  Joint RADAR communication (JRC) systems that use orthogonal frequency
division multiplexing (OFDM) can be compromised by an adversary that
re-produces the received OFDM signal creating thus false RADAR targets. This
paper presents a set of algorithms that can be deployed at the JRC system and
can detect the presence of false targets. The presence of a false target is
detected depending on whether there is residual carrier frequency offset (CFO)
beyond Doppler in the received signal, with a Generalized Likelihood Ratio Test
(GLRT). To evaluate the performance of our approach we measure the detection
probability versus the false alarm rate through simulation for different system
configurations of an IEEE 802.11-based JRC system.
