tailieunhanh - Báo cáo hóa học: " Correlation-based radio localization in an indoor environment"

Tuyển tập các báo cáo nghiên cứu về hóa học được đăng trên tạp chí hóa hoc quốc tế đề tài : Correlation-based radio localization in an indoor environment | Callaghan et al. EURASIP Journal on Wireless Communications and Networking 2011 2011 135 EURASIP Journal on . http content 2011 1 135 Wireless Communications and Networking a SpringerOpen Journal RESEARCH Open Access Correlation-based radio localization in an indoor environment Thomas Callaghan1 Nicolai Czink2 Francesco Mani3 Arogyaswami Paulraj4 and George Papanicolaou4 Abstract We investigate the feasibility of using correlation-based methods for estimating the spatial location of distributed receiving nodes in an indoor environment. Our algorithms do not assume any knowledge regarding the transmitter locations or the transmitted signal but do assume that there are ambient signal sources whose location and properties are however not known. The motivation for this kind of node localization is to avoid interaction between nodes. It is most useful in non-line-of-sight propagation environments where there is a lot of scattering. Correlation-based node localization is able to exploit an abundance of bandwidth of ambient signals as well as the features of the scattering environment. The key idea is to compute pairwise cross correlations of the signals received at the nodes and use them to estimate the travel time between these nodes. By doing this for all pairs of receivers we can construct an approximate map of their location using multidimensional scaling methods. We test this localization algorithm in a cubicle-style office environment based on both ray-tracing simulations and measurement data from a radio measurement campaign using the Stanford broadband channel sounder. Contrary to what is seen in other applications of cross-correlation methods the strongly scattering nature of the indoor environment complicates distance estimation. However using statistical methods the rich multipath environment can be turned partially into an advantage by enhancing ambient signal diversity and therefore making distance estimation more robust. The main .