The distributedbayesian vector parameter estimation problem based on low-resolution observations is investigated in a network, where each node represents an ensemble of estimates from a large number of sensors. A noi...
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The distributedbayesian vector parameter estimation problem based on low-resolution observations is investigated in a network, where each node represents an ensemble of estimates from a large number of sensors. A noise-enhanced bayesian vector estimator that benefits from artificially added noise is proposed. For a network node composed of a sufficiently large number of identical low-resolution sensors, a lemma governing the weight coefficients is proven, and low-cost calculation expressions of the designed estimator and its bayesian mean square error (MSE) are derived by avoiding costly computations due to high-dimensional matrix inversions. Experimental results show that by intentionally adding an appropriate amount of noise to networks of the low-resolution sensors, the MSE of the designed bayesian vector estimator can be significantly reduced. (C) 2021 Elsevier Inc. All rights reserved.
In this paper, we address the optimal quantizer design problem for distributedbayesian parameter estimation with one-bit quantization at local sensors. A performance limit obtained for any distributed parameter estim...
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In this paper, we address the optimal quantizer design problem for distributedbayesian parameter estimation with one-bit quantization at local sensors. A performance limit obtained for any distributed parameter estim...
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ISBN:
(纸本)9781479999897
In this paper, we address the optimal quantizer design problem for distributedbayesian parameter estimation with one-bit quantization at local sensors. A performance limit obtained for any distributed parameter estimator with a known prior is adopted as a guidance for quantizer design. Aided by the performance limit, the optimal quantizer and a set of noisy observation models that achieve the performance limit are derived. Further, when the performance limit may not be achievable for some applications, we develop a near-optimal estimator which consists of a dithered noise and a single threshold quantizer. In the scenario where the parameter is Gaussian and signal-to-noise ratio is greater than -1.138 dB, we show that one can construct such an estimator that achieves approximately 99.65% of the performance limit.
In this paper, a performance limit is derived for a distributedbayesian parameter estimation problem in sensor networks where the prior probability density function of the parameter is known. The sensor observations ...
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ISBN:
(纸本)9781467391696
In this paper, a performance limit is derived for a distributedbayesian parameter estimation problem in sensor networks where the prior probability density function of the parameter is known. The sensor observations are assumed conditionally independent and identically distributed given the parameter to be estimated, and the sensors employ independent and identical quantizers. The performance limit is established in terms of the best possible asymptotic performance that a distributedestimation scheme can achieve for all possible sensor observation models. This performance limit is obtained by deriving the optimal probabilistic quantizer under the ideal setting, where the sensors observe the parameter directly without any noise or distortion. With a uniform prior, the derived bayesian performance limit and the associated quantizer are the same as the previous developed performance limit and quantizers under the minimax framework, where the parameter is assumed to be fixed but unknown. This proposed performance limit under distributedbayesian setting is compared against a widely used performance bound that is based on full-precision sensor observations. This comparison shows that the performance limit derived in this paper is comparatively much tighter in most meaningful signal-to-noise ratio (SNR) regions. Moreover, unlike the unquantized observations performance limit which can never be achieved, this performance limit can be achieved under certain noise observation models.
We introduce in this paper a cooperative-based augmentation system for aircraft positioning. To that end, we derive a distributedestimation algorithm for cooperative localization over a network of aircraft that are p...
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We introduce in this paper a cooperative-based augmentation system for aircraft positioning. To that end, we derive a distributedestimation algorithm for cooperative localization over a network of aircraft that are partially connected by communication links and are also connected to ground-based anchor nodes. The proposed framework assumes that only a subset of the aircraft may have access to GPS measurements to perform local state estimation, and that the different aircraft exchange messages with neighboring nodes on the network to improve their own state estimates. Simulation results show that cooperation significantly reduces the average 3D root mean-square localization error when part of the aircraft are flying dead-reckoning and that the average vertical error cumulative distribution function remains below 4 meters for 95% of time when all aircraft have access to GPS measurements.
Ionospheric scintillation causes major impairments to Global Navigation Satellite System (GNSS) in low-latitude regions. In severe scenarios, this event can lead to complete loss of lock, thus making GNSS measurements...
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Ionospheric scintillation causes major impairments to Global Navigation Satellite System (GNSS) in low-latitude regions. In severe scenarios, this event can lead to complete loss of lock, thus making GNSS measurements unusable for navigation. In this paper, we derive a cooperative localization algorithm where a set of partially connected aircraft exchange messages with neighboring nodes on the network to improve their own position estimates. We consider the scintillation events as abrupt changes in the measurement variance, which are modeled by a discrete-valued Markov process at the nodes which have access to GNSS measurements. Simulation results show that Markovian modeling and cooperation via factor graph message passing reduce the average 3D root mean square localization error and yield an average vertical position error that meets civil aviation standards for approach and landing.
We propose a fully distributed methodology based on factor graphs for joint cooperative localization and distributed noncooperative target tracking in a 3-D scenario where multiple surveillance aircraft fly in formati...
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We propose a fully distributed methodology based on factor graphs for joint cooperative localization and distributed noncooperative target tracking in a 3-D scenario where multiple surveillance aircraft fly in formation without access to global navigation satellite system (GNSS) measurements or communication with anchor nodes. Our approach is based on the adapt-then-combine (ATC) diffusion scheme, which is integrated into the factor graph by the introduction of special combine factors to perform geometric average fusion of the target beliefs over a partially connected network. The updated target belief held by each aircraft following the combine step is also fed back to improve the aircraft's own self-localization, assimilating the target measurements. Simulation results show that the proposed distributed algorithm performed close to the posterior Cramer-Rao lower bound of the optimal centralized solution and that the agents approached a consensus about the target state estimate.
We introduce in this article a distributed factor-graph-based algorithm for anchorless cooperative aircraft localization in a GNSS-denied scenario without fixed infrastructure. The agents use terrain-aided navigation ...
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We introduce in this article a distributed factor-graph-based algorithm for anchorless cooperative aircraft localization in a GNSS-denied scenario without fixed infrastructure. The agents use terrain-aided navigation (TAN) to perform local position estimation and exchange messages to improve their position beliefs. Internode communication cost is reduced using a hybrid Gaussian mixture model / sequential Monte Carlo (GMM/SMC) approach. Simulation results show that, even in a partially connected network where only a small part of the agents perform TAN, cooperation yields better results than all aircraft performing TAN independently.
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