Resource allocation for secure OFDMA communication systems

In this paper, resource allocation and scheduling in an orthogonal frequency division multiple access (OFDMA) downlink network is studied. The considered problem is modeled as an optimization problem which takes into account a multiple antenna eavesdropper and artificial noise generation for secure communications. Power, secrecy data rate, and subcarrier allocation are optimized for maximization of the average secrecy outage capacity (bit/s/Hz securely delivered to the users). The optimization problem is solved by using dual decomposition resulting in an efficient iterative resource allocation algorithm. Simulation results illustrate that the proposed iterative resource allocation and scheduling algorithm converges in a small number of iterations and guarantees a non-zero secrecy date rate even if the eavesdropper is closer to the base station than the desired users.