Low Pass FIR Filter Research Articles

Merenje komponenti električne snage po standardu IEEE 1459-2010

In this paper, the design and implementation of a novel recursive method for the power measurement ac-cording to the IEEE Standard 1459-2010 have been described. The most important parts are adaptive band and low-pass FIR filters that extract fundamental and dc components, respectively. In addition, by using oversampling techniques and decimation filters, coefficient sensitivity problems of the large-order FIR comb cascade structure are overridden and the parameter estimation accuracy is improved. The symmetrical components are estimated through a transformation matrix of adaptive phase shifters. The effectiveness of the proposed techniques is demonstrated by simulation results.

Design, comparison and analysis of low pass FIR filter using window techniques method

In digital communication, a filter is any device that selectively attenuates any unwanted component from a received signal. It essentially changes or reshapes the waveform of a signal in the desired manner. In this work, we have designed and studied low pass filter using Rectangular, Bartlett, Hamming, Hanning, Tukey and Kaiser Window algorithms and compared them with each other for further analysis. The parameters we used for designing the filter are sampling frequency, cut off frequency, filter order and a variable parameter, α. MATLAB toolbox for DSP, namely FDA Tool and FV Tool were employed for the realization of the design.

Design a Suitable Optimized Low Pass FIR Filter for Ultrasonic Signal

Sensors play a vital role in the human life, so it is very important to improve their output signals. One of the most known sensors is ultrasonic sensor. The mentioned sensor uses simple principle to measure a distance between it and nearest obstacle. The output of this sensor improved in this work using FIR filter. The FIR filter parameters are calculated based on Genetic Algorithm (GA). The simulated results using MATLAB show that the optimized filtered data is more suitable and effective to use in many applications.

Design of narrow transition band variable bandwidth digital filter

This study presents a novel implementation technique for linear phase variable bandwidth finite impulse response (FIR) filters with a noticeable reduction in transition bandwidth as well as hardware complexity. In this proposition, concept of Farrow structure based design technique is effectively utilised; whereas the fixed sub-filters are constructed from a generalised interpolated bandpass method based low-pass FIR filter by means of different techniques such as interpolation, up-sampling and masking. Simulation results have shown the frequency response characteristics of several variable bandwidth FIR filters, designed with the help of the proposed architecture. Simulation results have shown a drastic reduction of transition bandwidth resulting from the proposed variable bandwidth FIR filters of up to ∼70–80%, when compared with other state-of-the-art filtering techniques, with a significant reduction in hardware complexity of up to ∼50%.

Flexible bandwidth reduction technique for envelope tracking using low‐pass finite impulse response filters

In this Letter, low-pass finite impulse response filters are proposed to flexibly reduce the envelope bandwidth (BW) requirements for envelope tracking (ET) supply modulators. A second-order power ET (PET) approach is used as a comparative study, and a `design zone' for shaping function coefficients is identified for the first time. Proposed 20 and 10 MHz low-pass filters (LPFs) are used to reduce the effective envelope BW in response to a 20 MHz long-term evolution signal applied to a 10 W power amplifier (PA). Experimental results verify that in comparison with PET, the proposed LPF method has the benefit of allowing arbitrary BW reduction and is compatible with the use of customised shaping functions. It is also shown that significant memory effects can be introduced when the effective envelope BW is reduced to less than the RF BW. To investigate the linearisability of the ET PA, the linearity before and after digital pre-distortion is also measured.

Minimization of SIDELOBE Attenuation and Power of a Fir Low Pass Filter using FRFT and CSD Algorithm

For digital signal processing, communication systems and VLSI design architectures, an efficient FIR filter is required to eliminate the noise signals. To design an efficient FIR filter, the minimization of two parameters is required such as side lobe attenuation and power. These two parameters can be achieved by designing a FIR filter with the help of Fractional Fourier Transform (FrFT) and Canonical Signed digit (CSD) algorithm. In this work, Finite Impulse Response (FIR) low pass filter is designed by using both FrFT and ordinary Fourier Transform (FT) methods and their frequency responses are compared in terms of side lobe attenuation (SLA). After comparison of both methods, the better results are obtained for an FrFT based design of FIR low pass filter. Apart from this, the FrFT based design of FIR low pass filter is realized in direct form architecture and implemented in VLSI. Further, the Canonical Signed digit (CSD) algorithm is applied for the multiplication process in the architecture implementation to minimize the power consumption. Moreover, frequency response of FIR low pass filter is obtained by using MATLAB software and simulation and synthesis results are obtained by using Xilinx 13.1 ISE.

Variable cutoff frequency FIR filters: a survey

Many signal processing applications require digital filters with variable frequency characteristics, especially the filters with variable bandwidth. Due to their linear phase and inherent stability, variable bandwidth finite impulse response (FIR) filters are the popular choice in majority of the applications. Once a variable cutoff frequency (VCF) FIR lowpass filter is designed, variable bandwidth bandpass / highpass / bandstop filters and reconfigurable filter banks can be realized from the same. In this paper, we present a comprehensive review of the existing variable cutoff frequency FIR filter design techniques, including the developments in the recent two decades. We provide the basic concepts, design and architectural details for each of these techniques and the major developments / incremental works thereof. Qualitative as well as quantitative comparisons are provided to assist the reader in choosing the most suitable VCF filter design technique for a particular application.

Signal Filter Cut-Off Frequency Determination to Enhance the Accuracy of Rail Track Irregularity Detection and Localization

A continuous condition monitoring system to detect and localize railroad track irregularities is achievable with inertial sensors onboard revenue service trains. However, the inaccurate geospatial position estimates of GPS receivers and the non-uniform sampling of inertial sensors adds noise and reduces signal strength. Consequently, the signal-to-noise ratio decreases, which leads to higher rates of false positives and false negatives. Appropriate signal filtering, alignment, and combination from multiple traversals can enhance the signal-to-noise ratio. However, it is not straightforward in determining the best cut-off frequency for the filter. This paper introduces a method that is suitable for any signal filtering approach. The frequency window of the resultant energy and variance of ensemble averaged FFTs informs the best cut-off frequency. The results affirm that a low-pass finite impulse response filter with the selected cutoff frequency progressively increases the signal-to-noise ratio with increasing filter order, thus demonstrating the effectiveness and practicality of the method.

A Design of a low-pass FIR filter using Hamming Window Functions in Matlab

The reduction and filtering of the input components of an original signal in one or more frequency bands using a finite impulse response, better known as FIR, is designed using a function of the Hamming window. Although there are various window functions such as the Blackman window function, the Hanning window function and the rectangular window functions that can be used as digital filters, the Hamming window function was used in this study for the reason of its minimum damping/decibel of the stopband with a reduced transition bandwidth. Among the other three widow functions that can be used, the Blackman window function is closest to the Hamming window function in terms of minimum bandstop attenuation/decibel, since both have a dB value greater than -50. However, in terms of transition bandwidth (Δω), the Hamming window has a narrower bandwidth than the Blackman window, making it more appropriate to use in this FIR filter design. This type of filter is important for analyzing the different types of signals that are essential in a world where digital filters play a major role in DSP applications. This research paper offers a Matlab-based low-pass FIR digital filter that uses Hamming window functions. Keywords: FIR filters, Hamming window, Blackman window Hanning window, Matlab. DOI: 10.7176/CEIS/11-2-04 Publication date: February 29 th 2020

Robust Analytical Design of Optimal Equiripple Lowpass FIR Filters

For the first time, an analytical design of optimal equiripple lowpass finite impulse response filters is presented. An analytical filter design, which is based on formulas, stands in contrast to the Parks-McClellan approach which is based on a numerical optimization. An advantage of evaluating impulse response coefficients using formulas over a numerical optimization is the robustness of the analytical design. Equiripple filters are optimal in terms of a minimal filter length for an arbitrary filter specification. The novel design is based on an equiripple approximating polynomial which approximates two constants in two disjoint intervals in optimal equiripple sense. A recursive formula for evaluating the impulse response of the filter is also introduced. The algorithm provides not only robust formulas for evaluating the impulse response, but also an analytical view on its coefficients. An example demonstrates the efficiency of the design. Its superiority in terms of robustness over the Parks-McClellan approach is emphasized.

Digital spotlighting filtering optimization for SAR imaging

In this paper, a synthetic aperture radar (SAR) image formation simulator is used to objectively evaluate the parameter selection within the digital spotlighting process. Specifically, recommendations for the filter type and filter order of the low-pass filters used in the range and azimuth decimation processes within the digital spotlighting algorithm are determined to maximize image quality and minimize computational cost. Results show that a finite impulse response low-pass filter with a Taylor (overline {n}=5) window applied provides the highest image quality over a wide range of filter orders and decimation factors. Additionally, a linear relationship between filter length and decimation factor is found.

Design of Narrow Transition Band Digital Filter: An Analytical Approach

Frequency response masking (FRM) approach, is widely used to reduce the transition width of FIR filter which includes several advantages like lower coefficient sensitivity, higher computation speed and low power consumption. This paper proposes a novel interpolated bandpass method (IBM) for the synthesis of linear phase, narrow transition band FIR filter with less complexity. Simulation results have shown the magnitude response of several lowpass FIR filters with narrow transition bandwidth, as designed with the aid of proposed approach. Supremacy of the proposed algorithm has also been established in terms of frequency response characteristics and hardware complexity over a number of state-of-the-art techniques of recent interest. Simulation results have identified an improvement of ∼18.89%, 44.62%, 38.75%, 41.2% and 29.5% in terms of transition bandwidth when compared with several example filters under consideration. In addition to this, hardware cost resulting from the proposed narrow-band FIR filter is analyzed by implementing it on Artix field programmable gate array (FPGA) chip and consequently power consumption of the resulting filter has been estimated using Xilinx Power Estimator (XPE)-2018.1. Finally, the designed narrow transition band FIR filter is used in filtered-orthogonal frequency division multiplexing (F-OFDM) based quadrature amplitude modulated (QAM) system and the resultant bit error rate (BER) performance has been studied.

Energy Efficient and High–Performance FIR Filter Design on Spartan–6 FPGA

In this paper, we are going to design the energy efficient Gaussian low pass FIR filter on spartan-6 FPGA. To make an energy efficient filter, we have used different methods in this paper like capacitance scaling, frequency scaling, and then we analysed the demand of power by Gaussian low pass FIR filter. The frequency range which is used in this paper is 1 GHz, 2GHz, 2.5GHz, 5 GHz, 10 GHz and the range of capacitance which we have used un this paper is 5pF, 10pF, 25pF, 40pF and 50 pF. An FIR filter always remnants in linear phase with the help of symmetric co-efficient and this is the very useful feature of the FIR filter for phase sensitive application like data communications etc. At present there are many different methods for communications and networking. So, in this paper, we have designed an energy efficient FIR filter and that design will faster than traditional design.

Energy Efficient FIR Filter for Biomedical Application using FPGA

This research work proposes a low power Finite Impulse Response (FIR) digital filter system using Field Programmable Gate Array (FPGA) to filter biomedical signals. A major issue regarding such implementations is associated with computational complexity that may hinder its practical application. Several researches that aim to overcome this problem have been found by using various designs like booth multiplier, distributive arithmetic design, reduce adder graph (RAG), common sub-expression elimination method etc. This work has achieved the target of power line frequency of 50Hz noise cancellation. It is shown that the proposed design using RAG can give faster speed and require less hardware resources than that for the Direct Structure-I design. The performance of the proposed method is also compared with several existing research works to study its efficacy and it is shown that proposed design can achieve nearly 2% area delay product and 43% less power consumptions in implementation of an FIR low-pass filter. The designed filter is also tested on ECG waves as example of biomedical signal from samples of the MIT-BIH Arrhythmia database corrupted with power frequency noise. The entire system has been implemented on the ALTERA DE-II FPGA education board by synthesizing Verilog HDL using Quartus II tool.

Design of Minimum-Phase FIR Filter: An Evolutionary Approach

In this communication, one novel attempt has been made towards the design of minimum-phase finite impulse response (FIR) filter using one evolutionary computation technique, named differential evolution (DE) algorithm. Mean square error (MSE) between the frequency samples of the ideal filter and the designed filter in the pass-band and stop-band region and the minimum average error (MAE) between the frequency samples in the transition-band region had been considered for the formulation of the objective function in the optimization process. Performance of the optimization technique has been monitored in terms of convergence characteristics for four different orders of FIR filter under consideration. Robustness of our proposition has been firmly established in the sense that the proposed algorithm can be suitably tuned for the design of low-pass, high-pass or band-pass FIR filter of different specifications. Supremacy of the proposed algorithm over other existing techniques for the design of minimum-phase FIR filter has been substantiated by means of frequency response and pole-zero diagrams.

Computing efficiency of the three-stage interpolated low pass filters

Undoubted advantages of finite impulse response filters are their unconditional stability, the absence of limit cycles and the possibility of implementing a filter that does not introduce phase distortion. The disadvantage of such filters is the large cost required to compute the response. This paper considers three-stage interpolated finite impulse response low-pass filters. The maximum values of the interpolation factors are determined. Dependences of the coefficient of computational efficiency and the coefficient of increase in the registers of the three-stage interpolated low-pass filter on the values of the interpolation factors, the widths of the passband and the transition band are obtained. Relations for determining the optimal values of interpolation factors corresponding to the maximal value of computational efficiency coefficient are obtained. In addition, the dependencies of the maximum coefficient of computational efficiency and the optimal coefficient of increase in the registers of the three-stage interpolated low-pass filter on the widths of the passband and the transition band at the optimum values of the interpolation factors are obtained. Considered three-stage interpolated low-pass filters should be used in the case when the required stopband is significantly less than the sampling rate. In this case, three- stage interpolated filters require less computational resources for calculating the response than the two-stage interpolated filters or filter implemented by the transversal structure.

Innovative technologies in vascular surgery

The aim — to search for new diagnostic and therapeutic directions in vascular surgery and study their technologies via experimental and clinical researches.Materials and methods. 1) The temperature during electric welding of biological tissues ranged from 4 to 146 °C, the average operating temperature during the welding process was 88.4 0C. The noise filtering was performed using noise filter functions and a LowPass FIR filter with the 20 Hz frequency. Histological specimens were studied using the Olympus BX 51 microscope, the Olympus C5050 Z digital camera, and the Olympus DP­Soft software. 2) MRI was performed in order to determine the actual shape of the vessels. For the reconstruction of their spatial shape, 3D image reconstruction software MRI Invesalins was used. The solid model of the artery was created using a laser 3D printer. Graph­analytical methods were used to describe the shape of the compressed artery. 3) The polymorphism of the NOS3 gene (the single nucleotide genetic polymorphism (SNP) in the human reference sequence — rs1799983) and the polymorphism of the CRAT gene (SNP in the reference human sequence — rs2296771) were identified by real­time polymerase chain reaction. The amplification of a corresponding region of DNA with a standard set of primers using the phenomenon of energy transfer using fluorescence resonance (FRET) was conducted in order to identify the polymorphic alleles.Results and discussion. 1) The electrowelding of the artery wall between the electrodes formed a seam, which consisted of a dense semitransparent tissue of light brown color with a clear boundary along the edge of the electrodes location. Microscopically, the substance of the electrowelding seam was represented by a homogeneous dense substance, which consisted of coagulated and strongly interconnected protein structures of vessel wall collagen fibers. 2) 3D reconstruction of the cervical arteries was performed using the 3D image reconstruction program MRI Invesalins, which objectively displayed the condition of the vertebral artery at the site of its narrowing. Reconstruction of the spatial shape of the artery made it possible to create the artery solid model using a laser 3D printer. 3) Based on the results of the genetic studies, a group of patients with a predisposition to develop endothelial and mitochondrial dysfunction was identified, where Tivorel (4.2 g arginine hydrochloride + 2.0 g L­carnitine) was used. Endothelial function in this group of patients was assessed by the magnitude of flow mediated vasodilatation (FMD), which reflects the ability of the brachial artery to dilatate in response to ischemia induced hyperaemia. The use of L­arginine resulted in a statistically significant increase in the flow mediated vasodilatation (FMD), which indicated the restoration of impaired endothelial function.Conclusions. 1) The strength of the tissue connection in electric welding seam depends on the degree of the tissue homogenization. 2) Graphical 3D modeling of pathologically narrowed arteries and computer data processing of MRI of the vessels allows determining the localization, character and spatial characteristics of the artery extravasal compression. Graph­analytical methods for describing the arterial shape became the theoretical basis for a new method of the artery extravasal compression studying. 3) The basis of personalized treatment in patients with ischemic tissue lesions is the conduction of genetic studies. Especially the determination of single nucleotide genetic polymorphisms (SNP) of the NOS3 gene, that is responsible for the synthesis of the protein «endothelial nitric oxide synthase» (rs1799983), and gene CRAT, that is responsible for the synthesis of the protein «carnitine­O­acetyltransferase» (rs2296771), is needed. Identification of mutant homozygotes determines predisposition to endothelial and mitochondrial dysfunction of the vessels, the development of atherosclerosis, arterial hypertension, diabetes mellitus, and heart failure.

Equiripple Approximation of Low-Pass FIR Filters

For the first time, the existence and the nature of a generating polynomial of an equiripple low-pass finite impulse response (FIR) filter is presented. In terms of approximation theory, this achievement represents a polynomial approximation of two constants in two disjoint intervals in the equiripple sense which was missing in the approximation theory. In opposite to numerical solutions, the novel generating polynomial provides an insight into the nature of the approximation problem. Two demonstrations of approximating polynomials of equiripple low-pass FIR filters are included.

An efficient local operator-based Q-compensated reverse time migration algorithm with multistage optimization

Most existing [Formula: see text]-compensated reverse time migration ([Formula: see text]-RTM) algorithms are based on pseudospectral methods. Because of the global nature of pseudospectral operators, these methods are not ideal for efficient parallelization, implying that they may suffer from high computational cost and inefficient memory usage for large-scale industrial problems. In this work, we reported a novel [Formula: see text]-RTM algorithm — the multistage optimized [Formula: see text]-RTM method. This [Formula: see text]-RTM algorithm uses a finite-difference method to compensate the amplitude and the phase simultaneously by uniquely combining two techniques: (1) a negative [Formula: see text] method for amplitude compensation and (2) a multistage dispersion optimization technique for phase correction. To prevent high-frequency noise from growing exponentially and ruining the imaging results, we apply a finite impulse response low-pass filter using the Kaiser window. The theoretical analyses and numerical experiments demonstrate that this [Formula: see text]-RTM algorithm precisely recovers the decayed amplitude and corrects the distorted phase caused by seismic attenuation effects, and hence produces higher resolution subsurface images with the correct structural depth information. This new method performs best in the frequency range of 10–70 Hz. Compared with pseudospectral [Formula: see text]-RTM methods, this [Formula: see text]-RTM approach offers nearly identical imaging quality. Based on local numerical differential operators, this [Formula: see text]-RTM method is very suitable for parallel computing and graphic processing unit implementation, an important feature for large 3D seismic surveys.

FPGA based Synthesize of PSO Algorithm and its Area-Performance Analysis

Digital filters are the most significant part of signal processing that are used in enormous applications such as speech recognition, acoustic, adaptive equalization, and noise and interference reduction. It would be of great benefit to implement adaptive FIR filter because of self-optimization property, linearity and frequency stability. Designing FIR filter involves multi-modal optimization problems whereas conservative gradient optimization technique is not useful to design the filter. Hence, Particle Swarm Optimization (PSO) algorithm is more flexible and optimization technique based on population of particles in search space and alternative approach for linear phase FIR filter design. PSO improves the solution characteristic by giving a novel method for updating swarm’s position and velocity vector. Set of optimized filter coefficients will be generated by PSO algorithm. In this paper, PSO based FIR Low pass filter is efficiently designed in MATLAB and further Xilinx System Generator tool is used to efficiently design, synthesize and implement FIR filter in FPGA using SPARTEN 3E kit. For an example specifications, output of PSO algorithm is obtained that is set of optimized coefficients whose response is approximating to the ideal response. Hence, functional verification of the proposed algorithm has been performed and the error between obtained filter and ideal filter is minimized successfully. This work demonstrates the effectiveness of the PSO algorithms in parallel processing environment as compared to the Remez Exchange algorithm.