Questions tagged [signal-detection]

The tag has no usage guidance.

Filter by
Sorted by
Tagged with
-1
votes
1answer
36 views

Coherent Radar — How do we justify it?

How can we justify doing coherent radar when the phase of the return is unknown? For instance, after a reflection, assuming a stationary target, we should get something akin to: $$ x_{rx}(t) = |\...
0
votes
0answers
27 views

Python Time-Frequency Peak Filtering

I am very new to python and attempting to use the Time-Frequency Peak filter on a noisy. To begin I am trialling my code with a noise free signal. I have not reconstructed the signal yet. My question ...
0
votes
1answer
31 views

How to measure algorithmically side lobes in real data

I want to measure algorithmically the following parameters in a given FFT data (real numbers). peak side lobe levels side lobe levels 
side lobes nulls The following image illustrates parameters I ...
0
votes
1answer
21 views

I have the following accelerometer signal, I want to segment or slice the signal into Red parts and Green parts

I want to count steps which are basically represented by peaks in the signal. the red part in the signal doesnt correspond to any walking activity, I want to ignore them. Any help on segmenting or ...
0
votes
1answer
109 views

CIC Filter implementation for Normalized Correlation

This is a follow-on to the original post ... I am trying to implement real-time correlation of two signals. I noticed the CIC Filter discussion here: How to find correlation/cross-correlation of two ...
0
votes
1answer
39 views

Cone of Confusion

In sound perception, humans adapt by tilting the head or relying on other location cues such as visual input when the source of the sound lies on the cone of confusion. On this cone, no time and level ...
0
votes
0answers
18 views

interpretation of per survivor processing

Can any one explain me the interpretation of persurvivor processing, and how it is different from mlse,reduced state mlse,decision feedback mlse. What exactly meant by per survivor. Thanks in advance
0
votes
1answer
121 views

Correct comparison of FFT noise with FFT signal

I have a sensor which I am using to track a strong but noisy varying signal. When the signal is present there is a lot of energy in the FFT bins, when there is no signal the is much less energy - but ...
0
votes
0answers
26 views

Closed loop detection system

I am trying to design a detector of the DC component of a signal (low pass filter). I found the following topology (called Closed Loop Detection System) in an article (https://ieeexplore.ieee.org/...
0
votes
0answers
17 views

Detection time of a spur using FFT?

Say I have the following parameters, NFFT=2^14 Fs= 50 MHz main signal @ 22 MHz and its alias at 28 MHz at signal power -40 dbfs and a spur @ 2 MHz and its alias at 48 MHz Leave aside the alias's. ...
3
votes
0answers
20 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 ...
0
votes
1answer
51 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 ...
0
votes
2answers
429 views

How would you use machine learning for peak detection?

I have a noisy signal and I'm trying to find a way to detect peaks with ML. The "peaks" are easy to find as human because they are rhythmic and have the same "general" shape but the amplitude and ...
4
votes
3answers
416 views

How to Prove a System Is Invertible?

what i know is that for a system to be invertibel it should be one-one , but I am confused that if i am given a transfer function of a LTI system how can I prove or verify if it is invertible. ...
1
vote
0answers
31 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, ...
0
votes
1answer
43 views

Wireless Communication

Let's assume I send a root raised cosine pulse of 1ns at t=0 through a wireless channel. The power measured @ Receiver from t=0 is shown in image. Now from this image, I know that there are multipath ...
1
vote
1answer
79 views

Maximum likelihood estimation complexity computation

I have a basic question about maximum likelihood (ML) estimator and its implementation. I am trying to simulate a communication system, while using ML at the receiver side to find the transmit ...
0
votes
1answer
130 views

Time delay estimation between two complex signals(IQ)

I need to time align two complex signals. The two signals obtained were at different RF frequency before digitisation. So,I have two complex signals(IQ) and I need to do delay estimation and apply ...
0
votes
0answers
23 views

Is there a software/application that shows the FM base stations nearby us?

I want to collect a list of FM base stations near me. I have found apps/software for finding LTE base station but found no success in finding an app for FM base station.
2
votes
0answers
31 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)...
1
vote
0answers
46 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 ...
2
votes
2answers
98 views

How to identify the beginning and the end of a signal using MATLAB

I have multiple signals as shown in this image. I'd like automatically detect time for the earliest detection of the signal (approx 0.7e4 in S1-B3-B (orange)) and last detected occurrence of the ...
0
votes
1answer
80 views

What are the limitations of using Magnetic induction rather than acoustic communication in underwater communication

In underwater environment, Why acoustic underwater communications are still famous more than magnetic induction communication however in magnetic induction underwater communication, higher data rate ...
0
votes
0answers
41 views

Is it possible to analyze this microphone data and what to do if not?

I just created an account here because I really need some help. I'm using a microphone pmodmic3 with a development board called Ublox C030-U201 which uses the mbed OS. The microphone is working for ...
0
votes
1answer
47 views

Does flat surface detection and orientation require special hardware to compute?

Modern augmented reality platforms such as Google's ARCore and Apple's ARKit seem to only operate on mobile devices, I'm guessing, because their underlying algorithms require specialized hardware that ...
0
votes
0answers
82 views

On the transmit weight vector in MIMO-MRC systems

Recently, I am reading paper [1]. In this paper, the author wrote: In MIMO-MRC systems in the absence of interferers, the signal vector at the received $n_R$ antennas is given by $$\mathbf{r} = \...
0
votes
2answers
267 views

Detection of sharp peaks in an audio signal

I have an audio signal and I'm interested to detect the very sharp peaks. If I zoom, here is something that should NOT be detected (this is voice actually): NO GOOD Here is something that should be ...
2
votes
1answer
114 views

Data transmission with SNR<0dB?

I encounter a situation that it is very beneficial to limit the signal strength below noise floor. I know that the Shannon–Hartley theorem suggest that it is possible: I searched over the internet ...
0
votes
0answers
30 views

Eigenvalue based detection threhsold of sub-sampled signal

At the receiver side, I have an observed signal sampled at a rate much lower than the Nyquist rate. I would like to know how many frequency components there are in the signal. I applied the singular ...
8
votes
5answers
538 views

Estimators for improved spectral subtraction of noise

Real zero-mean Gaussian white noise, independent of a clean signal $x$ and of known variance is added to $x$ producing a noisy signal $y.$ Discrete Fourier transform (DFT) $Y$ of the noisy signal is ...
1
vote
1answer
66 views

Detection complex vectors by using correlation

I sent out a complex vector $x_i \in \{x_1,...x_n \}$ and receive a vector $y$. I use correlation $y^Hx_i$ to detect which $i$ was sent. If $y$ is corrupted by AWGN channel, the optimum rule should ...
0
votes
1answer
100 views

Multiplication and Convolution in Wireless Communications

In Wireless Communication, sometimes the received signal is expressed (in time-domain) as follows: $$r=hx+n$$ where $h$ is called a fading coefficient and sometimes it is expressed as: $$r=h*x+n$$ ...
2
votes
2answers
108 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 ...
0
votes
0answers
15 views

How to receive v-chip signals from digital TV stream

I'm trying to retrieve and decode V-chip data from my TV streams (NTSC/ATSC digital streams). Apparently these data are embedded somewhere in the stream itself, but I have no clue how they are ...
0
votes
1answer
80 views

Are there frequency detection methods that are subject to less latency than the Goertzel algorithm?

I am trying to detect oscillations in a small range around 1.5Hz as early as possible. I am currently using the Goertzel algorithm with bins 1.0Hz, 1.2Hz,..., 1.8Hz, and 2.0Hz; with block size N = 500 ...
0
votes
2answers
207 views

Homodyne and heterodyne detection

Very basic question here. I searched it on the net but cudn't get very convincing answers. Can anyone explain me Homodyne and Heterodyne detections in rf domain. Mathematically is much appreciated.
2
votes
1answer
111 views

Denoising a signal using eigendecomposition

I have a complex observable series $Y(t)$ which is the result of summing two complex r.v $X(t)$ (unobservable) and a $\epsilon(t)$ (unobservable). $$Y(t)=X(t)+\epsilon(t)$$ Assume that $X$ and $\...
1
vote
1answer
87 views

Where in the signal chain is Channel Equalization applied?

I am reading about channel equalization and I am somewhat confused on where in the signal chain channel equalization is normally applied and if it's before or after a correlator detector or matched ...
0
votes
1answer
47 views

Find identical audio signal

I have a long audio file (in wav) and a short audio file (in wav) that has been copied from the long file. Now I need to find the correct location where the short signal has been copied from. I tried ...
0
votes
1answer
93 views

How to programmatically find a sharp change in slope

First, apologies if I have the wrong group or this question is far too easy for this group. I am (as you'll see) a newbie. Please point me to another, more appropriate group OR tell me how to fix the ...
2
votes
0answers
59 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 ...
0
votes
1answer
38 views

Detecting level in a Pulse Train

Assume I have a square wave pulse train, where each high lasts for H and each low lasts for L seconds. I sample this waveform and have the sequence of numbers. Question is what should be the sampling ...
4
votes
5answers
267 views

Determine when a constant signal changes to another constant value

As a novice to digital signal processing I have a scenario that probably seems trivial but I dont know the answer to. I want to detect when a signal changes but ignore noise. 255 255 255 255 255 ...
-1
votes
1answer
29 views

Is it possible to classify biosignal data based on feature extraction through multiple linear regression model? [closed]

i have 16 channel 2 class motor imaginary right hand ,right leg data.IS it possible to classify this through multiple linear regression model based on feature extraction?can i classify 3 class data ...
3
votes
1answer
1k views

Finding a signal inside another signal

I have a 1D array of 32 bit floating point numbers representing the current draw of a radio operating over a 40 minute span. The number of elements in the array is 29 million and change. There is a ...
0
votes
1answer
189 views

Pitch detection algorithms “give up” after very little

I'm sorry if pitch detection has become a stale topic here, but I'm really interested if anyone has any advice on this topic. I'm looking for the best pitch detection algorithm for stringed ...
1
vote
1answer
43 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
votes
1answer
29 views

Signal extraction [closed]

I have a receiver which receives several signals. The different signals are summed to the receiver. How can we find a signal in this sum? I know we can use PN (pseudo-random noise) codes but I do not ...
1
vote
0answers
78 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 ...
2
votes
2answers
1k views

Preamble Detection and Frequency Offset Estimation in radio packets

I have generated a radio packet of data with a preamble header of 0x55555555 and crc32 for the data only. The entire packet was separated in even and odd streams for I and Q. The I and Q were ...