Receiver architectures for the down-link in a DS-CDMA mobile system

Some receiver architectures for the down-link in a DS-CDMA (direct sequence-code division multiple access) mobile communications system are here outlined. The performance relevant to a three-arms RAKE receiver, with a refined multipath tracking structure, is compared with that obtained by a less sophisticated RAKE receiver and, for reference purposes, with that of a classical receiver synchronized on the strongest path. The receiver makes use of a pilot signal transmitted by the base station for synchronization and channel equalization purposes. The effects of the multipath tracking algorithm and the sensitivity to some parameters of paramount importance (pilot to useful signal power ratio, mobile speed, quantization) have been simulated under multipath fading propagation conditions. The results of such simulations are presented as well as some indications about a design of a receiver based on the above structure