This paper studies a multi-antenna networked integrated sensing and
communications (ISAC) system, in which a set of multi-antenna base stations
(BSs) employ the coordinated transmit beamforming to serve multiple
single-antenna communication users (CUs) and perform joint target detection by
exploiting the reflected signals simultaneously. To facilitate target sensing,
the BSs transmit dedicated sensing signals combined with their information
signals. Accordingly, we consider two types of CU receivers with and without
the capability of canceling the interference from the dedicated sensing
signals, respectively. In addition, we investigate two scenarios with and
without time synchronization among the BSs. For the scenario with
synchronization, the BSs can exploit the target-reflected signals over both the
direct links (BS-to-target-to-originated BS links) and the cross-links
(BS-to-target-to-other BSs links) for joint detection, while in the
unsynchronized scenario, the BSs can only utilize the target-reflected signals
over the direct links. For each scenario under different types of CU receivers,
we optimize the coordinated transmit beamforming at the BSs to maximize the
minimum detection probability over a particular targeted area, while
guaranteeing the required minimum signal-to-interference-plus-noise ratio
(SINR) constraints at the CUs. These SINR-constrained detection probability
maximization problems are recast as non-convex quadratically constrained
quadratic programs (QCQPs), which are then optimally solved via the
semi-definite relaxation (SDR) technique.Comment: arXiv admin note: text overlap with arXiv:2211.0108