A Review Comparison of different Spreading Codes for DS CDMA

In CDMA based systems; the selection of the spreading codes used for multiplexing multiple users’ data places a pivotal role. Some of the known classes of spreading codes used in CDMA-based cellular system are Walsh-Hadamard, Gold codes and Kasami codes. In this paper, presents a comparative study of different properties of these codes with the multi-level codes based on gray and inverse-gray codes In a cellular system, due to multi-path propagation channel, the orthogonality among the codes in the received CDMA signal is destroyed. To characterize this we define metrics based on all delayed auto-correlation and cross-correlation of the codes in a family. Mean Square Aperiodic Auto-Correlation (MSAAC), Mean Square Aperiodic Cross-Correlation (MSACC) measures and the Merit Factor (MF). These metrics for the GIG codes as designed and proposed in [1] were also evaluated and found to be better than other code family.