计算机工程与应用
計算機工程與應用
계산궤공정여응용
COMPUTER ENGINEERING AND APPLICATIONS
2014年
12期
198-201
,共4页
时延控制%卫星导航系统%多普勒补偿%可变分数阶延迟滤波器
時延控製%衛星導航繫統%多普勒補償%可變分數階延遲濾波器
시연공제%위성도항계통%다보륵보상%가변분수계연지려파기
delay control%Global Navigation Satellite Systems(GNSS)%Doppler compensation%variable fractional delay filter
针对高动态或者弱信号条件下,伪码多普勒对卫星导航系统信号捕获的影响将会凸显,导致捕获性能明显降低的问题,提出了一种基于时延控制的码多普勒补偿方法,利用数字延迟滤波器来补偿码多普勒引入的本地码和接收信号的相位不匹配。同时,给出了包括码多普勒补偿在内的新的卫星导航系统信号捕获结构。仿真结果表明:新方法能够很好地进行码多普勒补偿,采用三阶Farrow结构的分数延迟滤波器就可以使捕获损耗降低到0.3 dB以下。
針對高動態或者弱信號條件下,偽碼多普勒對衛星導航繫統信號捕穫的影響將會凸顯,導緻捕穫性能明顯降低的問題,提齣瞭一種基于時延控製的碼多普勒補償方法,利用數字延遲濾波器來補償碼多普勒引入的本地碼和接收信號的相位不匹配。同時,給齣瞭包括碼多普勒補償在內的新的衛星導航繫統信號捕穫結構。倣真結果錶明:新方法能夠很好地進行碼多普勒補償,採用三階Farrow結構的分數延遲濾波器就可以使捕穫損耗降低到0.3 dB以下。
침대고동태혹자약신호조건하,위마다보륵대위성도항계통신호포획적영향장회철현,도치포획성능명현강저적문제,제출료일충기우시연공제적마다보륵보상방법,이용수자연지려파기래보상마다보륵인입적본지마화접수신호적상위불필배。동시,급출료포괄마다보륵보상재내적신적위성도항계통신호포획결구。방진결과표명:신방법능구흔호지진행마다보륵보상,채용삼계Farrow결구적분수연지려파기취가이사포획손모강저도0.3 dB이하。
Code Doppler should be compensated under high dynamic or weak signal conditions during Global Navigation Satellite Systems(GNSS)signal acquisition, which will lead to unacceptable acquisition gain loss. Code Doppler is com-pensated by delay control, including integer delay and fractional delay. Its implementation within GNSS signal acquisition based on integer delay lines and the variable fractional delay filter is proposed. The simulation results show that the new method has a perfect performance of compensating code Doppler, and detection loss can be reduced to less than 0.3 dB with a 4th-order fractional delay filter realized by FARROW structure.