Multisource multirelay scheme within an underlay cognitive radio network

This paper investigates the performance of Multisource Multirelay Cognitive Radio Network (MMCRN). Underlay spectrum sharing is used to achieve efficient spectrum utilization while limiting the interference level on the Primary User (PU) with an average interference power constraint. One source and one relay are selected for Secondary User (SU) transmission based on maximizing the SU effective capacity (EC) of the transmission channel. Practically, this paper studies the MMCRN with assuming Imperfect Channel State Information (ICSI) of the interference link between the SU source (SS) and the PU destination (PD). Performance analysis measurement in terms of SU EC is derived for the proposed system model when there is an average interference power constraint and with considering ICSI. The proposed numerical analysis demonstrates the quasi-optimal number of relays that should be used to obtain an efficient SU EC. In addition, the obtained results investigate the effect of the interference channel imperfection on the measurement metric with different parameters such as the number of SUs and the SU statistical delay QoS constraint.