Abstract

Previous works on cooperative spectrum sensing scheme assume that the sensing information from different secondary users (SUs) is reported in a time-division manner to the base station (BS) without error. However, reporting overhead increases with the number of cooperative SUs and reporting process has no contribution to the sensing performance. In this paper, we consider that the reporting channels are characterized by fading channels and propose a cooperative spectrum sensing scheme in which the BS is equipped with multi-antennas. Sensing information of SUs is simultaneously transmitted to the BS to reduce reporting overhead. The BS estimates the sensing information of each SU by exploiting multi-antennas. Then we allocate weighting coefficients to the estimated sensing information and conduct weighting coefficients optimization in order to maximize the detection probability at the BS. Soft combination scheme of cooperative spectrum sensing is studied. Compared with the conventional scheme, the proposed scheme greatly reduces reporting overhead and simulation results verify sensing performance in the proposed scheme is also satisfied.

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