The Research On Weak Signal Detection And The Design Of Wireless Location System In Disaster Environment

The disasters such as earthquake, landslide and mudslides happen frequently every year in the rld, especially in China. Lots of people are buried in ruins when such disasters occur. In order to icue the buried victims, some traditional methods such as rescue dogs and life detector are quently utilized. However, these methods suffer from several significant disadvantages, for tance, low efficiency and short working time. To alleviate this problem, a novel phone-based reless location system for disaster relief is proposed as more and more people carry a mobile one nowadays. Besides, the signal of phones is much stronger than vital signal.In order to locate the mobile phone, we should detect the radio signal first, and this is related to concept "spectrum sensing", which means detecting the signal on a fixed frequency. This sertation analyzes the performance of spectrum sensing in AWGN channel and Rayleigh channel, compares the detecting performance of several fusion rules in Rayleigh channel afterwards. A vel approach is proposed to find the best fusion rule based on extensive simulations. Furthermore, impact of the detecting performance of the fusion rules is analyzed when the reporting channel not ideal. It is found that the probability of false alarming of all fusion rules has a lower bound, I the expression of the probability of false alarming is deduced. The expression deduced in this rk provides a guideline to improve the detecting performance of the fusion rules.Based on the investigation, a novel wireless location system for disaster relief is proposed, and scheme of the rescue system is designed. In the proposed system, the pseudo base station luces the cell phone in disaster area to transmit wireless signal, based on the channel model, a ation algorithm is adopted to compute the coordinate of the mobile phone. To validate the alization system, a demo is designed. This dissertation focuses on the design of the localization dule, including extracting the information of latitude and longitude of the GPS signal, and lverting them to information in Cartesian coordinates. Furthermore, some key modules of the :udo base station is designed in this work.