Institute of Electrical & Electronic Engineers
This paper considers the resources allocation problem in Decode-and-Forward (DF) relayed OFDM based Cognitive Radio (CR) system. The subcarrier matching and power allocation are optimized jointly under the individual power constraints in source and relay so that the sum rate is maximized while the interference induced to the primary system is kept below a pre-specified interference temperature limit. Therefore, the dual decomposition technique is adopted to obtain an asymptotically optimal solution. Moreover, a suboptimal scheme is presented to get rid of the high computational complexity of the optimal scheme. The suboptimal algorithm solves the problem in two phases.