Cooperative Jamming for Secure Communication With Finite Alphabet Inputs

Abstract

This letter considers cooperative jamming to secure communication in the presence of multiple eavesdroppers with finite alphabet inputs. Considering the global constraint, the joint design of artificial noise covariance matrices and power allocation between the source and the relays is studied. Specifically, we transformed the problem of artificial noise design into a semi-definite programming problem, which is efficiently solved by standard optimization method. Besides, the power allocation between the source and relays is derived by utilizing the relationship between mutual information and minimum mean square error. Furthermore, a two-step algorithm is developed to enhance the achievable secrecy rate of cooperative jamming wireless network. Numerical examples demonstrate the proposed algorithm achieves a significant gain over the conventional counterparts in terms of secrecy rate.