Signal Processing Stack Exchange
Signal Processing Stack Exchange

Questions tagged [signal-detection]

441 questions
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This is about signal processing in the first radar

I read in a book that the first radar was a CW one that was used to detect ships. Since it was CW, did it use Doppler to detect the moving ships? What was the signal processing used in it? Is there any reference to this information?
Seetha Rama Raju Sanapala
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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 cannot be done automatically. When scanning for radio…
Malvineous
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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 do this if expected frequency of the useful signal…
Mykola Pavlov
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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 rate is low (1.25s). We have multiple observations…
jdv
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Decoding of binary signal from a temperature sensor

I have the following signal from a temperature sensor (broadcasts on 433.92 MHz, apparently as ASK). I cannot for the life of me extract the temperature data. I've tried reading off the bits in so many different ways (mostly by looking at the pulse…
Nick Lang
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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 radio stations that use the same bandwidth of 5…
Calvin
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A question about GLRT

I did an experiment of detecting an unknown DC level in AWGN with unknown variance according to Steven M Kay's Detection Theory. For one set of samples $x(i)=a+n(i)$, the GLRT is $T_x=N\log(\hat{\sigma}_{x0}^2/\hat{\sigma}_{x1}^2)$ where…
c1119
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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. Can anyone suggest me ways to calculate the…
North
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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 this width). This is prescribed at the left end…
Millemila
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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 show. Question In many technical applications,…
M529
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Far field spherical waves plane waves

All em radiation propagates spherically and at a far off place a small enough distance, when observed appears like a plane like our experience on the earth. So I tend to think that whether a wave on an aperture can be considered plane or not…
Seetha Rama Raju Sanapala
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How whip antenna even work if they don't have two terminals?

I understand antenna should have two terminals to emit radio waves like this: But in whip antenna it has only one pointy terminal, how does it work?
J Boya
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m-ary antipodal signaling

I know that the error probability for binary antipodal signaling is $Q(\sqrt{2E_b/N_0})$ with $Q$ the tail function. I was wondering if when used in a m-ary scheme how the probability error would change. What I mean by that would be a signaling…
james
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If I can make a call to another city, why does wifi only reach 50 meters?

What makes it possible for me to communicate with someone in another city when my phone can only reach the modem / wifi networks that are within 50 meters? The signal may be sent between multiple destinations before reaching the final destination /…
user48054
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Proper HW circuit to decode PWM signal using Arduino Mini

I want to properly connect a Radio Control Receiver signal to a Arduino Pro Mini, Pin 11 so I can detect the 1 ms to 2 ms PWM signal. I calculate a value of 220 ohms will limit the circuit current to 22mA. The Arduino strongly suggests using 20mA…
Garry48
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