Research On Communication And Navigation Integration Technology Based On 5G Open-source Base Station

Since the completion of the Beidou Global Navigation Satellite System,it has brought great convenience to people’s lives.However,in indoor and underground scenarios,the satellite signal becomes weak due to environmental obstruction,it is difficult for users to get the location information they need.To solve this problem,many experts focus on the integration technology of communication and navigation,and expect to enhance the navigation and positioning system through the mature mobile communication system.5G,as the mainstream of current mobile communication,has become the first choice to enhance navigation and positioning technology.The 5G base stations,as the main components of the5 G network,have become the key to the implementation of communication and navigation integration technology.This thesis utilizes the same type of pseudolite positioning technology as Beidou,integrates 5G open-source base stations with Beidou pseudolite base stations,and enhances positioning while retaining the advantages of 5G.The main work is as follows:1)To solve the problem of deteriorating availability of the Beidou Navigation Satellite System in near-earth environments,a scheme of integrating 5G open-source base stations and pseudolite base stations is proposed.Aiming at the problem of ranging accuracy degradation due to noise,occlusion,and multipath in positioning process of the integrated system,a multiple signal classification time delay estimation algorithm based on frequency domain bidirectional smoothing is proposed.Orthogonal frequency division multiplexing subcarriers are used to form the data-stream,and then bidirectional smoothing is performed on the covariance matrix of the data-stream in the frequency domain.Finally,a multiple signal classification algorithm is used to detect the spatial spectrum by the orthogonality of the signal or noise subspace,and the spatial spectrum is normalized according to the random noise situation,so as to obtain more accurate time delay estimation information.The simulation results show that the improved time delay estimation algorithm has a higher spatial spectral amplitude and narrower main-lobe width,with a minimum time delay estimation interval is 6ns.In a complex environment with a signal-to-noise ratio of-15 d B,the time delay estimation accuracy can reach about 3ns,and the resolution ability is strong,which verifies the effectiveness and superiority of the algorithm.2)To improve the positioning accuracy and robustness of the 5G and pseudolite integrated system,a fault-tolerant adaptive federated Kalman filter fusion algorithm is proposed.The algorithm is based on the federated Kalman filter.Firstly,the local filter is used to denoise and filter the measurement data of the 5G or Pseudolite subsystem to obtain the local optimal estimate.Secondly,the local optimal estimate is detected and processed for outliers.Finally,the main Kalman filter is used to fuse the data after detecting and processing,and obtain the global optimal estimate based on all measurement values.The simulation results show that the improved fault-tolerant adaptive federated Kalman filter fusion algorithm can improve the positioning accuracy of 5G and pseudolite integrated system significantly,and has fault detection and processing capabilities,which enhances the robustness of the system greatly.3)To further verify the communication and positioning capabilities of the 5G and pseudolite integrated system,the test architecture of 5G and pseudolite integrated system is designed.The experimental hardware equipment and software platform is introduced to carry out the experimental test.The capability test of communication and positioning of the5 G and pseudolite integrated system is completed.The test results show that the integrated system of 5G and pseudolite has the advantages of maintaining the maximum 5G communication rate of 655 Mbps,the signal to interference plus noise ratio of 80.36% better than 20 d B,and the reference signal receiving power of better than-90 d B.The positioning can reach sub-meter-level accuracy,and the entire positioning process is continuous and stable without breakpoints,which is better than the current indoor positioning standards.