Multiple Antennas Spectrum Sensing for Cognitive Radio Networks
Performance of cooperative spectrum sensing with multiple antennas at each cognitive radio is discussed in this paper. A new algorithm based on auto-correlation is proposed in which the optimal weights are obtained for each antenna in case little priori knowledge of channel characteristics as well as noise is known. In multiple antennas spectrum sensing, As long as the antenna characteristics are similar, the detection probability can be improved if more antennas are involved. However, if the antenna characteristics are quite different or the number of poorly performed antenna is large the detection probability deteriorates. Therefore, the well-performed antennas are selected in order to improve the detection probability. The performance of an antenna is obtained to determine whether it is deployed to sense the spectrum. A criterion is proposed to select the well-performed antennas to sense spectrum. Simulations are used to verify the method. The results indicate that the proposed antenna weighting and selection algorithm can be able to optimize network performance.