A means for establishment of nearest neighbors points database of all reference points is proposed

expand the single relationship of test points and reference points to net relationship of test points and reference points and test points’ close neighbor points and other reference points.So that it make full use of the RSSI fingerprint database useful information

effectively avoid the interference of the indoor complex environment.Establish a RSSI fingerprint database of reference points

and seek the K-nearest neighbor points for each reference point to establish a close neighbor points database;seek the test points’K-nearest neighbor points

then find the exist points both in the K nearest neighbor points entries from the neighbor points database

then weighted sum all of K nearest neighbors points and n reference points

obtain the estimate coordinates of test points.