scholarly journals Performance Analysis and Improvement of Optical Camera Communication

2018 ◽  
Vol 8 (12) ◽  
pp. 2527 ◽  
Author(s):  
Moh. Khalid Hasan ◽  
Mostafa Zaman Chowdhury ◽  
Md. Shahjalal ◽  
Van Thang Nguyen ◽  
Yeong Min Jang
Keyword(s):  
User Satisfaction ◽  
High Performance ◽  
Focal Length ◽  
Sampling Rate ◽  
Image Sensor ◽  
Edge Length ◽  
Data Rate ◽  
Principal Factors ◽  
Communication Distance ◽  
Optical Camera Communication

Optical camera communication (OCC) is a technology in which a camera image sensor is employed to receive data bits sent from a light source. OCC has attracted a lot of research interest in the area of mobile optical wireless communication due to the popularity of smartphones with embedded cameras. Moreover, OCC offers high-performance characteristics, including an excellent signal-to-interference-plus-noise ratio (SINR), high security, low interference, and high stability with respect to varying communication distances. Despite these advantages, OCC suffers from several limitations, the primary of which is the low data rate. In this paper, we provide a comprehensive analysis of the parameters that influence the OCC performance. These parameters include the camera sampling rate, the exposure time, the focal length, the pixel edge length, the transmitter configurations, and the optical flickering rate. In particular, the focus is on enhancing the data rate, SINR, and communication distance, which are the principal factors determining the quality of service experienced by a user. The paper also provides a short survey of modulation schemes used in OCC on the basis of the achieved data rate, communication distance, and possible application scenarios. A theoretical analysis of user satisfaction using OCC is also rendered. Furthermore, we present the simulation results demonstrating OCC performance with respect to variations in the parameters mentioned above, which include the outage probability analysis for OCC.

scholarly journals Design of an SVM Classifier Assisted Intelligent Receiver for Reliable Optical Camera Communication

Sensors ◽  
2021 ◽  
Vol 21 (13) ◽  
pp. 4283
Author(s):  
Md.-Habibur Rahman ◽  
Md. Shahjalal ◽  
Moh. Khalid Hasan ◽  
Md.-Osman Ali ◽  
Yeong-Min Jang
Keyword(s):  
Light Emitting Diode ◽  
Characteristic Curve ◽  
Analysis Data ◽  
Image Sensor ◽  
Data Rate ◽  
Support Vector ◽  
Svm Classifier ◽  
High Data ◽  
Receiver System ◽  
Optical Camera Communication

Embedding optical camera communication (OCC) commercially as a favorable complement of radio-frequency technology has led to the desire for an intelligent receiver system that is eligible to communicate with an accurate light-emitting diode (LED) transmitter. To shed light on this issue, a novel scheme for detecting and recognizing data transmitting LEDs has been elucidated in this paper. Since the optically modulated signal is captured wirelessly by a camera that plays the role of the receiver for the OCC technology, the process to detect LED region and retrieval of exact information from the image sensor is required to be intelligent enough to achieve a low bit error rate (BER) and high data rate to ensure reliable optical communication within limited computational abilities of the most used commercial cameras such as those in smartphones, vehicles, and mobile robots. In the proposed scheme, we have designed an intelligent camera receiver system that is capable of separating accurate data transmitting LED regions removing other unwanted LED regions employing a support vector machine (SVM) classifier along with a convolutional neural network (CNN) in the camera receiver. CNN is used to detect every LED region from the image frame and then essential features are extracted to feed into an SVM classifier for further accurate classification. The receiver operating characteristic curve and other key performance parameters of the classifier have been analyzed broadly to evaluate the performance, justify the assistance of the SVM classifier in recognizing the accurate LED region, and decode data with low BER. To investigate communication performances, BER analysis, data rate, and inter-symbol interference have been elaborately demonstrated for the proposed intelligent receiver. In addition, BER against distance and BER against data rate have also been exhibited to validate the effectiveness of our proposed scheme comparing with only CNN and only SVM classifier based receivers individually. Experimental results have ensured the robustness and applicability of the proposed scheme both in the static and mobile scenarios.

scholarly journals Design and Implementation of the MIMO–COOK Scheme Using an Image Sensor for Long-Range Communication

Sensors ◽  
2020 ◽  
Vol 20 (8) ◽  
pp. 2258 ◽  
Author(s):  
Van Hoa Nguyen ◽  
Minh Duc Thieu ◽  
Huy Nguyen ◽  
Yeong Min Jang
Keyword(s):  
Visible Light ◽  
Radio Frequency ◽  
Human Health ◽  
Error Rate ◽  
Channel Coding ◽  
Matched Filter ◽  
Focal Length ◽  
Satellite Communications ◽  
Image Sensor ◽  
Communication Distance

Radio-frequency technologies are widely applied in many fields such as mobile systems, healthcare systems, television and radio broadcasting, and satellite communications. However, one major problem in wireless communication based on radio frequencies is its impact on human health. High frequencies adversely impact human health more than low frequencies if the signal power transgresses the permissible threshold. Therefore, researchers are investigating the use of visible light waves (instead of the radio-frequency band) for data transmission in three major areas: visible light communication, light fidelity, and optical camera communication. In this paper, we propose a scheme that upgrades the camera on–off keying (COOK) scheme by using it with the multiple-input multiple-output (MIMO) scheme; COOK has been recommended by the IEEE 802.15.7-2018 standard. By applying technologies, such as matched filter, region of interest, and MIMO, our proposed scheme promises to improve the performance of the conventional scheme by improving the data rate, communication distance, and bit error rate. By controlling the exposure time, the focal length in a single camera and using channel coding, our proposed scheme can achieve the communication distance of up to 20 m, with a low error rate.

scholarly journals Energy Saving Schemes for Scalable Mobile Computing Networks

2021 ◽  
Author(s):  
Ali Alnoman
Keyword(s):  
Energy Consumption ◽  
Energy Saving ◽  
User Satisfaction ◽  
Virtual Machines ◽  
Base Station ◽  
Data Rate ◽  
Mobile Users ◽  
Task Completion ◽  
Programming Approach ◽  
Network Scalability

With the growing popularity of smart applications that contain computing-intensive tasks, the provision of radio and computing resources with high quality is becoming more and more challenging. Moreover, supporting network scalability is crucial to accommodate the massive numbers of connected devices. In this thesis, we present effective energy saving strategies that consider the utilization of network elements such as base stations and virtual machines, and implement on/off mechanisms taking into account the quality of service (QoS) required by mobile users. Moreover, we investigate the performance of a NOMA-based resource allocation scheme in the context of Internet of Things aiming to improve network scalability and reduce the energy consumption of mobile users. The system model is mainly built upon the M/M/k queueing system that has been widely used in most relevant works. First, the energy saving mechanism is formulated as a 0-1 knapsack problem where the weight and value of each small base station is determined by the utilization and proportion of computing tasks at that base station, respectively. The problem is then solved using the dynamic programming approach which showed significant energy saving performance while maintaining the cloud response time at desired levels. Afterwards, the energy saving mechanism is applied on edge computing to reduce the amount of under-utilized virtual machines in edge devices. Herein, the square-root staffing rule and the Halfin-Whitt function are used to determine the minimum number of virtual machines required to maintain the queueing probability below a threshold value. On the user level, reducing energy consumption can be achieved by maximizing data rate provision to reduce the task completion time, and hence, the transmission energy. Herein, a NOMA-based scheme is introduced, particularly, the sparse code multiple access (SCMA) technique that allows subcarriers to be shared by multiple users. Not only does SCMA help provide higher data rates but also increase the number of accommodated users. In this context, a power optimization and codebook allocation problems are formulated and solved using the water-filling and heuristic approaches, respectively. Results show that SCMA can significantly improve data rate provision and accommodate more mobile users with improved user satisfaction.

scholarly journals ROA-CONS: Raccoon Optimization for Job Scheduling

Symmetry ◽  
2021 ◽  
Vol 13 (12) ◽  
pp. 2270
Author(s):  
Sina Zangbari Koohi ◽  
Nor Asilah Wati Abdul Hamid ◽  
Mohamed Othman ◽  
Gafurjan Ibragimov
Keyword(s):  
User Satisfaction ◽  
High Performance ◽  
Job Scheduling ◽  
Response Times ◽  
Scheduling Algorithm ◽  
Desktop Computer ◽  
Network Heterogeneity ◽  
Parallel Job Scheduling ◽  
Scheduling Method ◽  
And Performance

High-performance computing comprises thousands of processing powers in order to deliver higher performance computation than a typical desktop computer or workstation in order to solve large problems in science, engineering, or business. The scheduling of these machines has an important impact on their performance. HPC’s job scheduling is intended to develop an operational strategy which utilises resources efficiently and avoids delays. An optimised schedule results in greater efficiency of the parallel machine. In addition, processes and network heterogeneity is another difficulty for the scheduling algorithm. Another problem for parallel job scheduling is user fairness. One of the issues in this field of study is providing a balanced schedule that enhances efficiency and user fairness. ROA-CONS is a new job scheduling method proposed in this paper. It describes a new scheduling approach, which is a combination of an updated conservative backfilling approach further optimised by the raccoon optimisation algorithm. This algorithm also proposes a technique of selection that combines job waiting and response time optimisation with user fairness. It contributes to the development of a symmetrical schedule that increases user satisfaction and performance. In comparison with other well-known job scheduling algorithms, the simulation assesses the effectiveness of the proposed method. The results demonstrate that the proposed strategy offers improved schedules that reduce the overall system’s job waiting and response times.

High-speed, high-precision focal length measurement using double-hole mask and advanced image sensor software

2018 ◽  
Vol 74 ◽  
pp. 239-244
Author(s):  
Binh Xuan Cao ◽  
Phuong Le Hoang ◽  
Sanghoon Ahn ◽  
Jeng-o Kim ◽  
Heeshin Kang ◽  
...  
Keyword(s):  
High Precision ◽  
High Speed ◽  
Focal Length ◽  
Image Sensor ◽  
Length Measurement

scholarly journals Photoplethysmography-Based Continuous Systolic Blood Pressure Estimation Method for Low Processing Power Wearable Devices

2019 ◽  
Vol 9 (11) ◽  
pp. 2236 ◽  
Author(s):  
Rolandas Gircys ◽  
Agnius Liutkevicius ◽  
Egidijus Kazanavicius ◽  
Vita Lesauskaite ◽  
Gyte Damuleviciene ◽  
...  
Keyword(s):  
Blood Pressure ◽  
Systolic Blood Pressure ◽  
High Performance ◽  
Pulse Wave ◽  
Blood Pressure Measurement ◽  
Sampling Rate ◽  
Estimation Method ◽  
Wearable Devices ◽  
Wave Steepness ◽  
Processing Power

Regardless of age, it is always important to detect deviations in long-term blood pressure from normal levels. Continuous monitoring of blood pressure throughout the day is even more important for elderly people with cardiovascular diseases or a high risk of stroke. The traditional cuff-based method for blood pressure measurements is not suitable for continuous real-time applications and is very uncomfortable. To address this problem, continuous blood pressure measurement methods based on photoplethysmogram (PPG) have been developed. However, these methods use specialized high-performance hardware and sensors, which are not available for common users. This paper proposes the continuous systolic blood pressure (SBP) estimation method based on PPG pulse wave steepness for low processing power wearable devices and evaluates its suitability using the commercially available CMS50FW Pulse Oximeter. The SBP estimation is done based on the PPG pulse wave steepness (rising edge angle) because it is highly correlated with systolic blood pressure. The SBP estimation based on this single feature allows us to significantly reduce the amount of data processed and avoid errors, due to PPG pulse wave amplitude changes resulting from physiological or external factors. The experimental evaluation shows that the proposed SBP estimation method allows the use of off-the-shelf wearable PPG measurement devices with a low sampling rate (up to 60 Hz) and low resolution (up to 8-bit) for precise SBP measurements (mean difference MD = −0.043 and standard deviation SD = 6.79). In contrast, the known methods for continuous SBP estimation are based on equipment with a much higher sampling rate and better resolution characteristics.

A Novel Segment-Based Data Transfer Scheme for Low-Power CMOS Surveillance Image Sensors

2017 ◽  
Vol 27 (02) ◽  
pp. 1850027
Author(s):  
Mehdi Habibi ◽  
Khatereh Akbari ◽  
Marzieh Mokhtari ◽  
Peyman Moallem
Keyword(s):  
Data Transfer ◽  
Cmos Technology ◽  
Image Sensor ◽  
Data Rate ◽  
Image Sensors ◽  
Solar Panels ◽  
Transfer Scheme ◽  
Data Rates ◽  
Low Power Cmos ◽  
The Given

Smart image sensors with low data rate output are well fitted for security and surveillance tasks, since at lower data rates, power consumption is reduced and the image sensor can be operated with limited energy resources such as solar panels. In this paper, a new data transfer scheme is presented to reduce the data rate of the pixels which have undergone value change. Although different pixel difference detecting architectures have been previously reported but it is shown that the given method is more effective in terms of power dissipation and data transfer rate reduction. The proposed architecture is evaluated as a [Formula: see text]-pixel sensor in a standard CMOS technology and comparison with other data transfer approaches is performed in the same process and configuration.

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