Fast spectrum sensing using a large number of receive antennas

In this paper, we propose a novel spectrum sensing method to detect the presence of a primary user in a cognitive radio network when the secondary user is employing a large number of receive antennas. The new method is a suboptimal approach based on the generalized likelihood ratio test (GLRT), but unlike the previous GLRT-based methods which rely on large number of received samples obtained over time, we take advantage of the large number of samples available at the receive antennas. By exploiting the properties of the samples obtained at the receive antennas, effective spectrum sensing is achieved using mainly the spatial samples and therefore the sensing time is significantly reduced. With the suitable channel models and prior knowledge about the signal structure, the simulation results show that the proposed method offers performance comparable to well-known methods but with much smaller sensing time.