Channel and Power Adaptation for Cognitive
Radios in Multiuser OFDM Systems
Abstract— we investigate joint power and channel allocation problem for the orthogonal frequencydivision multiplexing (OFDM) based multi-user cognitive radio systems with quality-of-service (QoS) in terms of signalto- interference-plus-noise ratio (SINR) and proportional rate constraints. The QoS requirement of each cognitive radio user imposed by its minimum SINR and interference introduced by unlicensed secondary users to primary users make power and channel allocation problem more complex. We present a formal analysis for a proposed approach and illustrate the approach with numerical results obtained from simulations. < final year projects >
