Spectrum Sensing for FM Wireless Microphone Signals

Spectrum sensing of FM wireless microphone signals under strong interference is a very challenging task. To address this problem, we develop a simple spectrum sensing algorithm that utilizes an important property of an FM signal, i.e., its autocorrelation function can be approximated as a sinusoidal function provided that the frequency deviation is much smaller than its carrier frequency and the correlation delay is small. Computer simulations demonstrate that the proposed spectrum sensor can reliably detect the target signals when a strong adjacent channel interference exists and the signal power is as low as -114 dBm set by FCC.