Blind Channel Estimation for Frequency Hopping System Using Subspace Based Method

Subspace channel estimation methods have been
studied widely, where the subspace of the covariance matrix is
decomposed to separate the signal subspace from noise subspace. The
decomposition is normally done by using either the eigenvalue
decomposition (EVD) or the singular value decomposition (SVD) of
the auto-correlation matrix (ACM). However, the subspace
decomposition process is computationally expensive. This paper
considers the estimation of the multipath slow frequency hopping
(FH) channel using noise space based method. In particular, an
efficient method is proposed to estimate the multipath time delays by
applying multiple signal classification (MUSIC) algorithm which is
based on the null space extracted by the rank revealing LU (RRLU)
factorization. As a result, precise information is provided by the
RRLU about the numerical null space and the rank, (i.e., important
tool in linear algebra). The simulation results demonstrate the
effectiveness of the proposed novel method by approximately
decreasing the computational complexity to the half as compared
with RRQR methods keeping the same performance.

• M. M. Qasaymeh
• M. A. Khodeir

• Time Delay Estimation
• RRLU
• RRQR
• MUSIC
• LS-ESPRIT
• LS-ESPRIT
• Frequency Hopping.

[1] R. L. Pickholtz et al., “Theory of spread spectrum communications – a
tutorial,” IEEE Trans. Commun., Vol. COM-30, pp. 855–884, May
1982.
[2] X.Wang and Z. Kostic, “Analysis of frequency-hopped cellular systems
with dynamic FH pattern adaptation,” in Proc. IEEE Globecom, Comm.
Theory Mini Conf., Sydney, Australia, Nov. 1998.
[3] P.H. Hande, L. Tong, and A. Swami, "Channel Estimation for Frequency
Hopping Systems," in MILCOM 99, Nov. 1999
[4] Prashanth Hande, Lang Tong, and Ananthram Swami “Flat Fading
Approximation Error” IEEE Commumications Letteres, Vol. 4, No. 10,
October 2000.
[5] J. Marot, C. Fossati and S. Bourennane, “Fast subspace-based source
localization methods”, Sensor Array and Multichannel Signal Processing
Workshop, 2008. SAM 2008. 5th IEEE, (2008) July 21-23, pp. 203-206.
[6] R. Roy, A.Paulraj, and T. Kailath. “ESPRIT – A subspace rotation
approach to estimation of parameters of cisoids in noise”. IEEE trans. on
acoustics and speech signal proc,ASSP-34(10): 1340-1342, October,
1986.
[7] P. Hande, L. Tong and A. Swami "Multipath Delay Estimation for
Frequency Hopping Systems" J. VLSI Signal Processing, Vol. 30, pp
163-178, March, 2002.
[8] P.H. Hande, L. Tong, and A. Swami, "Channel Estimation for Frequency
Hopping Systems via Multiple Invariances," in Proc. IEEE Wireless
Comm. and Networking Conf., Sept. 2000.
[9] C. H. Bischof and G. Quintana-orti’, “Computing rank-revealing QR
factorizations of dense matrices” ACM Transactions on Mathematical
Software (TOMS), Vol. 24, issue 2, pp 226-253, 1998
[10] M. Qassymeh, et al., “Time Delay Estimator for Frequency Hopping
System using Rank-Revealing Triangular Factorization,” the
Proceedings of IEEE Vehicular Technology Conference, Barcelona,
Spain, April 2009.
[11] Hayes, “Statistical Digital Signal Processing” Wiley 1996.