PROJECT TITLE :

Interference Management Through Exclusion Zones in Two-Tier Cognitive Networks - 2016

ABSTRACT:

The transmission capacity of wireless networks is limited by the intensity of the interference received from concurrent transmissions. Interference causes serious performance degradation, particularly when no centralized controller among the network exists. Cognitive radio (CR) could be a promising solution for distributed interference management as users with CR capabilities can acquire local activity and position data to attain spatial reuse whereas limiting interference to neighboring users. Considering a two-tier network consisting of a licensed primary network overlaid by an unlicensed secondary tier, this paper proposes CR-based mostly spectrum access schemes for secondary users (SUs). Acquiring the activity info of nearby users, the SUs are activated only after they are outside the exclusion zone of primary receivers. Additionally, the active secondary transmitters are separated from every other by forming secondary exclusion zones around themselves. Using stochastic geometry, primary and secondary exclusion zone sizes that maximize the transmission capability beneath per-tier outage constraints are calculated. Analytical results supported by numerical simulations, recommend primary exclusion zones cut back predominantly the cross-tier interference whereas the secondary exclusion zone size is critical in mitigating the interference among SUs.