| The pseudolite technique is not only an advanced satellite navigation augmentation technique, which can improve the stability、reliability and precision of the whole system, but also can build an independent navigation system. The Ultra-Wideband technique has the characteristics of high positioning precision、multipath-resisted ability and good penetrating ability. The thesis focuses on the key technology of navigation and positioning based on pesudolites and UWB. The main contributions are as follows:1. The feasibility of the pseudolite-UWB joint navigation is analyzed, particularly studies the link of the IR-UWB signal. It’s found that under the condition of the frequency concealment criterion of FCC, if we reduce the information rate, the communication distance will increase. And it totally satisfies the need of setting UWB pesudolites near the floor or in the air.2. The performance of the satellite navigation augmentation system based on pesudolites and UWB is simulated. The results show that the system can locate the user without enough navigation satellites in sight. And it can also notablely improve the GDOP value of the system and enhance the positioning precision.3. It proposes a TDOA/AOA joint positioning scheme. Only one fixed station is needed. The AOA information is gotten by the TDOA estimation in the line-of-sight environment. Just by turning the antennas to a suitable angle, the scheme can locate and track the MT. The simulation results show that when the parameters are well set, the scheme can decrease the model error effectively and track the short-distance MT well.4. A NLOS positioning scheme is given. The arrival strongest paths are detected in the nonline-of-sight environment,using the multipath characteristic of IR-UWB signal. Then the scheme uses the TOA/AOA joint method to locate and track the MT. The simulation results show that it can locate and track the short-distance MT effectively just with four fixed stations. |
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