College of Telecommunication Engineering;
Hangzhou Dianzi University;
Hangzhou 310018;
China;
Institute of Information and Communication Engineering;
Zhejiang University;
Hangzhou 310027;
China;
OFDM-based Cognitive Radio Networks (CRN); Subcarrier allocation scheme; Worst Subcarrier Avoiding Water-filling (WSAW); Rate Adaptive (RA) criterion;