关键词: 认知无线电, 信号检测, 能量检测, 多天线

Abstract: Energy Detection（ED） is one of the most common method of signal detection, which has the advantage of low complexity and unrequired prior information of signals. When the noise variance is known, the energy detection algorithm can obtain better detection performance. In most cases, the variance of the noise is required to be estimated, so the uncertainty of the noise variance estimation will have a big impact on the performance of the energy detection algorithm. To minimize the effects caused by the uncertainty of noise variance, an improved multi-antenna energy detection scheme is proposed. The program takes a simple combination of the signal with multiple antennas to construct a decision statistic, which is independent of the noise variance. Theoretical formula shows the probability of detection and probability of false alarm in this program is independent of the noise variance. Simulation results show that when the number of the antenna is more than 3, the detection performance of the program better than conventional energy detection performance.

Key words: cognitive radio, signal detection, energy detection, multi-antenna