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Write-up - Digital Signaling Fundamentals

KH6CP Craig Paul
 

I've written about digital signaling: including Frequency Shift Keying (including RTTY), Phase Shift Keying (PSK31 for example), Quadrature Phase Shift Keying (QPSK), and Quadrature Amplitude Modulation (QAM).

I write about how weak signal modes (FT8 and related modes, FLDIGI's "Micro Modes",
and Multipsk's Lentus) work.

I cover Orthogonal Frequency Division Multiplexing (OFDM) found in MT63, 8PSK multicarrier, and VARA.
This includes screenshots from an active high-speed VARA FM session showing how to interpret the
training sequence, constellation, and speed negotiation during the transmission.

I briefly cover Forward Error Correction (FEC).
FLDIGI has modes that provide FEC.

Digital signaling fundamentals - https://docs.google.com/document/d/e/2PACX-1vTOhfNAkQqNs6nO2HI1kuTtvBd7sWFD9xJtYQBWOp1DmI5X87CIPa1yg3Jr-LhkzXpUV1CPt2deQr6S/pub

Let me know what you think!

Craig/KH6CP
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