Analysis of Received Signal Strength Quantization in Fingerprinting Localization

Abstract

In recent times, Received Signal Strength (RSS)-based Wi-Fi fingerprinting localization has become one of the most promising techniques for indoor localization. The primary aim of RSS is to check the quality of the signal to determine the coverage and the quality of service. Therefore, fine-resolution RSS is needed, which is generally expressed by 1-dBm granularity. However, we found that, for fingerprinting localization, fine-granular RSS is unnecessary. A coarse-granular RSS can yield the same positioning accuracy. In this paper, we propose quantization for only the effective portion of the signal strength for fingerprinting localization. We found that, if a quantized RSS fingerprint can carry the major characteristics of a radio environment, it is sufficient for localization. Five publicly open fingerprinting databases with four different quantization strategies were used to evaluate the study. The proposed method can help to simplify the hardware configuration, enhance security, and save approximately 40–60% storage space and data traffic.

Ordinal UNLOC: Target Localization With Noisy and Incomplete Distance Measures

“…From this data, we estimate that the normalized error when using Ordinal UNLOC is on the order of 0.02m/m 2 . This is comparable to, but a little worse than the normalized error expected from using carefully calibrated fingerprinting methods (normally between 0.01m/m 2 and 0.001m/m 2 ) [35]. However, we should note here that fingerprinting methods require significant precomputing and training, and are reliable only when the environment does not change.…”

“…In recent years, fingerprinting methods have become increasingly common for localization with superior accuracy [9], [29], [33]- [35] where signal distributions are mapped to specific regions in space. Though there are performance advantages to using fingerprinting, it requires extensive mapping of the environment, a priori.…”

Machine Learning Based Indoor Localization Using Wi-Fi RSSI Fingerprints: An Overview

“…A technique for eliminating useless APs and their fingerprints from radio maps was introduced in [114]. Another scheme in [115] using RSS quantization increases the consistency and efficiency of radio maps and maintains the same accuracy while using 4bit quantization instead of conventional RSS. The authors of [116] proposed a linear interpolation scheme that can be paired with extrapolation methods based on minimum observed values, mean detected values, and triangulated edge signal gradients.…”

A Survey of Smartphone-Based Indoor Positioning System Using RF-Based Wireless Technologies

“…The localization methods like fingerprinting [ 47 , 48 ] and trilateration [ 49 ] can be realized using Wi-Fi. Similarly, signal measurement principles like RSS [ 50 ], CSI [ 51 ], TOA [ 52 ], and their hybrid combination [ 53 ] can be used to provide Wi-Fi-based localization service.…”