  Integrated sensing and communication (ISAC) is a promising technology to
fully utilize the precious spectrum and hardware in wireless systems, which has
attracted significant attentions recently. This paper studies ISAC for the
important and challenging monostatic setup, where one single ISAC node wishes
to simultaneously sense a radar target while communicating with a communication
receiver. Different from most existing schemes that rely on either
radar-centric half-duplex (HD) pulsed transmission with information embedding
that suffers from extremely low communication rate, or communication-centric
waveform that suffers from degraded sensing performance, we propose a novel
full-duplex (FD) ISAC scheme that utilizes the waiting time of conventional
pulsed radars to transmit dedicated communication signals. Compared to
radar-centric pulsed waveform with information embedding, the proposed design
can drastically increase the communication rate, and also mitigate the sensing
eclipsing and near-target blind range issues, as long as the self-interference
(SI) is effectively suppressed. On the other hand, compared to
communication-centric ISAC waveform, the proposed design has better
auto-correlation property as it preserves the classic radar waveform for
sensing. Performance analysis is developed by taking into account the residual
SI, in terms of the probability of detection and ambiguity function for
sensing, as well as the spectrum efficiency for communication. Numerical
results are provided to show the significant performance gain of our proposed
design over benchmark schemes.
