The Experts below are selected from a list of 27 Experts worldwide ranked by ideXlab platform
Sandeep Shukla - One of the best experts on this subject based on the ideXlab platform.
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timing and carrier frequency offset estimation using selective Extended Cyclic Prefix for correlation sequence for ofdm systems
Wireless Personal Communications, 2018Co-Authors: Sandeep Shukla, Vijay TripathiAbstract:In this paper a novel technique for timing and carrier frequency offset (CFO) estimation for orthogonal frequency division multiplexing (OFDM) systems is presented. This technique is a modification of Extended Cyclic Prefix for correlation sequence (ECPCS) based technique, called as selective Extended Cyclic Prefix for correlation sequence (SECPCS) based technique. In Cyclic Prefix (CP) based technique, magnitude of timing metric near the exact starting point of CP is quite similar which causes problem in timing estimation. SECPCS is utilized in order to increase the difference between magnitudes of timing metric at the exact starting point of time of CP and its adjacent timing instants. In SECPCS technique, first of all correlation length of CP is Extended using available CP samples and then those sequences which enlarge the difference in the magnitude of timing metric is selected. In the proposed technique the difference between magnitude of timing metric at exact starting point and its adjacent timing instants is significantly large compared to the previous techniques. The performance of different techniques is evaluated in terms of mean square error (MSE) in estimation of timing and CFO estimate. Further signal-to-interference-plus-noise ratio (SINR) loss of different techniques in different channel conditions is also estimated. From the simulation results it is observed that under different channel conditions, performance of the proposed SECPCS based technique is significantly better than previous techniques.
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Performance Evaluation of Timing Estimation Technique Using Extended Cyclic Prefix for Correlation Sequence for OFDM Systems
Wireless Personal Communications, 2017Co-Authors: Sandeep Shukla, Vijay Shanker TripathiAbstract:This paper presents an analysis of symbol timing offset (STO) estimation method for orthogonal frequency division multiplexing systems. The proposed method does not require any preamble and with the use of available Cyclic Prefix (CP) samples we have proposed an Extended CP. The Extended CP is used to exploit more number of correlation products in correlation sequence so that a more accurate starting point of any symbol can be estimated. A simplified maximum likelihood estimation process for proposed timing estimation technique is given which enables us much more accurate timing estimate due to decreased error variance. The performance of the proposed method is evaluated in terms of mean square error of timing estimator against different signal to noise ratio values and in terms of error distribution of the estimators with and without the effect of carrier frequency offset in various channel scenarios such as AWGN, HIPERLAN/2A and HIPERLAN/2E. Simulation results shows that proposed method has significantly better performance compared to the CP based method for STO estimation.
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correction to performance evaluation of timing estimation technique using Extended Cyclic Prefix for correlation sequence for ofdm systems
Wireless Personal Communications, 2017Co-Authors: Sandeep Shukla, Vijay TripathiAbstract:Equation 13 was incomplete in the initial online publication. The original article has been corrected.
Vijay Tripathi - One of the best experts on this subject based on the ideXlab platform.
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timing and carrier frequency offset estimation using selective Extended Cyclic Prefix for correlation sequence for ofdm systems
Wireless Personal Communications, 2018Co-Authors: Sandeep Shukla, Vijay TripathiAbstract:In this paper a novel technique for timing and carrier frequency offset (CFO) estimation for orthogonal frequency division multiplexing (OFDM) systems is presented. This technique is a modification of Extended Cyclic Prefix for correlation sequence (ECPCS) based technique, called as selective Extended Cyclic Prefix for correlation sequence (SECPCS) based technique. In Cyclic Prefix (CP) based technique, magnitude of timing metric near the exact starting point of CP is quite similar which causes problem in timing estimation. SECPCS is utilized in order to increase the difference between magnitudes of timing metric at the exact starting point of time of CP and its adjacent timing instants. In SECPCS technique, first of all correlation length of CP is Extended using available CP samples and then those sequences which enlarge the difference in the magnitude of timing metric is selected. In the proposed technique the difference between magnitude of timing metric at exact starting point and its adjacent timing instants is significantly large compared to the previous techniques. The performance of different techniques is evaluated in terms of mean square error (MSE) in estimation of timing and CFO estimate. Further signal-to-interference-plus-noise ratio (SINR) loss of different techniques in different channel conditions is also estimated. From the simulation results it is observed that under different channel conditions, performance of the proposed SECPCS based technique is significantly better than previous techniques.
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correction to performance evaluation of timing estimation technique using Extended Cyclic Prefix for correlation sequence for ofdm systems
Wireless Personal Communications, 2017Co-Authors: Sandeep Shukla, Vijay TripathiAbstract:Equation 13 was incomplete in the initial online publication. The original article has been corrected.
Vijay Shanker Tripathi - One of the best experts on this subject based on the ideXlab platform.
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Performance Evaluation of Timing Estimation Technique Using Extended Cyclic Prefix for Correlation Sequence for OFDM Systems
Wireless Personal Communications, 2017Co-Authors: Sandeep Shukla, Vijay Shanker TripathiAbstract:This paper presents an analysis of symbol timing offset (STO) estimation method for orthogonal frequency division multiplexing systems. The proposed method does not require any preamble and with the use of available Cyclic Prefix (CP) samples we have proposed an Extended CP. The Extended CP is used to exploit more number of correlation products in correlation sequence so that a more accurate starting point of any symbol can be estimated. A simplified maximum likelihood estimation process for proposed timing estimation technique is given which enables us much more accurate timing estimate due to decreased error variance. The performance of the proposed method is evaluated in terms of mean square error of timing estimator against different signal to noise ratio values and in terms of error distribution of the estimators with and without the effect of carrier frequency offset in various channel scenarios such as AWGN, HIPERLAN/2A and HIPERLAN/2E. Simulation results shows that proposed method has significantly better performance compared to the CP based method for STO estimation.
Anis Charrada - One of the best experts on this subject based on the ideXlab platform.
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svm based on lmmse for high speed coded ofdm channel with normal and Extended Cyclic Prefix
Physical Communication, 2018Co-Authors: Anis CharradaAbstract:Abstract We propose in this article, a Linear Minimum Mean Squares Error-Support Vector Machine regression (LMMSE-SVR) method which is employed high-speed 3GPP Long Term Evolution (LTE) downlink coded channel estimation environment. LMMSE-SVR approach is applied to track and estimate the fast fluctuations caused by Doppler effect of a 3GPP realistic Extended Vehicular A model (EVA) channel. We integrate in this contribution both channel estimation at pilot symbols and interpolation at data symbols into the LMMSE-SVR process with and without turbo coding scheme. Bit Error Rate (BER) performance of our channel environment estimation proposal is validated via simulation of LTE downlink system for both coded and uncoded high-speed scenarios with normal and Extended Cyclic Prefix (CP) modes.
Abayomi M Ajofoyinbo - One of the best experts on this subject based on the ideXlab platform.
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on ultra Extended Cyclic Prefix in orthogonal frequency division multiplexing ofdm systems the case of lte downlink
Communications and Network, 2013Co-Authors: Abayomi M AjofoyinboAbstract:Orthogonal Frequency Division Multiplexing (OFDM) is a multi-carrier scheme used in modern broadband wireless communication systems to transmit data over a number of orthogonal subcarriers. When transmitted signals arrive at the receiver by more than one path of different length, the received signals are staggered in time; this is multipath propagation. To mitigate the effect of dispersed channel distortion caused by random channel delay spread, Cyclic Prefix (CP) is introduced to eliminate Inter-Symbol Interference (ISI). In the literature, researchers have focused on carrying out investigations (or studies) mainly on the two existing CP insertions, namely: normal and Extended CPs. Both CPs have limitations with respect to handling channel delay spreads. In the current work, a new CP, herein referred to as “ultra Extended” CP is proposed to address delay spreads beyond the limits of the normal and Extended CPs. The efficacy of the proposed ultra Extended CP is tested via simulation under different scenarios. It is shown by the results obtained that the proposed CP can efficiently handle delay spreads beyond the limits of the existing normal and Extended CP, and can indeed be implemented in the design of future telecommunication systems to accommodate higher channel delay spreads and it ensures wider cell coverage.
