caa a22 4500 606204962 CHVBK 20210128101005.0 cr unu---uuuuu 210128e20150601xx s 000 0 eng 10.1007/s00034-014-9947-6 doi (NATIONALLICENCE)springer-10.1007/s00034-014-9947-6 Fast Convergence on Blind and Semi-Blind Channel Estimation for MIMO-OFDM Systems [Elektronische Daten] [Biling Zhang, Jung-Lang Yu, Wan-Ru Kuo] In this paper, blind and semi-blind subspace channel estimations with fast convergence rate are proposed for multiple-input multiple-output orthogonal frequency division multiplexing (OFDM) systems in the presence of virtual carriers. The subspace method has a main drawback of slow convergence rate when deriving the noise subspaces from the second-order statistics of received signals. This phenomenon is especially evident when the size of received signals is large. Inspired by this fact, we present a block matrix scheme (BMS) to generate a group of sub-vectors from each OFDM symbol when virtual carriers are used. The number of equivalent signals is increased and therefore, the convergence rate of channel estimation is enhanced. The semi-blind method is also investigated by incorporating subspace technology with least square scheme. The identifiability of the BMS-based channel estimation is analyzed to derive the applicable range of the BMS size. The computational complexity of the proposed channel estimation is calculated at the end. Computer simulations show that the proposed blind and semi-blind methods converge very well in channel estimation and equalization. Springer Science+Business Media New York, 2014 MIMO nationallicence OFDM nationallicence Virtual carrier nationallicence Subspace channel estimation nationallicence Toeplitz nationallicence Inter-symbol interference nationallicence Zhang Biling School of Network Education, Beijing University of Posts and Telecommunications, 100876, Beijing, People's Republic of China aut Yu Jung-Lang Department of Electrical Engineering, Fu Jen Catholic University, 24205, New Taipei City, Taiwan aut Kuo Wan-Ru Department of Electrical Engineering, Fu Jen Catholic University, 24205, New Taipei City, Taiwan aut Circuits, Systems, and Signal Processing Springer US; http://www.springer-ny.com 34/6(2015-06-01), 1993-2013 0278-081X 34:6<1993 2015 34 34 https://doi.org/10.1007/s00034-014-9947-6 text/html Onlinezugriff via DOI BK010053 XK010053 XK010000 Metadata rights reserved Springer special CC-BY-NC licence nationallicence 1 research-article jats NATIONALLICENCE NATIONALLICENCE NL-springer NATIONALLICENCE 856 40 https://doi.org/10.1007/s00034-014-9947-6 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Zhang Biling School of Network Education, Beijing University of Posts and Telecommunications, 100876, Beijing, People's Republic of China aut NATIONALLICENCE 700 1- Yu Jung-Lang Department of Electrical Engineering, Fu Jen Catholic University, 24205, New Taipei City, Taiwan aut NATIONALLICENCE 700 1- Kuo Wan-Ru Department of Electrical Engineering, Fu Jen Catholic University, 24205, New Taipei City, Taiwan aut NATIONALLICENCE 773 0- Circuits, Systems, and Signal Processing Springer US; http://www.springer-ny.com 34/6(2015-06-01), 1993-2013 0278-081X 34:6<1993 2015 34 34