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Graph-Based Multi-Bounce Modeling and Channel Parameter Estimation for Indoor Sensing

Liu, Yuan ; Wu, Linlong ; Cai, Xuesong LU and Shankar, M. R.Bhavani (2025) In IEEE Transactions on Wireless Communications 24(5). p.4219-4234
Abstract

Indoor sensing is challenging because of the multi-bounce effect, spherical wavefront, and spatial nonstationarity (SNS) of the near-field effect. This paper addresses radio-based environment sensing considering these issues. Specifically, graph theory (GT) is used to model the multi-bounce propagation of the near field. In this manner, indoor reflectors/scatterers are modeled as vertices in a propagation graph, the multi-bounce paths are modeled by the edges linking the vertices. Besides, the coupled multipath parameters in the near field, i.e., range and angles, are denoted directly by the coordinates of vertices. Then, the space-alternating generalized expectation-maximization (SAGE) algorithm is adapted to the proposed GT-based... (More)

Indoor sensing is challenging because of the multi-bounce effect, spherical wavefront, and spatial nonstationarity (SNS) of the near-field effect. This paper addresses radio-based environment sensing considering these issues. Specifically, graph theory (GT) is used to model the multi-bounce propagation of the near field. In this manner, indoor reflectors/scatterers are modeled as vertices in a propagation graph, the multi-bounce paths are modeled by the edges linking the vertices. Besides, the coupled multipath parameters in the near field, i.e., range and angles, are denoted directly by the coordinates of vertices. Then, the space-alternating generalized expectation-maximization (SAGE) algorithm is adapted to the proposed GT-based dictionary-aided multi-bounce SAGE (GM-SAGE), where the searching parameters including range and angle of departure/arrival (AoD/AoA) are transformed to the coordinates of vertices in the graph. To accelerate the two-bounce sensing, a recursive strategy is proposed. Furthermore, geometric information-based radio-sensing ambiguities are analyzed. The proposed algorithm is validated through a synthetic scattering channel and realistic ray tracing (RT) in a complex indoor office. The results demonstrate that the proposed GM-SAGE can deal with multi-bounce channels, where the one-bounce paths and near-field two-bounce paths are used to reconstruct the scatterers in the environment, the residual higher-bounce paths are identified and hence avoid ghost/mirror detection. Numerical simulations also show the influence of signal-noise ratio (SNR), grid size of vertices, aperture size, and near-far-field effects.

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author
; ; and
organization
publishing date
type
Contribution to journal
publication status
published
subject
keywords
Channel parameter estimation, GM-SAGE, graph theory, indoor sensing, multi-bounce paths, radio SLAM
in
IEEE Transactions on Wireless Communications
volume
24
issue
5
pages
16 pages
publisher
IEEE - Institute of Electrical and Electronics Engineers Inc.
external identifiers
  • scopus:85217638171
ISSN
1536-1276
DOI
10.1109/TWC.2025.3537081
language
English
LU publication?
yes
additional info
Publisher Copyright: © 2002-2012 IEEE.
id
c64099db-8f16-4f88-b4be-f67e0cc9db50
date added to LUP
2025-07-04 14:21:09
date last changed
2025-07-04 14:22:19
@article{c64099db-8f16-4f88-b4be-f67e0cc9db50,
  abstract     = {{<p>Indoor sensing is challenging because of the multi-bounce effect, spherical wavefront, and spatial nonstationarity (SNS) of the near-field effect. This paper addresses radio-based environment sensing considering these issues. Specifically, graph theory (GT) is used to model the multi-bounce propagation of the near field. In this manner, indoor reflectors/scatterers are modeled as vertices in a propagation graph, the multi-bounce paths are modeled by the edges linking the vertices. Besides, the coupled multipath parameters in the near field, i.e., range and angles, are denoted directly by the coordinates of vertices. Then, the space-alternating generalized expectation-maximization (SAGE) algorithm is adapted to the proposed GT-based dictionary-aided multi-bounce SAGE (GM-SAGE), where the searching parameters including range and angle of departure/arrival (AoD/AoA) are transformed to the coordinates of vertices in the graph. To accelerate the two-bounce sensing, a recursive strategy is proposed. Furthermore, geometric information-based radio-sensing ambiguities are analyzed. The proposed algorithm is validated through a synthetic scattering channel and realistic ray tracing (RT) in a complex indoor office. The results demonstrate that the proposed GM-SAGE can deal with multi-bounce channels, where the one-bounce paths and near-field two-bounce paths are used to reconstruct the scatterers in the environment, the residual higher-bounce paths are identified and hence avoid ghost/mirror detection. Numerical simulations also show the influence of signal-noise ratio (SNR), grid size of vertices, aperture size, and near-far-field effects.</p>}},
  author       = {{Liu, Yuan and Wu, Linlong and Cai, Xuesong and Shankar, M. R.Bhavani}},
  issn         = {{1536-1276}},
  keywords     = {{Channel parameter estimation; GM-SAGE; graph theory; indoor sensing; multi-bounce paths; radio SLAM}},
  language     = {{eng}},
  number       = {{5}},
  pages        = {{4219--4234}},
  publisher    = {{IEEE - Institute of Electrical and Electronics Engineers Inc.}},
  series       = {{IEEE Transactions on Wireless Communications}},
  title        = {{Graph-Based Multi-Bounce Modeling and Channel Parameter Estimation for Indoor Sensing}},
  url          = {{http://dx.doi.org/10.1109/TWC.2025.3537081}},
  doi          = {{10.1109/TWC.2025.3537081}},
  volume       = {{24}},
  year         = {{2025}},
}