K.J.Silva Lorraine - Academia.edu (original) (raw)

Papers by K.J.Silva Lorraine

IOSR Journal of Electronics and Communication Engineering, 2016

Procedia Engineering, 2012

Abstract The Sense Amplifier-based Pass Transistor Logic (SAPTL) is a low energy alternative logi... more Abstract The Sense Amplifier-based Pass Transistor Logic (SAPTL) is a low energy alternative logic topology to fully complementary static CMOS logic. This circuit topology allows the reduction of energy per operation via voltage scaling even in the presence of leakage energy. As the sense amplifier is an essential circuit in designing memory chips, this paper focuses the diagnosis of faults of a sense amplifier used in SAPTL circuit. For that, a particular fault model called stuck-at fault has been introduced. The advantage of the proposed approach is its ability to distinguish between the stuck at Logical ‘1’, ‘0’ and ‘x’. Also, the design and simulation result of a sense amplifier based pass transistor circuit topology has been presented. Then, the results are compared with the stack circuit simulation results using bar graphs.

Abstract-In this paper we proposes a new methodology called as "Antenna Management" , w... more Abstract-In this paper we proposes a new methodology called as "Antenna Management" , which provides a high degree of efficient use of power and power management in high speed wireless networks and high data rate mobile wireless systems. This technique is particularly very usefully in the case of MIMO network interfaces, which contains a number of components and as well as RF chains. The objective of this project is to efficiently manage the available power among the large number of antennas in MIMO systems, and also satisfies all the requirements of MIMO like bit error rate, data rate, minimize energy per bit etc..In this paper we provide a systematic procedure to validate the energy efficiency and benefits of proposed method i.e. Antenna Management. Finally using this paper we provide a great solution for Power requirements by efficiently and effectively managing the all active antennas in MIMO systems.

DOI: 10.5281/zenodo.59669 ABSTRACT With the ever increasing growth of multimedia applications,sec... more DOI: 10.5281/zenodo.59669 ABSTRACT With the ever increasing growth of multimedia applications,security is an important issue in communication and storage of images. Encryption is one of the ways to ensure security.Image encryption techniques try to convert original image to another image that is hard to understand. There are various techniques which are discovered from time to time to ecrypt the images to make images more secure like Key Generation using Genetic algorithm,Secure force algorithm,Block based transformation algorithm etc. In this paper,a low complexity symmetric cryptographic algorithm denoted as Secure Force With Affine Transform has been proposed. The encryption part can be implemented by using simple architecture that only consists of basic mathematical operations (AND, OR,XOR,XNOR,SHIFTING,SWAPPING).This can help to reduce the burden on encoder,because the more complex key expansion process is only carried out at the decoder. The objective of this paper is to perfo...

Pseudolite based positioning is designed to be used as an alternative to GPS when receiver faces ... more Pseudolite based positioning is designed to be used as an alternative to GPS when receiver faces low position accuracy in areas where the satellite signals are less available or non-existent.. However, one of the major problems faced by the pseudolite based navigation system is “Multipath” effect. It is mainly caused by reflections of the signal from the ground or near-by building or other obstacles which limits the effective range of truthful positioning. In this paper, design of Inset-fed ceramic patch array antenna using HFSS has been proposed to overcome the problem. Simulation results present the influence of increase in element number and influence of inter-element spacing on the design. Also, radiation patterns for rectangular and elliptical patch array antenna using different feeds are simulated, presented and comparatively analyzed in this paper.

Digital images are mostly used to protect confidential & important information. But the problem i... more Digital images are mostly used to protect confidential & important information. But the problem is providing authentication and integrity to these digital images is a very challenging task. Therefore using this paper a new efficient authentication method is proposed to provide for grayscale document images using the Portable Network Graphics (PNG) image with verification and data self repair capability. In this concept an authentication signal generated by each block of a grayscale document image and then using Shamir secret sharing scheme grayscale document image authentication signal and binarized block content is combined and transformed into several shares. These several binarized block content shares are then combined into an alpha channel plane then the PNG image is built from combining the grayscale image with alpha channel plan. the authentication signal measured from the current block content does not match that extracted from the shares embedded in the alpha channel plane ...

GPS is the most widely used technology for finding accurate position. However accuracy, availabil... more GPS is the most widely used technology for finding accurate position. However accuracy, availability, and continuity of service for certain high precision applications cannot be met by Global Positioning System (GPS) alone. The GPS like signal transmitted by Pseudolite (PLs) can be employed to augment and provide continuity, accuracy and availability in such environment. The major problems associated with such navigation system are the “Near-Far” and “Multipath problem”. Among various methods of mitigating the near-far problem, pulsing of transmitting PL signal for fractions of a full duty cycle and for mitigating multipath effect, adaptive filter such as Least Mean Square (LMS) has been observed to be more effective. In this paper, the degradation of SNR as the user moves away from PL is presented. The effective dynamic range for a typical receiver incase of CW and varying duty cycle signals from a pulsed PL is estimated and graphically presented. Also, the signal degradation with ...

In this paper we proposes a new methodology called as “Antenna Management” , which provides a hig... more In this paper we proposes a new methodology called as “Antenna Management” , which provides a high degree of efficient use of power and power management in high speed wireless networks and high data rate mobile wireless systems. This technique is particularly very usefully in the case of MIMO network interfaces, which contains a number of components and as well as RF chains. The objective of this project is to efficiently manage the available power among the large number of antennas in MIMO systems, and also satisfies all the requirements of MIMO like bit error rate, data rate, minimize energy per bit etc..In this paper we provide a systematic procedure to validate the energy efficiency and benefits of proposed method i.e. Antenna Management. Finally using this paper we provide a great solution for Power requirements by efficiently and effectively managing the all active antennas in MIMO systems. Key Terms—Power management, MIMO, Antenna management, Energy per Bit

Global Navigation Satellite Systems (GNSS) such as Global Positioning System (GPS), GALILEO and G... more Global Navigation Satellite Systems (GNSS) such as Global Positioning System (GPS), GALILEO and GLONASS need atleast four satellite signals to find out the accurate position. But in some areas, due to the non-availability or blockage of the signals, GNSS alone doesn’t provide the accurate position of the object. Pseudolites (PLs) are ground based transmitters which provide GPS like signals that augment GNSS constellations to enhance the accuracy, integrity, continuity and availability. However, Near-Far effect which reduces the service area is one of the major problems where pseudolites are used. In order to account for such a problem, a step-by-step power control technique has been proposed to enlarge the service area. Simulation results show that the PL with step-by-step power control outperforms much better than conventional PL. The service area using proposed PL resulted in 4 times wider service area than conventional PL. Also, coverage and outage probability are analytically ob...

In this paper we proposes a new methodology called as "Antenna Management" , which provides a hig... more In this paper we proposes a new methodology called as "Antenna Management" , which provides a high degree of efficient use of power and power management in high speed wireless networks and high data rate mobile wireless systems. This technique is particularly very usefully in the case of MIMO network interfaces, which contains a number of components and as well as RF chains. The objective of this project is to efficiently manage the available power among the large number of antennas in MIMO systems, and also satisfies all the requirements of MIMO like bit error rate, data rate, minimize energy per bit etc..In this paper we provide a systematic procedure to validate the energy efficiency and benefits of proposed method i.e. Antenna Management. Finally using this paper we provide a great solution for Power requirements by efficiently and effectively managing the all active antennas in MIMO systems.

In the cellular environment, there will be channel reuse and therefore co-channel interference fr... more In the cellular environment, there will be channel reuse and therefore co-channel interference from other cells exists and as a result the performance will be degraded. So it is necessary to reject the co-channel interference. In this paper, co-channel interference (CCI) cancellation scheme for cooperative communication systems in wireless communication network has been proposed. In the multipath environment, CCI causes more performance degradation in wireless network. Several interference signal mitigation methods have been proposed including Maximum Likelihood (ML), Zero Forcing (ZF), MMSE and Successive Interference Cancellation (SIC). Of all these techniques, MMSE SIC with optimal ordering will reject CCI efficiently and offers performance improvement compared with conventional SIC. In this paper, the overall system performance has been demonstrated in terms of bit error rate (BER) by considering Rayleigh fading channel.

The world's most popular GNSS system is Global Positioning System (GPS). This was developed by th... more The world's most popular GNSS system is Global Positioning System (GPS). This was developed by the U.S Department of Defense (DOD) to know the accurate position coordinates of a location. However, GPS also failed to find the position coordinates especially in dense areas and urban canyon. This situation was eliminated by using ground based satellites called as Pseudolites (PLs) which provide GPS like signals where the obstruction of satellites signals from the GPS constellation take place. Thus, by augmenting the GNSS with Pseudolites the continuity, accuracy and availability were improved. Even though the Pseudolites are useful, still the performance of Pseudolite is limited by the"Near-Far Effect". The various techniques used to overcome near-far Effect are spreading PRN codes, frequency offset, frequency hopping, signal pulsing and Successive Interference Cancellation (SIC). The best way to reduce near-far effect is to use signal pulsing.However, when multiple PLs are employed, multiple access interference limits the system performance. In this paper, the analysis of near-far problem using pulsing scheme has be done while taking GPS constellation into account. Also, the performance evaluation of the PL system with Reference based Successive Interference Cancellation (RSIC) receiver, which is the best optimal method of Multiuser detector (MUD) has been presented.

With the ever increasing growth of multimedia applications,security is an important issue in comm... more With the ever increasing growth of multimedia applications,security is an important issue in communication and storage of images. Encryption is one of the ways to ensure security.Image encryption techniques try to convert original image to another image that is hard to understand. There are various techniques which are discovered from time to time to ecrypt the images to make images more secure like Key Generation using Genetic algorithm,Secure force algorithm,Block based transformation algorithm etc. In this paper,a low complexity symmetric cryptographic algorithm denoted as Secure Force With Affine Transform has been proposed. The encryption part can be implemented by using simple architecture that only consists of basic mathematical operations (AND, OR,XOR,XNOR,SHIFTING,SWAPPING).This can help to reduce the burden on encoder,because the more complex key expansion process is only carried out at the decoder. The objective of this paper is to perform security analysis and performance evaluation of the proposed algorithm. Results of the proposed algorithm have been tested upon different kinds of images and comparitive analysis with other techniques has been presented.

Image Edge detection significantly reduces the amount of data and filters out useless information... more Image Edge detection significantly reduces the amount of data and filters out useless information, while preserving the important structural properties in an image. Since edge detection is in the forefront of image processing for object detection, it is crucial to have a good understanding of edge detection algorithms. In this paper, the comparative analysis of various Image Edge Detection techniques has been presented. It has been shown that the canny edge detection algorithm performs better than all these algorithms under almost all scenarios. However, it has been observed that under noisy conditions Sobel algorithm detect edges more clearly when compared to Canny. It has been also observed that Canny edge detection algorithm is computationally more expensive compared to Sobel, Prewitt and Robert's algorithms. Cancer is a disease characterized by uncontrolled growth of abnormal cells. Hence, it is necessary to detect the edges of cancer cells so that they can be easily subjected to radiation therapy without affecting the other blood cells. So, in this paper Sobel & Canny algorithms have been used to detect the boundaries of cancer cells. Sobel algorithm has detected the edges of cancer cells more clearly compared to Canny algorithm.

Improved Impulse noise Detector (IID) for Adaptive Switching Median (ASWM) filter is presented. T... more Improved Impulse noise Detector (IID) for Adaptive Switching Median (ASWM) filter is presented. The idea behind the improved impulse noise detection scheme is based on normalized absolute difference with in the filtering window, and then removing the detected impulse noise in corrupted images by using ASWM filter. This detection scheme distinguishes the noisy and noise-free pixels efficiently. A weighted median filter, based on standard deviation within the filtering window is used in ASWM filtering. The application of absolute difference, will distinguishes the difference between a noise free and noisy pixel more precisely. The proposed scheme results in efficient detection of noisy pixels. Extensive simulation results show that the proposed scheme significantly outperforms in terms of PSNR and MAE than many other variant types of median filter for random-valued impulse noise. More over IID scheme provides better noise detection performance.

As GPS continues to become a more widely used tool everyday , many are looking for unique ways to... more As GPS continues to become a more widely used tool everyday , many are looking for unique ways to improve the technology. However, GPS positioning in many conditions is not reliable due to the non-visibility of sufficient number of satellites. The GPS like signal transmitted by Pseudolites (PLs) can be employed to augment and provide continuity, accuracy and availability in such environment. One of the major problems associated with such navigation system is the "Near-Far" problem, which occurs due to the interference of strong PL signal and weak navigation satellite signals over certain range. Among various methods of mitigating the near-far problem, pulsing of pseudolite signal for fractions of a full duty cycle has been observed to be more effective. However, the pulsed signals affect GPS receivers depending on its characteristics such as power and duty cycle. This paper is focused on the impact of pulsed interference on GPS receiver equipment. A simple pulse blanking technique has been proposed to overcome the interference. Then, simulations for the received signal with blanking and without blanking has been carried out and graphically presented. Also, the degradation of the GPS satellite signal under the influence of a single PL and multiple number of PLs interfering with satellite tracking is analyzed. It is observed that, by increasing the pulse duty cycle of signal from 2% to 20%, the Signal to Interference (S/I) ratio decreases by 8.9 dB.

The past decade has witnessed substantial progress towards the application of low-rate speech cod... more The past decade has witnessed substantial progress towards the application of low-rate speech coders to civilian and military communications as well as computer-related voice applications. Central to this progress has been the development of new speech coders capable of producing high-quality speech at low data rates. Most of these coders incorporate mechanisms to represent the spectral properties of speech, provide for speech waveform matching, and "optimize" the coder's performance for the human ear. A number of these coders have already been adopted in national and international cellular telephony standards. The objective is to provide a overview of speech coding methodologies with emphasis that are part of the recent low-rate standards for cellular communications. Although the emphasis is on the new low-rate coders, starts with a historical perspective and continues with a brief discussion on the speech properties and performance measures. with descriptions of the codecs like waveform codecs, source codecs, Hybrid Codecs.

IOSR Journal of Electronics and Communication Engineering, 2016

Procedia Engineering, 2012

The Sense Amplifier-based Pass Transistor Logic (SAPTL) is a low energy alternative logic topolog... more The Sense Amplifier-based Pass Transistor Logic (SAPTL) is a low energy alternative logic topology to fully complementary static CMOS logic. This circuit topology allows the reduction of energy per operation via voltage scaling even in the presence of leakage energy. As the sense amplifier is an essential circuit in designing memory chips, this paper focuses the diagnosis of faults of a sense amplifier used in SAPTL circuit. For that, a particular fault model called stuck-at fault has been introduced. The advantage of the proposed approach is its ability to distinguish between the stuck at Logical '1', '0' and 'x'. Also, the design and simulation result of a sense amplifier based pass transistor circuit topology has been presented. Then, the results are compared with the stack circuit simulation results using bar graphs.