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0answers
5 views

Trending work on phase locked loop in optical communication

I am just researching more on PLL and its use in several different ways. I have gone through the basics, PLL as demodulator and phase detector and coherent detector and few more..... In IEEE i can ...
0
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0answers
26 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
33 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
37 views

Help me understanding this source code of a Phaser

I tried to understand the following source code of a Phaser: ...
1
vote
1answer
39 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
22 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 ...
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0answers
14 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
37 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 ...
0
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0answers
21 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
60 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
62 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 ...
0
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0answers
28 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
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1answer
43 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 ...
-1
votes
1answer
38 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 ...
0
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0answers
18 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
43 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 ...
2
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2answers
151 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 ...
2
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0answers
94 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
124 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 ...
0
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1answer
35 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
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2answers
101 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
44 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
58 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 ...
2
votes
0answers
72 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
202 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
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1answer
34 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
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1answer
61 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
38 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 ...
1
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2answers
101 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
vote
2answers
212 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
95 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
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1answer
35 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
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0answers
53 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
68 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
106 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
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1answer
125 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
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3answers
311 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
546 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
587 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 ...
6
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2answers
1k views

baffled by fft phase spectrum!

A very simple MATLAB experiment: f = 200; fs = 1000; t = 0: 1/fs : 1; x = cos(2*pi*f*t); plot(angle(fftshift(fft(x)))); And here's the output: Now, ...
0
votes
2answers
71 views

how to make fft ignore phase shift when only interested in magnitude

I have a signal that consists of a sine wave, on which I apply a rectangular window and then an FFT. I'm only interested in the magnitude of the sine wave, and I want it to stay the same even if the ...
1
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0answers
47 views

transmitting data using phase modulation of two sine waves passed through distortion

I have two sine signals with frequencies f1 and f2, and phase p1 and p2. I modulate the phase of these signals to transmit two symbols simultaneously, chosen from the set [0,1,2,3]. For example, I ...
0
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1answer
95 views

Change of bin magnitude when phase of signal changes when doing FFT?

I am working on an implementation in which I need to apply an FFT to determine which of 4 frequencies are present in a signal. I am doing a 64 point FFT on a buffer which only is partly filled (the ...
5
votes
1answer
216 views

Removing a sinusoidal artifact from a set of movie frames

I am doing some post-hoc analysis of a dataset consisting of a series of movie frames that are contaminated by a strongly periodic artifact. I would like to remove this artifact from my frames. For ...
1
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3answers
140 views

What does the term phase actually mean?

I am new to seismic data processing and I really have no understanding of the term 'phase'. So, could anybody give me a simple explaination of the term? Thank you
0
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1answer
92 views

Comparing the loudness of two samples

I have two wave files each containing a sample of a note. I wish to compare, using a program, each sample and present how loud the first sample is with respect to the second if each sample is played ...
0
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1answer
132 views

Phase factors for an 32 point fft

I have just started working on FFT and its related phase factors. I have read for an N=2 point FFT, We have two phase factors, one on the positive axis and one on negative axis. similarly for an 4 ...
1
vote
1answer
278 views

Time shifts and change in phase

My question here is in regards to implicit information/terminology. Basically, whenever we say that "a shift in time means a change of phase in fourier space", is it implicit that the shift is ...