Multi-band OFDM: A cognitive radio for UWB

Ultra-wideband (UWB) communication systems are able to achieve high data rates by utilizing a large amount of spectrum. This signal typically overlaps with many existing and potentially future services. Therefore, for an UWB device to be successful, it will need to be able to identify and protect these victim receivers via cognitive radio techniques. Multi-band orthogonal frequency division modulation (MB-OFDM) has an inherent ability to perform the functions of a cognitive radio. With minimal changes to the technology, it is possible to identify victim services and provide the necessary protection mechanisms via spectral notches based on distance, bandwidth and other such measures. In this paper, the techniques for detecting interfering signals, estimating the distance between victim and interfering devices, and shaping the spectrum to mitigate interference into the victim receiver are described.