一种深空再生复合伪码测距信号的自适应捕获跟踪技术

An Adaptive Acquisition and Tracking Technique of the Composite PN Codes for Deep Space Regenerative Ranging

再生复合伪码非常适合于深空测距。分析了复合伪码的相关特性和典型伪码跟踪环的结构,提出了一种通过相位误差过零检测进行码环带宽自适应调整的算法,进而实现测距信号的自适应捕获和跟踪。仿真结果表明算法能使环路的相位误差方差减小6～7倍。

Regenerative composite PN codes are appropriate for deep space ranging. This paper analyses the cross correlation property of a typical composite PN code and the structure of code tracking loop. Thereafter, an adaptive bandwidth adjustment （ABA） algorithm is proposed, which utilizes zero-traversing rate of loop phase error to acquire the adaptive acquisition and tracking of the composite PN ranging code. Simulation results shows that the variation of the loop phase error was reduced by 6 - 7 times compared to the conventional tracking method without ABA.