Implementation of Cyclostationary Feature Detector for Cognitive Radios

Spectrum sensing is needed in cognitive radios to provide information about the surrounding radio spectrum. This enables cognitive radio system to communicate among existing radio systems without interfering them. This paper describes an FPGA implementation of a cyclostationary feature detector, which has an improved detection performance achieved by decimation of the cyclic spectrum. Decimation also provides a simple way to control detection time and, thus, allows trading the detection time to better probability of detection and vice versa. Measured detection performance is presented and detection of a 802.11g WLAN signal from air is demonstrated.