Gaussian Frequency Shift Keying (GFSK)

FSK With Preprended Gaussian Filter For More Advanced Data Transmission

GFSK is an evolution of FSK (read FSK first, then come back).

GFSK modulation is used in many modern communications technologies, i.e. Bluetooth, DECT, some WiFi.

Put short, while FSK works with simple On/Off signals similar to square waves, feeding the signal through a gaussian filter produces smoother transitions. These in turn have important electromagnetic advantages.


  • Efficiency: GFSK requires less bandwidth and increases spectral efficiency. As a direct consequence, this also conserves energy and requires less power to transmit the same information.
  • Less Interference: there is a smoother transistion between 1 and 0 states, reducing spectral splatter and adjacent channel interference.
  • Stability: Smoother frequency transitions and reduced interference in turn reduce noise and allow reliable data transmission even at high speeds.

Differences To FSK

GFSK is actually an enhanced FSK, so both modulators are technically almost identical, except for one detail: the pulses pass a gaussian filter before they enter the FSK modulator.


Please do leave comments below. I am using utteran.ce, an open-source and ad-free light-weight commenting system.

Here is how your comments are stored

Whenever you leave a comment, a new github issue is created on your behalf.

  • All comments become trackable issues in the Github Issues section, and I (and you) can follow up on them.

  • There is no third-party provider, no disrupting ads, and everything remains transparent inside github.

Github Users Yes, Spammers No

To keep spammers out and comments attributable, all you do is log in using your (free) github account and grant the permission to submit issues on your behalf.

If you don’t have a github account yet, go get yourself one - it’s free and simple.

If for any reason you do not feel comfortable with letting the commenting system submit issues for you, then visit Github Issues directly, i.e. by clicking the red button Submit Issue at the bottom of each page, and submit your issue manually. You control everything.


For chit-chat and quick questions, feel free to visit and participate in Discussions. They work much like classic forums or bulletin boards. Just keep in mind: your valued input isn’t equally well trackable there.

  Show on Github    Submit Issue

(content created Apr 17, 2024)