Patent ID: 8599956

Claim:
A system for compensating for a Doppler frequency shift in communications between a plurality of mobile nodes and a fixed node, comprising: a mobile transmission source housed within an aircraft, the mobile transmission source being configured to repeat communications between the a plurality of mobile nodes and the fixed node; a GPS unit for determining a location associated with the mobile transmission source; an INS unit for determining a heading and a speed associated with the mobile transmission source; a Doppler frequency shift estimation unit located external to the mobile transmission source, the Doppler frequency shift estimation unit being configured to estimate the Doppler frequency shift experienced in a communication signal between the mobile transmission source and the fixed node, wherein the Doppler frequency shift is estimated based on the location, the heading, and the speed associated with the mobile transmission source and a location of the fixed node, wherein the location of the fixed node is determined by at least one of a microprocessor, a DSP, and an ASIC configured to detect a broadcast control channel transmitted by the fixed node including an identification code and further configured to cross-correlate the identification code with entries stored in a databased including a listing of a plurality of locations corresponding to a plurality of fixed nodes; and a frequency shift unit located external to the mobile transmission source, the frequency shift unit being configured to shift a frequency of the communication signal in accordance with the estimated Doppler frequency shift, wherein the frequency shift unit comprises a digital synthesizer configured to produce a shifting frequency corresponding to the estimated Doppler frequency shift and RF mixer configured to mix the shifting frequency with the communication signal.