  Frequency-hopping (FH) joint radar-communications (JRC) can offer excellent
security for integrated sensing and communication systems. However, existing
JRC schemes mainly embed information using only the sub-pulse frequencies and
hence the data rate is limited. In this paper, we propose to use both sub-pulse
frequencies and durations for information modulation, leading to higher
communication data rates. For information demodulation, we propose a novel
scheme by using the time-frequency analysis (TFA) technique and a "you only
look once" (YOLO)-based detection system. As such, our system does not require
channel estimation, simplifying the transmission signal frame design.
Simulation results demonstrate the effectiveness of our scheme, and show that
it is robust against the Doppler shift and timing offset between the
transceiver and the communication receiver.
