Design Of Pseudolites Pulsed Signals And Compatibility Analysis

Pseudolites have the capability to augment the positioning boundary and accuracy of navigation system. Aiming at assisting to BeiDou Navigation,based on signal transmitting of pseudolites and detailed analysis of peculiarities of pseudolites signals,pulsed signals transmitting is proposed. The compatibility between navigation signals and pseudolites and among multiple pseudolites signals are also discussed. Simulation experiments and practice tests are performed. The results show that pulsed signals can help pseudolite be complement to BeiDou Navigation System effectively. Pseudolites pulsed signals have the capability to solve the near-far problem. The compatibility arithmetic can solve compatibility problem between navigation signals and pseudolites signals. The main content includes the following aspects:Firstly,concept of pseudolites?types of pseudolites and applications of pseudolites are discussed, key problems of signal desigining are proposed,including signal interference?near-far problem and compatibility between navigation signals and pseudolites signals, which determines the research direction.Secondly,designs of pseudolites are proposed,including frequency design?expanding frequency codes design and pulse modulation design,and it makes sure that pulse modulation is necessary in this paper. Theory of opposing near-far problem is proposed. Power loss and duty cycles are simulated. Using receiver to capture pulse signals proves that pulse modulation is right and feasible.Thirdly, aiming at solving the problem like the compatibility problem between navigation signals and pseudolites signals and among multiple pseudolites signals,compatibility arithmetic is proposed. Software and simulation processing of compatibility are also introducing. Compatibility simulation proves that the compatibility arithmetic is correct.Finally, minimal and integrated pseudolite experimental platform is introduced, practice test on pseudolites signal transmitting equipment is performed in real condition,verifying the characteristics of signal propagation. It proves that pulse signals have the capability to solve the near-far problem and compatibility problem. Pulsed signal is more outstanding than continuous signal.