Cognitive Radio: The future generation of communication systems

With the rapid development of communication technologies, the software radio becomes an emerging technology for flexible radio systems and have guided us into new fabulous communication tools, which resulted in improved radio communication performance, reliability, flexibility and increased value to the user to facilitate their daily life. One of the most highlighted topics of the developed communication systems nowadays is emerged as an extension of software radio technology one further step introducing the term Cognitive Radio (CR). CRs are essentially developed software radio with artificial intelligence, capable of sensing and reacting to their environment efficiently. The new introduced technology can be considered as one of the novel idea, and novel approaches in wireless communications. The presented technology was based on the situation in which wireless nodes and the related networks are sufficiently computationally intelligent about radio resources and related device-to-device communication to detect the user communication needs and to provide resources fairly to multiple and different users. This solution allows secondary (unlicensed) users to utilize the available frequency bands that are unutilized by primary (licensed) users. This feature, offered to CR users, has shown great potential for enhancing the performance of wireless networks and meeting the demands of future generation wireless applications. This paper gives an overview on the CR technology. The main objectives are to outline the fundamentals of the wireless communications technology by highlighting the new invented approaches in wireless communication systems.