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A 28-GHz multibeam joint communication and sensing system called SideSense is presented, in which a line-of-sight (LoS) beam is used to maintain reliable communication, while other sensing beams are used to enhance physiological motion detection. SideSense decodes the motion frequency and shape from the channel state information (CSI) by first tuning the gain ratio and phase differences between the LoS communication beam and non-LoS (NLoS) beam to maximize the sensing signal-to-noise ratio (SSNR) without significantly degrading the communication channel capacity (CCC). Analytical results based on a bistatic model are presented to show a gain ratio of around 1 and a phase difference of 90° or 270°, which are ideal for optimizing both SSNR and CCC. Experiments based on an array of phased array (APA) beamformers and orthogonal frequency-division multiplexing (OFDM) waveforms with phantom and human subjects are presented to validate the performance of SideSense. Results show that SideSense can improve SSNR by 84% while reducing CCC by 35%, an acceptable decrease within the normal operational parameters of a millimeter-wave (mmWave) communication system, which would not trigger a link reestablishment procedure, e.g., communication beam realignment.
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mmFlexible: Flexible Directional Frequency Multiplexing for Multi-user mmWave Networks
Modern mmWave systems have limited scalability due to inflexibility in performing frequency multiplexing. All the frequency components in the signal are beamformed to one direction via pencil beams and cannot be streamed to other user directions. We present a new flexible mmWave system called mmFlexible, which enables flexible directional frequency multiplexing. In this system, different frequency components of the mmWave signal are beamformed in multiple arbitrary directions with the same pencil beam. Our system makes two key contributions: (1) We propose a novel mmWave front-end architecture, called a delay-phased array, that utilizes a variable delay and variable phase element to create the desired frequency-direction response. (2) We propose a novel algorithm called FSDA (Frequency-space to delay-antenna) to estimate delay and phase values for the real-time operation of the delay-phased array. Through evaluations using mmWave channel traces, we demonstrate that mmFlexible achieves a 60-150% reduction in worst-case latency compared to the baselines.
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- Award ID(s):
- 2211805
- PAR ID:
- 10598543
- Publisher / Repository:
- IEEE
- Date Published:
- ISBN:
- 979-8-3503-3414-2
- Page Range / eLocation ID:
- 1 to 10
- Format(s):
- Medium: X
- Location:
- New York City, NY, USA
- Sponsoring Org:
- National Science Foundation
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- Free Publicly Accessible Full Text
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Accepted Manuscript1.0
- Conference Paper:
- https://doi.org/10.1109/INFOCOM53939.2023.10229065
