Progressively powerful multiuser detectors for rapidly time-varying multipath environments

Multiaccess interference (MAI), time-varying multipath effects and receiver complexity are the most significant factors that dictate the signal processing requirements for CDMA systems. Most existing CDMA receiver designs are inadequate in jointly addressing these issues. We propose receiver design in canonical multipath-Doppler coordinates as a systematic framework for multiuser detection over time-varying multipath channels. The canonical coordinates are defined by a fixed basis derived from a fundamental characterization of multipath propagation effects. The framework provides an integrated design approach for combating time-varying multipath distortion, suppressing MAI and tailoring receiver complexity to a desired level of performance.