In this paper, an iterative algorithm for multipath channel estimation is proposed for the downlink of the WCDMA systems. The estimation is performed by extracting the parameters of the channel impulse response. The channel impulse response is obtained by cross-correlation between the pilot symbols known at the receiver and the portion of the received signal which hold emitted pilot symbols. Channel estimation errors, and more particulary the false-path detection, damages the performances of coherent receiver. To avoid the false-path detection, we introduce a novel criterion which depend on signal-to-noise ratio and crosscorrelation imperfections. The simulation results reveal optimum thresholds to have a better channel estimation.