Questions tagged [signal-detection]

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5
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2answers
960 views

How to calculate the phase shift AND time delay of non-periodic signals

Say I have two non-periodic signals, $f_1(t)$ and $f_2(t)$, with Fourier transforms $F_1(\omega)$ and $F_2(\omega)$. Basically, I need to line up $f_1(t)$ and $f_2(t)$ as close as possible, and I am ...
4
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0answers
95 views

Finding the parameters and endpoints of a sinusoid

Suppose I have some signal $$ s(t) = n(t) + \left\{\begin{aligned} &0 &&: t < t_0\\ &A e^{i (2 \pi f t + \theta_0)} &&: t_0 \le t \le t_1\\ &0 &&: t > t_1 \...
4
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0answers
803 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 ...
3
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0answers
28 views

Inconsistant Variation in BLE Beacon RSSI Values for Distance Measurement

I am developing an application to estimate the distance to a BLE Beacon using its RSSi values measured from a Mobile Phone. But when I started to collect data I could see that they varied so much that ...
3
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0answers
148 views

Multilateration of Sound in 3D Space

TL:DR - How can you find the 3D coordinates of a emitter than transmits an impulse signal? STORY: I'm working on something to improve my bird-watching. I've got a camera that can take pictures of ...
3
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0answers
96 views

Energy Detection in Presence of Colored Gaussian Noise

Before asking my question, let me introduce the context: For spectrum sensing based on energy detection, which has been widely studied in presence of AWGN, the optimal detection threshold is computed ...
3
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0answers
636 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 ...
3
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0answers
247 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 ...
3
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0answers
59 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 ...
2
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0answers
36 views

What does minimum entropy deconvolution mean?

I want to use minimum entropy deconvolution method to analyse vibration signals to detect bearing characteristic fault frequencies. I am confused as to what the meaning or exact definition of minimum ...
2
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0answers
14 views

Fast ICA : recover the sources with their mean after prewhitening

I want to apply the FastICA algorithm on a certain dataset. I believe the sources the Fast ICA can recover are able to explain other data as well (in similar way to factor analysis). However, I also ...
2
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1answer
44 views

Telling apart a right traveling non-periodic signal from a left-traveling non-periodic signal, with a background periodic signal

I have a time-signal sampled over a one-dimensional spatial domain $x$. I know it is made of 3 components: a right traveling non-periodic wave (characteristic time width $T_{R,NP}$, mostly 0 outside ...
2
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0answers
37 views

How to remove varying noise from strain data in MATLAB

I'm very new to signal processing. I have some data measured over time at 800 Hz. I'm interested in the high frequency signals. You can easily identify them in the image below (in this case, 3 signals)...
2
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0answers
67 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 ...
2
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1answer
56 views

BER performance of fractional equalizers for colored noise

I am trying to compare the BER performance of fractional and symbol spaced equalizers for channel equalization in colored noise scenario. I have found from simulation that for positively correlated ...
2
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0answers
61 views

Is there in signal processing similar method than Otsu's method in image processing?

I'm just wondering that is there any similar method for separate signal and signal+noise in signal processing like otsu's method set threshold to valley of image histogram? And if there is how can I ...
2
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0answers
539 views

Peak detection techniques

I'm using a cell-averaging constant false-alarm rate (CA-CFAR) detector to detect peaks like the first one in the following plot: The magenta line is the adaptive threshold, which is the local ...
2
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0answers
54 views

Supervised instrument recognition

Is it possible to use NMF for a sort of supervised polyphonic instrument recognition? I have training data for a timpani and training data for a bongo (or a bongo, snare and box drum). How can I ...
2
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0answers
46 views

Signal conjugation detected on RF recording samples, why?

I collected spread spectrum signals at 400 MHz at low elevation angles using Software Defined Radio complex sampling over the seasons. I noticed that over watery, icy surfaces, the RF samples are ...
2
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0answers
108 views

Is there a way to apply blind source separation using ONE mixture?

This question is a follow-up for my previous one: Reduce the "glare" effect of a receiver within a system. I have broken the problem into pieces and I humbly think that I've got a way to ...
2
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3answers
163 views

Signals - question due to sampling

I don't have an idea how to start it. Help pls :) $$m = z(t) + \frac{\operatorname{Sa}(t-T)}{4}$$ We have some signal $z(t)=\left(\operatorname{Sa}(\frac{t}{T})\right)^2$. How often the m signal ...
1
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0answers
24 views

If a function has slowly varying amplitude and phase what is the bandwidth of the amplitude and phase individually?

I am dealing with time histories that are narrow band with slowly varying amplitude and phase. I wish to extract the amplitude and phase but there is noise on the time history. An example of the type ...
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0answers
66 views

Blind STBC question

I am working on blind identification of the physical layer parameters of a particular protocol. Everything was going well until I got to the MIMO part. The system contains two transmitter antennas and ...
1
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0answers
27 views

How can I automate the calculation for P and I coefficients of an FPGA-based digital PLL?

I am working on designing an FPGA-based PLL through an NI myRI0-1900 FPGA and LabVIEW software. I have been able to create a functioning PLL with a PI loop filter, and but I found functioning P and I ...
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0answers
46 views

Detecting complex signal within complex AWGN using Neyman Pearson statistic

I need to construct a Neyman Pearson statistic for detecting a complex signal with known amplitude and unknown phase in additive complex Gaussian noise. My hypotheses are: \begin{align} \mathcal{H}_0 &...
1
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0answers
24 views

Threshold Estimation from a Linear FM Pulse Position Modulated signal

I have a signal chain to detect multi channel LFM (Linear Fm - Hann window being applied as shaping filter for the pulses) pulses as shown in picture below. (Numbers in the picture is in Hz., for ...
1
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2answers
66 views

How to detect a signal while ignoring another signal which is a phase shifted version?

I have a signal coming from a sensor as shown below. This signal has high frequency noise (as can be seen from small fast wiggles) and four regions of interest where distinct spikes can be seen. The ...
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0answers
49 views

How to detect offset that changes along time in a signal?

I have an issue that has to do with detrending a signal. First, it seems my signals behaves a little unusual (for me, I think). Some signals starts with a quite large offset, then it seems to ...
1
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2answers
68 views

Algorithm for detecting whether a signal stored in rolling buffer is Increasing, Decreasing or staying Constant

I have a data signal which is generated at constant time interval. It is a real world measurement and thus exhibits some noise in its value (it fluctuates approx + or - 20 units). The noise is fairly ...
1
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0answers
56 views

MFCC parameters for gunshot recognition

I'm writing a gunshot detector software. I'm using this article as reference:https://arxiv.org/ftp/arxiv/papers/1706/1706.08759.pdf. For now, my software is able to recognize an impulsive sound. Now, ...
1
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0answers
106 views

Extracting signal from data using Otsu thresholding in MATLAB?

I am very new to signal processing. I am trying to extract a signal from my data using otsu threholding but it's not fully accurate. In this case I know that there is going to be a single signal in ...
1
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0answers
87 views

Is there a situation when maximizing SNR doesn't also maximize probability of detection?

The problem I'm working on is signal detection of a radar signal, but I suspect this problem shows up in many different branches of signal processing. Background: From [1], the factor $I_f$, by ...
1
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0answers
43 views

Required number of measrments for signal recovery in a compressed sensing MMV problem?

For multiple measurement vector (MMV) problem $Y=AX$ where $A$ is $m \times n$ sensing matrix and $X$ is $n \times L$ matrix haveing K non zero rows. What are the necessary conditions on the ...
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0answers
71 views

Sufficient conditions for exact signal recovery using OMP?

For a compressive sensing model : $$y_{_{MXN}}=A_{_{MXN}}x_{_{NX1}}$$ where $x$ is $K$ sparse, what is the sufficient condition for Orthogonal matching Pursuit (OMP) to exactly recover the data for ...
1
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0answers
46 views

Source localization in 3d

Let's say I have a 4-sensor square-shaped array in 3d space, with sensors at $$ s_1 = [1 \ 0 \ 1] \\ s_2 = [2 \ 0 \ 1] \\ s_3 = [1 \ 0 \ 2] \\ s_4 = [2 \ 0 \ 2] \\ $$ And a single source somewhere ...
1
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0answers
543 views

How to detect overall error between two signals and also track changes occurred

I need to develop an algorithm that will compare two signals (1 Reference Signal and other is measured signal values from sensor) and generate some metric(s) to describe changes between them. I am not ...
1
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0answers
124 views

Best Method to Separate square wave and smooth wave

I have a signal consists of a smooth wave and square waves. Is there comprehensive method can separate square wave and smooth signal? I looked for the likelihood ratio test but cannot find any ...
1
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0answers
25 views

Classification test by embedding true positives in high frequency recordings

I'm evaluating a cyclostationary approach to signal classification. My first step in doing so was generating signals and embedding them into a few specified parameter sets of the Watterson channel ...
1
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0answers
841 views

Detecting delay and sample drift in audio files (wav, mp3, etc.)

In my application, I have an audio recording with background music. I know which song is playing in the background and have a copy of the original song (wav, mp3, etc.). The goal is to align the ...
1
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0answers
48 views

How does the error in azimuth angle vary as one moves away from the boresight direction of a radar

My question is basically same as the title. I am trying to find a mathematical model which provides the error, $d\theta$, in azimuth angle($\theta$) as one moves away from the boresight direction of ...
1
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1answer
504 views

How to convert the mean and variance of a processed received signal into a SNR or BER?

So I'm trying to eventually get some sort of signal quality metric, and to do that, I'm trying to take the mean and variance of my bit determination signal and use that to come up with a Signal to ...
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0answers
97 views

Received signal envelope PDF to power PDF [Wireless Communications]

I am deriving the probability density function (pdf) of the received wireless signal envelope in multi-path fading channels. I wish to transform this envelop PDF to the power PDF of that signal. I ...
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0answers
268 views

Can we use SVD to solve single channel deconvolution problem?

I have seen using singular value decomposition (SVD) to solve deconvolution problem for example truncated SVD (TSVD) . It appears there is also a connection between Tikhonov regularization and SVD. My ...
1
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1answer
149 views

Detecting expected patterns in repeated measurements

I am new to signal processing and I am trying to learn myself. To understand what i am interested in, let me show this on example (note that this is just a random example to illustrate). Here is some ...
1
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0answers
323 views

Event detection in a running person's acceleration data

I am trying to detect some events on this signal : This is the acceleration of someone running. By eyes we can detect many blocs, sometimes separated by a little interval. I would like to be able to ...
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0answers
379 views

Audio - TDOA and $\tt xcorr$, find the 'best' peak

I try to locate a mobile device using multilateration. The mobile device acts as the receiver and in the room I have three speakers. To calculate the position I need the time difference of arrival (...
1
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0answers
110 views

Detecting special points in signal

What tool/filter/mathematic operation would you use to detect the red points marked in this signal? As you can see there are several differentiated groups and I want to detect those moments in which ...
1
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0answers
470 views

What is the best algorithm to detect leading edge?

I am interested to detect leading edge of one dimensional signal. There may be several algorithm for edge detection, specially for image processing (2 dimensional), but my interest is on one ...
1
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0answers
67 views

General question on signal processing guidelines for emergency shutdown applications (i.e. medical devices)

Disclaimer This might be a very broad question. I ask it out of curiosity, because the topic came up in a discussion lately. Hence, I do not have any specific applications or even data that I could ...
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0answers
46 views

How do I correctly receive a signal using a signal analyzer?

For the past few weeks, I have been trying to send a Zaddof Chu signal using a vector signal generator, and receive it using a signal analyzer. Both devices are made by R&S. However, the signal ...