Symbol error probability optimization in cognitive amplify and forward cooperative relaying networks

Abstract

This paper considers a resource scheduling problem of a cooperative cognitive radio network based on orthogonal frequency division multiplexing technology, in which primary and secondary users enjoy different priorities. Our goal is to minimize the symbol error probability of secondary users while assuring the quality of service for primary users due to higher priority and payment guarantees. Different from the usual energy efficiency, spectrum efficiency, sum rate or throughput issues, the symbol error probability is recruited as the optimization goal. According to different power rationing and quality of service requirements, the joint algorithm of power and subcarrier allocation is divided into four cases: total power budget and total interference level, total power budget and separate interference level, separate power budget and total interference level as well as separate power budget and separate interference level. For each scenario, a detailed analysis is carried out to obtain a closed-form solution of the power allocation, and the decision basis of the path selection is strictly proved. Simulation results show that the joint algorithm of power allocation, path selection and subcarrier pairing has excellent performance in relay location deployment, convergence analysis and symbol error probability reduction.