Cognitive System Scheme Design Based On Side Information

Cognitive radio is viewed as a novel approach for improving the utilization of the radio electromagnetic spectrum. Significantly greater spectral efficiency could be realized by deploying cognitive (secondary) users that can coexist with the incumbent licensed (primary) users, generating minimal interference while somehow taking advantage of the available resources.Based on the cognitive radio channel model, we formulate the optimization problems of the cognitive system under two modes:the Overlay and Interweave. We further propose a joint optimization algorithm for the Overlay mode, which combines elements of compress-and-forward relaying with coding for the pure cognitive radio channel model, to solve the problem. Simulation results demonstrate that the proposed compress-and-forward based strategy achieves good performance. With respect to the Interweave mode, we design a practical scheme for the relay forwarding. This scheme exploits the Quantize-and-Forward (QF) and Compressive Sensing (CS), aiming to make full use of the diversity, in order to restore the original sparse signal at source node through as less measurements as possible.Based on the Matlab simulation results, it is showed that the proposed joint optimization algorithm could solve the achievable rate optimization problem in Overlay cognitive system. It can maximize the achievable rate of secondary user; while ensuring the primary user’s achievable rate performance. As to the practical scheme for relay forwarding under interweave mode. We assess and compare the performance of the proposed scheme under AWGN channel. Simulation results demonstrate that the proposed schemes achieve excellent recovery performance with reduced communication overhead.