Iterative Receiver for DS-CDMA Systems in the Presence of Time-Varying Channels
In this paper we present an efficient iterative receiver structure of tractable complexity for joint multiuser detection and multichannel estimation (JDE) of direct-sequence code-division multiple-access systems operating in the presence of time-varying flat fading channel. The time-varying channel is assumed to be modeled according to a piece-wise constant channel. An optimality criterion is defined and analytical expressions for the corresponding optimized weight coefficients are given. Monte-Carlo simulations of a synchronous scenario show that the proposed JDE receiver have excellent multiuser efficiency and are robust against errors in the estimation of the channel parameters.