  This paper investigates the performance tradeoff for a multi-antenna
integrated sensing and communication (ISAC) system with simultaneous
information multicasting and multi-target sensing, in which a multi-antenna
base station (BS) sends the common information messages to a set of
single-antenna communication users (CUs) and estimates the parameters of
multiple sensing targets based on the echo signals concurrently. We consider
two target sensing scenarios without and with prior target knowledge at the BS,
in which the BS is interested in estimating the complete multi-target response
matrix and the target reflection coefficients/angles, respectively. First, we
consider the capacity-achieving transmission and characterize the fundamental
tradeoff between the achievable rate and the multi-target estimation
Cram\'er-Rao bound (CRB) accordingly.
