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1. 发明授权

US06370397B1 Search window delay tracking in code division multiple access communication systems 失效
标题翻译：在码分多址通信系统中搜索窗口延迟跟踪
公开(公告)号：US06370397B1
公开(公告)日：2002-04-09
申请号：US09070778
申请日：1998-05-01
申请人： Branislav M. Popović , Frank Georg , Matthlas Schulist , Göran Klang
发明人： Branislav M. Popović , Frank Georg , Matthlas Schulist , Göran Klang
IPC分类号： H04B138
CPC分类号： H04B1/7085 , G01S5/0215 , H04B1/7113 , H04B1/7117
摘要： The present invention provides a search window delay tracking procedure for use in a multipath search processor of a CDMA radio receiver. A channel impulse responses is estimated for a received signal containing plural paths, each path having a corresponding path delay. A search window defines a delay profile that contains the plural paths of the received signal. A mean or average delay is calculated for the estimated channel impulse response (CIR), and an error is determined between the mean CIR delay and a desired delay position corresponding to the center of the CIR search window. An adjustment is made to reduce that error so that the center of the search window and the mean CIR delay are aligned. The error may be processed either linearly (in one embodiment) or non-linearly (in another embodiment) to minimize the error and to reduce an influence of noise. A non-linear filtering process includes calculating a delay spread from the mean CIR delay calculated for successive processing cycles of a window delay tracking procedure corresponding to each new input. A difference is determined between the successive delay spreads. Adjustment signal is set equal to the error signal if the difference is less than or equal to a threshold. Alternatively, the adjustment signal is set to zero if the difference is greater than the threshold. Consequently, if the delay spread in the current iteration is significantly different from the delay spread in the previous iteration, the new error sample calculated in the current iteration is considered unreliable, and no adjustment is made.
摘要翻译：本发明提供了一种在CDMA无线电接收机的多路径搜索处理器中使用的搜索窗延迟跟踪程序。对于包含多个路径的接收信号估计信道脉冲响应，每个路径具有对应的路径延迟。搜索窗口定义包含接收信号的多个路径的延迟分布。对于估计的信道脉冲响应（CIR）计算平均或平均延迟，并且在平均CIR延迟和对应于CIR搜索窗口的中心的期望延迟位置之间确定误差。进行调整以减少该误差，使得搜索窗口的中心和平均CIR延迟对齐。该错误可以线性地（在一个实施例中）或非线性（在另一个实施例中）处理以最小化误差并减少噪声的影响。非线性滤波处理包括从对应于每个新输入的窗延迟跟踪程序的连续处理周期计算的平均CIR延迟来计算延迟扩展。在连续的延迟传播之间确定差异。如果差值小于或等于阈值，则将调整信号设置为等于误差信号。或者，如果差值大于阈值，则将调整信号设置为零。因此，如果当前迭代中的延迟扩展与前一次迭代中的延迟扩展明显不同，则在当前迭代中计算出的新的误差样本被认为是不可靠的，不进行调整。

2. 发明授权

US06363106B1 Method and apparatus for despreading OQPSK spread signals 失效
标题翻译：用于解扩OQPSK扩展信号的方法和装置
公开(公告)号：US06363106B1
公开(公告)日：2002-03-26
申请号：US09039371
申请日：1998-03-16
申请人： Branislav M. Popović , Göran Klang
发明人： Branislav M. Popović , Göran Klang
IPC分类号： H04L2730
CPC分类号： H04B1/707 , H04L27/2331
摘要： Incoming signals in a receiver for Direct Sequence Code Division Multiple Access systems are despread using Offset-QPSK spreading as the transmitting spreading format combined with arbitrary data modulation formats, such as BPSK and QPSK. The receiver has a pseudonoise (PN) generator for generating a unique PN sequence signal. The PN sequence signal is divided into a real and an imaginary component. The complex input signal is divided into inphase and quadrature components. The inphase and the quadrature components of the input signal are downsampled to provide either two complex samples per chip period or one complex sample per chip period. In the latter case, the downsampling instants are delayed by a quarter of a chip period. Each downsampled complex signal is correlated with the corresponding segment of the complex PN sequence signal of the receiver. In the case where two samples per chip are provided after downsampling, the correlation values obtained for odd and even complex samples of the downsampled input signal are summed.
摘要翻译：用于直接序列码分多址系统的接收机中的接收信号使用偏移QPSK扩展作为与任意数据调制格式（诸如BPSK和QPSK）组合的发射扩展格式进行解扩。接收机具有用于产生唯一PN序列信号的伪噪声（PN）发生器。 PN序列信号被分成实部和虚部。复合输入信号被分为同相和正交分量。输入信号的同相和正交分量被下采样以在每个码片周期提供两个复杂样本或每个码片周期提供一个复杂样本。在后一种情况下，下采样时刻延迟了芯片周期的四分之一。每个下采样的复信号与接收机的复数PN序列信号的相应段相关。在下采样之后提供每个芯片两个样本的情况下，对下采样输入信号的奇数和偶数复样本获得的相关值相加。

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