Abstract
In this paper, the target node localization problems based on hybrid RSS-AOA measurements in both noncooperative and cooperative three-dimensional (3-D) wireless sensor networks (WSNs) are discussed. By using novel error approximate expressions for both received signal strength (RSS) and angle-of-arrival (AOA) measurement models, new estimators based on the least squares (LS) criterion are proposed. These estimators can be transformed into mixed semi-definite programming (SDP) and second-order cone programming (SOCP) problems by applying convex relaxation techniques. In addition, the closed-form Cramer-Rao lower bound (CRLB) of the estimator on hybrid measurements in cooperative WSNs is also derived. Theoretical analysis and simulation results show that the Root Mean Square Error (RMSE) of the proposed hybrid RSS-AOA estimators is lower than that of the discussed estimators in both noncooperative and cooperative cases.
Highlights
Wireless sensor network is a distributed sensor network, which is generally composed of a large number of sensors
The Cramer-Rao lower bound (CRLB) on the Root Mean Square Error (RMSE) of any unbiased estimator is employed as a performance benchmark, and the RMSE is used as the main performance indicator of localization algorithms
In the noncooperative wireless sensor networks (WSNs), the models (1), (2), (3) are used to generate the received signal strength (RSS) and AOA measurements. We assume that both the target and the anchor nodes are randomly deployed in a region of size 15×15×15m3 in each Monte Carlo (Mc) run, the reference distance d0 = 1m, the path loss L0 = 40dB, and the path loss exponent (PLE) is fixed as γ = 2.5, similar to [20], the true PLE
Summary
Wireless sensor network is a distributed sensor network, which is generally composed of a large number of sensors. Q. Qi et al.: RSS-AOA-Based Localization via Mixed Semi-Definite and Second-Order Cone Relaxation in 3-D WSNs the location of the target node. Qi et al.: RSS-AOA-Based Localization via Mixed Semi-Definite and Second-Order Cone Relaxation in 3-D WSNs the location of the target node These methods proposed in [16]–[18] were derived only in noncooperative WSNs. In general, the noncooperative localization method has two disadvantages: 1) only one target node can be identified at a time, and 2) only the information transmitted by anchor nodes within the communication range can be utilized, which limits the application of algorithms in large-scale WSNs. In cooperative approaches, each sensor is required more power transmission and has a great dependence on the network structure [2]. 3) We derive the closed-form CRLB of the estimator on hybrid measurements in cooperative WSNs
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
