scholarly journals Increasing pupil size is associated with improved detection performance in the periphery

2021 ◽  
Author(s):  
Lisa Valentina Eberhardt ◽  
Christoph Strauch ◽  
Tim Samuel Hartmann ◽  
Anke Huckauf
Keyword(s):  
Visible Light ◽  
Pupil Size ◽  
Signal To Noise Ratio ◽  
Detection Performance ◽  
Eye Tracker ◽  
Signal To Noise ◽  
Current Trial ◽  
Spatial Frequencies ◽  
Online Setting ◽  
Pupillary Change

AbstractVisible light enters our body via the pupil. By changing its size, the pupil shapes visual input. Small apertures increase the resolution of high spatial frequencies, thus allowing discrimination of fine details. Large apertures, in contrast, provide a better signal-to-noise ratio, because more light can enter the eye. This should lead to better detection performance of peripheral stimuli. Experiment 1 shows that the effect can reliably be demonstrated even in a less controlled online setting. In Experiment 2, pupil size was measured in a laboratory using an eye tracker. The findings replicate findings showing that large pupils provide an advantage for peripheral detection of faint stimuli. Moreover, not only pupil size during information intake in the current trial n, but also its interaction with pupil size preceding information intake, i.e., in trial n-1, predicted performance. This suggests that in addition to absolute pupil size, the extent of pupillary change provides a mechanism to modulate perceptual functions. The results are discussed in terms of low-level sensory as well as higher-level arousal-driven changes in stimulus processing.

scholarly journals A Full-Duplex LED-to-LED Visible Light Communication System

Electronics ◽  
2020 ◽  
Vol 9 (10) ◽  
pp. 1713
Author(s):  
Hyunwoo Jung ◽  
Sung-Man Kim
Keyword(s):  
Visible Light ◽  
Bit Error Rate ◽  
Error Rate ◽  
Signal To Noise Ratio ◽  
Light Emitting Diode ◽  
Visible Light Communication ◽  
Full Duplex ◽  
Signal To Noise ◽  
Light Emitting ◽  
Half Duplex

We experimentally demonstrated full-duplex light-emitting diode (LED)-to-LED visible light communication (VLC) using LEDs as the transmitter and receiver. Firstly, we investigated the performance dependency on the wavelengths of the LED transmitter and receiver by measuring the rise time and signal-to-noise ratio (SNR). Through the investigation, we were able to choose the optimal LED color set for LED-to-LED VLC using Shannon’s channel capacity law. The bit error rate (BER) results of full-duplex and half-duplex LED-to-LED VLC systems with the optimal LED sets are shown to compare the performance. Furthermore, we discuss major distortions and signal losses in the full-duplex LED-to-LED VLC system.

scholarly journals Polarization Differential Visible Light Communication: Theory and Experimental Evaluation

Sensors ◽  
2020 ◽  
Vol 20 (19) ◽  
pp. 5661
Author(s):  
Jorik De Bruycker ◽  
Willem Raes ◽  
Stanislav Zvánovec ◽  
Nobby Stevens
Keyword(s):  
Visible Light ◽  
Communication Theory ◽  
Rotation Angle ◽  
Signal To Noise Ratio ◽  
Visible Light Communication ◽  
Signal Quality ◽  
Polarization Direction ◽  
Signal To Noise ◽  
Research Attention ◽  
Analytical Expression

Visible Light Communication (VLC) has received substantial research attention in the last decade. The vast majority of VLC focuses on the modulation of the transmitted light intensity. In this work, however, the intensity is kept constant while the polarization direction is deployed as a carrier of information. Demodulation is realized by using a differential receiver pair equipped with mutually orthogonal polarizers. An analytical expression to evaluate the Signal-to-Noise Ratio (SNR) as a function of the rotation angle of the receiver is derived. It is demonstrated that the signal quality can deteriorate heavily with receiver orientation when using a single differential receiver pair. A way to overcome this drawback using two receiver pairs is described. The analytical expression is experimentally verified through measurements with two different receiver setups. This work demonstrates the potential of polarization-based modulation in the field of VLC, where receiver rotation robustness has been achieved by means of a dedicated quadrant photodiode receiver.

scholarly journals An Optimization of the Signal-to-Noise Ratio Distribution of an Indoor Visible Light Communication System Based on the Conventional Layout Model

2020 ◽  
Vol 12 (21) ◽  
pp. 9006
Author(s):  
Xiangyang Zhang ◽  
Nan Zhao ◽  
Fadi Al-Turjman ◽  
Muhammad Bilal Khan ◽  
Xiaodong Yang
Keyword(s):  
Visible Light ◽  
Communication System ◽  
Signal To Noise Ratio ◽  
Visible Light Communication ◽  
Optimal Layout ◽  
Signal To Noise ◽  
Ratio Distribution ◽  
Channel Quality ◽  
Reflected Light ◽  
Noise Ratio

For an actual visible light communication system, it is necessary to consider the uniformity of indoor illumination. Most of the existing optimization schemes, however, do not consider the effect of the first reflected light, and do not conform to the practical application conventions, which increases the actual cost and the complexity of system construction. In this paper, considering the first reflected light and based on the conventional layout model and the classic indoor visible light communication model, a scheme using the parameter Q to determine the optimal layout of channel quality is proposed. We determined the layout, and then carried out a simulation. For comparison, the normal layout and the optimal layout of illumination were also simulated. The simulation results show that the illuminance distributions of the three layouts meet the standards of the International Organization for Standardization. The optimal layout of channel quality in the signal-to-noise ratio distribution, maximum delay spread distribution, and impulse response is obviously better than the optimal layout of illumination. In particular, the effective area percentage of the optimal layout of channel quality is increased by 0.32% and 6.08% to 88.80% as compared with the normal layout’s 88.48% and the optimal layout of illumination’s 82.72%. However, compared with the normal layout, the advantages are not very prominent.

scholarly journals On the Achievable Information Rate of Probabilistic Shaping QAM Order and Source Entropy in Visible Light Communication Systems

2020 ◽  
Vol 10 (12) ◽  
pp. 4299 ◽  
Author(s):  
Peng Zou ◽  
Fangchen Hu ◽  
Yiheng Zhao ◽  
Nan Chi
Keyword(s):  
Visible Light ◽  
Communication Systems ◽  
Signal To Noise Ratio ◽  
Visible Light Communication ◽  
Spectrum Efficiency ◽  
Information Rate ◽  
Computation Complexity ◽  
Signal To Noise ◽  
First Time ◽  
The Relationship

Probabilistic shaping (PS) is a powerful tool that can realize a flexible data rate and high spectrum efficiency. However, the performance of PS is closely related to the quadrature amplitude modulation (QAM) order, source entropy (SE), normalized generalized mutual information (NGMI), and achievable information rate (AIR). In this paper, we investigated the relationship between PS QAM order, SE, NGMI, and AIR performance for the first time in the visible light communication (VLC) system. Under a specific signal-to-noise ratio (SNR), the PS QAM order and SE in this paper can realize a high AIR at a preset NGMI threshold with the lowest computation complexity, which is just 0.1 bit smaller than the highest AIR. Simulation and experimental results show that the NGMI fluctuates between only ±0.005 of the preset NGMI threshold, which proves that the scheme proposed in this paper is feasible.

scholarly journals Analysis Study of Radar Probability of Detection for Fluctuating and Non-fluctuating Targets

2017 ◽  
Vol 2 (1) ◽  
pp. 12-20
Author(s):  
Naceur AOUNALLAH ◽  
Ali KHALFA
Keyword(s):  
Detection Probability ◽  
Signal To Noise Ratio ◽  
False Alarm Probability ◽  
Detection Performance ◽  
Probability Of Detection ◽  
Statistical Techniques ◽  
Signal To Noise ◽  
Analysis Study ◽  
Graphical Simulation ◽  
Probability Number

The radar analyst can develop and use mathematical and statistical techniques that lead to accurate prediction or adapting models for estimating the target detection performance. In radar detection theory, detection probability, false alarm probability, number of samples non-coherently integrated for a detection test, and signal-to-noise ratio (SNR) are closely interrelated. The present paper is intended to provide an overview of the calculations of radar probability of detection and its related parameters. The main methods and procedures for predicting the detection performance of either non-fluctuating or fluctuating targets are described. Performance’s analysis of the studied models is included, along with some graphical simulation examples.

Sign in / Sign up

Export Citation Format

Share Document