互相关技术中基于零阶保持器的离散冲激响应模型

A Zero-Order-Hold Based Discrete-time Impulse Response Model in the Cross-correlation Technique

利用互相关技术能有效估计线性系统的冲激响应。然而,对于基于数值计算的互相关技术,D/A和A/D转换器的使用必然会带来原理性的误差。该文利用零阶保持器(ZOH)模型从理论上分析了离散时间系统的冲激响应,即它与连续系统冲激响应之间的关系,并给出了时域解析表达式。通过该公式可以直观地把握冲激响应估计的逼真度。

The cross-correlation technique can be used to estimate the impulse response of a linear systero. However, the use of the D/ A and A/D converters inevitably causes systematic errors. A theoretical analysis of the discrete-time impulse response estimated in a sampling system is performed. The relationship between discrete-time and continuous-time impulse responses is studied, and an analytical equation is deduced based on the Zero-Order-Holder （ZOH）. With the equation, an intuitive grasp of the fidelity of the estimated impulse response to that of the real system can be obtained.