差分二次平均修正的频域相位补偿线谱检测方法

An Algorithm of Line-spectrum Detection Using Frequency Domain Phase Compensation with Difference and TPM Technique

针对常规平均功率谱方法幅度平方后相位信息丢失造成检测性能损失问题,通过对观测数据分段进行快速傅里叶变换后的统计特性进行分析,提出了高斯噪声背景下检测未知线谱的频域相位补偿方法。采用蒙特卡洛法估计相位补偿因子,先进行差分法去除零星野值,然后使用二次平均(TPM)去除连续野值,最后使用估计的相位补偿因子均值构造广义似然比检验统计量实现检测。从理论上对比了广义平均周期图(AVGPR)法、广义功率谱(GPR)法及文中方法的检测性能。仿真结果表明,文中方法充分利用信号的相位信息,参数估计简单,相位补偿因子估计准确,在一定虚警概率下较AVGPR法的检测性能提高了接近5 dB左右。

The common average power spectrum estimation algorithm may cause the loss in detection performance because power spectrum amplitude is simply squared. The statistical properties of FFT of the segmented observations are analyzed,and a novel algorithm using frequency domain phase compensation for detecting line-spectrum in Gaussian noise is proposed. The phase compensation factor is estimated using Monte Carlo method. The sporadic and continuous outliers are removed by using difference and TPM method. Finally the statistics is checked by using generalized likelihood ratio. The detection performances of AVGPR,GPR and the proposed algorithm are theoretically compared. The simulation results show that the detection performance of the proposed algorithm is improved by 5 dB under a certain false alarm rate compared to AVGPR algorithm. It fully utilizes the phase information of the signal and has the advantagesof simple and exact parameter estimation and good robustness.