GPS receiver
    1.
    发明授权
    GPS receiver 失效
    GPS接收器

    公开(公告)号:US5222245A

    公开(公告)日:1993-06-22

    申请号:US668822

    申请日:1991-03-13

    IPC分类号: G01S1/00 G01S19/27

    CPC分类号: G01S19/24 G01S19/34

    摘要: A GPS receiver includes a power supplying status detector for deriving a power-on or power-off signal by detecting a power supplying status of the GPS receiver, a clock for measuring time, a memory controller for controlling a nonvolatile memory upon receiving the power-off signal to store a time measured by the clock when the power is turned off or a time when the last ephemeris data is obtained and the last ephemeris data, and a position calculating circuitry for calculating the position of the user station upon receiving the power-on signal. A time duration is calculated from the time measured by the clock and the time stored in the nonvolatile memory. If it is determined that the measured time duration is shorter than a predetermined period of time, the positioning is performed based on the respective ephemeris data stored in the nonvolatile memory, whereas if it is determined that the measured time duration is no less than the predetermined period of time, the positioning is performed based on ephemeris data newly collected from the respective GPS satellites.

    Apparatus and method for positioning of a GPS receiver
    2.
    发明授权
    Apparatus and method for positioning of a GPS receiver 失效
    GPS接收机定位装置及方法

    公开(公告)号:US5248981A

    公开(公告)日:1993-09-28

    申请号:US657784

    申请日:1991-02-20

    IPC分类号: G01S1/00

    CPC分类号: G01S19/14 G01S19/36 G01S19/42

    摘要: A GPS receiver and related method for positioning on the Globe. The GPS receiver receives satellite signals in a sequential manner with a plurality of antennas, whereby any of the plurality of antennas which receives satellite signals from the maximum number of GPS satellites is selected by an antenna switching unit under the control of a control unit, a combination of GPS satellites having the smallest PDOP value or the signal strength in due order is selected by the control unit from among all of GPS satellites in contact with respective antennas when each of the antennas fails to receive satellite signals transmitted by the predetermined minimum number of GPS satellites. The related positioning method is for use with a motor vehicle-mounted GPS receiver having a plurality of receiving channels, wherein each receiving channel independently receives satellite signals from the GPS satellites in contact, a required number of GPS satellites which are currently considered to be the most suitable for positioning in view of PDOP value are selected from among all of GPS satellites in contact through each receiving channel, and thereby a GPS satellite other than the selected ones may be substituted for the obstructed GPS satellite for carrying out the positioning by making use of navigation data of the newly selected GPS satellite without any intermission.

    System for identifying a responding station for a radio communications
system
    3.
    发明授权
    System for identifying a responding station for a radio communications system 失效
    用于识别无线电通信系统的响应站的系统

    公开(公告)号:US4628537A

    公开(公告)日:1986-12-09

    申请号:US543056

    申请日:1983-10-18

    IPC分类号: H04W12/06 H04B7/00

    CPC分类号: H04W88/022

    摘要: A communications system for identifying a responding station called by a communications system caller station over a call channel and a plurality of speech channels. The system transmits information from the caller station, such as the selected speech channel and the designated responding station through the call channel, and receives information from a responding station on the selected speech channel. The communication between the communications system and the responding station on the selected speech channel is enabled only when information from the responding station is identical to information of the designated responding station transmitted from the communications system.

    摘要翻译: 一种通信系统,用于通过呼叫信道和多个语音信道识别由通信系统呼叫者呼叫的响应站。 该系统通过呼叫信道从诸如所选择的语音信道和指定的响应站之类的主叫站发送信息,并且在所选语音信道上从响应站接收信息。 只有当来自响应站的信息与从通信系统发送的指定的响应站的信息相同时,才能启用通信系统与所选语音信道上的响应站之间的通信。

    Communication apparatus for transmitting and receiving signals on
different frequency bands
    7.
    发明授权
    Communication apparatus for transmitting and receiving signals on different frequency bands 失效
    用于在不同频带上发送和接收信号的通信装置

    公开(公告)号:US4627099A

    公开(公告)日:1986-12-02

    申请号:US686581

    申请日:1984-12-26

    申请人: Masashi Shimakata

    发明人: Masashi Shimakata

    IPC分类号: H04B1/50 H04B1/40

    CPC分类号: H04B1/50

    摘要: A communication apparatus comprises a first oscillator for generating a frequency fp.sub.1 at each channel step; a second oscillator for generating a modulated frequency fp.sub.2 ; a first mixer for creating a transmission frequency which is a sum fp.sub.1 +fp.sub.2 of the frequencies of the first and second oscillators and a difference fp.sub.1 -fp.sub.2 therebetween on high and low band transmissions respectively; a third oscillator for generating a frequency fp.sub.3 which is higher or lower than the frequency fp.sub.2 of the second oscillator by a given frequency .DELTA.f; and a second mixer for creating a sum fp.sub.1 +fp.sub.3 of the frequencies of the first and third oscillators means and a difference fp.sub.1 -fp.sub.3 therebetween on low and high band transmissions respectively.

    摘要翻译: 通信装置包括用于在每个信道步骤产生频率fp1的第一振荡器; 用于产生调制频率fp2的第二振荡器; 第一混合器,用于产生分别在高频和低频传输中的第一和第二振荡器的频率的和fp1 + fp2的传输频率和它们之间的差fp1-fp2; 第三振荡器,用于产生高于或低于所述第二振荡器的频率fp2给定频率DELTA f的频率fp3; 以及第二混频器,用于在低频和高频带传输时分别产生第一和第三振荡器装置的频率的和fp1 + fp3和它们之间的差fp1-fp3。