Subir Kumar Sarkar

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In this paper we describe the channel impairments and equalization methods currently used in WiFi, WiMax and WCDMA. After a review of channel model for Intelligent Transportation System (ITS), we proposed an equalization method which will be useful for the estimation of strong multipath channel at a high velocity.
A characteristic feature of ad hoc networks is the infrastructure less and seamless connectivity of the wireless mobile nodes. Mobility plays an important role in the connectivity of these nodes. In this paper a performance comparison of five important mobility models; Community Model, Group Force Mobility Model (GFMM), Reference Point Group Mobility(More)
These days, with technological advancement, it is very easy for miscreants to produce illegal multimedia data copies. Various techniques of copyright protection of free data are being developed daily. Digital watermarking is one such technique, where digital embedding of the copyright information/watermark into the data to be protected. The two major ways(More)
Quantization index modulation (QIM) watermarking proposed by Chen and Wornell provides computational efficient blind watermarking based on Costa's dirty paper codes. The limitation of this is its vulnerability against amplitude scaling distortion. The present work is proposed to solve this problem based on angle QIM within spread transform dither modulation(More)
A Mobile Ad-hoc Network (MANET) is a dynamic wireless network that can be formed without the need for any pre-existing infrastructure in which each node can act as a router. One of the main challenges of MANET is the design of robust routing algorithms that adapt to the frequent and randomly changing network topology. A variety of routing protocols have(More)
A mobile ad hoc network (MANET) is a network consisting of a set of wireless mobile nodes that communicate with each other without centralized control or established infrastructure. The mobility model represents the moving behavior of each mobile node (MN) in the MANET that should be realistic. It is a crucial part in the performance evaluation of MANET. In(More)
This article presents a framework to hybridize the rough set theory with a famous swarm intelligence algorithm known as Particle Swarm Optimization (PSO). The hybrid rough-PSO technique has been used for grouping the pixels of an image in its intensity space. Medical and remote sensing satellite images become corrupted with noise very often. Fast and(More)
In this paper the focus is on the performance study of four routing protocols, namely AODV, AODVUU, RAODV and AOMDV. We call these protocols AODV family of protocols as all these protocols consider AODV as the base routing protocol upon which these protocols are improved. Even though AODV and AODVUU are not different protocols, we wanted to see if there is(More)
The increasing demands and requirements for wireless communication systems especially in settings where access to wired infrastructure is not possible like natural disasters, conferences and military settings have led to the need for a better understanding of fundamental issues in TCP optimization in MANETS.TCP primarily designed for wired networks, faces(More)