Cross-layer hybrid automatic repeat request error control with turbo processing for wireless system

The increasing demand for wireless communication system requires an efficient design in wireless communication system. One of the main challenges is to design error control mechanism in noisy wireless channel. Forward Error Correction (FEC) and Automatic Repeat reQuest (ARQ) are two main error control mechanisms. Hybrid ARQ allows the use of either FEC or ARQ when required. The issues with existing Hybrid ARQ are reliability, complexity and inefficient design. Therefore, the design of Hybrid ARQ needs to be further improved in order to achieve performance close to the Shannon capacity. The objective of this research is to develop a Cross-Layer Design Hybrid ARQ defined as CLD_ARQ to further minimize error in wireless communication system. CLD_ARQ comprises of three main stages. First, a low complexity FEC defined as IRC_FEC for error detection and correction has been developed by using Irregular Repetition Code (IRC) with Turbo processing. The second stage is the enhancement of IRC_FEC defined as EM_IRC_FEC to improve the reliability of error detection by adopting extended mapping. The last stage is the development of efficient CLD_ARQ to include retransmission for error correction that exploits EM_IRC_FEC and ARQ. In the proposed design, serial iterative decoding and parallel iterative decoding are deployed in the error detection and correction. The performance of the CLD_ARQ is evaluated in the Additive White Gaussian Noise (AWGN) channel using EXtrinsic Information Transfer (EXIT) chart, bit error rate (BER) and throughput analysis. The results show significant Signal-to-Noise Ratio (SNR) gain from the theoretical limit at BER of 10-5. IRC_FEC outperforms Recursive Systematic Convolutional Code (RSCC) by SNR gain up to 7% due to the use of IRC as a simple channel coding code. The usage of CLD_ARQ enhances the SNR gain by 53% compared to without ARQ due to feedback for retransmission. The adoption of extended mapping in the CLD_ARQ improves the SNR gain up to 50% due to error detection enhancement. In general, the proposed CLD_ARQ can achieve low BER and close to the Shannon‘s capacity even in worse channel condition

Hybrid ARQ type I based on convolutional code

Hybrid Automatic Repeat reQuest (HARQ), error control scheme based on a convolutional code for packet transmission over wireless channels was proposed. The analysis of the throughput and bit-error rate (BER) performance, according to the different constraint lengths (K=3 and K=4) and code rate (1/2 and 1/3) of convolutional codes on HARQ type I simulation scheme are presented. Certain error correction capability is provided in each (re)transmitted packet, and the information can be recovered from each transmission or retransmission alone if the errors are within the error correction capability. Simulation of HARQ is limited up to three retransmissions for each SNR in several iterations

Derivative Proportional – Integral Controller Using Nelder-Mead Optimization for Glycerine Purification Heating Process

It is important to purify the crude glycerine before to convert them into value-added products. Such dark colored crude have high free fatty acid content that can be removed via heating process. This paper focuses mainly on the heating control system, which has contributed to the improvement of the glycerine purification process system. The design of Derivative Proportional – Integral controller for the glycerine temperature control loop system could demonstrate some improvement of the glycerine heating process control response in term of process settling time and percent overshoot. Derivative Proportional – Integral is a proposed controller where Proportional and Derivative control actions operate on process variables rather than error signals. Meanwhile, the integral mode is connected to the forward path where the error signal is used as an input to the control mode. The output of the two control modes is then subtracted to drive the process. The Derivative Proportional – Integral controller was designed using the Nelder-Mead optimization algorithm with objective function of the Integral Time Absolute Error criteria calculated using Simpson's one-third rule. The control performance of the proposed controller was analyzed by comparing the rise time, percent overshoot and settling time of the response with that of the conventional PID controller. The simulation results show that the Nelder-Mead optimization algorithm can be used and can produce a good control system with zero percent overshoot and shorter heating time compared to the achievements of the PID control system. In addition, the robustness test of the controller has shown that the proposed control system can effectively detect changes in the operating temperature. The control performance shown by the proposed controller is excellent. The Derivative Proportional – Integral control system designed based on optimization algorithm techniques can improve the performance of the glycerine purification process heating system to meet the purified glycerine requirements

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

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

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

Development of an integrated web-based indoor parking system with sensors

Growing number of vehicles in recent years has an impact to road capacity and parking spaces. Even with support of an efficient public transport, some users prefer to use their personal vehicles. Hence, it resulted in lack of parking space in public areas. Looking for parking spaces is time, money and fuel consuming and causes unnecessary stress to drivers. This work will design and develop the sensing infrastructure which will be used as a part of an integrated smart parking system that integrates the sensing capability with wireless transmission to the central web portal. Then, the central web portal will provide a platform for vehicle parking reservation system made online through a computer. This system also permits drivers to make a reservation on available parking slots utilizing ID code keyed in for authentication and several indicators to denote availability, non-availability and reservation status at the parking slot. The communication technologies used has to upload and download information to and from the web. This work has shown that the development was successful for a single floor parking system and can be upgraded to multi-storey parking complex

Statistical feature analysis of EEG signals for calmness index establishment

Electroencephalographic (EEG) signals are very closely related to psychophysiological. The EEG signals displayed few responses which can be categorized. This article discussed the use of statistics over the EEG features which confirm the different mental characteristics. Two different type of stimulus was given named as relaxed state and non-relaxed state. Asymmetry index was computed as the EEG features via the alpha waves and was extracted during the relaxed state and the non-relaxed state. The EEG features were clustered to a group of three, four and five using Fuzzy C-Means. During the relaxed state, the alpha wave showed a higher response as compared to the non-relaxed state. This is observed by using the mean relative energy between the relaxed state and non-relaxed state. To ensure which EEG features in the clusters showed a significant difference, p < .05, a statistical test was used. Wilcoxon Signed Ranks test is the best-statistical test to verify the selected clusters as it is suitable to analyze the small sample of data. Wilcoxon Signed Ranks test used a hypothesis testing which using the same method as paired sample t-test. The advantage in using Wilcoxon Signed Ranks test is that, it uses the median to get the difference between two samples of data. Analytical results showed that the data features of four clusters and three clusters give a significant difference, thus the obtained results can be used to further up the study. The Wilcoxon Signed Ranks test results confirmed that the proposed technique has potential in establishing the calmness index

Fabrication of Human Body Phantom for Body Centric Communication Systems at 2.4 GHz

This research is intending to investigate the human skin phantom’s dielectric constant. The phantom will be used to test the electromagnetic compatibility later on since it can be harmful if it is directly tested on real human body. The human body phantom is made to have similar property as a skin tissue, at the operating frequency of 2.4 GHz. A methodology of the process is discussed. The phantom is fabricated, tested and measured. A fabricated phantom with the desired permittivity of εr and conductivity of σ values; are controlled by the amount of polyethylene powder and sodium chloride. The information on dielectric constant of the phantom based on measured values of εr and σ will be determined. The factors in making a good phantom is discussed. A good level of agreement is observed between simulation and measurement results

Agricultural Production System Based On IOT

Internet of things (IoT) is not a single word, but it has gathered billions of devices in the same lane. The Internet of things has given the lives of things. Machines have a sense now like a human. It works remotely as the program has been settled inside the chip. The system has become so smart and reliable. The Internet of things has brought out changes in most of the sectors of humankind. Meanwhile, agriculture is the main strength of a country. The more the production of agricultural products increased, the world will be more completeness from food shortage. The production of agriculture can be increased when the IoT system can be entirely implemented in the agricultural sector. Most of the approaches for IoT based agriculture have been reviewed in this paper. Related to IoT based agriculture, most of the architecture and methodology have been interpreted and have been critically analyzed based on previous related work of the researchers. This paper will be able to provide a complete idea with the architecture and methodology in the field of IoT based agriculture. Moreover, the challenges for agricultural IoT are discussed with the methods provided by the researche