Questions tagged [phase]

A quantity representing the fraction of cycle of a periodic signal, usually represented as an angle.

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Phase spectrum interpretation

I have an analog signal alternatively captured by two probes. Sometimes the signal is periodic and depending on the physical conditions the two periodic signals might be in phase or out of phase. Also,...
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Varying phase shift between two signals

I have two microphones separated by a distance d placed in end-fire configuration. Audio input data was played from the front side (i.e corresponding to 0 degrees.) The data picked by microphone1 and ...
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Phase Response of $N$-th order Digital All-Pass Filter

I am having trouble reconciling my derivation of the phase response of an N-th order all-pass filter with those I am finding in the literature, and I figured someone here could help me. Real Version: ...
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Amplitude-and phasefunctions for a system

I am studying a course in signalanalysis and have run into som trouble with a exercise. I am to dimension the circuit below in such a way that the DC-amplification is 1 and that the frequencies $\...
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Self Quadratic Phase Coupling || What does it really tell us?

I am working on a beginner kind of project, and after processing some data and plotting a lot of bispectrum plots, I found out that a lot of them had peaks on the diagonal fx = fy (where fi denotes ...
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How to calculate the total time delay of a first order linear filter on a signal?

I have a non-periodic signal. I apply a first order linear IIR filter on it. The filter will introduce phase shift to the signal that will appear as a total time delay. Is there a formula I can use to ...
Crataegus's user avatar
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Can FFT tells us existance of same frequencies with different phases?

So I know that applying FFT on a time-domain signal, shows which frequency components exists and what amplitudes each frequency signal has. My question is, suppose the signal contains same frequency ...
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When joining two signals of different frequencies how do I find the phase shift that makes the join smooth?

I'm generating a sine wave and I want the second half of the signal to be in a different frequency. How do I find the phase shift I can apply to the second half so that the joining between the halves ...
Victor Basso's user avatar
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1D-Phase Unwrapping

I am new to signal processing and I am reading about 1D phase unwrapping Here is the paper that I am reading. It refers to x as the signal but then it shows in the graph the axis are origina phase in ...
makala's user avatar
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How to demodulate PM with signal faster than carrier?

I have a signal that is a periodic concatenation of truncated Lorentzians ($\frac{1}{1+x^2}$), like so: The exact shape of the signal is unimportant I guess. I can approximate it with its first few ...
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DSP: newbie not understanding z transform/complex sinusoidal frequency and phase

Im reading Will Pirkles Designing audio effect plugins book and I'm not sure if I'm understanding the z transform correctly. I got up to differential equations in college, but haven't done math in ...
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signal processing techniques for accurate phase measurement

I have two signals, $V\sin(\omega t)$ and $V\sin(\omega t+\theta)$. I need to find the value of theta with an accuracy of $0.05$ degrees. Can anybody suggest a method for phase difference ...
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Why Bluetooth 2 use pi/4-DQPSK instead of OQPSK?

From the peak to average power ratio point of view OQPSK is better than pi/4-DQPSK. What is the advantage of pi/4-DQPSK compare to OQPSK? Why Bluetooth 2 use pi/4-DQPSK instead of OQPSK?
agile's user avatar
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Phase Error Growth in Digital Mixer Signal

I am working on a code where digital mixing is to be performed for down-conversion of incoming signal. The mixer signal is created using the phase accumulation approach. However it was observed that ...
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Timing Jitter in PLLs

Regarding white (uncorrelated) and coloured (correlated) timing jitter. I know that for free-running oscillators (such as VCOs), various kinds of noise causes the jitter, for example (1/f) coloured ...
Amro Goneim's user avatar
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Why RHP zero phase is not 180° to 90°

The asymptotic phase behavior of an RHP zero is from 0 degrees to -90°, the mirror of an LHP zero. Graphically, I'm confused about why this is the case and the phase is not from +180° to +90°. See the ...
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can $e^{j\phi_0}$ be incorporated into the sine and cosine terms?

This is from "communication system" by Carlson fifth edition page 109: If transfer function of a channel be like this: $H(f)= Ae^{j\phi_0}e^{-j2\pi ft_g} $ and input to this system be: $x(t)=...
m-sh-shokouhi's user avatar
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Extraction of the phase lag form cross-correlation function

I would like to find out the phase offset that my signal contains at the receiver side. For this, I use the cross-correlation function, where I cross-correlate signal before and after matched filter. ...
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Phase relationship of cosine components in real signal using DFT

Background Info I have a real signal comprised of 8 frequencies 400Hz-680Hz in 40Hz increments. The signal is generated from 8 cosines of equal amplitude (A=1) and phase (Phase= 0rad), summed together....
Jacob Calvert's user avatar
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Adding phase noise to a signal results in amplitude variation on a constellation - whats the mistake? *plots inside*

I am attempting to add phase noise to a modulated signal. I am doing this by taking a phase noise mask (single sided 0 Hz to 1 MHz), which shows dBc values away from central value or reference value. ...
Villere_DSP's user avatar
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What is phase shift?

I'm reading about when a $H(z)$ system is min phase or max phase, and I get when a system is a min phase or max phase depending on the location of the zeroes. But I don't get at all the phase shift ...
Nyquist-er's user avatar
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How to perform a phase recovery for higher order modulation schemes

My objective is to demodulate the signals with different modulation orders and schemes. In particular, I want to recover the phase first. Let us say, my signal looks like in the constellation below . ...
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How to obtain the exact value of wavelength from a 2D FFT amplitude vs wavenumber plot like it is obtainable from 1D FFT amplitude vs wavenumber plot?

I have a two dimensional multi modal spatial signal generated from a MATLAB code using sinusoidal functions of different wave numbers, amplitudes and phases. What I want to know is that if I have the ...
Shataneek Banerjee's user avatar
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Performing root-music, how do i retrieve frequency and phase data of a signal?

I'm trying an alternative method to the classical fft to do signal analysis. I perform root-MUSIC on a certain known signal + noise in matlab with the function 'rootmusic'. This gives gives the signal ...
Joost Poelmans's user avatar
2 votes
1 answer
211 views

Phase of the sine signal by finding FFT of it in matalb using angle

I am using sine signal with phase=0 an frequency=100KHz. Computed FFT of it. Using angle function and multiplied the result with 180/pi; But getting 90.36 at 100KHz frequency. Can anybody explain why ...
user653241's user avatar
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1 answer
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What phase rotation occurs when you take the derivative of an audio signal?

If you take the derivative of an audio signal, it provides a 6 dB/oct upward sloping filter (increasing high frequencies / cutting low frequencies) all the way across the spectrum. What is the result ...
mike's user avatar
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Accurate phase calculation in sinusoidal linear regression?

I've been trying to work out a way to minimize the error in phase calculation. The underlying model is the following $$s(t) = \sum_{i=1}^{M} A_i\sin\left(\frac{2\pi t}{T_i} + \phi_i\right) + \...
Cifer's user avatar
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Is there a physical reason why phase should be uniformly distributed?

I was thinking a little about how signal phase might be distributed. Usually in such discussions I see people make the assumption that phase is uniformly distributed between $0$ and $2 \pi$. This only ...
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Best window before FFT ? (for a signal consisting of 2 tones used for phase measurement)

I am doing phase measurments by transmitting and receiving tones (100 kHz and 16 kHz simultaneously). I am transmitting the tones and receiving them, applying Blackman Harris window and doing FFT for ...
Kurtul's user avatar
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How to compute correct phase in FFT even after applying phase unwrap and zeroing round off error?

I am converting a time-domain synthetic 1D signal to frequency domain using MATLAB fft. In the frequency domain, the amplitude vs frequency plot is coming reasonable which means it is showing the ...
Shataneek Banerjee's user avatar
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Breaking down sin wave to frequency domain causing weirdness in phase

I have tried many many different things and I cannot figure out why my phase is messed up. Here is what I am trying to do. I create a simple signal with a known wavelength, phase, and amplitude like ...
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Creating Bode Plot from Experimental Data

I have a blackbox system in which I can input a function and obtain the output signal (in MATLAB). I'm attempting to reconstruct a Bode diagram and have had success with the Magnitude plot, however, I'...
migeve3630's user avatar
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Phase correction algorithm: minimisation phase error

Thank you for your participation in my discussion in advance. I am working on the implementation of a phase correction. Currently, I have finished the algorithm. I think it is a standard algorithm ...
Jang Lee's user avatar
2 votes
1 answer
122 views

Why does Phase-locking value show spurious effects at the beginning & end of a signal?

I am trying to understand the behaviour of the phase-locking-value, as e.g. defined here, by some simple examples. Basically, I am creating two signals with the same frequency & amplitude, where ...
a_student's user avatar
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5 votes
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How can I experimentally find the bandwidth of my PLL?

I recently designed a phase-locked loop. I would like to quantify its bandwidth so that I can better understand it. However, I made this bandwidth in an informal manner due to my lack of formal ...
ExactPlace441's user avatar
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2 answers
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Beyond "mid-side": decompose an audio stereo recording (coincident microphones) into Mid + 45° + 90°

Context: I have done in the past stereo recordings in XY position (coincident microphones): from a source far from at least 20 meters (example: piano in a big reverberant building). Since the ...
g6kxjv1ozn's user avatar
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Fringe movement analysis to extract displacement

I am using a Michelson interferometer with the interferogram recorded on a CMOS sensor. I have taken a video of the fringes moving when a displacement of 50 $\mu m$ is imposed to one of the mirrors. ...
Gianluca's user avatar
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2 answers
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CORDIC, What is it?

I am reading about CORDIC (Coordinate Rotation Digital Computer) and I have t implement it. Honestly, I am reading and don't understand the difference between phase detection algorithm ( PLL, Costas ...
AD23's user avatar
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Pointers for digital FM synthesis

I am working on a digital synthesis project, in python and c currently. I have made a Sine and Saw wave generator and have now been working on FM between the two wave types. I have successfully made ...
fredyeah's user avatar
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Can an unwrapped phase lag diagram have values beyond $-\pi$ to $\pi$?

I have a PLL that tracks the phase lag of a resonance system. When unwrapped, my system's phase lag has values beyond $-\pi$ to $\pi$. After unwrapping phase lag, are there any bounds on the phase ...
ExactPlace441's user avatar
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1 answer
158 views

Strange results with all pass compensation

I am new to DSP and, as a learning exercise, I am trying to design an all-pass filter in order to compensate the phase of an input impulse response (heqm.mat, which you can download from here). The ...
Spark123's user avatar
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1 answer
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What is the relationship between group delay and propagation delay for a filter? [duplicate]

I was trying to design a filter for a system and I was able to obtain the group delay plot in matlab using grpdelay. The group delay output is in samples. However, I was not able to relate that data ...
arun_kol's user avatar
2 votes
1 answer
332 views

Phase rotation without Fourier Transform

Is there any known math equation or other method to perform phase rotation on signal without decomposing it to frequency domain? In frequency domain it is obvious. You just need to perform phase shift ...
pajczur's user avatar
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Order one FIR Filter with complex coefficient

I am trying to learn about the behavior of the FIR filter however with complex coefficients. The filter I am trying to analyze is the following: $$H(z)=a+jbz^{-1}\quad\text{where the variable}\quad j =...
chaosmind's user avatar
1 vote
1 answer
292 views

All-pass phase compensation only in a specific frequency range

I am trying to design an all-pass filter in order to compensate the phase distortion at the output of an equalizer. To do so, I take the phase vector of the output, compute the real and imaginary part ...
skateskate's user avatar
3 votes
1 answer
175 views

Why is my resonance phase lag discontinous?

I am programming a phase-locked loop to track the resonance of a tuning fork so that the tuning fork is always on resonance. This will be used in condensed matter physics through atomic force ...
ExactPlace441's user avatar
3 votes
2 answers
762 views

minimum-phase phase via Hilbert transform returned values

Following my previous question: HRIR Minimum phase I managed to compute the minimum-phase phase of a FIR filter (in my particular case, HRTF filters). However I am not sure of the phase values ...
Mattia Surricchio's user avatar
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1 answer
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Finding the maximum phase and the maximum frequency deviation of an angle-modulated signal

I have an angle-modulated signal: $$ s(t)=10\left[\cos\left(10^8\pi · t + 5\sin\left(2\pi\cdot10^3·t\right)\right)\right] $$ How would I go about finding the maximum phase and the maximum frequency ...
B. T.'s user avatar
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1 vote
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Spectral properties of QPSK modulation

From what I've read, the spectral properties of the modulation largely depend on the rate of change of the signal phase - "a signal in which the phase changes stepwise has a broad spectrum, well ...
MagicMan's user avatar
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Why do we not encode frequency in 3 dimensions in MRI?

If I understand correctly, to select a particular slice (of an object, during an MRI scan) that is orthogonal to the direction of the main magnetic field applied, we apply a magnetic field that varies ...
Adriaan Berger's user avatar

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