Radio map construction method

A radio map construction method performed by a radio map construction apparatus, the method comprising:

• modeling an internal structure of a building, in which a radio map is to be constructed, by a topology according to a hidden Markov model (HMM), wherein the topology represents each location in the building as a state and a geographic accessibility between locations as a transition, the modeling including collecting a fingerprint sequence through a designated application of the portable terminal;
• (a) generating a plurality of chromosomes including a set of pairs of fingerprints labeled with addresses of residences within the building and locations selected within regions of the addresses;
• (b) generating a first temporary radio map by using the pairs of the chromosomes;
• (c) performing placement of fingerprint sequences collected by using the first temporary radio map;
• (d) evaluating the placement of the fingerprint sequences by using a loss function to accumulate a penalty for a corresponding temporary radio map, whenever a labeling distance accompanied with a change from one fingerprint to another fingerprint in placements of the fingerprint sequences is determined to be equal to or greater than a maximum movable distance associated with a mobility of a user of the application of the portable terminal;
• and
• (e) repeating of steps (b) through (d) for at least one other generated temporary radio map and selecting an actual radio map for construction from among the first and at least one other generated temporary radio map based on using the loss function of each of the first and the at least one other generated temporary radio map to determine a radio map having a best placement as the actual radio map.