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由于无线通信技术的飞速发展,因此无线资源频谱日趋紧张。而另一方面现有无线通信网络采用的固定频谱分配策略导致许多已分配的频段在大多数情况下未能被充分利用。认知无线电技术的出现为提高频谱利用率提供了一条新的思路。认知无线电的一个重要要求就是能够动态的感知并接入频段,这就需要人们能够感知出空闲频段。论文主要介绍了认知无线电系统中的频谱感知方法,并运用能量检测法对对OFDM信号进行了仿真分析。
Due to the rapid development of wireless communication technology, the spectrum of wireless resources is becoming increasingly tense. On the other hand, the fixed spectrum allocation strategy adopted by the existing wireless communication networks results in many allocated frequency bands being underutilized in most cases. The emergence of cognitive radio technology provides a new idea for improving the efficiency of spectrum utilization. An important requirement of cognitive radio is to be able to dynamically sense and access the frequency band, which requires people to be aware of the free frequency band. The thesis mainly introduces the spectrum sensing method in cognitive radio system, and uses the energy detection method to simulate the OFDM signal.