Low ACLR communication systems for TVWS operation

Cognitive Radio has been one of the key research topics in the wireless community for about 10 years. The digital switch-over in the TV bands provides opportunities for Cognitive Radio Systems (CRS) to operate in the UHF spectrum under incumbent protection restrictions. Regulation bodies, in particular the FCC and OFCOM in the UK, have specified parameters under which CRS shall operate. Amongst the key protection measures, adjacent channel leakage ratio (ACLR) has been forced to very low levels by the FCC and the OFCOM. In this paper we present multi-carrier techniques which aim at very low ACLR. Key parameters for these air interfaces are provided based on the scenario constraints from the literature.