Resolving subchip-spaced multipath components in CDMA communication systems

A method is developed for resolving channel multipath components for direct-sequence code-division multiple-access (DS-CDMA) communication systems. Components which are spaced closer than a chip interval of the DS signature sequence are separable by the presented technique. The method is based on the constrained iterative deconvolution which uses the method of projection onto convex sets (POCS). A novel POCS constraint is derived which takes advantage of the noise covariance modified by a matched filter at the front end of the receiver. Simulation results for m-sequences and BPSK modulation are presented.