Interleaving for outer convolutional codes in DS-CDMA systems

The paper deals with coding for direct-sequence code-division multiple-access (DS-CDMA) channels. A novel method for interleaver design is introduced which significantly improves the probability of error on Gaussian multiple-access channels. It is theoretically shown for a certain kind of interleaving and finite code length that almost the complete influence of interuser interference can be eliminated. Hence, the performance of a coded DS-CDMA system comes close to transmission without interuser interference. Simulations are used to confirm the analysis.