Questions tagged [fsk]

Frequency Shift Keying - A digital transmission technique in which a "1" is represented by one frequency and a "0" by another. It is the digital equivalent of FM.

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What is 2-FSK modulation?

In the documentation for a radio chip, I keep seeing the term 2-FSK, which seems to be a modulation scheme. My understanding is that in FSK, data is encoded by emitting a carrier wave on a number of different frequencies. Is this right? How does…
Toby Jaffey
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Why do we need orthogonality for FSK carriers?

I keep on coming across a requirement for FSK carrier separation, \$1/T\$ for non-coherent detection and \$1/2T\$ for coherent detection, where \$T\$ is bit period. I understand where this comes from in the context of an optimal quadrature receiver,…
snEE
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Best method for sending data over a mono audio channel

I'm looking for a way to send binary data over an audio channel on a video/audio transmitter. This will be an add-on feature to my product because it already has an audio interface. I'm hoping to be able to reach about 1 kbit/s data rate at a…
Thomas O
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Software based Caller ID project- Problem with getting caller ID signal

Nowadays, I am trying to make a Caller ID project without using Caller ID ICs. Firstly, I have done a lot of research in Google to get information of phone lines and their electrical properties. I have found and done: In my country Caller ID data…
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FSK Modulation in Python

I am currently writing a script that uses I/Q data to do FSK modulation. My question is about the FFT plot. I expected to have a peak at 1Hz and 2Hz which are the frequencies that represent binary 0 and 1, however I have peaks at 2 and 4Hz. I…
PrematureCorn
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FSK demodulation using DSP

Especifically talking, I need to demodulate a low frequency FSK signal( betwen 120 and 140 kHz ). I already have a circuit of antenna that receive the signal and I already can sample it, but I still have a doubt of how could be the best way, faster…
Daniel
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Identifying 40Hz frequency shift

I have a signal that is at 4 kHz. This signal shifts by 40 Hz depending on some user input. I like to detect this change in software as fast as I can. What should be the ADC frequency I should use? I currently plan to sample at 40 kHz and use a…
TGG
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distortion on transition of bits in FSK

I have a question regarding the distortion I see at the transition of bit '0' and '1' in an FSK, I have the receiver connected to a sensing circuit at two frequencies, because my input is current limited at the sensing frequencies I would like the…
user3602697
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Receiver understanding FSK bandwidth

I have a small doubt in a one way wireless communication. If I am using a receiver chip to demodulate an FSK signal. How does the receiver understands, which frequency to listen to? For example, I have a central frequency of 2.4 GHz and my FSK…
Floyd
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Simple way to decoding FSK

I'm trying to build simple fsk transmitter and receiver, the transmitter is just an FPGA with a wire, the logic is quite simple, I mix (with a XOR) the transmission frequency with a lower frequency, thats create some distortions which can be picked…
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ramp-up "guard" time (data receiver)

I have looked at multiple datasheets of multiple radio modules including one I'm using (HM-TRP) and none of them specify a ramp-up or a ramp-down time. According to research, this is known as the guard time. Through my own experimentation with data…
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FSK constellation and eye diagrams

why do constellation diagram and eye diagram not show any useful output for FSK? I have tried to find that on Simulink Mathwork, but the progress was negetive.
Ah Ali
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Problem in FSK demodulation

I have a FSK modulated signal of binary data. This I am trying to recover using PLL. The mark and space frequencies are in the range of 1.5MHz to 7MHz. I am struggling because, the PLL output is not stable, in the sense that the signal is varying…
cppiscute
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Coherent and non-coherent detection

Let's say I am simulating something as simple as BFSK. It has two symbols, one entirely on the real plane, and one entirely on the complex plane for representing let's say zero. That is how the constellation of BFSK looks like. Now let's say we…
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How high should I make an FSK modulation index value?

After consulting with the radio manufacturer about a setup for my FSK radio module (HM-TRP), they have suggested I program it with the following values when setting up the module for 115kbps: Receive bandwidth: about 120Khz Frequency Deviation:…
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