公开(公告)号：US07209494B1

公开(公告)日：2007-04-24

申请号：US09694870

申请日：2000-10-24

申请人： Dan M Griffin ,  Samuel C. Kingston ,  Delon K. Jones ,  Randal R. Sylvester

发明人： Dan M Griffin ,  Samuel C. Kingston ,  Delon K. Jones ,  Randal R. Sylvester

IPC分类号： H04J3/06

CPC分类号： H04L27/0014 ,  H04B1/7085 ,  H04L2027/0022 ,  H04L2027/003 ,  H04L2027/0077

摘要： A Time Division Duplex (TDD), Code Division Multiple Access (CDMA) communication system includes a plurality of Customer Premises Equipment (CPE) and an Access Point (AP) that communicate through RF links. A CPE contains a receiver baseband subsystem and a transmitter baseband subsystem, and further contains receiver circuitry operable during a receive period for receiving an RF carrier from the AP and for deriving a receiver tracking signal that is indicative of a frequency and phase shift between the received RF carrier and a reference signal. The receiver circuitry further includes a frequency to phase accumulator (FPA) and a digital phase shifter (DPS) for correcting the frequency and phase of a receiver baseband signal by an amount and in a direction indicated by the receiver tracking signal. CPE transmitter circuitry is operable during a next transmission period for operating the FPA and DPS circuitry to correct the frequency of a transmitter baseband signal by an amount indicated by the receiver tracking signal, and in a direction opposite to the direction indicated by the receiver tracking signal.

摘要翻译： 时分双工（TDD），码分多址（CDMA）通信系统包括通过RF链路进行通信的多个客户驻地设备（CPE）和接入点（AP）。 CPE包含接收机基带子系统和发射机基带子系统，并且还包括在接收周期期间可操作以接收来自AP的RF载波的接收机电路，并且用于导出指示接收到的频率和相移之间的接收机跟踪信号 RF载波和参考信号。 接收器电路还包括频率相位累加器（FPA）和数字移相器（DPS），用于将接收器基带信号的频率和相位按接收器跟踪信号指示的量和量来校正。 在下一个传输周期期间，CPE发射机电路可操作，用于操作FPA和DPS电路，以将接收器跟踪信号指示的量校正发射机基带信号的频率，并且在与由接收机跟踪信号指示的方向相反的方向上 。

公开(公告)号：US5917852A

公开(公告)日：1999-06-29

申请号：US873538

申请日：1997-06-11

申请人： Lee A Butterfield ,  Thomas R Giallorenzi ,  L Andrew Gibson, Jr. ,  Dan M Griffin ,  Johnny M Harris ,  Steven B Perkins ,  R William Steagall

发明人： Lee A Butterfield ,  Thomas R Giallorenzi ,  L Andrew Gibson, Jr. ,  Dan M Griffin ,  Johnny M Harris ,  Steven B Perkins ,  R William Steagall

IPC分类号： G09C1/00 ,  H04B1/707 ,  H04L9/20 ,  H04B15/00 ,  H04K1/00 ,  H04L27/30

CPC分类号： H04B1/707

摘要： Users or subscribers of a multi-user communications system, such as a spread spectrum communications system, provide signals to the central station or base unit of that system, and receive signals therefrom. Avoidance of interference among those users' signals is needed to ensure proper operation of the system. To do so, the data of each user is individually scrambled to randomize the data that different users are transmitting, in order to improve tracking performance at a receiver. The data of each user is scrambled independently, in a manner unique to that user in the system, in order to improve tracking performance and detection performance of a receiver. This scrambling makes the multi-user interference zero mean, and makes it possible to integrate out or average out the multi-user interference. The pattern or sequence used for this scrambling, and the pattern or sequence used for spreading here, are preferably identical except in frequency.

摘要翻译： 诸如扩频通信系统的多用户通信系统的用户或用户向该系统的中心站或基站提供信号，并从其接收信号。 需要避免用户信号之间的干扰，以确保系统的正常运行。 为了这样做，每个用户的数据被单独加扰以随机化不同用户正在发送的数据，以便提高接收机的跟踪性能。 为了提高接收机的跟踪性能和检测性能，每个用户的数据以系统中该用户唯一的方式独立地加扰。 这种扰乱使得多用户干扰为零是平均的，并且使得可以整合或平衡多用户干扰。 用于该扰频的模式或序列以及用于在此扩展的模式或序列优选地在频率以外是相同的。

公开(公告)号：US5914961A

公开(公告)日：1999-06-22

申请号：US987810

申请日：1997-12-10

申请人： Johnny M Harris ,  Dan M Griffin

发明人： Johnny M Harris ,  Dan M Griffin

IPC分类号： H04B1/7073 ,  H04B7/26 ,  H04J3/06 ,  H04J13/00

CPC分类号： H04B1/7073

摘要： Disclosed is apparatus including circuitry for providing synchronizing clocks to a transmitter and a receiver of a subscriber unit (SU) that communicates with a radio base unit (RBU) in a synchronous CDMA communication system. The apparatus includes an accumulator for generating a digital signal having a changing magnitude. The accumulator is initialized to a value of a phase command received from the RBU. The apparatus further includes a first circuit having an input coupled to an output of the accumulator for converting a content of the accumulator to a synchronized receiver clock signal, wherein the accumulator content is periodically adjusted to maintain the receiver clock signal in synchronism with a serial bit stream received from the RBU. In accordance with this invention the apparatus further includes a summer circuit having an input coupled to the output of the accumulator for combining the content of the accumulator, representing the commanded receiver side phase difference from RBU timing, with a value of a transmitter timing offset commanded by the RBU. The summer circuit provides a summation signal to a second circuit that converts the summation signal to a synchronized transmitter clock signal. In accordance with this invention problems created by the use of two independent DDSs are avoided by effectively slaving the transmit side DDS to the receive side DDS, thus insuring that the transmit side phase is accurately aligned with the SU phase commanded by the RBU.

摘要翻译： 公开了一种装置，包括用于向同步CDMA通信系统中与无线电基站单元（RBU）通信的用户单元（SU）的发射机和接收机提供同步时钟的电路。 该装置包括用于产生具有变化幅度的数字信号的累加器。 累加器被初始化为从RBU接收的相位命令的值。 所述装置还包括第一电路，其具有耦合到所述累加器的输出的输入端，用于将所述累加器的内容转换成同步的接收机时钟信号，其中周期性地调整所述累加器内容以使接收机时钟信号与串行位同步 从RBU收到的流。 根据本发明，该装置还包括一个加法电路，其具有耦合到累加器的输出的输入端，用于将表示与RBU定时的指令的接收机侧相位差的累加器的内容与指令的发射机定时偏移值相组合 由RBU。 夏季电路向第二电路提供求和信号，该第二电路将求和信号转换成同步的发射机时钟信号。 根据本发明，通过有效地将发送侧DDS从发送侧DDS分离到接收侧DDS来避免使用两个独立的DDS产生的问题，从而确保发送侧相位与由RBU指令的SU相准确对准。