Based On Power Line Position Fingerprint Set Positioning Structure Technology

There are kinds of household equipments, wireless sensor and perceptivenetwork in intelligent environment. The uncertainty of personnel activities makes itdifficult for researchers to develop timely and accurate positioning system.Wireless signals will fade when it travels in space, which means you will receivedifferent strength of the signal at different places. Therefore, researchers can use thedifferent signal strength for space orientation in the interior space. This design usesthe power line as the antenna in intelligent environment. By inputting broadbandsignal into the power line, the researchers can construct the fingerprint of position anddevelop positioning system which goes with the characteristics of the intelligentenvironment with the matching pattern technology.Firstly, the design adopts coupling technology to the power line for twoobjectives：Shielding low-frequency signal and inputting high-frequency signal intothe power line. The design of the system requests high stability, accuracy of the signaland purity of the frequency. To fulfill these requirements, the design uses NC functionsignal generator which makes DDS signal producing as core technology. Theresearchers chose AD9850chip of American AD Company, and connects two piecesof AD603in order by controlling single chip microcomputer Arduino, then capacitivewill coupling between the two polesSecondly, the design uses switched-capacitor filter techniques to reduce muchrandom interference of the low-power line. Switched-capacitor takes advantages ofthe storage and transfer of the charge to process the signal. With the help of amplifier,operational amplifier and comparator and so on, we can produce, transfer and processhigh-frequency signal.Thirdly, we use the method of broadband high-frequency digital and controldigital receiver chips MC3661HN by single chip microcomputer Arduno to receivehigh-frequency signal. The frequency of the high-frequency signal received isdisplayed on the LCD.Last, we chose plenty of spots in the specified intelligent environment to collectfingerprint and construct data base of the positioning fingerprints outline. We willmeasure the strength of the signal received at every different spots and make sure thetwo-dimensional geographic coordinate of that spot.