Filters








182 Hits in 8.5 sec

Overview on synchronization in OFDM systems

Chandresh D. Parekha, Jayesh M. Patel
2016 2016 International Conference on Advances in Computing, Communication, & Automation (ICACCA) (Spring)  
It focuses on various symbol timing and carrier frequency acquisition schemes including coarse and fine synchronization techniques, using cyclic prefix or training symbols.  ...  Orthogonal Frequency Division Multiplexing (OFDM) is a advance bandwidth efficient digital modulation technique highly adopted for the broadband wireless services because it gives high performance in the  ...  Carrier frequency offset also down the received signal amplitude notably along with ICI. It is also found that the effect of CFO depends on type of modulation techniques used OFDM system.  ... 
doi:10.1109/icacca.2016.7578862 fatcat:vkr6cpp2b5frdmctb53lm7hjkm

Blind frequency offset estimator for OFDM systems

Sakina Atoui, Noureddine Doghmane, Saddek Afifi
2019 TELKOMNIKA (Telecommunication Computing Electronics and Control)  
The joint maximum-likelihood (ML) estimation of the symbol-time and carrier frequency offset [14] , referred to as VDB-MLA, is assumed in additive white Gaussian noise (AWGN) channels.  ...  This paper explores the tradeoff between the length of the cyclic prefix and the performances of the OFDM system. It also studies the effect of carrier frequency offset (CFO) on OFDM systems.  ...  The developed carrier frequency offset estimator is derived when the correlation coefficient is high to deal with the carrier frequency offset.  ... 
doi:10.12928/telkomnika.v17i6.11957 fatcat:kdszrtj6xrdhnkaoql6wet546y

A Novel Hierarchical Low Complexity Synchronization Method for OFDM Systems

Pramod Udupa, Olivier Sentieys, Pascal Scalart
2013 2013 IEEE 77th Vehicular Technology Conference (VTC Spring)  
Based on the proposal of new training symbol, a threshold based timing metric is designed for accurate estimation of start of OFDM symbol in a frequency selective channel.  ...  Frequency offset estimation is also done for the proposed training symbol. The performance of the proposed timing metric is evaluated using simulation results.  ...  Comparing the proposed method with Choi, Park and Zhou's method, a saving of Nsym−(2Ncyp+1) Nsym is obtained for In case of Minn, to perform the fine timing estimation, Maximum Likelihood (ML) channel  ... 
doi:10.1109/vtcspring.2013.6691838 dblp:conf/vtc/UdupaSS13 fatcat:fosa6wd5fvfo3ev3sc74q6qrxu

Synchronization for OFDM-Based Systems [chapter]

Yu-Ting Sun, Jia-Chin Li
2011 Recent Advances in Wireless Communications and Networks  
Hard cover, 454 pages Publisher InTech This book focuses on the current hottest issues from the lowest layers to the upper layers of wireless communication networks and provides â€oereal-time†research  ...  The authors have made every effort to systematically organize the information on these topics to make it easily accessible to readers of any level.  ...  Example 2: Data-aided, preamble, integral/coarse frequency offset Previous works often employ signal-estimation techniques on a time-indexed basis in the time direction.  ... 
doi:10.5772/24690 fatcat:ovkxmvfdgbhffho62nmvywaqqm

Time Synchronization Algorithm In Ieee802.11A Communication System

P. Duhamel, Nguyen Linh-Trung, Anissa Mokraoui, Cong Luong Nguyen
2012 Zenodo  
Publication in the conference proceedings of EUSIPCO, Bucharest, Romania, 2012  ...  OFDM synchronization aims to find accurate symbol timing and the carrier frequency offset.  ...  In [3] and [4] , the authors exploit the redundant information contained in the CP of data, and hence the time and frequency offsets are estimated from the maximum log-likelihood function.  ... 
doi:10.5281/zenodo.52206 fatcat:uoifm7skpjhitmbypzkbsxrc7a

Robust time-domain timing and frequency synchronization for OFDM systems

Adegbenga Awoseyila, Christos Kasparis, Barry Evans
2009 IEEE transactions on consumer electronics  
It uses a preamble consisting of only one training symbol with two identical parts to achieve reliable timing and frequency accuracy in the time-domain, over a wide frequency estimation range which can  ...  A robust and efficient technique for frame/symbol timing and carrier frequency synchronization in OFDM systems is presented.  ...  On the other hand, OFDM is very sensitive to carrier frequency offsets in the received signal.  ... 
doi:10.1109/tce.2009.5174399 fatcat:zkttbdx73vfzfafeaconukvxli

OFDM Synchronization Techniques for 802.11ac WLAN

Chandresh D. Parekha, Jayesh M. Patel
2018 International Journal of Wireless and Microwave Technologies  
There are many issues with OFDM too and one of them is synchronization between orthogonal frequency channels at receiver.  ...  Later, with development of digital signal processing, OFDM had been accepted for most of the high speed communication systems such as HDSL, ADSL, VHDSL, HDTV, DVB and DAB [1] .  ...  12 OFDM Synchronization Techniques for 802.11ac WLAN  ... 
doi:10.5815/ijwmt.2018.04.01 fatcat:wo7vwtudwfd6bocm4hk7xp6cem

A Consistent OFDM Carrier Frequency Offset Estimator Based on Distinctively Spaced Pilot Tones

J. Lei, T.-S. Ng
2004 IEEE Transactions on Wireless Communications  
A pilot-tone-based maximum likelihood estimator (PBMLE) for carrier frequency offset (CFO) in orthogonal frequency-division multiplexing (OFDM) systems is proposed.  ...  As a result of this preamble configuration, a large estimation range equal to the bandwidth of the OFDM signal can be achieved.  ...  ACKNOWLEDGMENT The authors wish to thank the editor and the anonymous reviewers for their helpful comments and suggestions in improving the quality of this paper.  ... 
doi:10.1109/twc.2004.825350 fatcat:yxgaxesw75cqhaypthdb3ansqm

Frequency Synchronization Algorithms for MIMO-OFDM Systems with Periodic Preambles

Jian Sun, Fudong Li, Cheng-Xiang Wang, Xuemin Hong, Dongfeng Yuan
2014 International Journal of Distributed Sensor Networks  
Moreover, phases or differential phases obtained from the autocorrelation of periodic sequences with different delays can be used to estimate carrier frequency offset (CFO).  ...  This paper addresses the problem of frequency synchronization in multiple-input multiple-output (MIMO) orthogonal frequencydivision multiplexing (OFDM) systems with periodic preambles.  ...  Acknowledgments The authors would gratefully acknowledge the support from National Natural Science Foundation of China (NSFC) (nos.  ... 
doi:10.1155/2014/740906 fatcat:2pgootzqhjaijaiyldim6c6lc4

A Low Complexity Frequency Offset Estimation For Mb-Ofdm Based Uwb Systems

Wang Xue, Liu Dan, Liu Ying, Wang Molin, Qian Zhihong
2009 Zenodo  
Utilizing a half-cycle Constant Amplitude Zero Auto Correlation (CAZAC) sequence as the preamble sequence, the estimator with a semi-cross contrast scheme between two successive OFDM symbols is proposed  ...  Compared to the reference estimators, the proposed method achieves significantly less complexity (about 50%) for all preamble patterns of the MB-OFDM systems.  ...  [8] derived the maximum likelihood (ML) estimator for frequency offset in MB-OFDM based UWB systems following [5] using the last two successive OFDM symbols of the packet synchronization sequence  ... 
doi:10.5281/zenodo.1083550 fatcat:mq4mx4lsaneg3bprv6jinzwm5i

Frequency synchronization for MIMO OFDM wireless LAN systems

T.C.W. Schenk, A. van Zelst
2003 2003 IEEE 58th Vehicular Technology Conference. VTC 2003-Fall (IEEE Cat. No.03CH37484)  
This paper proposes an accurate and time-efficient technique for frequency synchronization of multiple-input multiple-output (MIMO) orthogonal frequency division multiplexing (OFDM) systems.  ...  The technique uses a preamble and is thus especially suitable for burst mode communication. The preamble consists of training sequences simultaneously transmitted from the various transmit antennas.  ...  Larger ranges can be achieved by first performing a coarse CFO estimation by preceding the preamble with training symbols with shorter length N p , as done in [1]. IV.  ... 
doi:10.1109/vetecf.2003.1285127 fatcat:dcafxzdk2zdjnk4mopttms3t74

Ml Symbol Synchronization For General Mimo-Ofdm Systems In Unknown Frequency-Selective Fading Channels

Jean Pierre Cances, Jean Michel Dumas, Guillaume Ferré, Vahid Meghdadi, Amir Saemi, Mohammad Reza Zahabi
2006 Zenodo  
Publication in the conference proceedings of EUSIPCO, Florence, Italy, 2006  ...  In fact we extend the method of [15] , to develop a maximum-likelihood (ML) symbol synchronizer for a general MIMO-OFDM system on frequency selective channels.  ...  He described a technique to estimate frequency offset by using a repeated training sequence and derived maximum likelihood estimation procedure.  ... 
doi:10.5281/zenodo.53313 fatcat:hv3ollqdmzfundmhiypzr72vzq

Nonlinearity-Based Ranging Technique in SC-FDE Communication System With Oversampled Signals

Xi Pan, Shouliang Liu, Shuo Yan
2019 IEEE Access  
Combining with the coarse timing procedure, we proposed a fine ranging method relying on the oversampled signals in SC-FDE receiver employing Qth-power nonlinearity, and then analyzed its estimation mean  ...  A new pattern of the preamble and the unique word was designed for SC-FDE system, where the preamble can be exploited in correlation-based timing algorithm to obtain impulse-like timing metric.  ...  Some properties of the OFDM signals in both time and frequency domains are utilized in the super-resolution algorithms, e.g. the maximum likelihood algorithm and the multiple-signal classification (MUSIC  ... 
doi:10.1109/access.2019.2910754 fatcat:m6txzjsj2re4lk4aqsvz5bvbmu

Physical layer orthogonal frequency-division multiplexing acquisition and timing synchronization security

Matthew J. La Pan, T. Charles Clancy, Robert W. McGwier
2014 Wireless Communications and Mobile Computing  
In particular, we analyze the performance of a maximum likelihood synchronization estimator against highly correlated jamming attacks.  ...  Most of the OFDM methods for synchronization were not designed with security in mind.  ...  ACKNOWLEDGEMENTS The authors would like to thank fred harris for his insightful discussions and correspondences on the topic.  ... 
doi:10.1002/wcm.2500 fatcat:ifgfvaevk5dsvaiurnji3eayca

Estimation of Carrier Frequency Offset With I/Q Mismatch Using Pseudo-Offset Injection in OFDM Systems

Ming-Fu Sun, Jui-Yuan Yu, Terng-Yin Hsu
2008 IEEE Transactions on Circuits and Systems Part 1: Regular Papers  
This work presents a novel carrier frequency offset (CFO) estimation algorithm, based on pseudo-CFO (P-CFO), to estimate the CFO value under the conditions of I/Q mismatch for direct conversion structures  ...  INTRODUCTION O RTHOGONAL frequency-division multiplexing (OFDM) is a spectrally efficient signaling method for communication over frequency-selective fading channels [1], [2].  ...  They also want to thank the members of the ISIP laboratory of Computer Science, National Chiao-Tung University, Taiwan, R.O.C., for many helpful suggestions in chip design and testing.  ... 
doi:10.1109/tcsi.2008.916426 fatcat:ilmxpwywnnhx7ehb6pnjltdh4a
« Previous Showing results 1 — 15 out of 182 results