Joint Power and Channel Allocation Based on Caching with User Preferences in D2D HetNets

Abstract

Device-to-device (D2D) and caching can effectively solve the problem of repeated transmission of plentiful short videos in wireless networks. This paper considers a downlink video transmission process among cellular users and D2D users with interference between co-channel users. Caching with user preferences in D2D users is also taken into consideration to improve the system capacity. Joint channel and power allocation is optimized to maximize the sum rate of all users. The problem is a mixed integer nonlinear programming (MINLP) and is hard to solve. Firstly, the concept of cache similarity distance based on user preferences and video popularity is introduced to divide users into different groups. Then, the optimization problem is decoupled into two sub-problems. And a joint channel and power allocation algorithm based on caching with user preferences is proposed. Besides, a penalty function is introduced to handle constraints and a speed update function is modified to optimize binary variables and continuous variables simultaneously. Finally, an improved particle swarm optimization algorithm (PSO) is proposed to solve the problem. Simulation results show that the proposed algorithm can effectively improve the system capacity of the network.