Questions tagged [digital-filters]
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253
questions
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1answer
37 views
why there is no 0 on the right side? (matlab, low pass filter)
I took even number of sample (in this case 6) from sinc, hamming window, and multiple of those two.
then after fourier transform, frequency-domain variables have zero only left side, in this case its ...
2
votes
1answer
47 views
Applications for the Maximum Phase Filter
A maximum phase digital filter has all zeros outside the unit circle, and has the maximum phase and therefore longest delay for a given magnitude response.
Besides the possibility of needing a ...
0
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1answer
25 views
Remove a signal that is known to repeat every 4 samples at a known phase i.e. exactly 500 Hz signal in 2000 Hz data
I have a situation that the measurement device is generating a known signal in the data at 1/4 of the rate. In this case that is a 500 Hz signal when sampling at 2000 Hz.
Now, I can already measure ...
0
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0answers
24 views
Filter design with arbitrary response [duplicate]
I would like to design a feedforward filter for a current controller. I could of course run MATLAB to brute force an arbitrary response for me, but I have some ranges "don't cares" in the response ...
0
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1answer
45 views
Extract a signal that is known to repeat every 4 samples at a known phase i.e. exactly 500 Hz signal in 2000 Hz data
I have a situation that the measurement device is generating a known signal in the data at 1/4 of the rate. In this case that is a 500 Hz signal when sampling at 2000 Hz.
Now I can extract the 500 Hz ...
0
votes
1answer
25 views
How to design a filter that can filter out noise accurately, after setting the parameters of the filter using standard signal?
I meet a problem with designing a filter. I have two different instruments that could measure the same AC signal (usually ~200hz, always <1kHz), A and B. A can carry out signal measurement during ...
-1
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0answers
27 views
Matched filter (Non-Sychronous Detection)
I have IQ samples data file, RF data, that I sampled it by dongle SDR RTL which this file has packets that I transmitted them and the dongle has sampled them, so the IQ samples data file which is the ...
1
vote
1answer
43 views
Numerical differentiation on circular data
I have multiple time series of position data (x, y, z) and orientation data expressed as Euler/Tait-Bryan angles (yaw, pitch, roll) obtained from a head tracking device.
I need to obtain velocity ...
0
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2answers
28 views
IIR Cascaded Filter Response, Unexpected Results
I am attempting to understand how to manipulate portions of a cascaded series of biquad notch filters in a control system I am working with.
As part of determining the composite response of all the ...
0
votes
1answer
39 views
Calculating the cutoff frequency of a highpass digital filter
I am new to DSP and I am trying to find the cutoff frequency of a HP digital filter. I know the equation that describes the system, its frequency response: $H(e^{jĻ})= 1 - \frac{e^{jĻ}}{2} - \frac{1}{...
0
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0answers
9 views
chromatic and polarization mode dispersion compensation in electrical dmain
I am currently working on adaptive compensation of chromatic and polarization dispersions in the electric domain using LMS (least squares method) and CMA (constant module algorithm) algorithms.
I am ...
-2
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0answers
21 views
How does the length of matched filter affects the fft of my signal
I have one matched filter that Im applying it on FM signal (with noise) in order to detect specific signal from my FM signal(with noise), Im trying to find out what's the relation between the length ...
2
votes
1answer
50 views
Polynomial division to separate FIR and IIR in cascade
I have a FIR filter $L(z)$ and an IIR filter $H(z) = \frac{B(z)}{A(z)}$ which are cascaded together as $L(z)H(z) = L(z)\frac{B(z)}{A(z)}$.
For specific reasons I want to calculate a parallel topology ...
1
vote
2answers
31 views
Digital filtering based on frequency component amplitude… why not?
I've got a very general question.
I've just implemented a filter working in frequency domain that simply cuts every frequency component whose modulus amplitude falls below a certain threshold value. ...
0
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0answers
26 views
How to use background noise information to de-noise a (non-stationary) signal
I performed some measurements, which unfortunately include some noise. The measured signals are non-stationary, because the phenomena I am capturing is a transient.
Before the transient, I recorded a ...
1
vote
2answers
43 views
what does the order of filter mean?
Recently, I read a paper. In it, it said "a $32^{nd}$ order 100MHz bandpass filter". So, how the filter was designed? Does it mean this filter have 32 taps?
2
votes
2answers
92 views
Can I set a constraint on the first tap of an FIR filter such that its inverse is stable?
Let's say I have the following FIR filter $h[n]$, so the output $y[n]$ for an input $x[n]$ is
$$
y[n] = \sum_{k=0}^{m-1}x[n-k]h[k]
$$
The inverse of this filter is given by the IIR difference ...
0
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0answers
10 views
Estimating velocities from IMU Acceleration
I hope someone can help me to figure out the best way to solve my problem
I'm trying to drive a Cuboid on V-rep simulator with velocities
What I'm receiving is accelerations from an IMU (MPU9250 acc+...
1
vote
1answer
52 views
How does Overlap-Add work for IIR filter?
So let's say I'm trying to implement something like an LPC vocoder. I analyse a speech signal by breaking it up in small chunks and determining their LPC coefficients, which are by design, the ...
1
vote
1answer
38 views
How to use matlab toolbox for 2qam dfe equalizer?
I made Channel equalization with matlab,
You can find the code below.
...
0
votes
2answers
40 views
Q format doubts
Is my understanding correct w.r.t Q format.
signed Q15.1 format means, 15 bits for fractional and 1 for integer bits
SO max range is - 2^15 / 2^15 to + (2 ^ 15 - 1) / 2^15
signed Q7.0 means, 7 bits ...
0
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0answers
19 views
Remove known sound from signal
I'm currently getting FFT values from the music playing from a user's PC. However, my application also generates noise which interferes with the FFT data as my app's sound is also coming out of the ...
0
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1answer
114 views
Filter: IIR Filter
How IIR Filter coefficients formula derived? for LPF, HPF, BPF, BSF there are coefficients formula for a0, a1, a2, b0, b1.
How it came? I would like to know the derivation for all those coeffs w.r.t ...
0
votes
1answer
30 views
How can I find the transform function, amplitude and frequency response of a digital filter in python?
I have applied a laplace filter mask to an image and now I want to find the amplitude and freqency response of a laplacian filter: [[1,1,1], [1,-8,1], [1,1,1] ]. I know I need to first find the ...
1
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0answers
28 views
Help on understanding Gardner's original paper for QPSK symbol timing recovery?
I am fairly new to DSP and RF receivers in general, and I was recommended to read Gardner's original paper for symbol timing error recovery for QPSK signals.
I have a question regarding an equation ...
0
votes
1answer
29 views
What is absolute ripple specification and how does it arrive in low pass prototype for Butterworth?
Digital Signal Processing by John G. Proakis, Dimitris G. Manolakis(4th Edition) gives the prototype function for Butterworth low pass filter in an analog system which is fine till the point where the ...
0
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0answers
23 views
Do we need a transmit and a receive filter in a OFDM transceiver system? [duplicate]
can anyone specify in brief what are the filters that can be used as a transmit and receive filter in OFDM. Any material to start with will be very much appreciated. Thank you!
0
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1answer
29 views
how can the channel fading model (Rayleigh, or Rice, or Log normal distribution) infer the way channel estimation is done?
For a dense urban environment with rich scattering and no Line of sight (LoS)
path, the Rayleigh distribution can be used to model the fading.
Rician fading is a stochastic model for radio propagation ...
0
votes
2answers
59 views
What does filtering do to a signal in time domain? Does the signal gets distorted?
When considering a transceiver system, if we do a certain filtering operation on the signal, will the BER of the system be affected? My point is, since filtering in frequency domain filters a portion ...
0
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0answers
66 views
First order IIR high pass filter
The cutoff frequency is 0.05 Hz. The DC offset of the signal is 5mv. How to determine when the signal will stabilise to the baseline?
0
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0answers
43 views
Can someone explain or elaborate on the channel estimation and noise variance estimation algorithms used in HF receiver?
For different type of communication, there is different type of algorithms to acquire CSI.
For instance 4G (LTE) network have SRS or DMRS to estimate the channel based on pilots.
I am designing a ...
1
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2answers
62 views
Eye pattern construction and interpretation
I have read some text about the eye pattern (or eye diagram), but I do not understand how should I read it.
The wikipedia definition of it is this one:
In telecommunication, an eye pattern, also ...
0
votes
1answer
40 views
Help in designing filter for DUC (Digital Up-Converter) and DDC (Digital Down-Converter) using the built-in DUC and DDC blocks in MATLAB Simulink
Can anyone please help me in simulating a simple BPSK transceiver system that correctly receives a signal through a DUC and DDC? I have attached the screenshot of my Simulink system along with ...
0
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0answers
29 views
Hydrophone signal calibration by frequencies
First of all excuse me if anything I post is completely or partially wrong (or poorly explained), I am new in signal processing and still learning a lot from this community, I will do my best to ...
0
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3answers
89 views
I can't wrap my mind around the concept of filtering and the unit circle ? any help? [closed]
Can someone elaborate this theory where there is a link between the stability of a filter and the zeros or nulls being on the unit circle?
0
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0answers
25 views
How to compute the DFE based MMSE equalizer FF and FB coefficients in a non adaptative way?
I seek your assistance,
I am reading the Proakis 5th edition and I came across a paragraph explaining the tuning of DFE filters, i.e, how to compute the FF(FeedForward) and FB (Feedback Filter) ...
0
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1answer
56 views
Noise Reduction Moving Average FIR
I read that the noise reduction of a moving average FIR can be expressed as the square root of N where N is the length of the filter.
How do you prove? I can't quite get it.
1
vote
1answer
50 views
How to match zero-pole diagrams to their frequency responses (Discrete Time)
I get confused when there are a lot of zeros/poles in the zero-pole diagram and I find difficulty understanding their frequency response.
I know the following:
1. Complex conjugates cause double ...
0
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0answers
20 views
HF ionospheric Channel Model Example in matlab : Watterson model
In the example file in matlab HFIonosphericChannelModelExample.m, the watterson model is simulated. In this model the channel is represented as one tap (for the sake of simplification) delay channel.
...
0
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2answers
51 views
Filter response to sinusoidal input signal
This question is related to Does 46 dB gain of a filter for a frequency imply 200 times more amplitude? In the accepted answer it is mentioned that "For a sine wave input the amplitude of the steady ...
0
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1answer
17 views
Load cell noise filteration
I'm currently working in a project as apart of a student team.
Setup
A platform is attached (placed over and screwed) two 1 Kg load cells in order to measure the weight of the system. A vibration ...
1
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0answers
132 views
Early-Late Symbol Synchronizer on Non-Triangular Pulses
I've been studying the basics of digital communications using the free book at desktopsdr.com.
One of the examples is a 4-QAM demodulator which where symbol timing recovery is done with some Early-...
0
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2answers
39 views
How to re-program/modify sound frequencies without DSP processor?
I'm developing a mobile application that controls Bluetooth sound-speaker functions, which includes an equalizer to modify the output audio frequencies.
The audio processing module on the speaker ...
0
votes
1answer
60 views
how to stop matlab from rounding my values and keep them at same precision during calculations?
here are my IIR coefficients:
CoefIIR=[1.630078934734 1.267893338385 1.112390120011]
and here are the result given to me by matlab commands:
...
-1
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1answer
35 views
std::cosf fluctuation: Results are off in low frequencies [closed]
I attempted to generate a continuous wave signal by using the C++ cos/sin functions. It's partly successful, meaning high frequencies seems ok, but very low frequencies give unexpected results. The ...
0
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1answer
47 views
Modeling audio effects, reverse engineering
Okay so I'm relatively new to signal processing and don't know the specific terminology to help narrow my search, but I'm looking for advice in the form of books, papers, references, etc that can help ...
1
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0answers
140 views
Choosing Right Type of Filter for time series data
I am working on a temperature time-series data which is very noisy. I am trying to measure true low and ...
0
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0answers
29 views
Design of frequency sampled filter in matlab
I have written following matlab code for frequency sampled filter:
...
0
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1answer
49 views
Digital Tanlock carrier recovery loop
Iām currently trying to understand a digital tanlock carrier recovery loop for QPSK (for example)
I cannot understand how it works.
For example we an ideal QPSK constellation.
phi = atan2(Q/I) = pi/...
0
votes
1answer
89 views
What is the slope of a transfer function?
Lets say I have a Transfer function (H) plot as below. I need to find the SLOPE of the transfer function in dB/MHz.
That is... i need a plot (db/MHz) vs frequency.
How can i go about it ?
...
