SYSTEM AND METHODS FOR CLOSED LOOP DOPPLER TRACKING IN INTER-SATELLITE LINKS

An apparatus can include transceiver circuitry to receive an input signal from a target apparatus. The apparatus can further include a processing circuitry to determine position information of a source object and a target object. Based on the position information, the processing circuitry can calculate a relative velocity and determine a Doppler shift or carrier frequency offset in the input signal based on the relative velocity. The processing circuitry can adjust a local oscillator frequency based on a Doppler measured using the position information in an initial link acquisition phase. The processing circuitry can track the Doppler continuously over a range of tens of gigahertz accounting for Doppler phase ambiguities, and correct for a tracked Doppler shift by partially adjusting a local oscillator frequency and by correcting a residual Doppler shift digitally.