Learn SDR 13: Quadrature Phase-Shift Keying (QPSK)
Channel: HarveyMuddPhysicsElectronicsLab
Date: 13/10/2022

Learn SDR with Professor Jason Gallicchio at Harvey Mudd College
Lesson 13: QPSK naive with no pulse shaping (naive: 100x repeat with no pulse shaping)

Chunks to Symbols

You get 2x as much data in the same bandwidth, because the spectrum is no longer symmetric.

The redundancy did buy you some tolerance for noise, so it makes sense for GPS, for example, to use PSK.

Constellation Object

Constellation Decoder only makes sense if you have the phase and timing correct. It might work for ASK, but not worth it.

Must know that it secretly and automatically normalized so mean(abs(symbols))==1

Mention 8-PSK, QAM and other constellations

Differential signaling to avoid phase ambiguity

https://gallicchio.github.io/learnSDR/lesson13.html

All GNURadio flowgraphs are at:
https://github.com/gallicchio/learnSDR

--- Learn SDR with Professor Jason Gallicchio