Multiple Primary User Spectrum Sensing in the Low SNR Regime

We consider multi-antenna cooperative spectrum sensing in cognitive radio networks, when there are multiple primary users and/or multipath channels. A noise-uncertainty-free detector that is optimal in the low signal to noise ratio regime is analyzed. We derive the moments of the test statistics involved, which lead to simple and accurate analytical formulae for the key performance metrics. The approximative false alarm and detection probabilities as well as receiver operating characteristic are given in closed form. From the considered simulation settings, performance gain over several known detection algorithms is observed in scenarios with relatively low signal to noise ratio.