Time-varying multiuser detection for DS-CDMA in doubly-selective channels

Abstract

The problem of multiuser detection for DS-CDMA in doubly-selective (timeand frequency-selective) channels is considered, and a time-varying multiuser detector (TV-MUD) to solve this problem is proposed. Using a basis expansion model (BEM) to model the doubly-selective channel and the TV-MUD, we derive a closed-form expression for the BEM coefficients of the TV-MUD as a function of the BEM coefficients of the doubly-selective channel. The criterion we use is the symbol mean-square error.