Papers by VENKATAPATHY PRITHIVIRAJ
Mobile telemedicine is used in cases of emergency when an ambulance needs to communicate with an ... more Mobile telemedicine is used in cases of emergency when an ambulance needs to communicate with an expert doctor present at a distant location. With the present day telemedicine systems lacking a framework that can handle all the types of data like real time video, audio and heavy data like Magnetic Resonance Image (MRI), X-ray scans, live cardiograms, and other types of medical data, it becomes necessary to design a telemedicine system that can tackle all the problems and provide a robust telemedicine system. This paper focuses on providing an efficient mobile wireless telemedicine system using 3G+ mobile systems based on High Speed Downlink Packet Access (HSDPA) technology. The telemedicine system can handle real time audio, video streaming, interactive data and background traffic which are essential data traffic involved in a telemedicine system. The latency, jitter associated with the network is reduced without affecting the throughput by analyzing the packet scheduler available at the network layer of the UMTS-HSDPA network and various packet scheduling algorithms are tested. The mobile telemedicine system along with real time channel conditions and background traffic has been simulated in QualNet Developer Network Simulator.
Journal of Green Engineering, 2015
The IP Multimedia Subsystem (IMS) is a network architecture that consists of different network el... more The IP Multimedia Subsystem (IMS) is a network architecture that consists of different network elements linked by standard interfaces. It facilitates the delivery of multimedia services based on Internet Protocol (IP) and makes the integration of services with the internet much easier. It is a method to achieve the convergence of fixed and mobile communication devices. Optimized transmission of voice, data and video communications among the users can be achieved using IMS architecture, independent of the user's location and devices. IMS enables the user to use different services in a more efficient way in terms of energy saving. Using this technology, it is possible to make the network distribution in a better way. It reduces the energy consumption because of the capability to switch network whenever possible. This paper focuses on establishment of end to end session between two IMS terminals and analysing the performance for different applications. The performance is measured on the basis of traffic parameters and call setup delay. We have compared Inter and Intra IMS network based on a model that ensures the delivery of services without any data loss and with minimum delay.
Software Defined Radio aims at using the same hardware for different applications by the change i... more Software Defined Radio aims at using the same hardware for different applications by the change in software parameters. The reconfigurable part in a Software Defined Radio is the Digital Front-end. The modifiable parameters for different standards and technologies include bandwidth, Sampling Frequency, down converted IF, up converted IF and filter cutoff frequencies. The major goal for an ideal Software Defined Radio is to place the ADC as close to the antenna as possible. This can be achieved by Band-pass Sampling. The main objective of this paper involves the design of RF front end of a Software Defined Base Transceiver Station (BTS) which can be configured to support different technologies (here GSM/IS-95) depending on the software modifications. The RF front end is dealt for both the transmitter and receiver with appropriate MATLAB models and the simulation results.
Mobile telemedicine is used in cases of emergency when an ambulance needs to communicate with an ... more Mobile telemedicine is used in cases of emergency when an ambulance needs to communicate with an expert doctor present at a distant location. With the present day telemedicine systems lacking a framework that can handle all the types of data like real time video, audio and heavy data like Magnetic Resonance Image (MRI), X-ray scans, live cardiograms, and other types of medical data, it becomes necessary to design a telemedicine system that can tackle all the problems and provide a robust telemedicine system. This paper focuses on providing an efficient mobile wireless telemedicine system using 3G+ mobile systems based on High Speed Downlink Packet Access (HSDPA) technology. The telemedicine system can handle real time audio, video streaming, interactive data and background traffic which are essential data traffic involved in a telemedicine system. The latency, jitter associated with the network is reduced without affecting the throughput by analyzing the packet scheduler available at the network layer of the UMTS-HSDPA network and various packet scheduling algorithms are tested. The mobile telemedicine system along with real time channel conditions and background traffic has been simulated in QualNet Developer Network Simulator.
Wi-Fi, a Wireless Local Area Network technology has solely conquered the arena of short range wir... more Wi-Fi, a Wireless Local Area Network technology has solely conquered the arena of short range wireless broadband systems. To support the existing system and to further enhance the measure of performance in multipath fading environment, Wi-Fi technology is intertwined with space diversity technique which is implemented using Alamouti coding and is then introduced with interleaving/scrambling technique to take the benefit of time diversity. Diversity technique has been an essential factor in improving the quality of the wireless system's operation by providing performance almost equivalent to that of the least distorted path among various multi paths at any given time and thereby accounting for the fading effect caused in corruptive communication channels. This paper discusses the performance of space diversity techniques in Wi-Fi by comparing their Bit Error Rate (BER). Various channel models are taken into account to simulate the real time scenario of a noisy unreliable wireless environment.
... Patki Tapasya, and Khurana Swati,(2006). Summer Training Report. Department of Information Te... more ... Patki Tapasya, and Khurana Swati,(2006). Summer Training Report. Department of Information Technology, New Delhi 14. Petrovic O.,(2004). New Focus in E-Government: From Security to Trust. In Towards E-Government Management Challenges, ed. MP Gupta, TMH, New ...
Journal of Applied Sciences, 2014
2012 IEEE Green Technologies Conference, 2012
The explosive growth of mobile communications coupled with the recent findings regarding the heal... more The explosive growth of mobile communications coupled with the recent findings regarding the health and environmental hazards gives rise to a compelling case to reduce the electromagnetic pollution (EMP). While the harmful effects of EMP have been widely reported, there appears to be no objective measure to quantify EMP from the mobile communications perspective. Such an objective measure is a
The principal aim of this research article is to develop an apt transmission scheme which will co... more The principal aim of this research article is to develop an apt transmission scheme which will completely accomplish the goal of eliminating channel distortion. The effort on this work signifies and delivers a combined transmit diversity scheme that scatters the transmitter signal in multi dimension to comprehend the need to improve noise immunity. Extrapolating the diversity combining techniques, it is possible to perceive the same in the case of receivers. Space diversity is intertwined with WiMAX and the benefits have been demonstrated by incorporating various space diversity techniques and the analysis is done with respect to Bit Error Rate. Performance comparison is presented for Multiple Input Single Output and Multiple Input Multiple Output configurations. Keywords WiMAX • WMAN • MIMO • STBC • Diversity • OFDM 1 Introduction and Related Work This paper discusses a wireless MAN system that realizes the theoretical benefits of diversity techniques. Multipath propagation is the characteristic feature of any wireless communication system, which causes the multiple versions of the transmitted signal reaches the receiving antenna and these received signals have random phase and amplitude that cause fluctuations in the signal strength inducing fading and signal distortion. Diversity technique is a key factor
Wireless VITAE 2013, 2013
This report lays out the idea of introducing LPDC codes along with the spreading sequence to impr... more This report lays out the idea of introducing LPDC codes along with the spreading sequence to improve noise immunity of the signals traversing in wireless environment. With the need to make communication techniques efficient and reliable, spread spectrum has gained importance for its various added advantages. LDPC (Low Density Parity Check) have been gaining limelight in the past few years. Comprising of relatively faster encoding and decoding techniques, LDPC codes are capable of recovering the original message even after a large part of the message has been corrupted. To achieve lesser BER, spread spectrum concept has been used along with LDPC codes. In this paper, the signal was first spread and then the encoding and decoding algorithms were employed. The original message is finally recovered after de-spreading the signal. Features such as Approaching Shannon capacity, Good block error correcting performance, and Low error floor can be exploited by this technique. The presented idea would be applied to broadband wireless systems such as Wi-Fi and Wi-Max. This work demonstrates the suitability of LDPC along with spread spectrum technique in broad band wireless systems.
2013 International Conference on Communication and Signal Processing, 2013
ABSTRACT Context-aware computing is an emerging computing paradigm that can provide new or improv... more ABSTRACT Context-aware computing is an emerging computing paradigm that can provide new or improved services, which are human centered and proactive in responding to the surrounding environment by exploiting user context information. There are many applications that provide context-aware services based on the location of the user. This paper proposes the implementation of Wi-Fi based architecture for location estimation and navigation system, which is cost-effective by employing existing IEEE 802.11 network infrastructure available in many office and home environments. The proposed approach can provide meter level accuracy, which is sufficient for most location-aware applications. The positioning system is deployed to estimate the present location of the computing device such as a PDA by approximating the relation between improved Received Signal Strength Indicator (RSSI) values and relative distance between the sender and receiver. It makes use of Modified Kalman Filtering which processes the available measurements, to estimate the current value of user's position. Using the location information obtained and the inputs from the user, positioning system navigates the user to desired destination. Thus the proposed system is able to position the user in a complex indoor environment with improved accuracy.
2013 International Conference on Communication and Signal Processing, 2013
ABSTRACT Context-aware computing is an emerging computing paradigm that can provide new or improv... more ABSTRACT Context-aware computing is an emerging computing paradigm that can provide new or improved services, which are human centered and proactive in responding to the surrounding environment by exploiting user context information. In this paper an attempt is made to implement the TOA based indoor positioning scheme using Ultra Wide Band (UWB) radio. The TOA values are obtained based on symbol rate samples that are obtained from a square law device. These TOA values are then used for position estimation. Position estimation is done by two methods namely, Direct method and Objective method. It makes use of Kalman filter which processes the available measurements, to estimate the current value of user's position. The simulated results show that the Objective method gives the better performance when compared to Direct method. There are many applications that provide context-aware services based on the location of the user in emergency services which include gas explosions, aircraft crashes, earthquakes, train accidents and tsunami, where there is a major requirement to identify the presence of human beings within the disaster zones and also to provide accurate positioning and personal identification for possible presence of humans under debris.
International Conference on Wireless Communication, Vehicular Technology, Information Theory and Aerospace and Electronic Systems Technology, 2011
The most challenging problem in Cognitive radio is the detection of unused frequency bands and ex... more The most challenging problem in Cognitive radio is the detection of unused frequency bands and exploit them opportunistically for spectrum access. Cognitive radios must be able to efficiently detect the primary users even in low signal-to-noise ratio (SNR) condition and in fading environments. These difficulties can be overcome by exploiting the cyclostationary signatures exhibited by communications signal. Cyclostationary signatures are
Ultra-Wideband (UWB) communication system provides high accurate localization due to the high mul... more Ultra-Wideband (UWB) communication system provides high accurate localization due to the high multipath resolution capacity. For Ultra-Wideband (UWB) localization systems, time-based schemes namely Time of Arrival (TOA) and Time Difference of Arrival (TDOA) provide very good accuracy due to the high time resolution (large bandwidth) of UWB signals. Due to the inherent suitability and accuracy of time-based approaches for UWB systems, particularly the TDOA technique, it is proposed as the appropriate UWB localization technique for the precision automobile parking system. UWB pulse of 0.5 ns pulse width is simulated. Tests measurements are conducted using Impulse Radio UWB transceiver test setup. The TDOA values are measured for different positions of tag and reference nodes. Time-delay estimation is obtained by generalized cross correlation method and position estimation is obtained by direct method (DM) using hyperbolic navigation. The precision of the obtained position estimation i...
Orthogonal Frequency Division Multiplexing (OFDM) has recently gained a lot of attention and is a... more Orthogonal Frequency Division Multiplexing (OFDM) has recently gained a lot of attention and is a potential candidate for Fourth Generation (4G) wireless systems because it promises data rates up to 10 Mbps. A variation of OFDM is the Multi-Carrier CDMA (MC-CDMA) where the individual data symbols are spread using a spreading code in the frequency domain. Often times in cellular and military environments the desired signal can be buried below interference. In such conditions, the processing gain associated with the spreading cannot provide the needed interference suppression. This paper investigates multiantenna receivers for MC-CDMA systems. Frequency domain beamforming and time domain beamforming are studied in this paper through simulations. Time variations in the channel can disrupt the orthogonality between subcarriers. Minimum Mean Square Error (MMSE) detection coupled with MMSE beamforming is proposed for time varying channels. The simulation results show significant performan...
Journal of Green Engineering
Cooperative spectrum sensing is used as a promising solution to detect the primary user effective... more Cooperative spectrum sensing is used as a promising solution to detect the primary user effectively in a highly noisy environment, where the multiple secondary users make a global decision in relation to the primary user. The Bayesian Estimation Energy Detection (BEED) technique is one of the elegant spectrum sensing techniques available in a non-cooperative environment. So an attempt was made in this paper by incorporating the BEED in a cooperative environment, which yields the detection of primary user effectively up to a Signal to Noise Ratio (SNR) of-19 dB, when the Rayleigh fading effects are considered.
iccima, 2007
... The data to be transmitted on each carrier is then differentially encoded with previous symbo... more ... The data to be transmitted on each carrier is then differentially encoded with previous symbols, and then mapped into a phase shift keying format [5, 6]. After the required spectrum is worked out, an Inverse Fast Fourier Transform is used to find the corresponding time domain ...
… Theory and Aerospace …
AbstractSoftware Defined Radio aims at using the same hardware for different applications by the... more AbstractSoftware Defined Radio aims at using the same hardware for different applications by the change in software parameters. The reconfigurable part in a Software Defined Radio is the Digital Front-end and the parameters which can be modified for different standards ...
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Papers by VENKATAPATHY PRITHIVIRAJ