Vehicle Positioning and Integrity Monitoring Based on GNSS/5G/IMU Fusion System in Urban Environments

Positioning in the urban environment still faces many problems such as low availability of positioning and uncertain credibility of positioning measurement values. 3GPP introduces Positioning Reference Signal (PRS) in the communication system, which provides a new idea for positioning in urban environment. The dedicated and flexible PRS configuration, combined with the advantages of 5G large-scale array antenna and large bandwidth, makes the cellular network signal an ideal source for navigation, and is expected to be an effective supplement to the Global Navigation Satellite System (GNSS). With the increasing demand for secure and trusted navigation services, integrity has become a key indicator to evaluate navigation performance. This paper mainly focuses on the integrity monitoring algorithm based on GNSS/5G/IMU fusion system. First, we introduce the error sources and distributions of 5G positioning technology. Then, we derive the relationship between integrity algorithms for position and measurement domain detection in extended Kalman filter, proposing a dual-check multiple fault detection and exclusion algorithm that balances efficiency and accuracy. We use GNSS data, IMU data collected in typical urban environment and 5G PRS simulation data generated based on 3GPP standard for experimental evaluation. The results show the value of 5G positioning technology, and verify its effectiveness in alleviating the problem of positioning availability and credibility in urban areas. The proposed GNSS/5G/IMU fusion positioning system has the ability of high-precision positioning and integrity monitoring in urban environment.