Implementation aspects of linear multiuser detectors in asynchronous CDMA systems

Several linear multiuser detectors for code-division multiple-access (CDMA) systems can be characterized as an inverse of some form of correlation matrices. If the correlations change, the detectors must be updated. Efficient algorithms for updating multiuser detectors in asynchronous CDMA systems are considered. Computation algorithms of the decorrelating, the LMMSE, and the noise-whitening detectors based on an order-recursive Cholesky factorization are presented and their computational complexity is analyzed. The algorithmic complexity is studied in a mobile communication example.