Developing Optimal Spectrum Sharing Protocol and Optimal Linear Precoding for Multi-Carrier Code-Division Multiple Access Using Massive Multiple Input Multiple Output in 5G Wireless Networks

Currently, wireless systems are moving towards implementing fifth-generation (5G) wireless networks to compensate for intense growth and surpass demands concerning future wireless services. Consequently, massive multiple-input multiple-output (mMIMO) and multi-carrier code-division multiple access (MC-CDMA) have received considerable attention for addressing the prevailing constraints in developing 5G mobile networks. To meet requirements related to future wireless services such as achieving elevated data rates, avoiding multi-user co-channel interference (CCI), and satisfying other network limitations, implementing MC-CDMA with mMIMO has become mandatory. In this study, a detailed literature review is conducted on research for implementing MC-CDMA and mMIMO, and it is determined that the utilised methods fail to effectively solve previous issues. Thus, this paper proposes combining an optimal spectrum sharing (OSS) protocol and optimal linear precoding (OLP) with MC-CDMA and mMIMO. The OSS protocol provides an optimal allocation of power with improved quality of service. It is utilised to provide resource allocation with energy efficiency and high spectrum efficiency. Additionally, implementing OLP maximises the system capacity of MC-CDMA-based mMIMO wireless networks. Further, the performance of OLP is improved by introducing the salp swarm algorithm, which helps in finding the optimal precoding vector for the respective system. The proposed methods were employed in MATLAB for analysing system parameters, including the bit error rate (BER), signal-to-noise ratio, and system capacity. Moreover, the proposed work is contrasted with existing methods based on zero-forcing (ZF), regularised ZF (RZF), space–time RZF, minimum mean square error, and a relay precoder.