Questions tagged [phase]

The tag has no usage guidance.

Filter by
Sorted by
Tagged with
0
votes
0answers
21 views

Calculating PLV on frequency-domain?

I need to calculate Phase Locking Value of an EEG signal. My data is in frequency domain, it was transformed with Short-time Fourier transform. The formula for PLV is: I see it is a function of time ...
1
vote
0answers
30 views

How to use a boxcar averager in conjunction with lock-in amplifier

Suppose there exists a temporal voltage signal composed of short pulses, modulated by a sinusoidal envelope. One desires a hardware-based signal processing scheme to maximize signal to noise ratio (...
2
votes
1answer
73 views

BPSK consecutive same symbols

I have a question regarding BPSK. If we want to modulate the bit stream $[0, 0]$ with $T_\text{ bit}=0.25 \text{ sec}$ and the carrier frequency of the cosine that carries the BPSK signal is $2\ \rm ...
0
votes
0answers
29 views

How does phase spectrum compensation works?

I'm trying to find some information that explains how phase spectrum compensation of non-stationary signals methods works, but I can't find an exact description of the procedure. I can't understand ...
0
votes
1answer
30 views

Phase difference of two time series

Consider we have two time series and for each of them , we know the phase (Phase1 and Phase2). We want to compute phase difference between these two time series. We define the phase difference as (...
0
votes
0answers
21 views

Recovering phase of harmonics in an arbitrary pulse train

I want to recover the phase of the harmonic components of a pulse train. There's a lot of cool resources out there that talk about recovering power spectra from signals in several ideal and non-ideal ...
0
votes
1answer
57 views

How to plot the phase response of Hilbert transform

The time domain signal of Hilbert transform is: $$ h(t)=1/(\pi t) $$ Its frequency response is: $$ H(j\omega)=-j~\text{sign}(\omega) $$ So if I plot the phase according to the equation I obtain: ...
1
vote
0answers
25 views

How to quantify a deterministic system?

So let me layout my question and the thought process on solving it. Say, we have some system, and we want to see how deterministic the system is. By that I mean, I mean if I put some signal (real ...
2
votes
1answer
78 views

Combination of type I FIR linear-phase systems

Let $h_1[n]$ and $h_2[n]$ be impulse responses of type I FIR linear-phase systems with lengths $M$ and $N$. What can be said about the phase response of the following filters? $h_3[n] = h_1[n] + h_2[...
0
votes
0answers
23 views

Computing Phase Difference Between Two Channels from SDR

I'm trying to compute the phase difference between two channels of a software-defined radio. I'm providing code for two different methods that I'm trying below. In both cases, I'm transmitting a pure ...
0
votes
1answer
63 views

Phasor diagram of Phase modulated signal

While studying the phasor diagrams of Amplitude modulation and Frequency modulation, I am stuck at a problem involving the phasor diagram of an angle modulated signal whose equation is given by $$s(t) ...
0
votes
1answer
73 views

Phase plot from impulse response function does not match that of the frequency response function

I have a first order linear filter $$ H(s) = \frac{1}{1+\tau\,s} $$ With the impulse response function, found using the inverse Laplace transform as $$ h(t) = \frac{1}{\tau}\,\exp\left({-\frac{t}{\tau}...
0
votes
4answers
109 views

Why do FIR linear interpolators have linear phase?

I wonder why linear interpolation is a linear-phase FIR filter. In fact, I am reading Dr. Rice's great book "Digital Communications; A Discrete-Time Approach," and he mentioned on page 466 ...
0
votes
0answers
18 views

Imaginary part of dispersion relation

Let's suppose that I have defined Real dispersion relation (f, Rek) and a imaginary dispersion relation (f, Imk). Reading simply wikipedia the group velocity takes into account only the Real part: &...
0
votes
1answer
35 views

Recovering phases of a sum of sinusoids using a DFT

I generate data in the following way: \begin{align} x_n = \cos\left(\left(\frac{2\pi}{100}\cdot 1\right)n + 0.8\right) + \cos\left(\left(\frac{2\pi}{100}\cdot 2\right)n + 0.6\right) + \cos\left(\left(\...
0
votes
1answer
44 views

converting complex sum of exponential signal to real signal

I have the following Signal model, that generates a discrete-time complex signal, where $a_k$ - amplitudes, $\phi_k$ - phases, $\alpha_k$ - damping factors and $f_k$ - frequencies are the parameters ...
0
votes
1answer
32 views

Identifying a signal by its power spectrum

Background: There is a method in optics for determining the electric field of light (both intensity and phase) via a three step process: Add a known phase shift to the light (called the "...
0
votes
0answers
32 views

group velocity and phase velocity

I am studying group velocity and phase velocity. I would like to have a confirmation if I understood correctly. If the dispersion curve is linear , do the group velocity and the phase velocity ...
2
votes
1answer
99 views

Why does my PLL simulation oscillate after locking?

I'm working on a crude circuit simulator with the goal of implementing PAL encoding and decoding, so that I can experiment with generating images that look like video transmissions. In the simulation ...
0
votes
1answer
85 views

Phase Noise and Multi-carrier Frequency conversion

I have a oscillator with a phase noise mask that was represented in dBc at specific offsets from a carrier. Two options for a multicarrier signal going into a converter, apply the phase noise mask (...
0
votes
1answer
65 views

why is my phase spectrum calculated by hand not agreeing with matlab's `freqz`?

I am trying to replicate the Matlab function freqz. To calculate the phase of the frequency response of my filter I am implementing the equation for phase: $$ \phi(...
1
vote
1answer
370 views

scipy cross-correlation: interpretation

I want to compute the phase shift between two 1-D signals of same frequency, but before I'm trying to compute the time shift between. The cross-correlation function seems to be ideal for that but I'm ...
0
votes
0answers
57 views

How to reduce phase noise in radar?

Instability of oscillator can introduce phase noise to the signal received by radar [1]. Are there commonly used digital signal processing methods can reduce the phase noise? [1] Aubry, Augusto, et al....
0
votes
1answer
44 views

Varying shift between microphone data

I had given a sine wave of frequency 2kHz as input to two microphones placed near to each other. The data grabbed by two microphones are then plotted in MATLAB and it was found out that the initial ...
0
votes
0answers
70 views

How to get the phase of a 2D sine wave?

I am trying to find the phase of a generic 2D sine wave with the 2D FFT. The formula for the phase is arctan(im/re). So I made 22 sine waves with phases ranging from 0 to 2 pi (by cropping the ...
1
vote
2answers
101 views

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,...
0
votes
1answer
73 views

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 ...
0
votes
0answers
17 views

Best choice to digitally rotate reference for an IQ filter?

I have analog GHz signal modulated with 60KHz signal and I analog mix it with reference GHz and low pass filter so now I have a 60KHz signal $a$ which I enthusiastically sample (at 1MHz). Meanwhile I ...
4
votes
1answer
60 views

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: ...
1
vote
1answer
38 views

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 $\...
1
vote
0answers
24 views

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 ...
0
votes
1answer
91 views

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 ...
0
votes
1answer
64 views

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 ...
0
votes
2answers
134 views

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 ...
0
votes
2answers
44 views

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 ...
4
votes
2answers
89 views

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 ...
1
vote
1answer
64 views

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 ...
0
votes
0answers
26 views

How to implement this phase rotator?

question 1, I think that we can use si,sq ,siq to control the phase move.In my understanding,in the Fig. 5. Phase rotator ,si, sq correspond to the values on the horizontal and vertical lines.siq ...
0
votes
2answers
78 views

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 ...
0
votes
1answer
81 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
38 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
44 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
29 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
128 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
58 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
96 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
143 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
73 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
218 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
2 3 4 5
11