公开(公告)号：US5757300A

公开(公告)日：1998-05-26

申请号：US734906

申请日：1996-10-22

申请人： Ravinder David Koilpillai ,  David Byrd Ribner ,  Jerome Johnson Tiemann

发明人： Ravinder David Koilpillai ,  David Byrd Ribner ,  Jerome Johnson Tiemann

IPC分类号： H03M3/02 ,  H03M3/00

CPC分类号： H03M3/456 ,  H03M3/406 ,  H03M3/43

摘要： Delta sigma modulators for accepting input signals having amplitudes up to -1 dB of full-scale and a center frequency (F.sub.S) in the range �F.sub.S /90, 44F 90!, and which are not prone to internal overflow, require few circuit parameters, and yield a signal transfer function with the inherent property that the modulator magnitude response is close to unity gain in the frequency region of interest include, in one embodiment, a pair of cascaded integrators, a unit delay element coupled to the output of the second integrator, an analog-to-digital (A/D) converter, and a one-bit digital-to-analog (D/A) converter controlled by output signals from the A/D converter. A first differential summing junction coupled to the output of the D/A converter is responsive to delta sigma modulator input signals. A second differential summing junction, coupled to the output of the first differential summing junction, is also coupled to receive a feedback signal from the second integrator. A third differential summing junction, coupled to the output of the unit delay element, also receives feed-forward signals from the second integrator.

摘要翻译： 用于接受具有高达-1dB的满量程的输入信号和在[FS / 90,44F 90]范围内且不易于内部溢出的中心频率（FS）的ΔΣ调制器需要很少的电路参数 ，并且产生具有固有特性的信号传递函数，调制器幅度响应在感兴趣的频率区域中接近于单位增益，在一个实施例中包括一对级联积分器，单元延迟元件耦合到第二 积分器，模拟（A / D）转换器和由A / D转换器的输出信号控制的1位数模转换器（D / A）转换器。 耦合到D / A转换器的输出的第一差分求和结点响应ΔΣ调制器输入信号。 耦合到第一差分求和结的输出的第二差分求和结还被耦合以从第二积分器接收反馈信号。 耦合到单元延迟元件的输出的第三差分求和结还接收来自第二积分器的前馈信号。

公开(公告)号：US6031874A

公开(公告)日：2000-02-29

申请号：US938516

申请日：1997-09-26

申请人： Sandeep Chennakeshu ,  Ravinder David Koilpillai

发明人： Sandeep Chennakeshu ,  Ravinder David Koilpillai

IPC分类号： H04L1/00 ,  H04L23/02

CPC分类号： H04L1/0058 ,  H04L1/0041 ,  H04L1/007

摘要： An important consideration in a coded modulation scheme is the choice of the component codes, which has a significant impact on the overall bit error rate performance and which determines the decoding complexity. Methods and apparatus employing product codes are described that can improve the performance of selected classes of information in the coded modulation scheme without affecting the decoding complexity or performance of other classes of information.

摘要翻译： 编码调制方案中的一个重要考虑因素是组件代码的选择，其对整体误码率性能具有显着影响，并且决定了解码的复杂性。 描述了使用产品代码的方法和装置，其可以改进编码调制方案中所选类别的信息的性能，而不影响其他类别的信息的解码复杂度或性能。

公开(公告)号：US5909465A

公开(公告)日：1999-06-01

申请号：US761003

申请日：1996-12-05

申请人： Gregory Edward Bottomley ,  Paul Wilkinson Dent ,  Ravinder David Koilpillai ,  Sandeep Chennakeshu

发明人： Gregory Edward Bottomley ,  Paul Wilkinson Dent ,  Ravinder David Koilpillai ,  Sandeep Chennakeshu

IPC分类号： H03M13/37 ,  H04B7/005 ,  H04B7/26 ,  H04L25/03 ,  H04L25/49 ,  H04Q1/20 ,  H04B17/00

CPC分类号： H04L25/03178 ,  H04L2025/0356

摘要： A system and method for bidirectionally demodulating data symbols transmitted through a communication channel. The method includes sequentially receiving and storing a first plurality of known data symbols, a second plurality of unknown data symbols, and a third plurality of known data symbols. Thereafter, a first block of the unknown data symbols received nearer the first plurality of known data symbols is forward-demodulated. Likewise, a second block of the unknown data symbols received nearer the third plurality of known data symbols is backward-demodulated. The forward- and backward-demodulation of the unknown data symbols determines quality values (figure-of-merits based on at least one of signal power, noise power and a combination of signal power plus noise power) indicative of demodulation qualities of the unknown data symbols that are compared to produce a best direction indication. Upon determining the best direction indication, either the forward- or backward-demodulation steps are repeated for subsequent blocks of unknown data symbols.

摘要翻译： 一种用于双向解调通过通信信道发送的数据符号的系统和方法。 该方法包括顺序地接收和存储第一多个已知数据符号，第二多个未知数据符号和第三多个已知数据符号。 此后，向第一多个已知数据符号接收的未知数据符号的第一块进行前向解调。 类似地，接收到的接近第三多个已知数据符号的未知数据符号的第二块被反向解调。 未知数据符号的前向和后向解调确定指示未知数据的解调质量的质量值（基于信号功率，噪声功率和信号功率加噪声功率的组合中的至少一个）的品质值 比较符号以产生最佳方向指示。 在确定最佳方向指示时，对于未知数据符号的后续块重复前向或后向解调步骤。

公开(公告)号：US5905742A

公开(公告)日：1999-05-18

申请号：US579349

申请日：1995-12-27

申请人： Sandeep Chennakeshu ,  Ravinder David Koilpillai ,  John B. Anderson

发明人： Sandeep Chennakeshu ,  Ravinder David Koilpillai ,  John B. Anderson

IPC分类号： H03M13/23 ,  H03M13/41 ,  H04L1/00 ,  H04L25/03 ,  G06F11/10

CPC分类号： H04L1/0071 ,  H03M13/41 ,  H03M13/6502 ,  H04L1/0009 ,  H04L25/03216

摘要： A low complexity, high performance trellis decoder adapts the complexity of the trellis decoding process based on a current condition of the communications system. A trellis structure of nodes and branches is developed to decode the sequence of symbols received over a communications channel. Each set of nodes in the trellis represents the possible values of a received symbol at one time instant. Each branch defines a specific transition between nodes at different time instants, and each branch has an associated branch metric or weight. A linkage of branches between the nodes and the trellis defines a path through the trellis that represents one possible symbol sequence, and an accumulated metric/weight is generated for each possible path through the trellis. A variable number M survivor paths through the trellis is determined based on their accumulated path metric/weights. The value of the variable M depends on the current condition of the communications system. Once the value of M is adapted to the current condition, the sequence of received symbols is decoded using M survivor paths through the trellis.

摘要翻译： 低复杂度的高性能网格解码器基于通信系统的当前状况来适应网格解码过程的复杂性。 开发节点和分支的网格结构来解码通过通信信道接收的符号序列。 网格中的每组节点在一个时刻表示接收到的符号的可能值。 每个分支定义不同时刻的节点之间的特定转换，并且每个分支具有关联的分支度量或权重。 节点和网格之间的分支的链接定义了通过网格的路径，其表示一个可能的符号序列，并且通过网格为每个可能的路径生成累积的度量/权重。 根据其累积的路径度量/权重来确定通过网格的可变数M个幸存者路径。 变量M的值取决于通信系统的当前状态。 一旦M的值适合于当前条件，则使用经过网格的M个幸存路径来解码接收符号的序列。

公开(公告)号：US5838739A

公开(公告)日：1998-11-17

申请号：US625010

申请日：1996-03-29

申请人： Rajaram Ramesh ,  Gregory E. Bottomley ,  Ravinder David Koilpillai ,  Ali S. Khayrallah

发明人： Rajaram Ramesh ,  Gregory E. Bottomley ,  Ravinder David Koilpillai ,  Ali S. Khayrallah

IPC分类号： H04L27/01 ,  H04B7/005 ,  H04L7/08 ,  H04L25/02 ,  H04L27/14 ,  H04B1/10

CPC分类号： H04L25/0212 ,  H04L7/042

摘要： Channel estimator circuitry and associated method for a digital receiver operates to estimate a channel impulse response of a transmission channel. When intersymbol interference is introduced upon a communication signal only by circuitry of a transmitter and a receiver, the quality of channel estimation is improved. Even when intersymbol interference is introduced upon a communication signal during its transmission, the quality of channel estimation is improved by decomposing the components of the intersymbol interference into portions introduced during transmission of the signal upon a communication channel and portions introduced by the transmitter and receiver circuitry.

摘要翻译： 用于数字接收机的信道估计器电路和相关联的方法用于估计传输信道的信道脉冲响应。 当通过发射机和接收机的电路在通信信号上引入符号间干扰时，提高了信道估计的质量。 即使当在其传输期间在通信信号上引入符号间干扰时，通过将符号间干扰的分量分解为在通信信道上传输信号期间引入的部分和由发射机和接收机电路引入的部分来改善信道估计的质量 。

公开(公告)号：US06678508B1

公开(公告)日：2004-01-13

申请号：US09499848

申请日：2000-02-07

申请人： Ravinder David Koilpillai ,  David R. Irvin

发明人： Ravinder David Koilpillai ,  David R. Irvin

IPC分类号： H04B1702

CPC分类号： H04B7/0871 ,  H04B7/0817 ,  H04B7/0857 ,  H04W52/0245 ,  Y02D70/444

摘要： A mobile communications device includes at least two receivers and a memory module. The power consumption of the mobile communications device is controlled by selectively awakening and sleeping the receivers as needed to ensure that the desired quality of reception to check the control channel for messages from an associated base station and to handle incoming communications is maintained. The mobile communications device may operate in single receiver mode or dual receiver diversity mode. In the dual receiver diversity mode, the mobile communications device may switch between one of a number of diversity combining techniques based on the quality of reception.

摘要翻译： 移动通信设备包括至少两个接收机和存储器模块。 通过根据需要有选择地唤醒和休眠接收机来控制移动通信设备的功耗，以确保维持从相关联的基站检查消息的控制信道的所需接收质量并处理进入的通信。 移动通信设备可以在单个接收机模式或双重接收机分集模式下操作。 在双重接收机分集模式中，移动通信设备可以基于接收质量在多个分集组合技术之一进行切换。

公开(公告)号：US06597743B1

公开(公告)日：2003-07-22

申请号：US09454577

申请日：1999-12-07

申请人： Ali S. Khayrallah ,  Gregory E. Bottomley ,  Ravinder David Koilpillai ,  Kambiz Zangi

发明人： Ali S. Khayrallah ,  Gregory E. Bottomley ,  Ravinder David Koilpillai ,  Kambiz Zangi

IPC分类号： H04L2302

CPC分类号： H03M13/3955

摘要： A reduced search symbol estimation algorithm includes a forward recursion, a backward recursion, and a combining step. To reduce complexity, during the forward and backward recursions, the number of survivor states retained at each stage is less than the total number of states of the trellis. The survivor states are selected from a group of candidate states, that are connected by branches to survivors from the previous stage of the recursion. The decoder compares the accumulated path metrics for each candidate state and retains a specified number of states that is less than the total possible number of states. For the forward recursion, the retained states or survivor states, denoted as Qk, are stored along with the corresponding state metrics. For the backward recursion, the retained states, denoted as Rk, are stored along with the corresponding state metrics. During the combining step, the computation of a soft value is restricted to branches (s′,s) connecting survivor states s′ and s in the forward and backward recursions respectively.

摘要翻译： 减少的搜索符号估计算法包括正向递归，反向递归和组合步骤。 为了减少复杂性，在向前和向后递归期间，每个阶段保留的幸存者国家数量小于网格状态总数。 幸存者状态是从一组候选国中选出的，这些候选国通过分支到递归的前一阶段与幸存者相连。 解码器比较每个候选状态的累积路径度量，并保留小于总可能状态数的指定数量的状态。 对于正向递归，保留状态或幸存者状态（表示为Qk）与相应的状态度量一起存储。 对于反向递归，表示为Rk的保留状态与相应的状态度量一起存储。 在组合步骤中，软值的计算分别限制在向前和向后递归中连接幸存者状态s'和s的分支（s'，s）。

公开(公告)号：US06327317B1

公开(公告)日：2001-12-04

申请号：US09393881

申请日：1999-09-10

申请人： Sandeep Chennakeshu ,  Ravinder David Koilpillai

发明人： Sandeep Chennakeshu ,  Ravinder David Koilpillai

IPC分类号： H03D100

CPC分类号： H04L1/0057 ,  H04L25/03019 ,  H04L25/03178 ,  H04L25/03184

摘要： Combined equalization and decoding of codewords in a coded modulation symbol sequence that has been received from a channel is accomplished in a number of ways. In an intersymbol interference (ISI) cancellation technique, channel impulse response (CIR) estimates corresponding to each received symbol of the coded modulation symbol sequence are determined. Codeword k of the received symbol sequence is then decoded using a maximum likelihood decoding trellis with a path metric that depends upon the CIR estimates and that includes at least one term representing intersymbol interference resulting from symbols of previously decoded codewords. The decoding step is repeated until all of the codewords of the received coded modulation symbol sequence have been decoded. In a maximum likelihood sequence estimation (MLSE)-based technique, an MLSE trellis is advanced from one stage to a next stage by updating a path metric having dependence on the CIR estimates and upon symbols of a codeword corresponding to a state in a previous trellis stage. The trellis-advancing step is repeated until all stages of the MLSE trellis are completed. Then, the codewords are decoded by using a traceback along the best path in the completed MLSE trellis. In another embodiment, a hybrid MLSE-ISI technique utilizes a path metric that depends upon the CIR estimates and upon symbols of a codeword corresponding to a state in a previous trellis stage. The path metric further includes at least one term that represents intersymbol interference resulting from symbols of previously decoded codewords.

摘要翻译： 已经以多种方式实现了从信道接收到的编码调制符号序列中码字的组合均衡和解码。 在符号间干扰（ISI）消除技术中，确定与编码调制符号序列的每个接收符号对应的信道脉冲响应（CIR）估计。 然后使用具有取决于CIR估计的路径度量的最大似然解码网格对接收到的符号序列的码字k进行解码，并且包括至少一个表示由先前解码的码字的符号产生的符号间干扰的项。 重复解码步骤，直到所接收的编码调制符号序列的所有码字已被解码。 在基于最大似然序列估计（MLSE）的技术中，通过更新具有对CIR估计的依赖性的路径度量以及对应于先前网格中的状态的码字的符号，MLSE网格从一个阶段进入下一个阶段 阶段。 重新进行网格推进步骤，直到MLSE网格的所有阶段完成。 然后，通过使用在完成的MLSE网格中的最佳路径的回溯来对码字进行解码。 在另一个实施例中，混合MLSE-ISI技术利用取决于CIR估计的路径度量，以及对应于先前网格级中的状态的码字的符号。 路径度量还包括至少一个术语，其表示由先前解码的码字的符号产生的符号间干扰。