Paper Info
Title
A Novel Algorithm for Multipath Fingerprinting in Indoor WLAN Environments
Abstract
Positioning in indoor wireless environments is growing rapidly in importance and gains commercial interests in context-awareness applications. The essential challenge in localization is the severe fluctuation of receive signal strength (RSS) for the mobile client even at a fixed location. This work explores the major noisy source resulted from the multipath in an indoor wireless environment and presents an advanced positioning architecture to reduce the disturbance. Our contribution is to propose a novel approach to extract the robust signal feature from measured RSS which is provided by IEEE 802.11 MAC software so that the multipath effect can be mitigated efficiently. The dynamic multipath behavior, which can be modeled by a convolution operation in the time domain, can be transformed into an additive random variable in the logarithmic spectrum domain. That is, the convolution process becomes a linear and separable operation in the logarithmic spectrum domain and then can be effectively removed. To our best knowledge, this work is the first to enhance the robustness to a multipath fading condition, which is common in the environments of an indoor wireless LAN (WLAN) location fingerprinting system. Our approach is conceptually simple and easy to be implemented for practical applications. Neither a new hardware nor an extra sensor network installation is required. Both analytical simulation and experiments in a real WLAN environment demonstrate the usefulness of our approach to significant performance improvements. The numerical results show that the mean and the standard deviation of estimated error are reduced by 42% and 29%, respectively, as compared to the traditional maximum likelihood based approach. Moreover, the experimental results also show that fewer training samples are required to build the positioning models. This result can be attributed to that the location related information is effectively extracted by our algorithm.
Year
DOI
Venue
2008
10.1109/TWC.2008.070373
IEEE Transactions on Wireless Communications
Keywords
Field
DocType
novel algorithm,advanced positioning architecture,time domain,logarithmic spectrum domain,indoor wlan environments,wlan,indoor wireless environment,multipath fading condition,ieee 802.11,dynamic multipath behavior,maximum likelihood estimation,fading channels,mobility management (mobile radio),location fingerprinting,multipath channels,indoor wireless lan location fingerprinting system,maximum likelihood based approach,receive signal strength,ieee 802.11 mac software,multipath,fixed location,multipath fingerprinting,additive random variable,indoor wireless environments,multipath effect,indoor wireless lan,location estimation,wireless lan,mobile client,novel approach,indoor radio,localization,fingerprint recognition,robustness,software measurement,access control,convolution,wireless communication,numerical simulation,noise measurement,random variables,maximum likelihood,convolution operator,multipath fading,ieee 802 11,spectrum,standard deviation,algorithm,noise,fluctuations,sensor array,sensor network,fading,computer architecture,implementation,logarithmic function,random variable,noise reduction
Multipath propagation,Time domain,Wireless,IEEE 802.11,Fading,Sensor array,Algorithm,Computer network,Real-time computing,Robustness (computer science),Wireless sensor network,Mathematics
Journal
Volume
Issue
ISSN
7
9
1536-1276
Citations 
PageRank 
References 
69
2.71
36
Authors
3
Name
Order
Citations
PageRank
Shih-Hau Fang153933.99
T. Lin272467.09
Kun-Chou Lee3693.05