Learn SDR 12: Phase-Shift Keying (PSK)

Learn SDR with Professor Jason Gallicchio at Harvey Mudd College
Lesson 12 Binary Phase Shift Keying (BPSK)
(naive rectangular pulses: 100x repeat with no pulse shaping)
No pulse shaping -- just slow +1,-1 times the carrier.
[0,1,0,1,0,0,0,1,1,0,0,0,1,1,1,1]
Chunks to Symbols
Really need to fine tune frequency.
Ambiguity: Even when tuned, how do you ever tell apart +1 and -1?
Relevant for communications, radar, and GPS -- this is the right signal to correlate against.
Costas Loop? No.
HW: Square the incoming signal (multiply by itself)--you remove the modulation and get a tone that's at twice the frequency offset.
HW: Differential Encoder and Differential Decoder
gallicchio.git...
All GNURadio flowgraphs are at:
github.com/gal...
--- Learn SDR with Professor Jason Gallicchio

[@sleepymarauder4178]

Why use a Cosine wave to multiply it with a Complex Exponential?