The Journal of Supercomputing
A Novel Technique for Channel Estimation and Equalization for High Mobility OFDM Systems
Wireless Personal Communications: An International Journal
OFDM Channel Estimation and Signal Detection on Nonintegral-Delay and Fast Time-Varying Channels
RSKT '09 Proceedings of the 4th International Conference on Rough Sets and Knowledge Technology
ICHIT'06 Proceedings of the 1st international conference on Advances in hybrid information technology
Channel estimation for OFDM system with two training symbols aided and polynomial fitting
IEEE Transactions on Communications
A model reduction approach for OFDM channel estimation under high mobility conditions
IEEE Transactions on Signal Processing
International Journal of Information and Communication Technology
Differential demodulation of OFDM based on SOM
ICNC'05 Proceedings of the First international conference on Advances in Natural Computation - Volume Part II
| Hi-index | 0.43 |
In orthogonal frequency division multiplexing (OFDM) systems, channel variations within an OFDM block destroy orthogonality between subcarriers, resulting in intercarrier interference (ICl), which increases an error floor in proportional to normalized Doppler frequency. To mitigate the effects of channel variations, many schemes have been proposed, but they are computationally complex or at the price of sacrificing spectral efficiency. In this paper, we first provide an ICI analysis in both time- and frequency-domain while existing literatures analyze the ICI effects mainly in the frequency domain. Based on this analysis, we then propose a novel ICI suppression technique, which uses iterative ICI cancellation in time domain and has a computational complexity that is linear in the OFDM symbol length. Channel estimation in rapidly time-varying scenarios is critical for ICl suppression and coherent demodulation. We also propose a scheme for estimating the channel parameters varying within an OFDM block. Along with the channel estimation scheme, we investigate the issue of optimum pilot tone placement. Theoretical analysis and simulation results show that the proposed ICl suppression method and channel estimation scheme have low computational complexity and good performance for most Doppler frequency of practical importance.