公开(公告)号：US5717403A

公开(公告)日：1998-02-10

申请号：US524083

申请日：1995-09-06

申请人： Frederick Nelson ,  Richard Kai-Tuen Woo ,  Ronald R. Hatch

发明人： Frederick Nelson ,  Richard Kai-Tuen Woo ,  Ronald R. Hatch

IPC分类号： G01S1/00 ,  H03L7/00 ,  G01S5/02

CPC分类号： H03L7/00

摘要： A method and apparatus for synthesizing a stable reference signal of a desired frequency within a spread spectrum receiver is disclosed herein. The spread spectrum receiver is designed for use in conjunction with a global positioning system (GPS) receiver, and operates to receive broadcast differential GPS correction information. The present frequency synthesis technique contemplates generating a sequence of timing signals within the GPS receiver on the basis of GPS satellite signals received thereby, and providing the timing signals to the signal receiver. Within the signal receiver, the signal cycles of a local oscillator occurring between ones of the timing signals are counted. The frequency of the local oscillator is then determined by dividing the counted cycles of the local oscillator by one of the known time intervals. The determined frequency of output signals produced by the local oscillator is then scaled so as necessary to produce the reference signal of desired frequency. This allows precisely controlled reference frequencies to be obtained irrespective of the existence of frequency instability within the local oscillator. In a preferred implementation, the stable reference signals are employed during acquisition of differential GPS correction signals received by the spread spectrum receiver. In particular, the desired reference frequency is incrementally adjusted during the process of searching for and acquiring the exact frequency of the incident differential GPS correction signals. The spread spectrum receiver is disposed to provide differential GPS correction information extracted from the acquired differential GPS correction signals to the GPS receiver.

摘要翻译： 本文公开了一种用于在扩频接收机内合成所需频率的稳定参考信号的方法和装置。 扩频接收机被设计为与全球定位系统（GPS）接收机一起使用，并且操作以接收广播差分GPS校正信息。 本频率合成技术考虑根据由此接收的GPS卫星信号，在GPS接收机内产生定时信号序列，并向定时信号提供信号。 在信号接收器内，对定时信号之间发生的本地振荡器的信号周期进行计数。 然后通过将本地振荡器的计数周期除以已知时间间隔之一来确定本地振荡器的频率。 然后对本地振荡器产生的输出信号的确定频率进行缩放，以便产生所需频率的参考信号。 这允许获得精确控制的参考频率，而不管本地振荡器内是否存在频率不稳定性。 在优选实施例中，在采集由扩频接收机接收的差分GPS校正信号的采集期间采用稳定的参考信号。 特别地，在搜索和获取入射差分GPS校正信号的确切频率的过程中，期望的参考频率被递增地调整。 扩频接收机被设置为提供从所获取的差分GPS校正信号中提取到GPS接收机的差分GPS校正信息。

公开(公告)号：US06259401B1

公开(公告)日：2001-07-10

申请号：US09060399

申请日：1998-04-14

申请人： Richard Kai-Tuen Woo

发明人： Richard Kai-Tuen Woo

IPC分类号： G01S502

CPC分类号： G01S19/22 ,  G01S19/29

摘要： A global positioning system receiver includes an inbound signal terminal to receive an inbound global positioning system signal having an inbound PRN code from a global positing system signal source. A local PRN code generator is configured to generate a local PRN code. A discriminator is coupled to the inbound signal terminal and to the local PRN code generator and configured to compare the inbound signal and the local PRN code and to generate a discriminator signal containing a positive portion and a negative portion. A processor is coupled to the discriminator and configured to receive the discriminator signal to process the discriminator signal to determine a bit code and to determine a distance from the global positing system signal source based on said bit code. In one embodiment, the discriminator includes an acquisition mode configured to acquire the inbound PRN code wherein the discriminator has a first gate width and a tracking mode configured to track the PRN code wherein the discriminator has a second gate width less than the first gate width. Advantages of the invention include improved multipath signal rejection.

摘要翻译： 全球定位系统接收机包括入站信号终端，用于从全局定位系统信号源接收具有入站PRN码的入站全局定位系统信号。 本地PRN代码生成器被配置为生成本地PRN代码。 鉴别器耦合到入站信号终端和本地PRN码发生器，并被配置为比较入站信号和本地PRN码，并产生包含正部分和负部分的鉴别信号。 处理器耦合到鉴别器，并被配置为接收鉴别器信号以处理鉴别器信号以确定位码，并根据所述位码确定与全局定位系统信号源的距离。 在一个实施例中，鉴别器包括获取模式，其被配置为获取入站PRN码，其中鉴别器具有第一栅极宽度，跟踪模式被配置为跟踪PRN码，其中鉴别器具有小于第一栅极宽度的第二栅极宽度。 本发明的优点包括改进的多径信号抑制。

公开(公告)号：US06760393B1

公开(公告)日：2004-07-06

申请号：US09564683

申请日：2000-05-04

申请人： Jalal Alisobhani ,  Donald K. Leimar ,  Richard Kai-Tuen Woo ,  Mark Philip Kaplan

发明人： Jalal Alisobhani ,  Donald K. Leimar ,  Richard Kai-Tuen Woo ,  Mark Philip Kaplan

IPC分类号： H04L700

CPC分类号： H04L27/22 ,  H04B1/707 ,  H04L27/2017 ,  H04L2027/0028 ,  H04L2027/0055

摘要： A communication device includes a transmitter and receiver. The transmitter includes an M-ary encoder configured to generate an M−1 number of distinctive symbols each comprising k bits. M is equal to 2k and k is a positive integer. The transmitter also includes a code generator configured to produce spread spectrum codeword sequences based on the symbols generated by the M-ary encoder and based on a first and a second Gold code polynomials. The transmitter sends a radio signal based on the spread spectrum codeword sequences. The receiver is configured to receive the radio signal. The receiver includes a first shift register configured to receive an input signal generated based on the received radio signal and a second shift register configured to receive and circularly shift a locally generated codeword sequence that is identical to the codeword sequence used to encode the symbols.

摘要翻译： 通信设备包括发射机和接收机。 所述发射机包括M元编码器，所述M元编码器被配置为产生每个包括k位的M-1个不同符号。 M等于2k，k是正整数。 发射机还包括码发生器，其被配置为基于由M元编码器产生的符号并且基于第一和第二Gold码多项式来产生扩频码字序列。 发射机基于扩频码字序列发送无线电信号。 接收机被配置为接收无线电信号。 接收机包括：第一移位寄存器，被配置为接收基于所接收的无线电信号生成的输入信号;以及第二移位寄存器，其被配置为接收和循环移位与用于编码符号的码字序列相同的本地生成的码字序列。

公开(公告)号：US06430212B1

公开(公告)日：2002-08-06

申请号：US09522393

申请日：2000-03-09

申请人： Jalal Alisobhani ,  Donald K. Leimer ,  Richard Kai-Tuen Woo ,  Mark Philip Kaplan

发明人： Jalal Alisobhani ,  Donald K. Leimer ,  Richard Kai-Tuen Woo ,  Mark Philip Kaplan

IPC分类号： H04B1707

CPC分类号： H04L27/22 ,  H04B1/707 ,  H04L27/2017 ,  H04L2027/0028 ,  H04L2027/0055

摘要： A communication device includes a transmitter and receiver. The transmitter includes an M-ary encoder configured to generate an M−1 number of distinctive symbols each comprising k bits. M is equal to 2k and k is a positive integer. The transmitter also includes a code generator configured to produce spread spectrum codeword sequences based on the symbols generated by the M-ary encoder and based on a first and a second Gold code polynomials. The transmitter sends a radio signal based on the spread spectrum codeword sequences. The receiver is configured to receive the radio signal. The receiver includes a first shift register configured to receive an input signal generated based on the received radio signal and a second shift register configured to receive and circularly shift a locally generated codeword sequence that is identical to the codeword sequence used to encode the symbols. The receiver also includes an accumulator coupled to the first and second shift registers and configured to multiply and accumulate stored values in the first and second shift registers each time the second shift register is circularly shifted and a selecting device coupled to the accumulator and configured to identify one symbol from the plurality of symbols based on outputs from the accumulator. A method corresponding to the device is also provided.

摘要翻译： 通信设备包括发射机和接收机。 所述发射机包括M元编码器，所述M元编码器被配置为产生每个包括k位的M-1个不同符号。 M等于2k，k是正整数。 发射机还包括码发生器，其被配置为基于由M元编码器产生的符号并且基于第一和第二Gold码多项式来产生扩频码字序列。 发射机基于扩频码字序列发送无线电信号。 接收机被配置为接收无线电信号。 接收机包括：第一移位寄存器，被配置为接收基于所接收的无线电信号而生成的输入信号;以及第二移位寄存器，其被配置为接收和循环移位与用于编码符号的码字序列相同的本地生成的码字序列。 接收机还包括耦合到第一移位寄存器和第二移位寄存器的累加器，并且被配置为每当第二移位寄存器被循环移位时对第一移位寄存器和第二移位寄存器中存储的值进行乘法和累积，以及耦合到累加器并被配置为识别 基于来自累加器的输出的多个符号中的一个符号。 还提供了与该装置对应的方法。

公开(公告)号：US5808582A

公开(公告)日：1998-09-15

申请号：US795608

申请日：1997-02-05

申请人： Richard Kai-Tuen Woo

发明人： Richard Kai-Tuen Woo

IPC分类号： G01S1/00 ,  G01S19/22 ,  G01S19/29 ,  H04B1/10 ,  H04L7/00 ,  G01S5/02

CPC分类号： G01S19/22 ,  G01S19/29

摘要： A global positioning system receiver includes an inbound signal terminal to receive an inbound global positioning system signal having an inbound PRN code from a global positing system signal source. A local PRN code generator is configured to generate a local PRN code. A discriminator is coupled to the inbound signal terminal and to the local PRN code generator and configured to compare the inbound signal and the local PRN code and to generate a discriminator signal containing a positive portion and a negative portion. A processor is coupled to the discriminator and configured to receive the discriminator signal to process the discriminator signal to determine a bit code and to determine a distance from the global positing system signal source based on said bit code. In one embodiment, the discriminator includes an acquisition mode configured to acquire the inbound PRN code wherein the discriminator has a first gate width and a tracking mode configured to track the PRN code wherein the discriminator has a second gate width less than the first gate width. Advantages of the invention include improved multipath signal rejection.

摘要翻译： 全球定位系统接收机包括入站信号终端，用于从全局定位系统信号源接收具有入站PRN码的入站全局定位系统信号。 本地PRN代码生成器被配置为生成本地PRN代码。 鉴别器耦合到入站信号终端和本地PRN码发生器，并被配置为比较入站信号和本地PRN码，并产生包含正部分和负部分的鉴别信号。 处理器耦合到鉴别器，并被配置为接收鉴别器信号以处理鉴别器信号以确定位码，并根据所述位码确定与全局定位系统信号源的距离。 在一个实施例中，鉴别器包括获取模式，其被配置为获取入站PRN码，其中鉴别器具有第一栅极宽度，跟踪模式被配置为跟踪PRN码，其中鉴别器具有小于第一栅极宽度的第二栅极宽度。 本发明的优点包括改进的多径信号抑制。