI) at the transmitter. The error in the channel estimation and power of the required as well as interfering signal may affect the outage performance of NOMA. To address these issues, in this work we presented an approach to derive the expressions of outage probability for NOMA-based communication system. In this work, the closed-form expressions of outage probability are obtained for Nakagami-m and Rayleigh faded channels with and without shadowing, Rician fading, and#954;-µ shadowed faded, and#945;-µ, and#951;-µ and and#945;-and#951;-µ faded channels. The outage expressions are derived with channel estimation error, intra, and inter-cell interference. The outage results are evaluated for two user NOMA such as near and edge positions of a cell. The impact of channel estimation error and inter-cell interference is analysed for both users. newlineSo far, the performance of NOMA is analyzed in common fading channels like Rayleigh, Rician and Nakagami-m. The exact outage probability of NOMA over and#954;-µ shadowed faded channel, considering inter-cell and intra-cell interference and noise newlineis not addressed in the literature. In this work, a simple and illustrative approach is presented to evaluate the outage probability expressions of NOMA for maximum ratio and selection combining approaches.