Periodic Reporting for period 1 - 6G-ISLAC (Integrated Sensing, Localization, and Communications in 6G THz Systems)
Reporting period: 2023-01-01 to 2024-12-31
We will pioneer high-accuracy SA and SAC by leveraging the technological enablers THz frequencies, larger bandwidths, larger antenna arrays, RISs, beamspace processing, and ML. To achieve the
goal, we set up the following specific objectives, which will handle several of the fundamental challenges in B5G communications and high-accuracy SA, associated with the following three objectives.
1. Communication channel modeling: We will develop and extend channel models (including hardware models) for B5G SAC with THz frequencies, dense antenna arrays, and GHz bandwidths, focusing particularly on new propagation models of the RISs and EM properties of objects, spatial and temporal consistency, and high mobility.
2 Development of SA methods: Exploiting the estimated channel parameters of B5G signals, based on the extended channel models, we will develop methods for estimating the state (e.g. 3D position, 3D orientation, and clock bias) of users, as well as for mapping the time-varying propagation environment characterized by the RISs and EM properties of objects.
3 Communication quality improvement for B5G SAC: Based on the estimated user states and propagation environment by the developed SA methods, we will develop SAC methods to overcome the challenges in B5G communication, supporting beam alignment, beam tracking, power allocation, channel estimation, blockage avoidance, and mobility prediction.
goal, we set up the following specific objectives, which will handle several of the fundamental challenges in B5G communications and high-accuracy SA, associated with the following three objectives.
1. Communication channel modeling: We will develop and extend channel models (including hardware models) for B5G SAC with THz frequencies, dense antenna arrays, and GHz bandwidths, focusing particularly on new propagation models of the RISs and EM properties of objects, spatial and temporal consistency, and high mobility.
2 Development of SA methods: Exploiting the estimated channel parameters of B5G signals, based on the extended channel models, we will develop methods for estimating the state (e.g. 3D position, 3D orientation, and clock bias) of users, as well as for mapping the time-varying propagation environment characterized by the RISs and EM properties of objects.
3 Communication quality improvement for B5G SAC: Based on the estimated user states and propagation environment by the developed SA methods, we will develop SAC methods to overcome the challenges in B5G communication, supporting beam alignment, beam tracking, power allocation, channel estimation, blockage avoidance, and mobility prediction.
Due to early termination of this project, I have partially performed the objectives and activities by obeying the Gantt chart. Thus, I have only done for technical and scientific part with the following works.
1. RISs and Sidelink Communications in Smart Cities: The Key to Seamless Localization and Sensing
- We argue that he emerging technologies of reconfigurable intelligent surfaces (RISs) and sidelink communications constitute the key to providing ubiquitous coverage for localization and sensing in smart cities with low-cost and energy-efficient technical solutions. To this end, we propose and evaluate AP-coordinated and self-coordinated RIS-enabled architectures and detail three groups of application scenarios, relying on low-complexity beacons, cooperative localization, and full-duplex transceivers. A list of practical issues and consequent open research challenges of the proposed localization and sensing systems is also provided.
2. RIS-Enabled and Access-Point-Free Simultaneous Radio Localization and Mapping
- We propose a novel framework of RIS-enabled radio SLAM for wireless operation without the intervention of access points (APs). We first design the RIS phase profiles leveraging prior information for the user equipment (UE), such that they uniformly illuminate the angular sector where the UE is probabilistically located. Second, we modify the marginal Poisson multi-Bernoulli SLAM filter and estimate the UE state and landmarks, which enables efficient mapping of the radio propagation environment. Third, we derive the theoretical Cram ́er-Rao lower bounds on the estimators for the channel parameters and the UE state.
3. Set-Type Belief Propagation with Applications to Mapping, MTT, SLAM, and SLAT
- We first develop BP rules for set-type random variables and demonstrate that vector-type BP is a special case of set-type BP. We further propose factor graphs with set-factor and set-variable nodes by devising the set-factor nodes that can address the set-variables with random elements and cardinality, while the number of vector elements in vector-type is known. To demonstrate the validity of developed set-type BP, we apply it to the Poisson multi-Bernoulli (PMB) filter for simultaneous localization and mapping (SLAM), which naturally leads to a new set-type BP-SLAM filter. Finally, we reveal connections between the vector-type BP-SLAM filter and the proposed set-type BP-SLAM filter.
1. RISs and Sidelink Communications in Smart Cities: The Key to Seamless Localization and Sensing
- We argue that he emerging technologies of reconfigurable intelligent surfaces (RISs) and sidelink communications constitute the key to providing ubiquitous coverage for localization and sensing in smart cities with low-cost and energy-efficient technical solutions. To this end, we propose and evaluate AP-coordinated and self-coordinated RIS-enabled architectures and detail three groups of application scenarios, relying on low-complexity beacons, cooperative localization, and full-duplex transceivers. A list of practical issues and consequent open research challenges of the proposed localization and sensing systems is also provided.
2. RIS-Enabled and Access-Point-Free Simultaneous Radio Localization and Mapping
- We propose a novel framework of RIS-enabled radio SLAM for wireless operation without the intervention of access points (APs). We first design the RIS phase profiles leveraging prior information for the user equipment (UE), such that they uniformly illuminate the angular sector where the UE is probabilistically located. Second, we modify the marginal Poisson multi-Bernoulli SLAM filter and estimate the UE state and landmarks, which enables efficient mapping of the radio propagation environment. Third, we derive the theoretical Cram ́er-Rao lower bounds on the estimators for the channel parameters and the UE state.
3. Set-Type Belief Propagation with Applications to Mapping, MTT, SLAM, and SLAT
- We first develop BP rules for set-type random variables and demonstrate that vector-type BP is a special case of set-type BP. We further propose factor graphs with set-factor and set-variable nodes by devising the set-factor nodes that can address the set-variables with random elements and cardinality, while the number of vector elements in vector-type is known. To demonstrate the validity of developed set-type BP, we apply it to the Poisson multi-Bernoulli (PMB) filter for simultaneous localization and mapping (SLAM), which naturally leads to a new set-type BP-SLAM filter. Finally, we reveal connections between the vector-type BP-SLAM filter and the proposed set-type BP-SLAM filter.