FSK or Frequency-Shift Keying is a frequency modulation scheme in which digital information is transmitted through discrete frequency changes of carrier waves.

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Gray code and M-FSK

Does using a gray code mapping with M-FSK improve the BER performance vs no mapping? I know it helps QAM, and it makes intuitive sense. Doesn't seem as clear cut for M-FSK.
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BFSK modulation what signal the transmitter actually sends?

I am trying to understand how modulation with carriers works(transmission part). I will express my question in terms of BFSK for simplicity. Let us condiser BFSK modulation with symbols {1,2}. Then ...
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*FSK decoding primitives

I've been trying to write an MFSK demodulator, although what I'm really asking probably applies to generalized continuous-phase FSK as well. Right now, I've got a very simple technique that assumes ...
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BFSK software demodulation with zero crossing rate - sync problems

I try to decode my bits which are seperated by 100 Hz: '0'=13KHz, '1'=13.1KHz. Now, I'm just trying to send 8 bits in a 15msec ...
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Detecting FSK near real time with c#

I try to detect some FSK signals made by audio in near real time. I know that I will get some latency. In the start I try to detect some tones of 10Khz in a duration of 75ms. That is achieved by a ...
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Bandwidth of a trimmed sinus wave

I generate a sinus which duration is 15ms and frequeuncy of 13KHz. Is its bandwidth is (1/15ms) ? Or in other words, BW = 66.6Hz? I ask that because I have two freqs in my system: 13K & 13.1K. I ...
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Changes of phase in high frequency makes the speaker “clicks”

I modulate some data over sound in a 17.7Khz and 17.8Khz. It works like an FSK with a pulse duration of 0.015sec. When playing a string the speaker gives a very strange noise that it seems to be the ...
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Detection of an FSK Signal

This is probably as basic a question as it gets, but still the answer eludes me. I have a function from a library that I can use to both modulate, and demodulate an FSK encoded piece of data. For the ...
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SigLib FSk Function: SDA_FskModulate

I would like to implement the example code from SigLib's example "fsk.c". The defines are below #define SAMPLE_LENGTH ((SLArrayIndex_t)512) #define NUMBER_OF_LOOPS ...
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Detect FSK high/low bits in presence of noise with only simple processing

I'm currently in the process of writing DSP code, based on the amazing RTLSDR project, and using this as a vehicle to teach myself the basics of DSP (I have an extensive background in software ...
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Spectral effects of multiplying a signal by itself?

This has to do with creating the synchronization circuit for MSK in a DSP as described in "Minimum Shift Keying" by Subbarayan Pasupathy published in IEEE Communications Magazine. At the beginning of ...
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Noise from CPFSK

I am programmatically generating a CPFSK encoding, and between shifting from two frequencies, there is extra noise generated by my speaker. For instance, going from 18375hz to 18900hz, there is extra ...
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Orthogonality of FSK modulation for non-coherent detection

For an FSK modulation with coherent detection, in order to ensure orthogonality, the frequency separation between symbols is $ \Delta f=f_2 - f_1 =1/2T$. However, in case of non-coherent demodulation, ...
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Finding BER, using FSK at GSM network

I would like to ask, cuz I don't know much from that, how we can find the BER at a GSM network (uplink & downlink separately of course), while we are using FSK modulation? I mean the equations ...
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How should I modulate a $16$ bit input using FSK?

I need to graph a $16$ bits binary sequence, assuming that it'll be a FM analog signal I need to apply FSK to it. So, I think I should use the formula $A \cos(2\pi f_1 t)$ for binary $1$'s $A ...
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Why is Frequency Shift Keying more immune to noise than ASK?

Is it because noise manifests itself in the transmitted signal's amplitude?
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PC-to-PC data communication over Sound FSK / PSK / DSSS

For fun and work I've to implement a java based application that can Encode text or data to sound and transmit using PC's speaker and on the receiving side is a microphone with decoder software. I ...
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Demodulation of noisy AFSK signal

I'm trying to implement a software audio modem with fsk to transmit and receive short digital data between two devices (ex a PC and an iPhone) so I'm simulating simple cases study using Scilab/Matlab. ...
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AFSK clock recovery in noise

What algorithms are available for optimizing estimated bit clock recovery of an audio FSK modulated signal over an extremely low S/N ratio channel? (e.g. barely audible due to high ambient noise and ...
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How to demodulate an AFSK signal in software

I am trying to transmit binary data from one device to another over an audio channel (speaker/mic). I use AFSK (Audio Frequency Shift Keying) as in Packet Radio, with $1200 \text{ Baud}$ and two ...
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Spectrum of FSK signal

I have implemented a simple V.23-like FSK modem in C here. The peculiarity of the chosen modulation is such that 0's and 1's are sent as tones of two different frequencies (2100 Hz and 1300 Hz ...