Biblio

A Visible Light Communication (VLC) is a fast growing technology became ubiquitous in the Optical wireless communication domain. It has the benefits of high security, high bandwidth, less power consumption, free from Electro Magnetic radiation hazards. VLC can help to address the looming spectrum crunch problem with secure communication in an unlimited spectrum. VLC provides extensive wireless connectivity with larger data densities than Wi-Fi along with added security features that annihilate unwanted external network invasion. The problem such as energy consumption and infrastructure complexity has been reduced by integrating the illumination and data services. The objective is to provide fast data communication with uninterrupted network connectivity and high accuracy to the user. In this paper, a proposed visible light communication system for transmitting text information using amplitude shift keying modulation (ASK) has been presented. Testing of transmitter and receiver block based on frequency, power and distance has been analyzed. The results show that the receiver is capable of receiving input data with minimum length under direct communication with the transmitter.

We propose a coding scheme for covert communication over additive white Gaussian noise channels, which extends a previous construction for discrete memoryless channels. We first show how sparse signaling with On-Off keying fails to achieve the covert capacity but that a modification allowing the use of binary phase-shift keying for "on" symbols recovers the loss. We then construct a modified pulse-position modulation scheme that, combined with multilevel coding, can achieve the covert capacity with low-complexity error-control codes. The main contribution of this work is to reconcile the tension between diffuse and sparse signaling suggested by earlier information-theoretic results.

Future wireless communications are made up of different wireless technologies. In such a scenario, cognitive and cooperative principles create a promising framework for the interaction of these systems. The opportunistic behavior of cognitive radio (CR) provides an efficient use of radio spectrum and makes wireless network setup easier. However more and more frequently, CR features are exploited by malicious attacks, e.g., denial-of-service (DoS). This paper introduces active radio frequency fingerprinting (RFF) with double application scenario. CRs could encapsulate common-control-channel (CCC) information in an existing channel using active RFF and avoiding any additional or dedicated link. On the other hand, a node inside a network could use the same technique to exchange a public key during the setup of secure communication. Results indicate how the active RFF aims to a valuable technique for cognitive radio manager (CRM) framework facilitating data exchange between CRs without any dedicated channel or additional radio resource.