Multistatic Sensing for Target Localization in ISAC Systems with Dynamic and Unknown-Location Transmitters

Abstract

Current research on integrated sensing and commu nication (ISAC) primarily examines the use of communication waveforms to derive radar parameters, but there is a significant gap in methods for accurately locating targets using these parameters. Therefore, this paper explores target localization solutions within an ISAC system under two scenarios. First, we investigate tracking a moving target using multistatic sensing with dynamic transmitters (TXs). Unlike existing two-step weighted least square (2SWLS) methods, which rely on the bistatic range (BR) and bistatic range rate (BRR) measurements, our method incorporates an additional direction of arrival (DOA) measurement. This innovation reduces the minimum number of required transmitter receiver (TX-RX) pairs, needing only one TX-RX pair for position estimation and two TX-RX pairs for velocity estimation, thereby improving system efficiency and accuracy. In the second scenario, we address the challenge of unknown-location TXs. We pioneer a novel method that simultaneously tracks the moving target and determines the locations of these unknown-location TXs. This approach operates effectively with only three TX-RX pairs, overcoming the significant obstacle of operating without prior knowledge of TX positions. Simulations validate the effectiveness of our proposed methods. For the first scenario, our method demonstrates superior performance compared to existing 2SWLS methods. For the second scenario, our method successfully navigates the complexity of unknown-location TXs, achieving reliable target tracking and TX localization. As a result, this paper fills the gap in current ISAC studies by providing detailed methods for accurately locating a target using radar parameters obtained from an ISAC receiver.