| As the rapid increase in the data services and the multimedia services, the needsof people in the area of the positioning and navigation are growing, particularly inthe complex indoor environments, such as the airport hall, the exhibition halls, thewarehouses, the supermarkets, the libraries, the underground car park, the mine envi-ronment, and so on. It's important to identify the location information of the mobileterminals or their holder, facilities and items in the indoor. However, by the restrictedof the positioning time, the positioning accuracy and the complex indoor environment,the relatively perfect positioning technology, such as GPS, is still unable to use fullyin the indoor. Therefore, the experts and scholars have proposed many indoor posi-tioning solutions on the wireless network technology,included ultrasonic positioningtechnology, bluetooth technology, infrared technology, radio frequency identificationtechnology, ultra-wideband technology, wireless LAN, and so on. In the future, Thetrend of the wireless positioning technology is combining the outdoor positioning withthe indoor positioning to achieve the seamless, accurate localization. The existing net-work technology can not fully meet this requirement. Compared with the traditionalnarrowband systems, ultra-wideband wireless positioning technology has many ad-vantages, such as great penetrating power, low power consumption, anti-multipatheffective, safe and low-complexity systems. In particular, it can provide very pre-cise positioning accuracy. Ultra-wideband wireless positioning will become the bestresearch and application choices in the future wireless location technology.UWB is a new wireless communication technology, which is enormous differ-ence with the tradition communication technology. To the UWB communication sys- tems, the data are transimted and received via narrow pulsed in or below the nanosec-ond level to get the GHz level bandwidth without the carrier used by the traditionalcommunication systems. UWB technology can be used to locate the position ex-actly in the indoor, for example, finding the soldier's position in battlefield, trackingthe robot's movement and so on. First, the UWB technology is introduced simply;then, the tradition positioning methods are summarized and analyzed; Finally, the pa-rameters estimation about positioning via UWB sources are researched and discussedthoroughly. The research work is done in the TOA estimation, the AOA estimationand the TOA/DOA jointly estimation, as well as target tracking. The main innovationwork as follows:(1) The problem of propagation delay estimation in DS-UWB system over mul-tipath fading channel is studied. An estimation algorithm based on subspace decom-position with high resolution and low complexity is proposed. This method obtainsdelay estimation through decomposition of time average correlation matrix of slidingcorrelation output in signal and noise subspaces, MUSIC spectrum computation andmaximum value searching. Comparison of time resolution and complexity betweensliding correlation method and conventional correlation MUSIC method is conducted.Computer simulation results show that the proposed method can estimate time delayin near one chip duration and its performance is better than of conventional methods.(2) The TOA estimation is investigated for ranging applications with UWB sig-nal source. TOA estimation in the frequency domain is proposed, which reduces thesampling rate and the power consumption of receiver, as well simplified the receiverStructure. The computational complexity and performance of both algorithm based onthe state space are compared. The simulation analysis through the practical channelmodel show that any of TOA frequency domain algorithm can achieve precise loca-tion estimation, but the computational complexity of normal power method is lower.The proposed methods particularly suited to the positioning applications.(3) The method of DOA estimation based on UCA antenna structure is presented.First, using the mode-space transform,the signal model based on UCA antenna ismapped as ULA signal model. Then, a focusing matrix in frequency domain is con-structed after segmented FFT transform and the received source data of all frequenciesare focused on a fixed frequency. Finally, the DOA of different sources is estimatedthrough the MUSIC algorithm. The simulation results show that the presented method can achieve better probability of angular resolution. And the range of angular estima-tion expends from 0?～360?.(4) A kind of TOA/DOA jointly estimation method is proposed using UWBsources, in which the UWB time domain signals from the antenna arrays are trans-formed to the frequency domain. The TOA and DOA information of the target nodein a two-dimensional space is estimated by the traditional MUSIC algorithm. In thismethod, the high time distinguish characters of UWB signals and DOA informationfrom target nodes are combined to increase the positioning estimation accuracy, andthen, through the extended kalman filter, the target location signals obtained fromTOA/DOA jointly estimation are smoothed, and the moving track of target nodes ismore closed to the actual one.(5) A positioning and tracking system is designed for lunar rover as a movingtarget using UWB ransmitted source. In the assistance of the lander, the TDOA esti-mation incident to both receiver antennas from the UWB source is transformed intothe AOA estimation. Combining the receivers'location information and choosingone of them as coordinates origin, the location of the moving target is figured out.Based on the system model, the moving target positioning and tracking algorithms arediscussed using the kalman filter. Finally, by the computer simulations, the systemerror of positioning algorithm is analyzed, as well the improvement on the trackingalgorithm when the target is moving at uniform velocity and accelerate velocity. Thefeasibility and validity of the proposed method are assessed. The accurate positioninginformation is provided in order to the lunar rover's automatic control and navigation.
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