An Onboard FDMA-TDM Converter And Its Demonstration/Testing System

This thesis refers to a national project of research on satellite communication onboard processing techniques. In the project, we have succeeded in manufacturing an onboard converter from FDMA to TDM, and built up a demonstration/testing system with the converter and some special equipment self-manufactured. The thesis describes the principle, specifications and key techniques of the system, and emphases on author contributions to the project as follows:(1)Studied, in depth, on the basic theory of full-digitized QPSK modulation /demodulation, and joined some discussion about the related algorithms as well as their implementation based on digital signal processors (DSP).(2)Succeeded in designing and manufacturiiig four units for the system:a)a multi-carrier modulation (32-channel QPSK modulation) signal source based on a DSP of TMS32OC3 1.b)an IF (intermediate frequency) channel unit, composed of an amplitude modulator, twoiIF band-pass filters, a noise-input port and a down converter for multi-carrier modulation signals.c) a unit of QPSK modulation /demodulation for TDM signal.d) a TDM dc-multiplexing unit based on an EPLD devices EPLD932O.