基于信号采样自相关的步进宽带频谱感知方法

采用步进频域能量检测法可以提高在软件无线电平台的频谱感知的带宽范围，但能量检测法易受噪声不确定性的影响，而信号采样自相关检测法对噪声不确定性有很好的鲁棒性。为进一步提高软件无线电的检测性能，提出了基于信号采样自相关的步进宽带频谱感知方法。首先阐述了信号采样自相关检测的原理，然后对基于该原理的步进宽带检测方法的流程进行了分析，最后利用MATLAB软件仿真其检测性能。仿真结果表明，在信噪比（Signal-noise-ratio, SNR）不同的情况下，基于信号采样自相关的步进宽带频谱检测方法能达到所要求的检测性能。此 外，为了兼顾频谱感知的检测速度和频带带宽分辨率之间的关系，进一步提出了在原本固定步进值的步进宽带信号采样自相关的频谱感知方法中采用可变步进值的两阶段检测方法，该方法可 以获得较高的频带带宽检测分辨率和较短的检测时间。

Step-by-Step Wideband Spectrum Sensing Method Based on Signal Sample Autocorrelation

The bandwidth of spectrum sensing can be enlarged in software radio pla tform by using multi-step frequency domain energy detection. Nevertheless, the energy detection is sensitive to noise uncertainty, and signal sample autocorrelation method is robust to it. To improve the detection performance of software radio, a step-by-step wideband spectrum sensing method based on signal sample autocorrelation is proposed. Firstly, the principle of signal sample autocorrelation and a step-by-step wideband spectrum sensing procedure based on it are described.Then, the whole procedure for wideband spectrum sensing using MATLAB is simulated. The simulation results demonstrate that our proposed method can achieve the required detection performance under different signal-noise ratio (SNR). In addition, to balance the bandwidth resolution and the detection speed, we further propose to apply variable step values in two stages of wideband spectrum sending based on signal sample autocorrelation detection, which can obtain higher detection resolution of the frequency bandwidth and shorter detection time.