COFDMTV

COFDMTV

Mode	SSB,FM,AM
Modulation	COFDM,8-PSK,QPSK
ACF	—
Emission Designator	—
Bandwidth	1.6 kHz,2.5 kHz,2.7 kHz,3.2 kHz,2.25 kHz,2.4 kHz
Location
Short Description	COFDMTV is an easy-to-use picture transmission mode based on Coded Orthogonal Frequency-Division Multiplexing (COFDM).
I/Q Raw Recording	—
Audio Sample

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

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

Samples

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 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 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 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 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 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 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 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 24 seconds long

Video Example

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

Decoding Software

• Shreadpix (Modulator)
• Assempix (De-Modulator)

Additional Links

• COFDM Info