摘要
为提高全球导航卫星系统(GNSS)的抗干扰能力,要求在不借助于短码辅助的情况下对长码进行直接捕获.传统长码直接捕获算法针对的是正常接收信号.当信号被遮挡或干扰以后将变得十分微弱,此时已有算法将面临严峻挑战.为此,本文提出了一种基于码多普勒补偿的长码捕获算法.该算法根据所搜索的载波频率格进行码多普勒补偿,可以大大延长预检测积分时间从而改善捕获性能.仿真结果表明,新算法能有效减小码多普勒影响,在相干积分时间为1ms非相干累加次数为300情况下,捕获灵敏度可达-183dBW.
To improve the anti-jamming capability of global navigation satellite system （GNSS）, it is required to directly acquire long pseudo-noise （PN） code without the aid of short PN-code. Conventional direct long PN-code acquisition methods target at normal signals. However, when the signals are blocked or interfered, they will become very weak and the methods are inapplicable. To solve the problem, in the study a method based on code-Doppler-compensation is proposed. By compensating code Doppler according to the searched carrier frequency cell, pre-detection integration time is greatly extended and consequently detection performance is significantly improved. Simulation results demonstrate the proposed method is effective to reduce the effect of code Doppler and has detection sensitivity -183 dB W when coherent integration time is 1 ms and non-coherent integration number is 300.
出处
《中国科学：物理学、力学、天文学》
CSCD
北大核心
2010年第5期560-567,共8页
Scientia Sinica Physica,Mechanica & Astronomica
基金
中国博士后科学基金资助项目(编号:2009046370)
关键词
微弱长码信号
GNSS
捕获
码多普勒
捕获性能
week long PN-code
GNSS
acquisition
code Doppler
acquisition performance
