The signal-detection tag has no wiki summary.
3
votes
3answers
75 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
84 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
47 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
50 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
votes
0answers
23 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 ...
0
votes
1answer
47 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
votes
1answer
57 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
46 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 ...
4
votes
0answers
66 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
votes
1answer
125 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
113 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. ...
2
votes
0answers
60 views
Voice sample prediction scheme
I have some telephone voice audio with occasional "blips" in the audio. The blips appear to come from an IP link buried in the PSTN (this is a conceptual explanation, so don't worry about things like ...
5
votes
5answers
242 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 ...
3
votes
1answer
176 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 = ...
0
votes
1answer
461 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
146 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
88 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
vote
1answer
74 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 ...
8
votes
2answers
575 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 ...
0
votes
0answers
216 views
Zero-Crossings vs FFT
I'm trying to strip an Audio signal to identify different Phonemes in the sample.
I have read a tutorial online that states that the Total Energy at different time intervals can be used to measure ...
2
votes
2answers
103 views
How to create a test to measure end to end audio delay
Lets say I have a program like Skype and I call to my friend. I want to create a test to figure out what is the average delay from the audio, from my mic to his speakers.
I want to measure:
delay ...
3
votes
0answers
72 views
Recovering signal for psk
I am currently working on a product(cant disclose too much details of the actual project) in which some data is being sent via audible(but on the higher freq) sound that is encoded with dqpsk.
...
3
votes
1answer
119 views
Identifying the age of a speaker using speech recognition
I am just wondering if it's possible to gather the age group of someone speaking in a sample?
For example, could I tell whether the sample is a child, teenage, adult, etc?
4
votes
1answer
143 views
Generating good synchronization sequences
As part of my work I am putting together a simple bursty BPSK communication system. I want to make the demodulation easy, so I am going to put a synchronization sequence at the beginning of each ...
1
vote
1answer
71 views
HMM's - Possibility?
I have a basic understanding of HMM's and as a final year project at school wanted to expand my knowledge further.
My basic idea was to create an algorithm that determines if someone is saying ...
2
votes
3answers
309 views
choose the length of signal
I'm trying to transforming an already know signal from time domain to frequency domain using FFT function in Matlab. And I got different values of amplitude when I change the value of length of signal ...
2
votes
1answer
125 views
Spectrum and Spectrogram explanation
I'm reading this material but I don't understand this example:
"An example of a 94% overlap transform processing could be demonstrated by a 279 sample frame with 262 samples overlapped from each ...
2
votes
3answers
593 views
Window function and length of signal
I'm new to FFT and DSP and I want to ask you some questions about calculating FFT in Matlab. The following code is from Matlab help, I just removed the noise.
What happens if I choose the length of ...
2
votes
0answers
190 views
calculate root mean square, ratio of power, constant false alarm, … of a signal
I am new to Digital Signal Processing, and am reading a paper. I don't know how they can extract some features from signal, like root mean square (RMS), Constant False Alarm Rate - CFAR, Mean Value ...
2
votes
1answer
192 views
Acoustic feedback detection algorithm
I am woking on an sound processing application where I have limited processing resources. I need to be able to detect acoustic feedback and then signal that such an event occurred. I am not concerned ...
4
votes
1answer
122 views
Generating a signature to identify RF modulation types
Thanks to the Realtek 2832U I'm just discovering the world of Software Defined Radio. There are a lot of signals I'm able to pick up with this device, but identifying them is not always easy and ...
5
votes
2answers
105 views
determine two signals with a scale factor
Suppose I have 2 signals from function $f_1(x)$ and $f_2(x)$, respectively, and assume the sampling rate is above Nyquist frequency, so we can restore the underlying functions $f_1(x)$ and $f_2(x)$. ...
6
votes
1answer
106 views
What is averaging and how can it be done?
I'm studying about the analysis of (mainly) fMRI and EEG data. Multiple times it's mentioned that to reduce noise, you can use averaging, but nothing more detailed than that.
There never is literally ...
3
votes
0answers
360 views
Scipy - Audio Processing
I looking for good tool for Audio signal processing. e.g Speech & music analysis, identification.
Does scipy provide functions for audio processing? Is this a good tool for Audio Signal ...
6
votes
1answer
348 views
Match Filter in Time-Frequency domain instead of just Time domain. Redundant, or better?
Assume you have a signal, and within it, some pulses are present. A pulse is a simple tone. You know the pulses' duration, and shape. (Let us assume that a pulse is made of a couple of cycles, and ...
4
votes
4answers
106 views
How to measure a detector's performance under extremely complex real-world environment?
I am trying to formalize my understanding of how best to measure the performance of a binary detector. (See previous question here). I had looked into ROC curves for doing this however based on ...
3
votes
1answer
132 views
Questions on the generation of R.O.C. curves
In my foray into detections, I am trying to understand how best to generate receiver operating characteristic (ROC) curves, and some questions have come up.
In my studies, I have found out that ROC ...
5
votes
2answers
357 views
What statistic is used to determine presence of a signal in noise?
This is a detector problem I believe:
I am being stumped by what appears to be a simple problem. Basically, I have a band of interest. If signal energies exist within this band of interest, then I ...
7
votes
2answers
256 views
How to define SNR for multiple signals in noise?
I have to estimate the number of signals present in a measurement contaminated by additive noise given $n$-dimensional snapshot vectors $\bf x$, modeled as $ \bf x = \bf A \bf s + \bf z $ where $\bf ...
6
votes
1answer
269 views
Efficient frequency offset estimation of known signals
Let's say that my receiver will be receiving known data signals that range from the very simple (tone) to the complex (known data sequence that is modulated (PSK/QAM/OFDM/etc.)). What are the most ...
