电讯技术
電訊技術
전신기술
TELECOMMUNICATIONS ENGINEERING
2015年
8期
890-894
,共5页
GNSS接收机%锁相环%环路滤波器%最优环路带宽
GNSS接收機%鎖相環%環路濾波器%最優環路帶寬
GNSS접수궤%쇄상배%배로려파기%최우배로대관
GNSS receiver%phase-locked loop%loop filter%optimal loop bandwidth
锁相环环路带宽值的选取对于锁相环的跟踪误差性能有重要影响。基于全球卫星导航系统( GNSS)接收机中常用锁相环结构与数学模型,首先介绍了锁相环及其重要组成部分环路滤波器的结构和原理,然后分析了环路带宽的取值对锁相环两个最重要的误差源———环路热噪声误差和晶振阿伦偏差的影响,给出了低动态下使锁相环总的跟踪误差最小的最佳环路带宽的理论表达式。对基于由现场可编程门阵列( FPGA)芯片、温补晶振和模/数接口电路构建的实际硬件接收机平台进行了验证,结果表明:当根据最佳环路带宽的理论表达式取环路带宽值时,锁相环的跟踪误差最小。所推得的理论表达式不仅可以应用于GNSS接收机,也适用于一般的载波跟踪环设计。
鎖相環環路帶寬值的選取對于鎖相環的跟蹤誤差性能有重要影響。基于全毬衛星導航繫統( GNSS)接收機中常用鎖相環結構與數學模型,首先介紹瞭鎖相環及其重要組成部分環路濾波器的結構和原理,然後分析瞭環路帶寬的取值對鎖相環兩箇最重要的誤差源———環路熱譟聲誤差和晶振阿倫偏差的影響,給齣瞭低動態下使鎖相環總的跟蹤誤差最小的最佳環路帶寬的理論錶達式。對基于由現場可編程門陣列( FPGA)芯片、溫補晶振和模/數接口電路構建的實際硬件接收機平檯進行瞭驗證,結果錶明:噹根據最佳環路帶寬的理論錶達式取環路帶寬值時,鎖相環的跟蹤誤差最小。所推得的理論錶達式不僅可以應用于GNSS接收機,也適用于一般的載波跟蹤環設計。
쇄상배배로대관치적선취대우쇄상배적근종오차성능유중요영향。기우전구위성도항계통( GNSS)접수궤중상용쇄상배결구여수학모형,수선개소료쇄상배급기중요조성부분배로려파기적결구화원리,연후분석료배로대관적취치대쇄상배량개최중요적오차원———배로열조성오차화정진아륜편차적영향,급출료저동태하사쇄상배총적근종오차최소적최가배로대관적이론표체식。대기우유현장가편정문진렬( FPGA)심편、온보정진화모/수접구전로구건적실제경건접수궤평태진행료험증,결과표명:당근거최가배로대관적이론표체식취배로대관치시,쇄상배적근종오차최소。소추득적이론표체식불부가이응용우GNSS접수궤,야괄용우일반적재파근종배설계。
The bandwidth value of phase-locked loop ( PLL ) plays an important role in determining the tracking error performance of PLL. Firstly, the structure and principle of PLL and its important compo-nent—loop filter are introduced based on normal PLL structure and mathematical model of Global Naviga-tion Satellite System( GNSS) receiver. And then the effects of loop bandwidth value on two most important error sources of PLL( PLL loop thermal noise and Allen variance of the oscillator) are analyzed. The theo-retical expression of the optimal loop bandwidth value to minimize the total PLL tracking error in low dy-namic conditions is proposed. And it is verified on the practical hardware receiver platform composed of Field-Programmable Gate Array( FPGA) chip,Temperature Compensate Xtal Oscillator( TCXO) and A/D interface circuits. The results show that PLL tracking error is minimal at the value according to the pro-posed theoretical expression of the optimal loop bandwidth. The theoretical expression can be applied to both GNSS receiver and normal carrier tracking loop design.