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1answer
22 views

Manual Extraction of Filter Phase Response with MATLAB using sweep sine

I'm currently at a loss for why my code seems to not be working. I'm doing a sine sweep on a filter to calculate its freq and phase response. The frequency response checks out, however the phase ...
0
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1answer
31 views

Phase is not linear in frequency domain after delay in time domain

When impulse response is symmetric around sample zero phase entirely zero. in = 0 , 0 , 0 , 0 , 1 , 1 , 1 , 1 , 0 , 0 , 0 -> This gives zero phase result As I know if I apply a delay in time ...
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2answers
49 views

Phase response of FFT in practice

As I know if the impulse response is symmetric around sample zero phase response should be entirely zero. The code below just set a rectangular window for vector "in" ...
0
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0answers
19 views

Amplitudes and phases of transform of an image

I have recorded an image of a large macromolecule and after several types of image analysis, have obtained a rotationally averaged image, that is not quite perfect, but appears to show 6-fold ...
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2answers
33 views

Deconvolve a symmetric sequence into minimum-phase and maximum-phase sequences

I learned in school that any real-valued, even-symmetric sequence can be expressed as the convolution of a minimum-phase sequence and its time-reverse, which is maximum-phase. In my case, the ...
0
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1answer
80 views

Phase difference between two sinuisoidal signal

Currently, I have two signals, the main components of both signals are 60Hz, but both also have weaker response at 180Hz + small amount of noise. As shown in the photo below, I want to find the phase ...
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3answers
90 views

In filter design, why isn't it possible to have a frequency response with phase 0?

A linear phase filter will cause a delay in the output signal of the filter. If I'm not mistaken, a filter with phase equal 0 would cause no delays in the output signal. Can someone explain me why ...
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0answers
8 views

How can the Lock In amplifier give an output that have many frequencies?

I know that the Lock In amplifier locks into the reference frequency using some correlation methods. This way, we get the in-phase (and sometimes the out-of-phase) signal. According to this, for ...
0
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1answer
44 views

retrieve phase of an extrapolated periodic 1D signal

I have a periodic signal on a given grid, say (in matlab format): ...
0
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1answer
49 views

Phase Estimation in speech enhancement

I am reading a recent paper titled "Phase Estimation of Speech Enhancement - unimportant, important, or impossible?" by Grekmann et al. published in the 2012 the IEEE convention. The paper proposes an ...
0
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0answers
77 views

Image processing: Importance of phase

I was doing some experiment on image processing. I wanted to explore the importance of phase and Magnitude. I followed the following approach: Take 2 image of same dimension. Apply Fourier ...
0
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1answer
89 views

Tutorial for a stereo Phaser in C++?

I was searching for a tutorial on how to implement a stereo Phaser in C++. All i´ve found was sourcecode with little or no explanations which did´nt help me much. Does anyone know a Tutorial with ...
0
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1answer
48 views

Help me understanding this source code of a Phaser

I tried to understand the following source code of a Phaser: ...
1
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1answer
78 views

3 Band Crossover with Linkwitz Riley Filter

I would like to write a 3 Band "EQ" with BiQuad Filters but for some reason, I get some phase distortion. The problem already got discussed here. I found out that I need to work with Allpass filters ...
1
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1answer
45 views

the phase spectrum of a zero-phase wavelet is not zero!

I am going to plot the phase spectrum of a zero-phase ricker wavelet. I calculate the fft of the wavelet and use the phase or ...
0
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0answers
15 views

Magnitude and Phasor Response of Direct Form 1

i want to draw the magnitude and phasor response of the given equation H(Z) = (0.0605 +0.121z^-1 + 0.0605z-2)/(1-1.194z-1 + 0.436z-2) i need Matlab code and also explain that how will i draw in my ...
0
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0answers
56 views

For discrete signals, why does phase change not correspond to time shift?

I'm going through a Signal Processing lecture where the professor mentions this fact and the argument given is: Suppose you have a sinusoidal signal: $Acos(\omega t)$ Now if you change the phase of ...
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0answers
22 views

calculate signal power for windowed sine like signal while ignoring phase shift

What is the best way to calculate the signal power of a sine like signal, recorded into a small buffer (32 samples), in such a way that phase shifts of a few samples will not have an influence on the ...
1
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2answers
70 views

Validating cross corrolation between sine and cos, shouldn't pahse lag be pi/2?

I am trying to use cross correlation instead of FFT to find lags between 2 signals. I am trying to understand cross correlation by using it on sin and cos and expecting phase lag to be pi/2 but it is ...
0
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1answer
106 views

How to find phase difference between 2 signals, one has an unknown function

I have a system that is forced by a sinusoidal function with specific amplitude, phase and frequency ( all these are known ahead of time). I get a deformation of sinusoidal form as well (think of a ...
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0answers
31 views

Phase difference betwen 2 signals, 1 signal with unknown function

I understand this question may have been addressed however I have a major difference. I started out with a sinusoid of form A*sin(2 pi freq t + phase) and I know ...
0
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0answers
10 views

Is there a 3-dimensional correlate to phase residues?

In 2D phase unwrapping problems, the presence of a "phase residue" indicates that the answer obtained from a path-following unwrapping algorithm is dependent upon the path taken. A phase residue is a ...
0
votes
1answer
56 views

Instantaneous phase calculation problems

I am currently struggling with a problem when calculating the instantaneous phase of a wavefield using a 1D Hilbert transformation. The scheme is as follows. 1D Hilbert transformation of wave field ...
0
votes
1answer
45 views

Phase angle operator, Implemention and drawbacks

Let assume we have a signal as: $\color{blue} {x(t)=M e^{(-\beta.t)} e^{j(\sigma .t+\delta )}}$ By applying phase angle operator we have: $\color{blue} {Phase[x(t)]=Phase[M e^{-\beta.t} e^{j(\sigma ...
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0answers
20 views

Testing whether instantaneous phase algorithm works 2D

I need to calculate the instantaneous phase $\phi$ of a 2D wave field $U$ in C which can be derived by one of two 1D Hilbert transforms $H$: $$ q(x,z) = H_1[U(x,z)] = 1/\pi \int_R U(x-\zeta,z) ...
0
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1answer
53 views

How to calculate the time delay of a signal by a first-order filter

lets assume following signal $$x=a_1 \sin(2\pi f_1 t) + a_2 \sin(2\pi f_2 t).$$ This is passed through a simple single-pole filter with cut-off frequency $f_c$. How is $x$ delayed by the filter (peak ...
3
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2answers
209 views

Using Goertzel Algorithm in under-sampling

I plan to calculate a signal's phase using Goertzel Algorithm. I have 2 signals coming to microcontroller's ADC. Need to measure the phase difference between them. Signals are 15MHz sinusoids. Sample ...
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0answers
109 views

Convolving two complex signals - relationship between phase

Suppose two continuous complex domain signals are convolved, how is the magnitude and phase of the resultant signal related to the magnitudes and phase of the original signals?
-1
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1answer
163 views

once again,confusion between phase and group delay [duplicate]

Despite,reading up on this I'm unable to find crystal clear clarity on the differences b/w phase and grpdelay functions and interpretation of grpdelay's output. I have designed a low pass butterworth ...
1
vote
1answer
39 views

How are phase values able to capture motion from video?

I know that the phase spectrum contains most of the structural information about the image importance of phase. But I want to know more about importance of phase spectrum related to video signals. I ...
1
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0answers
34 views

Remove phase mis-alighnment in digital signals

Apologies for the poorly formulated question -- I've been away from DSP for a while. Let us say I have amplitude vs time data for N signals. where amplitude is -127 to 127. For each signal I have say ...
1
vote
2answers
139 views

Compensate for phase shift of Hilbert transform

I'm using Octave and trying to use the "instfreq" function from the time frequency toolbox which requires an analytic signal input. To get this analytic signal I'm using the Octave function "hilbert" ...
1
vote
1answer
50 views

Is phase and amplitude information necessarily lost when undersampling?

Is phase and amplitude information necessarily lost when undersampling if you have a constant periodic single frequency sinusoidal? My second question is: How can one determine the undersampling ...
0
votes
1answer
69 views

Phase reference of a periodic signal

Assume an arbitrary (discrete) signal that is periodic and known over a whole period. I need a way to select a characteristic point along the signal such that I can always retrieve it even when the ...
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0answers
87 views

Doppler shift using PLL

I am trying to apply phase lock loop to calculate phase shift due to doppler effect and finally calculate the doppler frequency($\Delta f$). I am assuming that the received wave is of the form, $r(t) ...
2
votes
1answer
307 views

How does time shift correspond to phase change in a discrete signal?

I was watching this video where the presenter remarks: For a discrete signal, time shift corresponds to phase change in a discrete signal but not vice versa. I was trying to figure out how ...
0
votes
1answer
37 views

How to check if Fourier components are in phase of out of phase?

I have a time series (of 23 timestamps) of which I take the Fourier transform. Now the fourier transform has 23 imaginary values and each has an amplitude and a phase. When I get the phase angle, it ...
0
votes
1answer
66 views

matlab's FFT is wrong? don't think so

i'm trying to get an FFT of a signal my FFT has 1024 samples i added two sin functions one of freq 86,13Hz (2*44100/1024) and one of freq 129,19Hz (3*44100/1024) the WAV looks like that (for 1 ...
1
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0answers
39 views

Importance of phase of time-series for PSD

I have $m$ complex-valued time-series $z_m(t_n)$, which I am currently analyzing. I started by calculating their PSDs and CSDs. These exhibit an unexpected peak at a given frequency, which is present ...
2
votes
2answers
155 views

Minimum phase systems with pole at infinity

If a system is given by a transfer function in the z domain that has all poles and zeros inside the unit circle except for a factor of $z^{-1}$ in the denominator (pole at infinity), can it still be ...
1
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2answers
234 views

problems calculating phase propagation (in C)

I'm coding a phase vocoder in C for time-stretching audio signals. The only piece that is currently not working is the phase propagation. I take overlapping frames from an input signal, apply a ...
1
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0answers
132 views

Audio Steganography using Phase Encoding Technique

I referred the below papers to understand the working of Phase Encoding,but the explanation is not proper.Just a few steps have been given in brief. ijcsi.org www.ijarcce.com Can someone please ...
0
votes
1answer
37 views

Obtaining the frequency and phase spectra from fourier transform?

For a question on my homework, I am given f(t) = e^(-a*abs(t)) and asked to find the Fourier transform of the function. I understand how to do that part, but then ...
1
vote
0answers
66 views

Derive Maximum of zero phase rotated wavelet from rotated wavelet

I have one question concerning phase rotation of signals and I am not sure wether it works or not: Let's assume we have a zero-phase wavelet x(t) i.e. Ricker wavelet. Unfortunately, in our ...
2
votes
1answer
69 views

Digital Vs. Analog Phase measurement [closed]

I'm working on a Ultrasonic Transducers resonance tracking system. Where phase shift between Voltage and Current is the feedback signal for my system when phase difference is Zero that means system is ...
2
votes
2answers
127 views

How do you alter the phase relationship between I and Q in a quadrature signal?

I am collection a quadrature signal from a radio. The I and Q signals go through a sound card at a sample rate of 192000, and then a FFT is performed on the signals. Due to various reasons, the ...
3
votes
1answer
148 views

proving that a log gabor filter has 0 DC offset

I have read somewhere online that the log gabor filter has an advantage over the gabor filter, in the sense that it has 0 DC component. How do you prove this property mathematically? Thanks in ...
3
votes
3answers
423 views

Can a causal filter without phase shifts exist?

When I was studying dispersion of refraction index in semiconductors and dielectrics, my professor tried to explain that if a filter (like a dielectric absorbing some light frequencies, or an electric ...
2
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2answers
721 views

Carrier frequency offset (CFO) estimation using cyclic prefix

I understand the cyclic prefix, but in (1) it's said that: "If we consider that the channel effect is minimal and can be neglected. then the phase difference of the CP and the OFDM symbol which the ...
2
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2answers
753 views

Effect of Hanning Window on phase of FFT

I'm calculating the beat of song through the frequency domain. I have 60 seconds of audio sampled at 48000Hz, multiplied by a Hanning window in the time domain. This gives me a resolution in the ...