# Indoor Localization Algorithm Based on Information Gain Ratio and Affinity Propagation Clustering

## TL;DR

This paper introduces a new indoor positioning method that reduces redundant access points and improves accuracy using clustering and Bayesian techniques.

## Contribution

The novel approach combines AP location discrimination with affinity propagation clustering and Bayesian methods to enhance indoor positioning accuracy.

## Key findings

- The proposed method reduces the number of APs in the fingerprint database by up to 72.78% with minimal accuracy loss.
- Using affinity propagation and Bayesian methods, positioning error is reduced by 11% to 39% compared to other algorithms.
- Experiments on real-world and public datasets confirm the effectiveness of the AP filtering and positioning strategy.

## Abstract

In indoor positioning systems, it is common to use existing AP deployments within buildings to build a fingerprint database, providing positioning information during the online phase. However, AP layouts inside buildings often contain a large number of redundant APs, which leads to the improvement in positioning accuracy leveling off as the number of redundant APs increases, while also increasing the computational load of indoor positioning services. To address this problem, the thesis proposes a method for calculating the AP location discrimination capability and combines the location discrimination capability with coverage to eliminate redundant APs. Experiments conducted in real indoor scenarios, as well as on the Crowdsourced dataset and the SODIndoorLoc dataset, validate the results. The results show that the redundant AP removing strategy ensures that the average positioning accuracy fluctuates by no more than 5% compared to the unfiltered case, while significantly reducing the number of APs in the fingerprint database—by 64.43%, 72.78%, and 59.62%, respectively. In the position estimation phase, this paper uses affinity propagation clustering for coarse positioning and combines Bayesian methods for fine positioning. Compared with GMM, K-Means, and the pointwise algorithm, the average positioning error of the proposed method is reduced by 11% to 39%.