Software Defined Cognitive Radio Prototype toward IMT-Advanced Wireless Communication Systems

This paper summarizes the current status of frequency allocation plan in Japan and discusses how to create new frequency bands for the next generation mobile communication systems. Then the needs for cognitive radio are summarized such as one of the solutions, and the current situation of the research and development is also shown. Finally, some of the research results on cognitive radio in the author's institute are shown

I Introduction

A number of wireless access systems have already been available to users. For example, in cellular systems, use generation and generation mobile communication systems can be used. Apart from cellular communication systems, wireless access systems include high-speed mobile access systems, via wireless LAN using 2.4, 5 and 25GHz bands that are lower-priced and pursue higher-speed at the order of several tens Mbps, and fixed wireless access (FWA) systems using 22, 26, and 38GHz bands that enable transmission rate at over 100 Mbps, though higher in price. Moreover the users enjoy broadcasting services such as high definition digital terrestrial television (HDTV) and radio. Sooner or later, the new systems are standardized and frequency allocation planning is one of the important issues. The author thinks that the technology that can create available frequency bands on the current frequency allocation plan is cognitive radio (CR) [1] [4].