基于CCS-MUSIC的宽带无模糊测频方法研究

Research on Unambiguous Wideband Frequency Estimation Method Based on CCS-MUSIC

针对电子侦察机在宽带数字接收信号时由于时域欠采样引起的频率模糊问题,在双欠采样序列的互相关谱(Cross-Correlation Spectrum,CSS)的基础上,考虑到同时多信号时存在伪谱峰,提出在互谱峰值附近进行多信号分类(Multiple Signal Classification,MUSIC)谱搜索的方法,解决了欠采样信号模糊频率区间定位的问题,且在降低MUSIC谱搜索量的同时提高了频率估计精度.仿真结果表明,该方法在搜索量降低的优势下能实现宽带侦收时同时多信号的频率无模糊估计,且可以有效抑制噪声干扰对测频精度的影响,可服务于情报侦察.

For the problem of frequency aliasing due to the time domain undersampling in wideband received signal for electronic reconnaissance aerial vehicle,a method based on CCS（cross-correlation spectrum,CCS）of two independent samples for frequency estimation was proposed.Considering spurious peaks when multi signals simultaneous existed,the method of selecting frequency range around each cross spectral peak before using MUSIC（multiple signal classification）algorithm to complete frequency search solved the problem of aliasing zone location and improved frequency estimation.The simulation result indicates that multi signals frequencies are estimated unambiguously in wideband receiving under the circumstance of small search load and noise disturbance of frequency measurement accuracy is effectively suppressed.The method can work for elint.