公开(公告)号：US5630208A

公开(公告)日：1997-05-13

申请号：US277150

申请日：1994-07-19

申请人： Per Enge ,  Dominic Farmer ,  John F. Schipper

发明人： Per Enge ,  Dominic Farmer ,  John F. Schipper

IPC分类号： H04B7/005 ,  H04B1/10

CPC分类号： H04B1/711 ,  H04B7/005

摘要： Method and apparatus for using a plurality of correlators to improve an estimate of direct signal arrival time by identifying features of a correlation function at and adjacent to the correlation peak. In a first embodiment, the errors in location of the center point of a correlation function R(.tau.), formed by the incoming composite signal and a stored copy of the expected signal, are assumed to be strongly correlated for narrow sample spacing and wide sample spacing of the correlation function. In a second embodiment, multipath signal strengths and phases are estimated, using multiple sampling of the correlation function R(.tau.). This approach assumes that path delays of the direct signal and of the multipath signals can be determined separately. Path delays can be determined by any of at least three approaches: (1) identification of slope transition points in the correlation function; (2) Cepstrum processing of the received signal, using Fourier transform analysis; and (3) use of a grid of time points on the correlation function domain, and identification of time values, associated with certain solution parameters of the least mean squares analysis that have the largest absolute values, as times of arrival of the direct and multipath signals. Separate identification of multipath time delays reduces the least mean squares analysis to a linear problem. A modified signal is constructed, with the multipath signal(s) approximately removed from the incoming composite signal. This modified signal allows a better estimate of the arrival time of the direct signal.

摘要翻译： 用于使用多个相关器来通过识别和相邻相关峰值的相关函数的特征来改善直接信号到达时间的估计的方法和装置。 在第一实施例中，假定由输入复合信号形成的相关函数R（τ）的中心点的位置误差和预期信号的存储副本对于窄采样间隔和宽采样是强相关的 相关函数的间距。 在第二实施例中，使用相关函数R（τ）的多个采样来估计多径信号强度和相位。 该方法假设可以分别确定直接信号和多径信号的路径延迟。 路径延迟可以通过至少三种方法中的任何一种来确定：（1）识别相关函数中的斜率跃迁点; （2）倒频谱处理的接收信号，采用傅里叶变换分析; 和（3）在相关函数域上使用时间网格，以及与具有最大绝对值的最小均方分析的某些解的参数相关联的时间值的识别作为直接和多径的到达时间 信号。 多路径时间延迟的分离识别将线性问题的最小均方分析降低。 构造修改的信号，其中多路径信号从输入的复合信号中大致去除。 该修改的信号允许更好地估计直接信号的到达时间。

公开(公告)号：US5465413A

公开(公告)日：1995-11-07

申请号：US27004

申请日：1993-03-05

申请人： Per Enge ,  Dominic Farmer ,  Brian Westfall

发明人： Per Enge ,  Dominic Farmer ,  Brian Westfall

IPC分类号： H04B1/12

CPC分类号： H04B1/123

摘要： Method and apparatus for reducing or cancelling impulse noise from a signal containing noise. The desired noise-free signal is assumed to have a representative frequency .omega..sub.3, but may have a range of frequencies adjacent to this frequency, and is assumed to have substantially zero amplitude for all frequencies .omega. .omega..sub.2, where .omega..sub.1

公开(公告)号：US4800391A

公开(公告)日：1989-01-24

申请号：US116461

申请日：1987-11-03

申请人： Per Enge

发明人： Per Enge

IPC分类号： G01S1/24 ,  G01S5/00 ,  H04B14/02 ,  H03K7/04

CPC分类号： H04B14/026 ,  G01S1/24 ,  G01S5/0009

摘要： In a Loran-C message communication system a method of obviating errors in navigation locking caused by sampling reception at the conventional symmetrical pulse modulation time intervals in advance of and in delay from the normal transmission interval, through rendering the pulse modulation assymetrical to a degree that compensates for different cycle amplitudes at sampling points above and below the desired sixth zero crossing used for navigation position determination.

摘要翻译： 在Loran-C消息通信系统中，提供一种在通常的对称脉冲调制时间间隔的采样接收引起的导航锁定中的误差的方法，其通过将脉冲调制方式与正常发送间隔进行比较， 在用于导航位置确定的期望的第六个零交叉点之上和之下的采样点补偿不同的周期振幅。

公开(公告)号：US06930639B2

公开(公告)日：2005-08-16

申请号：US10390331

申请日：2003-03-14

申请人： Frank N. Bauregger ,  Per Enge ,  Todd Walter ,  Dennis Akos

发明人： Frank N. Bauregger ,  Per Enge ,  Todd Walter ,  Dennis Akos

IPC分类号： H01Q1/38 ,  H01Q3/24 ,  H01Q9/04 ,  H01Q21/28 ,  H01Q1/50 ,  H01Q21/00

CPC分类号： H01Q9/0442 ,  H01Q1/38 ,  H01Q3/247 ,  H01Q9/0414 ,  H01Q9/0428 ,  H01Q21/28

摘要： Method and apparatus for reducing radio frequency interference (RFI) using a dual-element patch antenna [10]. The antenna possesses two antenna elements [13, 14] having distinct radiation patterns. Either element may be independently selected using a DC bias voltage. Diodes [20] connected to the elements serve to disable one element when the other is selected. In one selected mode, a nominal radiation pattern provides a broad, hemispherical shaped sensitivity that is designed for acquiring and tracking all navigation satellites above the horizon. This nominal radiation pattern, however, is susceptible to interference that is present near or below the horizon. The second selectable radiation pattern of the dual-element antenna has comparatively higher gain toward zenith, and lower gain at and below the horizon to mitigate interference. This combination of features is packaged in a single antenna unit that can be a direct replacement for existing antennas. The dual-element antenna unit has a low vertical profile and is suitable for mounting on high-speed moving vehicles.

摘要翻译： 使用双元件贴片天线降低射频干扰（RFI）的方法和装置[10]。 天线具有两个具有不同辐射图案的天线元件[13,14]。 可以使用DC偏置电压独立地选择任一元件。 连接到元件的二极管[20]用于在选择另一个元件时禁用一个元件。 在一种选择的模式中，标称辐射图形提供广泛的半球形灵敏度，其设计用于获取和跟踪地平线以上的所有导航卫星。 然而，这种标称辐射模式易于存在于地平线附近或之下的干扰。 双元件天线的第二种可选择的辐射图形具有相对较高的天顶增益，并且在水平线上和下方的增益较低以减轻干涉。 这种特征的组合被封装在单个天线单元中，其可以是现有天线的直接替代。 双元件天线单元具有低垂直轮廓，适合安装在高速移动车辆上。

公开(公告)号：US6031882A

公开(公告)日：2000-02-29

申请号：US851873

申请日：1997-05-06

申请人： Per Enge ,  Dominic Farmer ,  John F. Schipper

发明人： Per Enge ,  Dominic Farmer ,  John F. Schipper

IPC分类号： H04B7/005 ,  H04L27/06

CPC分类号： H04B1/711 ,  H04B7/005

摘要： Method and apparatus for using a plurality of correlators to improve the estimate of direct signal arrival time by identifying detailed features of a correlation function at and adjacent to the correlation peak. The errors in location of the center point of a correlation function R(.tau.), formed by the received signal and a stored copy of the expected signal, are assumed to be strongly correlated for narrow sample spacing and wide sample spacing of the correlation function. Alternatively, the multipath signal strengths and phases are estimated by a least mean squares analysis, using multiple sampling of a correlation function of an expected signal and an arriving composite signal that includes the direct signal and one or more multipath signals. Times of arrival or path delays of the direct signal and the multipath signals are determined separately. Path delays can be determined by at least three approaches: (1) identification of slope transition points in the correlation function R(.tau.); (2) Cepstrum processing of the received signal, using Fourier transform and inverse transform analysis; and (3) use of a grid of time shift points for the correlation function, and identification of time shift values, associated with certain solution parameters for a least mean squares analysis that have the largest absolute values, as times of arrival of the direct and multipath signals. Separate identification of path delays reduces the least mean squares analysis to a solvable linear problem. A modified received signal is constructed, with multipath signal(s) approximately removed.

摘要翻译： 一种用于使用多个相关器来通过识别和相邻相关峰值的相关函数的详细特征来改善直接信号到达时间的估计的方法和装置。 假设由接收信号形成的相关函数R（τ）的中心点的位置误差和期望信号的存储副本对于相关函数的窄采样间隔和宽采样间隔而言是强相关的。 或者，使用预期信号的相关函数和包括直接信号和一个或多个多径信号的到达复合信号的多次采样，通过最小均方分析来估计多径信号强度和相位。 分别确定直达信号和多径信号的到达时间或路径延迟。 路径延迟可以通过至少三种方法来确定：（1）识别相关函数R（τ）中的斜率跃迁点; （2）使用傅里叶变换和逆变换分析对接收信号进行倒谱处理; 和（3）使用相关函数的时间移位点网格，以及与具有最大绝对值的最小均方分析的某些解决方案参数相关联的时移值的识别作为直接和 多径信号 路径延迟的单独识别将最小均方分析降低到可解的线性问题。 构造修改的接收信号，其中多径信号被近似去除。