Spread Spectrum System Direct Sequence SSS

A major issue of concern in the study of digital communication is to provide a form of secure and interference free communication system in a hostile environment. This requirement is catered by a class of signaling techniques known as SPREAD SPECTRUM MODULATION. In this technique the transmitted signal spectrum is spread over a frequency range much greater than the message bandwidth . The spectrum is accomplished before the transmission through the use of code that is independent of data sequence. The same code is used in the receiver (operating synchronously with the transmitter) to de-spread the received signal so that the original message is recovered.