Gaussian Frequency Shift Keying

/ˈɡaʊsiən ɛf ɛs keɪ/

noun — "smooth frequency shifts for cleaner, narrower signals."

GFSK (Gaussian Frequency Shift Keying) is a digital modulation scheme derived from FSK in which the transitions between frequencies are filtered with a Gaussian-shaped pulse to reduce bandwidth and minimize spectral splatter. Each frequency represents a binary state, but the Gaussian filter smooths abrupt frequency changes, producing a more spectrally compact signal suitable for crowded or interference-sensitive channels.

Binary Frequency Shift Keying

/biː ɛf ɛs keɪ/

noun — "two tones, one bit, zero ambiguity."

BFSK (Binary Frequency Shift Keying) is a digital modulation technique where data is transmitted by switching a carrier signal between exactly two distinct frequencies. Each frequency represents one binary state: typically one tone encodes binary 0, and the other encodes binary 1. It is the simplest and most fundamental form of FSK.

Multiple Frequency Shift Keying

/ɛm ɛf ɛs keɪ/

noun — "more frequencies, more symbols, less confusion per hertz."

MFSK (Multiple Frequency Shift Keying) is a digital modulation scheme in which data is transmitted by shifting a carrier signal among more than two discrete frequencies. Each distinct frequency represents a unique symbol that encodes multiple bits of information, making MFSK a generalization of FSK, where only two frequencies are used.

CK

/siːˈkeɪ/

n. "Differential DDR clock pair CK/CK# synchronizing command/address at every rising edge unlike source-synchronous DQS."

DQS

/ˌdiː kjuː ˈɛs/

n. "DDR memory strobe signal capturing DQ data on both clock edges via source-synchronous timing unlike common system CLK."