Questions tagged [phase]

The tag has no usage guidance.

Filter by
Sorted by
Tagged with
0
votes
1answer
21 views

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?
0
votes
1answer
29 views

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 ...
1
vote
1answer
36 views

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 ...
1
vote
1answer
25 views

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 ...
1
vote
1answer
57 views

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)=...
0
votes
1answer
23 views

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. ...
1
vote
0answers
54 views

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....
1
vote
1answer
63 views

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. ...
1
vote
2answers
71 views

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 ...
0
votes
1answer
39 views

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 . ...
1
vote
1answer
32 views

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 ...
1
vote
1answer
24 views

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 ...
1
vote
1answer
40 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 ...
1
vote
1answer
28 views

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 ...
4
votes
2answers
155 views

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) + \...
2
votes
2answers
598 views

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 ...
1
vote
1answer
46 views

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 ...
1
vote
1answer
36 views

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 ...
0
votes
0answers
39 views

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 ...
2
votes
1answer
66 views

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'...
1
vote
1answer
112 views

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 ...
2
votes
1answer
56 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 ...
5
votes
2answers
110 views

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 ...
2
votes
1answer
40 views

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 ...
0
votes
0answers
27 views

Reconstruct phase while preserving magnitude

I was wondering if anyone could help me with this problem, I'm fairly new to audio signal processing so please bear with me. My ultimate goal is to, given a magnitude, reconstruct an audio clip from ...
0
votes
2answers
84 views

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. ...
0
votes
1answer
29 views

Compression of Multivariate Phase Signals

I have a data matrix $X$ whose columns are composed of instantaneous phases of recordings from different electrodes. In other words, each column keeps a periodic sawtooth signal with a range from $[-\...
0
votes
2answers
155 views

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 ...
0
votes
1answer
27 views

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 ...
0
votes
0answers
26 views

Instantaneous Phase Synchrony with Multiple Signals

I've recently been looking at phase synchrony to measure the Phase Synchronization between signals (following tutorial at jinhyuncheong signal processing tutorial). I.e. for two signals, retrieve the ...
1
vote
0answers
34 views

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 ...
0
votes
2answers
58 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 ...
2
votes
1answer
108 views

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 ...
1
vote
1answer
83 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 ...
0
votes
0answers
85 views

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 =...
1
vote
1answer
119 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 ...
3
votes
1answer
80 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 ...
1
vote
1answer
87 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 ...
0
votes
1answer
89 views

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 ...
1
vote
1answer
33 views

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 ...
1
vote
0answers
28 views

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 ...
0
votes
0answers
33 views

Artifacts reduction during filter cutoff change: is it possible?

I am designing a digital sound synthesizer and prototyping it using Max. The synth in question includes a dedicated filtering module, including a bi-quadratic filter whose cutoff frequency is ...
0
votes
0answers
44 views

Why the transfer function is equal to the output in this case

In this description of transfer functions on the z-plane (image linked), I'm confused by equation 1.49, which says that $H(f)=v_{out}(f)$ when $v_{in}(f)= 1 * e^{j 2 \pi (f/f_s)}$. (For another matter ...
2
votes
0answers
57 views

Stability of filters with negative phase delay, group delay, and positive phase

Lets assume I have an IIR filter with : bz = [1.0195 0 0]; az = [1 0.0166 0.0020]; fvtool(bz,az) The filter is stable as i can see. If you check the phase delay ...
0
votes
1answer
39 views

Filter design for an unusual EEG experiment

I'm designing a quite unusual (in terms of signal analysis) EEG experiment, which forces me to design my own filter. I have never done this before, so kindly please check my work and suggest ...
0
votes
0answers
20 views

Interpreting FFT Phase - why phase of a cosine?

I understand how to interpret the magnitude result from the FFT, but why is the phase that we obtain, arctan(Im(x)/Re(x)) indicative of the phase shift of a cosine graph, and not a sine graph?
0
votes
1answer
54 views

Convert measured spectrum to impulse response

I am still learning, so please bear with me: My audio measurement tool exports the measured spectrum of the DUT in the following format: Frequency [Hz] Magnitude [dB] Phase [degree] It is stored in ...
2
votes
2answers
125 views

Non-zero DFT components where zero is expected?

I am implementing DFT in Octave. Here's my code: ...
0
votes
0answers
30 views

Getting the “phase” in a streaming way?

The context is a supervised learning problem. I have a dataset with features X and a target y. Among that dataset there is the date of the day encoded as an integer starting at 1. I have around 10k ...
0
votes
0answers
17 views

How to get the phase/angle from an Alglib complex variable

It is easy to get the magnitude using alglib.abscomplex function (https://radfiz.org.ua/files/temp/Lab1_16/alglib-3.4.0.csharp/csharp/manual.csharp.html#gs_stdfunctions), but I would like to know, how ...

1
2 3 4 5
11