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Timing and Frequency Synchronization for the Uplink of an OFDMA System

M. Morelli
2004 IEEE Transactions on Communications  
This paper deals with timing and frequency recovery for the uplink of an orthogonal frequency-division multiple access (OFDMA) system.  ...  Theoretical analysis and computer simulations are used to assess the performance of the proposed synchronizers.  ...  Timing and Frequency Synchronization for the Uplink of an OFDMA System Michele Morelli Abstract-This paper deals with timing and frequency recovery for the uplink of an orthogonal frequency-division multiple  ... 
doi:10.1109/tcomm.2003.822699 fatcat:7kknkpllhncmvgglpri2faj2se

Joint Timing Synchronization and Channel Estimation Using Perfect Sequence in Uplink Time Domain Synchronous OFDMA

M. Lakshmanan, P.S. Mallick, L. Nithyanandan
2016 International Journal of Electronics and Telecommunications  
This leads to multiple user interference due to timing offset and frequency offset. In this paper, the effect of timing offset and channel estimation in mobile broadband system is analysed.  ...  Time Domain Synchronous Orthogonal Frequency Division Multiple Access (TDS-OFDMA) is used in mobile broadband wireless access scheme in uplink transmission.  ...  In this paper, an efficient method for joint timing synchronization and channel estimation in uplink TDS-OFDMA is proposed using perfect sequence.  ... 
doi:10.1515/eletel-2016-0030 fatcat:hrevzotw5jadrcov3i5y6nrk64

Low-Complexity Orthogonal Spectral Signal Construction for Generalized OFDMA Uplink With Frequency Synchronization Errors

Zhongren Cao, Ufuk Tureli, Yu-Dong Yao
2007 IEEE Transactions on Vehicular Technology  
In an unsynchronized OFDMA uplink, each user has a different carrier frequency offset (CFO) relative to the common uplink receiver, which results in the loss of orthogonality among subcarriers and thereby  ...  The interference in the generalized OFDMA uplink due to frequency synchronization errors is characterized in a multiuser signal model.  ...  ACKNOWLEDGMENT The authors would like to thank the reviewers and the editor of this paper for their valuable comments and suggestions.  ... 
doi:10.1109/tvt.2007.895601 fatcat:ech4groprjdpjoz2sayvmgqjry

Comparison of OFDMA and GFDMA for Next-Generation PONs

Arsalan Saljoghei, Arman Farhang, Colm Browning, Philip Perry, Nicola Marchetti, Linda E. Doyle, Liam P. Barry
2017 Journal of Optical Communications and Networking  
Moreover, two methods are proposed for achieving synchronization in the uplink channel of PONs, enabling high spectral efficiency.  ...  This paper examines and compares the use of orthogonal frequency division multiple access (OFDMA) and generalized frequency division multiple access (GFDMA) multicarrier formats in next-generation passive  ...  ACKNOWLEDGMENT This work has been jointly supported through CONNECT (13/RC/2077) and IPIC (12/RC/2276) research grants.  ... 
doi:10.1364/jocn.9.001064 fatcat:gnkaszi3qzgs3phyknagwoccxq

Deterministic Multiuser Carrier-Frequency Offset Estimation for Interleaved OFDMA Uplink

Z. Cao, U. Tureli, Y.-D. Yao
2004 IEEE Transactions on Communications  
This paper exploits the inner structure of the signals for CFO estimation in the uplink of interleaved OFDMA systems.  ...  A new uplink signal model is presented, and an estimation algorithm based on the signal structure is proposed for estimating the CFOs of all users using only one OFDMA block.  ...  ACKNOWLEDGMENT The authors would like to thank the reviewers and the paper editor for their valuable comments and suggestions.  ... 
doi:10.1109/tcomm.2004.833183 fatcat:j2o6nzi24rbjncguoet7usvsjm

Synchronization Techniques for Orthogonal Frequency Division Multiple Access (OFDMA): A Tutorial Review

Michele Morelli, C.-C. Jay Kuo, Man-On Pun
2007 Proceedings of the IEEE  
This paper provides a comprehensive survey of the latest results in the field of synchronization for OFDMA systems, and the authors have endeavored to include ample tutorial content.  ...  Even though the OFDMA concept is simple in its basic principle, the design of a practical OFDMA system is far from being a trivial task.  ...  Section III quantifies the effects of timing and frequency synchronization errors on the performance of an OFDMA system.  ... 
doi:10.1109/jproc.2007.897979 fatcat:yclaxa734nd75l7v6ore6drzkq

Robust OFDMA Uplink Synchronization by Exploiting the Variance of Carrier Frequency Offsets

Zhongshan Zhang, Wei Zhang, C. Tellambura
2008 IEEE Transactions on Vehicular Technology  
For an OFDMA uplink, we model the frequency offset for each user as an independent and identically distributed (i.i.d.) random variable with mean zero and variance σ 2 .  ...  In this paper, the uplink frequency offset estimation for orthogonal frequency-division multiplexing access (OFDMA) is discussed.  ...  A reliable one-block OFDMA uplink synchronization algorithm is proposed in [3] . An uplink timing and frequency synchronization method for an OFDMA system is proposed in [2] .  ... 
doi:10.1109/tvt.2007.912596 fatcat:2um4ldvv7bfazig5onyjkixb7u

Time and Frequency Synchronization for OFDMA Uplink System using the SAGE Algorithm

Jong-ho Lee, Seong-cheol Kim
2007 IEEE Transactions on Wireless Communications  
In this letter, we propose an iterative time and frequency synchronization scheme for orthogonal frequencydivision multiple access (OFDMA) uplink system using the space-alternating generalized expectation-maximization  ...  Then, the maximization step is utilized in the timing and frequency offset estimation of each asynchronous user using the MAI-canceled signals.  ...  ACKNOWLEDGMENT The authors would like to thank the paper editor and the reviewers for their valuable comments and suggestions.  ... 
doi:10.1109/twc.2007.348309 fatcat:5y2kdbar2rhnvhovitaui22b5y

A COMPREHENSIVE REVIEW OF MODULATION TECHNIQUES USED IN LONG TERM EVOLUTION

Sunita Kumari, T. L. Singal
2015 Journal on Today s Ideas-Tomorrow s Technologies  
Design of wireless communication system has been an important and challenging problem due to the nature of wireless channel. There are number of factors involved in the performance of a LTE system.  ...  Orthogonal Frequency Division multiple access (OFDma) and Single Carrier Frequency Division multiple access (SC-FDma) are a dominant part of future mobile communication.  ...  The PraCH channel performs uplink timing and frequency synchronization. This is performed by user equipment after downlink synchronization. Zadoff Chu (ZC) sequence is used because of its properties.  ... 
doi:10.15415/jotitt.2015.31006 fatcat:dvj3bfu5lzgbjerqxxdrnevjva

Blind Carrier Frequency Synchronization for the Uplink of Interleaved OFDMA Systems

J. Y. HWANG, K. S. KIM, Y.-S. KIM, K.-C. WHANG
2008 IEICE transactions on communications  
In this letter, a novel blind CFO estimation algorithm for the uplink of an OFDMA system is proposed.  ...  Therefore, the proposed estimator can be applied to OFDMA systems with an arbitrary subcarrier assignment over the entire bandwidth, including IEEE 802.16e, to obtain sufficient frequency diversity in  ...  Acknowledgments This work was supported by the MIC (Ministry of Information and Communication), Korea, under the ITRC (Information Technology Research Center) support program supervised by the IITA (Institute  ... 
doi:10.1093/ietcom/e91-b.1.368 fatcat:q5hssy7gtveonnoi2lbziktxbm

Maximum-likelihood synchronization and channel estimation for OFDMA uplink transmissions

M.-O. Pun, M. Morelli, C.-C.J. Kuo
2006 IEEE Transactions on Communications  
Maximum-likelihood estimation of the carrier frequency offset (CFO), timing error, and channel response of each active user in the uplink of an orthogonal frequency-division multiple-access system is investigated  ...  This results in an estimation algorithm of a reasonable complexity which is suitable for practical applications.  ...  The above synchronization and channel estimation tasks are particularly challenging in the uplink of an OFDMA system where each user has his/her own CFO, timing error, and channel response.  ... 
doi:10.1109/tcomm.2006.873093 fatcat:cxdi4vejzrg7rjyfjrflluc4h4

A joint ML estimation technique for timing, CFO and channel for OFDMA uplink transmissions

S. M. Sameer, V. P. Thafasal Ijyas
2011 2011 National Conference on Communications (NCC)  
This paper addresses the issue of joint maximumlikelihood (ML) estimation of carrier frequency offset (CFO), timing error and channel response for OFDMA uplink transmissions.  ...  Index Terms-Orthogonal frequency division multiple access (OFDMA), channel estimation, frequency synchronization, timing synchronization, maximum likelihood estimation (MLE) .  ...  an OFDMA system.  ... 
doi:10.1109/ncc.2011.5734722 fatcat:ez4mjjtzsfbnzpki554qybrrxe

SAGE based iterative receiver for joint synchronization and channel estimation in uplink MIMO-OFDMA systems

Zheng JIANG, Xiao-fang QIN, Xin ZHANG, Yong-yu CHANG
2008 Journal of China Universities of Posts and Telecommunications  
A new Turbo iterative receiver structure is proposed for the uplink multiple-input multiple-output orthogonal frequency division multiple access (MIMO-OFDMA) systems.  ...  (i.e., timing offset, carrier frequency offset, channel state information, etc.) sequentially for each user.  ...  [4, 5] evolves the SAGE algorithm into timing and frequency synchronization for OFDMA uplink system, but the multiple-antenna technology is not considered.  ... 
doi:10.1016/s1005-8885(08)60115-6 fatcat:4dvxcf2qbbbxlmosw2btzm2rta

Efficient CFO Compensation Method in Uplink OFDMA for Mobile WiMax

Lakshmanan Muthukaruppan, Parthasharathi Mallick, Nithyanandan Lakshmanan, Sai Krishna Marepalli
2016 Journal of ICT Research and Applications  
Mobile WiMax uses Orthogonal Frequency Division Multiple Access (OFDMA) in uplink where synchronization is a complex task as each user presents a different carrier frequency offset (CFO).  ...  The difference between the CFOs of two OFDMA symbols lies within the range of RFO that is not considered in the conventional compensation techniques, such as the SI-MUIC, DC-SC and IEC compensation techniques  ...  Conclusion In this paper, an efficient CFO compensation technique in uplink OFDMA for mobile WiMAX was proposed.  ... 
doi:10.5614/itbj.ict.res.appl.2016.10.2.4 fatcat:klwejxvadzacld4ymax4q6gcpq

Iterative Equalization and Decoding for Unsynchronized OFDMA Uplink Transmissions

Man-on Pun, Michele Morelli, C.-c. Kuo
2006 IEEE Vehicular Technology Conference  
For the uplink transmission of a coded OFDMA system, we present an iterative receiver that performs joint frequency offset acquisition, channel estimation and maximum a posteriori (MAP)-based decoding  ...  Simulations indicate that the proposed scheme provides accurate decoding for unsynchronized OFDMA uplink transmissions over frequency-selective fading channels.  ...  Two critical issues in the design of an OFDMA uplink system are frequency synchronization and channel estimation.  ... 
doi:10.1109/vtcf.2006.189 dblp:conf/vtc/PunMK06 fatcat:6aeixxhynraezf4xgwlaaa7hjm
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