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12 views

Algorithm Switch in Simulink

I am currently working on a control mechanism which looks as in the following figure: In general, I'd like the input1 (the one where only gain and integrator are present), if and only when input2 ...
3
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1answer
51 views

Extracting common signal from 4 sets of observations

I am working on a signal processing assignment where I need to find out one common time domain signal from 4 observation. The math is like this: \begin{array}{lcl} y_1(t) & = & a_1(t)*x(t) + ...
1
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1answer
64 views

How to analyse the sound of Motor

I have a motor, that I want to analyse, using its sound, so I can its 'character' I was using the the simple fft, and figured out, that it wouldn't help, so I tried the order analysis, at least I ...
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3answers
83 views

literature related to Spectral resolution

I am interested in spectral resolution of spectral estimation methods. Can you point me to some good literature, videos or books from which i can read and study? I want to understand how to resolve ...
2
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1answer
52 views

Detecting a curve with certain characteristics in a spectrogram

I have a spectrogram built by breaking a signal into chunks and taking the FFT of these chunks. An example spectrogram is: In this spectrogram I am looking for a curve (aka pitch contour) that: ...
2
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5answers
404 views

How to separate a low amplitude signal of same frequency but different phase

I have a signal consisting of two sine waves of same frequency but have different phase (and also a lot of hf noise). Their amplitudes differ by about 120dB. How to I go about separating them? SNR is ...
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1answer
100 views

Relationship between entropy and SNR

Dynamical entropy Kolmogorov entropy is defined as the supremum of the Shannon entropy over partitions of the phase space. In general any form of enropy is defined as uncertainty or randomness. In a ...
0
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1answer
63 views

Suggestions for FFT based tools to analyze music - Preferably MATLAB/free software packages [closed]

I am interested in analyzing full length songs for general features of the track which are not otherwise apparent. For e.g., I want to look at various parts of the song with time-frequency ...
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2answers
68 views

Suggested algorithms for detecting voiced / unvoiced signals [duplicate]

Right. I'm trying to understand the concepts for determining where the signal contains voiced and unvoiced parts. I have created a spectrogram (STFT) of a signal and I'm trying to separate from ...
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1answer
80 views

Classifier for detecting sound over noise [duplicate]

Suppose I have the following signal (Spectrogram): I have three types of elements that I want to identify within this signal: 1) Noise 2) Call-1 3) Call-2 I ...
2
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0answers
55 views

Segment/Idenfication of signal from a spectrogram

I have the following Spectrogram of a signal: Essentially, in this signal, I know there is one point of interest (between 60-80) and between the the particular frequencies. I could, potentially ...
0
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0answers
61 views

Prony method for undamped signal

i have one question related to sinusoidal model,as i know Prony's method for parameter estimation is used for damped signal,when amplitude of signal decreases as time varies,but is it relevant to ...
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0answers
41 views

Autocorrelation

I am attempting to use an autorrelation significant value indicating periodicity of a signal and use it as predictive variable in a regression. If e.g. significant autocorelation at frequency 3, does ...
2
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0answers
25 views

If test statistic is $T(\textbf{Y})=\frac{1}{N}\sum\limits_{n=1}^N |Y[n]|^2$ then what is $T(\textbf{Y}|H_1)$?

There are two hypothesis: $H_0:Y[n]=W[n]$. $H_1:Y[n]=X[n]+W[n]$. $X[n]$ and $W[n]$ are independent of each other. $W[n]$ is zero mean Gaussian with variance = $\sigma^2$; however we only know the ...
1
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0answers
34 views

determining walsh function components of signal after passing through non linear process

When a sum of sine waves is passed through a non linear process, harmonics and intermodulation distortion products are created, which are visible when applying an FFT to the signal. This causes ...
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0answers
34 views

Screening out important signals

I want to know if there is a generalized way to select a signal from a set of signals. Let me clarify it: I have a number of signals $S = \{S1, S2, S3,...\} $. Some of the signals are not important ...
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0answers
36 views

Train Pulse Recognition in Medium Voltage Networks

I just started a project in the Smart Grids area. It involves the recognition and quick extinction of earth faults in a medium voltage system. The system works automatically and pretty much gets rid ...
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1answer
14 views

How to detect if the given signal is Data or Clock signal type?

I have the edge information of the signal. I need to find if it's a Clock or Data type signal without iterating through all the points in edge vector... Please provide your valuable inputs
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1answer
88 views

Detecting presence of music in ambient sound

I am hoping to create an application that would listen to ambient sound and detect if music is being played. It is not important to identify the music being played; just detecting that some music is ...
1
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1answer
79 views

Most accurate method of Voice Activity Detection?

What is currently the most accurate Voice Activity Detection algorithm with high levels of background noise? I would also appreciate if it does not require any manual calibration. Bonus points for ...
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2answers
312 views

Polyphonic detection/Mulit-pitch detection/Chord recognition

I build application witch will be transform piano sound to musical notes. I found some pitch detection algorithms with implementations (mainly based on autocorrelation or fft), but chord recognition, ...
2
votes
1answer
47 views

Speech Overlap Detection

I’m trying to figure out how to go about differentiating between a single-voice speech and a multiple-voice conversation in which voices overlap. In other words – the moment of overlap is what I’m ...
3
votes
2answers
354 views

Noise reduction from very noisy audio

I am trying to write an algorithm that would automatically segment a piece of audio with bird calls recordings. My input data are 1 minute-long wave files and on the output I would like to get ...
0
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1answer
107 views

Envelope follower not smooth enough

With the following code, I get the "envelope" of a sound signal. However in the "envelope" there are small oscillations (high frequency) : it is not smooth enough... I imagine that it's possible to ...
1
vote
1answer
296 views

relationship between block size and detected frequencies in goertzel algorithm

I'm trying to use the goertzel algorithm to detect a pair of frequencies in a signal. The sample rate I'm using is 8000 hz, and the size of the incoming sample buffer is 60 samples. I have a large ...
1
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1answer
70 views

Detect signals degree of imbalance

I have got this question: let's suppose that I have three signals, representative of the same variable, but taken on three different component of a same device; in my case, three load signals, ...
0
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2answers
171 views

Conceptual question on least square estimation method

What is meant by Least square plus Gaussian method of estimating the parameters of an unknown system? I am aware of least squares in general but some works refer it as least square+gaussian method. ...
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0answers
29 views

decorrelating two image maps — reflected images from laser scattering

I am stuck on a research problem and do not know what kind of methods to use. I hope people in this forum can give me some good ideas, I've always had good brainstorming sessions here. My problem is ...
2
votes
1answer
162 views

How do you find signal similarity when one signal has zero values? Correlation alternative?

I'm using cross-correlation to look for a Barker code in a BPSK signal. It occurred to me that if I send out a zero DC valued signal proceeding the barker code, it won't affect the correlation ...
2
votes
2answers
166 views

Why does pulse-width modulation work?

When we apply pulse-width modulation (PWM) on controlling the brightness of a LED or the speed of a DC motor, is it the lag in our eyes that is responsible for the feeling of a continuous powering or ...
0
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0answers
48 views

White Gaussian Noise: a reality or fantasy? [duplicate]

White noise has infinite variance, whereas Gaussian random variable must have some finite-variance to exist. How do two disjoint phenomena co-exist? Help will be highly appreciated.
1
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0answers
62 views

how to detect the center frequency of a QRS complex in an ECG signal?

i want to design a filter that can effectively detect the QRS complex in ECG signal(whose Fs=360Hz) and reduce high frequency noise components. i want to know as to how the center frequency is ...
3
votes
3answers
258 views

Removing unwanted peaks from signal

I have a signal which looks something like: The 12 main round peaks is what I'd like to keep. However, the peak detection algorithm I apply is picking up the in-between noisy peaks. Any strategies ...
4
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2answers
151 views

Is there a way to reduce the covariance matrix of several source signals to the dominant source signal?

The problem I have can be seen in the context of DoA estimation or blind source signal separation and similar fields, where several source signals are observed by several antennas (or by an antenna ...
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1answer
161 views

Integrator and the multiplier in the Optimal Binary Detector

The optimal binary detector for asymmetric, equiprobable PAM pulse normally have structure as shown below, But I cannot understand what is the multiplier and the integrator using for. Why the ...
4
votes
1answer
102 views

How to detect underdamped harmonic signal?

I would like to ask what could be the easiest way to detect the presence and beginning (no more, no less) of under-damped harmonic signal in a collect of ultrasound data. I have some acquired data ...
3
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0answers
31 views

Intuition of Location on the Conic Axis TDOA solution

In an old paper "A New Approach to Geometry of Range Difference Location", there is a mathematical derivation that does not include any mention of the relationship to the underlying problem. In the ...
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1answer
81 views

Question about the Haar Wavelet transform

I'm trying to detect the presence of a sinusoid in 1/f noise conditions using the STFT and the DWT with Haar wavelets. I find this interesting phenomenon that I'm not able to explain (see plot at 1) ...
2
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1answer
106 views

Dealing with spectral leakage between two frequency bins

I'm looking for two signals embedded in very noisy data. I know they are close to periodic and integral with the run, but are rather close (30s and 21s during a 210s measurement), and our sampling ...
0
votes
1answer
76 views

Detect when someone has stopped talking

What's an extremely efficient way of detecting when a user has stopped talking into a microphone? When I use systems like Siri it can detect when I've stopped talking almost immediately, even when ...
6
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1answer
113 views

How to tell how likely a signal is present in another one? (variance unknown)

I know this is probably a simple question, but I haven't been able to find a satisfactory answer anywhere... Say you have a time series signal of finite length N. Call it $y[n]$. It is stationary, ...
5
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1answer
166 views

Received Morse Code signal-to-noise ratio?

I have some digital recordings of some received over-the-air CW broadcasts of known plain-text (W1AW code practice) at known WPM code speeds, but in moderate to heavy RF noise and fading. Can I ...
1
vote
1answer
468 views

Variance calculation from PSD

I have a receiver which is left to open for sensing. I'm using the periodogram method for estimating the PSD. I need to calculate the SNR of the incoming for which I need to calculate the variance. ...
5
votes
5answers
517 views

What are some methods for detecting a sinusoid in noise?

I'm looking for a broad classification on the kinds of techniques available. Something I can use to begin a literature survey. Some details: should be feasible for real-time implementation. Binary ...
4
votes
1answer
841 views

I and Q Channels

My understanding of I and Q channels is as follows (please correct me if I am wrong): I = In-phase, or real component Q = ...
1
vote
1answer
1k views

Showing frequency and amplitude after doing an FFT on a signal

I have executed an FFT on a .wav file of a person saying "ahhh" which shows the frequency and amplitude of the audio file. When I run it on a .wav file it shows the frequency 0 Hz as having the ...
3
votes
1answer
207 views

How to detect the edges of periodic signal?

I have a periodic signal generated by accelerometer sensor and I need to count the number of peaks. However, I can't predict when the periodic sequence starts and ends. What would be the best way to ...
1
vote
1answer
132 views

Hidden Markov Models - Identifying Phonemes

I'm developing a project that identifies Phonemes to be able to identify whether someone is saying either "Yes" or "No". So far in the project, I have used Zero-crossings to identify what the person ...
1
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1answer
89 views

Establishing the function of a decaying signal

I have a set of samples from a signal. The signal is erratic in behaviour at the beginning but then it settles down and oscillates around the value of 100 (the frequency of oscillation is not ...
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2answers
1k views

Add odd/even harmonics to signal?

How do I add odd or even harmonics to a floating point signal? Do I have to use tanh or sin? What I'm trying to do is achieve some very simple distortion effects, but I'm having a hard time finding ...