Spectrum Sensing of OFDM Waveforms Using Embedded Pilot Subcarriers

Reliable spectrum sensing is the key requirement for secondary users to utilize the spectrum in the absence of primary users. Given the widespread deployment of OFDM modulation in recent and future multimedia broadcasting and wireless broad-band services, reliable spectrum sensing of OFDM waveforms is of great interest for future cognitive radio systems. This paper presents a new detection method for OFDM waveforms that exploits the available embedded pilot tones without any simplifying assumption or constraints on the pilots. Analytical performance characterization is presented and supported by simulation results for both AWGN and fading channels. This study shows that the new method can improve the performance by 5dB in comparison with other feature detectors.