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Questions tagged [delay]

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5answers
3k views

Is a notch filter for 50 Hz without delay possible?

I am processing an EEG signal (2 kHz sampling frequency) from hardware and the built-in filter doesn't work as intended. FIR gives a delay, and IIR is unstable. The signal of interest is from 4&...
0
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2answers
36 views

What is effect of fractional sample delay effect on FIR Filters?

In the DSP lecture slides we have this slide: And So why this part of FIR Type 2 and Type 4 filter impulse response equation bolded in this slide? Thanks for your attention.
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2answers
37 views

How is time or sampling rate accounted for in this model?

A basic model of coupled strings (eg. piano) is provided here as: The principle is that it has two identical string simulations each formed by a delay line and LPF. The outputs of these are summed at ...
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0answers
23 views

Problem in finding the delay between two signlas

I'm using find delay block to estimate the delay between two signals. Here is my configuration parameters : The error that i'm facing :
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0answers
23 views

GCC-PHAT for Multiple Sound Sources

Can GCC-PHAT be used to detect multiple time-delays (that is, having multiple acoustic sources simultaneously)? The documentation for the gccphat(sig,refsig) ...
0
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0answers
54 views

Calculating output of a digital system signal with a filter that introduces delay

We have a step function at the entrance that goes through the following system. The $D(z)$ digital filter introduces a 0.25s delay. Output as $y(kT)$ must be calculated. How can we tackle this problem?...
0
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0answers
23 views

Z transmittance from diffrence equation made out of diagram

I have a problem with getting Z transmittance out of a single block of diagram, when e(nT) is as an input, and u(nT) is as an output. Period of sampling is T = 0.5 s The diagram is: My first thought ...
1
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1answer
74 views

Compensate delay of non-symmetric (non-linear phase) filter

Lets assume I want to apply a matched filter h which is non-symmetric to my signal x and the output is ...
0
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1answer
48 views

What factors affect the propagation delay at wireless communication?

Generally, the signal propagation delay is d/c. d is a distance between a transmitting antenna and a receiving antenna. c is light speed. However in NS-3, there is Random Propagation Delay Model ...
3
votes
1answer
203 views

Maximum cross-correlation coefficient value for time delay estimation

I am using cross-correlation for time delay estimation of two synchronized recordings ($x_1$ and $x_2$) of a fixed sound source from two different locations. I understand that the delay is associated ...
1
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1answer
34 views

Plotting phase delay from first principles giving different result from phasedelay() function. Why?

I have a length 10 Finite Impulse response as shown below, and I am trying to find the phase delay of this FIR. $$h[n]=\begin{cases}0.1,& 0\le n \lt 10\\ 0,&\textrm{otherwise}\end{cases}$$ I ...
0
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0answers
30 views

Mathematical expression for a system

I have a system that delays the input with k samples and concatenates the new input with delayed one so that y = [x(n) x(n-k)] so if the input comes with n samples the output should be k+n samples. ...
1
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0answers
143 views

Implementing real-time variable fractional delay line in Matlab

I am attempting to implement a fractional delay line in Matlab which operates in real time, uses an object-oriented approach, and whose length can be modulated each time a sample is processed. I have ...
0
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2answers
161 views

Delay in Savitzky-Golay filtering

I am applying a Savitzky-Golay filter to a signal, using the scipy function. I need to calculate the lag of the filtered signal, and how much is it behind the original signal. Could someone shed ...
1
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0answers
57 views

Time delay estimation of signals increasingly decorrelated

The problem may be summarized as follows: I have a stochastic signals and I want to measure an increasing delay, as depicted in the following picture. The picture represents the signal as it is being ...
0
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1answer
614 views

GCC-PHAT (Generalized cross correlation) always peak at delay=0 on real audio signal

I have studied the GCC-PHAT algorithm to estimate TDOA on audio signals at 2 mics. Here is my MATLAB implementation: ...
0
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1answer
232 views

What is the meaning of inverse signal bandwidth?

I have been studying the two ray model in communication systems. The text I'm studying has two signals, $u(t)$, which is Line of Sight and $u(t-t')$, which is the reflected signal. It quotes, ...
0
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1answer
243 views

90 Degree Phase Shift / Rotation Algorithm for SDR

I'm working on a library to preform frequency demodulation from an SDR signal. I'm using https://github.com/sysrun/rtl-sdr/blob/master/src/rtl_fm.c as a crib for this. The algorithm starts by taking ...
3
votes
1answer
69 views

Is it possible to design a band-pass filter with fewer taps than a series HPF + LPF?

I am digitally filtering a signal that is streaming live. The goal is to reduce the filter delay as much as possible while maintaining the quality of some measurements based on the filtered signal. ...
0
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1answer
63 views

How to correct a QAM time delay

How can you correct the anticlockwise rotation that occurs in the received constellation of a QAM system? My only idea is to compensate the delay with an advance but this is impossible since you ...
0
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1answer
38 views

What is the z-domain transfer function of variable delay?

Is it possible to obtain the transfer function of a signal that has a variable delay? For instance, I have a signal consisting of 10 samples: 0,1,1,1,1,0,0,0,0,1 If I would apply a unit delay to ...
1
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1answer
204 views

FIR filter to delay signal [duplicate]

About filter design, mostly we want to control frequency amplitude response and the linearity of phase response. I wonder whether there are FIR filters specialized to delay signal? For instance, let'...
0
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1answer
97 views

Findin the source direction using cross-correlation function

I am new to DSP and I'm working on the following problem. We have a sound source in the far field and a microphone array consisting of two microphones with distance d. We want to determine the source ...
0
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1answer
113 views

difference equation block diagram delay or advance confusion

When does the unit delay, become unit advance essentially. Goal is to deduce difference equation from block diagram. Green text is notes about what the value should be in that node of the diagram. ...
2
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1answer
505 views

Implementation of a Variable Fractional Delay with Lagrange Interpolation using Farrow Structure

I am writing a C++ simulation software working in time domain. I generate regularly sampled data, and need them to be delayed, in "real-time", by a variable fractional delay. This is a pretty common ...
0
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2answers
3k views

What exactly is a 90 degree phase shift of a digital signal in FM demodulation appraoches?

I am working on an FSK demodulator (1200/2200Hz, 1200 baud) featuring a 90 degree phase shift operation. I don't exactly understand what 360 degrees mean for a digital signal. My sampling frequency ...
1
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1answer
351 views

digital IIR filter delay and oversampling

Can oversampling decrease the delay of digital IIR filter? Imagine there is some digital signal going into processor that applies low pass filter.Lets say its 1 KHz sample rate and the filter is ...
0
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1answer
37 views

Dynamics processor for speech - apply gain on delayed samples?

A Dynamics processor (limiter, compressor, expander, and gate) is calculating the output gain at some point in time, and it is applying this gain at some delayed point in time. This allows for ...
0
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1answer
205 views

Emulating a Variable Delay

I am trying to emulate a satellite link where the delay time between the satellite and ground station changes over time due to the satellite's motion. I plan do this by converting to the frequency ...
0
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3answers
312 views

Fractional Delay using Polyphase Filter

How to use rectangular window design to design a length-9 polyphase filter which delays an input signal by 3/5 of a sample? An expression for the 9 coefficients is required.
0
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1answer
659 views

Converting Time Shift to Phase Shift

I have just started taking signal & systems lessons and here is my question: If we say that x0(t) = A.cos(w0t). (a cosine signal with zero phase shift, w0 ...
0
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0answers
120 views

Bandpass Fractional Delay Filter

I am designing a fractional delay filter, I found this code for lagrange FIR fractional delay filter, The fractional delay filter acts as a low pass filter, it passes low frequencies from 0 to 0.25*fs....
1
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1answer
454 views

How to calculate the delay generated by a 2nd order all-pass filter

I'm trying to simulate the dispersion effect of a stiff string in a digital waveguide system, by using second-order all-pass filters. I use a second order all-pass filter with this transfer function:...
2
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0answers
161 views

How can I oversample the received signal by double of sampling time and have two signals

I have a question, how can I make the sampling in Matlab for the received the signal by half of time duration of symbol (Ts), and have two copies of signal (that's the process of fractional sampling ...
1
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0answers
284 views

Time-Delay beamforming delay computation

I'm trying to implement a beamforming algorithm in python and I'm stuck with the time-delay computation for a rectangular array. I'm using the following equation to compute the delays based on the ...
0
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1answer
178 views

Audio transfer function modelling with pink noise + signal

I'm trying to model a transfer function for a noisy audio system, specifically to measure delayed system response. Before I can confidently apply control, I need to verify that I can exert control ...
0
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2answers
84 views

Calculation of autocorrelation - does calculation “loop”?

With a delay $l$, autocorrelation is defined as: $$r_{xx}(l) = \sum_{n=-\infty}^{\infty}x(n)x(n-l) = \sum_{n=-\infty}^{\infty}x(n)x(n+l).$$ I want to calculate the autocorrelation of a signal $$x(n)...
2
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1answer
512 views

How to calculate a delay between two signals in frequency domain?

Calculation of a delay between two signals is generally done by finding the maximum in the cross-correlation of the two signals (in time domain): $$ \tau_{delay} = \arg\max_\limits{t}(f(t) \star g(t)) ...
1
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0answers
112 views

Sensor fusion under unknown correlations: can covariance intersection account for delays?

Of late, there has been some interest in cooperative estimation algorithms in robotics, where the information sources are usually sensors such as cameras. When multiple robots observe surrounding ...
0
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2answers
78 views

audio signal time delay estimation(TDE) in indiviual and separate mics

common TDE problems algorithms(such as GCC) often require audio signals in different mics concurrently, however, is it possible to estimate audio signal time of arrivals(ToA) in different mics ...
3
votes
0answers
72 views

Minimum time delay that can be estimated between two sensors

Consider a 1-dimensional toy problem. I have two sensors at different points along the $x$-axis. Somewhere away from the sensors, a disturbance is created which travels towards the sensors, first ...
2
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1answer
204 views

Can a unit delay in discrete time be represented by exponential functions?

If we have a signal $y[n]$ and its unit delayed version $y[n-1]$, can we write $y[n-1]$ in terms of $y[n]$ times some exponential? The reason I want to do this is to then take $y[n]$ common and ...
1
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1answer
76 views

How to quantify delay in filtered output?

I have a signal containing two sine tones 30 kHz and 60 KHz. I used a second order IIR notch filter to filter out the 60 KHz component from the signal, so now the signal has only 30 KHz component. ...
1
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1answer
204 views

Finding audio signal time delay: cross-correlation vs. impulse response?

I need to find a time delay between the two audio signals, one comming from one set of speakers, and the other being the source signal that is initialy sent to speakers. I send some noise through ...
1
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1answer
1k views

LTI system $y(t)=x(t-T)$ with or without memory

How can I verify if the LTI system ($T$ is a real number, $y(t)$ output, $x(t)$ input): $$y(t)=x(t-T)$$ is with or without memory? I know that, if $y(t)$ depends only on $x(t)$, the LTI system will ...
1
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0answers
91 views

Why prediction by AR model causes time lag

Why does prediction by AR model cause a time lag? Please tell me why theoretically.
0
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1answer
311 views

Compute Power Delay Profile (PDP) from Delay Spread

I have data pertaining to channel obtained from measurements. In order to make use of this data, I need to convert it into a form as follows: ...
0
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1answer
270 views

Time variance of $y(t)=x(2t)$

At first I had trouble proving the time variance for this as I would do the usual mistake as in question Is the system represented by the equation $y(t) = x(2t)$ time invariant?. The solution has ...
1
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0answers
112 views

How to find and fix the delay of a modulation

I am creating a model in MATLAB to simulate power line communication, but I found a problem. I'm very new to the DSP area, I get my code below from a MATLAB example. ...
0
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1answer
225 views

Successive dynamic time warping with a set of window sizes

I am applying DTW to a set of data. I haven't figured out a solution yet, still searching for ideas, and I'm currently trying to apply DTW successively with a monotonic set of windows. Let's say i ...