Space-time joint truncated multistage Wiener filtering for asynchronous DS-CDMA in multipath

A novel self-synchronizing receiver with a J-element antenna array is developed for asynchronous DS-CDMA multipath fading channels in this paper. The primary requirement is knowledge of the desired user's signature sequence. There no training period of signal-free observations is required. Also no information is presumed about the interfering users. Multipath diversity is exploited via two combining schemes, namely the maximal ratio combining (MRC) and the equal gain combining (EGC). A computationally efficient receiver is developed that utilizes the concept of the truncated multistage Wiener filter (TMWF) introduced by Goldstein and Reed. This technique obviates the necessity of either a covariance matrix inversion or an eigen-decomposition. Moreover, this multistage scheme achieves a rapid adaptive convergence under limited observation-data support. Simulation results indicate that the proposed detector provides superior performance as an increasing function of the size of the J-element antenna array and is nearly independent on the number of signals.