naa a22 4500 51079551X CHVBK 20180411083335.0 cr unu---uuuuu 180411e20130101xx s 000 0 eng 10.1007/s11277-011-0445-x doi (NATIONALLICENCE)springer-10.1007/s11277-011-0445-x Reduced-Complexity Decision-Directed Channel Estimation in OFDM Systems with Transmit Diversity [Elektronische Daten] [Kuo-Guan Wu, Jer-An Wu] Decision-directed channel estimation (DDCE) in orthogonal frequency-division multiplexing (OFDM) systems with transmit diversity suffers from high computation complexity in the simultaneous estimation of channel responses between the receiver and all the transmitters. Exploiting the correlation of the channel frequency response at adjacent subcarriers can help decouple the inter-antenna interference (IAI). This makes it possible to independently estimate each channel response, resulting in the reduction of computational complexity. However, existing IAI decoupling algorithms employ the least squares (LS) method for channel estimation from the IAI decoupled data. This approach is suboptimal because of the unequal variance of noise components in the decoupled data. Residual IAI, which arises from unequal channel gains at two adjacent subcarriers because of the channel frequency selectivity, occurs in the decoupled data, causing biases in the LS channel estimation. To improve the performance of reduced-complexity DDCE in transmit diversity OFDM systems, the proposed algorithm applies the best linear unbiased estimation method to independently estimate each channel response from IAI decoupled data. This approach is optimal regarding the unequal noise variances of the decoupled data. This study also exploits temporal channel correlation to remove residual IAI using the latest channel information of DDCE. Simulation results show that the proposed method can improve the performance of the reduced complexity algorithm, making it close to that of the joint estimation algorithm with significantly higher complexity. Springer Science+Business Media, LLC., 2011 OFDM nationallicence Transmit diversity nationallicence Decision-directed channel estimation nationallicence Inter-antenna interference nationallicence Least squares nationallicence Best linear unbiased estimator nationallicence Wu Kuo-Guan Department of Electrical Engineering, National Chung Hsing University, Taichung, Taiwan aut Wu Jer-An Department of Electrical Engineering, National Chung Hsing University, Taichung, Taiwan aut Wireless Personal Communications Springer US; http://www.springer-ny.com 68/1(2013-01-01), 175-185 0929-6212 68:1<175 2013 68 11277 https://doi.org/10.1007/s11277-011-0445-x text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/s11277-011-0445-x text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Wu Kuo-Guan Department of Electrical Engineering, National Chung Hsing University, Taichung, Taiwan aut NATIONALLICENCE 700 1- Wu Jer-An Department of Electrical Engineering, National Chung Hsing University, Taichung, Taiwan aut NATIONALLICENCE 773 0- Wireless Personal Communications Springer US; http://www.springer-ny.com 68/1(2013-01-01), 175-185 0929-6212 68:1<175 2013 68 11277 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer