室内Radio-map建立方法与性能分析

哈尔滨工业大学工学硕士学位论文AbstractNowadays in the indoor wireless communication field the wireless local areanetwork (WLAN)became a hotspot.The broad deployment and high speed ofWLAN guarantees the WLAN based localization a broad prospect.In the widelyused WLAN fingerprinting localization system,reliable,efficient RSS informationis needed to make the system work.There are mainly two phases in the fingerprintalgorithm:the off-line phase and the on-line phase.In the off-line phase,Radio-mapis established and in the on-line phase,the localization system obtains the currentRSS value and using the Radio-map to compute the estimated position.While most researchers in the world focus on the localization algorithm part ofthe system,this paper hold the view that as the basic of the system,the constructionof Radio-map should not be ignored.To prove this point this paper presents a time-saving and accuracy-keeping Radio-map construction algorithm.First,the basic principles of the location fingerprint-based algorithm areintroduced and the KNN algorithm is used to check the performance of differentRadio-map.Then the stabilization of measured reference point's data is analyzed.In order to reduce the localization error by constructing a reliable Radio-map,an odd data filtering algorithm is proposed to remove the abnormal sample fromRSS data.In this algorithm,all the RSS samples in the same reference point areconsidered as a whole and the distribution model of them is built to establishfiltered Radio-map.The performance of original Radio-map and filtered Radio-mapis verified by KNN.At the mean time,to fix the principal value of measured RSSsamples,a grouping algorithm is proposed.Finally,to make the Radio-map establishing less time consuming,a gridinterpolate Radio-map construction algorithm is proposed.Due to the loss ofposition information between the interpolated data and the measured data,thelocalization error increases.So to maintain the localization accuracy while using theinterpolated Radio-map,an odd data filtering based grid interpolate Radio-mapconstruction algorithm is proposed.Experimental results prove that this algorithmcould completely satisfy application requirements and provide theoretical andtechnical supports to the establishment of WLAN indoor location systems.Keywords:WLAN,Radio-map,Location,grid interpolating