If Pcm / Dpsk Telemetry Signal Full Softening Demodulation Technology

At ground receiving station, magnetic tape was generally used to record the undetectable signal. With the development of the technologies of high-speed sampling and large capacity disk array recording, sampling at intermediate frequency and digital recording can be adopted. There are two merits of digital recording: One is avoiding the lost of SNR when analog recording; the other is digital recorded signal can be directly sent to PC to be demodulated by software afterwards. In this paper, the software demodulation realizes the demodulation by software and outputs the code stream.Based on the introduction of the software demodulation's advantage, the theory of PCM/DPSK telemetry signal's software demodulation is presented. The designation and the deduction of its arithmetic are accomplished. The realization of DDC, cascaded filter and decimation, timing-error decimation, bit synchronization and difference detection by software are all introduced in this paper. Satisfied result is achieved through computer simulation and experimentation. This research effort gives the preparation for going deeper into the research in future.