PCM系统中数字相敏检波器的设计与仿真

在PCM（埋地管道电流测绘）系统中，实际的信号采集需要解决在非常恶劣的环境中对ELF（甚低频）信号的精确测量的问题。传统的方法一般都采用APSD（模拟相敏检波器）来实现，然而在实际的电路中用模拟相敏检波器效果并不是很理想，结果存在严重的误差。针对目前模拟相敏检波器存在的问题，设计一种DPSD（数字相敏检波器）实现消除PCM系统中ELF信号中工频干扰的目的。该检波器能有效的克服模拟相敏检波器的缺点，更精确的进行微弱信号的检测，最后使用MATLAB仿真软件对模拟和数字相敏检波器进行了仿真比较。

The design and simulation of DPSD in PCM system

In the PCM system, the actual signal acquisition needs to solve the problem of precise measure- ment of ELF signal which is always in the very bad environment. The traditional methods typically use APSD, which results in serious error in the actual circuit. To solve the problem of APSD, this paper designs a DPSD to eliminate the noise of ELF signal in the PCM system. The detector can effectively overcome the disadvantages of APSD, and is more accurate for weak signal detection. The paper finally uses MATLAB for APSD and DPSD simulation and comparison.