基于DSP的超声波接收前端分析与优化设计

Analysis and optimal design for front-end of ultrasonic receiver system based on DSP

针对超声波微弱信号接收和处理问题,进行了基于DSP(digital signal processor)开发板的采集前端分析与优化设计。采用下变频技术,充分利用了开发板上的音频编译码器实现微弱超声波信号采集。通过与普通ADC(analog-to-digital converter)采集方案的噪声系数进行对比,表明系统在微弱信号情况下,仍然可以获得较高的信噪比。该方案应用于一种便携式的超声波接收系统,使用户随时可以进行超声波信号的接收与处理工作。

For the problem of the reception and processing of the weak ultrasonic signals ,the front‐end of acquisition module based on DSP development board is analyzed and optimized . This article realizes the acquisition of the weak signals of ultrasonic wave by adopting the technologies of downconversion and fully utilization of the audio codec module on the development board . After comparing the noise figure of the ordinary ADC acquisition module ,the SNR of this method is higher in weak signal environments .This system is proposed to be applied to a portable ultrasonic receiver system allowing users to be able to receive and process the ultrasonic signals at any time .