Blind Channel Estimation for Space-Time Coded WCDMA

A new blind channel estimation technique is proposed for space-time coded wideband CDMA systems using aperiodic and possibly multirate spreading codes. Using a decorrelating front end, the received signal is projected onto subspaces from which channel parameters can be estimated up to a rotational ambiguity. Exploiting the subspace structure of the WCDMA signaling and the orthogonality of the unitary spacetime codes, the proposed algorithm provides the least squares channel estimate in closed form. A new identifiability condition is established. The mean square error of the estimated channel is compared with the Cramer-Rao bound, and a bit error rate (BER) performance for the proposed algorithm is compared with di#erential schemes

EURASIP Journal on Wireless Communications and Networking 2004:2, 322–334 c ○ 2004 Hindawi Publishing Corporation Blind Channel Estimation for Space-Time Coded WCDMA

A new blind channel estimation technique is proposed for space-time coded wideband CDMA systems using aperiodic and possibly multirate spreading codes. Using a decorrelating front end, the received signal is projected onto a subspace from which channel parameters can be estimated up to a rotational ambiguity. Exploiting the subspace structure of the WCDMA signaling and the orthogonality of the unitary space-time codes, the proposed algorithm provides a blind channel estimate via least squares. A new identifiability condition is established under the assumption that the system is not heavily loaded. The mean square error of the estimated channel is compared with the Cramér-Rao bound, and the bit error rate (BER) performance of the proposed algorithm is compared with that of differential schemes