Title :
Transmit Power Allocation among PSWF-based Pulse Wavelets in Cognitive UWB Radio
Author :
Zhou, Xiaofei ; Zhang, Honggang ; Chlamtac, Imrich
Author_Institution :
CREATE-NET, Trento
Abstract :
Ultra wideband (UWB) technology has been considered as one of the suitable transmission techniques for implementing a cognitive radio system, where spectrum-agile UWB waveforms achieve adaptation features. One approach for designing such waveforms relies on orthogonally combining PSWF-based pulse wavelets. In a cognitive UWB radio environment with N users, with respect to the case of one sub-band accessed by one user, whose transmitting signal is M-ary pulse shape modulated, we get different eigenvalues by transmitting these pulses in a multipath fading channel, we propose water filling scheme, depending on the different eigenvalues, to optimize the power allocation among them. Simulation results show that the scheme improves the sub-band channel data throughput compared with the scheme that power is equal allocated among these pulse wavelets, when the SNR is low, which is the normal case in UWB communications
Keywords :
cognitive radio; eigenvalues and eigenfunctions; fading channels; multipath channels; ultra wideband communication; PSWF-based pulse wavelets; SNR; cognitive UWB radio; eigenvalues; multipath fading channel; power allocation; prolate spheroidal wave functions; signal transmission; subband channel data; ultrawideband technology; water filling scheme; Cognitive radio; Eigenvalues and eigenfunctions; Fading; Filling; Pulse modulation; Pulse shaping methods; Shape; Throughput; Ultra wideband communication; Ultra wideband technology;
Conference_Titel :
Cognitive Radio Oriented Wireless Networks and Communications, 2006. 1st International Conference on
Conference_Location :
Mykonos Island
Print_ISBN :
1-4244-0381-2
Electronic_ISBN :
1-4244-0381-2
DOI :
10.1109/CROWNCOM.2006.363458