专利快速检索-快速检索全球专利，免费商用专利数据库-IPRDB

1. 发明授权

US4694327A Digital phase locked loop stabilization circuitry using a secondary digital phase locked loop 失效
标题翻译：数字锁相环路稳定电路采用次级数字锁相环
公开(公告)号：US4694327A
公开(公告)日：1987-09-15
申请号：US845850
申请日：1986-03-28
申请人： Walter H. Demmer , Leopold A. Harwood , Chandrakant B. Patel , Alvin R. Balaban
发明人： Walter H. Demmer , Leopold A. Harwood , Chandrakant B. Patel , Alvin R. Balaban
IPC分类号： H03L7/06 , H03L7/087 , H03L7/099 , H03L7/22 , H04N9/45
CPC分类号： H04N9/45 , H03L7/0994 , H03L7/22
摘要： A digital television receiver includes a first phase locked loop which develops a sampling clock signal that is locked to the horizontal line synchronizing signal components of a composite video signal. A second digital phase locked loop is clocked by the sampling clock signal and develops a digital signal that is phase locked to the color burst signal. This digital signal is used as a regenerated color subcarrier signal to synchronously demodulate the chrominance components of the composite video signals into I and Q color difference signals. To compensate for frequency instability in the regenerated subcarrier signal caused by frequency instabilities in the line-locked clock signal, a third digital phase locked loop develops an output signal which is phase locked to a reference signal generated by a crystal controlled oscillator. Control signals from the third phase locked loop are applied to the second phase locked loop to substantially compensate for frequency instabilities in the regenerated subcarrier signal that are induced by the clock signals.
摘要翻译：数字电视接收机包括第一锁相环，其产生锁定到复合视频信号的水平线同步信号分量的采样时钟信号。第二数字锁相环由采样时钟信号计时，并产生与色同步信号锁相的数字信号。该数字信号用作再生彩色副载波信号，以将复合视频信号的色度分量同步解调为I和Q色差信号。为了补偿由线锁定时钟信号中的频率不稳定性引起的再生子载波信号中的频率不稳定性，第三数字锁相环产生锁相到由晶体振荡器产生的参考信号的输出信号。来自第三锁相环的控制信号被施加到第二锁相环，以基本上补偿由时钟信号引起的再生子载波信号中的频率不稳定性。

2. 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。

3. 发明授权

US4703340A Frequency division multiplexed analog to digital converter 失效
标题翻译：频分复用模数转换器
公开(公告)号：US4703340A
公开(公告)日：1987-10-27
申请号：US858720
申请日：1986-05-02
申请人： Alvin R. Balaban , Leopold A. Harwood , Chandrakant B. Patel , Walter H. Demmer
发明人： Alvin R. Balaban , Leopold A. Harwood , Chandrakant B. Patel , Walter H. Demmer
IPC分类号： H04N5/14 , H04N9/64 , H04N11/04 , H04N5/00
CPC分类号： H04N9/64
摘要： A digital television receiver, having a line locked clock, includes a first digital phase locked loop which regenerates quadrature phase related subcarrier signals that are used to synchronously demodulate the chrominance signal components of composite video signals into color information signals. When nonstandard video signals (e.g., from a video tape recorder) are processed by the receiver, frequency instabilities in the line locked clock signal may cause the color information signals to be distorted. To compensate for this distortion, a second phase locked loop is synchronized to a reference signal generated by an analog oscillator. The analog reference signal is linearly added to baseband analog video signals provided by a tuner. The combined signals are digitized by an analog-to-digital converter and then filtered by parallel low-pass and band-pass filters to develop digital signals representing the video signals and the reference signal, respectively. The digital reference signal is used to synchronize the second phase locked loop, the control signals of which are used to compensate the first phase locked loop for frequency instabilities in the clock signal.
摘要翻译：具有线锁定时钟的数字电视接收机包括第一数字锁相环，其再生用于将复合视频信号的色度信号分量同步解调为彩色信息信号的正交相位相关副载波信号。当非标准视频信号（例如，来自录像机）由接收机处理时，线路锁定时钟信号中的频率不稳定性可能导致颜色信息信号失真。为了补偿这种失真，第二个锁相环与由模拟振荡器产生的参考信号同步。模拟参考信号线性地添加到由调谐器提供的基带模拟视频信号。组合的信号由模拟数字转换器数字化，然后通过并行低通和带通滤波器进行滤波，以分别开发表示视频信号和参考信号的数字信号。数字参考信号用于同步第二锁相环，其控制信号用于补偿第一锁相环中的时钟信号中的频率不稳定性。

4. 发明授权

US4700217A Chrominance signal phase locked loop system for use in a digital television receiver having a line-locked clock signal 失效
标题翻译：色度信号锁相环系统，用于具有线锁时钟信号的数字电视接收机
公开(公告)号：US4700217A
公开(公告)日：1987-10-13
申请号：US893185
申请日：1986-08-05
申请人： Alvin R. Balaban , Walter H. Demmer , Leopold A. Harwood , Chandrakant B. Patel
发明人： Alvin R. Balaban , Walter H. Demmer , Leopold A. Harwood , Chandrakant B. Patel
IPC分类号： H04N9/45 , H04N9/66
CPC分类号： H04N9/45 , H04N9/66
摘要： A digital television receiver which uses a line-locked clock signal employs chrominance signal demodulation circuitry which produces a digital oscillatory signal that is locked in phase to the color reference burst signal component of the incoming video signals. An analog voltage controlled oscillator generates an oscillatory signal having a frequency of approximately twice the color subcarrier frequency. This signal is combined with the composite video signals and the combined signal is digitized by an analog to digital converter. The digitized oscillatory signal is separated from the combined digital signal and is used to synchronize a digital phase locked loop. The digital phase locked loop generates two quadrature phase related signals having frequencies that are one-half the frequency of the analog oscillatory signal. These two signals are used to synchronously demodulate the chrominance signal components of the incoming video signals to obtain two quadrature phase related color difference signals. The control signal for the voltage controlled oscillator is generated by subtracting the burst phase of the demodulated color difference signals from a reference phase and integrating the difference.
摘要翻译：使用线锁时钟信号的数字电视接收机采用色度信号解调电路，其生成与输入视频信号的颜色参考突发信号分量锁相的数字振荡信号。模拟压控振荡器产生具有大约是彩色副载波频率的两倍的频率的振荡信号。该信号与复合视频信号组合，组合信号由模数转换器数字化。数字振荡信号与组合数字信号分离，用于同步数字锁相环。数字锁相环产生频率为模拟振荡信号频率的一半的两个正交相位相关信号。这两个信号用于同步解调输入视频信号的色度信号分量，以获得两个正交相位相关的色差信号。压控振荡器的控制信号通过从参考相位减去解调色差信号的脉冲串相位而积分该差而产生。

5. 发明授权

US4651196A Adaptive control of the chrominance signal frequency response in a video signal processing system 失效
标题翻译：视频信号处理系统中色度信号频率响应的自适应控制
公开(公告)号：US4651196A
公开(公告)日：1987-03-17
申请号：US713753
申请日：1985-03-19
申请人： Leopold A. Harwood , Chandrakant B. Patel
发明人： Leopold A. Harwood , Chandrakant B. Patel
IPC分类号： H04N9/64 , H04N9/77
CPC分类号： H04N9/646
摘要： A digital television receiver, which uses a comb filter to separate the luminance and chrominance components of composite video signals, includes an adaptive band-pass filter for processing the comb filtered chrominance signals. Comb filtered chrominance signals may include luminance vertical detail information at the relatively high frequencies also occupied by chrominance information. The adaptive band-pass filter is controlled to have a narrow bandwidth when significant amounts of this relatively high frequency vertical detail information are present and to have a wide bandwidth otherwise. Consequently, the bandwidth of the chrominance signal provided by this filter is restricted only when it is necessary to prevent distortion, and vertical detail is added to the luminance signal only when it is not likely to be contaminated with chrominance information.
摘要翻译：使用梳状滤波器分离复合视频信号的亮度和色度分量的数字电视接收机包括用于处理梳状滤波色度信号的自适应带通滤波器。梳状滤波的色度信号可以包括也被色度信息占据的相对高的频率的亮度垂直细节信息。当存在大量这种相对高频率的垂直细节信息并且否则具有宽带宽时，自适应带通滤波器被控制为具有窄带宽。因此，仅当需要防止失真时才限制由该滤波器提供的色度信号的带宽，并且仅当不可能被色度信息污染时才将亮度信号添加到亮度信号。

6. 发明授权

US4686561A Vertical detail information restoration circuit 失效
标题翻译：垂直细节信息恢复电路
公开(公告)号：US4686561A
公开(公告)日：1987-08-11
申请号：US760910
申请日：1985-07-31
申请人： Leopold A. Harwood , Robert A. Wargo , Chandrakant B. Patel
发明人： Leopold A. Harwood , Robert A. Wargo , Chandrakant B. Patel
IPC分类号： H04N9/78 , H04N5/208 , H04N9/64 , H04N9/77 , H04N5/21
CPC分类号： H04N9/646
摘要： In a composite color video signal, a portion of the signal spectrum is shared by high frequency vertical detail information, and high frequency modulated color difference (I) information. A circuit is described which determines whether the information in the shared frequency band is vertical detail information or color difference information without degradation in the presence of a step input signal, as, for example, in the presence of lettering in the image. A composite video signal is comb filtered to generate comb filtered chrominance and luminance signals. A baseband color difference signal is produced from the comb filtered chrominance signal and the presence of high frequency information in the baseband color difference signal is detected. The bandwidth of the low frequency portion of the comb filtered chrominance signal (i.e. the vertical detail information) which is restored to the comb filtered luminance signal is varied in response to the control signal.
摘要翻译：在复合彩色视频信号中，信号频谱的一部分由高频垂直细节信息和高频调制色差（I）信息共享。描述了一种电路，其确定在共享频带中的信息是垂直细节信息还是色差信息，而不存在步进输入信号的劣化，例如在图像中存在刻字。梳状滤波复合视频信号以产生梳状滤波色度和亮度信号。从梳状滤波色度信号产生基带色差信号，并检测基带色差信号中是否存在高频信息。梳状滤波色度信号的低频部分的带宽（即垂直细节信息）被恢复到梳状滤波的亮度信号，响应于控制信号而变化。

7. 再颁专利

USRE38456E1 Decimation of baseband DTV signals prior to channel equalization in digital television signal receivers 失效
标题翻译：在数字电视信号接收机的信道均衡之前抽取基带DTV信号
公开(公告)号：USRE38456E1
公开(公告)日：2004-03-09
申请号：US09973825
申请日：2001-10-11
申请人： Chandrakant B. Patel , Allen LeRoy Limberg
发明人： Chandrakant B. Patel , Allen LeRoy Limberg
IPC分类号： H04N5455
CPC分类号： H04N5/4446 , H03D1/24 , H03D5/00 , H04B1/28 , H04L1/0054 , H04L1/0071 , H04N5/4401 , H04N5/455
摘要： A radio receiver uses the same tuner for receiving a selected digital television (DTV) signal, irrespective of whether it is a quadrature-amplitude-modulation (QAM) or a vestigial sideband (VSB) signal. The final IF signal is digitized at a rate that is a multiple of both the symbol frequencies of the QAM and VSB signals, for synchrodyning to baseband. The carrier frequencies of the QAM and VSB final IF signals are regulated to be submultiples of the multiple of both the symbol frequencies of the QAM and VSB signals by applying automatic frequency and phase control (AFPC) signals developed in the digital circuitry to a local oscillator of the tuner. Baseband DTV signals obtained by synchrodyning the final IF signals have a sample rate higher than symbol rate to facilitate symbol synchronization. The baseband DTV signals are decimated to symbol rate before performing channel equalization to reduce the number of multipliers required in the channel equalization filter.

8. 发明授权

US06535553B1 Passband equalizers with filter coefficients calculated from modulated carrier signals 有权
标题翻译：通过调制载波信号计算滤波器系数的通带均衡器
公开(公告)号：US06535553B1
公开(公告)日：2003-03-18
申请号：US09335514
申请日：1999-06-18
申请人： Allen LeRoy Limberg , Chandrakant B. Patel
发明人： Allen LeRoy Limberg , Chandrakant B. Patel
IPC分类号： H03H730
CPC分类号： H04L27/01
摘要： A digital communications radio receiver, as for television, digitizes a final intermediate-frequency signal offset from zero frequency no more than a few megahertz. This digitized final I-F signal is passed through an adaptive equalizer before being synchrodyned to baseband in the digital regime, which adaptive equalizer has its weighting coefficients determined by comparing I-F signal as received with possible multipath with ideal I-F signal free from multipath distortion. Decision feedback for adjusting the filtering coefficients of the equalizer is described, which is based on the ideal baseband signal being re-modulated onto final I-F carrier and compared to the received signal as translated in frequency to provide the final I-F signal. A training-signal method for adjusting the filtering coefficients of the equalizer is described, which characterizes the reception channel by comparing prescribed portions of the received signal as translated in frequency to provide the final I-F signal to final I-F signal segments stored at the receiver. Equalization of the final I-F signal based on error signals derived from modulated I-F signal, rather than from demodulated baseband signal, allows different equalization of the upper sideband and the lower sideband of the final I-F signal. This facilitates receiver passband tilts as well as multipath distortion being compensated for.
摘要翻译：数字通信无线电接收机，对于电视机，将最终的中频信号偏移从零频率数字化，不超过几兆赫兹。该数字化的最终I-F信号在与数字方式中的基带同步到基带之前通过自适应均衡器，该自适应均衡器通过将接收到的I-F信号与可能的多路径与没有多径失真的理想I-F信号进行比较来确定其加权系数。描述了用于调整均衡器的滤波系数的判决反馈，其基于将理想基带信号重新调制到最终的I-F载波上并与接收的信号进行频率比较，以提供最终的I-F信号。描述了用于调整均衡器的滤波系数的训练信号方法，其通过比较频率转换的接收信号的规定部分来表征接收信道，以将最终I-F信号提供给存储在接收机处的最终I-F信号段。基于从调制的I-F信号而不是从解调的基带信号导出的误差信号的最终I-F信号的均衡允许最终I-F信号的上边带和下边带的不同均衡。这有助于接收机通带倾斜以及补偿的多径失真。

9. 发明授权

US06313885B1 DTV receiver with baseband equalization filters for QAM signal and for VSB signal which employ common elements 有权
标题翻译：具有用于QAM信号的基带均衡滤波器和采用公共元件的VSB信号的DTV接收机
公开(公告)号：US06313885B1
公开(公告)日：2001-11-06
申请号：US09440132
申请日：1999-11-15
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： H04N21/4383 , H04L1/0045 , H04L27/0008 , H04N5/211 , H04N5/4401 , H04N5/4446 , H04N5/445 , H04N5/455 , H04N5/46
摘要： During the reception of VSB DTV signal, the channel equalizer for a QAM/VSB DTV signal receiver the equalizer is operated to equalize only the real sample stream of VSB symbol code, rather than being operated as a complex equalizer. During the reception of QAM DTV signal, the real sample stream of QAM symbol code and the imaginary sample stream of QAM symbol code are time-division-multiplexed together on an alternate sample basis to generate input signal for the channel equalizer, which is operated as a dual-phase filter. After equalization, the time-division-multiplexed real and imaginary samples of QAM symbol code are de-multiplexed to recover parallel real and imaginary sample streams of QAM symbol code that are independent of each other, but have been subjected to similar equalization. Supposing that the QAM DTV symbol code rate is half the VSB DTV symbol code rate, the minimum sampling rate for operation of the channel equalizer is the same for both types of symbol code.
摘要翻译：在接收VSB DTV信号期间，对于QAM / VSB DTV信号接收机的信道均衡器，均衡器被操作以均衡VSB符号码的实际样本流，而不是作为复均衡器来操作。在QAM DTV信号的接收期间，QAM符号码的实际采样流和QAM符号码的虚数采样流在交替采样的基础上被一起进行时分复用，以生成用于信道均衡器的输入信号，该输入信号作为一个双相滤波器。在均衡之后，将QAM符号码的时分多路复用实数和样本解复用，以恢复彼此独立但已进行类似均衡的QAM符号码的并行实数和虚数采样流。假设QAM DTV符号码率是VSB DTV符号码率的一半，则对于两种类型的符号码，信道均衡器的操作的最小采样率是相同的。

10. 发明授权

US6134373A System for recording and reproducing a wide bandwidth video signal via a narrow bandwidth medium 失效
标题翻译：用于通过窄带宽媒体记录和再现宽带宽视频信号的系统
公开(公告)号：US6134373A
公开(公告)日：2000-10-17
申请号：US787690
申请日：1991-11-04
申请人： Christopher H. Strolle , Chandrakant B. Patel , Werner F. Wedam , Jung Wan Ko , Raymond Schnitzler , Jong Kyung Yun
发明人： Christopher H. Strolle , Chandrakant B. Patel , Werner F. Wedam , Jung Wan Ko , Raymond Schnitzler , Jong Kyung Yun
IPC分类号： H04N5/93 , H04N9/78 , H04N9/797 , H04N9/80 , H04N9/82 , H04N9/83 , H04N9/835 , H04N9/84 , H04N9/898 , H04N9/79
CPC分类号： H04N9/831 , H04N9/797 , H04N9/7976 , H04N9/80 , H04N9/8205 , H04N9/835 , H04N9/84 , H04N9/898
摘要： An encoder separates luminance and chrominance signal components of a composite video signal. The frame-to-frame changes in the luminance signal are detected, and a motion signal is derived therefrom. The higher frequency portion of the luminance signal is adaptively de-emphasized in amplitude and folded into the spectrum of the lower frequency portion of the luminance signal, to generate a folded-spectrum luminance signal for modulating the frequency of a luma carrier. In a combined signal, suitable for magnetic recording in accordance with a modified VHS standard, the chrominance signal is translated in frequency to generate a color-under signal in a frequency band below that occupied by the FM luma carrier. The de-emphasized higher frequency portion of the luminance signal, as folded into its lower frequency portion, and encoding of the motion signal onto vacant portions of the frequency band below that occupied by the FM luma carrier in such a magnetic recording facilitate its being compatibly reproduced by conventional VHS reproduction devices. In a wideband reproduction device a decoder demodulates the folded-spectrum luminance signal from the FM luma carrier, unfolds the lumininance signal, and reemphasizes the high frequencies of the unfolded luminance signal. The color-under signal is translated in frequency to regenerate chrominance signal combined with the unfolded luminance signal with its high frequencies re-emphasized to their original amplitude, regenerating a composite signal descriptive of a full bandwidth image. The motion signal is utilized in the encoder for motion-adaptively pre-filtering the input luminance and is recovered in the decoder for motion-adaptively post-filtering the unfolded luminance.
摘要翻译：编码器分离复合视频信号的亮度和色度信号分量。检测亮度信号中的帧到帧的变化，并从中导出运动信号。亮度信号的较高频率部分在幅度上自适应去强调，并折射成亮度信号的较低频率部分的频谱，以产生用于调制亮度载波频率的折射谱亮度信号。在适合于根据修改的VHS标准的磁记录的组合信号中，色度信号被频率转换，以在低于由FM亮度载波占据的频带内产生下色信号。亮度信号的去加重的较高频率部分被折叠成其较低频率部分，并且将运动信号编码到在这种磁记录中由FM亮度载波占据的频带以下的频带的空的部分上，便于其兼容由常规VHS再现设备再现。在宽带再现装置中，解码器解调来自FM亮度载波的折叠频谱亮度信号，展开亮度信号，并重新强调展开的亮度信号的高频。彩色信号以频率转换以再现与展开的亮度信号组合的色度信号，其高频被再次强调到其原始幅度，再生描述全带宽图像的复合信号。运动信号在编码器中用于对输入亮度进行运动自适应预滤波，并在解码器中恢复运动自适应地对展开后的亮度进行后置滤波。

你已经成功收藏专利！

检索式保存成功!

IPRDB

热门服务

关于我们

友情链接

联系方式