Droitwich also broadcasts a low bit-rate data channel, using narrow-shift phase-shift keying of the carrier, for Radio Teleswitch Services.
22.
These audio tones, then, SSB transmitter to produce the final audio-frequency shift keying ( AFSK ) radio frequency signal.
23.
Since this scheme depends on the difference between successive phases, it is termed differential phase-shift keying ( DPSK ).
24.
Radioteletype, fax, digital, slow-scan television and other systems use forms of frequency-shift keying or audio subcarriers on a shortwave carrier.
25.
It transmits using 1200 bit / s binary phase shift keying ( BPSK ), a very robust binary modulation scheme.
26.
The voice was keyed to two 16-inch vinyl phonograph records that contained a Frequency Shift Keying ( FSK ) audio tone.
27.
The control channels use signalling at 1, 200 bits per second with fast frequency shift keying ( FFSK ) subcarrier modulation.
28.
Instead of the traditional frequency-shift keying, the information is transmitted by patterns of polarity-reversals ( sometimes called 180-degree phase shifts ).
29.
Since this scheme depends on the difference between successive phases, it is termed "'differential phase-shift keying ( DPSK ) " '.
30.
This modem operates with a symbol rate of 75 Baud, using Coherent Quadrature Phase-Shift Keying ( QPSK ) with seven sub-carriers.
