Literature indicates that spatial diversity can be utilized to compensate channel uncertainties such as multipath fading. Therefore, in this paper, spatial diversity is exploited for locating stationary and mobile objects in the indoor environment. First, space diversity technique is introduced for small scale motion and temporal variation compensation of received signal strength and it is demonstrated analytically that it enhances location accuracy. Small scale motion refers to movements of the transmitter and/or the receiver of the order of sub-wavelengths while temporal effects refer to environmental variations with time. A novel metric is introduced for selection combining in order to improve location accuracy through the addition of spatial diversity upon two available location determination schemes. The results are evaluated experimentally against single antenna system for reception by using low cost wireless RF devices such as motes. Alternatively, the impact of the number of location determination devices in a probabilistic WLAN network based on pre-profiling of signal strength is analyzed and it is demonstrated analytically that location accuracy improves with the number of receivers used. Spatial diversity in terms of the antenna spacing of 2lambda is evaluated and shown to provide a reduction in location determination error between 30 and 40% when compared to a single antenna system.

Meeting Name

32nd IEEE Conference on Local Computer Networks, 2007. LCN 2007


Electrical and Computer Engineering

Second Department

Computer Science


Air Force Research Laboratory (Wright-Patterson Air Force Base, Ohio)

Keywords and Phrases

WLAN Location Determination; Geo-Location; Location Accuracy; Spatial Diversity

Document Type

Article - Conference proceedings

Document Version

Final Version

File Type





© 2007 Institute of Electrical and Electronics Engineers (IEEE), All rights reserved.