  In this paper we present a method that prevents an unauthorized receiver
(URx) from correctly estimating the Doppler shift present in an orthogonal
frequency division multiplexing (OFDM) wireless signal. To prevent this
estimation we propose to insert an artificial frequency variation in the
transmitted signal that mimics a transmitter (Tx) movement with a spoofed/fake
speed. This spoofed Doppler shift does not affect data demodulation since it
can be compensated at the legitimate receiver (LRx). We evaluate our method for
its efficacy through simulations and we show that it offers a reliable way to
protect one key element of the privacy of a wireless source, namely the speed
of the transmitter.
