Waveform Design Based On CUWB

With the rapid development of information society, the demand for mobile communications and wireless broadband access services soon grow. How to share spectrum resources and have efficient using of wireless spectrum has become an urgent problem to the area of wireless communication. Cognitive ultra-wideband as a new wireless communication technology has a unique advantage at the aspect of spectral efficiency compared with conventional radio, and become a focus of international research.In the first part of the paper, there are discussion of the feasibility of combining ultra wide band and cognitive radio system, and systematic and complete analysis of relative technical domains. The merits and demerits of Gaussian pulse, Raised cosine pulse, Hermite polynomial pulse and Prolate Spheroidal Wave Functions were analyzed in this paper. To deal with the problem of low spectral efficiency, a novel UWB pulse shaping algorithm which use liner combination of Approximate Prolate Spheroidal Wave Functions (APSWFs) to shape the UWB pulse was proposed in this paper. Simulation show that the pulse waveforms shaped by this method have higher spectrum efficiency.In order to transplant the improved pulse shaping algorithm into CUWB system, the key technologies of CUWB system such as spectrum sensing, spectrum sharing adaptive waveform design were analyzed in this paper. According to the hierarchical framework of CUWB system and dynamic spectrum mask, a novel CUWB adaptive pulse shaping algorithm which based on Least Square Error (LSE) principle was further proposed. Simulation results show that the new method can conform the dynamic spectral mask in real wireless communication environment and provide a flexible and easy solution to CUWB system get into real.