- Research Article
- Open Access
Frequency-Shift Zero-Forcing Time-Varying Equalization for Doubly Selective SIMO Channels
EURASIP Journal on Advances in Signal Processing volume 2006, Article number: 047261 (2006)
This paper deals with the problem of designing linear time-varying (LTV) finite-impulse response zero-forcing (ZF) equalizers for time- and frequency-selective (so-called doubly selective) single-input multiple-output (SIMO) channels. Specifically, relying on a basis expansion model (BEM) of the rapidly time-varying channel impulse response, we derive the canonical frequency-domain representation of the minimal norm LTV-ZF equalizer, which allows one to implement it as a parallel bank of linear time-invariant filters having, as input signals, different frequency-shift (FRESH) versions of the received data. Moreover, on the basis of this FRESH representation, we propose a simple and effective low-complexity version of the minimal norm LTV-ZF equalizer and we discuss the relationships between the devised FRESH equalizers and a LTV-ZF equalizer recently proposed in the literature. The performance analysis, carried out by means of computer simulations, shows that the proposed FRESH-LTV-ZF equalizers significantly outperform their competitive alternative.
Giannakis GB, Tepedelenlioğlu C: Basis expansion models and diversity techniques for blind identification and equalization of time-varying channels. Proceedings of the IEEE 1998, 86(10):1969–1986. 10.1109/5.720248
Tsatsanis MK, Giannakis GB: Modeling and equalizing of rapidly fading channels. International Journal of Adaptive Control and Signal Processing 1998, 159–176.
Sayeed AM, Aazhang B: Joint multipath-doppler diversity in mobile wireless communications. IEEE Transactions on Communications 1999, 47(1):123–132. 10.1109/26.747819
Ma X, Giannakis GB: Maximum-diversity transmissions over doubly selective wireless channels. IEEE Transactions on Information Theory 2003, 49(7):1832–1840. 10.1109/TIT.2003.813485
Leus G, Zhou S, Giannakis GB: Orthogonal multiple access over time- and frequency-selective channels. IEEE Transactions on Information Theory 2003, 49(8):1942–1950. 10.1109/TIT.2003.814477
Leus G, Barhumi I, Moonen M: Low-complexity serial equalization of doubly-selective channels. In Proceedings of the 6th Baiona Workshop on Signal Processing in Communications, September 2003. Baiona, Spain; 69–74.
Tepedelenlioğlu C, Giannakis GB: Transmitter redundancy for blind estimation and equalization of time- and frequency-selective channels. IEEE Transactions on Signal Processing 2000, 48(7):2029–2043. 10.1109/78.847788
Jakes WC: Microwave Mobile Channels. John Wiley & Sons, New York, NY, USA; 1974.
Barhumi I, Leus G, Moonen M: Time-varying FIR equalization for doubly selective channels. IEEE Transactions on Wireless Communications 2005, 4(1):202–214.
Tugnait JK, Luo W: Linear prediction error method for blind identification of periodically time-varying channels. IEEE Transactions on Signal Processing 2002, 50(12):3070–3082. 10.1109/TSP.2002.805493
Franks L: Polyperiodic linear filtering. In Cyclostationarity in Communications and Signal Processing. Edited by: Gardner WA. IEEE Press, Piscataway, NJ, USA; 1994:240–266.
Ben-Israel A, Greville TNE: Generalized Inverses. Springer, New York, NY, USA; 2002.
Bello PA: Characterization of randomly time-variant channels. IEEE Transactions on Communications 1963, 11(4):360–393. 10.1109/TCOM.1963.1088793
Tugnait JK, Luo W: Blind identification of time-varying channels using multistep linear predictors. IEEE Transactions on Signal Processing 2004, 52(6):1739–1749. 10.1109/TSP.2004.827174
Luo W, Tugnait JK: Semi-blind time-varying channel estimation using superimposed training. Proceedings of International Conference on Acoustics, Speech, and Signal Processing (ICASSP '04), May 2004, Montreal, Canada 797–800.
Leus G: On the estimation of rapidly time-varying channels. Proceedings of the European Signal Processing Conference, September 2004, Vienna, Austria 120–123.
Proakis JG: Digital Communications. McGraw-Hill, New York, NY, USA; 2001.
Tong L, Perreau S: Multichannel blind identification: from subspace to maximum likelihood methods. Proceeedings of the IEEE 1998, 86(10):1951–1968. 10.1109/5.720247
Horn RA, Johnson CR: Matrix Analysis. Cambridge University Press, Cambridge, UK; 1990.
Vescovo R: Inversion of block-circulant matrices and circular array approach. IEEE Transactions on Antennas and Propagation 1997, 45(10):1565–1567. 10.1109/8.633869
Björck A: Numerical Methods for Least Squares Problems. SIAM, Philadelphia, Pa, USA; 1996.
Serpedin E, Giannakis GB: A simple proof of a known blind channel identifiability result. IEEE Transactions on Signal Processing 1999, 47(2):591–593. 10.1109/78.740150
Honig M, Madhow U, Verdù S: Blind adaptive multiuser detection. IEEE Transactions on Information Theory 1995, 41(4):944–960. 10.1109/18.391241