【摘要】 目前已提出的基于时频分析的DOA估计方法在多LFM信号源环境下性能不理想,抑制或消除交叉干扰项是提高方向估计性能的关键。提出了基于SPW变换的时频DOA估计方法,SPW结合了WVD与STFT的优点,在很好地抑制交叉项的同时,具有高的时频聚集性;它不需要对信号进行过采样,而且在降低运算代价方面具有显著优势。模拟实验表明,在多目标环境下,与基于PWVD和SPWVD的方法相比,基于SPW的方法的DOA估计精度有很大提高。如在信噪比为-20 dB时,基于PWVD和SPWVD方法的方向估计标准差分别为0.25°和0.28°,而基于SPW的方法只有0.04°。更多还原

【Abstract】 The performance of the DOA estimation approaches based on time-frequency analysis which have brought forward at present are not ideal for the multiple LFM signal sources situation.In this case,suppressing or eliminating cross interference terms is the key to improve direction estimation performance.This paper presents time-frequency DOA estimation based on SPW transform.The SPW combines the virtues of WVD and STFT,that is,it can suppress the cross terms quite effectively,and possesses high time-frequency aggregativeness simultaneously.This method does not need oversampling and has the prominent advantages for reducing calculation cost.Simulation results demonstrate that in multi-sources situation,the approach based on SPW improves the DOA estimation precision much more greatly compared with the approaches based on PWVD and SPWVD.For example,when the SNR is-20 dB,the root-mean-square errors of direction estimate of the approaches based on PWVD and SPWVD are 0.25°and 0.28°,respectively,while for the approach based on SPW,it is only 0.04°.更多还原