Performance Evaluation of Beamspace(BS) Multiple Input Multiple Output(MIMO) NOMA System to Enhance Spectral Efficiency of 5G Wireless Networks

Abstract

Future requirements for wireless and cellular communication in the present and the follow ing ten years call for the support of a wide range of services, including system average throughput, the explosion of mobile traffic, live HD streaming, improved location-based ser vices (LBS), M2M communication, cloud computing, etc. These provide numerous difficul ties in terms of spectrum efficiency, data flow, capacity, and coverage. As a result, there will be a significant amount of traffic demand in the down-link direction, and future genera tions of wireless networks are expected to ensure excellent quality of service (QoS) and offer ubiquitous services for multiple users. The millimeter wave (mmWave) communications in troduced to achieve the rapidly growing network capacity requirements for next-generation wireless systems. In millimeter-wave (mmWave) large MIMO systems, the recently developed beamspace multiple input multiple output (BS-MIMO) idea can greatly reduce the number of radio-frequency (RF) chains necessary without obviously compromising performance. How ever, The main limitation of existing BS MIMO is that the number of supported users cannot be more than the number of RF chains using the same time-frequency resources. In this thesis, we provide a novel, spectrum-efficient mmWave transmission method that combines BS-MIMO and the idea of non-orthogonal multiple access (NOMA) in order to overcome this basic restriction. By employing NOMA, BS-MIMO systems may accommodate more users than the number of RF chains using the same time-frequency resources. An obvious perfor mance boost over the existing BS-MIMO is shown when the suggested BS-MIMO NOMA is compared to its potential achievable sum rate in a typical mmWave channel model. Follow ing that, a precoding strategy based on the zero-forcing (ZF) concept is created to minimize inter-beam interferences in the BS-MIMO-NOMA system. Finally, an iterative optimization algorithm with low complexity is developed to realize the dynamic power allocation.The simulation’s results show that compared to the already in use BS-MIMO OMA, the proposed BS-MIMO-NOMA may achieve a higher spectrum efficiency.