Study, Based On The Performance Of The Rake Receiver In Uwb Wireless Communication System

In 1960s, the conception of Ultra-Wideband (UWB) was proposed by some scholars as a "carrierless system " using impulse signal. In the consequent several decades, because of the dominant station of the research and application of the carrier communication, the development of UWB nearly stopped. Until 1993, the American scholar R.A.Scholtz published a famous paper in Milcom'93 proposed the multiple access technology using the impulse radio to implement the Time-Hopping modulation. Then the development of UWB continued. Recently, more and more experts and scholars devoted to this area and have acquired lots of theoretic results and implement schemes. Now, the UWB technology is one of the key technologies to implement the indoor short distance wireless communication.In this paper, the key technologies in UWB such as signal format, modulation scheme, channel model and Rake receiver are analyzed firstly. Base on this work upon, two kinds of UWB wireless communication system are proposed. One system uses the Rake receiver base on BPSK modulation and Maximum likelihood channel estimation. The other system uses the Rake receiver base on orthogonal modulation and blind channel estimation. Analyses are taken in the two systems within the aspects of impulse shape, modulation scheme, Rake receiver structure, channel estimation algorithm and diversity combination scheme. Computer simulation was carried up to obtain the performance of this two system using Matlab tool. The IEEE 802.15.3a model was used in the simulation. The data of BER performance with different number of path captured, different diversity combination scheme and different modulation scheme were obtained through the simulation. The data of MSE performance using for evaluating the performance of channel estimation algorithm were obtained too. After the analysis of the simulation results, we can conclude that the two systems both have good BER performance within low complexity and the channel estimation algorithms have good MSE performance too.