  A novel multistatic multiple-input multiple-output (MIMO) integrated sensing
and communication (ISAC) system in cellular networks is proposed. It can make
use of widespread base stations (BSs) to perform cooperative sensing in wide
area. This system is important since the deployment of sensing function can be
achieved based on the existing mobile communication networks at a low cost. In
this system, orthogonal frequency division multiplexing (OFDM) signals
transmitted from the central BS are received and processed by each of the
neighboring BSs to estimate sensing object parameters. A joint data processing
method is then introduced to derive the closed-form solution of objects
position and velocity. Numerical simulation shows that the proposed multistatic
system can improve the position and velocity estimation accuracy compared with
monostatic and bistatic system, demonstrating the effectiveness and promise of
implementing ISAC in the upcoming fifth generation advanced (5G-A) and sixth
generation (6G) mobile networks.
