  A memoryless state-dependent broadcast channel (BC) is considered, where the
transmitter wishes to convey two private messages to two receivers while
simultaneously estimating the respective states via generalized feedback. The
model at hand is motivated by a joint radar and communication system where
radar and data applications share the same frequency band. For physically
degraded BCs with i.i.d. state sequences, we characterize the
capacity-distortion tradeoff region. For general BCs, we provide inner and
outer bounds on the capacitydistortion region, as well as a sufficient
condition when it is equal to the product of the capacity region and the set of
achievable distortion. Interestingly, the proposed synergetic design
significantly outperforms a conventional approach that splits the resource
either for sensing or communication.
