The Experts below are selected from a list of 294 Experts worldwide ranked by ideXlab platform

Sanjit K. Mitra - One of the best experts on this subject based on the ideXlab platform.

  • Frequency estimation using warped Discrete Fourier Transform
    Signal Processing, 2003
    Co-Authors: Stefan Franz, Sanjit K. Mitra, Gerhard Doblinger
    Abstract:

    As a complement to the periodogram, low-cost frequency estimators are of interest. In this paper we introduce a new approach for single frequency estimation using the warped Discrete Fourier Transform (WDFT). The WDFT corresponds to sampling the z-Transform of a finite length sequence at warped points in the frequency domain by using an allpass function which allows to increase the frequency resolution locally. We focus on a first-order allpass function with a complex valued warping parameter. If the warping parameter is zero, the WDFT reduces to the Discrete Fourier Transform. Performance and complexity aspects of the proposed algorithm are discussed and finally, we provide an perspective on how the WDFT can be used to reduce the complexity of existing estimators in the case of multiple sinusoids.

  • The Nonuniform Discrete Fourier Transform
    Nonuniform Sampling, 2001
    Co-Authors: Sonali Bagchi, Sanjit K. Mitra
    Abstract:

    In many applications, when the representation of a Discrete-time signal or a system in the frequency domain is of interest, the Discrete-Time Fourier Transform (DTFT) and the z-Transform are often used. In the case of a Discrete-time signal of finite length, the most widely used frequency-domain representation is the Discrete Fourier Transform (DFT), which is simply composed of samples of the DTFT of the sequence at equally spaced frequency points, or equivalently, samples of its z-Transform at equally spaced points on the unit circle. A generalization of the DFT, introduced in this chapter, is the Nonuniform Discrete Fourier Transform (NDFT), which can be used to obtain frequency domain information of a finite-length signal at arbitrarily chosen frequency points. We provide an introduction to the NDFT and discuss its applications in the design of 1-D and 2-D FIR digital filters. We begin by introducing the problem of computing frequency samples of the z-Transform of a finite-length sequence. We develop the basics of the NDFT, including its definition, properties and computational aspects. The NDFT is also extended to two dimensions. We propose NDFT-based nonuniform frequency sampling techniques for designing 1-D and 2-D FIR digital filters, and present design examples. The resulting filters are compared with those designed by other existing methods.

  • the nonuniform Discrete Fourier Transform and its applications in signal processing
    1998
    Co-Authors: Sonali Bagchi, Sanjit K. Mitra
    Abstract:

    1. Introduction. 2. The Nonuniform Discrete Fourier Transform. 3. 1-D Fir Filter Design Using the NDFT. 4. 2-D Fir Filter Design Using the NDFT. 5. Antenna Pattern Synthesis with Prescribed Nulls. 6. Dual-Tone Multi-Frequency Signal Decoding. 7. Conclusions. References. Index.

K.m.m. Prabhu - One of the best experts on this subject based on the ideXlab platform.

  • Estimation of frequency offset using warped Discrete-Fourier Transform
    Signal Processing, 2006
    Co-Authors: Ramji Venkataramanan, K.m.m. Prabhu
    Abstract:

    In this paper, the problem of estimating a small frequency offset in a signal with a large carrier frequency is addressed. The warped Discrete-Fourier Transform (WDFT) [A. Makur, S.K. Mitra, IEEE Trans. Circuits Systems--I: Fundam. Theory Appl. 6 (9) (September 2001) 1086-1093] is used and the accuracy of estimation and computational complexity of this technique is compared with the conventional Discrete-Fourier Transform (DFT) and the nonuniform Discrete-Fourier Transform (NDFT). A numerical example is provided to illustrate the comparison.

V.v.b. Rao - One of the best experts on this subject based on the ideXlab platform.

Gerhard Doblinger - One of the best experts on this subject based on the ideXlab platform.

  • Frequency estimation using warped Discrete Fourier Transform
    Signal Processing, 2003
    Co-Authors: Stefan Franz, Sanjit K. Mitra, Gerhard Doblinger
    Abstract:

    As a complement to the periodogram, low-cost frequency estimators are of interest. In this paper we introduce a new approach for single frequency estimation using the warped Discrete Fourier Transform (WDFT). The WDFT corresponds to sampling the z-Transform of a finite length sequence at warped points in the frequency domain by using an allpass function which allows to increase the frequency resolution locally. We focus on a first-order allpass function with a complex valued warping parameter. If the warping parameter is zero, the WDFT reduces to the Discrete Fourier Transform. Performance and complexity aspects of the proposed algorithm are discussed and finally, we provide an perspective on how the WDFT can be used to reduce the complexity of existing estimators in the case of multiple sinusoids.

Olga Ponomareva - One of the best experts on this subject based on the ideXlab platform.

  • Digital signal processing in telecommunications based on parametric Discrete Fourier Transform
    ITM Web of Conferences, 2019
    Co-Authors: Olga Ponomareva, Alexey Ponomarev, Natalya Smirnova
    Abstract:

    A generalization of the Discrete Fourier Transform in the form of a parametric Discrete Fourier Transform is proposed. The analytical and stochastic properties of the introduced Discrete Transformation are investigated. An example of the application of the parametric Discrete Fourier Transform in telecommunications is given - a generalization of the well-known Herzel algorithm

  • Sliding signal processing in telecommunication networks based on two-dimensional Discrete Fourier Transform
    ITM Web of Conferences, 2019
    Co-Authors: Vladimir Ponomarev, Olga Ponomareva, Alexey Ponomarev, Natalya Smirnova
    Abstract:

    A method of vertical sliding processing of two-dimensional Discrete signals in the spatial frequency domain is proposed — a method of fast vertically sliding two-dimensional Discrete Fourier Transform. The mathematical representation of the two-dimensional Discrete Fourier Transform in algebraic and matrix form is considered. An effective method of vertically sliding two-dimensional Discrete Fourier Transform is proposed. The algorithm developed in the framework of the proposed method allows calculating the coefficients (bins) of this Transformation in real time.

  • evolution of forward and inverse Discrete Fourier Transform
    East-West Design and Test Symposium, 2018
    Co-Authors: Olga Ponomareva, Alexey Ponomarev, Vladimir Ponomarev
    Abstract:

    The problems of the evolution of the forward and inverse Discrete Fourier Transform are investigated. Forward and inverse Discrete Fourier Transform is the basis of the classical Discrete spectral analysis of signals. The effectiveness of known methods for modifying the original Discrete signal is analyzed to improve the characteristics of classical Discrete spectral analysis of signals. A generalization of the Discrete Fourier Transform (DFT) in the form of a parametric Discrete Fourier Transform (DFT-P) is proposed, which, in essence, is the evolution of the Discrete Fourier Transform. A generalization of the inverse Discrete Fourier Transform (IDFT) is given in the form of a modified parametric Discrete Fourier Transform (MDFT-P). The basic properties of the bases of DFT-P and MDPF-P are presented. The interrelation between the methods of modifying the original Discrete signal and the parametric DFT and the modified parametric DFT is considered.

  • window presum parametric Discrete Fourier Transform
    East-West Design and Test Symposium, 2018
    Co-Authors: Olga Ponomareva, Alexey Ponomarev, Natalia Ponomareva
    Abstract:

    The article gives an analysis of the advantages and disadvantages of the original method for implementing a practical spectrum analyzer based on the Discrete Fourier Transform (DFT). There are two names used for this method: the weighted overlap-add structure, and the window-presum FFT method. It is shown that the main disadvantage of the weighted superimposition-addition method is the fixation of the central frequencies of the filters of the realized spectrum analyzer. The theoretical foundations of this method have been discovered and investigated. It is shown that the reason for the disadvantage of the method is the procedure used for preliminary data processing in the time domain. Based on the analysis of the DFT matrix, it is shown that the preprocessing procedure used in the time domain is only one of the possible procedures. A generalization of the weighted superposition-addition (FFT method with preliminary summation) is proposed on the basis of a parametric Discrete Fourier Transform.

  • EWDTS - Evolution of Forward and Inverse Discrete Fourier Transform
    2018 IEEE East-West Design & Test Symposium (EWDTS), 2018
    Co-Authors: Olga Ponomareva, Alexey Ponomarev, Vladimir Ponomarev
    Abstract:

    The problems of the evolution of the forward and inverse Discrete Fourier Transform are investigated. Forward and inverse Discrete Fourier Transform is the basis of the classical Discrete spectral analysis of signals. The effectiveness of known methods for modifying the original Discrete signal is analyzed to improve the characteristics of classical Discrete spectral analysis of signals. A generalization of the Discrete Fourier Transform (DFT) in the form of a parametric Discrete Fourier Transform (DFT-P) is proposed, which, in essence, is the evolution of the Discrete Fourier Transform. A generalization of the inverse Discrete Fourier Transform (IDFT) is given in the form of a modified parametric Discrete Fourier Transform (MDFT-P). The basic properties of the bases of DFT-P and MDPF-P are presented. The interrelation between the methods of modifying the original Discrete signal and the parametric DFT and the modified parametric DFT is considered.