发明名称 |
PROCESS FOR SUB-MICROSECOND TIME TRANSFER USING WEAK GPS/GNSS SIGNALS |
摘要 |
Sub-microsecond time transfer in a GPS/GNSS receiver using a weak GPS/GNSS signal is provided. The digitized complex baseband signal and the generated PN code are cross-correlated for each code period so as to output a complex correlation value at each code epoch of the generated PN code, where a sequence of the output correlation values form a data stream representing the navigation message. Bit synchronization generates bit sync pulses at bit boundaries. The location of a target segment having a known sequence at a known bit location in the navigation message is detected by searching through a plurality of subframes and accumulating search results for the plurality of subframes. Transmission time of the target segment is determined from the detected location of the target segment, with a certain time ambiguity. Accurate local time is determined by solving the time ambiguity using approximate time obtained from an external source. |
申请公布号 |
WO2009079380(A2) |
申请公布日期 |
2009.06.25 |
申请号 |
WO2008US86613 |
申请日期 |
2008.12.12 |
申请人 |
MAGELLAN SYSTEMS JAPAN, INC.;WEILL, LAWRENCE R. |
发明人 |
WEILL, LAWRENCE R. |
分类号 |
G01S19/24;H04B7/08 |
主分类号 |
G01S19/24 |
代理机构 |
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代理人 |
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主权项 |
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地址 |
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