Implementation of digital modulation techniques using direct digital synthesis

Abstract

In the past decade, low earth orbit satellite systems have become increasingly popular. There is a growing need for hardware and software to model emerging low earth orbit satellite systems. One possible implementation of the transmitter for a low earth orbit satellite system is with direct digital synthesis equipment. Here we build hardware compatible with the IBM PC and software in ' C ' to simulate a low earth satellite transmitter using a direct digital synthesis system. We present a detailed working analysis of the direct digital synthesis system. The analysis shows the biggest advantage of the direct digital synthesis method is its very fine frequency and phase resolution with the disadvantages being its cost and frequency limitation.