STAR-RIS Assisted Massive MIMO ISAC System with Partial Zero-Forcing Precoding

We consider a simultaneously transmitting and reflecting reconfigurable intelligent surface (STAR-RIS) assisted massive multiple-input multiple-output (mMIMO) integrated sensing and communication (ISAC) system, accounting for both direct and indirect paths to serve the communication users. We practically model the system by employing hybrid partial zero forcing (PZF) precoding to achieve a balance between system performance and computational complexity. We derive the closedform expressions for the achievable sum-rate and mean-to-average sidelobe ratio (MASR) as the communication and sensing metric for the proposed system, respectively. We numerically analyze the impact of STAR-RIS on the trade-off between sensing and communication performance. Additionally, we investigate the performance of PZF precoding for the proposed system.