Research On Time Difference Localization Algorithm And Timeing Information Transmission Implementation

With the rapid development of global electronic information technology, GPStechnology is becoming much more mature, which provides a good platform for passivetime difference estimation. Since passive time difference location technology aresuperior to active positioning technology in many performances, the passive timedifference location technology acheives high attention, many scholars at home andabroad focus on the research.This Dissertation revolves around how to realize the passive time differencepositioning system for further study. Firstly, the theory of passive time differenceestimation and passive time difference localization algorithm are intruduced, andMatlab simulation are made within different simulation environment. Secondely,analysis of those algorithms are made through the simulation results’ mean and meansquare error. Finally, the connected TDE algorithm and connected time localizationalgorithm are introduced. Matlab simulation results show that, with the connected timedelay estimation algorithm, the convergence speed are speeded up and the number ofEDTE filter order are greatly decreased, which is useful to the project implementation.When the connected time localization algorithm is used, even when TDOA error is large,it can estimate the target location accurately and prevent the disconvergence of thealgorithm.Then how to realize the passive time difference positioning system is introducesd.First of all, implementation framework of passive time difference positioning system isinturduced in details. Signal is received by digital plate, and after has been added timeaccording to GPS is changed into accurate timing data, which is transmited to DSP.Then accurate timing data is sent to PC after been received, checked, parsed by DSP.Finally PC uses received accurate timing data to calculate time delay and locationposition. It can seen from the above describtion that communication mechanism is thekey of passive time difference positioning system, so then data communicationmechanism is described in details. As the bridge of FPGA and PC communication，DSP plays a very important role; therefore, how to realize conmunication through concurrent execution of multithreaded application mechanism in precise timing modeby DSP is introduced, which maintains the whole system in an orderly way of work.Finally experiments of passive time difference location system have been done.The comparative analysis of the results has been made through debug software.Experimental results show that system data communication mechanism and DSPmultithreaded programs mechanism can be normal operation. When System useshomologous clock, the time delay is0ns, for IF modulation signal which is produced bysignal generator, we can get precise time delay results, which error is less than100ns.