BOC(1,1)信号的自适应捕获.pdfVIP

第 30 卷 　第 6 期 电 子 器 件 Vol. 30 　No . 6 20 07 年 12 月 　　　 Ch inese J ou r nal Of Elect ro n D evices 　　 D ec . 20 07 3 An Adap t ive Ac uisit ion Algor it hm f or BO C( 1 , 1) B A Xi a o2hu i , L I J in2hai , C H EN J i e ( Chi n a Insti tute of mic r oelec tr onics , Chin ese Aca demy of Sci ences , 3 # Be i Tu Cheng West Roa d , Cha oy ang D ist ri ct , Beij i ng 100029 , Chin a) Abstr act :BOC mo dul ation w ill be u sed i n GP S mo dernization an d Galileo N avigat ion Sat el li te Sy ste m . This mo dulate d si gnal in duces bet ter t racki ng i n whit e no ise a nd bet te r i n her ent mul tip at h miti gation comp ar ed t o t he sp readi ng co de alone . However , it al so mak es ac ui sit io n mor e challen gin g an d t r ackin g p oten tially am biguou s due to it s mult ipl e p eak au to corr elat ion fu nction . A sy nt h esized lo cal corr elation f unction is p r esen ted b y J ulien , which co mp letely r emove s t he si de2peak t h reat an d al low s clean ac ui si tion a nd t rack2 in g of an y BOC (n ,n) signal while k eep i ng t h e same sh arp corr elation main p ea k . Conse uent ly , it do es not nee d t o c heck if t r ackin g i s done on t he mai n p eak . A n adap ti ve ac ui sition al gorit hm i s deduced ba sed on J ulien ’s al gorit h m , w hic h can a utomatically cha nge t he t hr e shol d accor di ng to differ en t sa tellite si gnal pow er un der t h e con di tion of i nva riabl e error p roba bili ty of ac ui si tion. Key wor ds :adap tive t h reshol d ;t h e error p robabili ty of ac ui si tion ;BOC ; GP S ; Galileo E EACC :722 0