An Optimal Joint User Association and Power Allocation Algorithm for Secrecy Information Transmission in Heterogeneous Integrated Networks

Abstract

In recent years, radio access technologies have experienced rapid development and gradually achieved effective coordination and integration, resulting in heterogeneous networks (HetNets). User equipments (UEs) located in the overlapping area of various networks of HetNets are capable of selecting the base station (BS) of one network for association and conduct information interaction. In this paper, we study user association and power allocation problem for HetNets with eavesdroppers. To achieve secrecy data transmission in a secret and energy-efficient manner, the concept of joint secrecy energy efficiency of the network is introduced and is defined as the ratio of secrecy transmission rate and the power consumption of the BSs. An optimization problem is formulated which maximizes the joint secrecy energy efficiency under the constraints of maximum power of the BSs and the minimum data rate requirement of the UEs, and the optimal user association and transmit power strategy is obtained through applying iterative algorithm and Lagrange dual method. Numerical results demonstrate the efficiency of the proposed algorithm.