IS-GPS-200F (811524), страница 5
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An expanded set of 26 C/A-code PRN sequences are identified in Table 3Ib using “G2 Delay” and “Initial G2 Setting” which is not the same as the method used in Table 3-Ia. The two-tapcoder implementation method referenced and used in Table 3-Ia is not used in Table 3-Ib due to its limitation ingenerating C/A-code sequences.
The “G2 Delay” specified in Table 3-Ib may be accomplished by using the “InitialG2 Setting” as the initialization vector for the G2 shift register of Figure 3-9. Assignment of these expanded codephase segments by SV ID number is given in Table 3-Ib. Additional PRN C/A-code sequences with assigned PRNnumbers are provided in Section 6.3.7.1, Table 6-I.3.2.1.4 L2 CM-Code (IIR-M, IIF, and subsequent blocks). The PRN L2 CM-code for SV ID number i is a rangingcode, CM,i(t), which is 20 milliseconds in length at a chipping rate of 511.5 Kbps. The epochs of the L2 CM-codeare synchronized with the X1 epochs of the P-code. The CM,i(t) sequence is a linear pattern which is short cycledevery count of 10230 chips by resetting with a specified initial state. Assignment of initial states by GPS PRNsignal number is given in Table 3-IIa.3.2.1.4.1 Expanded L2 CM Code (GPS III).
An expanded set of 26 L2 CM-Code PRN sequences are identified withassignment of initial states by SV ID number in Table 3-IIb. Additional PRN L2 CM-code sequence pairs areprovided in Section 6.3.7.3, Table 6-II.3.2.1.5 L2 CL-Code (IIR-M, IIF, and subsequent blocks). The PRN L2 CL-code for SV ID number i is a rangingcode, CL,i(t), which is 1.5 seconds in length at a chipping rate of 511.5 Kbps.
The epochs of the L2 CL-code aresynchronized with the X1 epochs of the P-code. The CL,i(t) sequence is a linear pattern which is generated using thesame code generator polynomial as the one used for CM,i(t). However, the CL,i(t) sequence is short cycled byresetting with a specified initial state every code count of 767250 chips. Assignment of initial states by GPS PRNsignal number is given in Table 3-IIa.3.2.1.5.1 Expanded L2 CL-Code (GPS III). An expanded set of 26 L2 CL-Code PRN sequences are identified withassignment of initial states by SV ID number in Table 3-IIb. Additional PRN L2 CL-code sequence pairs areprovided in Section 6.3.7.3, Table 6-II.5IS-GPS-200F21 Sep 2011Table 3-Ia.SVIDNo.GPS PRNSignalNo.1234567891011121314151617181912345678910111213141516171819****Code Phase Assignments (sheet 1 of 2)Code DelayChipsC/APCode Phase SelectionC/A(G2i)***2345121232356789123⊕⊕⊕⊕⊕⊕⊕⊕⊕⊕⊕⊕⊕⊕⊕⊕⊕⊕⊕6789910891034678910456(X2i)123456789101112131415161718195678171813914014125125225425525625725846947047112345678910111213141516171819First10 ChipsOctal*C/AFirst12 ChipsOctalP144016201710174411331455113114541626150416421750176417721775177611561467163344444000422243334377435543444340434243434343In the octal notation for the first 10 chips of the C/A code as shown in this column, the firstdigit (1) represents a "1" for the first chip and the last three digits are the conventionaloctal representation of the remaining 9 chips.
(For example, the first 10 chips of the C/Acode for PRN Signal Assembly No. 1 are: 1100100000).**C/A Codes for 34 and 37 are identical.The two-tap coder utilized here is only an example implementation that generates a limitedset of valid C/A codes.⊕ = "exclusive or"⊕ = "exclusive or"NOTE #1: The code phase assignments constitute inseparable pairs, each consisting of a specificC/A and a specific P code phase, as shown above.6IS-GPS-200F21 Sep 2011Table 3-Ia.SVIDNo.GPS PRNSignalNo.2021222324252627282930313265666768692021222324252627282930313233***34**353637*******Code Phase Assignments (sheet 2 of 2)Code DelayChipsC/APCode Phase SelectionC/A(G2i)****456145678123454124⊕⊕⊕⊕⊕⊕⊕⊕⊕⊕⊕⊕⊕⊕⊕⊕⊕⊕7893678910678910107810(X2i)202122232425262728293031323334353637472473474509512513514515516859860861862863950947948950202122232425262728293031323334353637First10 ChipsOctal*C/AFirst12 ChipsOctalP17151746176310631706174317611770177411271453162517121745171311341456171343434343In the octal notation for the first 10 chips of the C/A code as shown in this column, the firstdigit (1) represents a "1" for the first chip and the last three digits are the conventionaloctal representation of the remaining 9 chips.
(For example, the first 10 chips of the C/Acode for PRN Signal Assembly No. 1 are: 1100100000).**C/A codes 34 and 37 are identical.*** PRN sequence 33 is reserved for other uses (e.g. ground transmitters).The two-tap coder utilized here is only an example implementation that generates a limitedset of valid C/A codes.⊕ = "exclusive or"NOTE #1: The code phase assignments constitute inseparable pairs, each consisting of a specificC/A and a specific P code phase, as shown above.7IS-GPS-200F21 Sep 2011Table 3-Ib. Expanded Code Phase Assignments (III and subsequent blocks only)SVIDNo.7071727374757677787980818283848586878889909192939495GPSPRNSignalNo.3839404142434445464748495051525354555657585960616263Code Phase SelectionG2Initial G2X2DelaySettingDelay(Chips)(Octal)*(Chips)6700171103054129117143191151467916515225010366250543794615068638106591611564101001136511554154112280132713710171614709163515775100216864101517558166618220017719397135320550426218980227227590506233670336242991333251018174526P-codeRelativeAdvance(Hours) **P1(t+24)P2(t+24)P3(t+24)P4(t+24)P5(t+24)P6(t+24)P7(t+24)P8(t+24)P9(t+24)P10(t+24)P11(t+24)P12(t+24)P13(t-24)P14(t+24)P15(t+24)P16(t+-24)P17(t+24)P18(t+24)P19(t+24)P20(t+24)P21(t+24)P22(t+24)P23(t+24)P24(t+24)P25(t+24)P26(t+24)First10 ChipsOctal*C/A17601236006306260126167412340271071202130412023604500061014207750762011116000424135115501271144104440032First12 ChipsOctalP33733757754554404402402302332337337537543544744014026423103326377135567405146064121067261171665611056660* In the octal notation for the first 10 chips of the C/A-code or the initial settings as shown in thistable, the first digit (1/0) represents a "1" or “0”, respectively, for the first chip and the lastthree digits are the conventional octal representation of the remaining 9 chips(For example, the first 10 chips of the C/A code for PRN Signal Assembly No.
38 are: 1111110000).**Pi(t+N): P-code sequence of PRN number i shifted by N hours. See Section 3.3.2.1.NOTE #1: The code phase assignments constitute inseparable pairs, each consisting of a specificC/A and a specific P code phase, as shown above.NOTE #2: PRNs 38-63 are required per this Table if a manufacturer chooses to include these PRNsin their receiver design.8IS-GPS-200F21 Sep 2011Table 3-IIa.SVIDNo.12345678910111213141516171819GPSPRNSignalNo.12345678910111213141516171819Code Phase Assignments (IIR-M, IIF, and subsequent blocks only) (sheet 1 of 2)Initial Shift Register State (Octal)L2 CML2 CL742417664756014035002747144066265724601403471703232733124510070617316361047541621733031046713512145024437606021264003230655351001314400222021506540264026205521705064022144624145772506610362220360016710406104001143345053023326652521276206124777015563374561522076023163525117776450606516355003037343046515565671511621605402220002576207525163451End Shift Register State (Octal)L2 CM *L2 CL **552566002034445034723443711511222013463055213667044524652322653505703344520302775244205506236174002654305531435070571630431251234043417535540745043056734731304103412120105267724236167516066771756405047202624052770433761743665133015726610611511352150323051266046305611373504676773272572634731320771631326563231516360030367366713543613232674654* Short cycled period = 10230** Short cycled period = 767250NOTE: There are many other available initial register states which can be used for other signaltransmitters including any additional SVs in future.9IS-GPS-200F21 Sep 2011Table 3-IIa.SVIDNo.202122232425262728293031326566676869GPSPRNSignalNo.202122232425262728293031323334353637Code Phase Assignments (IIR-M, IIF, and subsequent blocks only) (sheet 2 of 2)Initial Shift Register State (Octal)L2 CML2 CLEnd Shift Register State (Octal)L2 CM *L2 CL **120161274044023533724744327045743577741201660700274134010247261713433445737324162311627434710452007722462133050172213500653703755077436136717361756675453435506112365636111143324657110766462602405203177735650630177560653467107406576630221777100773266673100010710431037132624127475154624012275636742644341556514260662133501670266527765006760703501474556743747443615534726763621420720727474700521043222567263132765304746332245102300466255231716437661701717047302222614207561123307240713073641733155730125345000316074171313614001523662023457250330733254625055726476524061602066031012412526705144501615373171041637664100107264634251723257012032703702423* Short cycled period = 10230** Short cycled period = 767250NOTE: There are many other available initial register states which can be used for other signaltransmitters including any additional SVs in future.10IS-GPS-200F21 Sep 2011Table 3-IIb.SVIDNo.7071727374757677787980818283848586878889909192939495GPSPRNSignalNo.3839404142434445464748495051525354555657585960616263Expanded Code Phase Assignments (III and subsequent blocks only)Initial Shift Register State (Octal)L2 CML2 CL771353753226107701022025110402466344752566114702011164041216771047457275266333164713167356060546335355173035617201036157465571767360553023127030431343777747317317045706125002744276060036467217744147603340174326616775063240065111460621***101232630132525726315216367377046065655351360435776513744242321024346717562646415731455342723352536000013134011566642475432222463506741617127534026050332733774235751477772417631550052247456560404163417751005004302173715005045001154457End Shift Register State (Octal)L2 CM *L2 CL **453413162637760505612775765136315217264252240113027466774524245161633757603442167213146546721323277207073253130632332606370621330610170744312067154235152525024652535207413655375733316666241525453337114323414755234667526032633602375063463624741673421367703006075746566507444022714136645570645752300656113341015705106002757466100273370304463615054341657333276704750231416541445326316216573007360406112114774042303316353150521044511154244410144562324657027501534521240373Short cycled period = 10230Short cycled period = 767250.NOTE #1: There are many other available initial register states which can be used for other signaltransmitters including any additional SVs in future.NOTE #2: PRNs 38-63 are required per this Table if a manufacturer chooses to include these PRNs intheir receiver design.11IS-GPS-200F21 Sep 20113.2.1.6 Non-Standard Codes.
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