Resource Allocation for Throughput Maximization in Cognitive Radio Network with NOMA

Xiaoli He,Xinwen Cheng,Weijian Yang,Muhammad Owais,Yu Song,Yu Xue

doi:10.32604/cmc.2022.017105

Abstract

Spectrum resources are the precious and limited natural resources. In order to improve the utilization of spectrum resources and maximize the network throughput, this paper studies the resource allocation of the downlink cognitive radio network with non-orthogonal multiple access (CRN-NOMA). NOMA, as the key technology of the fifth-generation communication (5G), can effectively increase the capacity of 5G networks. The optimization problem proposed in this paper aims to maximize the number of secondary users (SUs) accessing the system and the total throughput in the CRN-NOMA. Under the constraints of total power, minimum rate, interference and SINR, CRN-NOMA throughput is maximized by allocating optimal transmission power. First, for the situation of multiple sub-users, an adaptive optimization method is proposed to reduce the complexity of the optimization solution. Secondly, for the optimization problem of nonlinear programming, a maximization throughput optimization algorithm based on Chebyshev and convex (MTCC) for CRN-NOMA is proposed, which converts multi-objective optimization problem into single-objective optimization problem to solve. At the same time, the convergence and time complexity of the algorithm are verified. Theoretical analysis and simulation results show that the algorithm can effectively improve the system throughput. In terms of interference and throughput, the performance of the sub-optimal solution is better than that of orthogonal-frequency-division-multiple-access (OFDMA). This paper provides important insights for the research and application of NOMA in future communications.

Highlights

The secondary users (SUs) of the cognitive radio network (CRN) can have an opportunity to access the licensed spectrum of the primary user (PU)
We propose a maximum throughput algorithm for CRN-Non-orthogonal multiple access (NOMA) based on Chebyshev and Convex optimization, which specific steps are shown in Algorithm 1
The simulation assumes that the network coverage is 150 and 150 m, where primary base station (PBS), secondary base station (SBS), PU and SUs are randomly distributed in the network

Summary

Introduction

The secondary users (SUs) of the cognitive radio network (CRN) can have an opportunity to access the licensed spectrum of the primary user (PU). Spectrum utilization can be improved by sharing spectrum between SUs and PU. The researches about CRN mainly focus on the network resources allocation. The flexibility of radio spectrum access brings new challenges to CRN. How to use the limited spectrum resources to provide higher transmission rates for more users has always been a focus and research issue in the wireless communication field. Compared with orthogonal multiple access (OMA), NOMA can allocate an orthogonal resource to multiple users by introducing new dimensions such as power domain, thereby improving the spectrum efficiency of the system [2]

Objectives

Results

Conclusion