Design And Implement Of Non-cooperative Location System For WCDMA

Non-cooperative localization is a way to locate mobile without the active assistence of the mobile device.This technique use the technology of virtual cell to induce mobile device to reselect cell,and then sends a registration signal,by parsing out the information from the registration signal which include the mobile device's location information to locate mobile device.In the field of national defense and social security,non-cooperative position is vary valuable.With the development of society,the position based on the non-cooperation would play its role in various fields.This article focuses on the design and implemention of non-cooperative positioning system based on WCDMA.Through capture and filter the signal,screening out uspicious signal and locate them.Through a series of signal processing,we get the strength of the information signal,and through the log-periodic antenna,we get the direction of the signal.Bond strength and direction of the signal,we can realize the location of suspicious signals.At first,this paper describes the background research status of non-cooperative location.Then expound the theoretical knowledge of signal capture and signal strength measurements,including the condition that mobile device reselect the cell,and the parameters involves when mobile device reselect the cell,also include the way which will induce it.After that,we expound the signal IF,demodulate and despreading.Finally,we introduces the formula and conditions required by signal strength calculation.This theoretical part lay a solid theoretical foundation for the design and implementation of location system.Follow up,we describe the design and implementation of the system by hardware and software in detail.In the hard ware section,this paper focuses on the function of each module,signal acquisition module is responsible for signal acquisition,and then send to an IF signal processing which will get I/Q signals.After two signals be seeded into the FPGA module for demodulating,the signals will be seeded to DSP module for despreading and calculate signal strength,and ultimately be seeded into ARM module and displayed in the client software.On the basis of functional design,this paper also highlights the selection criteria of DSP and FPGA chip as well as the characteristics and the note when develop of each chip.In the software design part,which is divided int server and client.It will expound the core module in services and client,and give a detailed explanation of the important code.Finally,through a variety of scenarios,this paper also test the system by two criteria which is location success or not and the time spent in locating.