38 research outputs found
Multi-User Matching and Resource Allocation in Vision Aided Communications
Visual perception is an effective way to obtain the spatial characteristics
of wireless channels and to reduce the overhead for communications system. A
critical problem for the visual assistance is that the communications system
needs to match the radio signal with the visual information of the
corresponding user, i.e., to identify the visual user that corresponds to the
target radio signal from all the environmental objects. In this paper, we
propose a user matching method for environment with a variable number of
objects. Specifically, we apply 3D detection to extract all the environmental
objects from the images taken by multiple cameras. Then, we design a deep
neural network (DNN) to estimate the location distribution of users by the
images and beam pairs at multiple moments, and thereby identify the users from
all the extracted environmental objects. Moreover, we present a resource
allocation method based on the taken images to reduce the time and spectrum
overhead compared to traditional resource allocation methods. Simulation
results show that the proposed user matching method outperforms the existing
methods, and the proposed resource allocation method can achieve
transmission rate of the traditional resource allocation method but with the
time and spectrum overhead significantly reduced.Comment: 34 pages, 21 figure
Uncertainty Modulates the Effect of Transcranial Stimulation Over the Right Dorsolateral Prefrontal Cortex on Decision-Making Under Threat
Threat is a strategy that can be used to impact decision-making processes in bargaining. Abundant evidence suggests that credible threat and incredible threat both influence the obeisance of others. However, it is not clear whether the decision-making processes under credible threat and incredible threat during bargaining involve differential neurocognitive mechanisms. Here, we employed cathodal transcranial direct current stimulation (tDCS) to deactivate the right dorsolateral prefrontal cortex (rDLPFC) to address this question while subjects allocated and reported the subjective probability of future rejection under incredible threat and credible threat. We found that application of cathodal tDCS over the rDLPFC decreased the proposer’s subjective inference of probability of rejection and the offer to the responder under incredible threat. Conversely, the same stimulation did not lead to a significant difference compared to the sham group in subjective probability and offer under credible threat. These results suggested that decision-making processes under the two types of threat during bargaining were associated with different neurocognitive substrates, because the punishment for non-compliance was uncertain under incredible threat, whereas it was certain under credible threat. We decreased activity in the rDLPFC, which is involved in decision-making processes related to bargaining under incredible threats, and observed significantly impacted behavior. The differential neurocognitive bases of subjective probability of rejection under incredible threat and credible threat resulted in different tDCS effects
Multi-Camera View Based Proactive BS Selection and Beam Switching for V2X
Due to the short wavelength and large attenuation of millimeter-wave
(mmWave), mmWave BSs are densely distributed and require beamforming with high
directivity. When the user moves out of the coverage of the current BS or is
severely blocked, the mmWave BS must be switched to ensure the communication
quality. In this paper, we proposed a multi-camera view based proactive BS
selection and beam switching that can predict the optimal BS of the user in the
future frame and switch the corresponding beam pair. Specifically, we extract
the features of multi-camera view images and a small part of channel state
information (CSI) in historical frames, and dynamically adjust the weight of
each modality feature. Then we design a multi-task learning module to guide the
network to better understand the main task, thereby enhancing the accuracy and
the robustness of BS selection and beam switching. Using the outputs of all
tasks, a prior knowledge based fine tuning network is designed to further
increase the BS switching accuracy. After the optimal BS is obtained, a beam
pair switching network is proposed to directly predict the optimal beam pair of
the corresponding BS. Simulation results in an outdoor intersection environment
show the superior performance of our proposed solution under several metrics
such as predicting accuracy, achievable rate, harmonic mean of precision and
recall
Vision Aided Environment Semantics Extraction and Its Application in mmWave Beam Selection
In this letter, we propose a novel mmWave beam selection method based on the
environment semantics that are extracted from camera images taken at the user
side. Specifically, we first define the environment semantics as the spatial
distribution of the scatterers that affect the wireless propagation channels
and utilize the keypoint detection technique to extract them from the input
images. Then, we design a deep neural network with environment semantics as the
input that can output the optimal beam pairs at UE and BS. Compared with the
existing beam selection approaches that directly use images as the input, the
proposed semantic-based method can explicitly obtain the environmental features
that account for the propagation of wireless signals, and thus reduce the
burden of storage and computation. Simulation results show that the proposed
method can precisely estimate the location of the scatterers and outperform the
existing image or LIDAR based works
5G PRS-Based Sensing: A Sensing Reference Signal Approach for Joint Sensing and Communication System
The emerging joint sensing and communication (JSC) technology is expected to
support new applications and services, such as autonomous driving and extended
reality (XR), in the future wireless communication systems. Pilot (or
reference) signals in wireless communications usually have good passive
detection performance, strong anti-noise capability and good auto-correlation
characteristics, hence they bear the potential for applying in radar sensing.
In this paper, we investigate how to apply the positioning reference signal
(PRS) of the 5th generation (5G) mobile communications in radar sensing. This
approach has the unique benefit of compatibility with the most advanced mobile
communication system available so far. Thus, the PRS can be regarded as a
sensing reference signal to simultaneously realize the functions of radar
sensing, communication and positioning in a convenient manner. Firstly, we
propose a PRS based radar sensing scheme and analyze its range and velocity
estimation performance, based on which we propose a method that improves the
accuracy of velocity estimation by using multiple frames. Furthermore, the
Cramer-Rao lower bound (CRLB) of the range and velocity estimation for PRS
based radar sensing and the CRLB of the range estimation for PRS based
positioning are derived. Our analysis and simulation results demonstrate the
feasibility and superiority of PRS over other pilot signals in radar sensing.
Finally, some suggestions for the future 5G-Advanced and 6th generation (6G)
frame structure design containing the sensing reference signal are derived
based on our study
Quantum Computing for MIMO Beam Selection Problem: Model and Optical Experimental Solution
Massive multiple-input multiple-output (MIMO) has gained widespread
popularity in recent years due to its ability to increase data rates, improve
signal quality, and provide better coverage in challenging environments. In
this paper, we investigate the MIMO beam selection (MBS) problem, which is
proven to be NP-hard and computationally intractable. To deal with this
problem, quantum computing that can provide faster and more efficient solutions
to large-scale combinatorial optimization is considered. MBS is formulated in a
quadratic unbounded binary optimization form and solved with Coherent Ising
Machine (CIM) physical machine. We compare the performance of our solution with
two classic heuristics, simulated annealing and Tabu search. The results
demonstrate an average performance improvement by a factor of 261.23 and 20.6,
respectively, which shows that CIM-based solution performs significantly better
in terms of selecting the optimal subset of beams. This work shows great
promise for practical 5G operation and promotes the application of quantum
computing in solving computationally hard problems in communication.Comment: Accepted by IEEE Globecom 202
Neural Dynamics of Processing Probability Weight and Monetary Magnitude in the Evaluation of a Risky Reward
Risky decision-making involves risky reward valuation, choice, and feedback processes. However, the temporal dynamics of risky reward processing are not well understood. Using event-related brain potential, we investigated the neural correlates of probability weight and money magnitude in the evaluation of a risky reward. In this study, each risky choice consisted of two risky options, which were presented serially to separate decision-making and option evaluation processes. The early P200 component reflected the process of probability weight, not money magnitude. The medial frontal negativity (MFN) reflected both probability weight and money magnitude processes. The late positive potential (LPP) only reflected the process of probability weight. These results demonstrate distinct temporal dynamics for probability weight and money magnitude processes when evaluating a risky outcome, providing a better understanding of the possible mechanism underlying risky reward processing