单Chirp脉冲时域自适应波束形成和参数估计

Time-domain adaptive beamforming and parameters estimation on single Chirp pulses

将最小方差无畸变响应(minimum variance distortionless response,MVDR)自适应波束形成方法拓展到一类非平稳脉冲信号,利用时域MVDR(time-domain MVDR,TMVDR)实现了单Chirp脉冲信号的自适应波束形成,即CTMVDR(TMVDR on single Chirp pulse signal,CTMVDR)。CTMVDR可估计具有常数幅值的未知Chirp脉冲信号的波达方向(direction of arrival,DOA)、信号功率和时间波形。理论分析结果表明,稳定估计自适应权向量的条件是稳定估计Chirp脉冲时间序列的自相关。数值仿真和海上实验结果表明,在采样频率不大于10倍Nyquist频率条件下,只需少于1 024个采样点,即可获得稳定的自适应权向量估计;和常规波束形成对比,CTMVDR有更好的波束响应、DOA估计、阵处理增益和Chirp脉冲信号的时间波形估计性能。

The application of minimum variance distortionless response （MVDR） adaptive beamforming is extended into one kind of non-stationary pulse signals. Using the time-domain MVDR （TMVDR）, TMVDR on single Chirp pulse signal （CTMVDR） is realized. The CTMVDR can esimate the direction of arriving （DOA）, the signal power and the time wavefome of unknown Chirp pulse signals with the constant amplitude. Theoreti- cal anylysis shows that the condition of stable estimation of weight vector is stable estimation of self-correlation of Chirp signal sequence. The results of numerical simulation and marine experiment show that the stable esti mation of the weight vector can be obtained using less than 1 024 sampling points when the sampling rate is less than 10 times nyquist frequency. Comparing with the conventional beamforming, the CTMVDR has a better performance in the estimation of beamforming response, estamation of DOA, array gain and the fidelity of waveform of Chirp pulse signals.