A Study Of Indoor Positioning Based On UWB Base-Station Configurations

With the growing need of position acquisition for the public, indoor positioning has become a topic for researchers in science and business. At the meantime, outdoor positioning techniques have matured over the years. GPS has high accuracy in its outdoor positioning ability, and has so far met most basic outdoor positioning requirements for the public. Hence, taking account of the mature techniques and massive values of outdoor positioning, people have turned their eyes onto the feasibility and potentials of indoor positioning. Since GPS techniques cannot simply establish indoor positions, a mature indoor positioning system has aroused general interest. A common goal for the researchers would be the high accuracy of an indoor positioning system, and further a seamless connection of it with outdoor positioning systems. Given the rise of wireless communication applications nowadays, many wireless positioning methods have been under tests for indoor positioning. Ultra-wideband as a remarkable new technology in wireless communication has been greatly developed in many countries, however, UWB research in China has not been catching up. UWB is specifically promising in complicated indoor environments, given its high resolution in time, resistance of interference and penetrating capacities.UWB transmits continuous time pulses with the range of 1 to 100 mega-pulses per second, and has a high accuracy in distancing measuring applications, as many groups have previously reported distance measuring results with an accuracy of centimeters via UWB. In this paper, we studied the effects of base-station configurations on indoor positioning accuracy via UWB. The majority of work in this paper is simulated by the CST software. We ran simulation for 6-10 GHz in the UWB with 4 types of base station configuration(eight BSs, cuboid shape: four BSs, Y shape: four BSs and l shape:3 BSs).Specific positioning application methods are based on estimations of TOA. Two methods are exploited in this paper for TOA estimation. One is based on the waveforms of signals transmitted and received, and another is through CIR peak detector. Both methods have given out ideal results. Our positioning accuracy was within 1-4 cm, and GDOP was then used for testing the rationality of the configurations engaged.