Multirate 3rd Generation CDMA Systems

摘要

An implementation technique for a CDMA multirate radio interface is presented. It is based on Low Rate Orthogonal Convolutional (LOROC) coding initially introduced by Viterbi [7]. A connection between LOROC encoding and the multiuser equalization structures of [4] is established and it is shown that the combined scheme is a strong candidate for implementing third generation digital cellular systems capable of supporting multimedia services. In the first part the LOROC encoding scheme is reviewed with emphasis on the Multiple Access Interference characterisation of LOROC encoded multirate spread spectrum signals. The effect of interleaving is also addressed. In the second part, a multiuser equalizer particular suitable for a MAI rejecting mobile hand-portable is put together with a LOROC decoder. The implementation aspects and dvantages of this combination are also addressed.