scholarly journals Real-time digital signal recovery for a low-pass transfer function system with multiple complex poles

2018 ◽  
Author(s):  
Jhinhwan Lee
Keyword(s):  
Transfer Function ◽  
Real Time ◽  
Digital Signal ◽  
Signal Recovery ◽  
Pass Filter ◽  
Low Pass Filter ◽  
Recovery Method ◽  
Noise Characteristics ◽  
Resonance Frequencies ◽  
Low Pass

In order to solve the problems of waveform distortion and signal delay by many physical and electrical systems with linear low-pass transfer characteristics with multiple complex poles, a general digital-signal-processing (DSP)-based method of real-time recovery of the original source waveform from the distorted output waveform is proposed. From the convolution kernel representation of a multiple-pole low-pass transfer function with an arbitrary denominator polynomial with real valued coefficients, it is shown that the source waveform can be accurately recovered in real time using a particular moving average algorithm with real-valued DSP computations only, even though some or all of the poles are complex. The proposed digital signal recovery method is DC-accurate and unaffected by initial conditions, transient signals, and resonant amplitude enhancement. The noise characteristics of the data recovery shows inverse of the low-pass filter characteristics. This method can be applied to most sensors and amplifiers operating close to their frequency response limits or around their resonance frequencies to accurately deconvolute the multiple-pole characteristics and to improve the overall performances of data acquisition systems and digital feedback control systems.

scholarly journals Real-Time Digital Signal Recovery for a Low-Pass Transfer Function System with Multiple Complex Poles

2018 ◽  
Author(s):  
Jhinhwan Lee
Keyword(s):  
Transfer Function ◽  
Real Time ◽  
Initial Conditions ◽  
Digital Signal ◽  
Signal Recovery ◽  
Signal Delay ◽  
Recovery Method ◽  
Resonant Amplitude ◽  
Resonance Frequencies ◽  
Low Pass

In order to solve the problems of waveform distortion and signal delay by many physical and electrical systems with linear low-pass transfer characteristics with multiple complex poles, a general digital-signal-processing (DSP)-based method of real-time recovery of the original source waveform from the distorted output waveform is proposed. From the convolution kernel representation of a multiple-pole low-pass transfer function with an arbitrary denominator polynomial with real valued coefficients, it is shown that the source waveform can be accurately recovered in real time using a particular moving average algorithm with real-valued DSP computations only, even though some or all of the poles are complex. The proposed digital signal recovery method is DC-accurate and unaffected by initial conditions, transient signals, and resonant amplitude enhancement. This method can be applied to most sensors and amplifiers operating close to their frequency response limits or around their resonance frequencies to accurately deconvolute the multiple-pole characteristics and to improve the overall performances of data acquisition systems and digital feedback control systems.

ANALYSIS AND IMPROVEMENT TECHNIQUES FOR THE TRANSFER FUNCTION OF A PLANAR LOW - PASS FILTER

2016 ◽  
Vol 15 (12) ◽  
pp. 2579-2586
Author(s):  
Adina Racasan ◽  
Calin Munteanu ◽  
Vasile Topa ◽  
Claudia Pacurar ◽  
Claudia Hebedean
Keyword(s):  
Transfer Function ◽  
Pass Filter ◽  
Low Pass Filter ◽  
Low Pass

Rapid Recovery of Wide-Bandwidth Photothermal Signals via Homodyne Photothermal Spectrometry: Theory and Methodology

1993 ◽  
Vol 47 (4) ◽  
pp. 489-500 ◽  
Author(s):  
J. F. Power ◽  
M. C. Prystay
Keyword(s):  
High Frequency ◽  
Low Cost ◽  
Signal Recovery ◽  
Wide Bandwidth ◽  
Pass Filter ◽  
Low Pass Filter ◽  
Filter Output ◽  
Low Pass ◽  
Four Quadrant ◽  
Lock In

Homodyne photothermal spectrometry (HPS) is a very wide bandwidth signal recovery technique which uses many of the elements of lock-in detection at very low cost. The method uses a frequency sweep, with a high-frequency bandwidth of up to 10 MHz, to excite a linear photothermal system. The response sweep of the photothermal system is downshifted into a bandwidth of a few kilohertz by means of in-phase mixing with the excitation sweep with the use of a four-quadrant double-balanced mixer and a low-pass filter. Under conditions derived from theory, the filter output gives a good approximation to the real part of the photothermal system's frequency response, dispersed as a function of time. From a recording of this signal, the frequency and impulse response of the photothermal system are rapidly recovered at very high resolution. The method has been tested with the use of laser photopyroelectric effect spectrometry and provides an inexpensive, convenient method for the recovery of high-frequency photothermal signals.

scholarly journals Study of modular transfer function-based optieal low-pass filter evaluation model and experiment

2008 ◽  
Vol 57 (5) ◽  
pp. 2854
Author(s):  
Qi Xun-Jun ◽  
Lin Bin ◽  
Cao Xiang-Qun ◽  
Chen Yu-Qing
Keyword(s):  
Transfer Function ◽  
Evaluation Model ◽  
Pass Filter ◽  
Low Pass Filter ◽  
Low Pass

Norepinephrine reuptake, baroreflex dynamics, and arterial pressure variability in rats

2000 ◽  
Vol 279 (4) ◽  
pp. R1257-R1267 ◽  
Author(s):  
Delphine Bertram ◽  
Christian Barrès ◽  
Yong Cheng ◽  
Claude Julien
Keyword(s):  
Time Delay ◽  
Transfer Function ◽  
Fixed Time ◽  
Baroreceptor Reflex ◽  
Pass Filter ◽  
Low Pass Filter ◽  
Mayer Waves ◽  
Frequency Responses ◽  
Low Pass ◽  
Norepinephrine Reuptake

This study examined the effect of norepinephrine reuptake blockade with desipramine (DMI) on the spontaneous variability of the simultaneously recorded arterial pressure (AP) and renal sympathetic nerve activity (SNA) in conscious rats. Acute DMI administration (2 mg/kg iv) depressed AP Mayer waves (∼0.4 Hz) and increased low-frequency (<0.2 Hz) components of AP variability. DMI decreased renal SNA variability, especially due to the abolition of oscillations related to Mayer waves. To examine whether DMI-induced changes in AP and renal SNA variabilities could be explained by alterations in the dynamic characteristics of the baroreceptor reflex loop, the frequency responses of mean AP to aortic depressor nerve stimulation were studied in urethan-anesthetized rats. DMI accentuated the low-pass filter properties of the transfer function without significantly altering the fixed time delay. The frequency responses of iliac vascular conductance to stimulation of the lumbar sympathetic chain were studied in an additional group of anesthetized rats. DMI did not markedly alter the low-pass filter properties of the transfer function and slightly increased the fixed time delay. These results suggest that the DMI-induced decrease in the dynamic gain of the baroreceptor reflex is responsible for the decreased spontaneous renal SNA variability and the accompanying increased AP variability. The “slowing down” of baroreflex responses cannot be attributed to an effect of DMI at the vascular neuroeffector junction.

Parietal Representation of Hand Velocity in a Copy Task

2005 ◽  
Vol 93 (1) ◽  
pp. 508-518 ◽  
Author(s):  
Bruno B. Averbeck ◽  
Matthew V. Chafee ◽  
David A. Crowe ◽  
Apostolos P. Georgopoulos
Keyword(s):  
Transfer Function ◽  
Linear Model ◽  
Parietal Cortex ◽  
Neural Activity ◽  
Nonlinear Models ◽  
Linear Representation ◽  
Pass Filter ◽  
Low Pass Filter ◽  
Filter Width ◽  
Low Pass

We recorded neural activity from ensembles of neurons in areas 5 and 2 of parietal cortex, while two monkeys copied triangles, squares, trapezoids, and inverted triangles and used both linear and nonlinear models to predict the hand velocity from the neural activity of the ensembles. The linear model generally outperformed the nonlinear model, suggesting a reasonably linear relation between the neural activity and the hand velocity. We also found that the average transfer function of the linear model fit to individual cells was a low-pass filter because the neural response had considerable high-frequency power, whereas the hand velocity only had power at frequencies below ∼5 Hz. Increasing the width of the transfer function, up to a width of 700–800 ms, improved the fit of the model. Furthermore, the Rsqr of the linear model improved monotonically with the number of cells in the ensemble, saturating at 60–80% for a filter width of 700 ms. Finally, it was found that including an interaction term, which allowed the transfer function to shift with the eye position, did not improve the fit of the model. Thus ensemble neural responses in superior parietal cortex provide a high-fidelity, linear representation of hand kinematics within our task.

scholarly journals Real-Time Filter Method Based on the Structural Frequency of FAST Cabin-Cable System

2014 ◽  
Vol 6 ◽  
pp. 129302
Author(s):  
Wenhua Xu ◽  
Hong Bao ◽  
Jianwei Mi ◽  
Guigeng Yang
Keyword(s):  
Real Time ◽  
Fundamental Frequency ◽  
Variable Structure ◽  
Measured Data ◽  
Filter Method ◽  
Great Flexibility ◽  
Cable System ◽  
Pass Filter ◽  
Low Pass Filter ◽  
Low Pass

Due to great flexibility, low damping, and variable structure in the cabin-cable system of five hundred meter Aperture Spherical Radio Telescope (FAST), a real-time digital low-pass filter based on the analysis of frequency is presented in this paper. Firstly, by the Lomb-Scargle theorem, it can obtain the fundamental frequency of cabin-cable system. Then, using the obtained frequency, a digital low-pass filter is designed to filter the measured data. After being filtered, the measured data are used for coarse control. Finally, the results of the experiments on the FAST 5 m model show that calculating the fundamental frequency is accurate and the filter is effective.

LC-Resonant and High-Temperature Resistant Acceleration Sensor Based on DSP

2011 ◽  
Vol 105-107 ◽  
pp. 1966-1969
Author(s):  
Tao Guo ◽  
Jie Zhu ◽  
Gui Tang ◽  
Yan Xu
Keyword(s):  
High Temperature ◽  
High Speed ◽  
Space Shuttle ◽  
Digital Signal ◽  
Acceleration Sensor ◽  
Pass Filter ◽  
Low Pass Filter ◽  
Analog To Digital ◽  
Acceleration Sensors ◽  
Low Pass

It is a challenging problem to test the acceleration of the high-speed missiles and space shuttle under high temperature. This paper proposed a design of LC-resonant and high-temperature resistant acceleration sensors about the phenomenon. With the operational amplifier OP4177, it produces the input signal that contents with A/D (Analog to Digital) signal. An eight level low-pass filter MAX291 is used for testing after the signal is regulated. This design mainly uses AD7934 to complete the conversion from analog signals to digital signals. It also recognizes the resonant point of LC acceleration sensor by the DSP （Digital Signal Processing）recognizing program. The acceleration is computed finally by the DSP chip.

Digital All-Pass Filter Modeling Based on Desired Group Delay Using Advanced Material: A Review on the Signal Processing Part

2015 ◽  
Vol 815 ◽  
pp. 338-342
Author(s):  
Faizah Abu Bakar ◽  
Sohiful Anuar Zainol Murad ◽  
Rizalafande Che Ismail ◽  
Muzamir Isa
Keyword(s):  
Transfer Function ◽  
Group Delay ◽  
Sampling Frequency ◽  
Bilinear Transformation ◽  
Pass Filter ◽  
Low Pass Filter ◽  
Phase Type ◽  
Low Pass ◽  
Group Delays ◽  
Delay Variation

This paper presents a review on three types of techniques in designing digital all-pass filters based on group delay. All the three methods use the same basic concept rooting back to the requirement of a stable transfer function of the filter which should be a minimum-phase type, and the denominator group delay. The most optimized of the three is chosen to be implemented in MATLAB in order to decrease the group delay variation of a 5th order Chebyshev low-pass filter with cut-off frequency of 160 MHz. The digital transfer function of the low-pass filter is obtained from the analog transfer function by means of bilinear transformation. The sampling frequency of the digital LPF is 100 times the cut-off ffrequency to retain the response of the analog LPF. Both of the filters are then cascaded together and the overall group delays variations are analyzed. The variations of group delay shows a reduction but the price paid is the increase of the overall group delay of the system.

Sign in / Sign up

Export Citation Format

Share Document