@inproceedings{2af00879181140ceb660dea75b83b3c7,
title = "Opportunistic Time-of-Flight Imaging Using MU-MIMO Downlink",
abstract = "Integrated sensing and communications (ISAC) has recently been identified as a crucial technology for next-generation standards because of its potential to save spectrum, cost, hardware, and other resources. A key research thrust in ISAC studies opportunistic sensing systems that utilize existing network infrastructure and communications energy to perform sensing tasks. This paper studies opportunistic time-of-flight imaging with the downlink energy transmitted by a multiuser-MIMO (MU-MIMO) cellular BS. We first recognize that the optimization of MU-MIMO beamforming is analogous to pattern optimization in MIMO radar imaging as both aim to produce spatially non-interfering transmit waveforms. Leveraging this insight, we propose a sparse-reconstruction-based image reconstruction algorithm that is expected to perform better as the number of multiplexed downlink users is increased. To support this idea, we show that the mutual coherence of the imaging sensing matrix and the reconstruction error itself decrease as the number of downlink users increases in the high signal-to-noise ratio regime. These findings reveal an alignment between communications and sensing objectives, as MU-MIMO scheduling that enables more simultaneous user data streams can induce an improved imaging waveform.",
keywords = "Communications-aided sensing, ISAC, MU-MIMO, pas-sive sensing, sparse reconstruction",
author = "Kris Li and Mishra, {Kumar Vijay} and Ashutosh Sabharwal",
note = "Publisher Copyright: {\textcopyright} 2023 IEEE.; 57th Asilomar Conference on Signals, Systems and Computers, ACSSC 2023 ; Conference date: 29-10-2023 Through 01-11-2023",
year = "2023",
doi = "10.1109/IEEECONF59524.2023.10476929",
language = "English (US)",
series = "Conference Record - Asilomar Conference on Signals, Systems and Computers",
publisher = "Institute of Electrical and Electronics Engineers Inc.",
pages = "1271--1276",
editor = "Matthews, {Michael B.}",
booktitle = "Conference Record of the 57th Asilomar Conference on Signals, Systems and Computers, ACSSC 2023",
address = "United States",
}