# COFDMTV

The modes below use a 2/3-rate shortened systematic polar code and are differentially modulated:

using SPC(64800, 43072):

mode 6: 8PSK8-Phase Phase-Shift Keying (3 bits per symbol), 2700 HzHertz (Hz), unit of frequency, defined as one cycle per second (1 Hz). BW and about 10 seconds long

mode 7: 8PSK8-Phase Phase-Shift Keying (3 bits per symbol), 2500 HzHertz (Hz), unit of frequency, defined as one cycle per second (1 Hz). BW and about 11 seconds long

mode 8: QPSKQuadrature Phase-Shift Keying (2 bits per symbol), 2500 HzHertz (Hz), unit of frequency, defined as one cycle per second (1 Hz). BW and about 16 seconds long

mode 9: QPSKQuadrature Phase-Shift Keying (2 bits per symbol), 2250 HzHertz (Hz), unit of frequency, defined as one cycle per second (1 Hz). BW and about 18 seconds long

using SPC(64512, 43072):

mode 10: 8PSK8-Phase Phase-Shift Keying (3 bits per symbol), 3200 HzHertz (Hz), unit of frequency, defined as one cycle per second (1 Hz). BW and about 9 seconds long

mode 11: 8PSK8-Phase Phase-Shift Keying (3 bits per symbol), 2400 HzHertz (Hz), unit of frequency, defined as one cycle per second (1 Hz). BW and about 11 seconds long

mode 12: QPSKQuadrature Phase-Shift Keying (2 bits per symbol), 2400 HzHertz (Hz), unit of frequency, defined as one cycle per second (1 Hz). BW and about 16 seconds long

mode 13: QPSKQuadrature Phase-Shift Keying (2 bits per symbol), 1600 HzHertz (Hz), unit of frequency, defined as one cycle per second (1 Hz). BW and about 24 seconds long

The modes allow for a payload of up to 5380 bytes. COFDMTV is based on COFDMCoded Orthogonal Frequency-Division Multiplexing (coded orthogonal frequency-division multiplexing) technology:

- 160 msmilliseconds (.001 of a second) long OFDMOrthogonal Frequency-Division Multiplexing symbols

- 6.25 HzHertz (Hz), unit of frequency, defined as one cycle per second (1 Hz). per sub-carrier

- 1⁄8 guard interval

- Differentially encoded PSKPhase-Shift Keying (phase-shift keying) modulation

- Systematic polar codes for forward error correction

## Frequencies[edit]

This mode is often used on UHFCB, PMR446, and FRS.

## Video Example[edit]

- Receiving COFDMTV encoded picture from a shortwave radio using AM modulation
- Receiving COFDMTV encoded picture from PMR handheld radio