公开(公告)号：US20070076788A1

公开(公告)日：2007-04-05

申请号：US11244305

申请日：2005-10-04

申请人： Zhike Jia ,  Chi-Shin Wang

发明人： Zhike Jia ,  Chi-Shin Wang

IPC分类号： H04B1/00

CPC分类号： G01S19/30 ,  G01S19/24

摘要： Methods to achieve data bit synchronization from weak navigational satellite signals are based on a maximum likelihood criterion. The bit synchronization technique may be implemented by calculating a normalized dot product of two consecutive one-millisecond correlation values. Similar normalized dot products are calculated at intervals separated by one bit duration, and these dot products are summed and compared with pre-computed thresholds to declare bit edge detection. In another implementation, the normalized dot product of adjacent correlation values is replaced by a coherent integration powers of adjacent correlation values.

摘要翻译： 从弱导航卫星信号实现数据位同步的方法是基于最大似然准则。 比特同步技术可以通过计算两个连续的1毫秒相关值的归一化点积来实现。 以间隔一位持续时间的间隔计算相似的归一化点积，并将这些点积相加并与预先计算的阈值进行比较以声明位边缘检测。 在另一实现中，相邻相关值的归一化积积由相邻相关值的相干积分能量代替。

公开(公告)号：US20070046536A1

公开(公告)日：2007-03-01

申请号：US11218298

申请日：2005-08-31

申请人： Zhike Jia ,  Chi-Shin Wang

发明人： Zhike Jia ,  Chi-Shin Wang

IPC分类号： G01S5/14 ,  H04B1/707

CPC分类号： G01S19/24 ,  G01S19/246 ,  G01S19/29 ,  G01S19/35 ,  H04B1/7085

摘要： A method and device to track navigational satellite signals, are claimed. In this invention, a combination of down-sampling and frequency domain transformation are used to track the navigational satellite signals under dynamic environment. A Fast Fourier Transform (FFT) with long coherent integration has been employed to determine the varying frequency components with high resolution. By representing a number of correlation values with their average value, it is possible to represent a long sequence of input values by a smaller number of values and a relatively short length FFT can reveal the low frequency components that are present in the signal during tracking operation. A large reduction in the computational load may be achieved using this down-sampling method without compromising on the frequency resolution.

摘要翻译： 声称用于跟踪导航卫星信号的方法和装置。 在本发明中，使用下采样和频域变换的组合来跟踪在动态环境下的导航卫星信号。 已经采用具有长相干积分的快速傅里叶变换（FFT）来确定具有高分辨率的变化频率分量。 通过用其平均值表示多个相关值，可以通过较小数量的值表示输入值的长序列，并且相对较短的长度可以显示在跟踪操作期间在信号中存在的低频分量 。 使用这种下采样方法可以在不影响频率分辨率的情况下实现计算负荷的大幅度减小。

公开(公告)号：US20100328145A1

公开(公告)日：2010-12-30

申请号：US11612426

申请日：2006-12-18

申请人： Chi-Shin Wang ,  Yue-Meng Chen ,  Zhike Jia ,  EnYuan Tu

发明人： Chi-Shin Wang ,  Yue-Meng Chen ,  Zhike Jia ,  EnYuan Tu

IPC分类号： G01S19/41

CPC分类号： G01S19/13 ,  G01S19/24

摘要： The present invention provides systems and methods for downloading navigation data to a satellite receiver under weak signal conditions. In an embodiment, the receiver uses a tracking algorithm to estimate the Doppler frequency and rate of change of the Doppler frequency to compensate the phases of the I/Q samples from the received signal to reduce the effect of the Doppler frequency. In an embodiment, differential detection based data bit decoding is provided. In another embodiment, phase compensation based data bit decoding is provided, in which the phase of samples are rotated to compensate for phase error. In an embodiment, a multiple frame strategy is provided to increase signal-to-noise ratio (SNR) and improve sensitivity, in which similar placed samples in consecutive frames are coherently summed over the consecutive frames. In an embodiment, the samples are weighted to reduce the impact of noise in the multiple frame strategy.

摘要翻译： 本发明提供了在弱信号条件下将导航数据下载到卫星接收机的系统和方法。 在一个实施例中，接收机使用跟踪算法来估计多普勒频率的多普勒频率和变化率，以便从接收信号中补偿I / Q采样的相位，以减少多普勒频率的影响。 在一个实施例中，提供了基于差分检测的数据比特解码。 在另一个实施例中，提供了基于相位补偿的数据比特解码，其中样本的相位被旋转以补偿相位误差。 在一个实施例中，提供多帧策略以增加信噪比（SNR）并提高灵敏度，其中连续帧中的类似放置样本在连续帧上相干相加。 在一个实施例中，加权样本以减少多帧策略中噪声的影响。

公开(公告)号：US07847726B2

公开(公告)日：2010-12-07

申请号：US11615431

申请日：2006-12-22

申请人： Zhike Jia ,  Shridhara A. Kurethaya ,  Chi-Shin Wang

发明人： Zhike Jia ,  Shridhara A. Kurethaya ,  Chi-Shin Wang

IPC分类号： G01S1/00

CPC分类号： G01S19/34 ,  G01S19/24

摘要： The present invention provides systems and methods for navigational signal tracking in low power mode to conserve the power of handheld navigation receivers. In an embodiment, the receiver cycles between sleep and wakeup states. During the sleep state, most of the components of the receiver are powered off to conserve power, and during the wakeup state, the receiver tracks navigational signals. In an embodiment, the duty cycle of the sleep/wakeup states depends on the receiver dynamic state, e.g., whether the receiver is accelerating. In another embodiment, during the wakeup state, the receiver selects a tracking mode based on the signal strength. Under weak signal conditions, a tracking mode using a long integration to track the satellite signal is disclosed. In one embodiment, a tracking mode tracks the navigation signal by performing data aided integration using known or predicted data bits, such as the TLM and HOW words.

摘要翻译： 本发明提供了用于低功率模式的导航信号跟踪的系统和方法，以节省手持式导航接收机的功率。 在一个实施例中，接收器在睡眠和唤醒状态之间循环。 在睡眠状态期间，接收机的大多数组件被关闭以节省功率，并且在唤醒状态期间，接收器跟踪导航信号。 在一个实施例中，睡眠/唤醒状态的占空比取决于接收机的动态状态，例如接收机是否正在加速。 在另一个实施例中，在唤醒状态期间，接收机基于信号强度来选择跟踪模式。 在弱信号条件下，公开了使用长积分跟踪卫星信号的跟踪模式。 在一个实施例中，跟踪模式通过使用已知或预测的数据位（诸如TLM和HOW字）执行数据辅助积分来跟踪导航信号。

公开(公告)号：US07456782B2

公开(公告)日：2008-11-25

申请号：US11322654

申请日：2005-12-29

申请人： Chi-Shin Wang ,  Lianxue Xiong ,  Zhike Jia ,  Lei Dong ,  Jingbin Liu

发明人： Chi-Shin Wang ,  Lianxue Xiong ,  Zhike Jia ,  Lei Dong ,  Jingbin Liu

IPC分类号： G01S5/14

CPC分类号： G01S19/235 ,  G01S19/23 ,  G01S19/26 ,  G01S19/34

摘要： The present invention provides GPS receivers with clock calibration for fast reacquisition of GPS signals after waking up from a sleep state or coming out of signal blockage. In a preferred embodiment, a GPS receiver comprises a local clock based on an oscillator, e.g., crystal oscillator. The GPS receiver calculates a clock calibration value based on a computed oscillator count for the period during which the GPS receiver is in the sleep state or the signal is blocked. This clock calibration value is used to calibrate the local clock after the GPS receiver wakes up or comes out of signal blockage for fast reacquisition of GPS signals.

摘要翻译： 本发明提供具有时钟校准的GPS接收机，用于在从休眠状态唤醒或从信号阻塞出来之后快速重新捕获GPS信号。 在优选实施例中，GPS接收机包括基于例如晶体振荡器的振荡器的本地时钟。 GPS接收机基于GPS接收机处于睡眠状态或信号被阻塞的周期的计算振荡器计数来计算时钟校准值。 该时钟校准值用于在GPS接收器唤醒或者信号阻塞之后校准本地时钟，以快速重新获取GPS信号。

公开(公告)号：US20080180321A1

公开(公告)日：2008-07-31

申请号：US11694786

申请日：2007-03-30

申请人： Chi-Shin Wang ,  Zhike Jia ,  Yue-Meng Chen ,  Jian Cheng ,  EnYuan Tu

发明人： Chi-Shin Wang ,  Zhike Jia ,  Yue-Meng Chen ,  Jian Cheng ,  EnYuan Tu

IPC分类号： G01S5/14 ,  G01S1/04

CPC分类号： H04B1/7075 ,  G01S19/235 ,  G01S19/29

摘要： Provided herein are systems and methods for achieving long coherent integration in a navigational receiver to improve the sensitivity of the receiver and enable the receiver to acquire, reacquire and track signals under very weak signal conditions. In an embodiment, phase compensation is computed based on estimated Doppler frequency, rate of change of the Doppler frequency with time, and second order rate of change of the Doppler frequency. The Doppler frequency may be computed from an orbital model or ephemeris. This phase compensation is used to compensate samples of the input signal for changes in the phase due to the Doppler frequency. Frequency components of the phase-compensated samples are then computed using a frequency analysis such as a Fast Fourier Transform (FFT). The maximum frequency component is taken as an error frequency and used to compensate the samples of the input signal for residual frequency error.

摘要翻译： 本文提供了用于在导航接收机中实现长相干集成以提高接收机的灵敏度并使接收机能够在非常弱的信号条件下获取，重新获取和跟踪信号的系统和方法。 在一个实施例中，基于估计的多普勒频率，多普勒频率随时间的变化率和多普勒频率的二阶变化率来计算相位补偿。 多普勒频率可以从轨道模型或星历计算。 该相位补偿用于补偿由于多普勒频率引起的相位变化的输入信号的样本。 然后使用诸如快速傅立叶变换（FFT）的频率分析来计算相位补偿样本的频率分量。 将最大频率分量作为误差频率，用于补偿输入信号的样本以获得残余频率误差。

公开(公告)号：US08094758B2

公开(公告)日：2012-01-10

申请号：US11612426

申请日：2006-12-18

申请人： Chi-Shin Wang ,  Yue-Meng Chen ,  Zhike Jia ,  EnYuan Tu

发明人： Chi-Shin Wang ,  Yue-Meng Chen ,  Zhike Jia ,  EnYuan Tu

IPC分类号： H04B1/00

CPC分类号： G01S19/13 ,  G01S19/24

摘要： The present invention provides systems and methods for downloading navigation data to a satellite receiver under weak signal conditions. In an embodiment, the receiver uses a tracking algorithm to estimate the Doppler frequency and rate of change of the Doppler frequency to compensate the phases of the I/Q samples from the received signal to reduce the effect of the Doppler frequency. In an embodiment, differential detection based data bit decoding is provided. In another embodiment, phase compensation based data bit decoding is provided, in which the phase of samples are rotated to compensate for phase error. In an embodiment, a multiple frame strategy is provided to increase signal-to-noise ratio (SNR) and improve sensitivity, in which similar placed samples in consecutive frames are coherently summed over the consecutive frames. In an embodiment, the samples are weighted to reduce the impact of noise in the multiple frame strategy.

摘要翻译： 本发明提供了在弱信号条件下将导航数据下载到卫星接收机的系统和方法。 在一个实施例中，接收机使用跟踪算法来估计多普勒频率的多普勒频率和变化率，以便从接收信号补偿I / Q采样的相位，以减少多普勒频率的影响。 在一个实施例中，提供了基于差分检测的数据比特解码。 在另一个实施例中，提供了基于相位补偿的数据比特解码，其中样本的相位被旋转以补偿相位误差。 在一个实施例中，提供多帧策略以增加信噪比（SNR）并提高灵敏度，其中连续帧中的类似放置样本在连续帧上相干相加。 在一个实施例中，加权样本以减少多帧策略中噪声的影响。

公开(公告)号：US07778311B2

公开(公告)日：2010-08-17

申请号：US11244305

申请日：2005-10-04

申请人： Zhike Jia ,  Chi-Shin Wang

发明人： Zhike Jia ,  Chi-Shin Wang

IPC分类号： H04B1/00

CPC分类号： G01S19/30 ,  G01S19/24

摘要： Methods to achieve data bit synchronization from weak navigational satellite signals are based on a maximum likelihood criterion. The bit synchronization technique may be implemented by calculating a normalized dot product of two consecutive one-millisecond correlation values. Similar normalized dot products are calculated at intervals separated by one bit duration, and these dot products are summed and compared with pre-computed thresholds to declare bit edge detection. In another implementation, the normalized dot product of adjacent correlation values is replaced by a coherent integration powers of adjacent correlation values.

摘要翻译： 从弱导航卫星信号实现数据位同步的方法是基于最大似然准则。 比特同步技术可以通过计算两个连续的1毫秒相关值的归一化点积来实现。 以间隔一位持续时间的间隔计算相似的归一化点积，并将这些点积相加并与预先计算的阈值进行比较以声明位边缘检测。 在另一实现中，相邻相关值的归一化积积由相邻相关值的相干积分能量代替。

公开(公告)号：US20090168851A1

公开(公告)日：2009-07-02

申请号：US11428800

申请日：2006-07-05

申请人： Chi-Shin Wang ,  Jian Cheng ,  Zhike Jia ,  Shridhara A. Kudrethaya

发明人： Chi-Shin Wang ,  Jian Cheng ,  Zhike Jia ,  Shridhara A. Kudrethaya

IPC分类号： H04B1/707

CPC分类号： H04B1/7075 ,  H04B1/7085 ,  H04B1/7095 ,  H04B2201/70715

摘要： The present invention provides systems and methods for faster acquisition and more stable tracking of spread spectrum signals with lower computational load requirements. Instead of the present day practice of using only the Prompt correlator, the systems and methods of the invention use the sum of the powers of all the correlators of a channel to determine the acquisition or tracking of the signal. These systems and methods improve the signal acquisition speed resulting in a reduced Time-To-First-Fix (TTFF). Further, these systems and methods improve the acquisition and tracking sensitivity of the receiver.

摘要翻译： 本发明提供了具有较低计算负荷要求的用于更快速采集和更稳定地跟踪扩频信号的系统和方法。 代替现在仅使用Prompt相关器的做法，本发明的系统和方法使用信道的所有相关器的功率之和来确定信号的采集或跟踪。 这些系统和方法提高了信号采集速度，从而缩短了首次固定时间（TTFF）。 此外，这些系统和方法提高了接收机的采集和跟踪灵敏度。

公开(公告)号：US20080143594A1

公开(公告)日：2008-06-19

申请号：US11612421

申请日：2006-12-18

申请人： Chi-Shin Wang ,  Yue-Meng Chen ,  Zhike Jia ,  Enyuan Tu

发明人： Chi-Shin Wang ,  Yue-Meng Chen ,  Zhike Jia ,  Enyuan Tu

IPC分类号： H04B7/185

CPC分类号： H04B7/18589 ,  G01S19/243 ,  G01S19/246 ,  G01S19/27

摘要： The present invention provides systems and methods for downloading navigation data to a satellite receiver under weak signal conditions. In an embodiment, the receiver uses a tracking algorithm to estimate the Doppler frequency and rate of change of the Doppler frequency to compensate the phases of the I/Q samples from the received signal to reduce the effect of the Doppler frequency. In an embodiment, differential detection based data bit decoding is provided. In another embodiment, phase compensation based data bit decoding is provided, in which the phase of samples are rotated to compensate for phase error. In an embodiment, a multiple frame strategy is provided to increase signal-to-noise ratio (SNR) and improve sensitivity, in which similar placed samples in consecutive frames are coherently summed over the consecutive frames. In an embodiment, the samples are weighted to reduce the impact of noise in the multiple frame strategy.

摘要翻译： 本发明提供了在弱信号条件下将导航数据下载到卫星接收机的系统和方法。 在一个实施例中，接收机使用跟踪算法来估计多普勒频率的多普勒频率和变化率，以便从接收信号中补偿I / Q采样的相位，以减少多普勒频率的影响。 在一个实施例中，提供了基于差分检测的数据比特解码。 在另一个实施例中，提供了基于相位补偿的数据比特解码，其中样本的相位被旋转以补偿相位误差。 在一个实施例中，提供多帧策略以增加信噪比（SNR）并提高灵敏度，其中连续帧中的类似放置样本在连续帧上相干相加。 在一个实施例中，加权样本以减少多帧策略中噪声的影响。