On Spectrum Sharing in Cooperative Multiple Access Networks

The coexistence and resource sharing between a primary network utilizing cognitive relays and a secondary network are investigated. Two multiple access protocols are proposed to coordinate idle time slots sharing between the two networks in a TDMA setting. While relays in the primary network are using these free time slots to help users in the primary network forward their unsuccessfully transmitted packets, users of the secondary network use these time slots to transmit their own packets. The diversity-multiplexing sort of tradeoff imposed by this resource sharing problem and optimum resource allocation strategy are studied through the characterization of the maximum stable throughput region of both networks.