Hardware-Impaired Massive MIMO ISAC System Under the Finite-Blocklength Regime

Abstract

This paper investigates a hardware-impaired, ultrareliable low-latency communication (URLLC)-aware massive multiple-input multiple-output (MIMO) integrated sensing and communication (ISAC) system under the finite-blocklength regime. We propose a partial zero-forcing structured transmit beamforming (PZF-STB) scheme that enables the reuse of communication symbols for sensing while leveraging the complementary benefits of zero-forcing (ZF) and maximum ratio (MR) precoding. We derive closed-form expressions for the URLLC rate and the sensing signal-to-clutter-plus-noise ratio (SCNR) under hardware impairments (HWIs), and analyze matched filtering (MF) and minimum variance distortionless response (MVDR) combining schemes for sensing. Numerical results demonstrate that HWIs significantly deteriorate both communication and sensing performance, leading to a substantial reduction in URLLC rates, network availability, and sensing SCNR. PZF-STB achieves a favorable balance between interference suppression and beamforming gain. MVDR combining achieves a higher minimum SCNR than MF in a clutter environment.