An Adaptive Scheduling Strategy of the Dual-frequency and Dual-mode PseudoLite Positioning System in Indoor Dense Multi-path Environments

The PseudoLite technology to be used for indoor precision positioning is one of the research hotspots at present. Under the indoor dense mufti-path propagation environment, the mufti-path effect causes the loss of lock and cycle skipping of the receiver, so that the receiver cannot continuously and stably obtain the carrier phase observation data, which in turn affects the stability and effectiveness of the positioning system work. The GPS+BDS dual-frequency and dual-mode network is adopted in this paper, and a fast algorithm of integer ambiguity and an adaptive scheduling strategy of PseudoLite observation data are proposed. Firstly, the mathematical model of single-difference positioning is established according to the dual-frequency and dual-mode carrier phase observation equation set, and the least squares method is used to realize the fast solving of the integer ambiguity, then analyze and judge the loss of lock and tracking situation of the PseudoLite carrier phase observation channel, and according to the state of each loop in each calendar element, making use of the redundant carrier phase observation data resources, and according to the requirements of positioning solution, adopting the adaptive scheduling strategy to complete the PseudoLite selection and scheduling, so as to ensure that the system is able to continuously and stably locate the satellite.