Joint Optimization of Power and Filter-and-Forward Beamforming in Cognitive Networks with Frequency Selective Channels

In this paper, we propose a filter-and-forward (FF)beamforming strategy in the secondary relays for the one-way cognitive relay network with frequency selective fading channels. Our aim is to optimize the beamforming coefficients and the secondary transmitted power to maximize the SINR at the secondary destination, while satisfying the interference constraint on the primary network and the total relays´ transmitted power restriction. To solve this problem, we propose a two-step iterative algorithm. Simulation results show that comparing the amplifyand-forward (AF) strategy, the filter-and-forward strategy (FF) can get higher SINR at the secondary destination by using the algorithm that we proposed.