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21. 发明授权

US6124898A Digital television receiver with equalization performed on digital intermediate-frequency signals 有权
标题翻译：数字电视接收机采用数字中频信号进行均衡
公开(公告)号：US6124898A
公开(公告)日：2000-09-26
申请号：US335516
申请日：1999-06-18
申请人： Chandrakant B. Patel , Allen LeRoy Limberg
发明人： Chandrakant B. Patel , Allen LeRoy Limberg
IPC分类号： H04N5/213 , H04N5/455
CPC分类号： H04L1/0065 , H04L25/03057 , H04L27/02 , H04N21/4382 , H04N5/211 , H04L2025/03356 , H04L2025/03382 , H04L2025/03503 , H04N5/455
摘要： A digital television signal receiver in a television set or in a digital video recorder digitizes received digital television signal as converted in frequency to a final intermediate-frequency band close to baseband, then performs equalization filtering on the digitized signal before demodulating it in the digital regime to regenerate baseband symbol coding. The equalization filtering is adaptive, and weighting coefficients for this filtering are adjusted in response to portions of the regenerated baseband symbol coding. Initial adjustment of the weighting coefficients is preferably done using selected portions of the data field synchronizing signal as a ghost cancellation reference signal, in order that convergence of the weighting coefficients to desired values proceeds more rapidly. Thereafter, adjustment of the weighting coefficients is preferably done using decision-directed methods that are continuously employed on all regenerated baseband symbols, better to track changing multipath conditions should they occur.
摘要翻译：电视机或数字视频录像机中的数字电视信号接收机将接收到的频率转换的数字电视信号数字化为接近基带的最终中频带，然后对数字信号进行均衡滤波，然后以数字方式对其进行解调以再生基带符号编码。均衡滤波是自适应的，并且响应于再生的基带符号编码的部分来调整用于该滤波的加权系数。加权系数的初始调整优选地使用数据场同步信号的选定部分作为重影消除参考信号进行，以便加权系数到期望值的收敛更快地进行。此后，优选地使用在所有再生的基带符号上连续采用的决策方法来进行加权系数的调整，更好地跟踪当它们发生变化的多径条件时。

22. 发明授权

US6118495A Training signal in plural PN sequences near beginnings of data segments of DTV signal or scan lines of NTSC signal 有权
标题翻译：在DTV信号或NTSC信号的扫描线的数据段的开始附近的多个PN序列中的训练信号
公开(公告)号：US6118495A
公开(公告)日：2000-09-12
申请号：US218015
申请日：1998-12-22
申请人： Allen LeRoy Limberg , Chandrakant B. Patel
发明人： Allen LeRoy Limberg , Chandrakant B. Patel
IPC分类号： H04L25/03 , H04N5/21 , H04N5/44 , H04N5/46 , H04N5/62 , H04N5/213
CPC分类号： H04L25/03006 , H04N5/211 , H04N5/4401 , H04N5/46 , H04N5/62 , H04L2025/03789 , Y10S348/914
摘要： Training signal for channel equalization is located in the initial data segment of each DTV data field and in the nineteenth scan line of each NTSC field. Arranging for training signal separated from plural PN sequences near the beginnings of the initial data segments of DTV data fields improves post-ghost detection capability in the DTV system. In receivers for receiving NTSC signals and DTV signals, arranging for training signal to be separated from plural PN sequences near the beginnings of the nineteenth scan line of each NTSC field facilitates the same ghost-cancellation and channel-equalization filtering being used both during the reception of NTSC signals and during the reception of DTV signals.
摘要翻译：用于信道均衡的训练信号位于每个DTV数据字段的初始数据段和每个NTSC字段的第十九扫描行中。在DTV数据字段的初始数据段开始附近的多个PN序列分离的训练信号的排列改善了DTV系统中的重影后检测能力。在用于接收NTSC信号和DTV信号的接收机中，排列要从每个NTSC场的第十九扫描线开始附近的多个PN序列分离的训练信号有助于在接收期间使用相同的重影消除和信道均衡滤波的NTSC信号和DTV信号的接收期间。

23. 发明授权

US5606579A Digital VSB detector with final IF carrier at submultiple of symbol rate, as for HDTV receiver 失效
标题翻译：数字VSB检测器与符号率相同的最终IF载波，如HDTV接收机
公开(公告)号：US5606579A
公开(公告)日：1997-02-25
申请号：US247753
申请日：1994-05-23
申请人： Chandrakant B. Patel , Allen L. Limberg
发明人： Chandrakant B. Patel , Allen L. Limberg
IPC分类号： H04N7/015 , H03D1/24 , H04L27/02 , H04N5/44 , H04N5/455
CPC分类号： H03D1/24 , H04L27/02 , H04N5/4401 , H04N5/455
摘要： In a radio receiver for receiving vestigial sideband (VSB) signals including symbol codes descriptive of digital signals, HDTV signals being exemplary of such VSB signals, a tuner provides for selecting one of channels at different locations in a frequency band used for transmitting such VSB signals. The tuner also includes mixers for performing plural conversion of the selected channel to a final intermediate-frequency (IF) signal, which is digitized by an analog-to-digital converter. The pilot carrier is detected by a narrowband quadrature-phase synchronous detector operative in the digital regime, for controlling the frequency and phase of the local oscillations applied to one of the mixers in the tuner so that the pilot carrier component of the final IF signal is locked to a submultiple of symbol frequency. The fullband final IF signal is synchronously detected by an in-phase synchronous detector to detect symbol codes. The departures of the actual symbol code levels from the ideal ones are detected by a symbol synchronizer and are used in generating corrections for the phasing of the sampling of the final IF signal when it is digitized by the analog-to-digital converter. The ideal symbol code levels in the fullband final IF signal are inferred from the amplitude of the pilot carrier as detected by a narrowband in-phase synchronous detector operative in the digital regime, for example.
摘要翻译：在用于接收包括描述数字信号的符号代码的残留边带（VSB）信号的无线电接收机中，HDTV信号是这样的VSB信号的示例，调谐器提供用于在用于发送这样的VSB信号的频带中的不同位置处选择一个信道。调谐器还包括用于执行所选频道的多个转换到由模数转换器数字化的最终中频（IF）信号的混频器。导频载波由在数字方式中操作的窄带正交相位同步检测器检测，用于控制施加到调谐器中的一个混频器的本地振荡的频率和相位，使得最终IF信号的导频载波分量为锁定到符号频率的多项。全频带最终IF信号由同相同步检波器同步检测，以检测符号码。实际符号代码电平与理想值的偏差由符号同步器检测，并用于在由模数转换器数字化时对最终IF信号的采样的相位进行相位调整。例如，通过在数字方式中操作的窄带同相同步检测器检测到的全频带最终IF信号中的理想符号码电平从导频载波的振幅推断出。

24. 发明授权

US5532755A Apparatus for suppressing ghosts in signals modulating a carrier in quadrature phasing with a video carrier 失效
标题翻译：用于抑制用视频载体正交相位调制载波的信号中的重影的装置
公开(公告)号：US5532755A
公开(公告)日：1996-07-02
申请号：US179616
申请日：1994-01-05
申请人： Chandrakant B. Patel , Jian Yang
发明人： Chandrakant B. Patel , Jian Yang
IPC分类号： H03H15/00 , H03H17/00 , H03H21/00 , H04B1/10 , H04B3/04 , H04L27/18 , H04N5/21 , H04N5/44
CPC分类号： H04N5/211
摘要： Composite video signal and a relatively low power phase-shift-keyed (PSK) signal encoding digital information are transmitted on respective phases of a video carrier in quadrature with each other. Selected scan lines of the composite video signal contain ghost-cancellation reference (GCR) signals. A digital signal receiver performs a first detection of the video carrier modulated in the two phases, down-converting to an intermediate-frequency (IF) signal. This IF signal is selectively amplified prior to respective second detection of the down-converted video carrier by in-phase and quadrature-phase synchronous video detectors. A first cascade filter connection of a first ghost-cancellation filter and a first equalization filter follows the in-phase video detector, and a second cascade filter connection of a second ghost-cancellation filter and a second equalization filter follows the quadrature-phase video detector. Gating circuitry selects scan lines containing GCR signals from the video signal response of the first cascade filter connection for accumulation, which generates separated ghosted GCR signal for use by a computer such as a microcomputer. Adjustable parameters of the ghost-cancellation filters are adjusted in parallel responsive to computer calculations, while adjustable parameters of the equalization filters are also adjusted in parallel responsive to further computer calculations. Iterative feedback reduces ghosts in the response of the first cascade filter connection. Ghosts in the response of the second cascade filter connection are reduced in an analogous manner.
摘要翻译：复合视频信号和相对较低功率的相移键控（PSK）信号编码数字信息在视频载波的各个相位上彼此正交地发送。复合视频信号的选定扫描线包含重影消除参考（GCR）信号。数字信号接收机对在两相调制的视频载波进行第一次检测，下变频到中频（IF）信号。在通过同相和正交相位同步视频检测器对下变频视频载波进行相应的第二次检测之前，该IF信号被选择性地放大。第一重影消除滤波器和第一均衡滤波器的第一级联滤波器连接跟随在同相视频检测器中，并且第二重影消除滤波器和第二均衡滤波器的第二级联滤波器连接遵循正交相位视频检测器。选通电路从第一级联滤波器连接的视频信号响应中选择包含GCR信号的扫描线进行累积，产生分离的重影GCR信号，供微计算机等计算机使用。响应于计算机计算，并行地调整重影消除滤波器的可调参数，同时响应于进一步的计算机计算，均衡滤波器的可调参数也被并行调整。迭代反馈减少了第一级联滤波器连接响应中的重影。以类似的方式减少第二级联滤波器连接的响应中的幽灵。

25. 发明授权

US5479449A Digital VSB detector with bandpass phase tracker, as for inclusion in an HDTV receiver. 失效
标题翻译：带有带通相位跟踪器的数字VSB检测器，用于包含在HDTV接收机中。
公开(公告)号：US5479449A
公开(公告)日：1995-12-26
申请号：US237896
申请日：1994-05-04
申请人： Chandrakant B. Patel , Allen L. Limberg
发明人： Chandrakant B. Patel , Allen L. Limberg
IPC分类号： H04B1/16 , H04L27/02 , H04L27/06 , H04N5/52 , H04N7/015 , H04N21/2383 , H04N21/438
CPC分类号： H04N21/2383 , H04L27/02 , H04N21/4382
摘要： In a radio receiver for receiving vestigial sideband (VSB) signals including symbol codes descriptive of digital signals, HDTV signals being exemplary of such VSB signals, a tuner provides for selecting one of channels at different locations in a frequency band used for transmitting such VSB signals. The tuner also includes mixers for performing plural conversion of the selected channel to a final intermediate-frequency signal, which is digitized by an analog-to-digital converter. A phase tracker, operative on narrow-bandpass filtered portions of the digitized final intermediate-frequency signal centering on its carrier frequency, suppresses an imaginary portion of the final intermediate-frequency signal, arising from multipath distortion or from phase incoherency in local oscillations used during frequency conversion. A digital controlled oscillator in the phase tracker supplies digital descriptions of the carrier wave for the final intermediate-frequency signal to a synchronous detector, which synchronous detector detects the real portion of the digitized final intermediate-frequency signal in accordance with those digital descriptions of the carrier wave.
摘要翻译：在用于接收包括描述数字信号的符号代码的残留边带（VSB）信号的无线电接收机中，HDTV信号是这样的VSB信号的示例，调谐器提供用于在用于发送这样的VSB信号的频带中的不同位置处选择一个信道。调谐器还包括用于执行所选频道的多个转换到由模数转换器数字化的最终中频信号的混频器。基于其载波频率的数字化的最终中频信号的窄带通滤波部分的相位跟踪器抑制由多径失真引起的最终中频信号的虚部，或从多径失真引起的本地振荡中的相位不相干性变频。相位跟踪器中的数字控制振荡器将最终中频信号的载波的数字描述提供给同步检波器，该同步检测器根据这些数字描述的数字化最终中频信号的实际部分载波。

26. 发明授权

US5361102A System to cancel ghosts in NTSC television transmission 失效
标题翻译：在NTSC电视传输中取消重影的系统
公开(公告)号：US5361102A
公开(公告)日：1994-11-01
申请号：US754895
申请日：1991-09-04
申请人： Sumit Roy , Chandrakant B. Patel , Jian Yang
发明人： Sumit Roy , Chandrakant B. Patel , Jian Yang
IPC分类号： H04N5/21 , H04N5/213
CPC分类号： H04N5/211
摘要： A new technique for channel characterization for Advanced Compatible TV (ACTV) broadcasting systems is hereby proposed that conforms to the current practice of transmitting a ghost cancellation reference (GCR) signal during the vertical blanking interval (VBI). A copy of the GCR signal is stored at the receiver, and is used to extract the effective ghost channel parameters via digital signal processing techniques. A pair of equi-length, binary (.+-.) sequences is said to be complementary if the sum of the linear autocorrelation functions of the sequences is identically zero for all shifts other than zero, and provides a high correlation gain at zero shift. Such sequences can be sequentially transmitted on the allotted VBI line in the appropriate fields, along with pairwise constant signals in the corresponding fields of a basic eighth field sequence. To conform to the positivity constraint of the transmitted signal for NTSC compatible systems, each complementary sequence is transmitted on a pedestal. At the receiver, the effect of the common constant signals are first removed by subtraction and the resultant signals are correlated with each of the two complementary sequences. The output of the correlators are added to directly yield estimates of the channel coefficients.
摘要翻译：因此，提出了符合在垂直消隐间隔（VBI）期间发送重影消除参考（GCR）信号的当前实践的用于高级兼容电视（ACTV）广播系统的信道表征的新技术。 GCR信号的副本存储在接收器处，并用于通过数字信号处理技术提取有效的重影信道参数。如果对于除零之外的所有移位，序列的线性自相关函数之和相同为零，则称为一对等长二进制（+/-）序列，并在零漂移时提供高相关增益。这样的序列可以在适当的场中的分配的VBI线上连续发送，以及基本第八场序列的相应字段中的成对恒定信号。为了符合NTSC兼容系统的发送信号的积极约束，每个互补序列在基座上传输。在接收机处，首先通过减法去除公共常数信号的影响，并将所得到的信号与两个互补序列中的每一个相关联。添加相关器的输出以直接产生信道系数的估计。

27. 发明授权

US4686560A Phase locked loop system including analog and digital components 失效
标题翻译：锁相环系统包括模拟和数字组件
公开(公告)号：US4686560A
公开(公告)日：1987-08-11
申请号：US868567
申请日：1986-05-30
申请人： Alvin R. Balaban , Chandrakant B. Patel , Walter H. Demmer , Leopold A. Harwood
发明人： Alvin R. Balaban , Chandrakant B. Patel , Walter H. Demmer , Leopold A. Harwood
IPC分类号： H03L7/06 , H03L7/087 , H04L5/06 , H04N9/45 , H04N9/66
CPC分类号： H04N9/45 , H03L7/087
摘要： A digital television receiver, having a line-locked clock, includes a partly digital, partly analog phase locked loop. This phase locked loop regenerates two quadrature phase related subcarrier signals that are used to synchronously demodulate the chrominance signal components of the composite video signals into two color informaiton signals. The phase locked loop includes an analog voltage controlled oscillator which generates a signal that is independent of any frequency instability in the line locked clock signal. An analog-to-digital converter digitizes this signal to provide one of the subcarrier signals. This subcarrier signal is applied to a read-only memory to generate the second subcarrier signal. The two color information signals are obtained by multiplying the chrominance signals by the first and second subcarrier signals. A phase comparator determines the phase of the vector sum of the two color information signals and compares this against a desired phase value to generate a phase difference signal. The phase difference signal is filtered and applied to a digital-to-analog converter which provides the frequency control signal for the analog voltage controlled oscillator. In a second embodiment of the invention, a tracking filter is inserted at the output port of the analog-to-digital converter to allow the quantization resolution of the analog-to-digital to be reduced without affecting the performance of the phase locked loop.
摘要翻译：具有线锁时钟的数字电视接收机包括部分数字部分模拟锁相环。该锁相环再生两个相位相关的副载波信号，用于将复合视频信号的色度信号分量同步解调成两个彩色信号信号。锁相环包括模拟压控振荡器，其产生独立于线路锁定时钟信号中的任何频率不稳定性的信号。模数转换器对该信号进行数字化以提供副载波信号之一。该子载波信号被施加到只读存储器以产生第二副载波信号。通过将色度信号乘以第一和第二子载波信号来获得两个颜色信息信号。相位比较器确定两个颜色信息信号的矢量和的相位，并将其与期望的相位值进行比较以产生相位差信号。相位差信号被滤波并施加到数模转换器，该转换器为模拟压控振荡器提供频率控制信号。在本发明的第二实施例中，跟踪滤波器被插入在模数转换器的输出端口，以允许在不影响锁相环的性能的情况下降低模拟数字的量化分辨率。

28. 发明授权

US4663653A Vertical detail enhancer 失效
标题翻译：垂直细节增强剂
公开(公告)号：US4663653A
公开(公告)日：1987-05-05
申请号：US800823
申请日：1985-11-22
申请人： Chandrakant B. Patel
发明人： Chandrakant B. Patel
IPC分类号： H04N5/208 , H04N7/01 , H04N9/64 , H04N9/68 , H04N9/77 , H04N11/20
CPC分类号： H04N9/646
摘要： A vertical detail enhancer for use in a progressive scan video signal processor is disclosed. An interstitial luminance signal producer produces interstitial luminance signals in response to interlaced luminance signals from a source of such signals. Means modify the interlaced and interstitial luminance signals for enhancing the vertical detail of the displayed image by adding only overshoot to leading edges and only undershoot to trailing edges. Further means sequence the vertical detail enhanced interlaced and interstitial luminance signals to produce a signal representing a progressively scanned image.
摘要翻译：公开了一种用于逐行扫描视频信号处理器的垂直细节增强器。间隙亮度信号生成器响应于来自这种信号的源的隔行亮度信号产生间隙亮度信号。意味着修改隔行扫描和间隙亮度信号，以通过仅向前沿添加过冲，并且仅下冲到后沿来增强所显示图像的垂直细节。进一步意味着排列垂直细节增强隔行和间隙亮度信号以产生表示逐渐扫描图像的信号。

29. 发明授权

US4594610A Camera zoom compensator for television stereo audio 失效
标题翻译：电视立体声音频相机变焦补偿器
公开(公告)号：US4594610A
公开(公告)日：1986-06-10
申请号：US660967
申请日：1984-10-15
申请人： Chandrakant B. Patel
发明人： Chandrakant B. Patel
IPC分类号： H04N5/60 , H04N7/04
CPC分类号： H04N5/607
摘要： A stereophonic television signal processing arrangement includes a television camera having a zoom lens capable of wide and narrow viewing angles. A sensor coupled to the zoom lens generates a control signal indicative of the current field of view. An audio signal generator such as a pair of microphones and a matrix generates L+R and L-R audio signals. In order to ameliorate a perception problem associated with expectations as to the direction (left or right) from which the audio signal comes when viewing a receiver showing a narrow-field-of-view picture, a multiplier arrangement multiplies the L+R and L-R signals by factors K.sub.1 and K.sub.2, respectively, which are directly and inversely related, respectively, to the control signal indicative of current field of view.
摘要翻译：立体声电视信号处理装置包括具有能够宽和窄视角的变焦透镜的电视摄像机。耦合到变焦透镜的传感器产生指示当前视场的控制信号。诸如一对麦克风和矩阵之类的音频信号发生器产生L + R和L-R音频信号。为了改善与观看显示窄视场图像的接收机的音频信号到达的方向（左或右）相关的感知问题，乘法器布置将L + R和LR 分别与因子K1和K2分别与指示当前视场的控制信号直接和相反地相关的信号。

30. 发明授权

US06545728B1 Digital television receivers that digitize final I-F signals resulting from triple-conversion 失效
标题翻译：数字电视接收机，将三重转换产生的最终I-F信号数字化
公开(公告)号：US06545728B1
公开(公告)日：2003-04-08
申请号：US09294304
申请日：1999-04-14
申请人： Chandrakant B. Patel , Allen LeRoy Limberg
发明人： Chandrakant B. Patel , Allen LeRoy Limberg
IPC分类号： H04N544
CPC分类号： H04N5/4446 , H03D1/24 , H03D5/00 , H04B1/28 , H04L1/0054 , H04L1/006 , H04L27/02 , H04N5/4401 , H04N5/455 , H04N5/46
摘要： Receiving apparatus for digital television signals digitizes a final intermediate frequency signal supplied from a triple-conversion radio receiver and synchrodynes the digitized final intermediate frequency signal to baseband. The triple-conversion radio receiver selects one of a plurality of digital television signals for upconversion to that portion of the electromagnetic frequency spectrum above the channels that are used for television broadcasting, amplifies a first intermediate-frequency signal in a first intermediate frequency band generated by that upconversion, amplifies a second intermediate-frequency signal in a second intermediate frequency band generated by downconverting the amplified first intermediate-frequency signal, and supplies a third intermediate-frequency signal in a third intermediate frequency band generated by downconverting the amplified second intermediate-frequency signal. This third intermediate-frequency signal is the final intermediate-frequency signal supplied to the analog-to-digital converter for being linearly converted to a digitized third intermediate-frequency signal. Digital synchrodyning circuitry synchrodynes the digitized third intermediate-frequency signal to baseband and thereby generates at least a real component of digital baseband signal. Circuitry responsive to at least the real component of the digital baseband signal recovers a stream of digital data descriptive of the video and audio portions of television programming.
摘要翻译：用于数字电视信号的接收装置对从三重转换无线电接收机提供的最终中频信号进行数字化，并将数字化的最终中频信号同步到基带。三重转换无线电接收机选择多个数字电视信号中的一个用于上变频到用于电视广播的信道上方的电磁频谱的那部分，放大由第一中频频带产生的第一中频频带通过下变频放大的第一中频信号产生的第二中频带放大第二中频信号，并将第三中频信号提供在通过下变频放大的第二中频信号产生的第三中频带信号。该第三中频信号是提供给模数转换器的最终中频信号，用于线性转换为数字化的第三中频信号。数字同步电路将数字化的第三中频信号同步到基带，从而产生数字基带信号的至少一个实部分量。响应于至少数字基带信号的实际分量的电路恢复描述电视节目的视频和音频部分的数字数据流。

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