针对闭环大时延的GNSS数字锁相环路设计  

Design of GNSS DPLL with large closed-loop delay

作　　者：汤新华[1,2] 朱鑫敏 滕贤亮 张敏 沈健 TANG Xinhua;ZHU Xinmin;TENG Xianliang;ZHANG Min;SHEN Jian(School of Instrument Science and Engineering,Southeast University,Nanjing 210096,China;Key Laboratory of Micro-inertial Instrument and Advanced Navigation Technology of Ministry of Education,Nanjing 210096,China;State Key Laboratory of Smart Grid Protection and Control,Nari Group Corporation,Nanjing 210096,China)

机构地区：[1]东南大学仪器科学与工程学院,南京210096 [2]微惯性仪表与先进导航技术教育部重点实验室,南京210096 [3]南瑞集团有限公司智能电网保护和运行控制国家重点实验室,南京210096

出　　处：《中国惯性技术学报》2023年第8期790-796,805,共8页Journal of Chinese Inertial Technology

基　　金：国家电网公司总部科技项目(5700-202140340A-0-0-00)。

摘　　要：在GNSS终端方案设计中,跟踪环路闭环大时延将导致传统数字跟踪环路模型与实际模型的偏离,极大限制了归一化噪声带宽的约束极限,从而影响了环路的动态性能及跟踪精度。为解决这一问题,通过分析环路噪声带宽或相干积分时间发生变化对跟踪环路Z域离散模型极点位置的影响,采用参数化根方法设计了数字环路滤波器,实现了高延时情况下数字锁相环路的稳定工作。实验结果表明,相比于传统跟踪环路,在闭环时延100 ms情况下,考虑闭环大时延设计得到锁相环路的归一化噪声带宽能够实现从0.08到1.321的扩展,对于高动态、弱GNSS信号的跟踪及后续导航解算具有重要意义。In the design of GNSS terminal scheme,the large closed-loop delay of tracking loop will lead to the deviation between the traditional digital tracking loop model and the actual model,which greatly restricts the constraint limit of the normalized noise bandwidth,thus affecting the dynamic performance and tracking accuracy of the loop.In order to tackle the issue,the influence of noise bandwidth and coherence integration period on the pole position of the discrete model in Z domain of tracking loop is further analyzed,and a controlled-root method is leveraged to conduct the derivation of the digital loop filter,which achieves stable operation of the digital phase-locked loop(DPLL)under high delay conditions.The experimental results show that compared with the traditional tracking loop,when the closed-loop delay is 100 ms,the normalized noise bandwidth of the proposed DPLL can be extended from 0.08 to 1.321,which is of great significance for the tracking of high-dynamic and weak GNSS signals and the subsequent navigation solution.

关 键 词：GNSS跟踪环路 BT约束 矢量跟踪 参数化根方法 

分 类 号：U666.14[交通运输工程—船舶及航道工程]