【作者】 杨杰；

【导师】 李式巨；

【作者基本信息】 浙江大学 ， 信息与通信工程， 2010， 硕士

【摘要】 认知无线电技术是当前现有频谱分配政策下,克服频谱资源短缺的有效手段,而频谱感知则是这项技术的前提。本文以循环平稳检测为研究的基本路线,通过分析接收信号的循环平稳特征,来判别当前状态下频谱的使用情况。本文以Dandawate频域渐近最优χ2检测法为基础,提出了一种在一定先验信息条件下的特定频率检测法,该方法在低信噪比条件下依然具有良好的检测性能。同时描述了在OFDM信号中嵌入循环平稳特征值的低复杂度技术,分析了嵌入单个循环平稳特征值与多个循环平稳特征值后的检测性能,以一定的数据传输损失为代价,换取在复杂环境下良好的信号检测能力,通过仿真表明,本文提出的方法在低信噪比及多径瑞利衰落环境下,对嵌入循环平稳特征值后的OFDM信号具有较高的检测概率。更多还原

【Abstract】 Cognitive radio is an effective method to overcome the scarcity of frequency spectrum resource under the current frequency spectrum distribution policy while frequency spectrum cognitive is the prerequisite of this technology. This dissertation analyzes the frequency spectrum’s usage condition through the receiving signal’s cyclostationary feature based on the cyclostationary detection study.This paper proposed a special frequency detection method based on a certain priori information in accordance with Dandawate frequency domain asymptotic optimalχ2 detection. This method has good detection performance even the SNR is low. At the same time the paper presented the low complexity technology of the OFDM signal embedded with cyclostationary signature and analyzed the detection performance embedded with single cyclostationary and multiple cyclostaionary signatures in details. At the cost of data transmission loss, we can obtain the good signal detection capacity under the complex environment. The simulations demonstrate that these methods have the high detection probability for the OFDM signal embedded with cyclostationary signature even under the low SNR and multipath Rayleigh fading channel environment.更多还原