Research On Spectrum Sensing Technology In Cognitive Radio

Spectrum sensing technology is used to quickly and accurately find the spectral holes in wireless environment so that the rental user can use the spectral holes to transmit information, without causing interference to the primary user’s transmission, and thus can improve the utilization of spectrum resources. The technology is also one of the key technologies of cognitive radio techniques. The cognitive radio spectrum sensing technology is described in this thesis. First, single-user spectrum detection is researched and a simple binary decision model at primary users transmitting terminal is established, and several algorithms are simulated.Shadow effects and multipath fading in actual wireless communication environment make the enhancement of the sensing performance of the single user algorithm encounter a bottleneck. Multi-user collaborative spectrum sensing algorithm can reduce the impact of shadow effects, etc. and it also is studied in this paper, including simulating and analyzing the sensing performance of the Multi-user algorithm.With the development of communication technology, spectrum sensing technology also encountered a number of challenges and difficulties. According to the Nyquist theorem, sampling the received signal requires a higher sampling rate for the perception in the broadband scene, which makes the overhead of broadband spectrum sensing be relatively high. To solve this problem, a spectrum sensing method based on compression is presented. First, the theoretical basis of spectrum sensing method based on compression, namely the compressed sensing theory, is discussed. Then with a combination of compressed sensing theory and the maximum and minimum values detection, the compression spectrum detection algorithm based on the maximum and minimum eigenvalues is studied and its sensing performance was simulated and analyzed.