公开(公告)号：US5263053A

公开(公告)日：1993-11-16

申请号：US856526

申请日：1992-03-24

申请人： Yongbing Wan ,  Qingli Liu ,  Andrew Sendyk

发明人： Yongbing Wan ,  Qingli Liu ,  Andrew Sendyk

IPC分类号： H04L25/03 ,  H04B15/00

CPC分类号： H04L25/03292

摘要： The channel-impulse-response estimator (44') in a maximum-likelihood-sequence-estimation receiver produces channel-model parameters for a model that produces outputs not only for symbol times but also for intermediate times between the symbol times. A symbol-sequence-derivation circuit (42') determines the most-likely sequence on the basis of metrics computed from the differences between the received signal and the responses of the model to candidate sequences not only at the symbol times but also at the intermediate times. An interpolator (100) receives the symbol decisions from the symbol-sequence-derivation circuit (42') and generates intermediate values from them by simulating the Nyquist filter formed by the concatenation of pulse-shaping filters (22 and 24) in the transmitter and matched filters (36 and 37) in the receiver. The channel-impulse-response estimator (44') uses these values together with the derived-symbol values as inputs to its updating process to maintain the model.

摘要翻译： 最大似然序列估计接收机中的信道脉冲响应估计器（44'）为不仅用于符号时间而且也用于符号时间之间的中间时间产生输出的模型产生信道模型参数。 符号序列导出电路（42'）基于从接收信号和模型与候选序列的响应之间的差异计算的度量来确定最可能的序列，不仅在符号时间，而且在中间 次 插值器（100）从符号序列导出电路（42'）接收符号判定，并通过模拟由发射机中的脉冲整形滤波器（22和24）的级联形成的奈奎斯特滤波器，从而产生中间值，并且 接收机中的匹配滤波器（36和37）。 信道脉冲响应估计器（44'）将这些值与导出的符号值一起用作其更新过程的输入以维持模型。

公开(公告)号：US5621769A

公开(公告)日：1997-04-15

申请号：US895542

申请日：1992-06-08

申请人： Yongbing Wan ,  Qingli Liu

发明人： Yongbing Wan ,  Qingli Liu

IPC分类号： H04B7/08 ,  H04L1/02 ,  H03D1/00

CPC分类号： H04B7/0851

摘要： A diversity receiver employing maximum-likelihood-sequence estimation employs a separate channel estimator (44-1, . . . , 44-L) for each of a plurality of diversity channels. Each channel estimator (44-1, . . . , 44-L) produces channel-model parameters ([f.sub.1 ], . . . , [f.sub.L ]) that characterize their respective channels. A weighting-and-accumulation circuit (56) computes the responses of the thus-represented models to candidate symbol sequences, and metrics indicating the likelihoods that respective candidate sequences were the sequences actually sent are determined by comparing the model output with the received signal in a comparison circuit (58) and squaring the magnitudes of the results in a squaring circuit (60). The receiver then employs a Viterbi algorithm (62) to determine which sequence is the one most likely to have been sent. In one version, it does this on the basis of the metrics calculated for the channel whose signal is strongest, while it determines the metrics by combining partial metrics from all of the channels in another version.

摘要翻译： 采用最大似然序列估计的分集接收机针对多个分集信道中的每一个使用单独的信道估计器（44-1，...，44-L）。 每个信道估计器（44-1，...，44-L）产生表征的信道模型参数（[+ E，cir f + EE 1]，...，[+ E，cir f + EE L] 各自的渠道。 加权和累积电路（56）计算由此表示的模型对候选符号序列的响应，并且通过将模型输出与接收到的信号进行比较来确定指示各个候选序列是实际发送的序列的可能性的度量 比较电路（58），并且将平均电路（60）中的结果的幅度平方。 然后，接收机采用维特比算法（62）来确定哪个序列是最可能被发送的序列。 在一个版本中，它基于为其信号最强的频道计算的指标，而通过组合另一版本中所有频道的部分指标来确定度量。

公开(公告)号：US5432803A

公开(公告)日：1995-07-11

申请号：US876324

申请日：1992-04-30

申请人： Qingli Liu ,  Xiangyang Chen ,  Lise Vanterpool ,  Andrew Sendyk

发明人： Qingli Liu ,  Xiangyang Chen ,  Lise Vanterpool ,  Andrew Sendyk

IPC分类号： H03M13/41 ,  G06F11/10

CPC分类号： H03M13/6505 ,  H03M13/3961 ,  H03M13/41 ,  H03M13/4107 ,  H03M13/4169

摘要： A maximum likelihood decoding system includes a branch metric processor which calculates only one of four branch metrics associated with branches leading to two consecutive states S.sub.j and S.sub.+1, where j is even. The system determines the remaining three metrics by producing a second branch metric by manipulating the first branch metric using simple binary operations and assigns the first and second metrics to the second and first branches, respectively, leading to the odd state. The system next retrieves associated path metrics from a path metric memory which stores the information in locations accessed by addresses related to identifiers associated with the branch initial states. After the system selects a surviving path for each end state, it stores in a path memory location associated with the end state information identifying the previous state on the surviving path. Thereafter, during trace back, the system uses the identifier of a known end state to address the path memory and retrieve the information identifying a previous state on the path. The system assigns data values to the branches of the most likely path as soon as it identifies the states on the path, since all branches leading to an even state are associated with a "ZERO" data bit and all branches leading to an odd state are associated with a "ONE" data bit.

摘要翻译： 最大似然解码系统包括分支度量处理器，其仅计算与分支导致两个连续状态Sj和S + 1相关联的四个分支度量中的一个，其中j是偶数。 该系统通过使用简单的二进制操作来操纵第一分支度量来产生第二分支度量来确定剩余的三个度量，并且分别将第一和第二度量分配给导致奇数状态的第二和第一分支。 系统接下来从路径度量存储器中检索相关联的路径度量，路径度量存储器将信息存储在通过与分支初始状态相关联的标识符相关的地址访问的位置中。 在系统为每个结束状态选择幸存路径之后，它存储在与存活路径上标识先前状态的结束状态信息相关联的路径存储器位置。 此后，在回溯期间，系统使用已知结束状态的标识符来寻址路径存储器并且检索标识路径上的先前状态的信息。 一旦识别路径上的状态，系统会将数据值分配给最可能路径的分支，因为导致均匀状态的所有分支都与“零”数据位相关联，导致奇数状态的所有分支都是 与“ONE”数据位相关联。

公开(公告)号：US06674795B1

公开(公告)日：2004-01-06

申请号：US09542212

申请日：2000-04-04

申请人： Qingli Liu ,  Aleksandar Purkovic

发明人： Qingli Liu ,  Aleksandar Purkovic

IPC分类号： H03H730

CPC分类号： H04L25/03038 ,  H03H21/0012 ,  H04L2025/03414 ,  H04L2025/03643

摘要： A system, device, and method for time-domain equalizer (TEQ) training determines the TEQ order and TEQ coefficients by applying the multichannel Levinson algorithm for auto-regressive moving average (ARMA) modeling of the channel impulse response. Specifically, the TEQ is trained based upon a received training signal. The received training signal and knowledge of the transmitted training signal are used to derive an autocorrelation matrix that is used in formulating the multichannel ARMA model. The parameters of the multichannel ARMA model are estimated via a recursive procedure using the multichannel Levinson algorithm. Starting from a sufficiently high-order model with a fixed pole-zero difference, the TEQ coefficients corresponding to a low-order model are derived from those of a high-order model.

摘要翻译： 用于时域均衡器（TEQ）训练的系统，设备和方法通过对通道脉冲响应的自回归移动平均（ARMA）建模应用多通道Levinson算法来确定TEQ顺序和TEQ系数。 具体地说，基于所接收的训练信号对TEQ进行训练。 所接收的训练信号和所传送的训练信号的知识被用于导出用于制定多声道ARMA模型的自相关矩阵。 通过使用多通道Levinson算法的递归过程来估计多通道ARMA模型的参数。 从具有固定极点零点的足够高阶模型开始，与低阶模型相对应的TEQ系数从高阶模型中导出。

公开(公告)号：US20120241685A1

公开(公告)日：2012-09-27

申请号：US13065282

申请日：2011-03-21

申请人： Kai Wu ,  Qingli Liu ,  Yali Yang ,  Steven Xiao

发明人： Kai Wu ,  Qingli Liu ,  Yali Yang ,  Steven Xiao

IPC分类号： H01B1/24 ,  C09D11/02

CPC分类号： C09D11/037 ,  C09D11/52

摘要： The invention provides a method for producing a PTC ink composition, which is capable of adjusting the switching temperature (Ts) of the PTC ink composition by addition of some additives. The content of the additive based on the total PTC composition for adjusting the Ts is less than 5.0 wt. %. The additives for adjusting the Ts can be chosen from polyester, polyether, and poly(ethylene glycol) with low molecular weight from 300 to 3000 g/mol.

摘要翻译： 本发明提供一种能够通过添加一些添加剂来调节PTC油墨组合物的切换温度（Ts）的PTC油墨组合物的制造方法。 基于用于调节Ts的总PTC组成的添加剂的含量小于5.0wt。 ％。 用于调节Ts的添加剂可以选自聚酯，聚醚和低分子量为300-3000g / mol的聚（乙二醇）。

公开(公告)号：US06819716B1

公开(公告)日：2004-11-16

申请号：US09542366

申请日：2000-04-04

申请人： Aleksander Purkovic ,  Qingli Liu

发明人： Aleksander Purkovic ,  Qingli Liu

IPC分类号： H04N712

CPC分类号： H04L25/03012 ,  H04L2025/03783 ,  H04N5/211

摘要： A system, device, and method for time-domain equalizer training injects noise into the received training signal prior to determining time-domain equalizer coefficients and determines the time-domain equalizer coefficients in the presence of the injected noise.

摘要翻译： 用于时域均衡器训练的系统，设备和方法在确定时域均衡器系数之前将噪声注入到接收到的训练信号中，并且在存在注入的噪声的情况下确定时域均衡器系数。

公开(公告)号：US5867538A

公开(公告)日：1999-02-02

申请号：US515175

申请日：1995-08-15

申请人： Qingli Liu

发明人： Qingli Liu

IPC分类号： H04L25/03 ,  H03D1/00

CPC分类号： H04L25/03171 ,  H04L2025/03401

摘要： The invention provides simple and reliable detection of .pi./4 shifted DQPSK modulated digital signals in a single-subscriber-unit, a multiple-subscriber unit (MSU) or a base transceiver station (BTS) of a fixed-wireless system, and is also directly applicable to other digital cellular or personal communication systems which utilizes a binary or M-ary PAM, FSK or PSK digital modulation scheme with differential or coherent encoding and time- and/or frequency-multiplexing. It offers great simplicity while providing soft-decision information for the later stage decoding of information bits encoded with an error correcting code. For each received sample z.sub.k+L and its estimated one z.sub.k+L, a Euclidean distance function is calculated. This Euclidean distance u(z.sub.k+L .vertline.v.sub.k+L, . . . , v.sub.k) is then added to the function derived from the previous iteration g(v.sub.k+L-1, . . . , v.sub.k), to yield a new Euclidean distance function f(v.sub.k+L, . . . , v.sub.k). Then a series of comparisons are carried out to find the minimum Euclidean distance with respect to each symbol within the channel memory span except v.sub.k. These minimum Euclidean distances are then added up to yield M values. The symbol corresponding to the minimum distance is the detected symbol. The same M Euclidean distance values are also used for soft decision derivation for use with an error detecting code. A simple measure of the accuracy of each symbol is calculated from the two shortest Euclidean distances. In particular, by taking the ratio of the difference to the sum of those two distances, the overall implementation of the demodulator becomes especially computationally efficient.

摘要翻译： 本发明提供在固定无线系统的单用户单元，多用户单元（MSU）或基站收发台（BTS）中的pi / 4移位DQPSK调制数字信号的简单和可靠的检测，并且还 直接适用于利用具有差分或相干编码以及时间和/或频率复用的二进制或M元PAM，FSK或PSK数字调制方案的其他数字蜂窝或个人通信系统。 它提供了极大的简单性，同时提供用于用纠错码编码的信息比特的后期解码的软判决信息。 对于每个接收的样本zk + L及其估计的一个+ E，cir z + EE k + L，计算欧氏距离函数。 然后，将这个欧几里得距离u（zk + L | vk + L，...，vk）加到从先前迭代g（vk + L-1，...，vk）得到的函数中，得到一个新的欧几里得 距离函数f（vk + L，...，vk）。 然后进行一系列比较，以找出除了vk之外的通道存储器跨度内的每个符号的最小欧几里德距离。 然后将这些最小欧几里德距离相加以产生M值。 对应于最小距离的符号是检测到的符号。 相同的M欧几里德距离值也用于软判决推导，用于检错码。 从两个最短的欧几里得距离计算每个符号的精度的简单度量。 特别地，通过将​​差值与这两个距离的总和相比较，解调器的总体实现变得特别计算效率。

公开(公告)号：US06754261B1

公开(公告)日：2004-06-22

申请号：US09542229

申请日：2000-04-04

申请人： Qingli Liu ,  Aleksandar Purkovic

发明人： Qingli Liu ,  Aleksandar Purkovic

IPC分类号： H03H730

CPC分类号： H04L27/2662 ,  H03H21/0032 ,  H04L2025/03414 ,  H04L2025/03477

摘要： A system, device, and method for determining the sampling time for a time-domain equalizer divides an over-sampled sequence into a plurality of individual Nyquist rate sequences, determines time-domain equalizer coefficients using one of the individual Nyquist rate sequences, and measures the performance for all individual Nyquist rate sequences using the time-domain equalizer coefficients. The Nyquist rate sequence having the best performance is selected, and the sampling time (delay) is configured so that the selected Nyquist rate sequence is provided to the time-domain equalizer.

摘要翻译： 用于确定时域均衡器的采样时间的系统，设备和方法将过采样序列划分为多个单独奈奎斯特速率序列，使用单个奈奎斯特速率序列之一来确定时域均衡器系数，并且测量 使用时域均衡器系数的所有单独奈奎斯特速率序列的性能。 选择具有最佳性能的奈奎斯特速率序列，并且配置采样时间（延迟），使得所选择的奈奎斯特速率序列被提供给时域均衡器。