Symbol synchronizer for software defined communications system signal combiner
    1.
    发明授权
    Symbol synchronizer for software defined communications system signal combiner 失效
    用于软件定义的通信系统信号组合器的符号同步器

    公开(公告)号:US06836507B1

    公开(公告)日:2004-12-28

    申请号:US09639496

    申请日:2000-08-14

    IPC分类号: H04B1707

    摘要: A symbol synchronizer (100) is provided for a software-defined communications system (10). The symbol synchronizer (100), when integrated into either a pre- or post-detection diversity signal combiner (108, 208), enables highly accurate signal synchronization with minimal added system complexity. The symbol synchronizer (100) includes a single complex sliding window matched filter (102) for filtering an input digital signal with a match filtering function based on predetermined signal transfer function characteristics to average out receiver noise from the signal. A signal delay bank (84) includes a plurality of delay blocks each for delaying the digital signal filtered by the single matched filter for a predetermined number of samples. A complex correlator (88) correlates the digital signal filtered by the single complex sliding window matched filter (102) and delayed by the complex correlator (88) with a correlator reference signal, and selects an index of a path having a peak correlator value. As a result of such a configuration, the symbol synchronizer (100) is capable of determining symbol boundaries of channel signals in a multi-channel communications system to enable system signal measurement statistics and demodulated to be more accurately generated.

    摘要翻译: 为软件定义的通信系统(10)提供符号同步器(100)。 符号同步器(100)当被集成到检测前或检测后分集信号组合器(108,208)中时,能够以最小的附加系统复杂度实现高度准确的信号同步。 符号同步器(100)包括单个复合滑动窗口匹配滤波器(102),用于基于预定的信号传递函数特性对具有匹配滤波功能的输入数字信号进行滤波,以平均信号中的接收机噪声。 信号延迟组(84)包括多个延迟块,每个延迟块用于将由单个匹配滤波器滤波的数字信号延迟预定数量的样本。 复相关器(88)使由单个复合滑动窗口匹配滤波器(102)滤波并由复相关器(88)延迟的数字信号与相关器参考信号相关,并且选择具有峰值相关器值的路径的索引。 作为这样的配置的结果,符号同步器(100)能够确定多通道通信系统中的信道信号的符号边界,以使系统信号测量统计信号和解调更准确地产生。

    Multi-stage rake combining methods and apparatus
    2.
    发明授权
    Multi-stage rake combining methods and apparatus 有权
    多级耙组合方法与装置

    公开(公告)号:US06801565B1

    公开(公告)日:2004-10-05

    申请号:US09344898

    申请日:1999-06-25

    IPC分类号: H04B1707

    摘要: Information encoded in a spread spectrum signal transmitted in a communications medium is recovered. A composite signal including a spread spectrum signal is received from the communications medium, and correlated with a spreading sequence to generate time-offset correlations. Respective first and second groups of the correlations are combined, e.g., according to estimated channel coefficients, to produce respective first and second combined values. The first and second combined values are then combined in a manner that compensates for correlated impairment in the composite signal to generate an estimate information in the transmitted spread spectrum signal, e.g., using weighting factors generated from an estimated composite channel response and an estimated impairment correlation, or adaptively generated weighting factors. Related apparatus are also described.

    摘要翻译: 在通信介质中发送的扩频信号中编码的信息被恢复。 从通信介质接收包括扩展频谱信号的复合信号,并与扩展序列相关以产生时间偏移相关。 各个相关的第一和第二组例如根据估计的信道系数被组合,以产生相应的第一和第二组合值。 然后,以补偿复合信号中的相关损害的方式组合第一和第二组合值,以在发射的扩频信号中产生估计信息,例如,使用从估计的复合信道响应和估计的损耗相关性产生的加权因子 ,或自适应产生的加权因子。 还描述了相关装置。

    Method and apparatus for performing reverse rate matching in a CDMA system
    3.
    发明授权
    Method and apparatus for performing reverse rate matching in a CDMA system 有权
    用于在CDMA系统中执行反向速率匹配的方法和装置

    公开(公告)号:US06798826B1

    公开(公告)日:2004-09-28

    申请号:US09707349

    申请日:2000-11-06

    IPC分类号: H04B1707

    摘要: Techniques for processing symbols received for a (transport) channel in a (W-CDMA) communication system. According to the W-CDMA standard, the coded bits of a transport channel are first rate-matched, then first de-interleaved, and then segmented to form X radio frames, where X is the transmission time interval (TTI) of the transport channel. The radio frames can be processed in various manners. In one aspect, the rate-matching and first interleaving can be applied to the coded bits of the transport channel X times to generate a radio frame with each application. In accordance with a method, the correspondence between the coded bit xm and the rate-matched bits yn, and between the rate-matched bits yn and the interleaved bits zk, can be computed based on direct or iterative computations. In another aspects, the first de-interleaving and inverse rate-matching can be applied onto each rad it is received, without having to wait for the remaining radio frames in the TTI to be received. The correspondences between the received symbols zk′, de-interleaved symbols yn′ and de-rate-matched symbols xm′ can be computed. Reduced buffering requirement and reduced processing delays may be achieved based on the above.

    摘要翻译: 用于处理(W-CDMA)通信系统中为(传输)信道接收的符号的技术。 根据W-CDMA标准,传输信道的编码比特首先进行速率匹配,然后首先解交织,然后分段形成X个无线帧,其中X是传输信道的传输时间间隔(TTI) 。 无线电帧可以以各种方式进行处理。 在一个方面,速率匹配和第一交织可以被应用于传输信道X的编码比特,以产生每个应用的无线帧。 根据一种方法,可以基于直接或迭代计算来计算编码比特xm和速率匹配比特yn之间以及速率匹配比特yn和交织比特zk之间的对应关系。 在另一方面,可以将第一解交织和反比特率匹配应用于其接收的每个弧度上,而不必等待接收到TTI中的剩余无线电帧。 可以计算接收符号zk',解交织符号yn'和解速率匹配符号xm'之间的对应关系。 基于上述可以实现减少缓冲要求和减少的处理延迟。

    Spread spectrum signal demodulator
    4.
    发明授权
    Spread spectrum signal demodulator 失效
    扩频信号解调器

    公开(公告)号:US06763059B2

    公开(公告)日:2004-07-13

    申请号:US09730762

    申请日:2000-12-07

    IPC分类号: H04B1707

    CPC分类号: H04B1/71075

    摘要: This invention provides a spread spectrum signal demodulator in which a noise component included in respective demodulation symbols is reduced and an effect of interference removal is further improved. Symbol decorrelating means detect correlations between spread codes allocated to spread spectrum signals to be removed and a receiving signal. A symbol deciding means 121 synthesizes one or the plurality of one symbol correlation values b1 to bk in common phase, namely, diversity-synthesizes them so as to decide a symbol. As the symbol decision, hard decision or soft decision can be used. Correlation modification means input the one symbol correlation values b1 to bk output from the symbol decorrelating means and the symbol decided result output from the symbol deciding means 121 thereinto, and modify the symbol correlation values b1 to bk. The modified symbol correlation values d1 to dk are transmitted into interference replicating means so as to be spectrum-spread by corresponding spread codes.

    摘要翻译: 本发明提供一种扩频信号解调器,其中包括在各个解调符号中的噪声分量被减少,并且进一步提高了干扰去除的效果。 符号去相关装置检测分配给要去除的扩频信号的扩展码与接收信号之间的相关性。 符号决定单元121将共同相位中的一个或多个符号相关值b1〜bk进行合成,即对它们进行分集合成,从而决定符号。 作为符号决定,可以使用硬判决或软判决。 相关修正意味着输入从符号解相关装置输出的一个符号相关值b1至bk和从符号确定装置121输出的符号确定结果,并修改符号相关值b1至bk。 经修改的符号相关值d1至dk被发送到干扰复制装置,以便通过相应的扩展码进行频谱扩展。

    Low signal to noise ratio acquisition and link characterization techniques for VSAT spread spectrum modems
    5.
    发明授权
    Low signal to noise ratio acquisition and link characterization techniques for VSAT spread spectrum modems 有权
    用于VSAT扩频调制解调器的低信噪比采集和链路表征技术

    公开(公告)号:US06763058B1

    公开(公告)日:2004-07-13

    申请号:US09604461

    申请日:2000-06-27

    申请人: James R. Morris

    发明人: James R. Morris

    IPC分类号: H04B1707

    CPC分类号: H04B7/216

    摘要: A direct sequence spread spectrum (DS-SS) communications modem for low signal to noise ratio applications and secure communications systems (10). The modulator (22) implements a quadrature-phase shift keying (QPSK) modulation scheme in which a pseudonoise code is supplied to one channel and a pseudonoise code is combined with data to define the other channel. The demodulator (34) receives the modulated signal and utilizes a signal acquisition processor (92) in order to detect the pseudonoise code applied to the first channel. Upon detection and acquisition of the first pseudonoise code, the second pseudonoise code may be determined in order to demodulate the second channel to yield the modulated data. The signal acquisition processor (92) provides numerous parametric measurements to enable fine demodulator tuning and robust acquisition of the pseudonoise spreading codes on the I and Q channels.

    摘要翻译: 用于低信噪比应用和安全通信系统的直接序列扩频(DS-SS)通信调制解调器(10)。 调制器(22)执行正交相移键控(QPSK)调制方案,其中将伪噪声码提供给一个通道,并将伪噪声码与数据组合以定义另一通道。 解调器(34)接收调制信号并利用信号采集处理器(92)来检测施加到第一信道的伪噪声码。 在检测和获取第一伪噪声码时,可以确定第二伪噪声码以便解调第二信道以产生调制数据。 信号采集处理器(92)提供大量的参数测量,以便在I和Q通道上实现精细解调器调谐和鲁棒地获取伪噪声扩展码。

    Efficient multicarrier filter
    7.
    发明授权
    Efficient multicarrier filter 失效
    高效多载波滤波器

    公开(公告)号:US06748011B2

    公开(公告)日:2004-06-08

    申请号:US09756843

    申请日:2001-01-09

    IPC分类号: H04B1707

    摘要: A multi-carrier filter for a wireless communications system employing a multi-carrier signal. The multi-carrier filter includes a first mechanism for receiving the multi-carrier signal and extracting carrier signal components of the multi-carrier signal in response thereto. A second mechanism filters the carrier signal components and outputs a demodulated and filtered multi-bandwidth signal in response thereto. In the specific embodiment, the first mechanism includes a rotator. The multi-carrier signal is a 3× bandwidth multi-carrier signal having three carrier components. The three carrier components include a center carrier, a left carrier, and a right carrier. The center carrier, the left carrier, and the right carrier are separated by approximately 1.25 MHz. The rotator is a lookup table rotator that includes a mechanism for selectively rotating the multi-carrier-signal clockwise or counter clockwise and outputting the left carrier or the right carrier, respectively, in response thereto.

    摘要翻译: 一种用于采用多载波信号的无线通信系统的多载波滤波器。 多载波滤波器包括用于接收多载波信号并且响应于此提取多载波信号的载波信号分量的第一机制。 第二机制对载波信号分量进行滤波并响应于此输出解调和滤波的多带宽信号。 在具体实施例中,第一机构包括转子。 多载波信号是具有三个载波分量的3×带宽多载波信号。 三个载体部件包括中心载体,左载体和右载体。 中心载波,左载波和右载波分离约1.25 MHz。 旋转器是一种查阅表旋转器,其包括用于分别顺序地或逆时针地选择性地旋转多载波信号的机构,并响应于此分别输出左载波或右载波。

    Near-optimal low-complexity decoding of space-time codes for fixed wireless applications

    公开(公告)号:US06741635B2

    公开(公告)日:2004-05-25

    申请号:US10234407

    申请日:2002-09-03

    申请人: Titus Lo Vahid Tarokh

    发明人: Titus Lo Vahid Tarokh

    IPC分类号: H04B1707

    摘要: An improved multi-antenna receiver is realized for detecting signals transmitted by a multi-antenna transmitter by summing signals received at the plurality of receiver antennas after multiplying each by a respective constant. The summed signal is applied to a maximum likelihood detector. The respective constants, &lgr;j, where j is an index designating a particular receiver antenna, are determined by evaluating the largest eigenvector of the matrix A, where &Lgr; is a vector containing the values &lgr;j, and A is a matrix containing elements &agr;ij, which is the transfer function between the ith transmitter antenna to the jth receiver antenna. The &agr;ij terms are determined in the receiver in conventional ways.

    Transmission power control method of measuring Eb/N0 after weighted signals are combined
    9.
    发明授权
    Transmission power control method of measuring Eb/N0 after weighted signals are combined 有权
    加权信号后测量Eb / N0的发射功率控制方法相结合

    公开(公告)号:US06724808B1

    公开(公告)日:2004-04-20

    申请号:US09607145

    申请日:2000-06-29

    申请人: Manabu Ohshima

    发明人: Manabu Ohshima

    IPC分类号: H04B1707

    摘要: A transmission power control method of measuring an Eb/N0 after weighted signals are combined is disclosed. A plurality of rake receivers detect respective received signals for respective paths, delay demodulated data which are the detection result based on a set delay time, and then combine and output the demodulated data. A multipath searcher acquires reception delay information which is information on a delay time among the respective paths contained in the received signals. A rake receiver control unit sets the delay times for the rake receivers based on the reception delay information acquired by the multipath searcher. A plurality of first weighting units weight the demodulated data output from the respective rake receivers. A first combining unit combines the signals weighted by the first weighting units into one signal. An Eb/N0 measuring unit measures an Eb/N0 of the demodulated data combined by the first combining unit.

    摘要翻译: 公开了一种组合加权信号后测量Eb / N0的发送功率控制方法。 多个前置接收机检测相应路径的各个接收信号,并根据设定的延迟时间对作为检测结果的解调数据进行延迟,然后合并并输出解调数据。 多径搜索器获取接收延迟信息,该接收延迟信息是包含在接收信号中的相应路径中的关于延迟时间的信息。 耙机接收机控制单元基于由多路径搜索器获取的接收延迟信息来设置耙机接收机的延迟时间。 多个第一加权单元对从各个前置接收器输出的解调数据加权。 第一组合单元将由第一加权单元加权的信号组合成一个信号。 Eb / N0测量单元测量由第一组合单元组合的解调数据的Eb / N0。

    Correlator for realizing low current consumption
    10.
    发明授权
    Correlator for realizing low current consumption 失效
    相关器实现低电流消耗

    公开(公告)号:US06690716B1

    公开(公告)日:2004-02-10

    申请号:US09518949

    申请日:2000-03-06

    申请人: Soichi Tsumura

    发明人: Soichi Tsumura

    IPC分类号: H04B1707

    摘要: A correlator can stop correlation computation on the basis of the value of a despreading code, and decreases the operation ratio of a section operated in accordance with a despreading code pattern to ½ that of a conventional scheme (when spreading is performed by BPSK). This correlator reduces the current consumption to about ½ that of the conventional scheme (when spreading is performed by BPSK) in a case of a sufficiently high spreading ratio by using a common total adder regardless of the despreading code pattern, thereby realizing lower current consumption than the conventional correlator without decreasing the operation speed.

    摘要翻译: 相关器可以基于解扩码的值来停止相关计算,并且将根据解扩码模式操作的部分的操作比降低到传统方案的一半(当通过BPSK进行扩频时)的操作比。 该相关器将电流消耗降低到常规方案的1/2(通过BPSK进行扩展时),通过使用公共总加法器,在扩展率足够高的情况下,不管解扩码模式如何,从而实现较低的电流消耗 传统的相关器,而不降低运行速度。