System identification using chirp signals and time-variant filters in the joint time-frequency domain
System identification using chirp signals and time-variant filters in the joint time-frequency domain
复制标题
在联合时频域中使用线性调频信号和时变滤波器进行系统辨识
DOI：
10.1109/78.611210
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发表时间：
1997
期刊：
影响因子：
--
通讯作者：
X. Xia
中科院分区：
文献类型：
--
作者：
X. Xia
提出了一种在低信噪比环境下辨识未知线性时不变系统的新方法。该方法是基于发射啁啾信号的发射机和使用线性时变滤波器的联合时频（TF）域的接收机，以减少识别前的噪声。由于线性调频信号的TF局部化特性，可以减少大量的加性白色噪声，因此，可以显著提高识别前的信噪比。然而，这在使用伪随机信号的常规方法中不能实现，因此，不应用降噪技术。仿真结果表明，在低信噪比环境下，该方法的性能明显优于传统方法。本文为时频分析与综合提供了一个很好的应用。
We propose a novel method to identify an unknown linear time invariant (LTI) system in low signal-to-noise ratio (SNR) environment. The method is based on transmitting chirp signals for the transmitter and using linear time-variant filters in the joint time-frequency (TF) domain for the receiver to reduce noise before identification. Due to the TF localization property of chirp signals, a large amount of additive white noise can be reduced, and therefore, the SNR before identification can be significantly increased. This, however, cannot be achieved in the conventional methods, where pseudo-random signals are used, and therefore, noise reduction techniques do not apply. Our simulation results indicate that the method proposed outperforms the conventional methods significantly in a low SNR environment. This paper provides a good application of time-frequency analysis and synthesis.