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公开(公告)号：US5654991A
公开(公告)日：1997-08-05
申请号：US509588
申请日：1995-07-31
CPC分类号： H04B1/70755 , H04L7/0054 , H04B2201/70707
摘要： In a direct sequence spread spectrum receiver, an apparatus for obtaining and adjusting bit synchronization. In one aspect, the bit synchronization is adjusted by selectively inverting a clocking circuit to delay sampling by one-half a clock cycle and to combine the inversion with a skipping of one cycle to advance the sampling by one-half cycle. In another aspect of the invention, the synchronization circuit avoids overflow of accumulating components by downshifting both the partial sums and the input data when needed.
摘要翻译： 在直接序列扩频接收机中，用于获取和调整比特同步的装置。 在一个方面，通过选择性地反相时钟电路来调整比特同步，以将采样延迟半个时钟周期，并将反演与一个周期的跳过组合，以将采样推进半个周期。 在本发明的另一方面，同步电路通过在需要时降低部分和数据和输入数据来避免积累分量的溢出。
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公开(公告)号：USRE40231E1
公开(公告)日：2008-04-08
申请号：US10005483
申请日：2001-11-09
CPC分类号： H04J13/0048 , H04B1/707 , H04J13/12 , H04L27/18
摘要： A spread spectrum radio transceiver includes a high data rate baseband processor and a radio circuit connected thereto. The baseband processor preferably includes a modulator for spread spectrum phase shift keying (PSK) modulating information for transmission via the radio circuit. The modulator may include at least one modified Walsh code function encoder for encoding information according to a modified Walsh code for substantially reducing an average DC signal component to thereby enhance overall system performance when AC-coupling the received signal through at least one analog-to-digital converter to the demodulator. The demodulator is for spread spectrum PSK demodulating information received from the radio circuit. The modulator and demodulator are each preferably operable in one of a bi-phase PSK (BPSK) mode at a first data rate and a quadrature PSK (QPSK) mode at a second data rate. These formats may also be switched on-the-fly in the demodulator. Method aspects are also disclosed.
摘要翻译： 扩频无线电收发机包括高数据速率基带处理器和与其连接的无线电电路。 基带处理器优选地包括用于扩展频谱相移键控（PSK）调制信号以用于经由无线电电路传输的调制器。 调制器可以包括至少一个修改的沃尔什码功能编码器，用于根据修改的沃尔什码对信息进行编码，用于基本上减小平均DC信号分量，从而当通过至少一个模数转换器将AC接收到的信号进行AC耦合时， 数字转换器到解调器。 解调器用于从无线电电路接收的扩频PSK解调信息。 调制器和解调器各自优选以第二数据速率以第一数据速率和正交PSK（QPSK）模式的双相PSK（BPSK）模式之一工作。 这些格式也可以在解调器中进行即时切换。 还公开了方法方面。
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公开(公告)号：US5732105A
公开(公告)日：1998-03-24
申请号：US509586
申请日：1995-07-31
摘要： A method of estimating signal quality in a radio demodulator receiving an input stream of symbols includes the steps of sampling a phase-only portion of each of the symbols in the input stream, determining a phase error for each of the samples of the phase-only portions, and calculating a signal quality estimate from a plurality of the sample phase errors. The signal quality estimate may be an average magnitude of a predetermined number of sample phase errors. The input stream may be symbols in the preamble, or symbols in the data signal that follows.
摘要翻译： 在接收输入符号流的无线电解调器中估计信号质量的方法包括以下步骤：对输入流中每个符号的相位部分进行采样，确定每相相位样本的相位误差 部分，并且从多个样本相位误差计算信号质量估计。 信号质量估计可以是预定数量的采样相位误差的平均幅度。 输入流可以是前导码中的符号，或者随后的数据信号中的符号。
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4.发明授权Short burst acquisition circuit and method for direct sequence spread spectrum links 失效短脉冲串采集电路和直接序列扩频链路的方法
公开(公告)号：US5883921A
公开(公告)日：1999-03-16
申请号：US509587
申请日：1995-07-31
CPC分类号： H04B1/70751 , H04B1/70775 , H04B1/7087 , H04B1/709 , H04B7/0811 , H04B1/71
摘要： A digital data radio receiver and method evaluates a data signal preamble received on an antenna to determine whether the antenna should receive the data signal following the preamble. The receiver determines frequency offsets from a desired frequency for each symbol in a block of symbols in the preamble, determines the variance of the frequency offsets, determines the average magnitude of the symbols in the block of symbols, where the determination of average magnitude may be performed in parallel with the determination of variance of the frequency offsets, and evaluates the variance and the average magnitude for the block of symbols to determine whether the preamble is actually noise and to assess reception quality at the antenna. In a two antenna diversity receiver system, these steps may be performed first on a block of symbols received at one antenna and then performed on the next block of symbols received at another antenna. This provides two evaluations that may be compared to select the antenna with the best reception.
摘要翻译： 数字数据无线电接收机和方法评估在天线上接收的数据信号前导码，以确定天线是否应该接收在前导码之后的数据信号。 接收机从前导码中的符号块中的每个符号确定来自期望频率的频率偏移，确定频率偏移的方差，确定符号块中的符号的平均幅度，其中平均幅度的确定可以是 与频率偏移的方差的确定并行执行，并且评估符号块的方差和平均幅度以确定前同步码是否实际上是噪声并且评估天线的接收质量。 在两天线分集接收机系统中，这些步骤可以首先在一个天线接收的符号块上执行，然后在另一个天线接收的下一个符号块上执行。 这提供了可以与选择具有最佳接收的天线进行比较的两个评估。
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