Joint channel, doppler shift and time-delay estimation for spread-spectrum communications
R.A. Iltis · 1989
A'digital spread-spectrum receiver design is presented for communication over multipath channels with aevere doppler shifts. The receiver considered uses a digital coherent RAKE combiner, coupled with an extended Kalman filter (EKF) based estimator for channel parameters and pseudo-noise .(PN) code delay. Receiver performance is evaluated by computing average bit-error rate (BER) ersus iterations of the EKF joint estimator, using both fixed and time-varying channels. It is shown that the BER obtained using the EKF joint estimator closely tracks the op timum BER obtained when the channel, delay and doppler parameters are known exactly.