| In this paper, a joint blind timing and carrier frequency offset (CFO) estimator for multiuser asynchronous multi-carrier code division multiple access (MC-CDMA) systems over frequency selective fading channel is proposed. Through properly choosing the oversampling factor and the number of received samples, the estimation can be resolved using the subspace approach. The use of decoupled subspace approach decouples the multiuser parameter estimation to multiple single user problems, thus improves the algorithm computational efficient. Using the small perturbation analysis, the approximate mean square error (MSE) in estimating CFO can be computed. The Cramér-Rao bound (CRB) is also derived to obtain the lower bound of the CFO estimation error. The accuracy of timing estimation is measured in terms of the probability of acquisition. Our simulation results show the robustness and effectiveness of the proposed joint timing and CFO estimator, in terms of its strong resistance to noises, near-far problem and multipath fading. |
| Xiaoyu Hu received the B.Eng. and M.Eng. degrees from Huazhong University of Science and Technology, Wuhan, China, in 1997 and 2000, respectively, and the Ph.D. degree from National University of Singapore, Singapore, in 2005. Currently he is a research associate with Dept of Electrical and Computer Engineering, Stevens Institute of Technology, Hoboken, NJ, USA. From 2000 to 2001, he was a Telecommunication Engineer with Guangdong Telecommunication Co., Ltd., Guangzhou, China. From 2001 to 2005, he was a research assistant at National University of Singapore and Institute for Infocomm Research, Singapore. In 2005, he was a software engineer at Motorola Co. Ltd, Singapore. His research interests include multicarrier CDMA, space-time coding, beamforming, synchronization, channel estimation, multiuser detection, and spectrally efficient spread-spectrum system.
Yong Huat Chew received the B.Eng., M.Eng. and Ph.D. degrees in electrical engineering from National University of Singapore (NUS), Singapore. He has been with the Institute for Infocomm Research (I2R) since 1996 and he is presently a Senior Scientist in I2R and an adjunct Associate Professor in National University of Singapore. His research interests are in technologies related to high spectrally efficient wireless communication systems. |