DESIGN AND IMPLEMENTATION OF CDMA WIRELESS NETWORK CARD USING FPGA

Systems and Computer Engineering Department ,Al-Azhar University, Cairo, Egypt.

This paper presents a real-time digital acoustic Communication system using Code Division

Multiple Access (CDMA) technology. The proposed design is working reliably in a multipath

environment and allows for different coding gain to illustrate the trade-off between data

rate and robustness to interference. The system constructed so that the information of arbitrary

length can be sent. The user has the option to choose what Pseudo-Noise (PN) -sequence

length to use, i.e. 8, 16 or 32 when transmitting. The sort of information that is to be

transmitted can vary. A reliable prototype of the proposed CDMA communication system has

been done using the MATLAB program tools. The problems such as packing of the data, PNsequence

length, Synchronization, and equalization were encountered and solved. The

proposed system is able to transmit information from one PC to another through an entirely

acoustic channel. The problem of multi-path propagation and frequency offset was dealt with

using an adaptive equalizer. The system has been implemented by using field programmable

gate arrays (FPGAs), Xilinx XC4005X chip for the easiest of manufacturing and

reconfiguration.