Questions tagged [phase]
A quantity representing the fraction of cycle of a periodic signal, usually represented as an angle.
623
questions
0
votes
0
answers
16
views
how to log phase of NWC Australia 19.8KHz in a file in python
First I am very new in this field,and i am doing a college project and i stuck at determining phase of msk signal which is transmitted from a radio stations called NWC Australia 19.8Khz , so let me ...
0
votes
0
answers
28
views
Modelling phase noise for self-heterodyne method
I am trying to model the phase noise $\phi(t)$ of laser used in self-heterodyne method using python code. The noise is time-dependent. The noise follows the condition that
$$\langle(\phi(t)-\phi(t-\...
0
votes
1
answer
106
views
Phase Spectrum of Signals
I did fft of a fish's trajectory, because it looks periodic and I tried to find the frequency. However, I can't understand what does the phase spectrum below represent. Does this lower left to upper ...
0
votes
1
answer
98
views
phase unwrapping relative to a reference
I have samples of wrapped $(-\pi,\pi)$ phase from a bandlimited signal
$A(t)\cos(\pi\omega t + \phi(t)+\theta_0 )$
Frequency is constrained by very regular physics and I know a preliminary guess $\hat{...
2
votes
3
answers
253
views
Phase compensation using IIR allpass filters
As an exercise with IIR allpass filters, I am trying to compensate the phase of a lowpass Linkwitz-Riley filter using the Matlab integrated function iirgrpdelay.
The code I am using is the following:
<...
2
votes
1
answer
42
views
Filtering after a phase domain ADC
While researching receiver architectures for the demodulating constant envelope signals like a GFSK, I stumbled over the concept of phase domain ADCs, where after
$$\boxed{\text{LNA}}{\longrightarrow}\...
0
votes
0
answers
29
views
Integrating CWT around nominal frequency with amplitude and phase
I have a real signal f sampled at 96Hz composed of clusters of harmonics scattered tigthly around evenly central frequencies close to 1Hz and 2Hz (multiples of 0.966Hz) that I'll call features. These ...
1
vote
1
answer
67
views
Finding phase of a received signal using spectrogram function
I am trying to find the phase of my dataset between a range of frequencies. I can't post my code or data but generally speaking, the frequencies range from 10 to 100kHz and I need the phase between 20 ...
2
votes
2
answers
1k
views
Real world use case for a battery with phase?
Referencing the following exercise by Dan: $9\rm V$ Battery with $45^\circ$ phase, I'm curious on what this would be used for in real world applications?
0
votes
1
answer
106
views
Computing Phase detector in PLL
I have been trying to implement PLL in a STM32 microcontroller. Starting with the first step, I want to implement a phase detector. I tried to first simulate in Python so that I can later use in STM32....
0
votes
1
answer
137
views
Computing phase difference between two sinusoidal signals
Based on this post here, I tried to calculate the phase difference between sine waves. Here is my code.
...
0
votes
1
answer
126
views
Correlated phase noise
I am trying to find a mathematical model to understand the correlated phase noise.
Here, I see the reference phase noise is almost the same after up-conversion and then down-conversion. How does ...
0
votes
4
answers
149
views
FIR filters: is it possible to manipulate phase without change in magnitude response
Here's response of FIR design:
which shows SPL 0dB and here's a wave file exported from ( DRC ) FIR design software: FIR48kHz.wav.
Audio software (internally uses FFTW routines) where this filter is ...
1
vote
2
answers
91
views
Scenarios where Phase Response is (non-)problematic
In order to get a better feel for phase response and how it applies across the field of dsp, I'm looking for example scenarios where a filter's phase response is a concern and where it is not.
Take ...
1
vote
0
answers
25
views
How to calculate phase estimation error
I am working on speech enhancement and I want to compare the phase and magnitude between two signals. I compute the STFT for both, and comparing the magnitudes is easy via mean-squared error or some ...
-1
votes
1
answer
40
views
Phase of signal can affect the data rate?
Does the change of phase of the signal affect the data rate?
Actually, I consider the RIS(Reconfigurable Intelligent Surfaces) between the transceiver and receiver. I wonder if adjusting the phase ...
1
vote
0
answers
28
views
What could be the cause of oscillating differential phase between a 2 channel audio signal
Test Setup
I have two i2s microphones (INMP441) on a common clock. They are designated as the left and right channels with a sampling rate of 22050Hz. The generated signals are stored as WAV files and ...
1
vote
2
answers
44
views
visualizing frequency and phase of a system's response to an impulse
Given a .wav file that is a LTI system's response to an impulse, what would you recommend as the simplest way to plot the frequency and phase output of the system? I'm already working in Python, so ...
0
votes
1
answer
52
views
MSK without I/Q data
I just started a while ago with DSP and slowly staring to understand the concept of I/Q and what it means. I successfully could decode some bfsk, bpsk and wanted to move to msk which as not easy to ...
1
vote
1
answer
70
views
How to remove Phase Offset from PSK signal?
Suppose you have captured IQ data from a PSK modulated signal with intermittent blanks between signal transmission as shown in the figure below.
I want to be able to automate and run an algorithm on ...
1
vote
0
answers
24
views
Depth estimation using phase shifted sine waves
For 3 phase shifted sine waves using the projected pattern: I = sin(x + δi) where δ ∈ [-2pi/3, 0, +2pi/3] which is then projected onto a scene. The resulting image is captured with a camera. I am ...
0
votes
1
answer
33
views
Why is phase lost in x-ray crystallography?
everywhere says that phase is los but WHY?
it is that when we measure x rays we cannot measure phase?
is it that phase is lost because of such high scattering?
what is the REASON for the phase lose in ...
1
vote
1
answer
56
views
Deducing phase from frequency response $1-z^{-1} $
In Boaz Porat's book about signal proccessing, at part 8 he mentions the example:
$$ H\left(z\right)=1-z^{-1}\Rightarrow H^{f}\left(\theta\right)=1-e^{-j\theta}=\left(e^{\frac{j\theta}{2}}-e^{-\frac{j\...
4
votes
1
answer
252
views
Phase Difference Calculation in Frequency Domain
I am currently working on an application in which I have a Linear acoustic array, the audio of which is analyzed using FFT. Now I also want to perform phase difference calculation and have also learnt ...
0
votes
1
answer
18
views
Demonstrating zero phase of vertically symmetrical signals
I'd like to get a zero phase for vertically symmetrical signal (as it done here, FIGURE 10-7).
For this purpose, I tried to test it on gaussian signal in Python:
...
1
vote
1
answer
51
views
Is there a ''standard'' or commonly accepted reference for the phase of the most usual signals?
I am working with some very common, simple signals, such as square, triangle and sawtooth.
In my case the phase of such signals is important, so I want to be consistent throughout my work. For example,...
1
vote
0
answers
76
views
How to get correct phase values of the signal using Recursive Discrete Fourier Transform
Question
I'm trying to understand the relation of the result of the recursive DFT to the original signal. I have a signal with a sampling frequency of 4000 Hz and the recursive phasor estimation ...
0
votes
0
answers
46
views
Doppler radar: phase shift sign convention
In my reading about Doppler radar principles, both of the sources I've been using have made a peculiar choice of sign convention: the phase shift of the received pulse relative to the transmitted ...
0
votes
0
answers
44
views
Phase vocoder has crackling artifact
I built a phase vocoder in JavaScript based on this paper. It works great, except for a crackling artifact that is present in the rebuilt signal.
I recorded this clip if you want to hear what it ...
6
votes
2
answers
86
views
Best parameter to estimate image reconstruction quality?
Context: I am a PhD student in physics and right now I am studying phase retrieval with low illumination
With two different parameters I obtain these two images:
With hight illumination (less noise) ...
2
votes
0
answers
59
views
How to sum amplitudes only without distorting the signal?
I do audio signal processing using Python (scipy, numpy etc.) I'm trying to "mix" 2 audio signals in a way that reduces phase canceling as much as possible. So I do an FFT of the 2 signals, ...
1
vote
0
answers
43
views
Deriving the IF phase equation of FMCW
My understanding of the FMCW was limited to one chirp and was mostly focused on frequency analysis. (Mostly built upon this answer)
I wanted to expand my understanding to multiple chirps and was ...
1
vote
1
answer
141
views
Sampling Time Offset estimation for OFDM signal
I have a signal constituted by known OFDM symbols, and my goal is precisely estimate the Sampling Time Offset (STO). However, while the STO in the context of a single-carrier modulation is pretty ...
1
vote
0
answers
67
views
numerical time differentiation in GNURadio
I'm hoping to put together a cheap modulation monitor for wideband FM radio using an rtl sdr usb, on the FCC website, it's listed that the modulation percentage for an FM station is the actual ...
0
votes
2
answers
125
views
Why does an FFT-based filter change phase?
I am very new to DSP, and I'm just trying to figure stuff out here. I saw a video which stated that a filter implemented using an FFT would alter the phase of different frequencies differently. The ...
0
votes
1
answer
114
views
Finding the maximum frequency deviation and phase deviation
I'm trying to solve a problem regarding communication and I'm stuck. The questions asked me to find the maximum frequency deviation are usually written in cos or sin wave. But this question isn't, so ...
1
vote
0
answers
68
views
Adding $n\pi$ to the phase when estimating the phase velocity of a sound wave through a material
Setup
I'm estimating the phase velocity in a wooden table by using an actuator and 3 sensors. The actuator sends out a chirp and on the table there are 3 accelerometers with distance $d$ between them. ...
0
votes
0
answers
45
views
Spectral leakage with phase error? Complex convolution?
As we know, phase is very important for a signal.But I don't know much about the cause of phase errors.
Spectral leakage is equivalent to convolution of the spectrum of the original signal and the ...
0
votes
1
answer
62
views
Reason for "buzzing" artifact over processed audio after IFFT
I made a program that can change pitch of a recorded audio clip while maintaining its duration. Basically, it takes the FFT of windowed segments of a recorded signal, processes them using phases to ...
1
vote
1
answer
136
views
Behavior at DC and Nyquist of an ideal phase shifter
In Matt L's answer he states that an ideal phase shifter with a phase shift $\theta$ has a frequency response
$$
H(\omega)=
\begin{cases}
e^{-j\theta},&\omega>0 \\
e^{j\theta},&\omega<0
\...
2
votes
0
answers
82
views
Synchronization of two noisy sinusoidals signals
I have two noisy sinusoidal signals and I am currently investigating solutions to synchronize them using python. Here is an example I made to illustrate my goal, supposing that I generate these two ...
0
votes
1
answer
64
views
IIR Allpass Filter Phase Response Plotting in Excel
Using formula on Audio EQ Cookbook I implemented biquad IIR filters in Excel.
As in my previous question Phase Response Function / Plotting in Excel (IIR Filter), Hilmar helped a lot with the phase ...
0
votes
1
answer
343
views
Phase Response Function / Plotting in Excel (IIR Filter)
Using formula from Audio EQ Cookbook I implemented biquad IIR filters in Excel.
I can now plot every transfer function and total of 8 band EQ with shelvings and peakings.
My problem is, I can not ...
1
vote
1
answer
1k
views
How to correctly get the amplitude and phase of the signal after applying the fast fourier transform to it
I am new at signal processing and was trying to understand the relation of the result of the FFT to the original signal.
I generated a signal with a sampling rate of 100 Hz within 1 second ($N=100$), ...
2
votes
1
answer
169
views
Wrapped phase and phase unwrapping in vital sign detection
I am quite new to the world of radar signal processing and there is this issue that I can't figure out for the life of me.
In Remote Monitoring of Human Vital Signs Using mm-Wave FMCW Radar (Section ...
0
votes
0
answers
174
views
Phase Unwrapping Issue of IQ data sample in Radar Signal Processing
I am doing radar sensor signal processing.
The radar sensor gives iq data corresponding to the range (sweeps).
I want to detect micro motion so that phase analysis is used.
Sweep is the distance ...
0
votes
0
answers
33
views
$S/N_0$ of a PM Modulated tone
I have been looking into a Satellite tone ranging system.
Phase error Performance criteria has been given as a function of $S/N_0=40 dB.Hz$ of the Major tone.
The major tone is 100 kHz away from the ...
1
vote
1
answer
99
views
Why do I get a phase of the FFT of a cosine function when the phase is zero?
I'm trying to find the phase of a cosine function with the FFT but I don't understand the results from the plots. I did two separate examples for two phases $\phi$: $\phi_1 = 0$ and $\phi_2 = \pi/3$. ...
1
vote
1
answer
67
views
Is the magnitude of the phase shift independent of the volume of the sound?
Sound waves can cause vibration of the particles/objects that are scattering/reflecting/emitting the light. Since vibration is spatial displacement, it causes a phase shift by affecting the value of &...
0
votes
1
answer
95
views
How to explain the meaning of the intersection in a Fourier series representation of periodic signals?
I saw a piece of code on github which transforms the planetary movement into the Fourier wave function.
These circles are given by the $x$ and $y$ ordinates: $x=\cos (\omega t)$, $y=\sin (\omega t)$, ...