Research on Cooperative Transmission Scheme Based on Cooperative Diversity and Its Outage Performance in Cognitive Radio Networks

In Cognitive Radio Networks (CRNs), cognitive users(CRs) access a spectrum hole, which promotes the efficient utilization of the licensed spectrum, and solve the problem of increasing demands for the wireless radio spectrum with the emergency of many new wireless communication networks. However, in order to satisfy the quality of service (QoS) requirement for primary users (PUs), the transmission performance of CRs shall be limited. In this paper, we propose a new cooperative transmission schemes based on cooperative diversity protocol while PU and CUs coexist in the same CRNs and each PU can be either active(ON) or inactive (OFF) in any given slot. Analytical expression of the outage probability was given. Non-cooperative and cooperative schemes were derived show the effect of cooperative transmission on the outage probability performance. Besides, numerical experiments were conducted to verify the effectiveness of the proposed cooperative schemes. The increase of outage probability performance by cooperative transmission confirms the advantages of our new scheme and transmission performance of CRs in CRNs can be improved without interfering the regular transmissions of the primary users (PU).