On the implementation of autocorrelation-based feature detector

Emerging wireless systems demand more spectrum in order to provide high data rate services. It is known that most of the licensed frequency bands are underutilized because of the rigid spectrum allocation. Cognitive radios aim to relief the situation by identifying and exploiting the underutilized radio spectrum. A key task of the cognitive radio is spectrum sensing, which finds free spectrum and detects licensed spectrum user transmissions. This paper presents an FPGA implementation of an autocorrelation-based feature detector for OFDM-based primary user signals. The autocorrelation-based detection algorithm is optimized in order to achieve power and area efficient hardware realization. The algorithm is implemented in an FPGA evaluation environment, and the performance is verified with measurements.