Power Allocation and Performance Analysis of Multiuser NOMA under NYUSIM Channel Model

Non Orthogonal Multiple Access (NOMA) is a promising technique for fifth generation (5G) wireless cellular networks with the aim to achieve capacity goals and better performance. Generally, power domain NOMA is tested for two user equipment (UE) based systems. Capacity improvement of NOMA system with accurate power allocation is a key challenge. To meet this challenge, different techniques are been introduced. In this paper, basic NOMA model with two users is extended for multiple users to achieve higher capacity. We implement NOMA with three and four UE's, where superposition coding is introduced at the transmitter side and Successive Interference Cancellation (SIC) at the receiving end. With increased number of NOMA users, a crucial problem is to accurately allocate transmit powers for all the users. A main contribution of this paper is the selection of accurate power allocation and modulation schemes based on BER performance. Furthermore, the proposed multiuser NOMA scheme is simulated in 5G path loss model namely NYUSIM Channel Model. This paper provides foundation of accurate power allocation mechanisms for NOMA based systems in the future.