13 research outputs found
Performance Analysis and Modeling of MIMO Systems
In this paper, various channel estimation, interpolation and
equalization techniques used in the analysis of MIMO
configurations or formats are compared and the technique
with the optimum performance determined. The channel
estimation of these configurations were determined by
modelling and simulating them in a wireless environment
using MATLAB software. The figure of Merits used are the
BER and MSE as a function of the SNR. The study revealed
that MIMO is a more energy efficient technique since it
achieved a good BER performance at lower transmit SNR,
when compared to the MISO and SISO which requires higher
SNR to achieve at same BER performance. This is as a result
of the diversity and multiplexing gain experienced in the
multiple antenna techniques using the STB
Comparative Analysis of Channel Estimation Techniques in SISO, MISO and MIMO Systems
Abstract—The ever-growing need for high data rate, bandwidth
efficiency, reliability, less complexity and less power
consumption in our communication systems is on the increase.
Modern techniques have to be developed and put in place to meet
these requirements. Research has shown, that compared to conventional
Single Input Single Output (SISO) systems, Multiple-
Input Single Output (MISO), and Multiple-Input Multiple-
Output (MIMO) can actually increase the data rate of a communication
system, without actually requiring more transmit power
or bandwidth. This paper aims at the investigation of the existing
channel estimation techniques. Based on the pilot arrangement,
the block type and comb type are compared, employing the
Least Square estimation (L.S) and Minimum Mean Squared
Error (MMSE) estimators. Pilots occupy bandwidth, minimizing
the number of pilots used to estimate the channel, in order
to allow for more bandwidth utilization for data transmission,
without compromising the accuracy of the estimates is taken
into consideration. Various channel interpolation techniques and
pilot-data insertion ratio are investigated, simulated and compared,
to determine the best performance technique with less
complexity and minimum power consumption. As performance
measures, the Mean Squared Error (MSE) and Bit Error Rate
(BER) as a function of Signal to Noise power Ratio (SNR) of
the different channel estimation techniques are plotted, in order
to identify the technique with the most optimal performance.
The complexity and energy efficiency of the techniques are also
investigated. The system modelling and simulations are carried
out using Matlab simulation package. The MIMO gives the
optimum performance, followed by the MISO and SISO. This
is as a result of the diversity and multiplexing gain experienced
in the multiple antenna techniques using the STBC
Development of Smart Plate Number Recognition System for Fast Cars with Web Application
Traffic law violation has been recognized as a major cause for road accidents in most parts of the world with majority occurring in developing countries. Even with the presence of rules and regulations stipulated against this, violators are still on the increase. This is due to the fact that the rules are not properly enforced by appropriate authorities in those parts of the world. Therefore, a system needs to be designed to assist law enforcement agencies to impose these rules to improve road safety and reduce road accidents. This work uses a Vehicle Plate Number Recognition (VNPR) system which is a real-time embedded system to automatically recognize license plate numbers. It provides an alternative means to VPNR using an open-source library known as openCV. The main aim of the system is to use image processing to identify vehicles violating traffic by their plate numbers. It consists of an IR sensor for detecting the vehicle. During testing, a minimum time was set for the sensor to detect the object which was recorded by the microprocessor. Once it was less than the set time, the camera was triggered to capture the plate number and store the image on the Raspberry Pi. The image captured is processed by the Raspberry Pi to extract the numbers on the image. The numbers on the capture imaged were viewed on a web page via an IP address. The system if implemented can be used to improve road safety and control traffic of emerging smart cities. It will also be used to apply appropriate sanctions for traffic law violators
Wireless power transfer: a review
The ubiquitous nature and the proliferation of mobile devices has made wireless power transfer (WPT) a very important area of research. The flexibility and cost effectiveness of charging these enormous devices in our world without having to connect physically to any electrical port especially when the user is indisposed to do so is a very attractive characteristic of WPT. Conventional means of charging the batteries of these mobile devices are wired which invariably meansthey requirephysical connection to power sources through electrical cables. Electric power istransmitted wirelessly when a magnetic field produced by the inductive coupling of coils or electrical field produced by the capacitive coupling between electrodes is transferred over a short distance through the air interface and later received by an antenna for utilisation. This article gives a detailed review of the existing wireless power transfer technologies, principles of operation, applications and the opportunities for future research in this area of emerging technology. However, WPT has some drawbacks but it is a disruptive technology with the ability to revolutionise the dynamics of mobile wireless systems, internet of things and otherallied future technologies
Design and analysis of a broadband microwave amplifier
This paper presents the procedures involved in the design and analysis of a microstrip broadband microwave amplifier. For system design, simulation, optimization and analysis, a Computer Aided Design (CAD) tool known as Agilent Advanced Design System (ADS) was employed. The amplifier device-FLC317MG-4 FET, was tested for stability, and was observed to be unconditionally stable between 2 to 6 GHz frequency band. Two possible ideal matching circuits were investigated to identify the best matching circuit with the maximum transducer power gain. It was observed that the quarter-wave transformer with parallel open circuit stub, gave a high gain at a wider range of frequency (larger bandwidth/ broadband), than the other matching circuit. Hence, it was employed for the broadband amplifier design using microstrips, and achieved a maximum flat gain of about 9.8 dB to 10.118 dB, at a bandwidth of 3.5 to 4.5 GHz
Performance of MPLS-based Virtual Private Networks and Classic Virtual Private Networks Using Advanced Metrics RECOGNITION TECHNOLOGY
Multiprotocol Label Switching (MPLS) is effective in managing and utilizing available network bandwidth. It has advanced security features and a lower time delay. The existing literature has covered the performance of MPLS-based networks in relation to conventional Internet Protocol (IP) networks. But, too few literatures exist on the performance of MPLS-based Virtual Private Networks (VPN) in relation to traditional VPN networks. In this paper, a comparison is made between the effectiveness of the MPLS-
VPN network and a classic VPN network using simulation studies done on OPNET® The performance metrics used to carry out the comparison include; End to End Delay, Voice Packet Sent/Received and Label Switched Path’s Traffic. The simulation study was carried out with Voice over Internet Protocol (VoIP) as the test bed. The result of the study showed that MPLS-based VPN networks outperform classic
VPN networks
Design and simulation of a novel 3-point star rectifying antenna for RF energy harvesting at 2.4 GHz
The rectenna as a device, is critical for achieving long-distance wireless power
transfer. The centrality of this study is focused on adding to the collective knowledge of
the subject matter, by providing a new perspective in terms of an alternative design for
the antenna component of the rectenna. Essentially, this study features a novel “3-point
star” design which was simulated in comparison with the conventional square microstrip
patch antenna design. Both designs (i.e., operating at the Wi-Fi band 2.4 GHz), were
assessed in terms of simulated performance parameters: gain, directivity, return loss,
radiation pattern, and efficiency. From the simulation results, the proposed “3-point star”
design, though slightly less efficient exhibited improved performance over the conventional
square patch alternative, in terms of gain, directivity, and return loss. For the
rectifying component, a greinacher voltage-doubler (with two HSMS2820 diodes), was
designed separately and simulated over a range of input power levels (10dBm—34dBm),
for 220-Ω, 380-Ω and 810-Ω load resistances, respectively. A maximum conversion
efficiency of 88.02% was achieved at 28dBm for an 810 Ω load resistance. All design
simulations were executed using Advanced Design System (ADS) software
Performance of MPLS-based virtual private networks and classic virtual private networks using advanced metrics
Multiprotocol Label Switching (MPLS) is effective in managing and utilizing available network bandwidth. It has advanced security features and a lower time delay. The existing literature has covered the performance of MPLS-based networks in relation to conventional Internet Protocol (IP) networks. But, too few literatures exist on the performance of MPLS-based Virtual Private Networks (VPN) in relation to traditional VPN networks. In this paper, a comparison is made between the effectiveness of the MPLS-VPN network and a classic VPN network using simulation studies done on OPNET®. The performance metrics used to carry out the comparison include; End to End Delay, Voice Packet Sent/Received and Label Switched Path's Traffic. The simulation study was carried out with Voice over Internet Protocol (VoIP) as the test bed. The result of the study showed that MPLS-based VPN networks outperform classic VPN networks
Evaluation of the quality of an image encrytion scheme
Encryption systems have been developed for image viewing applications using the Hill Cipher algorithm. This study aims to evaluate the image encryption quality of the Hill Cipher algorithm. Several traditional metrics are used to evaluate the quality of the encryption scheme. Three of such metrics have been selected for this study. These include, the Colour Histogram, the Maximum Deviation (comparing the original image) and the Entropy Analysis of the encrypted image. Encryption quality results from all three schemes using a variety of images show that a plain Hill Cipher approach gives a good result for all kinds of images but is more suited for colour dense images