Energy Efficient Power Allocation for OFDM-Based Cognitive Radio Systems with Partial Intersystem CSI

摘要

This paper investigates energy efficientpower allocation for orthogonal frequency division multiplexing- (OFDM-) based cognitive radio (CR) systemswith partial intersystem channel state information (CSI)available. The goal is to maximize energy efficiency(EE) while ensuring the minimum rate of secondaryuser (SU) and keeping the average interference power(AIP) introduced to primary user (PU) within a targetprobability level. We propose a suboptimal algorithmto solve this optimization problem based on classicwater-filling (WF) technique. Moreover, we first addressthe relation between EE and water level. Inorder to reduce complexity, a simplified algorithm withclosed-form solution is also proposed. Numerical resultsare provided to corroborate our theoretical analysisand to demonstrate the effectiveness of the proposedschemes.