PERFORMANCE ANALYSIS OF A mmWAVE-NOMA NETWORK FOR REAL-TIME IoT APPLIC ATIONS

Abstract

The fifth-generation (5G) cellular network is expected to meet the demand for ultra-high data rate, low latency and bulk connectivity due to the massive deployment of internet of things (IoT) sensors and devices. The existing orthogonal multiple access (OMA) techniques fall short to achieve these demands. Thus, 5G comes with some unique exciting features to entertain this gigantic conn ectivity and low latency network. Non-orthogonal multiple access (NOMA) has b een acknowledged as a promising feature to significantly enhance the network capacity. Moreover, 5G offers an extension to the current bandwidth (sub 6 GHz) by enabling millimetre-wave (mmWave) communication. This unutilized mmWave high-frequency band s (30-300 GHz) can carry huge data with an increased bandwidth which paves the way for massive multiple-input multiple-output (Massive MIMO) which facilitates high spectral efficiency (SE) and lowers path loss of mmWave transmission. But this gives rise to the p ower-hungry rad io frequency chain which, in turn, increases the energy consumption with an increased receiver complexity. An energy efficient b eamforming technique is, therefore, vital for an efficient network with high SE. Interference mitigation is another prime concern for better performance in 5G network. The existing interference mitigation techniques for OMA are not fully compatible for NOMA network. Thus, a proper interference mitigation technique is essential to increase the sum rate of the network. In this thesis, a mmWave-MIMO-NOMA system model is presented which provides better the sum rate than some existing counterp art. To deal with the energy consumption, an energy-efficient massive MIMO network with a fuzzy logic switching-based hybrid beamforming (FeE-HBS) is presented. To mitigate the intra-cell interference created by the non-orthogonal users of NOMA, successive interference cancellation (SIC) is applied in the NOMA receivers. A modified fractional frequency reuse (FFR) technique is proposed to avoid inter-cell interference (ICI) which provides lesser bandwidth splitting than the conventional techniques. This lower splitting enables huge no des to accumulate p er sectors of a cell with reduced interference. Thus it improves the network performance while ensuring minimu m ICI. This work develops a mmWave-MIMO-N OMA network with better system capacity. The FeE-HBS system enables lower number of power-hungry phase shifters when the requirement is less. This makes the system more energy efficient with almost the same SE as the conventional digital beamforming design. Lastly, interference mitigation is achieved by implementing SIC and a novel sectored FFR. This novel FFR technique ensures lower interference at a better system throughput than other existing techniques.