SAGE algorithms for multipath detection and parameter estimation in asynchronous CDMA systems

Algorithms to estimate blindly the parameters and input sequences for a mul tiuser asynchronous code division multiple access (CDMA) system are propose d, The communication system is modeled as a frequency selective fading chan nel with multipath propagation, where the number of active propagation chan nels is unknown and highly time varying, Estimates of input sequences and u nknown parameters are jointly computed via the SAGE algorithm, The SAGE alg orithm provides a unified approach in combining jointly multiuser detection and parameter estimation in an optimal way. Depending on the realizations of the SAGE algorithm, well-known state and parameter estimation schemes of various complexities are optimally combined.