Distortion-Aware Transmit Precoding for Integrated Sensing and Communication Systems

In this letter, we focus on precoding in integrated sensing and communication (ISAC) systems with residual hardware impairments. Specifically, we design transmit precoders at a dual-function radar communication base station (DFBS) to maximize the useful target illumination power (TIP) while guaranteeing the desired signal-to-interference-distortion-plus-noise ratio for the users and limiting the TIP arising from distortions. The underlying problem is non-convex. We propose convex relaxations to transform the precoder design problem to a semidefinite transmit covariance design problem that can be solved by off-the-shelf solvers. We also present a method to extract the required transmit precoders from the corresponding covariances. Through numerical simulations, we demonstrate that the proposed distortion-aware precoding implemented at the DFBS outperforms the case where the distortion statistics are not considered while precoding at the DFBS.