公开(公告)号：US20040258184A1

公开(公告)日：2004-12-23

申请号：US10895879

申请日：2004-07-21

申请人： Broadcom Corporation

发明人： Tian-Min Liu ,  Loke Kun Tan ,  Steven T. Jaffe

IPC分类号： H04L027/06

CPC分类号： H04L27/3827 ,  H04B1/68 ,  H04L25/03057 ,  H04L27/02 ,  H04L27/066 ,  H04L27/2273 ,  H04L27/3427 ,  H04L2025/03382 ,  H04L2025/0342 ,  H04L2025/0349 ,  H04L2025/03503 ,  H04L2027/0032 ,  H04L2027/0042 ,  H04L2027/0057 ,  H04L2027/0067 ,  H04L2027/0087 ,  H04N5/21 ,  H04N5/211 ,  H04N5/44 ,  H04N5/4401 ,  H04N5/46 ,  H04N11/002

摘要： Improved decision feedback equalizer and decision directed timing recovery systems and methods suitable for use in connection with a dual mode QAM/VSB receiver system are disclosed. A trellis decoder operates in conjunction with a decision feedback equalizer circuit on trellis coded 8-VSB modulated signals. The trellis decoder includes a 4-state traceback memory circuit outputting a maximum likelihood decision as well as a number of intermediate decisions based upon the maximum likelihood sequence path. Any number of decisions, along the sequence, may be provided as an input signal to timing recovery system loops, with the particular decision along the sequence chosen on the basis of its delay through the trellis decoder. Variable delay circuitry is coupled to the other input of the timing recovery system loops in order to ensure that both input signals bear the same timestamp. Final decisions are output from the trellis decoder to a DFE in order to enhance the DFE's ability to operate in low SNR environments. A decision sequence estimation error signal is also generated and used to drive the tap updates of both the DFE and an FFE portion of the equalizer.

摘要翻译： 公开了改进的决策反馈均衡器和适用于与双模式QAM / VSB接收机系统相关联的决策定向定时恢复系统和方法。 网格解码器与网格编码的8-VSB调制信号上的判决反馈均衡器电路结合操作。 网格解码器包括基于最大似然序列路径输出最大似然判定以及多个中间决策的4状态追迹存储器电路。 沿序列的任何数量的决定可以作为输入信号提供给定时恢复系统循环，其中沿着根据其通过网格解码器的延迟选择的序列的特定决定。 可变延迟电路耦合到定时恢复系统回路的另一个输入，以确保两个输入信号具有相同的时间戳。 最终决策从网格解码器输出到DF​​E，以提高DFE在低SNR环境下的运行能力。 还产生判决序列估计误差信号并用于驱动均衡器的DFE和FFE部分的抽头更新。

公开(公告)号：US20040258179A1

公开(公告)日：2004-12-23

申请号：US10601152

申请日：2003-06-20

发明人： Jerral A. Long ,  J. Robert Dockemeyer JR. ,  Glenn A. Walker

IPC分类号： H04L027/06

CPC分类号： H04H40/27 ,  H04H20/28 ,  H04H20/30 ,  H04H60/51 ,  H04H60/68 ,  H04H2201/19

摘要： A digital RF receiver and method for providing regional data to a user acquired from a large geographic data broadcast. The RF receiver receives an RF signal containing a stream of broadcast data. The stream of broadcast data includes primary data and more geographically limited regional data. The receiver includes a device for selecting a user specific region, and a decoder for acquiring the regional data. The receiver further includes a data processor for processing the regional data and the selected user specific region to obtain regional data designated for the user specific region, and an output for outputting the regional data pertaining to the selected user specific region.

摘要翻译： 一种用于向从大型地理数据广播获取的用户提供区域数据的数字RF接收器和方法。 RF接收机接收包含广播数据流的RF信号。 广播数据流包括主要数据和更多地理位置有限的区域数据。 接收机包括用于选择用户特定区域的设备和用于获取区域数据的解码器。 接收机还包括用于处理区域数据和所选择的用户特定区域以获得为用户特定区域指定的区域数据的数据处理器，以及用于输出与所选择的用户特定区域有关的区域数据的输出。

公开(公告)号：US20040247053A1

公开(公告)日：2004-12-09

申请号：US10719776

申请日：2003-11-21

申请人： NORTEL NETWORKS LIMITED

发明人： Nidham Ben Rached ,  Thierry Lucidarme

IPC分类号： H04L027/06

CPC分类号： H04W74/004 ,  H04L7/00 ,  H04L7/0012 ,  H04L25/0202 ,  H04W74/0833

摘要： The method seeks detection of a signal burst transmitted on the initiative of a sender on a radio channel listened to by a receiver system. The burst transmitted represents a predetermined digital sequence. Channel parameters representing a statistical behaviour of the radio channel are estimated and a detection magnitude is evaluated on the basis of the estimated channel parameters and of a correlation between a signal received at the receiver system and the predetermined digital sequence. The detection magnitude is compared with an adaptive detection threshold to decide whether the signal burst is detected.

摘要翻译： 该方法寻求在由接收机系统收听的无线电信道上由发送者主动发送的信号突发检测。 发送的突发表示预定的数字序列。 估计表示无线电信道的统计行为的信道参数，并且基于所估计的信道参数以及在接收机系统接收的信号与预定的数字序列之间的相关性来评估检测幅度。 将检测幅度与自适应检测阈值进行比较，以确定是否检测到信号突发。

公开(公告)号：US20040240580A1

公开(公告)日：2004-12-02

申请号：US10878342

申请日：2004-06-29

发明人： Anthony Bessios ,  Jared Zerbe

IPC分类号： H04L025/34 ,  H04L027/06

CPC分类号： H04L25/4915 ,  H04L25/4919

摘要： A technique for utilizing spare bandwidth resulting from the use of a code in a multi-level signaling system is disclosed. In one particular exemplary embodiment, the technique may be realized as a method for utilizing spare bandwidth resulting from the use of a code in a multi-level signaling system, wherein the code has a characteristic wherein a signal transition is periodically unused. Such a method may comprise modifying the code such that the periodically unused signal transition is used to represent additional information.

摘要翻译： 公开了一种利用在多级信令系统中使用代码产生的备用带宽的技术。 在一个特定示例性实施例中，该技术可以被实现为用于利用由多级信令系统中的代码使用产生的备用带宽的方法，其中该代码具有周期性地不使用信号转换的特性。 这种方法可以包括修改代码，使得周期性地使用的信号转换用于表示附加信息。

公开(公告)号：US20040234009A1

公开(公告)日：2004-11-25

申请号：US10444338

申请日：2003-05-23

发明人： Mark Fimoff ,  Sreenivasa M. Nerayanuru ,  Serdar Ozen ,  Christopher J. Pladdy ,  Michael D. Zoltowski

IPC分类号： H04L027/06

CPC分类号： H04L25/03292 ,  H04L25/0212 ,  H04L25/0224 ,  H04L25/0244

摘要： A channel impulse response for a channel is determined by determining an initial channel impulse response estimate based upon a stored training sequence and a received signal, by thresholding the initial channel impulse response estimate, by estimating a noise variance for the channel based upon the stored training sequence, the thresholded initial channel impulse response estimate, and the received signal, by determining an inverse of a covariance matrix based on the estimated noise variance and the thresholded initial channel impulse response estimate, by updating the channel impulse response based on the inverse covariance matrix, the stored training sequence, and the received signal, and by thresholding the updated channel impulse response estimate.

摘要翻译： 通过基于所存储的训练来估计信道的噪声方差，通过阈值化初始信道脉冲响应估计来确定基于存储的训练序列和接收信号的初始信道脉冲响应估计来确定信道的信道脉冲响应 通过基于估计的噪声方差和阈值的初始信道脉冲响应估计来确定协方差矩阵的逆，通过基于逆协方差矩阵更新信道脉冲响应来确定阈值初始信道脉冲响应估计和接收信号 ，存储的训练序列和接收的信号，以及通过对更新的信道脉冲响应估计进行阈值处理。

公开(公告)号：US20040233090A1

公开(公告)日：2004-11-25

申请号：US10721550

申请日：2003-11-26

申请人： Oki Electric Industry Co., Ltd.

发明人： Tokio Miyasita ,  Sunao Mizunaga

IPC分类号： H03M001/12 ,  H04L027/06

CPC分类号： H04L25/062

摘要： A demodulating circuit includes a differentiating circuit that outputs a differentiated signal indicating voltage changes at rising and falling edges of a received pulse signal, and a hysteresis comparator that compares the differentiated signal with upper and lower threshold voltages, thereby generating a demodulated logic-level signal. The differentiating circuit can rapidly track variations in the direct-current offset of the received pulse signal. Positive feedback can enable the hysteresis comparator to maintain the correct output logic level during runs of 0's or 1's of arbitrary length in the received pulse signal. The demodulating circuit consumes comparatively little power, and is particularly useful for receiving signals transmitted in bursts.

摘要翻译： 解调电路包括：微分电路，输出表示接收到的脉冲信号的上升沿和下降沿的电压变化的微分信号;以及滞后比较器，其将微分信号与上限阈值电压和下限阈值电压进行比较，从而产生解调的逻辑电平信号 。 微分电路可以快速跟踪接收到的脉冲信号的直流偏移的变化。 正反馈可以使迟滞比较器在接收到的脉冲信号中的0或1任意长度的运行期间保持正确的输出逻辑电平。 解调电路消耗较少的功率，对于接收以突发方式发射的信号特别有用。

公开(公告)号：US20040218699A1

公开(公告)日：2004-11-04

申请号：US10427537

申请日：2003-04-30

申请人： MOTOROLA, INC.

发明人： Stephen R. Carsello

IPC分类号： H04L027/20 ,  H03D001/00 ,  H04L027/06

CPC分类号： H04L27/0014 ,  H04L7/027 ,  H04L7/042 ,  H04L7/06 ,  H04L2027/0026 ,  H04W52/0229 ,  H04W68/00

摘要： A wireless receiver 300 and corresponding method to detect a message identifier or preamble that has been generated and provided by a transmitter 200 uses FFTs to estimate frequency and time offset. The wireless receiver 300 scans, asynchronously and sequentially during a wakeup time, a plurality of predetermined frequencies for the message identifier or specialized preamble. A plurality of received sample sequences are collected, one received sample sequence collected at each of the plurality of predetermined frequencies. A correlation between data corresponding to the preamble and data corresponding to a received sample sequence is compared to a threshold value to determine when the preamble has been detected. The wireless receiver 300 is wakened from a low power mode when the preamble is detected.

摘要翻译： 无线接收机300和用于检测由发射机200产生和提供的消息标识符或前同步码的相应方法使用FFT来估计频率和时间偏移。 无线接收器300在唤醒时间期间异步地和顺序地扫描消息标识符或专用前同步码的多个预定频率。 收集多个接收的采样序列，在多个预定频率中的每一个处收集一个接收的采样序列。 对应于前导码的数据与对应于接收到的采样序列的数据之间的相关性与阈值进行比较，以确定何时检测到前导码。 当检测到前置码时，无线接收器300从低功率模式唤醒。

公开(公告)号：US20040213360A1

公开(公告)日：2004-10-28

申请号：US10423655

申请日：2003-04-25

发明人： Thomas P. McElwain

IPC分类号： H03D001/00 ,  H04L027/06

CPC分类号： H04L25/0204 ,  H04B1/7105 ,  H04B1/71052 ,  H04B1/71072 ,  H04L25/021 ,  H04L25/0242 ,  H04L25/03184 ,  H04L25/03216 ,  H04L25/0328 ,  H04L25/03292 ,  H04L25/03299 ,  H04L25/03331 ,  H04L2025/03401

摘要： The present invention provides an efficient means of estimating symbols transmitted in a multi-user environment in overloaded or super-saturated conditions by employing a deferred decorrelating decision feedback detector. In one embodiment, the present invention comprises a parameter estimation unit, filter bank, overloaded whitener and decision tree-based hypothesis testing. Parameter estimation defines the matched filter bank, whitening filters, and the terms of the hypothesis testing module. The whitening filter partially decouples co-channel interference and partially whitens the noise. The decision tree approach defers decisions until more evidence is accumulated and is a generalization that encompasses the jointly optimal maximum likelihood detector as well as the simpler decision feedback detectors.

摘要翻译： 本发明提供了一种通过使用延迟去相关决策反馈检测器来估计在超用或超饱和条件下在多用户环境中发送的符号的有效手段。 在一个实施例中，本发明包括参数估计单元，滤波器组，过载白化和基于决策树的假设检验。 参数估计定义了匹配滤波器组，白化滤波器和假设测试模块的项。 白化滤波器部分地解耦同信道干扰并部分地使噪声变白。 决策树方法延续决策，直到更多的证据被积累，并且是涵盖联合最佳最大似然检测器以及更简单的判决反馈检测器的泛化。

公开(公告)号：US20040213342A1

公开(公告)日：2004-10-28

申请号：US10785499

申请日：2004-02-24

发明人： Monisha Ghosh

IPC分类号： H04L027/06

CPC分类号： H04L1/0054 ,  H04L25/03057 ,  H04L2025/03382 ,  H04L2025/0349 ,  H04L2025/03617

摘要： A method and device for improving DFE performance in a trellis coded system by placing a short adaptive predictive filter after the DFE in order to whiten the error sequence at the output of the DFE.

摘要翻译： 一种通过在DFE之后放置一个短自适应预测滤波器来改善DFE输出端的误差序列来改善网格编码系统中DFE性能的方法和装置。

公开(公告)号：US20040208263A1

公开(公告)日：2004-10-21

申请号：US10839533

申请日：2004-05-05

申请人： Adtran, Inc.

发明人： Eric M. Rives ,  Matthew F. Gann ,  Anthony A. Goodloe

IPC分类号： H04L027/06 ,  H03D001/00 ,  H03D003/18

CPC分类号： H04L27/2332 ,  H04L2027/003 ,  H04L2027/0057

摘要： A digital data demodulator employs a cordic rotator-based, digital phase locked loop for carrier frequency tracking. Digitized I and Q channels downconverted to baseband using a fixed frequency oscillator are coupled to a digital cordic rotator. The cordic rotator iteratively executes pipelined phase-rotational adjustments of its digitized in-phase and quadrature inputs, in association with a pipelined reduction of the accumulated value of a phase angle vector code generated by digital phase error detection logic circuitry to which rotated I and Q outputs of the cordic rotator are applied. The phase error representative code vector is coupled through a digital loop filter as a reference angle input to the cordic rotator. The cordic rotator iteratively rotates the I and Q channel values that reduce the accumulated phase error to zero.