PCM/FM遥测中频数字化接收机设计与实现

Design and Implementation of PCM/FM Telemetry IF Digitized Receiver

本文利用高速高精度数据采集、数字下变频DDC(Digital Downconversion)CORDIC(Coordinate RotationDigital Computer)数字鉴相、一阶差分鉴频和均匀采样二阶数字锁相环DPLL(Digital Phage—Locked Loop)去除多谱勒频率和载波频偏等技术完成了2MHz码速率10.7MHz中频频率的PCM/FM遥测中频数字化接收机设计,并给出了实现系统接收线性动态范围和不同输入信噪比条件输出信号波形的测试结果。测试结果表明,设计系统的接收线性动态范围可达50dB以上,而在输入信噪比≤7dB的情况下设计系统还可以正常工作。

Design of PCM/FM Telemetry IF Digitized Receiver with 2MHz code rates and 10.7MHz IF frequency are completed using high-speed and high-precision data acquisition, digital downconversion, CORDIC digital phase discrimination, first-order differential frequency discrimination and uniform sampling second-order DPLL. The receiving linear dynamic range and test results of output signal waveforms under different input SNR (signal-to-noise rate) conditions are given. Test results indicate that receiving linear dynamic range of the system is larger than 50dB and the system can still work well under input SNR≤7dB.