地基伪卫星信号发射分集技术研究

伪卫星可提高卫星导航系统在遮蔽环境中的信号覆盖性。地基伪卫星信号仰角低,将导致更为严重的多径影响,不仅会造成较大的伪距测量值误差,而且由多径产生的功率相消会导致信噪比不足,导致接收机的失锁,造成伪卫星信号不可用。针对多径导致的地基伪卫星信号不可用影响,研究信号发射分集技术在地基伪卫星中的应用,对几种典型的发射分集方式进行理论分析和性能仿真。仿真结果表明,通过信号发射分集实现多导航信号相互补充,提高了覆盖区域内地基伪卫星信号的可用性。

Research on Transmit Diversity Techniques for Ground-based Pseudolites

Pseudolites provide extra signal to improve the navigation signal coverage in obstructed environment.Low signal elevation of the pseudolites leads to more serious multipath effect which may cause more pseudo range measurement error and power loss that leads to lower SNR(signal-to-noise ratio),causing loss of signal lock in receivers and making the pseudolite signals useless.To address this issue,a brief introduction to the application of transmit diversity techniques for pseudolites is presented,and a simulation of typical techniques is performed.The simulation results show that the transmit diversity techniques can use signals complementing each other to improve the pseudolites'signal availability.