A subspace blind adaptive multiuser detection scheme over multipath channel using Kalman filter

Blind multiuser detection in CDMA systems is considered in this paper. A new blind adaptive multiuser detection scheme, based on a hybrid of Kalman filter and subspace estimation, is proposed. It is shown that the detector can be expressed as an anchored signal in the signal subspace and the coefficients can be estimated by the Kalman filter using only the signature waveform and the timing of the desired user. The convergence performance in flat fading and multipath fading channels is studied by numerical simulation. It is concluded that the proposed scheme has lower computational complexity, improved convergence performance and is more robust in the presence of signature waveform mismatch.