Exploiting 2-Dimensional Source Correlation in Channel Decoding with Parameter Estimation

Traditionally, it is assumed that source coding is perfect and therefore, the redundancy of the source encoded bit-stream is zero. However, in reality, this is not the case as the existing source encoders are imperfect and yield residual redundancy at the output. The residual redundancy can be exploited by using Joint Source Channel Coding (JSCC) with Markov chain as the source. In several studies, the statistical knowledge of the sources has been assumed to be perfectly available at the receiver. Although the result was better in terms of the BER performance, practically, the source correlation knowledge were not always available at the receiver and thus, this could affect the reliability of the outcome. The source correlation on all rows and columns of the 2D sources were well exploited by using a modified Bahl-Cocke-Jelinek-Raviv (BCJR) algorithm in the decoder. A parameter estimation technique was used jointly with the decoder to estimate the source correlation knowledge. Hence, this research aims to investigate the parameter estimation for 2D JSCC system which reflects a practical scenario where the source correlation knowledge are not always available. We compare the performance of the proposed joint decoding and estimation technique with the ideal 2D JSCC system with perfect knowledge of the source correlation knowledge. Simulation results reveal that our proposed coding scheme performs very close to the ideal 2D JSCC system

Joint Source Channel Decoding Exploiting 2D Source Correlation with Parameter Estimation for Image Transmission over Rayleigh Fading Channels

This  paper  investigates  the  performance  of  a  2- Dimensional  (2D)  Joint  Source  Channel  Coding  (JSCC)  system assisted  with  parameter  estimation  for  2D  image  transmission over  an  Additive  White  Gaussian  Noise  (AWGN)  channel  and a  Rayleigh  fading  channel.  Baum-Welsh  Algorithm  (BWA)  is employed  in  the  proposed  2D  JSCC  system  to  estimate  the source correlation statistics during channel decoding. The source correlation is then exploited during channel decoding using a Modified Bahl-Cocke-Jelinek-Raviv (BCJR) algorithm. The performance of the 2D JSCC system with the BWA-based parameter estimation technique (2D-JSCC-PET1) is evaluated via image transmission simulations.  Two  images,  each  exhibits  strong  and weak  source  correlation  are  considered  in  the  evaluation  by measuring the Peak Signal Noise Ratio of the decoded images at the  receiver.  The proposed 2D-JSCC-PET1 system is compared with various benchmark systems. Simulation results reveal that the 2D-JSCC-PET1 system outperforms the other benchmark systems (performance gain of 4.23 dB over the 2D-JSCC-PET2 system and 6.10 dB over the 2D JSCC system).  The proposed system also can perform very close to the ideal 2D JSCC system relying on the assumption of perfect source correlation knowledge at the receiver that shown only 0.88 dB difference in performance gain

A Review of Power Domain Non-Orthogonal Multiple Access in 5G Networks

This paper highlights the fundamentals of the strong candidate Power Domain Non-Orthogonal Multiple Access (PD-NOMA) technique, and how it can best fit the requirements of fifth Generation (5G) in practical applications. PD-NOMA ensures flexibility in radio resource to improve user’s access performance. Multiple users share the same radio resources in PD-NOMA, and therefore better spectrum efficiency can be achieved. The practical system design aspects of PD-NOMA are considered in this paper by exploring different network scenarios. Optimal performances of PD-NOMA system can be obtained by suitable power allocation schemes, with reduce the computational complexity, and advanced user pairing strategy. Theoretical formulation and solutions are also explained prior to the concept of downlink PD-NOMA. Challenges and future research windows are discussed before conclusion of this paper

Human-computer interaction in mobile learning: a review

Mobile learning mainly concerns mobility and high-quality education, regardless of location or time. Humancomputer interaction comprises the concepts and methods in which humans interact with computers, including designing, implementing, and evaluating computer systems that are accessible and provide an intuitive user interface. Some studies showed that mobile learning could help overcome multiple limitations and improve learning in educational systems. The study investigates the HCI design challenges, including the guidelines and methods in mobile HCI for education. An existing mobile learning tool was discussed on the current and future design enhancements of Udemy. Next is the further discussion on future mobile learning to provide the possible improvements for learners based on the challenges of mobile HCI in education

PAPR reduction techniques in generalized inverse discrete fourier transform non-orthogonal frequency division multiplexing system

A promising system of Generalized Inverse Discrete Fourier Transform Non-Orthogonal Frequency Division Multiplexing (GIDFT n-OFDM) system can fulfil the requirement of supporting higher data rate in Fifth Generation (5G) technology. However, this system experience High Peak to Average Power Ratio (PAPR) due to massive number of subcarriers signal is transmitted. In this paper, three types of usual PAPR reduction techniques were applied in GIDFT n-OFDM system which are Clipping, Partial transmit Transform (PTS) and Selective Mapping (SLM). The system performance is compared and evaluated using Complementary Cumulative Distribution Function (CCDF) plot. Simulation results show that SLM technique give significant reduction of PAPR 9 dB of the original performance

A review of vibration detection methods using accelerometer sensors for water pipeline leakage

Water pipeline leakage detection is still an important issue, particularly for the development of smart cities. Thus, this paper reviews water pipeline leakage detection techniques, which can be classified into three different categories, namely software-based, hardware-based and conventional methods. We compare the advantages and disadvantage for all methods in the groups and thoroughly discuss the hardware-based method, which is our focus. Specifications on water pipeline testbeds used in previous works are also highlighted. Since many recent techniques are based on accelerometer or vibration sensors, a comparative study that includes the cost and accuracy in identifying the pipeline leaks is presented. The theoretical computation of the vibration induced from our water pipeline testbed is also demonstrated and compared with the actual vibration data collected from experimental works using three different sensors, namely, MPU6050, MMA7361 and ADXL335

Investigation of human electromagnetic radiation characteristic for kidney disease patients

The human body is shown to have their own radiation that emits at certain frequencies into the space surround the body. The purpose of this paper is to investigate the characteristic of human electromagnetic radiation among kidney disease patients and non-kidney disease participants. The body radiation frequencies are measured using body radiation wave detector at twenty-two points of the human body. The properties of human electromagnetic radiation are evaluated using statistical analysis of dependent t-test of Wilcoxon Signed Rank test and independent t-test of Mann-Whitney U test. Significant results with the Sig. value below 0.05 are shown in lower body, torso, chakra, arm and upper body, thus indicates the characteristic differences of human electromagnetic radiation frequency between kidney disease patients and non-kidney disease participants

Feasibility Study of a Low Cost Saltwater Lamp for Rural Area

Renewable energy is energy generated from natural resources and cannot be depleted. Solar energy is the fastest growing source of renewable energy but the high installation and maintenance cost of a solar system has restrained the consumers from adopting this technology at their home or commercial building. This is especially true for those in developing countries. A new promising renewable energy source known as saltwater energy that takes advantage of the conductive nature of salt water to generate electricity, has intrigued many people. A study has been conducted to develop and produce saltwater-powered devices especially for rural and remote communities in Malaysia as well as worldwide. To main objective of this study is to determine the factors that affect the performance of the saltwater energy generation such as electrode’s combinations, number of cells and the durability of the electrodes. It was found that the choice of electrodes as anode and cathode does affect the voltage output. However, due to the small power produce, the number of cells must be increased to produce enough power to light up a led light and to provide power to USB port. This paper also conducted a cost analysis of using the saltwater lamp and compared it with a solar system. Although the difference in the cost per hour is very small, there are a number of disadvantages of solar system that need to be aware of. The findings obtained from these experiments will be used to design a prototype of the illumination technology for further product development

Risk assessment on electrical maintenance activity at Menora Tunnel, Perak

Risk assessment is an essential element for Occupational Safety and Health. Risk assessment allows an organization to assess and control the potential risks to a minimum so as not to impact or causes major accident to workers and organizations. Every maintenance activities in industries such as construction, manufacturing, agriculture or in other sector should ensure that risk assessment is carried out and all the inherent risks are well controlled. For example, electrical maintenance work in a highway tunnel is also necessary to ensure that the inherent risks are eliminated or controlled to a minimum during the work carried out. This study is to identify potential risks that could occur during electrical maintenance activities in highway tunnels. The objective of the study is to assess the risk faced by the staff during electrical maintenance activity and to recommend the action plans to manage the critical risk which can lead to fatalities during electrical maintenance activity. The risk will be identified and assess based on bowtie analysis method and the measurement of risk level will be referred to five levels of risk-matrix. The development of bowtie diagram will be using a fault tree together with an event tree and barriers to mapping the risk

Exploitation of 2D binary source correlation using turbo block codes with fine-tuning

This article proposes a joint source-channel coding technique for two-dimensional (2D) binary Markov sources by using concatenated turbo block codes composed of two Bose, Chaudhuri, Hocquenghem (BCH) codes, of which output is followed by a rate-1 recursive systematic convolutional code. The source correlation of all rows and columns of the 2D source is well exploited by using a modified Bahl-Cocke-Jelinek-Raviv (BCJR) algorithm for the decoding of the BCH codes. Simulation results show that the proposed technique outperforms in terms of bit error rate the codes that exploits one-dimensional (1D) source correlation using the modified BCJR algorithm, and obviously the conventional system without source correlation exploitation. In order to further improve the performance, this article aims to make fine-tuning of the code parameters, given the source correlation property, that can achieve performance even closer to the theoretical limit than without the fine-tuning. Finally, results of image transmission simulations using two images, one having strong and the other weak 2D correlation, are presented to demonstrate the effectiveness of our proposed techniqu