Research On Interference Between UWB Wireless Communications And Existing Wireless Systems

Ultrawideband radio is a novel wireless communication technology,to which more and more attentions have been paid.UWB wireless communications techniques have many merits,including an extremely simple radio architecture,low-cost design,large processing gain,low power,fine time resolution,which make UWB radio an key role for medium and short range high rate wireless communications in future.And it will have a broad application prospect in wireless communication field.As the UWB technology is a kind of radio technology sharing frequency band with other kinds of radio technologies,it is crucial to deal with the interference problem between the UWB communication systems and narrowband communication systems for the further development of UWB system.Firstly,this article surveys the history and the research status of UWB.And the characteristics of the UWB radio signal are analyzed,comparing to some traditional radio.A variety of concentrated problems and fundamental questions are listed.And the main research contents of this thesis are pointed out.It also introduces the definition of the advantages of UWB and explores the UWB communications systems and other wireless communications systems interfere with each other research methods.Then,this paper analyzes the impact of interference produced by IEEE 802.11a system on the UWB system. A bench is made by ADS.And the UWB Interference bench provides simulation of a UWB transmitter and receiver with interference from an 802.11 a source.Simulations can sweep the interference power level relative to that of the transmit signal.A correlator despreads and bit slices the received UWB signal.Simulating results shows the impact of interference.System signal noise ratio and bit error rate are reflected in the indicators in simulation models.The analysis of the system to achieve more comprehensive and more valuable,also provides a favorable analysis of the problem.Interference of two standards CDMA system will enable the the largest transmission power of UWB devices.The minimum safe distance research of UWB devices with the TD-SCDMA systems shows that, if we take useful measures,UWB devices will not be harmful to TD-SCDMA systems. Finally,the Gaussian pulse and its derivative function as information carriers of UWB communications are discussed.The mathematical model of Gaussian pulse was investigated.Based on the restriction of federal communications commission emission mask,the linear combination of twelve Gaussian Monocycle derivatives were investigated, a iterative combination pulse method was presented.Several numerical experiments were given to demonstrate the efficiency of this method.And then to create ADS model once again proves that the combination of pulse has a good performance.All these study will provide some useful ideas and methods to achieve the coexistence between UWB and other wireless systems in the band.