  A dual-robust design of beamforming is investigated in an integrated sensing
and communication (ISAC) system.Existing research on robust ISAC waveform
design, while proposing solutions to imperfect channel state information (CSI),
generally depends on prior knowledge of the target's approximate location to
design waveforms. This approach, however, limits the precision in sensing the
target's exact location. In this paper, considering both CSI imperfection and
target location uncertainty, a novel framework of joint robust optimization is
proposed by maximizing the weighted sum of worst-case data rate and beampattern
gain. To address this challenging problem, we propose an efficient two-layer
iteration algorithm based on S-Procedure and convex hull. Finally, numerical
results verify the effectiveness and performance improvement of our dual-robust
algorithm, as well as the trade-off between communication and sensing
performance.
