High rate VHF datalink

A system for very high frequency (VHF) communications mounted on an aircraft, the system comprising:

• a transceiver modulator configured to modulate signals using amplitude and phase shift keying (APSK) for amplification using a power amplifier prior to transmission across a first VHF channel of a plurality of VHF channels used to communicate between or among aircraft and one or more ground stations, the first VHF channel having a bandwidth of at least 8.33 kilo Hertz (kHz), with a data rate per Hertz (Hz) of the bandwidth greater than or equal to 3 bits per second per Hz (bps/Hz);
• an amplifier controller configured to control linearity of the power amplifier to support the data rate per Hz greater than or equal to 3 bps/Hz when the bandwidth of the first VHF channel is at least 8.33 kHz, according to at least one of a Cartesian feedback amplifier linearization, pre-distortion amplifier linearization or feedforward amplifier linearization, to mitigate nonlinear distortion associated with signals output by the power amplifier;
• a receiver configured to receive an indication of one or more time slots from the one or more ground stations, the one or more ground stations employing time division multiple access (TDMA) using the one or more time slots for communications with the aircraft;
• and
• a processor configured to select a first time slot of the one or more time slots, and to initiate the transmission according to the first time slot and a timing signal, the timing signal obtained based on a global navigation satellite system (GNSS) time signal or a clock device having time precision within 100 microseconds.

A method of a very high frequency (VHF) communications transceiver mounted on an aircraft, the method comprising:

• modulating, by an amplitude and phase shift keying (APSK) modulator, signals for transmission across a first VHF channel of a plurality of VHF channels used to communicate between or among aircraft and one or more ground stations, each of the VHF channels having a bandwidth of at least 8.33 kilo Hertz (kHz), with a data rate per Hertz (Hz) of the bandwidth greater than or equal to 3 bits per second per Hz (bps/Hz);
• amplifying, by a power amplifier, the modulated signals prior to the transmission;
• adjusting, by a linearity controller, linearity of the power amplifier according to at least one of a Cartesian feedback amplifier linearization, pre-distortion amplifier linearization or feedforward amplifier linearization to mitigate nonlinear distortion associated with signals output by the power amplifier;
• receiving an indication of one or more time slots from the one or more ground stations, the one or more ground stations employing time division multiple access (TDMA) using the one or more time slots for communications with the aircraft;
• and
• selecting, by a processor, a first time slot of the one or more time slots, and to initiate the transmission according to the first time slot and a timing signal, the timing signal obtained based on a global navigation satellite system (GNSS) time signal or a clock device having time precision within 100 microseconds.