Abstract
Non-orthogonal multiple access (NOMA) plays an important role in achieving high capacity for fifth-generation (5G) networks. Efficient resource allocation is vital for NOMA system performance to maximize the sum rate and energy efficiency. In this context, this paper proposes optimal solutions for user pairing and power allocation to maximize the system sum rate and energy efficiency performance. We identify the power allocation problem as a nonconvex constrained problem for energy efficiency maximization. The closed-form solutions are derived using Karush–Kuhn–Tucker (KKT) conditions for maximizing the system sum rate and the Dinkelbach (DKL) algorithm for maximizing system energy efficiency. Moreover, the Hungarian (HNG) algorithm is utilized for pairing two users with different channel condition circumstances. The results show that with 20 users, the sum rate of the proposed NOMA with optimal power allocation using KKT conditions and HNG (NOMA-PKKT-HNG) is 6.7% higher than that of NOMA with difference of convex programming (NOMA-DC). The energy efficiency with optimal power allocation using DKL and HNG (NOMA-PDKL-HNG) is 66% higher than when using NOMA-DC.
Highlights
The development of different multiple access techniques for each generation has brought many advantages to wireless cellular communication, such as improving spectral and energy efficiency and achieving a high data rate
The base station (BS) is located at the center of a circle with radius R = 500 m, and there is a random distribution of M users in the cell coverage
Non-orthogonal multiple access (NOMA) assigns only two users to each subchannel, and OMA assigns a single user to each subchannel
Summary
The development of different multiple access techniques for each generation has brought many advantages to wireless cellular communication, such as improving spectral and energy efficiency and achieving a high data rate. An optimal user pairing approach based HNG algorithm is proposed that considers pairing of only two users at each subchannel This algorithm guarantees an optimal performance of both the sum rate and energy efficiency maximization process in a downlink NOMA system. To solve this problem and obtain the optimal power for each of the paired users in a subchannel, a power allocation solution is proposed based on Karush–Kuhn–Tucker (KKT) conditions (PKKT). The energy efficiency maximization problem is formulated with power constraint consideration, and SIC is applied to reduce complexity at the receiver To solve this problem and obtain the optimal power for the multiplexed users, we propose a power allocation solution using.
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
