NoMA-based D2D and Cellular Bidirectional Communication Research

This paper proposes a NoMA-based D2D and cellular two-way relay cooperative transmission scheme to solve the problems of spectrum scarcity and insufficient signal coverage for edge users in wireless communication networks. While ensuring the minimum rate requirement for cellular uplink/downlink users, the scheme aims to improve spectrum utilization efficiency and service quality for edge users while minimizing overall system power consumption. The problem to optimize is non-convex. This is due to variable coupling and multi-user interference. To address this, we convert it to a convex problem using the first-order Taylor approximation. Then, we use the iterative algorithm of successive convex approximation in order to obtain the optimal solution. The proposed transmission scheme allows two-way cooperative communication between D2D and cellular networks in two timeslots and reduces the transmission power compared to the traditional scheme, thereby improving the transmission efficiency of the system.