Joint effect of power control, access control, and multi-hop transmission on area spectral efficiency of cognitive radio system

The joint effect of power control, access control, and multi-hop transmission on spectral efficiency of a cognitive radio system is evaluated, focusing on the trade-off between the performance of a high priority system and that of a low priority system. So as to avoid interference to the high priority system, the low priority system is assumed to reduce transmit power through power control or stop transmission through access control by using information such as path loss. However, excessive power control or access control would decrease the area spectral efficiency of the low priority system. In this context, the effects of multi-hop transmission, in addition to power control and access control, on the area spectral efficiency is evaluated. Simulation results reveal that the combination of multi-hop transmission and power control can significantly increase the area spectral efficiency of the cognitive radio system.