Full-duplex ISAC with uplink users at monostatic transceivers

Develop methods to integrate uplink users into full-duplex monostatic joint sensing and communication at a base station by designing precoders/combiners and receiver digital processing that separate target reflections from uplink signals, thereby enabling full-duplex communications without compromising sensing or suffering self-interference.

Background

The paper presents designs for monostatic sensing with full-duplex (FD) transceivers focusing mainly on downlink communication and sensing.

It notes that extending to full-duplex communications by integrating uplink users introduces challenging receiver design requirements to separate target echoes from uplink transmissions in the presence of self-interference.

Solving this would significantly improve spectrum efficiency and enable practical FD ISAC operation.

References

One of the most important challenges is to integrate UL users to enable FD communication which would significantly improve the spectrum efficiency of the overall system. This is an open problem that needs to be solved with the precoder/combiner design and the digital processing at the RX.

— The Integrated Sensing and Communication Revolution for 6G: Vision, Techniques, and Applications  (2405.01816 - González-Prelcic et al., 2024) in Triple-function precoding/combining in full duplex transceivers, Precoding/combining for initial access (Section: Technologies for joint monostatic sensing and communication)

Returning to the center of the trefoil (Fig.~\ref{fig:trefoil}), Integrated Sensing and Communication (ISAC) is the joint-services result that closes the function-level argument, but no HAPS demonstrator has yet flown a shared-aperture, shared-waveform ISAC payload.

— HAPS through the Lens of Satellites and UAVs: A Function-Level Perspective on the Emerging High Altitude Economy  (2608.16828 - Ahmad et al., 17 Aug 2026) in Section 9.8, “Tier 8: ISAC at Altitude”