公开(公告)号：US07076010B1

公开(公告)日：2006-07-11

申请号：US09876201

申请日：2001-06-06

申请人： Sam Heidari ,  Raminder S. Bajwa ,  Behrooz Rezvani ,  Dale Smith ,  Prem Ramaswamy

发明人： Sam Heidari ,  Raminder S. Bajwa ,  Behrooz Rezvani ,  Dale Smith ,  Prem Ramaswamy

IPC分类号： H03K5/01

CPC分类号： H04B3/142 ,  H04L25/0216 ,  H04L25/03038 ,  H04L25/03133 ,  H04L2025/03414 ,  H04L2025/03585

摘要： The current invention provides a method and apparatus for time domain equalization in an XDSL modem. A received communication channel is analyzed to determine the highest frequency component thereof. Typically, there is an inverse relationship between the length of a subscriber line and the highest frequency component over which communications can be supported. In response to the frequency determination, the sampling rate for the channel is reduced to the lowest sample rate consistent with maintaining signal integrity on the highest frequency component of the channel. The sampling rate reduction may accomplished in the analog portion of the receive path, e.g. the analog-to-digital converter (ADC) or in a digital decimator coupled thereto. Concurrently the demodulator complexity is also scaled back. Where the XDSL protocol is digital multi-tone (DMT) the input sample size to the discrete Fourier transform (DFT) engine is reduced accordingly. With these adjustments in place TEQ resources may be scaled inversely. Thus as line length increases and the available bandwidth on the subscriber line is reduced more TEQ resources are made available to deal with the increased delay interval over which intersymbol interference is evidenced. Scaling of TEQ resources may be accomplished using a TEQ architecture which allows either the length or the tap line or the delay between taps to be varied.

摘要翻译： 本发明提供了一种用于XDSL调制解调器中时域均衡的方法和装置。 分析接收到的通信信道以确定其最高频率分量。 通常，用户线的长度与可以支持通信的最高频率分量之间存在反比关系。 响应于频率确定，信道的采样率降低到与在信道的最高频率分量上保持信号完整性一致的最低采样率。 可以在接收路径的模拟部分中实现采样率降低，例如， 模数转换器（ADC）或与之耦合的数字抽取器。 同时，解调器的复杂度也缩小了。 在XDSL协议是数字多音调（DMT）的情况下，离散傅里叶变换（DFT）引擎的输入采样大小相应减少。 通过这些调整，TEQ资源可能会相对缩小。 因此，当线路长度增加并且用户线路上的可用带宽减少时，更多的TEQ资源可用于处理增加的符号间干扰的延迟间隔。 TEQ资源的缩放可以使用允许长度或抽头线或抽头之间的延迟进行变化的TEQ架构来实现。

公开(公告)号：US07315571B1

公开(公告)日：2008-01-01

申请号：US09837914

申请日：2001-04-18

申请人： Sam Heidari ,  Behrooz Rezvani ,  Raminder S. Bajwa ,  Jacky Chow ,  Avadhani Shridhar ,  Dale Smith ,  John Gevargiz ,  Saman Behtash

发明人： Sam Heidari ,  Behrooz Rezvani ,  Raminder S. Bajwa ,  Jacky Chow ,  Avadhani Shridhar ,  Dale Smith ,  John Gevargiz ,  Saman Behtash

IPC分类号： H04B1/38

CPC分类号： H04L27/2628 ,  H04L5/0042 ,  H04L5/0044 ,  H04L5/0064 ,  H04L27/0002 ,  H04L27/265 ,  H04M11/062

摘要： A transceiver for communicating a multi-tone modulated communication channel on a subscriber line. The transceiver includes: a digital signal processor (DSP) with a Fourier transform module and an analog front end (AFE). The DSP determines an available range of frequencies on the subscriber line and expands or contracts the tone spacing of each of a fixed number “N” of tones accordingly by decreasing or increasing the processing interval associated with the Fourier transform of each tone set. The AFE performs digital-to-analog conversion of the multi-tone modulated communication channel at rates compatible with the processing interval of the Fourier transform module; whereby the range of frequencies spanned by the modulated tones on the subscriber line conforms to the available of frequencies on the subscriber line.

摘要翻译： 用于在用户线路上传送多音调调制通信信道的收发器。 收发器包括：具有傅立叶变换模块和模拟前端（AFE）的数字信号处理器（DSP）。 DSP确定用户线路上的可用频率范围，并通过减少或增加与每个音调集合的傅里叶变换相关联的处理间隔来相应地扩展或收缩固定数量“N”个音调中的每一个的音调间隔。 AFE以与傅里叶变换模块的处理间隔兼容的速率执行多音调调制通信信道的数模转换; 由此用户线路上的调制音调跨越的频率范围符合用户线上的可用频率。

公开(公告)号：US06940807B1

公开(公告)日：2005-09-06

申请号：US09699193

申请日：2000-10-26

申请人： Behrooz Rezvani ,  Avadhani Shridhar ,  Raminder S. Bajwa ,  Tiruvur R. Ramesh ,  Masoud Eskandari ,  Firooz Massoudi ,  Sam Heidari ,  Omprakash S. Sarmaru ,  Sridhar Begur

发明人： Behrooz Rezvani ,  Avadhani Shridhar ,  Raminder S. Bajwa ,  Tiruvur R. Ramesh ,  Masoud Eskandari ,  Firooz Massoudi ,  Sam Heidari ,  Omprakash S. Sarmaru ,  Sridhar Begur

IPC分类号： H04J11/00

CPC分类号： G06F17/142 ,  H04L27/2628 ,  H04L27/265

摘要： The current invention provides a DSP which accommodates multiple current X-DSL protocols and is further configurable to support future protocols. The DSP is implemented with shared and dedicated hardware components on both the transmit and receive paths. The DSP implements both the discrete Fourier transform (DFT) and inverse discrete Fourier transform (IDFT) portions across a wide range of sample sizes and X-DSL protocols. Multiple channels, each with varying ones of the X-DSL protocols can be handled in the same session. The DSP offers the speed associated with hardware implementation of the transforms and the flexibility of a software only implementation. Traffic flow is regulated in the chip using a packet based schema in which each packet is associated with a specific channel of upstream and downstream data. Header and control information in each packet is used to govern the processing of each packet as it moves along either the transmit path or receive path. The DSP of the current invention may advantageously be utilized in fields other than communications, such as: medical and other imaging, seismic analysis, radar and other military applications, pattern recognition, signal processing etc. The present invention provides a signal processing architecture that supports scalability of CO/DLC/ONU resources, and allows a significantly more flexible hardware response to the evolving X-DSL standards without over committing of hardware resources. As standards evolve hardware may be reconfigured to support the new standards.

摘要翻译： 本发明提供一种DSP，其容纳多个当前的X-DSL协议，并且可进一步配置以支持未来的协议。 DSP在传输和接收路径上都具有共享和专用硬件组件。 DSP在宽范围的采样大小和X-DSL协议上实现离散傅立叶变换（DFT）和离散傅立叶逆变换（IDFT）部分。 每个具有不同的X-DSL协议的多个信道可以在同一个会话中处理。 DSP提供与转换的硬件实现相关的速度和仅用于软件的实现的灵活性。 使用基于分组的模式在芯片中调整流量流，其中每个分组与上游和下游数据的特定信道相关联。 每个数据包中的报头和控制信息用于控制每个数据包沿着发送路径或接收路径移动时的处理。 本发明的DSP可有利地用于通信以外的领域，例如：医疗和其他成像，地震分析，雷达和其他军事应用，模式识别，信号处理等。本发明提供一种信号处理架构，其支持 CO / DLC / ONU资源的可扩展性，并且允许对演进的X-DSL标准的显着更灵活的硬件响应，而不必超过硬件资源。 随着标准的发展，硬件可能被重新配置以支持新的标准。

公开(公告)号：US06963603B1

公开(公告)日：2005-11-08

申请号：US09876263

申请日：2001-06-06

申请人： Behrooz Rezvani ,  Sam Heidari ,  Dale Smith

发明人： Behrooz Rezvani ,  Sam Heidari ,  Dale Smith

IPC分类号： H04B1/38 ,  H04B3/56

CPC分类号： H04B3/56 ,  H04B2203/5408 ,  H04B2203/5425 ,  H04B2203/5491 ,  H04L5/0007 ,  H04L5/0042 ,  H04L5/0044 ,  H04L5/006 ,  H04L5/008 ,  H04L25/03159 ,  H04L25/03343 ,  H04L2025/03414 ,  H04L2025/03522 ,  H04L2025/03802

摘要： An apparatus and method is provided for minimizing frequency distortion in the transmit path of an XDSL modem implementing digital multi-tone (DMT) line code. The current invention provides a means for both determining and correcting for distortion in the frequency domain. The apparatus may be incorporated in an existing X-DSL architecture without additional circuitry. In an embodiment of the invention the apparatus may include a calibration phase which may be implemented using the existing analog-to-digital (ADC) conversion and demodulation capabilities on the receive path of the modem. This calibration phase takes place before the training phase associated with establishing communications with a remote site. During the calibration phase a calibration sequence with known spectral characteristics in the frequency domain is injected digitally at the beginning of the transmit path into each of the tone bins of the inverse Fourier Transform engine (IFFT). The receive path is configured to receive feedback of a resultant analog output signal from the transmit path. A frequency analyzer is used to determine the spectral properties of the feedback from the analog output signal and a normalizer is used to compute a local gain table with gain factors for each tone bin which effect the required normalization.

摘要翻译： 提供了一种用于最小化实现数字多音（DMT）线路码的XDSL调制解调器的发送路径中的频率失真的装置和方法。 本发明提供了一种用于确定和校正频域中的失真的装置。 该装置可以并入现有的X-DSL架构中，而不需要附加的电路。 在本发明的实施例中，该装置可以包括校准阶段，其可以使用在调制解调器的接收路径上的现有模数（ADC）转换和解调能力来实现。 该校准阶段在与远程站点建立通信相关联的训练阶段之前进行。 在校准阶段期间，在频域中具有已知频谱特性的校准序列在发射路径的开始被数字地注入到逆傅里叶变换引擎（IFFT）的每个音调块中。 接收路径被配置为从发送路径接收所得到的模拟输出信号的反馈。 使用频率分析器来确定来自模拟输出信号的反馈的频谱特性，并且使用归一化器来计算具有影响所需归一化的每个音调单元的增益因子的局部增益表。

公开(公告)号：US07028063B1

公开(公告)日：2006-04-11

申请号：US09698824

申请日：2000-10-26

申请人： Omprakash S. Sarmaru ,  Raminder S. Bajwa ,  Sridhar Begur ,  Avadhani Shridhar ,  Sam Heid Ari ,  Behrooz Rezvani

发明人： Omprakash S. Sarmaru ,  Raminder S. Bajwa ,  Sridhar Begur ,  Avadhani Shridhar ,  Sam Heid Ari ,  Behrooz Rezvani

IPC分类号： F06F17/14

CPC分类号： G06F17/141 ,  H04L27/2628 ,  H04L27/265

摘要： A Fourier transform processor utilizing discrete circuits each of which is configurable for processing a wide range of sample sizes. A single pipeline supports multiplexed bi-directional transformations between for example the time and frequency domains. In an embodiment of the invention the Fourier Transform processor may be implemented as part of a digital signal processor (DSP). In this embodiment the DSP may implement both the discrete Fourier transform (DFT) and inverse discrete Fourier transform (IDFT) across a wide range of sample sizes and X-DSL protocols. Multiple channels, each with varying ones of the X-DSL protocols can be handled in the same session.

摘要翻译： 利用离散电路的傅里叶变换处理器，每个离散电路可配置用于处理各种样本大小的范围。 单个流水线支持例如时域和频域之间的复用双向变换。 在本发明的实施例中，傅里叶变换处理器可以被实现为数字信号处理器（DSP）的一部分。 在该实施例中，DSP可以在宽范围的样本大小和X-DSL协议上实现离散傅里叶变换（DFT）和离散傅里叶逆变换（IDFT）两者。 每个具有不同的X-DSL协议的多个信道可以在同一个会话中处理。

公开(公告)号：US06959036B1

公开(公告)日：2005-10-25

申请号：US09776067

申请日：2001-02-02

申请人： Behrooz Rezvani ,  Dale Smith ,  Sam Heidari ,  Homayoun Shahri

发明人： Behrooz Rezvani ,  Dale Smith ,  Sam Heidari ,  Homayoun Shahri

IPC分类号： H04B1/38 ,  H04L12/56 ,  H04L25/49 ,  H04L27/00 ,  H04L27/26

CPC分类号： H04L27/0012 ,  H04L25/4921 ,  H04L27/2601 ,  H04L2012/5652

摘要： An X-DSL modem supporting multiple X-DSL line codes including discrete multi-tone (DMT) and carrierless phase and amplitude (CAP). The modem includes: components coupled to one another to form a transmit path and a receive path. The components include an encoder component and a Fourier transform component. The encoder component encodes data associated with a CAP communication channel into QAM symbols and encodes data associated with a DMT communication channel into DMT sub-symbols. The Fourier transform component couples to the encoder component on the transmit path for transforming DMT sub-symbols from a frequency-to-time domain and for transforming QAM symbols from the time-to-frequency domain followed by a filtering in the frequency domain and a subsequent transformation back from the frequency-to-time domain to effect a pulse shaping function without requiring a discrete pulse shaping component in the transmit path.

摘要翻译： 支持多个X-DSL线路码的X-DSL调制解调器，包括离散多音（DMT）和无载波相位和幅度（CAP）。 调制解调器包括：彼此耦合以形成发送路径和接收路径的组件。 组件包括编码器组件和傅里叶变换组件。 编码器部件将与CAP通信信道相关联的数据编码为QAM符号，并将与DMT通信信道相关联的数据编码为DMT子符号。 傅立叶变换分量耦合到发送路径上的编码器部件，用于从频域转换DMT子符号，并用于从时域到频域变换QAM符号，随后在频域中进行滤波，并且 从频域到时域的后续变换，以实现脉冲整形功能，而不需要发射路径中的离散脉冲整形分量。

公开(公告)号：US06392579B1

公开(公告)日：2002-05-21

申请号：US09859196

申请日：2001-05-14

申请人： Behrooz Rezvani ,  Dale Smith ,  Sam Heidari

发明人： Behrooz Rezvani ,  Dale Smith ,  Sam Heidari

IPC分类号： H03M166

CPC分类号： H03H17/0664

摘要： An apparatus and method is disclosed for a digital-to-analog converter (DAC) system with both uniform and non-uniform sampling rates. The system includes a digital portion in which samples of a set of “N” digital samples are obtained from a digital input stream. Each set of samples is evaluated with various test decimations which may include various combinations of uniform and non-uniform timing intervals between the selected members of each decimation. Each test decimation includes substantially the same number “M” of digital samples where “M” is less than the number of samples “N” in each sample set. Each test decimation is digitally evaluated to determine which is the optimum test decimation. The optimum test decimation exhibits the best fit with the original set of “N” samples using a reduced set of “M” digital samples. This optimum test decimation along with the appropriate timing information is subject to an digital-to-analog conversion, with the corresponding analog output signal retaining a high degree of fidelity with the digital input signal albeit at a reduced average sampling rate. The reduction in sampling rate for the DAC simplifies circuit design and reduces power requirements.

摘要翻译： 公开了一种具有均匀和非均匀采样率的数模转换器（DAC）系统的装置和方法。 该系统包括数字部分，其中从数字输入流获得一组“N”个数字样本的采样。 用各种测试抽取来评估每组样本，其可以包括在每个抽取的所选择的成员之间的均匀和不均匀的定时间隔的各种组合。 每个测试抽取包括基本上相同数量的“M”数字样本，其中“M”小于每个样本集中的样本数“N”。 对每个测试抽取进行数字评估，以确定哪个是最佳测试抽取。 最佳测试抽取使用一组缩减的“M”数字样本与“N”个样本的原始集合展现出最佳匹配。 这种最佳测试抽取以及适当的定时信息经受数模转换，相应的模拟输出信号保持与数字输入信号的高度保真度，尽管平均采样率降低。 DAC的采样率的降低简化了电路设计并降低了功耗要求。

公开(公告)号：US06985521B1

公开(公告)日：2006-01-10

申请号：US09779789

申请日：2001-02-07

申请人： Behrooz Rezvani ,  Sam Heidari ,  Dale Smith

发明人： Behrooz Rezvani ,  Sam Heidari ,  Dale Smith

IPC分类号： H04B1/38 ,  H03D1/00

CPC分类号： H04B3/46 ,  H04B3/487

摘要： An apparatus and method is disclosed for channel estimation in an X-DSL communication device. The communication device may include physical or logical modems. The modems may implement one or more of a group of X-DSL protocols including: G.Lite, ADSL, VDSL, and HDSL. The apparatus may be used for determining the location and magnitude of discontinuities or faults within the communication medium to which the X-DSL communication device is coupled. The information provided by the device may be used for line qualification or repair. No additional equipment is required for channel estimation. Instead the apparatus may be located within a single modem or shared between a group of modems. An N bit pseudo random codeword injected into the transmit path is used to generate both a leakage signal and a plurality of reflected signals on the receive path. No timing information is needed from the transmit path. Instead a unique correlator is utilized on the receive path to extract timing information for the reflected signals relative to the leakage signal. The broad bandwidth of the codeword and its relatively long duration allow channel estimation at significantly higher signal-to-noise ratios and with greater degrees of accuracy than heretofore possible.

摘要翻译： 公开了一种用于X-DSL通信设备中的信道估计的装置和方法。 通信设备可以包括物理或逻辑调制解调器。 调制解调器可以实现一组X-DSL协议中的一个或多个，包括：G.Lite，ADSL，VDSL和HDSL。 该装置可以用于确定X-DSL通信设备耦合到的通信介质内的不连续性或故障的位置和大小。 该设备提供的信息可用于线路鉴定或维修。 信道估计不需要额外的设备。 相反，装置可以位于单个调制解调器内或在一组调制解调器之间共享。 注入到发送路径中的N位伪随机码字用于在接收路径上产生泄漏信号和多个反射信号。 从发送路径不需要定时信息。 相反，在接收路径上利用唯一的相关器来提取相对于泄漏信号的反射信号的定时信息。 码字的宽带宽及其相对较长的持续时间允许以比以前更高的信噪比和更高的准确度进行信道估计。

公开(公告)号：US06873653B1

公开(公告)日：2005-03-29

申请号：US09779256

申请日：2001-02-07

申请人： Behrooz Rezvani ,  Sam Heidari ,  John Zhongxuan Zhang ,  Dale Smith

发明人： Behrooz Rezvani ,  Sam Heidari ,  John Zhongxuan Zhang ,  Dale Smith

IPC分类号： H04L5/16 ,  H04L27/26

CPC分类号： H04L5/16 ,  H04L27/2601

摘要： An apparatus and method is provided for minimizing in channel distortion in an X-DSL line driver is disclosed. The apparatus may be incorporated in an existing X-DSL architecture without additional circuitry. Out of band monitoring of a channel is implemented to adaptively minimize out of band interference and in band distortion. A unique training sequence, suitable for DMT line codes is set forth. The training sequence allows a full spectral characterization of the downstream signal space with a single upstream monitoring tone. The invention may be used with multi-channel X-DSL line drivers interfacing with any of a number of multi-channel supply architectures. The apparatus may be applied with equal advantage to communication protocols other than X-DSL. The apparatus may be applied with equal advantage in wired and wireless media.

摘要翻译： 提供了一种用于最小化X-DSL线路驱动器中的信道失真的装置和方法。 该装置可以并入现有的X-DSL架构中，而不需要附加的电路。 实现频带的带外监视以自适应地最小化带外干扰和带内失真。 阐述了适用于DMT线路码的唯一训练序列。 训练序列允许使用单个上游监控音调对下游信号空间的全频谱表征。 本发明可以与与多个多信道供应架构中的任何一个接口的多信道X-DSL线路驱动器一起使用。 该装置可以与除了X-DSL之外的通信协议相同的优点。 该装置可以在有线和无线介质中具有相同的优点。

公开(公告)号：US07075998B1

公开(公告)日：2006-07-11

申请号：US09779788

申请日：2001-02-07

申请人： Behrooz Rezvani ,  Sam Heidari ,  Dale Smith ,  Reuven Segev

发明人： Behrooz Rezvani ,  Sam Heidari ,  Dale Smith ,  Reuven Segev

IPC分类号： H04L27/28

CPC分类号： H04L5/143 ,  H04L5/026

摘要： A method and apparatus for communicating multi-tone modulated upstream and downstream channels of communication data between a pair of communication devices utilizing a common set of tones for the upstream and downstream channels. The pair of communication devices each include a digital stage configured to assign mutually orthogonal code sequences for encoding and decoding the upstream and downstream channel respectively. The transmit path of the digital stage of each communication device is configured to generate redundancy in the associated communication data in either the time or frequency domain and to encode the redundant communication data with the mutually orthogonal code sequence prior to transmission thereby allowing the communication devices to share a common frequency spectrum of a communication medium for the upstream and downstream communication channels.

摘要翻译： 一种用于在利用用于上游和下游信道的公共音调集合的一对通信设备之间通信多音调调制上行和下行信道的通信数据的方法和装置。 该对通信装置各自包括被配置为分配用于对上游和下游信道进行编码和解码的相互正交的码序列的数字级。 每个通信设备的数字级的发送路径被配置为在时域或频域中产生相关联的通信数据中的冗余，并且在发送之前用相互正交的码序列对冗余通信数据进行编码，从而允许通信设备 共享用于上游和下游通信信道的通信介质的公共频谱。