Selection of Relays and Clustering For Spectrum Sharing

A wireless communication system comprising of primary users and secondary users. The secondary users access the channel of primary users when the channel is free (spectrum sharing). There may be a chance of interference on primary system. Inorder to minimize this interference relays are used at secondary. Clustering schemes are used too improve the secondary rate. Here as the number of relays increases the interference on primary diminishes as well as secondary rate goes up. Alternate relay protocol is employed. It helps to reduce half duplex loss.