The tag has no wiki summary.

learn more… | top users | synonyms

-1
votes
0answers
9 views

embed a low-bitrate signal in a g.722 audio stream

I would like to embed a small code (<16 bits) in an audio stream such that it can be recovered after g.722 encoding. It is not particularly important that the code be inaudible, as long as the ...
0
votes
0answers
24 views

Problem in Implementing Cyclostationary Feature Detector in Matlab

I have Implemented this detector in AWGN channel in Matlab but I am getting vague result. As it performance doesn't vary with change in SNR. Its very strange result for me. I don't know what mistake I ...
0
votes
2answers
46 views

“Perfect waveform” for cross-correlations?

I am well versed in cross-correlations, as my masters thesis heavily relied on them for music classification and beat detection. So this question focuses more on the signals that I am running an ...
0
votes
1answer
53 views

Is it possible that adding noise to a signal can increase detection possibility?

I am simulating a feature detector in noisy environment which consist of AWGN Noise and Impulsive Noise. But I am getting a strange result as Signal with Impulsive+AWGN noise has better detection ...
1
vote
2answers
164 views

Simple and efficient algorithm to detect frequency and phase of a sine signal

I need an algorithm to detect frequency and phase of a pure sine signal. The frequency of the input signal changes between 0 and 100 Hz. The value of the signal gets captured with a frequency of 20 ...
-1
votes
0answers
11 views

2 input sound card for signal acquisition?

I want to use a dual input sound card for data acquisition as a project I'm doing. Does any body know of a suitable card? One that's readily available and not too expensive. 24bit sampling, PCI, and ...
0
votes
0answers
20 views

Adaptive filtering for detection of a known-frequency periodic signal

Given a very noisy signal (EEG recording), to identify which periodic component is stronger, out of $N$ (e.g. $4$) known frequencies. For the sake of completion, the application is an SSVEP-based ...
0
votes
1answer
55 views

Detecting a frequency swept sinusoid and its parameters?

Given a (FFT-sized) frame of data, and detection of a spectral component statistically above the noise floor in the FFT of this window, what characteristics or signal analysis could be used to ...
1
vote
1answer
71 views

Why these harmonics always present?

I am using Audio Precision 2700 to test some test vectors. I have connected resistor banks as class - d power amp's load, and tap from this resistor using a XLR cable to the AP. When my power amp ...
-1
votes
1answer
33 views

how to detect signal noise

I have data from a power transformer that has a frequency of 60 hz. Sometimes there are faults in the system and causes a large spike in the reading of the transformer. What I want to do is run the ...
0
votes
0answers
48 views

Simplest approach to classify signal based on its 'smoothness'?

First of all, I have no experience with signal processing whatsoever and I may not even use proper terms so please bare with me. I am just humble software developer trying to find the simplest and the ...
2
votes
2answers
83 views

Thoretically, what makes multi-pitch detection so difficult?

For multi-pitch detection, I mean for example pressing several piano keys at the same time. For signal pitch detection (pressing one key at a time), after FFT, mostly the frequency with the largest ...
1
vote
0answers
22 views

Variation in Signal Power in Mimo system

I am exploring methods for reducing computations required by MUSIC (Multiple Signal Classification) Algorithm. Most of the computational power is spent on calculating SVD. My approach is to take ...
3
votes
0answers
55 views

Incorrect Frequency results when using Multiple Signal Classification (MUSIC)

I am using MUSIC (Multiple Signal Classification) to determine Direction Of Arrival (DOA) and frequency of signals impinging on an Antenna Array. I am using a function ...
4
votes
0answers
77 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
51 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
386 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
64 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
42 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
69 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
2answers
158 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
109 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
63 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
53 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
274 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
39 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
272 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
126 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
37 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
62 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
90 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
112 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
60 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
728 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
261 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
84 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
87 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
91 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
71 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
82 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
49 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
37 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
37 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
60 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
16 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
101 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
92 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
859 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
53 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 ...