Discrete MultiTone

/diː ɛm ˈtiː/

noun — "splitting a signal into multiple channels for cleaner data."

DMT (Discrete MultiTone) is a modulation technique that divides a communication channel into multiple orthogonal subcarriers, each carrying a separate data stream. It is widely used in digital subscriber line (DSL) technologies, such as ADSL, to maximize bandwidth efficiency and reduce interference. By transmitting data simultaneously across multiple tones, DMT mitigates the effects of channel noise, crosstalk, and frequency-selective fading.

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.

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