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公开(公告)号：US5440313A
公开(公告)日：1995-08-08
申请号：US067947
申请日：1993-05-27
IPC分类号： G01R31/28 , G01S19/05 , G01S19/11 , G01S19/21 , G01S19/29 , G01S19/46 , G04G7/02 , H03L7/00 , H03L7/08 , H04B7/185 , G04B18/00 , H04L7/04
CPC分类号： H03L7/08 , G01R31/2841 , G04R40/06 , H03L7/00
摘要： A GPS-based frequency/time source of the present invention provides an accurate, traceable low cost reference. In particular, the GPS-based frequency/time source includes a GPS receiver, a variable frequency oscillator and a micro processor. The GPS receiver receives and produces as output signals GPS information, whereas the variable frequency oscillator has a frequency control input terminal and produces an output frequency signal, and is coupled to the GPS receiver. The micro processor is coupled to receive the output signals produced by the GPS receiver and produces an error signal indicative of a difference in frequency between GPS synchronized frequency and the output frequency signal of the variable frequency oscillator. Circuitry is responsive to the error signal to produce an electronic frequency control signal, which is applied to the frequency control input of the variable frequency oscillator so as to cause the difference in frequency to be reduced. In this manner, a low cost oscillator may be employed in such a way as to produce a very accurate output frequency signal.
摘要翻译： 本发明的基于GPS的频率/时间源提供了准确的，可追踪的低成本参考。 特别地，基于GPS的频率/时间源包括GPS接收机，可变频率振荡器和微处理器。 GPS接收机接收并产生GPS信息作为输出信号，而可变频率振荡器具有频率控制输入端并产生输出频率信号，并耦合到GPS接收机。 微处理器被耦合以接收由GPS接收器产生的输出信号，并产生指示GPS同步频率与可变频率振荡器的输出频率信号之间的频率差的误差信号。 电路响应于误差信号以产生电子频率控制信号，该电子频率控制信号被施加到可变频率振荡器的频率控制输入端，以便降低频率差。 以这种方式，可以采用低成本振荡器来产生非常精确的输出频率信号。
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2.发明授权Method and system for conserving battery reserves in a navigation receiver by slowing and/or stopping the system clock during low demand 失效用于通过在低需求期间减慢和/或停止系统时钟来节省导航接收器中的电池储备的方法和系统
公开(公告)号：US5949812A
公开(公告)日：1999-09-07
申请号：US764480
申请日：1996-12-12
申请人： Paul F. Turney , David C. Westcott
发明人： Paul F. Turney , David C. Westcott
CPC分类号： G01S19/34
摘要： A battery-operated navigation satellite receiver with an antenna, a radio frequency stage, a down-converter, a digital signal processor and a microcomputer for demodulating L-band microwave carrier frequency spread spectrum transmissions from orbiting navigation satellites that each use their own unique pseudo-random number spreading code. The digital signal processor and a microcomputer each receive system clocks that can be varied in steps from full-speed down to any number of fractions including zero, or full stop. The system clocks to the digital signal processor and a microcomputer are lowered during periods of little or no acquisition or navigation activity. Scheduled updates, communication traffic, user activity, etc., are used to ramp the system clocks back up when the processing load demands it, e.g., when the tasks become CPU-bound at the current clock speed or when a particular task is predetermined to need the full processing speed capability of a particular navigation receiver. The slower system clocks have a direct correspondence with lowered power consumption demands by the digital signal processor and a microcomputer.
摘要翻译： 一种具有天线，射频级，下变频器，数字信号处理器和微型计算机的电池供电的导航卫星接收机，用于解调轨道导航卫星的L波段微波载波频谱扩展频谱，每个导频卫星使用自己独特的伪 随机码扩展码。 数字信号处理器和微型计算机都接收系统时钟，可以从全速下降到包括零或全停的任意数量的分数。 系统时钟到数字信号处理器和微型计算机在很少或没有采集或导航活动期间降低。 计划更新，通信流量，用户活动等用于在处理负载要求时对系统时钟进行斜坡升级，例如，当任务以当前时钟速度或特定任务预定为CPU限制时 需要特定导航接收机的全部处理速度能力。 较慢的系统时钟与数字信号处理器和微型计算机的降低的功耗要求直接对应。
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3.发明授权Fast acquisition of spread-spectrum signals by dynamically varying spacing of search bins 失效通过动态变化搜索箱的间距来快速获取扩频信号公开(公告)号：US06366599B1
公开(公告)日：2002-04-02
申请号：US09040521
申请日：1998-03-16
IPC分类号： H04L2730
摘要： A Global Positioning System (GPS) receiver employs variable spacing of Doppler offset bins and code offset bins when acquiring a P(Y) code, to improve signal acquisition characteristics with respect to a search region having a plurality of Doppler offset bins and code offset bins. The receiver includes an acquisition module in which an input signal representative of a received P(Y) code is received and applied to a first programmable rate mixer. An output of the first programmable rate mixer is applied to a combiner, which selectively combines samples of the input signal based on a control input to dynamically determine the spacing of the code offset bins. An output of the combiner is normalized and applied to a correlation unit, which generates correlation measures of the received P(Y) code and a locally generated P(Y) code. A signal representative of the correlation measures is applied separately to each of a set of programmable rate mixers and mixed with separate mixing signals. The spacing of the Doppler offset bins is dynamically determined by controlling the rates of the mixing signals.
摘要翻译： 全球定位系统（GPS）接收机在获取P（Y）码时采用多普勒偏移箱和码偏移箱的可变间距，以改善相对于具有多个多普勒偏移箱和码偏移箱的搜索区域的信号采集特性 。 接收机包括采集模块，其中接收表示接收的P（Y）码的输入信号并将其应用于第一可编程速率混频器。 第一可编程速率混合器的输出被施加到组合器，组合器基于控制输入选择性地组合输入信号的样本，以动态地确定码偏移仓的间隔。 合成器的输出被归一化并应用于相关单元，该相关单元产生接收到的P（Y）码和本地生成的P（Y）码的相关度量。 表示相关性测量的信号分别应用于一组可编程速率混合器中的每一个并与单独的混合信号混合。 通过控制混合信号的速率来动态地确定多普勒偏移箱的间隔。
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公开(公告)号：US06298083B1
公开(公告)日：2001-10-02
申请号：US09307255
申请日：1999-05-04
IPC分类号： H04L2730
摘要： A Global Positioning System (GPS) receiver includes multiple correlation segments that can operate in parallel. Each correlation segment has a separate set of accumulators associated with it, embodied in random access memory (RAM). In each of the correlation segments, correlation data associated with an input code and a reference code are generated. The multiple correlation segments are cross-coupled, so that correlation data generated in each correlation segment are added to correlation data generated in each other correlation segment. The combined correlation data in each correlation segment are stored in the accumulators of each corresponding correlation segment, such that the accumulators of only one correlation segment are accessed at a time, reducing power consumption resulting from accessing RAM.
摘要翻译： 全球定位系统（GPS）接收机包括可并行操作的多个相关段。 每个相关段具有与之相关的一组单独的累加器，体现在随机存取存储器（RAM）中。 在每个相关段中，生成与输入代码和参考代码相关联的相关数据。 多个相关段被交叉耦合，使得在每个相关段中产生的相关数据被添加到彼此相关段中生成的相关数据。 每个相关段中的组合相关数据被存储在每个对应的相关段的累加器中，使得一次只访问一个相关段的累加器，从而减少访问RAM造成的功耗。
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