Digital Communications 2

5Study of Baseband Digital Transmission Systems for the Transmission of Analog Signals (Transmitter and Receiver)

5.1. Objectives

The goals of this lab work are to study the various functions necessary for serial transmission under digital form of analog signals. These are distributed in the transmitter on the one hand, and in the receiver on the other hand. Although most of them are present simultaneously in both of them, the receiver has some additional specific functions.

The study will largely be of a qualitative nature but will also include some measures allowing a quantitative assessment of the influence of certain parameters.

This study first deals with a pulse amplitude modulation transmission system with time division multiplexing. Then, the operation of a pulse code modulation (PCM) transmission system is analyzed. For these two systems, we will study in particular the two mechanisms of recovering the frame synchronization and the clock without additional links between transmitter and receiver other than that of transmission of the on-line code. In addition, for PCM transmission, codes for protection against transmission errors (error detection code, error detection and error correction code) are also used.

5.2. First part – Study of a pulse amplitude modulation and time division multiplex signal transmission system

A MODICOM2 educational electronic board from the company LJ Technical Systems (the reader must simply see the block diagram on the board) is at your ...