Vivekanand Mishra

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FSO (free space optical communication) is less costly and use frequency spectrum which is license free. In this paper, to send the electrical signal in the form of optical signal and reconstruct it in electrical signal we will use coherent detection technique. We also used OFDM techniques, which mitigate the consequence of frequency selected fading and the(More)
Watermarking is the process of hiding a predefined pattern or logo into multimedia like image, audio or video in a way that quality and imperceptibility of media is preserved. Predefined pattern or logo represents identity of an author or rights. In recent years, rapid growth in digital multimedia has been noticed. Digital data (image, audio, and video) is(More)
This paper presents the design of a metamaterial inspired symmetrical slotted patch antenna for triband operation with center frequency 2.5 GHz. antenna is designed. The outer dimensions of the patch are designed such that the antenna resonates at the upper resonant frequency. In addition, the dimensions of the slots are designed to control the lower(More)
Digital video watermarking has drawn the attention towards authentication and proof of ownership. Uncompressed domain watermarking has flourished over the years and related algorithms have been implemented on the software platform. Software watermarking algorithms work offline where videos are captured through device and embedding algorithms run on a PC(More)
In mobility management, detection of spectrum hole plays very important role for doing spectrum handoff mechanism. Operation of the cognitive radio depends on the spectrum sensing which is the most important task in case of cognitive radio network. Detection of spectrum holes (underutilized sub-bands of the radio spectrum) estimates average power,(More)
Watermarking is the process of hiding a predefined pattern or logo into multimedia like image, audio or video in a way that quality and imperceptibility of media is preserved. Predefined pattern or logo represents the identification of the author. In recent years, rapid growth in digital multimedia has been noticed. Digital videos are widely exchanged on(More)
The digital watermarking is a multimedia technology for information hiding which provides the authentication and copyright protection. The digital images are easily exchanged through internet and threaten to some malicious attacks. Wavelet based frequency domain watermarking provides the robustness against different attacks. Bit plane slicing scheme of(More)
Recently, Porous Silicon (PS) is emerged as novel and unique material as a stable nano scale optical sensor device. In this work, one dimensional (1D) Photonic Bandgap (PBG) structures such as single layer (SL), Distributed Bragg Reflector (DBR) and Microcavity (MC) using PS material are suggested as optical sensor applications. Design and simulations are(More)
This article includes dispersion characteristics of optical waveguide with helical windings, and compression of dispersion characteristics of optical waveguide with helical winding at core-cladding interface for five different pitch angles. In this article dispersion characteristic of conventional optical waveguide with helical winding at core - cladding(More)