Design and Analysis of Downlink Spectrum Sharing in Two-Tier Cognitive Femto Networks
In two-tier networks consisting of a macrocell overlaid with femtocells in co-channel deployment and closed-access policy, spatial reuse is achieved at the price of severe intra-tier and cross-tier interference from concurrent transmissions. The interference causes significant performance degradation, particularly when coordination among Base Stations (BSs) is infeasible. Cognitive Radio (CR) is a promising technique for interference mitigation, where femto-BSs with cognitive information accomplish concurrent transmissions while meeting a per-tier outage constraint. This paper studies the role of information sensed at femto-BSs on the transmission capacity.