公开(公告)号：US06332008B1

公开(公告)日：2001-12-18

申请号：US09170018

申请日：1998-10-13

申请人： Thomas R Giallorenzi ,  Samuel C Kingston ,  Robert W Steagall ,  Patrick J Smith ,  Steven T Barham

发明人： Thomas R Giallorenzi ,  Samuel C Kingston ,  Robert W Steagall ,  Patrick J Smith ,  Steven T Barham

IPC分类号： H04L700

CPC分类号： H04B1/7085

摘要： Users or subscribers of a spread spectrum synchronous communications system provide signals to the central station or base unit of that system, and receive signals therefrom. Proper synchronization among those users (and their signals) is needed to ensure proper operation of the system. To ensure proper synchronization among those users, the signal produced by each user is checked for presence and amount of any offset error. This is accomplished by using three despreaders for the signal for each user. For one such user, each such despreader for that user receives the spreading code for that user. However, the spreading code as received by any one such despreader is time-delayed with respect to the spreading code as received by the other two despreaders. Each such despreader receives the spreading code with a different amount of delay imposed on that spreading code. The outputs of the three despreaders are digitally combined (e.g. compared), or compared, to produce the offset estimate for that user. To reduce noise effects, the offset estimate is averaged over a predetermined time duration; alternatively, such averaging can be performed on the outputs of the despreaders, or at some intermediate processing step. The offset estimate is sent to the user, to be used to correct synchronization of that user. Offset estimates that are too small to be useful are squelched and are not so sent to the user, to reduce channel usage and thereby save bandwidth.

摘要翻译： 扩频同步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。 需要这些用户（及其信号）之间的正确同步，以确保系统的正常运行。 为了确保这些用户之间的正确同步，检查每个用户产生的信号是否存在和任何偏移量错误的量。 这是通过使用三个解扩器为每个用户的信号来实现的。 对于一个这样的用户，用于该用户的每个这样的解扩器接收该用户的扩展码。 然而，由任何一个这样的去扩展器接收的扩展码相对于由其他两个解扩器接收到的扩展码是时间延迟的。 每个这样的解扩器以不同的延迟量来接收扩展码。 三个解扩器的输出被数字组合（例如比较）或比较，以产生该用户的偏移估计。 为了减少噪声影响，偏移估计在预定的持续时间内被平均化; 或者，可以对解扩器的输出执行这样的平均，或者在一些中间处理步骤。 偏移估计被发送给用户，用于纠正该用户的同步。 偏移估计太小而无法用于压缩，不会发送给用户，以减少通道使用率，从而节省带宽。

公开(公告)号：US5867525A

公开(公告)日：1999-02-02

申请号：US872398

申请日：1997-06-10

申请人： Thomas R Giallorenzi ,  Samuel C Kingston ,  Robert W Steagall ,  Patrick J Smith ,  Steven T Barham

发明人： Thomas R Giallorenzi ,  Samuel C Kingston ,  Robert W Steagall ,  Patrick J Smith ,  Steven T Barham

IPC分类号： H04B1/10 ,  H04B1/7085 ,  H04L7/00 ,  H04B15/00 ,  H04K1/00 ,  H04L27/30

CPC分类号： H04B1/7085

摘要： Users or subscribers of a spread spectrum synchronous communications system provide signals to the central station or base unit of that system, and receive signals therefrom. Proper synchronization among those users (and their signals) is needed to ensure proper operation of the system. To ensure proper synchronization among those users, the signal produced by each user is checked for presence and amount of any offset error. This is accomplished by using three despreaders for the signal for each user. For one such user, each such despreader for that user receives the spreading code for that user. However, the spreading code as received by any one such despreader is time-delayed with respect to the spreading code as received by the other two despreaders. Each such despreader receives the spreading code with a different amount of delay imposed on that spreading code. The outputs of the three despreaders are digitally combined (e.g. compared), or compared, to produce the offset estimate for that user. To reduce noise effects, the offset estimate is averaged over a predetermined time duration; alternatively, such averaging can be performed on the outputs of the despreaders, or at some intermediate processing step. The offset estimate is sent to the user, to be used to correct synchronization of that user. Offset estimates that are too small to be useful are squelched and are not so sent to the user, to reduce channel usage and thereby save bandwidth.

摘要翻译： 扩频同步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。 需要这些用户（及其信号）之间的正确同步，以确保系统的正常运行。 为了确保这些用户之间的正确同步，检查每个用户产生的信号是否存在和任何偏移量错误的量。 这是通过使用三个解扩器为每个用户的信号来实现的。 对于一个这样的用户，用于该用户的每个这样的解扩器接收该用户的扩展码。 然而，由任何一个这样的去扩展器接收的扩展码相对于由其他两个解扩器接收到的扩展码是时间延迟的。 每个这样的解扩器以不同的延迟量来接收扩展码。 三个解扩器的输出被数字组合（例如比较）或比较，以产生该用户的偏移估计。 为了减少噪声影响，偏移估计在预定的持续时间内被平均化; 或者，可以对解扩器的输出执行这样的平均，或者在一些中间处理步骤。 偏移估计被发送给用户，用于纠正该用户的同步。 偏移估计太小而无法用于压缩，不会发送给用户，以减少通道使用率，从而节省带宽。

公开(公告)号：US5903551A

公开(公告)日：1999-05-11

申请号：US5938

申请日：1998-01-12

申请人： Samuel C Kingston ,  Thomas R. Giallorenzi ,  Randal R Sylvester ,  David W Matolak ,  Patrick J Smith

发明人： Samuel C Kingston ,  Thomas R. Giallorenzi ,  Randal R Sylvester ,  David W Matolak ,  Patrick J Smith

IPC分类号： H04B1/7075 ,  H04B1/7103 ,  H04B7/24 ,  H04B7/26 ,  H04B7/216

CPC分类号： H04B1/70755 ,  H04B1/70753 ,  H04B1/7103 ,  H04B2201/709709

摘要： Disclosed are methods for acquiring a forward channel in a point-to-multipoint CDMA system. One method includes the steps of (a) despreading a received CDMA signal with a first pn code that is known to be present in the received CDMA signal and obtaining a first measure of received signal level; (b) despreading the received CDMA signal with a second pn code that is known not to be present in the received CDMA signal and obtaining a second measure of received signal level; and (c) synchronizing to a desired channel using a difference between the first and second signal levels. In this method the first step of despreading despreads a continuously transmitted side-channel, and the step of synchronizing synchronizes to the side-channel. Also, the step of obtaining a first measure of received signal level obtains a correlation peak, and the step of obtaining a second measure of received signal level obtains a correlation null. Preferably, the steps of despreading and obtaining are accomplished iteratively over a range of n first pn code phase states and over a range of n second pn code phase states.

摘要翻译： 公开了用于在点对多点CDMA系统中获取前向信道的方法。 一种方法包括以下步骤：（a）使用已知存在于所接收的CDMA信号中的第一pn码解扩接收的CDMA信号，并获得接收信号电平的第一测量值; （b）用已知不存在于所接收的CDMA信号中的第二pn码解扩接收的CDMA信号，并获得接收信号电平的第二测量值; 以及（c）使用第一和第二信号电平之间的差异来同步到期望的信道。 在该方法中，解扩的第一步骤对连续发送的侧信道进行解扩，并且同步步骤与侧信道同步。 此外，获得接收信号电平的第一测量的步骤获得相关峰值，并且获得接收信号电平的第二测量的步骤获得相关无效。 优选地，解扩和获得的步骤在n个第一pn码相位状态的范围内以及在n个第二pn码相位状态的范围上迭代地完成。