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Questions tagged [signal-analysis]

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17
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3answers
3k views

Show others how I hear myself

Sooo .. I've been thinking about this stuff. We all know that we sound different from what we hear of our own voice. It is easy to find out how others hear us by recording oneself and listen to it. ...
1
vote
1answer
76 views

Can a Fourier Transform exist even if the j$\omega$ axis is not in the Region of Convergence in it's Laplace Transform

A couple of confusions have been occurred. The Signal I'm considering is f(t) = sin(t)*u(t) Fourier Transform of it can be derived. $-i \pi (\delta (\omega -1)-\delta (\omega +1))$ According to my ...
1
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0answers
87 views

How to envelope a non periodic Impulse signal?

I want to analyse a trc oscilloscope file, find impulses and envelope them. In the end I want to plot the envelope. data file (trc): https://ufile.io/z4m4d Code: (Python) ...
-1
votes
1answer
17 views

When does a color channel such as RGB carry more info than a grayscale channel or image?

Typically a gray-scale image gives us more information about an image in terms of a signal processing problem. But when does a color channel carry more info than a gray-scale channel? I understand ...
0
votes
1answer
28 views

EEG Sampling, Which Order should cover my result?

I have EEG data sampling rate is 250 Hz and I want to band pass this data in ( 0.5-3 Hz & 3-8 Hz & 8-13 Hz & 13-30 Hz & 30-40 Hz). Currently, the data is in the frequency range of ...
0
votes
1answer
30 views

What's the point of using Morphological processing concerning images?

I dig deeper in internet to figure out what's the point of morphological processing on images, but i'd rather to hear the answer from people with experience, can you give me a hand with this? Thank ...
0
votes
1answer
62 views

Are resolution increase and noise reduction from oversampling mutually exclusive?

Oversampling a signal means sampling it with a significantly higher sampling frequency than the Nyquist rate. As far as I know, there are three advantages: Easier design of anti alias filter Increase ...
1
vote
1answer
50 views

Spectral averaging without phase information

In the context of signal averaging to reduce uncorrelated noise: Is it possible to perform signal averaging from just the magnitude spectrum of certain signals? Or that would only work if we know ...
0
votes
1answer
22 views

Characterization of the amount of modulation in a signal

We have used the ICRA babble noise to generate an 8-talker babble. As a background - babble noise is used as a substitute for competing talkers as babble noise lacks lexical content, but contains the ...
0
votes
1answer
70 views

Figuring magnitude and phase response

I've got a linear time-invariant system $$y[n]=\frac{8}{9}y[n-1]+x[n]$$ which I transformed into a transfer function $$Y(z)=\frac{8}{9}Y(z)*z^{-1}+X(z) =>\frac{Y(z)}{X(z)}=\frac{1}{1-\frac{8}{9}*z^{...
0
votes
1answer
89 views

How to determine fundamental frequencies (beats/minute) of heartbeat? (matlab)

read = matfile('ECG.mat'); [cor, lags] = xcorr(read.ecg, read.ecg); read.Fs; So i have read.ecg (signal) and ...
3
votes
1answer
48 views

Compare two signals, find times when they are affected by the same processes

I have two (noisy) signals $S_1(t)$ and $S_2(t)$. They contain information on three distinct events occurring in a physical system. Event $A$ affects only $S_1(t)$, event $B$ affects both $S_1(t)$ and ...
0
votes
1answer
121 views

What is the difference between Spectrogram and Scalogram?

Could someone please explain the difference between the two? Spectrogram: A visual representation of the spectrum of a sound changing through time. Scalogram: (signal processing) A visual ...
2
votes
1answer
68 views

Denoising a signal using eigendecomposition

I have a complex observable series $Y(t)$ which is the result of summing two complex r.v $X(t)$ (unobservable) and a $\epsilon(t)$ (unobservable). $$Y(t)=X(t)+\epsilon(t)$$ Assume that $X$ and $\...
0
votes
1answer
110 views

How to compute the channel gain from the path loss model of a wireless channel

I did my research but I did not get a satisfying answer. We have a transmitter and a receiver over a wireless communication channel. The channel's path loss is modeled as $ 128 + 37 \log_{10} (d)$, ...
0
votes
1answer
46 views

How to find the coefficients of the following differential equation

An arbitrary signal $v(t)$ pass through the following system, $w'(t) + 5 w(t) = v'''(t) + 320v''(t) + 40 v' (t) + 40v(t)$ How to determine the coefficients of the following differential equation, ...
2
votes
1answer
73 views

Linear Predictive Coding for general signals

I have a signal that's monotonic and roughly linear and have been looking at using Linear Predictive Coding to encode information and compress my signal. I guess my first general question is if this ...
-1
votes
1answer
21 views
0
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2answers
50 views

Accurate description of the spectrum of sinusoid waveform added with WGN?

The transmitting signal is $$ s(t) = \sin(20\pi t)+\sin(40\pi t)+\sin(60\pi t) $$ The received signal after AWGN channel is $$ r(t) = s(t)+n(t) $$ where the variance of noise $n(t)$ is $\sigma^2$. ...
1
vote
0answers
39 views

Frequency bins too powerful at the start and at the end of each sample computed DFT data

I've taken the following link http://coding-geek.com/how-shazam-works/#comments as a project to start practising and learning signal processing and python programming for me to get started in speech ...
4
votes
3answers
268 views

Is Linear Prediction ever exact?

I'm just learning about linear prediction and was wondering whether or not there are any signals that would produce no error if run through a linear prediction algorithm. I was thinking (maybe naively)...
2
votes
0answers
39 views

FFT Service on AWS? [closed]

Hopefully this is the right forum to post this question. Initially posted to Meta. My mistake. Learned the hard way via downvoting. I searched AWS and Microsoft cognitive services for an FFT web ...
1
vote
1answer
33 views

make a voice sound signal play faster

Suppose $x(t)$ is a signal containing a voice. How can one derive a signal playing the same voice faster. I tried $x(t+\lfloor{100t\rfloor}/100)$ to double the speed; But it adds a buzz sound. Is ...
1
vote
1answer
65 views

GPS Coarse Acquisition PRN Codes

Are the actual 1023 bit sequences for each of the 32 GPS satellites available to consumers? I found the IS GPS 200 but it doesn't list the entire sequences. Are verified sequences available for ...
1
vote
0answers
49 views

How to estimate noise by eigendecomposition of the variance covariance matrix?

I'm new here so I will try to be as clear as possible. I am trying to apply some techniques from signal processing framework to denoise financial time series. I would like to know if what I am ...
1
vote
1answer
320 views

Practical book in C [duplicate]

Is there any practical “go to” book that demonstrates the main dsp methods for time series written in C for practical applications? (Doesn’t have to be for hardware, but for any raw data such as ...
-2
votes
1answer
49 views

Signal reconstruction from sampled signal? [closed]

Can we construct exact analog signal at receiver as same as the source from the sampled signal?
0
votes
1answer
55 views

Implementing real-time signal processing filters

I’m currently working on my capstone for school, and I’m looking for some guidance/tips when it comes to real-time filtering. The nature of the project is to monitor breathing patterns, send the ...
0
votes
1answer
41 views

Signals and Systems - LTI - Transforms - Impulse Response

I have $x(t)-> LTI -> y(t)$ where $LTI=h(t),H(jw)$. and $H(jw)=ab/((a+jw)(b+jw))$ where a and B are real numbers. I am wanting to find the impulse response $h(t)$ as well as the input/...
0
votes
1answer
35 views

Find identical audio signal

I have a long audio file (in wav) and a short audio file (in wav) that has been copied from the long file. Now I need to find the correct location where the short signal has been copied from. I tried ...
-2
votes
1answer
33 views

Frequency component not filtered properly

Are frequency components other than wanted signal present in the output? If yes then why does it not disturb the original signal? I think all practical filter responses are not ideal, so all frequency ...
0
votes
1answer
43 views

Real and Imaginary data from Network Analyzer

I’m having a hard time grasping what exactly ARE the real and imaginary numbers in my s-parameter data. Most of the time I just set the NA up in logmag/phase to find the loss though, say, a filter or ...
1
vote
1answer
102 views

Finding audio “tics” in stereo wav files using python

I have thousands of audio files that I want to "batch" process searching for audio tics. This is easily done using a DAW but that requires opening each file independently, searching for the tic (...
0
votes
1answer
35 views

Equalization : using the spectral or the temporal signal?

I'm trying to equalize a sound signal - using a JAVA program - and I'm using this process : 1/ Conversion of the temporal signal to a spectral signal, using a FFT 2/ Applying a coefficient to each ...
1
vote
1answer
75 views

Damped sinusoidal form FFT of signal

I'm doing an assignment for the course Signal analysis where I have to analyse a signal. I've tried quite some things now but it's still bothering me that the FFT is looking weird, and not looks like ...
1
vote
1answer
37 views

Ways to parallelize Sifting in EMD (Empirical Mode Decomposition)

Sifting process, which is recursive in nature, is used in EMD (Empirical Mode Decomposition) to decompose the signal (x(t)) into Intrinsic Mode Functions (IMFs) and residue, which is a monotonic ...
1
vote
0answers
21 views

What is the signal-noise model of laser induced fluorescence?

The following image is an example of a fluorescence signal trace from the photomultiplier tube detector (PMT). Each spike represents one fluorescently labeled cell. This signal model is definitely ...
0
votes
1answer
62 views

What's the difference between SISO and SIMO in using matched Filters

Suppose we are transmitting a signal $x$ in $OFDM$ with $N$ subcarriers, After performing Parallel/Serial conversion and then N-points FFT, we suppose to have signal $s = IFFT^Hx$, Then adding the ...
1
vote
1answer
44 views

Why are binary signals drawn continuous in time despite being a digital signal

The conventional definiton of a Digital signal is as follows: A digital signal is a signal that is discrete in time and quantized in amplitude. Almost all resources (textbooks, online sources,etc) ...
0
votes
1answer
48 views

MMSE of X given PDF

"Suppose RVs $X$ and $Y$ with probability distribution functions $F_X$, $F_Y$, and $F_{XY}$. Find a linear estimate $\hat{x}$ of $X$ by the observed $Y$ such that $\hat{x}$ correspond to the minimum ...
-1
votes
1answer
50 views

Why do we need the power spectral density?

Since the power spectral density is just the squared of the fourier transform, why is it useful ? Can't I just replace every solution that requires the psd with the fourier transform ?
0
votes
1answer
64 views

Why must the Region Of Convergence (ROC) contain infinity and the system function be a right-sided sequence for it to be causal?

I need the simple logic on the condition a system becomes causal. We know that causal contains only past values. I can't relate this with the Region Of Convergence (ROC) concept.
1
vote
3answers
60 views

Significance of Sinusoidal signals

Can anyone tell what are the significance of sinusoidal signals in the field of science and engineering? sorry for being noob,
2
votes
2answers
111 views

GPS CA Signal Acquisition

The coarse acquisition C/A GPS signal has a symbol rate or chip rate of 1.023 Mcps with code period of 1 ms. The code bandwidth is +/-1.023MHz (to 1st sinc nulls). I'd like to record this signal using ...
1
vote
2answers
89 views

Simple way to determine square-ness of signal?

Not entirely sure if my term is correct. Feel free to edit title. I have a lot of time series, where the data quality is determined by how linear each sub-sequence is. It doesn't matter if it jumps ...
2
votes
0answers
47 views

ESPRIT signal subspace and rotational invariance

so in ESPRIT[1,2] we have some signal of the form: $$y[n] = \sum_{k=1}^{K} a_i(k) e^{j\omega_k n} + N[n]$$ where N is noise, then we get the autocovariance matrix $$R_{yy}=E[y[n]y[n]^*]$$ take the ...
1
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0answers
25 views

Audio analysis Implementation [closed]

I am supposed to implement some analyses for the customer including NB, WB, Time Domain etc. This is in the audio signal processing domain. The scope of work also includes "Audio Analysis". Can ...
1
vote
4answers
192 views

Difference Between Dirac delta and unit impulse function

The definition of Dirac delta function states that it gives a value of $\infty$ at t=0 and 0 elsewhere. But, the definition of unit impulse function states that it gives a value of 1 at t=0 and 0 ...
1
vote
1answer
50 views

Break a signal into segments, add them together and then perform an FFT on the result

If you break a 4 second signal into 0.5 second segments, add them together and then perform an FFT on the resultant 0.5 second data. Will the FFT / frequency spectrum be the simlar to an FFT on the ...
2
votes
0answers
39 views

How to visualize the autocorrelation matrix and it's properties

Having a hard time wrapping my head around autocorrelation matrix as it applies to a spectral estimation problem like MUSIC or ESPRIT. If the signal vector contains a summation of sinusoids in noise, ...