Analysis of Received pseudorandom Sequence Coded Signal

Abstract

"The major challenges of wireless communication are multiple users scheme and information security. One particular topic for secured wireless communication is the Direct Sequence spread spectrum transmissions. The Direct sequence spread spectrum transmissions were initially developed for military applications, but they are now widely used for secure communications, especially for code division multiple access (CDMA), or global positioning systems (GPS). Spread spectrum signals are useful for secure communication for several decades, because the receiver has to know the sequence used by the transmitter to recover the transmitter data. In general, DS-SS transmitters use a periodical pseudo-random sequence to modulate the baseband signal before transmission. A receiver that does not know the sequence cannot demodulate the signal.

This report summarizes the design and implementation of direct sequence spread spectrum communications model using pseudorandom sequence. The following technology will be used and discussed for this project: Direct sequence spread spectrum system; pseudorandom sequence in time and frequency domain; How to generate the pseudorandom sequence and so on. The main software technology that applied for simulation and model is MATLAB. "