scholarly journals Spectral Domain-Based Data-Embedding Mechanisms for Display-to-Camera Communication

Electronics ◽  
2021 ◽  
Vol 10 (4) ◽  
pp. 468
Author(s):  
Lakpa Dorje Tamang ◽  
Byung Wook Kim
Keyword(s):  
Data Transmission ◽  
Performance Metrics ◽  
Signal To Noise Ratio ◽  
Data Embedding ◽  
Suitable Candidate ◽  
Analog To Digital ◽  
Optical Channels ◽  
Normal Human ◽  
Human Eyes ◽  
Achievable Data Rate

Recently, digital displays and cameras have been extensively used as new data transmission and reception devices in conjunction with optical camera communication (OCC) technology. This paper presents three types of frequency-based data-embedding mechanisms for a display-to-camera (D2C) communication system, in which a commercial digital display transmits information and an off-the-shelf smartphone camera receives it. For the spectral embedding, sub-band coefficients obtained from a discrete cosine transform (DCT) image and predetermined embedding factors of three embedding mechanisms are used. This allows the data to be recovered from several types of noises induced in wireless optical channels, such as analog-to-digital (A/D) and digital-to-analog (D/A) conversion, rotation, scaling, and translation (RST) effects, while also maintaining the image quality to normal human eyes. We performed extensive simulations and real-world D2C experiments using several performance metrics. Through the analysis of the experimental results, it was shown that the proposed method can be considered as a suitable candidate for the D2C system in terms of the achievable data rate (ADR), peak signal-to-noise ratio (PSNR), and the bit error rate (BER).

scholarly journals New approach for localization and smart data transmission inside underground mine environment

2021 ◽  
Vol 3 (6) ◽  
Author(s):  
Ankita RayChowdhury ◽  
Ankita Pramanik ◽  
Gopal Chandra Roy
Keyword(s):  
Data Transmission ◽  
Signal To Noise Ratio ◽  
Visible Light Communication ◽  
Underground Mine ◽  
Control Room ◽  
Time Data ◽  
New Approach ◽  
Mine Environment ◽  
Surface Control ◽  
Smart Data

AbstractThis paper presents an approach to access real time data from underground mine. Two advance technologies are presented that can improve the adverse environmental effect of underground mine. Visible light communication (VLC) technology is incorporated to estimate the location of miners inside the mine. The distribution of signal to noise ratio (SNR) for VLC system is also studied. In the second part of the paper, long range (LoRa) technology is introduced for transmitting underground information to above the surface control room. This paper also includes details of the LoRa technology, and presents comparison of ranges with existing above the surface technologies.

Study of Wireless Torque Measurement System Based on CC2500

2011 ◽  
Vol 383-390 ◽  
pp. 5300-5303
Author(s):  
Wei Liu ◽  
Xiao Jie Song ◽  
Wen Gang Chen
Keyword(s):  
Signal To Noise Ratio ◽  
Digital Data ◽  
Measuring System ◽  
Instrumentation Amplifier ◽  
Torque Sensor ◽  
Torque Measurement ◽  
Analog To Digital ◽  
Wireless Transceiver ◽  
Precision Measuring ◽  
Transmission Shaft

It’s very difficult to get high precision measuring result using contact torquemeter because of very low signal-to-noise ratio. To overcome this defect, a wireless torque measuring system is designed based on CC2500. This system uses strain gauge torque sensor to measure the surface principal stress of the transmission shaft, and get the maximum shearing stress, and then the torque that the transmission shaft bears. The weak output signal of torque sensor is magnified by the instrumentation amplifier AD623, and sent to the analog-to-digital convertor. These digital data are transmited to the portable receiving terminal by the wireless transceiver chip CC2500. The dynamic wireless torque measurement is realized by this system.

scholarly journals Comparison of corneal irregular astigmatism by the type of corneal regular astigmatism

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Yuta Ueno ◽  
Risa Nomura ◽  
Takahiro Hiraoka ◽  
Katsuhito Kinoshita ◽  
Mutsuko Ohara ◽  
...  
Keyword(s):  
Higher Order ◽  
Stepwise Multiple Regression ◽  
Group Differences ◽  
Corneal Surface ◽  
Fourier Harmonic ◽  
Normal Human ◽  
The Mean ◽  
Human Eyes ◽  
Topography Data ◽  
Irregular Astigmatism

AbstractWe investigated the relation between corneal regular and irregular astigmatism in normal human eyes. In 951 eyes of 951 patients, corneal irregular astigmatism, such as asymmetry and higher-order irregularity components, was calculated using the Fourier harmonic analysis of corneal topography data within the central 3-mm zone of the anterior corneal surface. The eyes were classified by the type of corneal regular astigmatism into four groups; minimum (< 0.75 diopters), with-the-rule (WTR), against-the-rule (ATR), and oblique astigmatism. The mean age was significantly different among the four groups (P < 0.001); patients with WTR astigmatism were the youngest, followed by those with minimum, oblique, and ATR astigmatism. Significant inter-group differences were found among the four groups in asymmetry (P = 0.005) and higher-order irregularity components (P < 0.001); the largest was in eyes with oblique astigmatism, followed by ATR, WTR, and minimum astigmatism. The stepwise multiple regression analysis revealed that corneal regular astigmatism pattern significantly influenced the amount of corneal irregular astigmatism after controlling for confounding factors (P < 0.001). Corneal irregular astigmatism, such as asymmetry and higher order irregularity components, was the largest in eyes with oblique astigmatism, followed by those with ATR, WTR, and minimum astigmatism, even after adjustment for age of subjects.

scholarly journals Fourier Rotman Lens Enabled Directional Modulation Transmitter

2015 ◽  
Vol 2015 ◽  
pp. 1-13 ◽  
Author(s):  
Yuan Ding ◽  
Yunhua Zhang ◽  
Vincent Fusco
Keyword(s):  
Bit Error Rate ◽  
Data Streams ◽  
Data Transmission ◽  
Signal To Noise Ratio ◽  
High Signal ◽  
Independent Data ◽  
Time Data ◽  
Dual Beam ◽  
Directional Modulation ◽  
Ber Performance

A 10 GHz Fourier Rotman lens enabled dynamic directional modulation (DM) transmitter is experimentally evaluated. Bit error rate (BER) performance is obtained via real-time data transmission. It is shown that Fourier Rotman DM functionality enhances system security performance in terms of narrower decodable low BER region and higher BER values associated with BER sidelobes especially under high signal to noise ratio (SNR) scenarios. This enhancement is achieved by controlled corruption of constellation diagrams in IQ space by orthogonal injection of interference. Furthermore, the paper gives the first report of a functional dual-beam DM transmitter, which has the capability of simultaneously projecting two independent data streams into two different spatial directions while simultaneously scrambling the information signals along all other directions.

scholarly journals COMPARATIVE ANALYSIS OF MODULATION SCHEMES USING ADAPTIVE EQUALIZATION AS FADING MITIGATION TECHNIQUE

2012 ◽  
pp. 25-31
Author(s):  
SABITA NAHATA ◽  
SUBRATA BHATTACHARYA
Keyword(s):  
Comparative Analysis ◽  
Data Transmission ◽  
High Speed ◽  
Signal To Noise Ratio ◽  
Multipath Fading ◽  
Symbol Error Rate ◽  
Adaptive Equalization ◽  
Modulation Scheme ◽  
Modulation Schemes ◽  
Mitigation Technique

Inter-symbol interference (ISI) due to multipath fading is a vital problem in high-speed wireless communication which restricts communication quality and capacity. Therefore, in addition to choosing a fading mitigation technique, it is also important to strategically select a modulation scheme for effective data transmission. Recent literature review on wireless standards, such as 3G and 4G indicates that QAM and QPSK are suitable choices for data transmission. In this paper, a comparative analysis on selected modulation schemes is performed in a fading environment. The mitigation of fading is done using adaptive equalization technique. Also, we show that the signal to noise ratio (SNR) is an important parameter to choose. It is observed that, even when an adaptive equalizer is used at the receiver, a very low SNR gives very high symbol error rate (SER). We derive some important conclusions from our simulation result: QPSK shows minimum SER, whereas 256-PSK and 256-PAM perform worse. Given its spectral efficiency and a low SER, the best choice is 256- QAM.

scholarly journals A Comprehensive Approach to Image Watermarking, Encryption and Steganography

2015 ◽  
Vol 8 (4) ◽  
pp. 32
Author(s):  
Sabarish Sridhar
Keyword(s):  
Data Hiding ◽  
Data Transmission ◽  
Mean Squared Error ◽  
Signal To Noise Ratio ◽  
Image Watermarking ◽  
Cover Image ◽  
Second Step ◽  
Squared Error ◽  
Feature Similarity ◽  
Secure Data Transmission

Steganography, water marking and encryption are widely used in image processing and communication. A general practice is to use them independently or in combination of two - for e.g. data hiding with encryption or steganography alone. This paper aims to combine the features of watermarking, image encryption as well as image steganography to provide reliable and secure data transmission .The basics of data hiding and encryption are explained. The first step involves inserting the required watermark on the image at the optimum bit plane. The second step is to use an RSA hash to actually encrypt the image. The final step involves obtaining a cover image and hiding the encrypted image within this cover image. A set of metrics will be used for evaluation of the effectiveness of the digital water marking. The list includes Mean Squared Error, Peak Signal to Noise Ratio and Feature Similarity.

The effect of oral metyrapone on aqueous humor dynamics in normal human eyes

2009 ◽  
Vol 68 (5) ◽  
pp. 582-586 ◽  
Author(s):  
Takezo Mito ◽  
Takashi Shiono ◽  
Ryozo Kimura ◽  
Makoto Tamai
Keyword(s):  
Aqueous Humor ◽  
Aqueous Humor Dynamics ◽  
Normal Human ◽  
Human Eyes

To Mitigate the Effect of Cross-Phase Modulation by Employing PC-DCF Technique in Multi-Tone RoF System

2018 ◽  
Vol 0 (0) ◽  
Author(s):  
Namita Kathpal ◽  
Amit Kumar Garg
Keyword(s):  
Optical Networks ◽  
Wavelength Division Multiplexing ◽  
Phase Modulation ◽  
Performance Metrics ◽  
Signal To Noise Ratio ◽  
Optical Signal ◽  
Input Power ◽  
System Capacity ◽  
Bit Rate ◽  
Cross Phase Modulation

AbstractIt is known that the high bandwidth demands are accomplished by deploying the concept of wavelength division multiplexing in optical networks which involves the transmission of multiple wavelength signals spaced very close to each other. Due to closely spaced wavelengths, the signal power of one channel phase modulates the adjacent channel which in turn produces nonlinear effects such as cross-phase modulation (XPM), self-phase modulation (SPM) and four-wave mixing (FWM). Thus, in this paper, PC-DCF (pre-compensating dispersion compensating fiber) technique has been demonstrated and evaluated in the transmission link to compensate the XPM effects, and this result seems to significantly enhance w.r.t. transmission performance and system capacity considering performance metrics such as Optical Signal to Noise Ratio (OSNR), bit rate, Q-factor and bit error rate (BER). It is evident from the simulation results as well as through mathematical modeling that the proposed technique (PC-DCF) provides optimum results at the channel spacing of 100 GHz, bit rate of 10 Gbps and input power of 5 mW which collectively provides a 5 dB increase in OSNR as compared to the existing compensating technique.

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