DF-based cooperative spectrum sensing in multi-antenna cognitive radio network

Unlike the previous research of single-antenna spectrum sensing, in this article we discuss the DF-based cooperative spectrum sensing technology in multi-antenna cognitive radio network. The key problem in multi-antenna system is that how to allocate power in each antenna at the transmitter. To solve this problem, we propose an iterative power allocation algorithm using Singular Value Decomposition (SVD) which implements the power water-filling on each antenna to achieve its maximum capacity. The performance of multi-antenna cooperative spectrum sensing is analyzed by decomposing the multiple antennas into parallel sub-channels which are independent of each other. Theory analysis and simulation results show that cognitive users with multi-antenna can not only raise the channel capacity, but can also improve the detection probability and reduce the outrage probability of the system.