Achievable capacity of cognitive radio systems coexisting with a macro cellular system

A theoretical analysis of achievable capacity by a cognitive radio systems is discussed, when the cognitive radio system (CRS) uses spectrum allocated to a macro cellular system. As for the spectrum sharing mechanisms, we consider two methods based on listen-before-talk and adaptive transmit power control principles. Moreover, outdoor and indoor installations of CRS stations are investigated. Numerical results reveal capacities achieved by CRS base stations installed within the coverage area of the macro cell system.