Secrecy-Based Resource Allocation for Vehicular Communication Networks with Outdated CSI

Abstract

This paper proposes a resource allocation policy which enhances physical layer security in vehicular communication networks. Due to the high mobility in vehicular networks, the feedback channel state information (CSI) can easily get outdated, especially when it takes non-negligible time to obtain the resource-allocation solution. Under the assumption that only outdated CSI is available, we formulate the problem as joint power and subcarrier allocation in order to optimize the uses' secrecy rate based on maximum-minimum (max-min) fairness criterion. The formulated optimization problem is a mixed integer nonlinear programming problem. To reduce the complexity, we further propose a two-step suboptimal algorithm that performs power and subcarrier allocation separately. For a given subcarrier assignment, the optimal power allocation is solved by developing an algorithm of polynomial computational complexity. Numerical results show that the performance of our proposed algorithm can approximate to the optimal one.