A Spatial Spectrum Reuse Architecture and Its Analysis∗

Due to the recent spectrum scarcity challenges, a cognitive radio approach has been proposed to opportunistically reuse the allocated spectrum for efficiency purposes. Different from cognitive radio, which is non-collaborative in general, we propose a spatial spectrum access architecture for reusing the spectrum allocated to standard commercial wireless systems, such as GPRS, in which the secondary systems only share the uplink band of the primary systems at sufficient distance from the base stations of the primary system. Specifically, we discuss the coexistence of GPRS and WiFi by signal propagation and interference analysis. In addition, we validate our system architecture using simulations. Results show that the WiFi systems sharing the GSM900 uplink create negligible impact on the performance of the GPRS system, and our system architecture is a feasible solution to the spectrum scarcity issue.