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Wei Jin - One of the best experts on this subject based on the ideXlab platform.

Massimiliano Laddomada - One of the best experts on this subject based on the ideXlab platform.

  • design of efficient multiplierless modified cosine based Comb decimation Filters analysis and implementation
    IEEE Transactions on Circuits and Systems I-regular Papers, 2017
    Co-Authors: Gordana Jovanovic Dolecek, Jose Ricardo Garcia Baez, Massimiliano Laddomada
    Abstract:

    This paper presents a computationally efficient design of modified cosine-based decimation Filters. One of the main contributions of this paper is the proposal of a multiplierless finite impulse response low-order linear-phase filter to increase spurious signal rejection in the so-called folding bands. The resulting Filters feature reduced computational complexity compared with other recent proposals in the literature, as well as higher folding-band attenuation than traditional Comb Filters. The frequency behavior of the proposed class of decimation Filters is compared with generalized Comb Filters as well as other proposals in the recent literature. Moreover, this paper addresses field-programmable gate array implementation of the proposed Filters in a variety of structures, including both nonrecursive and recursive architectures, and it evaluates and compares the performance of these architectures in terms of area and power consumption. A critical comparison is provided with the goal of highlighting key design issues and computational efficient implementations for the interested reader.

  • design of two stage nonrecursive rotated Comb decimation Filters with droop compensation and multiplierless architecture
    Journal of The Franklin Institute-engineering and Applied Mathematics, 2015
    Co-Authors: Jovanovic G Dolecek, Massimiliano Laddomada
    Abstract:

    Abstract This paper proposes a class of decimation Filters with reduced passband signal distortion and improved spurious signal rejection across the folding bands. These Filters are well-suited to decimation of oversampled digital signals processed by wideband digital receivers and Σ Δ AD converters. The total decimation factor is split between two stages of decimation and zero rotation in a nonrecursive form is applied at the lower rate in order to reduce the computational complexity of the proposed Filters. We also address a framework to implement multiplierless Filters and to compensate for the passband droop introduced by this class of Filters. For increased flexibility, we generalize the transfer function by allowing different orders between the two stages of decimation. The paper presents many examples to clearly describe the design procedure. Comparisons are also given with the goal of contrasting the magnitude responses of the proposed Filters with the ones of three other techniques recently proposed in the literature, as well as with classical Comb Filters.

  • Optimal Sharpening of Compensated Comb Decimation Filters: Analysis and Design
    TheScientificWorldJournal, 2014
    Co-Authors: David Ernesto Troncoso Romero, Massimiliano Laddomada, Gordana Jovanovic Dolecek
    Abstract:

    Comb Filters are a class of low-complexity Filters especially useful for multistage decimation processes. However, the magnitude response of Comb Filters presents a droop in the passband region and low stopband attenuation, which is undesirable in many applications. In this work, it is shown that, for stringent magnitude specifications, sharpening compensated Comb Filters requires a lower-degree sharpening polynomial compared to sharpening Comb Filters without compensation, resulting in a solution with lower computational complexity. Using a simple three-addition compensator and an optimization-based derivation of sharpening polynomials, we introduce an effective low-complexity filtering scheme. Design examples are presented in order to show the performance improvement in terms of passband distortion and selectivity compared to other methods based on the traditional Kaiser-Hamming sharpening and the Chebyshev sharpening techniques recently introduced in the literature.

  • efficient design of two stage Comb based decimation Filters using chebyshev sharpening
    International Midwest Symposium on Circuits and Systems, 2013
    Co-Authors: David Ernesto Troncoso Romero, Gordana Jovanovic Dolecek, Massimiliano Laddomada
    Abstract:

    A simple and efficient method to design multiplierless two-stage Comb-based decimation Filters is presented. The proposed scheme takes advantage of the Chebyshev sharpening, recently introduced in literature, to obtain higher selectivity in comparison to traditional Comb Filters. The resulting filter has better magnitude response characteristics and fewer Additions Per Output Sample (APOS) with respect to other two-stage Comb-based Filters available in literature.

  • a novel two stage nonrecursive architecture for the design of generalized Comb Filters
    Digital Signal Processing, 2012
    Co-Authors: Gordana Jovanovic Dolecek, Massimiliano Laddomada
    Abstract:

    This paper presents a novel two-stage class of decimation Filters with superior spurious signal rejection performance around the so-called folding bands, i.e., frequency intervals whose signals get folded down to baseband due to decimation. The key idea to enhance signal rejection in the frequency domain lies on an effective way to place the zeros of a classical Comb filter in the aforementioned folding bands. On the other hand, the paper provides a mathematical framework for designing two-stage multiplierless and nonrecursive structures of the proposed Filters. Examples are provided to highlight the key steps in the design of the proposed Filters. Moreover, the frequency behavior of the proposed Filters in both baseband and stopband is compared with classical and generalized Comb Filters, and a droop compensator is proposed to counteract the passband distortion of the proposed Filters.

Jin W - One of the best experts on this subject based on the ideXlab platform.

  • Tunable Comb Filters and refractive index sensors based on fiber loop mirror with inline high birefringence microfiber
    Optical Society of America, 2013
    Co-Authors: Xuan H, Wang C, Jin W
    Abstract:

    Highly birefringent (Hi-Bi) microfiber-based fiber loop mirrors (FLMs) were studied for tunable Comb Filters and refractive index (RI) sensors. The use of two cascaded Hi-Bi microfibers instead of a single microfiber allows more flexibility in controlling the transmission/reflection characteristics of the FLM. The length of Hi-Bi microfibers is of the order of centimeters, one or even more than two orders of magnitude shorter than the conventional Hi-Bi fiber-based FLM devices. The transmission/reflection spectra are sensitive to the RI surrounding the microfibers, and RI sensitivity of 20,745 nm/RIU was experimentally demonstrated.Department of Electrical Engineerin

  • Birefringent microfiber-based fiber loop mirrors for tunable Filters and refractive index sensors
    SPIE-International Society for Optical Engineering, 2013
    Co-Authors: Hf Xuan, Jin W
    Abstract:

    Fifth European Workshop on Optical Fibre Sensors, Krakow, Poland, 19-22 May 2013Highly birefringent (Hi-Bi) microfiber-based fiber loop mirrors (FLMs) were studied for tunable Comb Filters and refractive index (RI) sensors. RI sensitivity of up to 15,441 nm/RIU was experimentally demonstrated for the RI sensors and, for the tunable filter a thermal tuning coefficient of ~-2.35nm/°C was obtained for temperature from 20 to 90°C when it was immersed into water. The use of two cascaded Hi-Bi micro-tapers within a Sagnac loop allows more flexibility in controlling the transmission/reflection spectraums of the FLM. The length of the tapered Hi-Bi microfibers is on the order of centimeters, two orders of magnitude shorter than the conventional Hi-Bi fiber-based devices. © (2013) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.Department of Electrical EngineeringRefereed conference pape

Wa Jin - One of the best experts on this subject based on the ideXlab platform.

Gordana Jovanovic Dolecek - One of the best experts on this subject based on the ideXlab platform.

  • methods for improving magnitude characteristic of Comb decimation Filters
    2018
    Co-Authors: Gordana Jovanovic Dolecek
    Abstract:

    This chapter presents some recent proposed methods to improve the magnitude characteristic of Comb Filters in stopband, passband, as well as in both passband and stopband. First, the methods for aliasing rejection improvement based on exploring the characteristics of symmetrical polynomials are presented. In that way the alias rejection in Comb folding bands can be increased in a simple way without introducing multipliers. More precisely, the zeros of Comb filter can be rotated from their original positions to other positions inside the folding bands, by appropriately changing the coefficients of the transfer function of cascaded Combs. In the following the methods for Comb passband droop compensation in a wideband are presented, based on trigonometrical approach, in which the magnitude responses of compensators are in sinusoidal forms. The parameters of compensators are amplitudes of sinusoidal functions which depend on the number of the cascaded Comb Filters. The resulting compensators are multiplierless and work at low rate and provide a good Comb compensation in a wide passband. Finally, the method based on multiplierless corrector Filters for improvement of Comb magnitude characteristic in passband, as well as in folding bands, is elaborated. The methods are illustrated with examples, and MATLAB scripts are provided for presented methods.

  • design of efficient multiplierless modified cosine based Comb decimation Filters analysis and implementation
    IEEE Transactions on Circuits and Systems I-regular Papers, 2017
    Co-Authors: Gordana Jovanovic Dolecek, Jose Ricardo Garcia Baez, Massimiliano Laddomada
    Abstract:

    This paper presents a computationally efficient design of modified cosine-based decimation Filters. One of the main contributions of this paper is the proposal of a multiplierless finite impulse response low-order linear-phase filter to increase spurious signal rejection in the so-called folding bands. The resulting Filters feature reduced computational complexity compared with other recent proposals in the literature, as well as higher folding-band attenuation than traditional Comb Filters. The frequency behavior of the proposed class of decimation Filters is compared with generalized Comb Filters as well as other proposals in the recent literature. Moreover, this paper addresses field-programmable gate array implementation of the proposed Filters in a variety of structures, including both nonrecursive and recursive architectures, and it evaluates and compares the performance of these architectures in terms of area and power consumption. A critical comparison is provided with the goal of highlighting key design issues and computational efficient implementations for the interested reader.

  • novel two stage Comb decimator with improved frequency characteristic
    Latin American Symposium on Circuits and Systems, 2015
    Co-Authors: Gerardo Molina Salgado, Gordana Jovanovic Dolecek, Jose M De La Rosa
    Abstract:

    This paper presents a novel low-power two-stage Comb-based decimator in which the passband droop is decreased and the attenuation in all odd folding bands are increased. This is achieved by using simple corrector filter and the sharpening technique in the second stage. The only design parameter is the number of the cascaded Comb Filters K in the first stage. However, the second stage remains the same for all values of the parameter K. The proposed method is compared with the similar methods in the open literature. FPGA implementation proves that the proposed structure has improved characteristics at the cost of an increase of 33.3% in power consumption, compared with the Comb.

  • MULTIPLIER-FREE FILTER DESIGN USING LT Comb Filters
    2014
    Co-Authors: Gordana Jovanovic Dolecek, Vlatko Dolecek, Bosnia Herzegovina
    Abstract:

    This paper present on simple method for multiplier-free finite impulse response (FIR) filter design based on the cascade of Comb and linearly tapered Comb Filters. The stopband frequency determines the length of the Comb filter. The method is used for narrowband Filters where the passband frequency is not more than 0.1 of the stopband frequency. The sharpening technique is used to satisfy the desired stopband attenuation and the minimum passband ripple

  • an overview of decimator structures for efficient sigma delta converters trends design issues and practical solutions
    International Symposium on Circuits and Systems, 2014
    Co-Authors: Gerardo Molina Salgado, Gordana Jovanovic Dolecek, Jose M De La Rosa
    Abstract:

    Classical decimation structures usually use Comb Filters at first stage due to the simplicity of Comb Filters. However, Comb Filters cannot satisfy high performance demands of state-of-the-art Sigma-Delta (ΣΔ) analog-digital converters (ADCs). Some possible solutions are Comb based structures which are power and area efficient and posses an improved magnitude characteristic. The principal issues in the Comb-based filter design are: power and area efficiency, high alias rejection and approximately flat passband characteristic, considering also high values of the decimation factors. In this paper we first review the new trends in ΣΔ ADCs and demands for the decimation block design. Next we review power and area efficient structures. The methods to improve the alias rejection of Comb Filters, as well as the methods for the compensation for the Comb passband droop, and those strategies which simultaneously improve the alias rejection and the passband droop are reviewed in the following. Finally we review the multirate decimation structures.