Joint power and subcarrier allocation using auction games for secure multiuser OFDMA networks

Security is a critical issue in downlink multiuser orthogonal frequency division multiplexing access (OFDMA) networks. In this paper, we propose a joint power and subcarrier allocation algorithm to maximize secrecy rate. Specifically, we propose an iterative scheme to allocate transmit power for each subcarrier under the transmit power constraint. Furthermore, we propose two auction-based algorithms, i.e. Frist-price Sealed-bid Auction and Flexible-language Combinatorial Auction, to allocate the subcarrier among multiusers. Finally, simulation results are provided to indicate that the First-price Sealed-bid Auction has a better performance in improving the system secrecy rate while the Flexible-language Combinatorial Auction reflects more fairness among users in the subcarrier distribution. In addition, the flexible bidding language in the combinatorial auction is proved to achieve a higher secrecy rate than the traditional bidding language.