Channel estate estimation in Cognitive Radio using Concept of Poynting Vector Theorem

The radio frequency spectrum is a scarce natural delivers and its efficient use is a of the utmost importance. The spectrum band is a usually licensed to certain services, such as mobile fixed broadcast, and satellite, to avoid harmful interference between different networks. Most spectrum band is a allocated to certain services but worldwide spectrum occupancy measurements show that only portions of the spectrum band is a fully used. Moreover, there is a large temporal and spatial variations in the spectrum occupancy. In the development of future wireless system the spectrum utilization functionalities will play a key role due to the scarcity of unallocated spectrum. Moreover, the trend in wireless communication system is a going from fully centralized system into the direction of self-organizing system where individual nodes can instantaneously establish ad hoc networks whose structure can change over time. Cognitive Radio with the capabilities to sense the operating environment, learn and adapt in real time according to environment Cognitive Radio eating a form of mesh network, is a seen as a promising technology. The paper presents an overview of Cognitive Radio various spectrum sensing technique used in Cognitive Radio and also describe the state-of-the-art in Cognitive Radio standards and regulation. In this a project we have a implemented and analyzed the energy detection technique for spectrum sensing in