- Research Article
- Open Access
A Low-Complexity Time-Domain MMSE Channel Estimator for Space-Time/Frequency Block-Coded OFDM Systems
EURASIP Journal on Advances in Signal Processing volume 2006, Article number: 039026 (2006)
Focusing on transmit diversity orthogonal frequency-division multiplexing (OFDM) transmission through frequency-selective channels, this paper pursues a channel estimation approach in time domain for both space-frequency OFDM (SF-OFDM) and space-time OFDM (ST-OFDM) systems based on AR channel modelling. The paper proposes a computationally efficient, pilot-aided linear minimum mean-square-error (MMSE) time-domain channel estimation algorithm for OFDM systems with transmitter diversity in unknown wireless fading channels. The proposed approach employs a convenient representation of the channel impulse responses based on the Karhunen-Loeve (KL) orthogonal expansion and finds MMSE estimates of the uncorrelated KL series expansion coefficients. Based on such an expansion, no matrix inversion is required in the proposed MMSE estimator. Subsequently, optimal rank reduction is applied to obtain significant taps resulting in a smaller computational load on the proposed estimation algorithm. The performance of the proposed approach is studied through the analytical results and computer simulations. In order to explore the performance, the closed-form expression for the average symbol error rate (SER) probability is derived for the maximum ratio receive combiner (MRRC). We then consider the stochastic Cramer-Rao lower bound(CRLB) and derive the closed-form expression for the random KL coefficients, and consequently exploit the performance of the MMSE channel estimator based on the evaluation of minimum Bayesian MSE. We also analyze the effect of a modelling mismatch on the estimator performance. Simulation results confirm our theoretical analysis and illustrate that the proposed algorithms are capable of tracking fast fading and improving overall performance.
Van Nee R, Prasad R: OFDM Wireless Multimedia Communications. Artech House, London, UK; 2000.
Sari H, Karam G, Jeanclaude I: Transmission techniques for digital terrestrial TV broadcasting. IEEE Communications Magazine 1995, 33(2):100-109. 10.1109/35.350382
Yang B, Cao Z, Letaief KB: Analysis of low-complexity windowed DFT-based MMSE channel estimator for OFDM systems. IEEE Transactions on Communications 2001, 49(11):1977–1987. 10.1109/26.966074
Li Y(G), Seshadri N, Ariyavisitakul S: Channel estimation for OFDM systems with transmitter diversity in mobile wireless channels. IEEE Journal on Selected Areas in Communications 1999, 17(3):461–471. 10.1109/49.753731
Li Y(G): Simplified channel estimation for OFDM systems with multiple transmit antennas. IEEE Transactions on Wireless Communications 2002, 1(1):67–75. 10.1109/7693.975446
Lee KF, Williams DB: A space-frequency transmitter diversity technique for OFDM systems. Proceedings of IEEE Global Telecommunications Conference, November 2000, San Francisco, Calif, USA 3: 1473–1477.
Liu Z, Xin Y, Giannakis GB: Space-time-frequency coded OFDM over frequency-selective fading channels. IEEE Transactions on Signal Processing 2002, 50(10):2465–2476. 10.1109/TSP.2002.803332
Bolcskei H, Paulraj AJ: Space-frequency coded broadband OFDM systems. Proceedings of IEEE Wireless Communications and Networking Conference (WCNC '00), September 2000, Chicago, Ill, USA 1: 1–6.
Alamouti SM: A simple transmit diversity technique for wireless communications. IEEE Journal on Selected Areas in Communications 1998, 16(8):1451–1458. 10.1109/49.730453
Tarokh V, Seshadri N, Calderbank AR: Space-time codes for high data rate wireless communication: performance criterion and code construction. IEEE Transactions on Information Theory 1998, 44(2):744–765. 10.1109/18.661517
Tarokh V, Jafarkhani H, Calderbank AR: Space-time block codes from orthogonal designs. IEEE Transactions on Information Theory 1999, 45(5):1456–1467. 10.1109/18.771146
Tolochko I, Faulkner M: Real time LMMSE channel estimation for wireless OFDM systems with transmitter diversity. Proceedings of IEEE 56th Vehicular Technology Conference (VTC '02), September 2002, Vancouver, BC, Canada 3: 1555–1559.
Hou X, Xu Y, Zheng B, Luo H: A time-domain approach for channel estimation in MIMO-OFDM-based wireless networks. IEICE Transactions on Communications 2005, E88-B(1):3–9. 10.1093/ietcom/E88-B.1.3
Miao H, Juntti MJ: Data aided channel estimation for wireless MIMO-OFDM systems. In Multicarrier Spread Spectrum. Edited by: Fazel K, Kaiser S. Kluwer Academic, Boston, Mass, USA; 2004:211–218.
Yip K-W, Ng T-S: Karhunen-Loève expansion of the WSSUS channel output and its application to efficient simulation. IEEE Journal on Selected Areas in Communications 1997, 15(4):640–646. 10.1109/49.585774
Panayırcı E, Çırpan HA: Channel estimation for space-time block coded OFDM systems in the presence of multipath fading. Proceedings of IEEE Global Telecommunications Conference (GLOBECOM '02), November 2002, Taipei, Taiwan 2: 1157–1161. A17
Kay SM: Fundamentals of Statistical Signal Processing: Estimation Theory. Prentice Hall, Englewood Cliffs, NJ, USA; 1993.
Morelli M, Mengali U: A comparison of pilot-aided channel estimation methods for OFDM systems. IEEE Transactions on Signal Processing 2001, 49(12):3065–3073. 10.1109/78.969514
Van Trees HL: Detection, Estimation and Modulation Theory, Part I. Wiley Interscience, New York, NY, USA; 1993.
Edfors O, Sandell M, Van de Beek J-J, Wilson SK, Borjesson PO: OFDM channel estimation by singular value decomposition. IEEE Transactions on Communications 1998, 46(7):931–939. 10.1109/26.701321
Şenol H, Çırpan HA, Panayırcı E: A low-complexity KL-expansion based channel estimator for OFDM systems. EURASIP Journal on Wireless Communications and Networking 2005, 2005(2):163–174.
Li Y(G), Cimini LJ Jr., Sollenberger NR: Robust channel estimation for OFDM systems with rapid dispersive fading channels. IEEE Transactions on Communications 1998, 46(7):902–915. 10.1109/26.701317
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Şenol, H., Çırpan, H., Panayırcı, E. et al. A Low-Complexity Time-Domain MMSE Channel Estimator for Space-Time/Frequency Block-Coded OFDM Systems. EURASIP J. Adv. Signal Process. 2006, 039026 (2006) doi:10.1155/ASP/2006/39026
- Channel Estimation
- Channel Impulse Response
- OFDM System
- Symbol Error Rate
- Channel Estimation Algorithm