Opportunistic Time-of-Flight Imaging Using MU-MIMO Downlink

Kris Li, Kumar Vijay Mishra, Ashutosh Sabharwal

Research output: Chapter in Book/Report/Conference proceedingConference contribution

1 Scopus citations

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.

Original languageEnglish (US)
Title of host publicationConference Record of the 57th Asilomar Conference on Signals, Systems and Computers, ACSSC 2023
EditorsMichael B. Matthews
PublisherInstitute of Electrical and Electronics Engineers Inc.
Pages1271-1276
Number of pages6
ISBN (Electronic)9798350325744
DOIs
StatePublished - 2023
Event57th Asilomar Conference on Signals, Systems and Computers, ACSSC 2023 - Pacific Grove, United States
Duration: Oct 29 2023Nov 1 2023

Publication series

NameConference Record - Asilomar Conference on Signals, Systems and Computers
ISSN (Print)1058-6393

Conference

Conference57th Asilomar Conference on Signals, Systems and Computers, ACSSC 2023
Country/TerritoryUnited States
CityPacific Grove
Period10/29/2311/1/23

Keywords

  • Communications-aided sensing
  • ISAC
  • MU-MIMO
  • pas-sive sensing
  • sparse reconstruction

ASJC Scopus subject areas

  • Signal Processing
  • Computer Networks and Communications

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