Multiple Input Multiple Output Non-Orthogonal Multiple Access for 5G Cellular Networks

Abstract

The increasing demands for high throughput in the 5G are posing different challenges for the design of access schemes. To meet these challenges, new multiple access (MA) schemes are being developed. Non-orthogonal multiple access (NOMA) is considered as one of the outperformance multiple access technique to deal with the heterogeneous wireless networks. Broadly, NOMA is classified as power-domain and code-domain NOMA. In power-domain, NOMA can serve multiple users with the same time, frequency and code but using different power levels. This feature make NOMA capable of increasing spectral efficiency gain over the conventional multiple access schemes. In this thesis, a comprehensive analysis about power domain NOMA for future cellular systems is performed. The entire analysis is done by targeting Quality of Service (QoS) of NOMA users. The whole work is split into two major sections; Single-input Single-output (SISO) NOMA and Multiple-input Multiple-output (MIMO) NOMA. The thesis provides an in-depth analysis of downlink power domain NOMA under various fading channels, modulation schemes and channel code rates. In SISO NOMA, power domain multiplexing with superposition coding is done at the transmitter side and practical successive interference cancellation (SIC) with zero forcing (ZF) is used at the receiver side. Performance of MIMO NOMA is analyzed by using Orthogonal Space Time Block Coding (OSTBC) with power multiplexing at the transmitter side and low complexity Maximum Likelihood (ML) detector at the receiver side. The thesis provides a good foundation for the development of Adaptive Modulation & Coding (AMC) schemes for future NOMA-based 5G systems.