Journal ArticleDOI
ICI mitigation for pilot-aided OFDM mobile systems
Yasamin Mostofi,Donald C. Cox +1 more
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TLDR
This work introduces two new methods to mitigate ICI in an OFDM system with coherent channel estimation that use a piece-wise linear model to approximate channel time-variations and finds a closed-form expression for the improvement in average signal-to-interference ratio (SIR) when these mitigation methods are applied for a narrowband time-Variant channel.Abstract:Â
Orthogonal frequency-division multiplexing (OFDM) is robust against frequency selective fading due to the increase of the symbol duration. However, for mobile applications channel time-variations in one OFDM symbol introduce intercarrier-interference (ICI) which degrades the performance. This becomes more severe as mobile speed, carrier frequency or OFDM symbol duration increases. As delay spread increases, symbol duration should also increase in order to maintain a near-constant channel in every frequency subband. Also, due to the high demand for bandwidth, there is a trend toward higher carrier frequencies. Therefore, to have an acceptable reception quality for the applications that experience high delay and Doppler spread, there is a need for ICI mitigation within one OFDM symbol. We introduce two new methods to mitigate ICI in an OFDM system with coherent channel estimation. Both methods use a piece-wise linear model to approximate channel time-variations. The first method extracts channel time-variations information from the cyclic prefix. The second method estimates these variations using the next symbol. We find a closed-form expression for the improvement in average signal-to-interference ratio (SIR) when our mitigation methods are applied for a narrowband time-variant channel. Finally, our simulation results show how these methods would improve the performance in a highly time-variant environment with high delay spread.read more
Citations
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Journal ArticleDOI
OFDM and Its Wireless Applications: A Survey
TL;DR: This paper addresses basic OFDM and related modulations, as well as techniques to improve the performance of OFDM for wireless communications, including channel estimation and signal detection, time- and frequency-offset estimation and correction, peak-to-average power ratio reduction, and multiple-input-multiple-output (MIMO) techniques.
Journal ArticleDOI
Modulation Formats and Waveforms for 5G Networks: Who Will Be the Heir of OFDM?: An overview of alternative modulation schemes for improved spectral efficiency
Paolo Banelli,Stefano Buzzi,Giulio Colavolpe,Andrea Modenini,Fredrik Rusek,Alessandro Ugolini +5 more
TL;DR: This article provides a review of some modulation formats suited for 5G, enriched by a comparative analysis of their performance in a cellular environment, and by a discussion on their interactions with specific 5G ingredients.
Channel Estimation in OFDM Systems
TL;DR: In this article, two major types of pilot arrangement such as block type and comb-type pilot have been focused employing Least Square Error (LSE) and minimum mean square error (MMSE) channel estimators.
Journal ArticleDOI
A Survey on High Mobility Wireless Communications: Challenges, Opportunities and Solutions
Jingxian Wu,Pingzhi Fan +1 more
TL;DR: A systematic review of high mobility communications, which focuses primarily on physical layer operations, which are affected the most by the mobile environment, and comprehensive reviews of techniques that can address these challenges and utilize the unique opportunities.
Journal ArticleDOI
Vehicular Communications: A Physical Layer Perspective
TL;DR: In this paper, the authors discuss fundamental physical layer issues that enable efficient vehicular communications and present a comprehensive overview of the state-of-the-art research in vehicular communication.
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