The Design Of Ultra Wideband Radio Pulse Shapes And The Study Of Ultra Wideband Modulation Scheme

Ultra-wideband (UWB) pulse communication has such characteristics as high system capacity, low power of emission, exceptional multi-path immunity, simple structure and deployment good security and so on. In the Ultra-wideband communication systems, based on the restriction of Federal Communications Commission (FCC) emission mask, the methods of designing impulse pulse waveforms and the modulation scheme which has good performance are the key technique of the Ultra-wideband communications.This paper's main contents in the methods of designing impulse pulse waveforms and the pulse modulation scheme are as follows:1) Several methods of designing ultra-wideband waveform are summarized. And the relation between the normalized energy of the n-th derivative of the modified Hermite Polynomial and the pulse shape parameterαas well as the differential coefficient the n-th order were studied. By choosing different pulse parameter, we get a set of waveforms based on the modified Hermite Polynomial pulse. Then two novel methods to design ultra-wideband pulse are proposed in this paper. Firstly, the optimal Ultra Wideband waveform is get by the linear combination of the N modified Hermite functions. Secondly, According to the Least Square Estimator (LSE) criterion the pulse waveform is designed, whose PSD approaches the spectral mask standard. The simulations indicate that the pulse obtained from both the two methods can approach the spectral mask standard accurately and improve the utilization of the spectrum. And it can overcome some shortcomings of to be used in the past.2) A pulse shape modulation scheme based on orthogonal UWB pulse is proposed, which is on the basis of the orthogonality and no DC off-set of modified Hermite polynomial function. The results show that the method can improve system's performance and decrease the bit error rate.It is of certain significance in both theory and engineering for this work to exploit some new approaches for the design of Ultra Wideband pulse shapes and the study of Ultra Wideband modulation scheme.