A distributed algorithm to select channel and relay in multichannel-multirelay CR-networks

Abstract

Channel selection in multichannel cognitive radio system and relay selection in multi-relay cooperative system are well studied problems in separate branches. In this study, we consider a joint channel and relay selection problem which is very important to realize multi-relay cooperative transmission in multichannel cognitive radio networks. A joint channel and relay selection algorithm is proposed for amplify-and-forward relaying. A distributed implementation of the proposed joint channel and relay selection algorithm is also presented. As a measure of the channel quality, we consider a crosslayer approach where physical layer channel state information and link layer collision probability of the channels are used as selection parameters. In the joint channel and relay selection, the channels for two phases of cooperative transmission and a single-relay that maximizes the end-to-end mutual information is selected. We show that proposed relaying schemes significantly improve the achievable rate of the system.