The spectrum sensing algorithm using the soft decision algorithm in cognitive UWB system

In this paper, sensing algorithms to select the available sub-bands in the cognitive UWB system are proposed; grouped time division sensing technique and decision methods for sub-channel selection. We employ energy detection method for spectrum sensing, which has low complexity in the wide spectrum sensing. Grouped time division sensing technique is proposed to transmit training symbols and to measure the interference level of sub-bands efficiently. It simplifies the procedure of spectrum sensing, because this scheme requires less number of sensing blocks in receiver. Finally, the decision methods, hard and soft decision, are proposed and compared. Proposed sensing algorithms in this paper can provide wider application of cognitive UWB system and smarter service in coexisting with other wireless system.