Questions tagged [signal-analysis]
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1,624
questions
0
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16 views
Residual carrier in PCM/PM/NRZ
As mentioned in the (Residual carrier tracking with PLL), residual carrier is created after PM modulation. I tried to do yhat in matlab softawre as:
NRZdata: -1 1 -1 1 1 -1 -1 ,....
theta = 0.5
PM ...
0
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1answer
14 views
If you would write the frequency-response in terms of projections through inproducts. How would you do it?
While studying for signals and systems I realised that the most intuitive way of understanding Fourier Series for me, was to see it as a projection (through inproducts) of a signal onto the orthogonal ...
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2answers
20 views
transmitting the real/imaginary parts of pass-band signal
As I know, the transmitted pass-band signal whose carrier frequency is $f_c$ can be written as follow:
$s_1(t) = \text{Re}(a(t)e^{j2πf_ct})$ , where $a(t)$ is the complex modulated base-band signal. ...
0
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0answers
16 views
Showing specific values in an STFT plot
I have a short term fourier transform plot that I plot using matplotlib's pcolormesh() function:
If I zoom in the plot, I see this:
Now, I want the plot to just ...
0
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0answers
9 views
Maximum Value of DSNR in Detection of Signals in Noise Second Edition
I am interested in problem 8.5 of Detection of Signals in Noise, Second Edition. The problem calls for finding the maximum value of DSNR. I have done so, but my solution does not agree with the ...
0
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0answers
26 views
Remove noise from VGA image
I have 2 color images generated from same X-ray machines, but one of the image is obtained using VGA cable. Therefore the RGB intensities differ in the 2 images. I am using Object detection to detect ...
1
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1answer
66 views
Finding the Sections of Signals that are the Most Similar
I have two discrete signals, $A$ and $B$ (both with $L$ values). I want to look for the section (of a certain length $R$) on each signal ($[A_1:A_1+R]$ and $[B_1:B_1+R]$) where they are the most ...
-1
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1answer
46 views
How to determine the shape along which an object is moving [closed]
The object moves as it pleases and receives its GPS coordinates.
How to determine which shape the object is moving along?
For example, we accumulated 10 points, processed them and produced the result: ...
0
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0answers
36 views
Reconstructing a signal from multiple filtered copies using overlapping tapered windows
I have an audio signal that I need to process and analyse in blocks. I've now decided to process it using overlapping non-symetric Hanning windows of length M = 9600 and a hopsize of R= M/2. I zero ...
0
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0answers
23 views
Legacy LongRange Mode information (mode 1 in the my attached link)
Mode 1- Legacy Long Range Packet Format and Im attaching a photo of ti reference:
link for more information about this mode category : TI SWRA642
I want to understand the packet format, what's my ...
0
votes
1answer
35 views
Calculating SNR of a complex-valued signal correctly
I have an array of complex-valued data. I would like to modify the array by injecting an artificial signal at a chosen Signal to Noise ratio.
I have seen the signal to noise ratio for complex-valued ...
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0answers
16 views
MPEG Audio Constant bit rate conversion
I am trying to convert few .wav files to .mp3 format
The desired .mp3 format is :
I tried with FFmpeg with this code :
...
0
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0answers
26 views
How to measure EVM?
I am trying to understand the concept of EVM and how it is measured at different points in transceiver. I have a basic understanding that the error difference is calculated between two vectors (i.e. ...
2
votes
2answers
149 views
Autocorrelation and Spectrum Density
Wiener–Khinchin theorem states that autocorrelation function and power spectral density are a Fourier-transform pair - see Wikipidia (and lots of other resources).
That means autocorrelation should be ...
0
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0answers
32 views
How to implement Walsh demodulation in matlab?
1 1 1 1 ==> 0
1 -1 1 -1 ==> 1
1 1 -1 -1
1 -1 -1 1
I have this sequence of walsh spreading ...
1
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0answers
54 views
Respiration (breathing) signal movement artifact removal
Situation: I have breathing data of participants who have done different things during the study which caused their breathing change; watching mindless video to which resulted in unconscious regular ...
0
votes
1answer
57 views
How to calculate variance of noise on a noisy image (Noise+Signal)
I have a long exposure image captured at 70ms. (I1) (As attached)
I also have another image captured at 0.7ms with Gain24. (I2) (As attached)
This image has both noise and signal together.
I would ...
0
votes
1answer
39 views
How to check my CRC of my RF packet? [duplicate]
The "problem" is that I want to validate if my received RF packet is valid or not valid, in other words I want to validate if my RF packet corrupted or not corrupted .
the transmitter that ...
1
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2answers
70 views
Output of marginally stable systems
In' b.p lathi's book of systems and signal it is written that
"marginally stable systems have one important application in the oscillator, which is a system that generates a signal on its own ...
0
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0answers
18 views
How NLMS/LMS adaptive filter used for noise reduction acts on input signal with low frequencies(DC offset/baseline wander)?
I am using Matlab to implement a real-time adaptive filter of length 4 for noise cancellation using the NLMS method/ I also tried the LMS method.
My aim is to denoise biomedical signals, and for the ...
0
votes
1answer
24 views
How to determine a suitable threshold when using amplitude thresholding method for spike detection?
I have seen number of approaches that have been introduced in the literature for spike detection including, amplitude thresholding method, Nonlinear Energy Operator method, and template matching ...
1
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0answers
29 views
Spatial frequency and video frequency of an image
in my lecture notes about image sensors (CCD, precisely) I have read the following statement:
The transfer function $F(\omega)$ of the image sensor is related to its spatial resolution function $F(\...
0
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0answers
28 views
Extracting rms delay, delay spread, and CIR from power delay profile
I have a spread spectrum channel sounder running the following transmitter and receiver:
When running it over the air (~2km), I get the plot of the correlator output:
I can see that there are peaks ...
1
vote
1answer
31 views
Power Spectrum analysis arbitrary length signals
I have signals belonging to diseased and healthy samples recorded from multiple electrodes. These signals are taken monthly and are of arbitrary length (say 4-5 mins). I am planning to do a power ...
0
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0answers
23 views
Calculate the percentage of accuracy with which user made the assigned sound
I want to design a web-app for my cousin who is 2 years of age in which i have implemented a functionality in which when an image is clicked some sound gets played and the user has to make the same ...
0
votes
2answers
44 views
Sine Dipole formation using two hydrophones
I am trying to do MATLAB simulations for generation of SINE Dipole using two hydrophones spaced distance 'd' apart for signal coming from direction 'DOA'. The MATLAB code is given below. The confusion ...
1
vote
1answer
64 views
Use of I/Q representation for unmodulated Rx Signal
it may be a stupid question but while learning about DSP and Modulation I was wondering, if the I/Q representation of an RF Signal is of any use, when the received signal does not contain any ...
0
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0answers
20 views
RMS and RMQ from PSD
From acceleration data I made a Power Spectral Density (PSD) and calculated the RMS via:
$$a_{RMS} = \left[\displaystyle\int_{f_1}^{f_2} a_{PSD}(f) df\right] ^{\frac 12}\tag{1}$$
Now, I want to ...
0
votes
1answer
25 views
Plotting a Time Frequency contour/colormesh plot of a Discrete Wavelet Transform
I have a pressure vs time data of a noise on which I wish to perform discrete wavelet transform.
I have divided my frequency range into 1/3rd Octave Bands and have calculated sound pressure level at ...
0
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0answers
32 views
Can largest-triangle-three-buckets downsampling method used with fourier transformed signal?
I've been reading on the largest-triangle-three-buckets downsampling method for downsampling. Though it was originally published in the thesis "Downsampling Time Series for
Visual Representation&...
0
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0answers
29 views
For an LTI system, the zeos and poles are defined in the z plane. How to add additional poles and zeroes so LTI system is real valued?
The question already has a zero and a pole in the complex plane. It is asking to add additional zero and pole so LTI becomes zero valued.
zeros=-1/2 + 1/2 i , poles = -1/3 -1/3 i .
What I understand ...
1
vote
1answer
43 views
What is the purpose of dividing an audio signal into segments and analysis each segment?
I read bunch of materials for extracting feature from audio signal and they all tell me to break signal into segments, why don't we analyze all the audio signal? I don't know what are the advantages ...
0
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1answer
46 views
Frequency Domain Distribution
I have a complex signal in the time domain normally distributed. What will be its distribution in the frequency domain?
I assumed since the frequency domain is a linear transformation the distribution ...
0
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1answer
29 views
What is the driving Voltage?
While I was looking into ultrasonic transducer in order to transmit and receive a beam, I came across specification of a transducer stating driving voltage as 20Vrms. I am not sure what actually does ...
4
votes
1answer
133 views
A-weighted Digital Filter for 1/3rd Octave Band Analysis
I want to do a 1/3rd Octave band analysis on a noise signal. But the sound pressure levels should be in dB(A), i.e., and it should be A-weighted.
For this, I am using the A-weight function from this ...
0
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0answers
35 views
Normalize two or more sound signals in order to let them with the same duration time and amplitude
I am very new in signal processing area and I am trying to solve the task in order to make an experiment with audio files from different languages, so, I am trying to let some ogg audio files with the ...
0
votes
1answer
36 views
Different number of modes while performing the EEMD (Ensembled Empirical Mode Decomposition)
I am performing an Ensemble Empirical Mode Decomposition (EEMD).
I wrote a MATLAB routine to perform the EMD. I noticed that when adding white Gaussian noise to the input signal, sometimes I obtain a ...
0
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0answers
26 views
How to deal with different audio formats for audio classification?
I am working on an audio classification problem statement to classify between two audio classes. I have collected samples from jotform, they are providing audio widget to collect .wav audio but it ...
1
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3answers
74 views
Meaning of sampling frequency?
Say there is a communication system, which can manage sampling frequency up to 4 MHz (given by software). Can the system be able to process signals with maximum frequency more than 2 MHz? Because ...
0
votes
1answer
37 views
What is the actual format of this audio file?
I am collecting some data from jotform .wav widget. All the audio files are in .wav format. But when I tried to open the file using python
...
0
votes
1answer
32 views
Accelerometer sensor's data analysis [closed]
Here is a sample data that I got from the accelerometer sensor:
The first selected area shows the acceleration of the IMU device to right side and the second shows the movement to left side.
I am ...
0
votes
0answers
24 views
RMS of signal vs average amplitude
I am trying to estimate the average amplitude of some signal with frequency 6 Hz, sampled at ~300 Hz. See figures for a part of the signal and its dft calculated using matlab.
I estimate the average ...
0
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0answers
17 views
Separation of a delayed mixtures of signals
I have three emitters in three different positions that emite three signals $S_1(t), S_2(t), S_3(t)$ with
$$S_1(t)=S_2(t)=S_3(t)$$
Two receivers recive $R_1(t), R_2(t)$ with
\begin{align}
R_1(t)&=...
2
votes
1answer
101 views
Separating/recovering base signal from two mixed signals, given phase information
I have collected two signals, $B_1(x)$ and $B_2(x)$. The signals start and end at the same $x$-values. Each signal $B_i(x)$ contains:
a base signal $b(x)$, which is the same for both, and
a signal, ...
0
votes
1answer
28 views
Having Problem about DownConversion
I hope, you are doing well. I want to ask question about baseband conversion.
Background:
I generated two AM signals in MATLAB, which one of them is shifted in time.
I multiply the signals with $\cos(...
1
vote
1answer
30 views
what is the relationship between the reliability of a monte carlo test and the length of the samples tested and the number of errors found?
Considering this setup, single tone transmission over a channel impaired by AWGN, doppler spread, and inter symbols interference.
We are to compute the BER as a function of the SNR.
We want to find ...
0
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0answers
19 views
Threshold Estimation from a Linear FM Pulse Position Modulated signal
I have a signal chain to detect multi channel LFM (Linear Fm - Hann window being applied as shaping filter for the pulses) pulses as shown in picture below. (Numbers in the picture is in Hz., for ...
1
vote
1answer
46 views
What the disadvantages of up-sampling
Let's say we have a signal $x[n]$ upsampled at the transmitter by $4$ and then downsampled at the receiver by $4$ too. As known, the performance will be much better compared with transmitting the ...
0
votes
1answer
35 views
channel estimation based on time-domain pillots
I am confused if it's possible to estimate the channel based on the time-domain pilots. I mean I have such signal $x$ with length $N$ after taking its $iFFT$ we get $X = ifft(x)$. I have perfect ...
1
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0answers
22 views
Why filtic function does not work for a specific use?
And how can I solve this issue?
I designed a filter via bilinear transformation in order to obtein a high-pass filter of Butterworth. When I want to set initial conditions with filtic function, it ...
