Improved Collaborative Spectrum Sensing Scheme for Maritime Cognitive Radio

603-612Expeditious growth in wireless networks for numerous wireless services and applications lead to the increase in demand for radio spectrum in both terrestrial and marine wireless communications. Radio spectrum is scarce as the available spectrum is already been allocated to various applications. Cognitive radio technology is an optimistic solution for the spectral scarcity. In Cognitive Radio Networks (CRN), the unused licensed bands are dynamically accessed by the unlicensed secondary users for data transmission. Spectrum Sensing (SS) is the key technique to detect the presence or absence of the primary users. SS for terrestrial wireless communication have been studied vastly. This paper is aimed to study SS for Maritime Cognitive Radio Networks (MCRN) which is daunting as SS in MCRN depends on the sea state. Existing work on SS in MCRN deals with Classical Energy Detection (CED) which is a straight forward procedure with low complexity and can be applied generally to any signal irrespective of its format. Here we intend to perform SS in MCRN using Improved Energy Detection (IED) which surpasses the performance of CED without ruining its general attributes. Evaluations and analysis are carried out using detection probability performance metric for both CED and IED, simulated and compared for different sea states

Design and Implementation of PV based Energy Harvester for WSN Node with MAIC algorithm

Wireless sensor networks (WSNs) are hardly in need of an additional source of power other than the normally used batteries, to increase the lifetime considerably. In this paper, mathematical modeling of photovoltaic energy harvesting (PVEH) system for the WSN is presented. The system comprises of the solar PV panel, boost converter as maximum power point tracker with moving averaged incremental conductance (MAIC) maximum power point (MPP) algorithm, Ni-MH battery for energy storage, compensator, buck regulator and the mathematically modeled WSN mote. MAIC algorithm is proposed to avoid the effect of drastic variations in input irradiance, in locking the MPP point. WSN mote is modeled in both active and sleep state based on the power consumption. To maintain the voltage stability, proper compensator has been designed for the proposed system. The performance of the system is tested for dynamic variations of environmental conditions using MATLAB simulation. The proposed system has 50 to 60 percent improved conversion efficiency when compared to the conventional direct coupling method. The parameters of the photovoltaic panel model have been validated through experimentation. Also the practical verification of the operation of MPPT circuit has been performed