中文摘要：

超声背散射信号能提供反映组织微结构的有用信息。本文在原有的生物组织超声背散射信号仿真模型基础上，将影响平均散射元间距（MSS）估计的组织特性具体为4个主要参数，为检测各种平均散射元间距估计方法的性能提供了方便。文中用AR倒谱方法对仿真信号4个参数的合理性进行反向测试，实验结果表明，仿真信号的4个参数能表示影响平均散射元间距估计性能的组织特性。通过仿真信号与人体脾组织的背散射信号以及相关文献中组织信号的比较，证明仿真信号与具有准周期性的生物组织背散射信号基本类似。

英文摘要：

Ultrasonic backscattered signals can provide useful information about tissue microstructures. Based on an original simulation model for a backscattered signal, four main parameters are proposed to represent tissue characteristics which influence the estimation of mean scatterer spacing （MSS）. This model helps evaluate the performance of various mean scatterer spacing techniques. Autoregressive （AR） cepstrum method is used to validate the four parameters＇ rationality. The simulated results indicate that the four parameters can represent the tissue characteristics, which influence the estimation of the MSS. A comparison between simulation signals and real tissue ultrasonic backscattered signals is made to prove that simulated signals are fairly similar to the backscattered signals from quasiperiodic tissues.