Abstract :
Summary form only given. With the increasing demand for high data rate wireless communications services, the requirement for efficient spectrum utilization is on the rise. Generally speaking, the spectrum usage experiences vast temporal and geographic variations ranging from 15% to 85%. Thus, cognitive radio (CR) has received considerable attentions recently, and is becoming an essential part of the emerging wireless communications standard and systems, such as the IEEE 802.22 Wireless Regional Area Networks (WRAN). In Australia, the Federal Government has committed to a $43 billion dollar program to build a National Broadband Network (NBN). NBN will deliver 100Mbps broadband services to 90% of the population, and the rest of the population will be serviced by wireless and satellite communications networks. One challenge faced by NBN is the shortage of spectrum at UHF frequencies which are particularly suited for rural coverage. CSIRO is developing new wireless communications systems to address the need of NBN for rural and regional Australians - the so-called last 10%. In particular, we are conducting research on some key cognitive radio technologies. These include reconfigurable antennas, reconfigurable active devices, out-of-band interference suppression techniques, and adaptive and reconfigurable multiple input and multiple output (MIMO) systems. In this talk, the global trend on cognitive radio will be discussed. With the NBN as the background, research activities on cognitive radio at CSIRO will be presented. In particular, new theoretical and experimental results in antennas and signal processing will be reported.
Keywords :
MIMO communication; antennas; broadband networks; cognitive radio; interference suppression; radio spectrum management; radiofrequency interference; satellite communication; Australian Federal Government; MIMO system; National Broadband Network; broadband service; cognitive radio; high data rate wireless communications service; multiple input and multiple output system; out-of-band interference suppression; reconfigurable active device; reconfigurable antenna; satellite communication network; signal processing; spectrum utilization; wireless communication standard;