| 1. |
- Ge, Yu, 1995, et al.
(author)
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Experimental Validation of Single Base Station 5G mm Wave Positioning: Initial Findings
- 2022
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In: 2022 25th International Conference on Information Fusion, FUSION 2022. - Piscataway : IEEE.
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Conference paper (peer-reviewed)abstract
- 5G cellular networks can utilize millimeter wave signals, and support large bandwidths and large antenna arrays, which provide more geometric-based signals and higher delay and angle resolutions. These merits bring new opportunities in positioning the user with limited infrastructure through the use of combined angle and delay information. However, there are many practical challenges to overcome, in order to have a functioning single base station 5G mmWave positioning system. In this paper, we describe a deployed single base station mmWave positioning system, and provide an example of the measurement data. Furthermore, we perform measurement validation on a limited measurement data set by performing base station localization. Additional evaluations performed on simulation model data provide guidelines on the required size of the data set and receiver antenna configuration, which will be implemented in upcoming measurements.
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| 2. |
- Savic, Vladimir, et al.
(author)
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Belief consensus algorithms for fast distributed target tracking in wireless sensor networks
- 2014
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In: Signal Processing. - : Elsevier. - 0165-1684 .- 1872-7557. ; 95, s. 149-160
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Journal article (peer-reviewed)abstract
- In distributed target tracking for wireless sensor networks, agreement on the target state can be achieved by the construction and maintenance of a communication path, in order to exchange information regarding local likelihood functions. Such an approach lacks robustness to failures and is not easily applicable to ad-hoc networks. To address this, several methods have been proposed that allow agreement on the global likelihood through fully distributed belief consensus (BC) algorithms, operating on local likelihoods in distributed particle filtering (DPF). However, a unified comparison of the convergence speed and communication cost has not been performed. In this paper, we provide such a comparison and propose a novel BC algorithm based on belief propagation (BP). According to our study, DPF based on metropolis belief consensus (MBC) is the fastest in loopy graphs, while DPF based on BP consensus is the fastest in tree graphs. Moreover, we found that BC-based DPF methods have lower communication overhead than data flooding when the network is sufficiently sparse.
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| 3. |
- Aydogdu, Canan, 1978, et al.
(author)
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Radar Interference Mitigation through Active Coordination
- 2021
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In: IEEE National Radar Conference - Proceedings. - : IEEE. - 1097-5659. ; 2021-May, s. 1-6
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Conference paper (peer-reviewed)abstract
- Intelligent transportation is heavily reliant on radar, which have unique robustness under heavy rain/fog/snow and poor light conditions. With the rapid increase of the number of radars used on modern vehicles, most operating in the same frequency band, the risk of radar interference becomes an important issue. As in radio communication, interference can be mitigated through coordination. We present and evaluate two approaches for radar interference coordination, one for FMCW and one for OFDM, and highlight their challenges and opportunities.
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| 4. |
- Carvajal, Gisela, 1983, et al.
(author)
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Comparison of Automotive FMCW and OFDM Radar Under Interference
- 2020
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In: IEEE National Radar Conference - Proceedings. - New York, NY : IEEE. - 1097-5659. ; 2020-September
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Conference paper (peer-reviewed)abstract
- Automotive radars are subject to interference in spectrally congested environments. To mitigate this interference, various waveforms have been proposed. We compare two waveforms (FMCW and OFDM) in terms of their radar performance and robustness to interference, under similar parameter settings. Our results indicate that under proper windowing both waveforms can achieve similar performance, but OFDM is more sensitive to interference.
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| 5. |
- Ge, Yu, 1995, et al.
(author)
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5G SLAM Using the Clustering and Assignment Approach with Diffuse Multipath
- 2020
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In: Sensors. - : MDPI AG. - 1424-8220. ; 20:16, s. 1-31
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Journal article (peer-reviewed)abstract
- 5G communication systems operating above 24 GHz have promising properties for user localization and environment mapping. Existing studies have either relied on simplified abstract models of the signal propagation and the measurements, or are based on direct positioning approaches, which directly map the received waveform to a position. In this study, we consider an intermediate approach, which consists of four phases-downlink data transmission, multi-dimensional channel estimation, channel parameter clustering, and simultaneous localization and mapping (SLAM) based on a novel likelihood function. This approach can decompose the problem into simpler steps, thus leading to lower complexity. At the same time, by considering an end-to-end processing chain, we are accounting for a wide variety of practical impairments. Simulation results demonstrate the efficacy of the proposed approach.
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| 6. |
- Hult, Robert, 1984, et al.
(author)
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Coordination of Cooperative Autonomous Vehicles: Toward safer and more efficient road transportation
- 2016
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In: IEEE Signal Processing Magazine. - : Institute of Electrical and Electronics Engineers (IEEE). - 1558-0792 .- 1053-5888. ; 33:6, s. 74-84
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Journal article (peer-reviewed)abstract
- While intelligent transportation systems come in many shapes and sizes, arguably the most transformational realization will be the autonomous vehicle. As such vehicles become commercially available in the coming years, first on dedicated roads and under specific conditions, and later on all public roads at all times, a phase transition will occur. Once a sufficient number of autonomous vehicles is deployed, the opportunity for explicit coordination appears. This article treats this challenging network control problem, which lies at the intersection of control theory, signal processing, and wireless communication. We provide an overview of the state of the art, while at the same time highlighting key research directions for the coming decades.
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| 7. |
- Hult, Robert, 1984, et al.
(author)
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Optimisation-based coordination of connected, automated vehicles at intersections
- 2020
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In: Vehicle System Dynamics. - : Informa UK Limited. - 1744-5159 .- 0042-3114. ; 58:5, s. 726-747
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Journal article (peer-reviewed)abstract
- In this paper, we analyse the performance of a model predictive controller for coordination of connected, automated vehicles at intersections. The problem has combinatorial complexity, and we propose to solve it approximately by using a two stage procedure where (1) the vehicle crossing order in which the vehicles cross the intersection is found by solving a mixed integer quadratic program and (2) the control commands are subsequently found by solving a nonlinear program. We show that the controller is persistently safe and compare its performance against traffic lights and two simpler optimisation-based coordination schemes. The results show that our approach outperforms the considered alternatives in terms of both energy consumption and travel-time delay, especially for medium to high traffic loads.
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| 8. |
- Kang, Jeongwan, et al.
(author)
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Optimized Switching Between Sensing and Communication for mmWave MU-MISO Systems
- 2022
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In: 2022 Ieee International Conference On Communications Workshops (Icc Workshops). - : Institute of Electrical and Electronics Engineers (IEEE). ; , s. 498-503
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Conference paper (peer-reviewed)abstract
- In this paper, we propose a scheme optimizing the per-user channel sensing duration in millimeter-wave (mmWave) multi-user multiple-input single-output (MU-MISO) systems. For each user, the BS predicts the effective rate to be achieved after pilot transmission. Then, the channel sensing duration of each user is optimized by ending the pilot transmission when the predicted rate is lower than the current rate. The robust regularized zero-forcing (RRZF) precoder and equal power allocation (EPA) are adopted to transmit sensing pilots and data. Numerical results show that the more severe the interference among users, the longer channel sensing duration is required. Moreover, the proposed scheme results in a higher sum rate compared to benchmark schemes.
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| 9. |
- Srinivasan, Muralikrishnan, 1991, et al.
(author)
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End-to-End Learning for VCSEL-based Optical Interconnects: State-of-the-Art, Challenges, and Opportunities
- 2023
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In: Journal of Lightwave Technology. - 0733-8724 .- 1558-2213. ; 41:11, s. 3261-3277
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Journal article (peer-reviewed)abstract
- Optical interconnects (OIs) based on vertical-cavity surface-emitting lasers (VCSELs) are the main workhorse within data centers, supercomputers, and even vehicles, providing low-cost, high-rate connectivity. VCSELs must operate under extremely harsh and time-varying conditions, thus requiring adaptive and flexible designs of the communication chain. Such designs can be built based on mathematical models (model-based design) or learned from data (machine learning (ML) based design). Various ML techniques have recently come to the forefront, replacing individual components in the transmitters and receivers with deep neural networks. Beyond such component-wise learning, end-to-end (E2E) autoencoder approaches can reach the ultimate performance through co-optimizing entire parameterized transmitters and receivers. This tutorial paper aims to provide an overview of ML for VCSEL-based OIs, with a focus on E2E approaches, dealing specifically with the unique challenges facing VCSELs, such as the wide temperature variations and complex models.
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| 10. |
- Zheng, Pinjun, et al.
(author)
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Coverage Analysis of Joint Localization and Communication in THz Systems with 3D Arrays
- 2023
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In: IEEE Transactions on Wireless Communications. - 1558-2248 .- 1536-1276. ; In Press
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Journal article (peer-reviewed)abstract
- As a key enabler of Terahertz (THz)-based wireless technologies, large-scale multiple-input-multiple-output systems are well known for their advantages in both communication and localization. Contrary to existing works that mostly focus on planar arrays, this paper first explores the potential of three-dimensional (3D) spatial array structures in joint localization and communication coverage enhancement. We consider a THz-band wireless system where a user is equipped with a 3D array receiving downlink far-field signals from multiple base stations with known positions and orientations over Rician fading channels. First, we derive the constrained Cramér-Rao bound (CCRB) for the localization (i.e., position and orientation estimation) performance, based on which we define the localization coverage metrics. Then, we derive the communication key performance indicators (KPIs) including instantaneous signal-to-noise ratio, outage probability, and ergodic capacity, and define the corresponding coverage metrics. To facilitate localization applications using 3D arrays, a maximum likelihood-based algorithm for joint user equipment (UE) position and orientation estimation is proposed, which is initialized by a least squares-based solution. Our numerical results show that the 3D array configuration offers overall higher coverage than the planar array w.r.t. both localization and communication KPIs, although with minor performance loss in certain UE positions and orientations. The proposed localization algorithm is also verified to be efficient in simulations as it attains the derived CCRB.
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