Performance Analysis of NOMA System using Fair Power Allocation Policy

Abstract

This work addresses the problem of fair power allocation policy in non-orthogonal multiple access (NOMA) system. NOMA is the multiple access (MA) scheme where data corresponding to multiple users are superimposed at the base station (BS). Data decoding at each user is done by employing successive interference cancellation (SIC) strategy. The transmission of multiple users' data over the same carrier enables to get a better bandwidth efficiency and high achievable capacity, which are the fundamental requirements in 5G communications and beyond. Conventionally, power allocation in NOMA is done based on channel conditions of the corresponding users. Users with weak channel conditions are allocated more power as compared to users with good channel conditions. Hence, to address the fairness, we have proposed a fair power allocation scheme. The proposed low complexity iterative algorithm is developed based on the maximization of the rate of the user with worst channel condition. Simulation results shows the significant improvement in minimum achievable rate as compared to conventional orthogonal multiple access (OMA) scheme for different number of users.