RIS-Enabled SISO Localization under User Mobility and Spatial-Wideband Effects

Abstract

Reconfigurable intelligent surface (RIS) is a promising technological enabler for the 6th generation (6G) of wireless systems with applications in localization and communication. In this paper, we consider the problem of positioning a single-antenna user in 3D space based on the received signal from a single-antenna base station and reflected signal from an RIS by taking into account the mobility of the user and spatial-wideband (WB) effects. To do so, we first derive the spatial-WB channel model under the far-field assumption, for orthogonal frequency-division multiplexing signal transmission with the user having a constant velocity. We derive the Cramer Rao bounds to serve as a benchmark. Furthermore, we devise a low-complexity estimator that attains the bounds in high signal-to-noise ratios. Our estimator neglects the spatial-WB effects and deals with the user mobility by estimating the radial velocities and compensating for their effects in an iterative fashion. We show that the spatial-WB effects can degrade the localization accuracy for large RIS sizes and large signal bandwidths as the direction of arrival or departure deviate from the RIS normal. In particular, for a 64X64 RIS, the proposed estimator is resilient against the spatial-WB effects up to 140 MHz bandwidth. Regarding user mobility, our results suggest that the velocity of the user influences neither the bounds nor the accuracy of our estimator. Specifically, we observe that the state of the user with a high speed (42 m/s) can be estimated virtually with the same accuracy as a static user.

References in corpus (11)

• Wireless Communications with Reconfigurable Intelligent Surface: Path Loss Modeling and Experimental Measurement
• Intelligent Reflecting Surface-Enhanced OFDM: Channel Estimation and Reflection Optimization
• Position and Orientation Estimation through Millimeter Wave MIMO in 5G Systems
• Reconfigurable Intelligent Surfaces: A Signal Processing Perspective With Wireless Applications
• Spatial- and Frequency-Wideband Effects in Millimeter-Wave Massive MIMO Systems
• Beyond Massive-MIMO: The Potential of Positioning with Large Intelligent Surfaces
• Channel Estimation for Intelligent Reflecting Surface Assisted MIMO Systems: A Tensor Modeling Approach
• Reconfigurable Intelligent Surfaces for Doppler Effect and Multipath Fading Mitigation
• Intelligent Reflecting Surface Operation under Predictable Receiver Mobility: A Continuous Time Propagation Model
• Wideband Channel Estimation for IRS-Aided Systems in the Face of Beam Squint
• Frequency Synchronization for Uplink Massive MIMO with Adaptive MUI Suppression in Angle-domain

Cited by in corpus (5)

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• On the Ground and in the Sky: A Tutorial on Radio Localization in Ground-Air-Space Networks
• RIS-Enabled NLoS Near-Field Joint Position and Velocity Estimation under User Mobility
• Enhancing NLoS RIS-Aided Localization with Optimization and Machine Learning
• Zero Access Points 3D Cooperative Positioning via RIS and Sidelink Communications