Kalman-filter based chip estimator for WCDMA downlink detection

In the WCDMA downlink, the multipath channel destroys orthogonality between users and causes multiple access interference (MAI). This channel-induced MAI can be combated by channel equalization to approximately restore orthogonality. This paper presents a chip-estimator method based on Kalman filtering suitable for WCDMA downlink. The method does not require a training sequence or the knowledge of other-users´ spreading codes. Simulation results show considerable performance improvement using the proposed estimator compared with that of the RAKE receiver.