Sparse channel estimation and tracking for cyclic delay diversity orthogonal frequency division multiplexing systems. Issue 18 (15th November 2011)

• Record Type: Journal Article
• Authors: Hou, Weikun; Wang, Xianbin
• Is Part Of: Wireless communications and mobile computing. Volume 13:Issue 18(2013)
• Page Start: 1635
• Page End: 1647
• Publication Date: 2011-11-15
• Subjects: Wireless communication systems -- Periodicals; Mobile communication systems -- Periodicals; 621.38205
• DOI: 10.1002/wcm.1208
• Languages: English
• ISSNs: 1530-8669

Abstract

<abstract abstract-type="main" id="wcm1208-abs-0001"> <title>ABSTRACT</title> <p id="wcm1208-para-0003">In cyclic delay diversity orthogonal frequency division multiplexing systems, the excessive channel delay spread and corresponding high frequency selectivity makes channel estimation a challenging task. In this paper, we propose a two‐stage scheme to estimate and track the highly frequency selective channel. At the preamble reception stage, least squares channel estimation with <italic>L</italic>₀ norm regularization is proposed to exploit the channel sparsity. At the data demodulation stage, an expectation–maximization algorithm with the most significant tap selection is developed to track channel variations by using the channel order obtained from the first stage. Compared with other estimation methods, the proposed scheme requires no prerequisite knowledge of delay parameter settings, which leads to more flexibility. Furthermore, the scheme can exploit the channel sparse structure by detecting the nonzero taps and, consequently, has better mean squared error performance. Simulation results show that the proposed estimation scheme can retain the provided diversity gain of cyclic delay diversity effectively in time‐varying fading channels. Copyright © 2011 John Wiley &amp; Sons, Ltd.</p> </abstract>