Investigations on Direction of Arrival and Range Estimation with a Switched Beam Antenna Architecture Implementing Space and Frequency Division Multiple Access

In this paper, we investigate the proof-of-concept of an indoor positioning system, based on the combined use of Space and Frequency Division Multiple Access. This technology permits a very cost-effective estimation of Direction of Arrival as well as the range of a target node, resulting in an actual absolute positioning system. The estimation is the result of a maximum likelihood criteria driven by the expected signal partition for a link between anchor and node operating over four frequency band channels. Experimental validations in a real-life scenario confirm that the proposed single-anchor approach is effective in 2D localization, providing a mean error of 17 cm and a localization area coverage of about 90% below 30 cm within a typical room area size (38 m(2)).