Fast and Precise Direction of Arrival Estimation Based on Space and Frequency Division Multiple Access

This paper introduces a cost-effective method for estimating the range and direction of arrival (DoA). The method is based on the received signal strength indicator and uses a single anchor node. Using space division multiple access through an anchor node with a switched beam front-end, the DoA of a mobile node is determined using a maximum likelihood criterion, guided by the expected signal distribution for a link between the anchor and the node. To enhance the robustness of the approach, two distinct DoA estimation algorithms operating at four frequencies are combined. The proposed method enables low-cost absolute position estimation, making it particularly suitable for wireless sensor networks and IEEE 802.11n/ac-compliant networks. The experimental results validate the effectiveness of the method, demonstrating a mean error of 2. 7 5° and approximately 9 0% localization coverage within 5.2° in a typical home environment of 38 ∼m2. These findings confirm that the proposed system offers an affordable solution without the need of a multi-anchor setup.