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3
votes
0answers
37 views

How to classify accelerometer data?

I am trying to detect if a car did accelerate or did brake by using the accelerometer of the iPhone. In the figure below I plotted the collected data. (To collect the data the phone was laying flat ...
0
votes
1answer
39 views

Advice on filtering a CW signal for processing

This question is related to my other recent questions. In the last question, I learned that I should filter about 4 * WPM (words per minute) around the carrier frequency if I want to recover Morse ...
2
votes
2answers
355 views

Why do some radio stations still use amplitude instead of frequency modulation?

Why is frequency modulation (FM) not used on the current amplitude modulation (AM) radio stations? The Police have FM 2 way radios that use only 5 kilocycles of modulation. Instead of the current AM ...
1
vote
1answer
50 views

Effect of noise and entropy

Relation of Entropy and SNR : Based on this question and answer, I had another question that struck me and I am curious to know, if somebody can shed some light, on the following situation: $y= ...
2
votes
0answers
39 views

Is there a way to apply Blind Source Separation Using ONE mixture?

This question is a follow-up for my previous one: How to reduce the glare on a receptor with little info on the signals?I have broken the problem into pieces and I humbly think that I've got a way to ...
0
votes
1answer
68 views

Reduce the “glare” effect of a receiver within a system

I'm working this summer on a very interesting, albeit difficult to understand at 100 %, project and it turns around reducing the glare effect than could be applied on a receiver when he gets signals ...
0
votes
1answer
85 views

Detecting sound inside a sound

I was searching on the Internet hopelessly about some materials regarding detecting a sound in another sound. Say, I've got a recorded short sound (which may be anything, fragment of speech, fragment ...
1
vote
2answers
88 views

When should we using moving average in algorithm design?

I'm new to signal processing. And I just read G.720.1. I find there is a lot of moving average used. And I can also recall there is a lot of moving average been used in other audio processing ...
2
votes
1answer
54 views

Is step detection the correct approach to this problem? what if not?

I'm looking for some advice on where and what to start reading for learning to solve this. I've the time series of the position coordinates (x,y) of an animal in an open field (just a cage). I want ...
0
votes
1answer
52 views

best meathod to lock onto a cdma signal?

I've been looking at 2 different methods to acquire a known prn code in a CDMA signal. The first trys Xor prn code chip to I sign data. Then average the result over a time period to determine the data ...
7
votes
1answer
240 views

Ultrasonic signal detection

I have created a fairly simple TDOA system that uses ultrasonic signals emitted from two speakers to geolocate (relative to the speakers) mobile phones. The two signals are separated by frequency. ...
1
vote
1answer
34 views

Low frequency and high frequency noise of ecg

Is baseline wander in ecg is low frequecny noise in ecg and power line interference is high frequency noise in ecg? Is both the artifacts present in EMG signal?
2
votes
2answers
229 views

How to quantify asymmetry of a signal?

I'm looking for a suitable measure in order to quantify the asymmetry of a signal. I've read this: Detect signals degree of imbalance and this: How to measure the agreement between to curves? but I ...
0
votes
4answers
91 views

Can Morse Code be encoded using “silence” for dots and dashes?

Morse code dots and dashes are often displayed as a sound, or light that is on for a short or long period of time. What if the only way to communicate was by knocking.... (or similar encoding) that ...
0
votes
0answers
24 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
votes
1answer
59 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
vote
1answer
76 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 ...
1
vote
3answers
101 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
votes
1answer
57 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
votes
5answers
609 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 ...
7
votes
1answer
185 views

Relationship between entropy and SNR

In general any form of enropy is defined as uncertainty or randomness. In a noisy environment, with increase in noise, I believe that entropy increases since we are more uncertain about the ...
0
votes
1answer
81 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 ...
-1
votes
2answers
76 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 ...
-1
votes
1answer
85 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
votes
0answers
64 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
votes
0answers
78 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 ...
0
votes
0answers
43 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
votes
0answers
26 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
vote
0answers
36 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 ...
0
votes
0answers
36 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 ...
1
vote
0answers
45 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 ...
0
votes
1answer
15 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
1
vote
1answer
93 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
vote
1answer
84 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 ...
0
votes
2answers
587 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
50 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
628 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
votes
1answer
139 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
368 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
vote
1answer
78 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
votes
2answers
178 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. ...
0
votes
0answers
31 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
175 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
179 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 ...
1
vote
0answers
50 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
vote
0answers
72 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
292 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
votes
2answers
193 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 ...
1
vote
1answer
205 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
112 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 ...