Code division multiple access (CDMA) techniques have attracted considerable attention for the 2nd and 3rd generations of mobile communication systems i.e. IS’95, UMTS, WCDMA and also foreseen for the 5G and beyond systems (coded OFDM). CDMA is a technology for signal transmission in telecommunication systems. In this technology, multiple users can transmit the data simultaneously in a channel using the same frequency.
Depending upon the system requirement, here in this work, the basic theory of direct sequence spread spectrum systems with special emphasis on spreading codes will be presented.
Gold code sequences are generated using MATLAB including the analysis of correlation properties with plotted figures.
Transmitted data is generated randomly using MATLAB function; the BER vs. SNR have been calculated and compared the simulated and theoretical bit error probability for one user and multiple users in the CDMA technique of Binary Phase Shift Keying (BPSK) modulation over the Additive White Gaussian Noise (AWGN) channel.
In addition, a hardware Gold code generator was implemented using KiCad, and the measurement was for one of the CDMA application which is GPS satellite system by using FPGA board.
Theoretical and simulative investigations of different receiver algorithms with special emphasis on multi-user detection Serial Interference Cancelling (SIC) and Parallel Interference Cancelling (PIC) receiver structures.
MATLAB simulation environment for simultaneous signal transmission of multiple users in (AWGN) channel applying BPSK-DS/ CDMA techniques with SIC and PIC receivers was executed.