We present a new digital direct-sequence (DS) receiver with joint estimation of code delay, multipath gains and Doppler shift. A parameter estimator consisting of a parallel bank of extended Kalman filters (EKF's) extracts estimates of the timing, τ and the multipath coefficients, f l  distorting the received signal. A «detected» estimate of the Doppler shift, υ r  distorting the received signal is also provided by the estimator. We compute the bit error rate that results when a RAKE matched filter uses the estimated parameters to detect the DPSK encoded binary data in the received signal. The bit-error rate (BER) is evaluated, and successful performance of the proposed receiver in the presence of Doppler shift distortion is observed in many cases
['Alfred W. Fuxjaeger', 'Ronald A. Iltis']
Adaptive parameter estimation using parallel Kalman filtering for spread spectrum code and Doppler tracking