Filter bank multicarrier (FBMC) has been developed as an alternative to overcome the drawbacks of orthogonal frequency-division multiplexing (OFDM) in certain areas, especially for improved spectral efficiency and errorless communication under doubly dispersive channel conditions. The prototype filters in FBMC systems must satisfy dual orthogonality conditions and be well localized in both time and frequency domains; hence have to be analysed in both dimensions. Ambiguity function is a two-dimensional function of time and frequency, which is the correlation between the filter coefficients and its frequency-modulated versions. In the present study, a matrix formulation of discrete ambiguity function generation is derived based on which the prototype filters for FBMC and OFDM are analysed and compared in terms of time frequency localization, dual orthogonality criterion, side-lobe levels in time and frequency, signal-to-interference ratio, constellation diagram concentration, and bit error rate plots. FBMC systems prove to be better than OFDM in all these criteria. Copyright © 2015 by the IETE.

Ramachandra Reddy G

Department of Communication Engineering

School of Electronics Engineering

Vellore Campus

Vellore Institute of Technology (VIT) is a private university located in&nbsp;Tamil Nadu, India. Founded in 1984, as Vellore Engineering College, the institution offers 20 undergraduate, 34 postgraduate, four integrated and four research programs. It has campuses in Vellore, Amravati, Bhopal and Chennai.

VIT is one of the top ranked private universities in India according to NIRF, THE and QS Rankings.&nbsp;Govt. of India has recognized&nbsp;VIT, Vellore as an&nbsp;Institution of Eminence. This has allowed VIT to take independent quality initiatives and move up in world ranking.

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VIT University

Discrete Ambiguity Function Based Analysis of Filter Bank Multicarrier Systems

IETE Technical Review

Filter bank multicarrier (FBMC) has emerged as the favourite multicarrier communication technique since it meets the demands of the next-generation standards, especially for communication under doubly dispersive channels. In order to combat the undesirable channel effects like inter symbol interference and inter carrier interference, the prototype filters used in FBMC systems must satisfy orthogonality conditions and be well localized simultaneously in both time and frequency domains. Even though conventional doubly localized filters are optimum in the absence of channel, they fail to satisfy orthogonality and localization criteria under doubly dispersive channels. In the present study, an adaptive filter design method is proposed in which the prototype filter is designed as the weighted sum of a time-limited Nyquist filter, a band-limited Nyquist filter, and doubly localized Gaussian filter based on the analysis of discrete ambiguity function (DAF). The filter is designed to vary its characteristics according to the maximum time and frequency domain dispersions of the channel, so that signal-to-interference ratio is maximized. In order to ensure distortion-less transmission, the perfect reconstruction criterion for distortion-less transmission is mapped to specific conditions for DAF according to two-dimensional channel scattering function. The superiority in performance of the proposed adaptive filter is analysed in terms of signal-to-interference ratio and bit error rate, and is compared with the conventional filters for various channel scattering conditions. © 2018, © 2018 IETE.

IETE Journal of Research

Novel Adaptive Filter Design for Filter Bank Multicarrier System Under Doubly Dispersive Channel Conditions

Filter Bank Multicarrier (FBMC) is emerging as a better alternative to the Orthogonal Frequency Division Multiplexing (OFDM) in next generation wireless multicarrier systems. For robust performance under doubly dispersive channels, the prototype filter in FBMC systems must be isotropic and orthogonal in time and frequency. The existing design methods for prototype filter design are the Extended Gaussian Function (EGF) design based on Zak transform and Weighted HermitePulse (WHP) design. In this paper, it is attempted to design the prototype filter by performing time frequency analysis on the Ambiguity function of isotropic Hermite pulses. The Filter coefficients are obtained as the weighted sum of the Hermite pulses and constrained optimization is performed to find out the weights. An alternative objective function and optimization procedure is used in the present study which yield better results compared to conventional WHP problem. The orthogonality and isotropic conditions of the designed filter is compared with the conventional filters using Ambiguity plots. © 2013 IEEE.

2013 International Mutli-Conference on Automation, Computing, Communication, Control and Compressed Sensing (iMac4s)

Efficient prototype filter design for Filter Bank Multicarrier (FBMC) System based on Ambiguity function analysis of Hermite polynomials

2014 IEEE 10th International Conference on Wireless and Mobile Computing, Networking and Communications (WiMob)

Performance comparison of CP-OFDM and OQAM-OFDM systems based on LTE parameters

IEEE Transactions on Circuits and Systems I: Regular Papers

Hardware Architecture of IOTA Pulse Shaping Filters for Multicarrier Systems

Review of Space-time Coded Orthogonal Frequency Division Multiplexing Systems for Wireless Communication

Journal	IETE Technical Review
Publisher	Informa UK Limited
ISSN	0256-4602
Open Access	0