System Imperfections on the Overall Performance of MC-CDMA-Based Cognitive Radio Network (CRN) System

Abstract

Cognitive radio network (CRN) is considered to be the future technology for the fifth generation of cellular wireless standards (5G). CRN is based on a complex spectrum allocation system, and licensed primary users (PUs) or unlicensed secondary users (SUs) are allowed to share the spectrum, provided that they do not cause significant interference. In cognitive radio, it is important to control the transmission power of SUs so that the interference should not be harmful to the quality of service of PUs. In this paper, the authors addressed the impact of system imperfections on the overall performance of multi-carrier code division multiple access (MC-CDMA)-based CRN system. A new expression of the signal-to-interference-noise ratio (SINR) for MC-CDMA-based CRN system over a Rayleigh fading channel without any power control condition among the PUs and SUs is derived and investigated. The performance of MC-CDMA-based CRN system over the frequency selective multi-path fading channel is examined by varying the number of users, the signal-to-noise-ratio (SNR) per bit, number of fading path and number of subcarriers, respectively. From the simulation results, we have seen that the SINR performance is affected by these parameters. The analysis presented in this paper shows the impact of lack of a controlling mechanism on transmitted signal power affecting the between PUs and SUs ultimately system performance. The result of the analysis will provide relevant information to design the physical layer protocol for high speed CRN system for 5G.