Abstract
The problems of blind timing acquisition and channel estimation for DS-CDMA signals in multipath fading channels are investigated. Using only the spreading code of the desired user, methods based on QR decompositions are proposed. These methods perform comparably or even better than subspace based methods with an order lower complexity. Furthermore, the methods exhibit significantly more robustness to channel order mismatch. Based on the acquired timing information, channel estimation algorithms are also developed which are competitive with the previously proposed subspace based channel estimation algorithms. In addition, a channel order estimation algorithm is proposed for the scenario where the order is unknown. Performance of the proposed algorithms is evaluated through simulation and comparison to asymptotic Cramér-Rao bounds.
Similar content being viewed by others
References
J.G. Proakis, Digital Communications, 3rd edn., New York: McGraw-Hill, 1995, Ch. 14, pp. 795-797.
T. Rappaport, S. Seidel, and R. Singh, “900-MHz Multipath Propagation Measurements for U.S. Digital Cellular Radiotelephone,” IEEE Transactions on Vehical Technology, vol. 39, May 1990, pp. 132-139.
E. Aktas and U. Mitra, “Single User Sparse Channel Acquisition for DS/CDMA,” submitted to the IEEE Transactions on Communication, June 2000.
S.E. Bensley and B. Aazhang, “Subspace-Based Channel Estimation for Code Division Multiple Access Communication Systems,” IEEE Transactions on Communications, vol. 44,no. 8, Aug. 1996, pp. 1009-1020.
M. Torlak and G. Xu, “Blind Multiuser Channel Estimation in Asynchronous CDMA Systems,” IEEE Transactions on Signal Processing, vol. 45,no. 1, Jan. 1997, pp. 137-147.
M.K. Tsatsanis and Z. (Daniel) Xu, “Performance Analysis of Minimum Variance CDMA Receivers,” IEEE Transactions on Signal Processing, vol. 46,no. 11, Nov. 1998, pp. 3014-3022.
M. Honig, U. Madhow, and S. Verdú, “Blind Multiuser Detection,” IEEE Trans. Inform. Theory, vol. 41,no. 7, July 1995, pp. 944-960.
X. Wang and H.V. Poor, “Blind Equalization and Multiuser Detection in Dispersive CDMA Channels,” IEEE Transactions on Communications, vol. 46,no. 1, Jan. 1998, pp. 91-103.
X. Wang and H.V. Poor, “Blind Multiuser Detection: A Subspace Approach,” IEEE Transactions on Information Theory, vol. 44,no. 2, March 1998, pp. 677-690.
I. Sharfer and A.O. Hero, “A Maximum Likelihood Digital Receiver Using Coordinate Ascent and the Discrete Wavelet Transform,” IEEE Transactions on Signal Processing, vol. 47,no. 3, March 1999, pp. 813-825.
E.G. Ström, S. Parkvall, S.L. Miller, and B.E. Ottersten, “Propagation Delay Estimation in Asynchronous Direct-Sequence Code-Division Multiple Access systems,” IEEE Transactions on Communications, vol. 44,no. 1, Jan. 1996, pp. 84-93.
U. Madhow, “Blind Adaptive Interference Suppression for the Near-far Resistant Acquisition and Demodulation of Direct-sequence CDMA Signals,” IEEE Transactions on Signal Processing, vol. 45,no. 1, Jan. 1997, pp. 124-136.
E. Ertin, U. Mitra, and S. Siwamogsatham, “Maximum-Likelihood Based Multipath Channel Estimation for Code-Division Multiple-Access Systems,” IEEE Transactions on Communications, vol. 49,no. 2, February 2001, pp. 290-302.
E.M. Dowling, L.P. Ammann, and R.D. DeGroat, “A TQR-Iteration Based Adaptive SVD for Real Time Angle and Frequency Tracking,” IEEE Transactions on Signal Processing, vol. 42,no. 4, April 1994, pp. 914-926.
C.H. Bischof and G.M. Shroff, “On Updating Signal Subspaces,” IEEE Transactions on Signal Processing, vol. 40,no. 1, Jan. 1992, pp. 96-105.
X. Li and H. (Howard) Fan, “QR Factorization Based Blind Channel Identification and Equalization with Second-Order Statistics,” IEEE Transactions on Signal Processing, vol. 48,no. 1, Jan. 2000, pp. 60-69.
L. Tong, G. Xu, and T. Kailath, “Blind Identification and Equalization Based on Second-Order-Statistics: A Time Domain Approach,” IEEE Transactions on Information Theory, vol. 40, March 1994, pp. 340-349.
G.H. Golub and C.F. Van Loan, Matrix Computations, 3rd edn., Baltimore, MD, The Johns Hopkins University Press, 1996.
J. Rissanen, “Modeling By Shortest Data Description,” in Proceedings of IFAC, 1978, pp. 465-471.
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
Pi, Z., Mitra, U. On Blind Timing Acquisition and Channel Estimation for Wideband Multiuser DS-CDMA Systems. The Journal of VLSI Signal Processing-Systems for Signal, Image, and Video Technology 30, 127–142 (2002). https://doi.org/10.1023/A:1014098825808
Published:
Issue Date:
DOI: https://doi.org/10.1023/A:1014098825808