Resource allocation scheme using proportional fairness for cognitive radio networks
Zhou Liuj · Computer Engineering and Applications Journal · 2015
In OFDM-based cognitive radio network, the Amplify-and-Forward(AF)scheme is used by cognitive users as cooperative strategy for data transmission. This paper presents a power and subcarrier allocation and pairing scheme(OFDM-PASA). It is considered that an interference-limited environment, with a transmit sum-power constraint over all channels as well as an aggregate average interference constraint towards Primary User(PU). The Lagrange decomposition algorithm and sub-gradient algorithm are used to solve the problem of power allocation, and subcarrier allocation and pairing algorithm is also derived. It is shown by simulation results that proportional fairness(maximize-pro-fair)is a well-balanced criterion between efficiency and fairness compared with maximize-total fairness and maximize-worst fairness. In addition,the proposed new resource allocation and subcarrier pairing strategies can achieve substantial transmission efficiency and fairness for the secondary user over the other methods when the Signal-to-Noise Ratio(SNR)is low.