Design and implementation of an EKF-based tracking synchronism scheme for an indoor DS/CDMA system

In a direct-sequence code-division multiple-access (DS-CDMA) system, code synchronisation is essential for the demodulation of the received signals from different users. In this paper, we propose two different structures based on the extended Kalman filter (EKF) for code synchronization by means of channel delay estimation. Performance of both schemes in terms of the normalised error jitter and the mean-time to lose-lock (MTLL) are shown through results obtained via extensive computer simulations under indoor mobile channel conditions. These results have also been validated by implementing a DSP-based DS/CDMA system demonstrator built for this purpose.