Author: Zahirul IslamPublisher:
ISBN: 9781321266184
Category : Electronic dissertations
Languages : en
Pages : 108
Book Description
Channel Estimation and Correction Methods for OFDMA Based LTE Downlink System
Author: Zahirul IslamPublisher:
ISBN: 9781321266184
Category : Electronic dissertations
Languages : en
Pages : 108
Book Description
Performance Evaluation of Channel Estimation Techniques
Author: Kahsay KirossPublisher:
ISBN: 9783330085756
Category :
Languages : en
Pages : 104
Book Description
Decision-feedback Equalization and Channel Estimation for Single-carrier Frequency Division Multiple Access
Author: An Efficient Channel Estimation Algorithm for LTE Downlink Systems
Author: 朱柏安Low-complexity Channel Estimation for LTE-based Systems in Time-varying Channels
Author: Ahmad El-QurnehPublisher:
ISBN:
Category : Interpolation
Languages : en
Pages : 80
Book Description
"For its key role in achieving high data rates, the need to develop a low-complexity channel estimator is one of the main targets in the Long-Term Evolution (LTE) research development. With high-mobility users in LTE-Orthogonal Frequency Division Multiplexing (LTE-OFDM) systems, channel estimator design becomes a challenging problem, since the estimator needs to estimate more channel parameters than in slow fading channels, which may make the channel estimation impractical. A low-complexity channel estimator is developed for LTE high-mobility systems based on the Piecewise Linear (PWL) model and the channel time-frequency correlation relationships. The channel estimator and interpolator is tested under different LTE channel models for various mobile velocities and showed an improvement in the Bit Error Rate (BER) performance from 6% to 2% compared to the conventional linear interpolation technique with only 33.2% increase in the required processing time for a doppler frequency of 300 Hz. The proposed interpolation technique is insensitive to the change in the mobile velocity to some extent; this makes the channel estimator more practical and robust to any change in the channel statistics."--Page ii.
Pilot Based Channel Estimation 3GPP LTE Downlink
Author: Ankit Ashok AgarwalPublisher:
ISBN:
Category :
Languages : en
Pages :
Book Description
Channel estimation is an important part for the design of receivers in mobile communication systems. In order to recover the transmitted information correctly, the effect of the channel on the transmitted signal must be correctly estimated. In this thesis, the pilot based channel estimation algorithms for 3GPP LTE downlink is studied. Channel estimation algorithms such as Least Square (LS), Minimum Mean Square Error (MMSE) and Modified MMSE (M-MMSE) channel estimation algorithm have been evaluated for LTE downlink 5 MHz bandwidth configuration. The performance of these algorithms for Block type and Comb type pilot arrangement has been measured in terms of Bit Error Rate (BER). For Comb type pilot arrangement, the performance of Linear Interpolation (LI), Spline Cubic Interpolation (SCI) and Low Pass Interpolation (LPI) methods have been compared. Though higher order interpolation is used for better interpolation accuracy, the improvement in performance is not proven for all cases and for some cases Linear Interpolation can give better performance. For cases when the subcarrier spacing is very small compared to the coherence bandwidth which is a result of small delay spread, Linear Interpolation can give better performance in terms of BER. The ITU outdoor to indoor and pedestrian test environment channel model A, which has a small R.M.S. delay spread of 45 ns, has been used for all simulations. The performance of Comb type pilot arrangement with different pilot spacing has also been compared.
Understanding LTE with MATLAB
Author: Houman ZarrinkoubPublisher: John Wiley & Sons
ISBN: 1118443454
Category : Technology & Engineering
Languages : en
Pages : 513
Book Description
An introduction to technical details related to the Physical Layer of the LTE standard with MATLAB® The LTE (Long Term Evolution) and LTE-Advanced are among the latest mobile communications standards, designed to realize the dream of a truly global, fast, all-IP-based, secure broadband mobile access technology. This book examines the Physical Layer (PHY) of the LTE standards by incorporating three conceptual elements: an overview of the theory behind key enabling technologies; a concise discussion regarding standard specifications; and the MATLAB® algorithms needed to simulate the standard. The use of MATLAB®, a widely used technical computing language, is one of the distinguishing features of this book. Through a series of MATLAB® programs, the author explores each of the enabling technologies, pedagogically synthesizes an LTE PHY system model, and evaluates system performance at each stage. Following this step-by-step process, readers will achieve deeper understanding of LTE concepts and specifications through simulations. Key Features: • Accessible, intuitive, and progressive; one of the few books to focus primarily on the modeling, simulation, and implementation of the LTE PHY standard • Includes case studies and testbenches in MATLAB®, which build knowledge gradually and incrementally until a functional specification for the LTE PHY is attained • Accompanying Web site includes all MATLAB® programs, together with PowerPoint slides and other illustrative examples Dr Houman Zarrinkoub has served as a development manager and now as a senior product manager with MathWorks, based in Massachusetts, USA. Within his 12 years at MathWorks, he has been responsible for multiple signal processing and communications software tools. Prior to MathWorks, he was a research scientist in the Wireless Group at Nortel Networks, where he contributed to multiple standardization projects for 3G mobile technologies. He has been awarded multiple patents on topics related to computer simulations. He holds a BSc degree in Electrical Engineering from McGill University and MSc and PhD degrees in Telecommunications from the Institut Nationale de la Recherche Scientifique, in Canada. www.wiley.com/go/zarrinkoub
Lte Advanced - Physical Layer Improvements
Author: Vincenzo MaltaPublisher: LAP Lambert Academic Publishing
ISBN: 9783844307931
Category : Long-Term Evolution (Telecommunications)
Languages : en
Pages : 108
Book Description
Orthogonal Frequency Division Modulation (OFDM) is the modulation employed by the LTE downlink physical layer. Recent studies on pilot-aided channel estimation, show that assuming a parametric channel model can effectively improve the estimate accuracy. The algorithms based on this model perform the frequency response estimation of a multipath environment through the knowledge of the tap-delay parameters. This work focuses on the estimation of the number of delays, required by the tap-delay estimators. For this purpose the state-of-the-art detection scheme is investigated over a static and a dynamic channel. Furthermore, it is compared with an approach based on a simple threshold operation. It s shown that over the static channel, MDL exhibits a certain robustness against the time observation reduction, while the Threshold algorithm suffers from a signi cant increase in the estimate s error. Tests over the dynamic channel show a general performances decrement. However MDL average error doesn t drastically get worse as the Threshold one. The state-of-the-art performances then, are not exceeded, but the noticed problems still leave this topic open.
Improved Synchronization and Channel Estimation Methods for Communication System
Author: Hui JinChannel Estimation Techniques for OFDM Systems in Dispersive Time-varying Channels
Author: Publisher:
ISBN:
Category :
Languages : en
Pages :
Book Description
Coherent modulation is more effective than differential modulation for orthogonal frequency division multiplexing (OFDM) systems requiring high data rate and spectral efficiency. Channel estimation is therefore an integral part of the receiver design. In this thesis, two iterative maximum likelihood based channel estimation algorithms are proposed for an OFDM system in dispersive time-varying channels. A multipath channel model is proposed for OFDM uplink transmission in macrocellular systems. The multipath fading channel is modeled such that the channel state can be determined by estimating the unknown channel parameters. A second-order Taylor series expansion is adopted to simplify the channel estimation problem. Based on the system model, an iterative maximum likelihood based algorithm is first proposed to estimate the discrete-time channel parameters. The mean square error performance of the proposed algorithm is analyzed using a small perturbation technique. Based on a convergence rate analysis, an improved iterative maximum likelihood based channel estimation algorithm is presented using a successive overrelaxation method. Numerical experiments are performed to confirm the theoretical analyses and show the improvement in convergence rate of the improved algorithm.