| UWB is the wireless communication technology of new generation, though its historical origin can be traced back to 100 years ago. The ultra wideband(UWB)wireless technology in the modern meaning, appears in 1960s. As one different form from traditional communication technology, UWB is one that does not have carrier communication technology, namely it does not adopt the signal carrier, but utilize and receive the non- sinusoidal wave narrow pulse of grade from second to pico-second to transmit the data. The goal of UWB wireless transmitting communication system is to offer high-speed communication for indoor environment and communicate for the short distance mainly. But the wireless communication technology, now apply to the indoor environment at the same time, this has determined that the existing principles to wireless technology are not applicable in UWB system. Indoor environment is complicated and changeable quickly, this requires us to find more suitable channel estimation algorithms which should perfect the performance of the receiver.Fractal theory is a new developing theory in nonlinear science, and get quickly development in last ten or twenty years, apply to the nearly whole fields of natural science and social science extensively. It is focus studied both at home and abroad and front subject. Selfsimilarity is the main description of fractal theory. That means that the dynamics factor happens to coincide with wireless transmission environment, some research indicates that the wireless channel has fractal characteristics, the electromagnetic wave spreads with fratcal factors, some study point out that the fractal characteristic that the scattering body surface has will be carried to the scattering signal. The results of these research have pointed... |
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