Implementation challenges for UHF white space cognitive systems

The author presents a collection of slides and concludes: (1) Recent developments in cognitive radio are 802.22 and UCoMS, both targeting UHF DTV band white space; (2) A variety of sensing techniques are available, e.g. sense ATSC -5 to -25dB; (3) DTV sensing requirement for indoor portable devices is very tough because of losses due to antenna height, building penetration and small antenna; (4) Assist sensing with geo-location technique; (5) Easy to block DTV using adjacent channels; (6) Better to use UHF white space with fixed (e.g. 802.22) or planned (e.g. 7th multiplex) manner; (7) UHF white space is much lower in UK than US. Using only channels with free adjacent channels there´s about 30MHz in US and incomplete coverage in UK; (8) New applications of cognitive radio should focus on reusing and reselling other licensed bands.