改进多重信号分类算法的宽带频谱快速感知方法

针对宽带频谱感知中采样率大、感知时间长的问题，在调制宽带转换器采样的基础上提出了一种改进多重信号分类算法的宽带频谱快速感知方法。调制宽带转换器对宽带频谱进行欠奈奎斯特采样，以最小描述长度准则估计信号个数，用改进多重信号分类谱估计信号位置。算法引入调整因子，使得多重信号分类谱中信号位置更为明显，降低了噪声的干扰。整个感知过程无须重构原始波形，无须计算频谱，大大降低了计算量，而且感知算法计算复杂度低，提高了感知效率。仿真结果表明，在低信噪比的情况下，该算法仍具有很好的检测性能。
Aiming at the problem of exorbitant sampling rate and sensing time too long in wideband sensing, a wideband spectrum sensing method using improved multiple signal classification (MUSIC) based on modulated wideband converter (MWC) was proposed. The MWC for sub-Nyquist sampling was used, the number of signals by minimum description length (MDL) criterion was estimated, and the signals’ location using improved MUSIC was estimated. In the improved MUSIC, an adjustment factor was given, which enhanced the MUSIC spectrum at the signal’ locations and reduced others, and the noise jam was restrained. An amount of calculations was reduced, because it neither needed to recover original wave, nor calculated PSDs in the whole process. The complexity of sensing method was small, so that it increased sensing efficiency. The results show a reliable detection even in low signal noise ratio.