Through theoretical analysis of the power spectral density of transmitted reference ultra-wideband(TR-UWB) signal,it is found that the discrete spectrum can be eliminated through the randomization of the signal′s reference and the 5.2 GHz limited band can be produced when the best time-hopping sequences are chosen,which effectively reduces TR-UWB′s interference to other wireless communication systems in the same band.The simulation proves the two theoretical conclusions and even discovers that the 5.2 GHz l...