WLAN Indoor Location Technology Research And Software Realization Based On The Mobile Terminal

Service of getting position has been more and more concerned in the field of mobile communication,meanwhile,it shows great potential in the application of pedestrian navigation,emergency evacuation and military field.In the outdoor environment,GPS can achieve great precision,but it cannot satisfy the need of position service in the indoor circumstance,due to the shield of buildings.As widely application of the wireless local area network(WLAN)and the popularity of wireless mobile equipment,indoor locating based on the WLAN gradually become wireless location technology research hot spot.In the existing WLAN localization method,under the indoor multipath spreading environment,fingerprint localization which based on the signal has the advantages of high precision,low cost,low demand for hardware and just software needed become the main trend of the existing WLAN indoor location methods.This method usually is divided into two stages:offline training and on-line positioning,the former establish signal coverage map(Radio-map)for preparation,online stage using real-time collection of the RSS and established Radio-map,calculated the current position through the relevant position matching algorithm(K neighbor localization algorithm).This paper fully reviews on methods of the wireless local area network positioning,analyzes the WLAN indoor transmission attenuation characteristics and signal indoor propagation model,discusses the prospects of the location technology and the existing problems.This paper focuses on the method which based on the intensity of received signal under complicated indoor environment,and combines the tracking algorithm with the indoor locating scene,proposes an approach for the large and complex indoor environment.Considering the precision,during the offline stage,from the perspective of reducing the acquisition data of constructing radio-map and accelerating the radio-map update speed,this approach analyzes the WLAN signal indoor transmission attenuation characteristics and indoor signal propagation model,combines the Kriging interpolation method,and puts forward a kind of fast mixture model building method of radio-map.This paper takes the application in the large indoor venues as the background,the designs and implements a fingerprint indoor positioning system which based on indoor signal intensity,and a number of actual experiment have been taken in the real large indoor venues.The experiment result shows that,under complex environment,within large amount of data,this proposed approach can keep a good position precision,can reduce the work of building system,reduce the amount of localization algorithm calculation,and enhance the system operational maintainability,be helpful for indoor location technology popularization.