Joint estimation of time delay and channel amplitude by simplex unscented filter without assisted pilot in CDMA systems

In mobile communications, to overcome the highly nonlinear nature of time delay estimation, an iterative nonlinear filtering algorithm, called the scaled unscented filter (SUF) has recently been proposed in the field of nonlinear filter theory. Furthermore a newly introduced method, called simplex unscented filter (SimplexUF) uses significantly fewer points than other unscented filter methods previously published, while showing comparable performance (accuracy) of mean and covariance to SUF. In this paper we apply a SimplexUF-based algorithm for the estimation of closely-spaced path delays and related coefficients in CDMA environments. The simulation results also show that this filter performs as good as SUF. We also show that it provides a more viable means for tracking error for time-varying amplitudes and delays in CDMA communication systems than SUF