Power Allocation Scheme for Secondary User under Primary Full Duplex Relay System in Cognitive Radio Network

A power allocation scheme for the secondary user when the primary user employs the full duplex relay (FDR) is proposed in cognitive radio system. When the FDR is deployed in primary system, the primary relay and receiver suffers the interference from the secondary transmitter in order to share the spectrum of the primary user. Therefore, the power allocation scheme to satisfy the interference constraint is needed for the spectrum sharing. Thus, we propose a new power allocation scheme to satisfy the quality of service (QoS) of the primary user. Since the proposed power allocation scheme does not need the instantaneous channel state information (CSI), the proposed scheme not only has feedback burden, but also can be robust the outdated CSI environment.