Sequential Spectrum Detection Based On Multi-antenna Spatial Correlation

With the development of wireless communication technology, the wireless business anduser requirements also be growing, they fixed take up a lot of different wireless spectrumresources, which result in radio spectrum resources gradually scarce. The other main reason isthat the static spectrum allocation strategy led to a large number of frequency bands allocatedhas not been effectively utilized. Therefore, cognitive radio system based on dynamicadaptive spectrum allocation has appeared. As the first step of the cognitive radio system, thespectrum detection technology is the key and difficult point of the cognitive radio system.Spectrum detection technology can be divided into single-point spectrum detection andcooperative spectrum sensing. Single-point spectrum detection includes matched filtering,energy detection, cyclostationary detection, while cooperation sensing integrates the results ofthe single-point detection and then makes a judgment. In recent years, foreign researchersproposed the multi-antenna spatial correlation spectrum detection algorithm. The algorithmbased on the fact that the observation noise processes are spatially uncorrelated, whereas anyprimary signal present should result in spatial correlation. Comparing with the energydetection, it has better detection performance at low signal to noise ratio.The above spectrum detection algorithms are fixed-time detection algorithm, the numberof its samples is fixed, even if the cognitive user can make a accurate judgment early, itcannot stop the sampling. In this paper, present the sequential spectrum detection algorithmbased on multi-antenna spatial correlation for the lack of fixed-time detection algorithm. Thenumber of samples random variation with the observed situation. Simulation results show thatthis algorithm more efficient at the same detection performance comparing with fixed-timedetection. Second user access the idle band or avoidance the authorized user quickly, therebyincrease the utilization of spectrum resources and reduce the interference to authorized users.