Efficiency of energy detection for spectrum sensing in the presence of non-cooperating secondary users

Spectrum sensing is an important task of a cognitive radio. An effective spectrum sensing algorithm enables the cognitive radio to transmit without causing harmful interference to the licensed user. However, in a multi-user environment, the aggregate interference to the sensing node may adversely affect its sensing performance. In this paper, we investigate the performance of a sensing node in the presence of unlicensed user interference in a non-cooperating secondary network. New expressions were developed to calculate the false alarm and detection probabilities of an energy detection sensor and the results obtained were verified using Monte Carlo simulation techniques. The method employed in this paper significantly reduces the computational task of otherwise directly computing the random interferer variance and hence the results could be used to design more efficient sensors.