Multicode chip-interleaved DS-CDMA to effect synchronous correlation of spreading codes in quasi-synchronous transmission over multipath channels

The performance of conventional DS-CDMA systems is greatly affected by asynchronous or multipath propagation. We show that, with a certain way of multicode assignment, chip-interleaved DS-CDMA (CIDS-CDMA) can perform better in such a condition thanks to its ability to preserve the synchronous correlations among the spreading codes. Compared to the recently proposed chip-interleaved block-spread CDMA (CIBS-CDMA) that requires a single-user equalizer, the presented scheme can attain better or comparable performance in channel-coded transmission with a rake receiver that has lower complexity