Efficient Channel Estimation Based on LTE in OFDM
| International Journal of Computer Trends and Technology (IJCTT) | |
© - November Issue 2013 by IJCTT Journal | ||
Volume-5 Issue-1 | ||
Year of Publication : 2013 | ||
Authors :Mathe Sowmya , CH. Ravi Kumar. |
Mathe Sowmya , CH. Ravi Kumar."Efficient Channel Estimation Based on LTE in OFDM"International Journal of Computer Trends and Technology (IJCTT),V5(1):49-54 November Issue 2013 .ISSN 2231-2803.www.ijcttjournal.org. Published by Seventh Sense Research Group.
Abstract:- in this paper, we propose an iterative detecting and decoding method in LTE Downlink OFDM system based on reference aided channel estimation. Estimates of the complex channel gain and variance of the additive noise are derived first from known reference symbols and channel estimate filter. After turbo decoding, the decoded bits have been obtained. In order to obtain estimates of channel gain more accuracy, we adopted more reference symbols which modulate the decoded bits at the receiver again to estimate the channel frequency response. Also the mapping position of the OFDM symbols is consistent with first transmission. Through estimation of the channel iteratively, we can use more systems bits as iterative reference symbols. Simulation results shows that through the iterative channel estimation, the initial insert reference symbols have been reduced, the accuracy of channel estimation improved effectively and the bits error rate of the OFDM system can approach the perfect channel estimates.
References -
[1] Luis Angel Maestro Ruiz de Temino and Carles Navarro I Manchon, “Iterative Channel Estimation with Robust Wiener Filtering in LTE Downlink,”IEEE Trans.Commn.,Aug, 2008
[2] Andrea Ancora , Calogero , Bona Dirk T.M. Slock , “Down-Sampled Impulse Respponse Least-Squares Channel Estimation For LTE OFDMA, ”IEEE Trans.,ICASSP ’07.
[3] Farzad Foroughi , Johan Lofgren, Ove Edfors,”Channel estimation for a Mobile Terminal in a Multi-Standard Enviroment (LTE and DVBH).” IEEE Trans. Aug 2009.
[4] Members of 3GPP, “Technical Sepcification Group Radio Access Network;Physical Channels and Modulation (3GPP TS 36.211 Version 8.8.0),”3GPP,Tech.Spe.,Sep,2009..
[5] L. Bahl, J. Cocke, F. Jelinek, and J. Raviv, “Optimal decoding of linear codes for minimizing symbol error rate,” IEEE Trans. Inf. Theory, vol, IT-20, no. 2, pp.284-287, Mar.1974
[6] G. Bauch, H. Khoram, J. Haganauer, “Iterative equalization and decoding in mobile communications systems,” in Proc. 2nd EPMCC, 3.ITGFachtagung “Mobile Kommunikation,” Sep./Oct. 1997, pp. 307– 312.VDE/ITG..
[7] P. Robertson, P. Hoeher, and E. Villebrun, “Optimal and sub-optimal maximum a posteriori algorithms suitable for turbo decoding,” Eur. Trans. Telecommun., vol. 8, no. 2, pp. 119–125, 1997.
[8] J. A. Erfanian, S. Pasupathy, and G. Gulak, “Reduced complexity symbol detectors with parallel structures for ISI channels,” IEEE Trans.Commun. , vol. 42, no. 234, pp. 1661–1671, Feb.–Apr. 1994.
Keywords :— channel estimation; turbo; LS; iterative.