Cooperative spectrum sensing via coherence detection

Efficient and reliable spectrum sensing plays a critical role in cognitive radio networks. This paper proposes a cooperative sensing scheme that detects the existence of a common signal component in the signals received by multiple geographically distributed radios. The scheme assumes that signals received by different radios display strong coherence if they have a common source. Detection of this coherence in a wireless environment is studied, especially when the transmitted signal is distorted by multipath channels.