Frequency-domain Differential Detection and Equalization for 2-dimensional spread/chip-interleaved DS-CDMA

摘要

The multiple-access interference (MAI) limits the performance of the DS-CDMA uplink transmission. 2D OVSF spread/chip-interleaved DS-CDMA is an MAI-free system, and hence single-user coherent frequency-domain equalization (FDE) can be used instead of complicated multiuser detection (MUD). However, coherent FDE needs channel estimation. Pilot-assisted channel estimation is not reliable when Doppler fading is fast. In this paper, we consider frequency-domain differential detection and equalization (FDDDE) in a multiuser/multipath environment, which doesn't require channel estimation and is robust against fast fading. The transmission performance of 2D spread/chip-interleaved DS-CDMA using FDDDE in a time- and frequency-selective fading multiuser environment is evaluated by computer simulation.