Blind Doppler Tracking from OFDM Signals Transmitted by Broadband LEO Satellites

An algorithm for blind Doppler frequency estimation from orthogonal frequency division multiplexing (OFDM) signals transmitted by low Earth orbit (LEO) satellites is developed. A method for resolving the ambiguity in the Doppler estimate is also discussed. Two sets of experimental results are presented. The first demonstrates blind Doppler estimation from terrestrial fifth-generation (5G) signals on a mobile ground vehicle, achieving 14.5 Hz Doppler root mean-squared error (RMSE). The second demonstrates an unmanned aerial vehicle navigating using the proposed approach with emulated 5G signals from two Orbcomm LEO satellites for a period of 2 minutes, achieving 15.16 m position RMSE.