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公开(公告)号：US4979170A
公开(公告)日：1990-12-18
申请号：US145176
申请日：1988-01-19
IPC分类号： G02B6/293 , G02B6/34 , G02B6/42 , H01S3/08 , H01S5/14 , H01S5/40 , H04B1/7136 , H04B7/212 , H04B10/155 , H04L5/16
CPC分类号： H04B1/7136 , G02B6/12007 , G02B6/2931 , G02B6/29328 , G02B6/29383 , G02B6/4206 , G02B6/4246 , G02B6/4249 , G02B6/425 , H01S3/08009 , H01S5/141 , H04B10/506 , H04B7/212 , H04L5/16 , G02B6/29334 , H01S5/4025 , H01S5/4062 , H01S5/4087
摘要： A message communication system employing one or more centralized communication stations transferring messages through Earth orbit repeater satellites to or from mobile terminals with at least one central communication station having a first transceiver for transmitting a first communication signal to one or more mobile terminals and at least one mobile terminal having a second transceiver for receiving the first communication signal and demodulating it, and for transmitting at a predetermined duty cycle of the second transceiver, a second communication signal to at least one of the central communication stations. The preferred duty cycle over which the second communication signal is transmitted is about fifty percent of the second transceiver duty cycle. The communication system uses Time Division Multiplexed (TDM) communication signals using a number of channels as designated address channels with the remainder being used for data transfer. Information transmitted on the address channels is used by terminals to determine both the presence of a message and its corresponding data transmission or reception channel. In addition the terminals use the reception of the first communication signal to adjust return link transmission frequency to compensate for transmission path errors. The alternating duty cycle allows mobile terminals to use a single set of local oscillators for both transmission and reception modes of operation. To decrease interference with other systems the present system employs a power dispersal modulation function to achieve the footprint of a video signal for high transfer rate digital communication signals.
摘要翻译： 一种消息通信系统，其采用一个或多个集中式通信站，其中至少一个中央通信站通过地球轨道中继卫星向移动终端传送消息，所述至少一个中央通信站具有用于将第一通信信号发送到一个或多个移动终端的第一收发器和至少一个 移动终端具有用于接收第一通信信号并对其进行解调的第二收发器，并且用于以第二收发器的预定占空比发送第二通信信号到至少一个中央通信站。 发送第二通信信号的优选占空比大约是第二收发器占空比的百分之五十。 通信系统使用时分复用（TDM）通信信号，使用多个信道作为指定地址信道，其余部分用于数据传输。 在地址信道上发送的信息被终端用于确定消息的存在及其对应的数据发送或接收信道。 此外，终端使用第一通信信号的接收来调整返回链路传输频率以补偿传输路径错误。 交替占空比允许移动终端在传输和接收操作模式下使用单组本地振荡器。 为了减少与其他系统的干扰，本系统采用功率分散调制功能来实现高传输速率数字通信信号的视频信号的覆盖区。
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公开(公告)号：US5017926A
公开(公告)日：1991-05-21
申请号：US446979
申请日：1989-12-05
CPC分类号： G01S19/00 , G01S13/46 , G01S13/876 , G01S19/38 , G01S5/14 , G01S2013/466
摘要： A method and system for determining the position of an object using a fixed station and a plurality of earth orbit satellites whose positions are known. Separate periodic signals are transmitted from the fixed station via first and second satellites to the object whose postion is to be determined. The phase offset in periodic characteristics of the periodic signals as received from the first and second satellites is measured at the object. The phase offset corresponds to a relative time difference in propagation of the signals traveling two different paths to the object. The object transmits via the first satellite a return signal indicative of the measured relative time difference. This return signal is activated some time in the future according to the object local time, which is slaved to receipt of the periodic signal sent through the first satellite. This future time is the start of the particular time period as decided by the fixed station's schedule. At the fixed station, an instantaneous round trip delay, determined by the time offset of the current transmission clock time relative to the receive clock time of reception of the return signal, along with the measured relative time difference sent back on the return signal, is used to calculate the distances between the first and second satellites to the object. From these distances the position of the object is calculated.
摘要翻译： 一种用于使用固定站和位置已知的多个地球轨道卫星来确定物体的位置的方法和系统。 分离的周期信号从固定站经由第一和第二卫星发送到要确定位置的对象。 在物体处测量从第一和第二卫星接收的周期性信号的周期特性中的相位偏移。 相位偏移对应于传播到对象的两个不同路径的信号的传播的相对时间差。 物体经由第一卫星发送指示所测量的相对时间差的返回信号。 该返回信号在将来根据对象本地时间被激活一段时间，该对象本地时间被接收通过第一卫星发送的周期信号。 这个未来时间是由固定电台的时间表决定的特定时间段的开始。 在固定站，由当前传输时钟时间相对于接收返回信号的接收时钟时间的时间偏移确定的瞬时往返延迟以及在返回信号上发回的测量的相对时间差是 用于计算第一和第二卫星与物体之间的距离。 从这些距离计算物体的位置。
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13.发明授权
公开(公告)号：US4901307A
公开(公告)日：1990-02-13
申请号：US921261
申请日：1986-10-17
CPC分类号： H04B7/2041 , H04B7/216 , H04B2201/70701
摘要： A multiple access, spread spectrum communication system and method for providing high capacity communications to, from, or between a plurality of system users, using code-division-spread-spectrum communication signals. The communication system uses means for providing marginal isolation between user communication signals. The marginal isolation is provided by generating simultaneous multiple steerable beams; using an omni-directional antenna with polarization enhancement; using power control devices to adjust the output power for user generated communication signals either in response to their input activity level, or in accordance with a minimum allowable power for maintaining a communication link. The communication system can also employ a means for transmitting a predetermined pilot chip sequence contiguous with the code-division-spread-spectrum communication signals.In further embodiments the communication system employs a plurality of user terminals linked to each other or to other services through one or more terrestrial or satellite repeaters. Multiple satellite repeaters are operable in a new communication mode to obtain further gains in signal isolation.
摘要翻译： 一种使用码分扩频通信信号向多个系统用户提供高容量通信的多址，扩频通信系统和方法。 通信系统使用用于在用户通信信号之间提供边缘隔离的装置。 边缘隔离通过同时产生多个可操纵梁来提供; 使用具有极化增强的全向天线; 使用功率控制装置来响应于其输入活动水平或根据用于维持通信链路的最小允许功率来调整用户生成的通信信号的输出功率。 通信系统还可以采用用于发送与码分扩展频谱通信信号相邻的预定导频码片序列的装置。 在另外的实施例中，通信系统采用通过一个或多个地面或卫星中继器彼此链接或与其他服务相连的多个用户终端。 多个卫星中继器可以在新的通信模式下操作，以获得信号隔离的进一步增益。
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公开(公告)号：US5126748A
公开(公告)日：1992-06-30
申请号：US702900
申请日：1991-05-20
CPC分类号： G01S13/876 , G01S13/46 , G01S5/0009 , G01S5/12 , G01S2013/466
摘要： A system and method for determining the position of an airborne object, using a fixed station and a pair of earth orbit satellites whose positions are known. Separate periodic signals are transmitted from the fixed station via the first and second satellites to the object whose position is to be determined. The phase offset in periodic characteristics of the periodic signals as received from the first and second satellites is measured at the object. The phase offset corresponds to a realtive time difference in propagation of the signals traveling two different paths to the object. The object transmits via the first satellite a return signal indicative of the measured relative time difference. This return signal is activated some time in the future according to the object local time, which is slaved to receipt of the periodic signal sent through the first satellite. This future time is the start of the particular time period as decided by the fixed station's schedule. At the fixed station, an instantaneous round trip delay, determined by the time offset of the current transmission clock time relative to the receive clock time of reception of the return signal, along with the measured relative time difference sent back on the return signal, is used to calculate the distances between the first and second satellites to the object. From these distances, along with the combined altitude of the object with the distance from the surface of the earth to the center of the earth, the position of the object is calculated.
摘要翻译： 一种用于确定机载物体的位置的系统和方法，其使用已知位置的固定站和一对地球轨道卫星。 分离的周期信号从固定站经由第一和第二卫星发送到要确定其位置的对象。 在物体处测量从第一和第二卫星接收的周期性信号的周期特性中的相位偏移。 相位偏移对应于将两个不同路径传播到物体的信号传播的实时时差。 物体经由第一卫星发送指示所测量的相对时间差的返回信号。 该返回信号在将来根据对象本地时间被激活一段时间，该对象本地时间被接收通过第一卫星发送的周期信号。 这个未来时间是由固定电台的时间表决定的特定时间段的开始。 在固定站，由当前传输时钟时间相对于接收返回信号的接收时钟时间的时间偏移确定的瞬时往返延迟以及在返回信号上发回的测量的相对时间差是 用于计算第一和第二卫星与物体之间的距离。 从这些距离，以及与地球表面到地球中心距离的物体的组合高度，计算物体的位置。
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