Analysis of different Pseudo-Random and orthogonal spreading sequences in DS-CDMA

Pseudo-Random or pseudo-noise and Orthogonal Spreading sequences are widely used in the Wideband Code Division Multiple Access (WCDMA) systems using Rake receiver. This paper shows the theoretical aspect for direct sequences DS-CDMA systems and reviews the main characteristics of the maximal length, Gold, barker and Kasami sequences, also the variable and fixed-length orthogonal codes are discussed. Finally, comparisons between these methods is given by using autocorrelation, cross-correlation functions, The mean square aperiodic auto-correlation (MSAAC), the mean square aperiodic cross-correlation (MSACC) measures and the Merit factor (MF).