公开(公告)号：US20060221808A1

公开(公告)日：2006-10-05

申请号：US11395153

申请日：2006-04-03

申请人： Naganori Shirakata ,  Koichiro Tanaka ,  Shuya Hosokawa

发明人： Naganori Shirakata ,  Koichiro Tanaka ,  Shuya Hosokawa

IPC分类号： H04J11/00

CPC分类号： H04B7/0848 ,  H04L1/0048 ,  H04L1/06 ,  H04L5/026 ,  H04L25/03159 ,  H04L27/2657 ,  H04L27/2675 ,  H04L2025/03414 ,  H04L2025/03426 ,  H04L2027/003 ,  H04L2027/0048 ,  H04L2027/0067 ,  H04L2027/0087

摘要： OFDM signals each including a plurality of subcarriers (including data carriers and pilot carriers) orthogonal to each other are received by a plurality of receiver antennas. The received OFDM signals are each OFDM-demodulated into a plurality of receive subcarriers. Based on the plurality of receive subcarriers, the propagation coefficients of a plurality of space paths are estimated. An inverse matrix of a propagation matrix whose elements are the estimated propagation coefficients is calculated. Interference cancellation is performed for the plurality of receive subcarriers by using the inverse matrix, and transmit subcarriers multiplexed in space are estimated. A reliability of the inverse matrix is calculated. A pilot carrier is extracted from the estimated transmit subcarriers, and the extracted pilot carrier is weighted according to the reliability. An error included in the plurality of receive subcarriers is corrected based on the weighted pilot carrier.

摘要翻译： 每个包括彼此正交的多个子载波（包括数据载波和导频载波）的OFDM信号由多个接收机天线接收。 所接收的OFDM信号被OFDM解调成多个接收子载波。 基于多个接收子载波，估计多个空间路径的传播系数。 计算其元素是估计传播系数的传播矩阵的逆矩阵。 通过使用逆矩阵对多个接收子载波执行干扰消除，并且估计在空间中复用的发送子载波。 计算逆矩阵的可靠性。 从估计的发射子载波中提取导频载波，并根据可靠性对所提取的导频载波进行加权。 基于加权导频载波来校正包含在多个接收子载波中的误差。

公开(公告)号：US07110476B1

公开(公告)日：2006-09-19

申请号：US09510861

申请日：2000-02-23

申请人： Koichi Tamura

发明人： Koichi Tamura

IPC分类号： H03D3/18

CPC分类号： H04L27/0014 ,  H04L7/042 ,  H04L27/2332 ,  H04L2027/0065 ,  H04L2027/0067 ,  H04L2027/0087 ,  H04L2027/0095

摘要： A demodulation circuit and a demodulation method can optimize sampling timing with achieving reduction of power consumption. A preliminarily known signal is inserted in the digital transmission signal upon transmission. The demodulation circuit includes A/D converting means for performing A/D conversion of a base band signal obtained by demodulation of the digital transmission signal, and phase shifting means for causing phase shift of one of the digital transmission signal and the base band signal on the basis of the known signal after digital conversion by the A/D converting means and the known signal upon transmission.

摘要翻译： 解调电路和解调方法可以优化采样时序，实现功耗的降低。 在传输时，将数字传输信号插入预先知道的信号。 解调电路包括A / D转换装置，用于对通过解调数字传输信号获得的基带信号进行A / D转换;以及相移装置，用于使数字传输信号和基带信号之一相移 通过A / D转换装置数字转换之后的已知信号的基础和传输时的已知信号。

公开(公告)号：US07095707B2

公开(公告)日：2006-08-22

申请号：US09759842

申请日：2001-01-12

申请人： Selim Shlomo Rakib ,  Yehuda Azenkot

发明人： Selim Shlomo Rakib ,  Yehuda Azenkot

IPC分类号： H04J9/00

CPC分类号： H04W48/16 ,  H03M13/256 ,  H03M13/39 ,  H03M13/41 ,  H04B1/1027 ,  H04B1/707 ,  H04B1/7087 ,  H04B7/2668 ,  H04B2201/709709 ,  H04H20/77 ,  H04H20/78 ,  H04J3/0602 ,  H04J3/0608 ,  H04J3/0638 ,  H04J3/0682 ,  H04J13/00 ,  H04J13/004 ,  H04J14/007 ,  H04L1/006 ,  H04L1/16 ,  H04L5/023 ,  H04L5/026 ,  H04L5/06 ,  H04L7/041 ,  H04L12/2801 ,  H04L25/03057 ,  H04L25/03343 ,  H04L25/4921 ,  H04L27/0014 ,  H04L27/2656 ,  H04L27/2657 ,  H04L27/2662 ,  H04L27/362 ,  H04L2025/03414 ,  H04L2027/0083 ,  H04L2027/0087 ,  H04N7/10 ,  H04N7/17309 ,  H04N7/54 ,  H04N21/2221 ,  H04N21/2408 ,  H04N21/4305 ,  H04N21/4383 ,  H04W24/00 ,  H04W56/00 ,  H04W74/0866

摘要： A system for bidirectional communication of digital data between a central unit and a remote unit wherein the need for tracking loops in the central unit has been eliminated. The central unit transmitter generates a master carrier and a master clock signal which are used to transmit downstream data to the remote units. The remote units recover the master carrier and master clock and synchronize local oscillators in each remote unit to these master carrier and master clock signals to generate reference carrier and clock signals for use by the remote unit receiver. These reference carrier and clock signals are also used by the remote unit transmitters to transmit upstream data to the central unit. The central unit receiver detects the phase difference between the reference carrier and clock signals from the remote units periodically and adjusts the phase of the master carrier and master clock signals for use by the central unit receiver to receive the upstream data.

公开(公告)号：US07038730B2

公开(公告)日：2006-05-02

申请号：US10192039

申请日：2002-07-10

申请人： Ivonete Markman ,  Gabriel Alfred Edde

发明人： Ivonete Markman ,  Gabriel Alfred Edde

IPC分类号： H04N5/21 ,  H04N5/213 ,  H04N5/217

CPC分类号： H04L25/061 ,  H04L25/03834 ,  H04L2027/0087 ,  H04N5/21 ,  H04N5/4401

摘要： A communications receiver receives a signal which has not been filtered by a matched pulse shaping filter. In the receiver, a circuit element processes the received signal and as a part of that process introduces additional linear distortion into the processed received signal. A matched filter, coupled to the circuit element, generates a fully matched filtered signal compensated for the distortion intrinsic to the received signal pulse shape and the distortion introduced by the circuit element.

摘要翻译： 通信接收器接收未被匹配的脉冲整形滤波器滤波的信号。 在接收机中，电路元件处理接收到的信号，并且作为该处理的一部分，对经处理的接收信号引入附加的线性失真。 耦合到电路元件的匹配滤波器产生补偿了接收信号脉冲形状固有的失真和由电路元件引入的失真的完全匹配的滤波信号。

公开(公告)号：US20050117665A1

公开(公告)日：2005-06-02

申请号：US11028158

申请日：2005-01-03

申请人： Burkhard Becker ,  Holger Neuhaus

发明人： Burkhard Becker ,  Holger Neuhaus

IPC分类号： H03K9/00 ,  H04B7/26 ,  H04L27/00 ,  H04L27/14

CPC分类号： H04L27/14 ,  H04L2027/0067 ,  H04L2027/0087 ,  H04W56/0035 ,  H04W92/10

摘要： A device for determination of the frequency discrepancy (105) between a mobile radio and a base station which is transmitting a sequence of symbols, having a unit (6-11) for calculation of terms, with one term being formed from two symbols in the sequence received by the mobile radio, and in which case the phase difference of the two symbols can be determined from the term, a unit (14, 15) for formation of groups from the terms, with one term being assigned to one group on the basis of features of the symbols on which it is based, and a unit (39) for calculation of the discrepancy (105) on the basis of a group.

摘要翻译： 一种用于确定正在发送具有用于计算术语的单元（6-11）的符号序列的移动无线电和基站之间的频率差异（105）的装置，其中一个术语由 在这种情况下，两个符号的相位差可以从该术语确定，用于从术语形成组的单元（14,15），其中一个术语被分配给一个组 基于其所基于的符号的特征的基础，以及用于基于组来计算差异（105）的单元（39）。

公开(公告)号：US20050105651A1

公开(公告)日：2005-05-19

申请号：US11031107

申请日：2005-01-07

申请人： Steven Jaffe ,  Tian-Min Liu ,  Loke Tan

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

IPC分类号： H04B1/68 ,  H04L25/03 ,  H04L27/00 ,  H04L27/02 ,  H04L27/06 ,  H04L27/227 ,  H04L27/34 ,  H04L27/38 ,  H04N5/21 ,  H04N5/44 ,  H04N5/46 ,  H04N11/00 ,  H04L27/14

CPC分类号： H04N21/4382 ,  H04B1/68 ,  H04L25/03057 ,  H04L27/02 ,  H04L27/066 ,  H04L27/2273 ,  H04L27/3427 ,  H04L27/3827 ,  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： A television receiver system capable of receiving and demodulating television signal information content that has been modulated and transmitted in accordance with a variety of modulation formats is disclosed. In particular, the system is able to accommodate receipt and demodulation of at least 8 and 16-VSB modulated signals in order to support US HDTV applications, as well as 64 and 256-QAM modulated signals, for European and potential US CATV implementations. The system includes carrier and timing recovery loops adapted to operate on an enhanced pilot signal as well as decision directed carrier phase recovery loops. Phase detectors operate on I and Q rail signals, or generate a Q rail from a Hilbert transform of the I rail. Decision directed loops incorporate a trellis decoder in order to operate on sequence estimated decisions for improved reliability in poor SNR environments.

公开(公告)号：US06856648B1

公开(公告)日：2005-02-15

申请号：US09617813

申请日：2000-07-17

申请人： Mattias Hyll

发明人： Mattias Hyll

IPC分类号： H04L25/03 ,  H04L27/00 ,  H04L27/26 ,  H03H7/30 ,  H03H7/40 ,  H03K5/159

CPC分类号： H04L25/03159 ,  H04L27/2655 ,  H04L27/2675 ,  H04L27/2679 ,  H04L2025/03522 ,  H04L2027/0038 ,  H04L2027/0055 ,  H04L2027/0063 ,  H04L2027/0087

摘要： Equalizer updating and accurate sampling rate control in a DMT receiver are simultaneously performed using a known signal, such as a pilot tone. The known signal is separated into its real and imaginary components. The equalizer uses separate mechanisms to process the real and imaginary components. The real component is used to control sampling rate timing in the receiver. The imaginary component of the received signal is used in an equalization adaptation procedure, e.g., updating an equalizer coefficient value. In one example embodiment, the real component of the received signal is set to zero for purposes of equalization, and the unequalized, real component is used to recover/track sampling rate timing. Because the real component has not been equalized, simultaneous timing recovery/tracking and equalization is achieved. Only the imaginary component is equalized and used to update the equalizer coefficient value. Thereafter, the unequalized real component and the equalized imaginary component are combined. In another example embodiment, a real-valued equalizer coefficient is determined for the known signal. Both real and imaginary components of the known sigal are equalized with the real-valued equalizer coefficient. The so-equalized real component adapts to a normalized amplitude for the timing control signal which is desirable in certain timing control applications. The equalized real and imaginary components are combined. The equalizer coefficient is updated using only the imaginary component of the received signal.

摘要翻译： DMT接收机中的均衡器更新和精确的采样率控制使用已知的信号（例如导频音）同时进行。 已知信号被分成其实部和虚部。 均衡器使用单独的机制来处理实部和虚部。 实际组件用于控制接收机中的采样率定时。 接收信号的虚分量用于均衡适配过程，例如更新均衡器系数值。 在一个示例实施例中，为了均衡的目的，接收信号的实部分数被设置为零，并且使用不等的实部分来恢复/跟踪采样率定时。 由于实际分量未被均衡，因此实现了同步定时恢复/跟踪和均衡。 只有虚分量被均衡并用于更新均衡器系数值。 此后，组合了无与伦比的实数分量和均衡虚分量。 在另一示例实施例中，为已知信号确定实值均衡器系数。 已知Sigal的实部和虚部均与实数均衡器系数相等。 均衡的实部组件适应于定时控制信号的归一化幅度，其在某些定时控制应用中是期望的。 均衡的实部和虚部组合。 仅使用接收信号的虚分量来更新均衡器系数。

公开(公告)号：US06842488B2

公开(公告)日：2005-01-11

申请号：US09794159

申请日：2001-02-28

申请人： Ji-sung Oh

发明人： Ji-sung Oh

IPC分类号： H04L27/02 ,  H04L27/00 ,  H04L27/06 ,  H04L27/22 ,  H04L27/38 ,  H04L23/02

CPC分类号： H04L27/0008 ,  H04L27/066 ,  H04L27/3854 ,  H04L2027/0036 ,  H04L2027/0055 ,  H04L2027/0087

摘要： A vestigial sideband/quadrature amplitude modulation (VSB/QAM) receiver, which receives both VSB and QAM signals and restores a carrier wave with a restored symbol clock after restoring a symbol timing in a front portion of a carrier wave restoration unit. The receiver has an analog-digital converter for A/D converting in accordance with a frequency higher than a symbol frequency of a received signal; an interpolator for calculating a signal value on the original symbol location after a signal from the A/D converter is applied; the carrier wave restoration unit for restoring a carrier wave by selectively using an automatic frequency control (AFC) and a digital frequency phase locked loop (DFPLL) in accordance with a VSB/QAM mode after a signal from the interpolator is applied; a timing processor for receiving a signal from the carrier wave restoration unit, detecting a timing error after changing a symbol input time in accordance with a VSB/QAM mode, controlling the interpolator based on the detected timing error, and generating a restored clock; and a VSB sorter for extracting a VSB receiving symbol.

摘要翻译： 一种残留边带/正交幅度调制（VSB / QAM）接收机，其在恢复载波恢复单元的前部中的符号定时之后接收VSB和QAM信号并恢复具有恢复的符号时钟的载波。 接收器具有用于根据接收信号的符号频率高的频率进行A / D转换的模数转换器; 用于在应用来自A / D转换器的信号之后计算原始符号位置上的信号值的内插器; 载波恢复单元，用于在应用来自内插器的信号之后，通过选择性地使用根据VSB / QAM模式的自动频率控制（AFC）和数字频率锁相环（DFPLL）来恢复载波; 定时处理器，用于从载波恢复单元接收信号，根据VSB / QAM模式检测符号输入时间改变后的定时误差，根据检测到的定时误差控制内插器，并产生恢复时钟; 以及用于提取VSB接收符号的VSB分类器。

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：US06771714B2

公开(公告)日：2004-08-03

申请号：US10150186

申请日：2002-05-16

申请人： Tian-Min Liu ,  Loke Kun Tan ,  Steven T. Jaffe

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

IPC分类号： H04L2714

CPC分类号： H04N5/21 ,  H04B1/68 ,  H04L25/03057 ,  H04L27/02 ,  H04L27/066 ,  H04L27/2273 ,  H04L27/3427 ,  H04L27/3827 ,  H04L2025/03382 ,  H04L2025/0342 ,  H04L2025/0349 ,  H04L2025/03503 ,  H04L2027/0032 ,  H04L2027/0042 ,  H04L2027/0057 ,  H04L2027/0067 ,  H04L2027/0087 ,  H04N5/211 ,  H04N5/44 ,  H04N5/4401 ,  H04N5/455 ,  H04N5/46 ,  H04N11/002

摘要： Improved carrier recovery and symbol timing systems and methods suitable for use in connection with a dual-mode QAM/VSB receiver system is disclosed. Carrier and symbol timing acquisition and tracking loops are phase/frequency locked to an inserted pilot signal provided in an input VSB spectrum at a given frequency. An input spectrum is centered about baseband and the pilot is extracted by an equivalent filter which functions as a bandpass filter having pass bands centered about the pilot frequency. Since the pilot signal's frequency is given, its position in the frequency domain for any sampling frequency, is deterministic. The receiver's sampling frequency is provided such that the relationship is expressed as fc=fs/4. When tracked by a phase-lock loop, the pilot signal will appear at the correct location in the spectrum if the sampling frequency fs is correct, and will be shifted in one direction or the other if the sampling frequency fs is too high or too low.

摘要翻译： 公开了适用于双模QAM / VSB接收机系统的改进的载波恢复和符号定时系统和方法。 载波和符号定时采集和跟踪环路被相位/频率锁定到在给定频率下在输入VSB频谱中提供的插入导频信号。 输入频谱以基带为中心，并且通过等效滤波器提取导频，该等效滤波器用作具有以导频频率为中心的通带的带通滤波器。 由于给出了导频信号的频率，所以在频域中对于任何采样频率的位置是确定性的。 提供接收机的采样频率，使得该关系被表示为fc = fs / 4。 当通过锁相环路进行跟踪时，如果采样频率fs正确，则导频信号将出现在频谱中的正确位置，并且如果采样频率fs太高或太低，则导频信号将在一个方向或另一个方向上移位 。