Fast Blind Adaptive Channel Shortening Using Signal Subspace

• Published in: VTC Spring 2008 - IEEE Vehicular Technology Conference pp. 2621 - 2625
• Main Authors: Karami, M., Olfat, A.
• Format: Conference Proceeding
• Language: English
• Published: IEEE 01-05-2008
• Subjects: Adaptive signal processing; Delay systems; Eigenvalues and eigenfunctions; Equalizers; Finite impulse response filter; Laboratories; Nonlinear filters; OFDM; Signal processing; Signal processing algorithms
• ISBN: 1424416442; 9781424416448
• ISSN: 1550-2252
• DOI: 10.1109/VETECS.2008.575

In cyclic-prefixed communication systems, if the delay spread of the channel is longer than the cyclic prefix (CP) a channel-shortening equalizer (CSE) can be used to restore the desired operation of such systems. Since in time-varying environment we are interested in fast adaptive equalizer with tracking capability, the aim of this paper is to propose RLS-type algorithm for channel shortening. In this paper, we first propose an RLS-type algorithm to estimate the eigenvector corresponding to the smallest eigenvalue of a matrix and based on this algorithm we develop an RLS-type blind channel shortener. We also, based on PAST algorithm, propose an RLS-type update rule to shorten the channel under MMSE criterion. Simulations show the speed advantage of the proposed algorithms.