专利快速检索-快速检索全球专利，免费商用专利数据库-IPRDB

21. 发明公开

EP0962083A2 METHOD AND APPARATUS FOR DETECTING CORRUPT PILOTS IN THE RECEPTION OF ORTHOGONAL FREQUENCY DIVISION MULTIPLEX (OFDM) SIGNALS 失效
标题翻译：用于检测方法及装置伪造的飞行员在接受正交FREQUENZMULTIPLEXSIGNALEM（OFDM）
公开(公告)号：EP0962083A2
公开(公告)日：1999-12-08
申请号：EP98905119.0
申请日：1998-02-20
申请人： NDS LIMITED
发明人： TURNER, Adrian, Charles , DEALTRY, Roger, Paul
IPC分类号： H04L27
CPC分类号： H04L27/2647
摘要： This invention relates generally to transmitting and receiving frequency division multiplex signals and, more precisely, to a method and apparatus for transmitting and receiving orthogonal frequency division multiplex (OFDM) signals. OFDM signals may include both data carriers and reference carriers (or pilots). The pilot signals are transmitted at known positions with a known phase and amplitude, however distortions in the transmission channel can adversely affect the data received at a receiver. Pilots are used by a receiver to correct the data carriers which may have been affected by distortion or interference in the transmission channel. However, if a pilot signal is corrupted during transmission this can lead to the data carriers being erroneously corrected. The present invention seeks to provide a method and apparatus for receiving a frequency division multiplex signal in which the effect of corrupt pilot signals can be monitored and reduced.

22. 发明公开

EP0961216A2 IC card-based test apparatus and method 有权
标题翻译： ChipkartenbasierendesPrüfverfahrenund Vorrichtung
公开(公告)号：EP0961216A2
公开(公告)日：1999-12-01
申请号：EP99200839.1
申请日：1999-03-17
申请人： NDS LIMITED
发明人： Adler, Michael
IPC分类号： G06K7/00 , G06K19/07 , G06F11/273 , G01R31/00
CPC分类号： G06F11/261 , G06K7/0008
摘要： This invention discloses a device for testing a smart card interface, including a mimic of a smart card designed for the interface; and test electronics for measuring parameters of signals output by the interface.
摘要翻译：本发明公开了一种用于测试智能卡接口的设备，包括为接口设计的智能卡的模仿; 并测试电子设备，用于测量由接口输出的信号的参数。

23. 发明公开

EP0948215A2 Filtering video signals containing chrominance information 有权
标题翻译： Verfahren und Vorrichtung zum Filnt von Videosignalen mit Chrominanzinformation
公开(公告)号：EP0948215A2
公开(公告)日：1999-10-06
申请号：EP99200597.5
申请日：1999-03-03
申请人： NDS LIMITED
发明人： Baudouin, Charles
IPC分类号： H04N9/64
CPC分类号： H04N9/646
摘要： The present invention relates to filtering an interlaced input digital signal containing fields of chrominance information preparatory to converting the format of the signal by means of a downsampling conversion from a 4:2:2 format to a 4:2:0 format.
In the invention, the input signal is applied to a delay circuit to derive samples of the input signal representing spatially separated elements from each chrominance field where the spatial separation is of one line. The magnitudes of the samples are compared relative to one another to identify frequencies which fall within different high and low frequency ranges. An adaptive filter has a plurality of frequency responses corresponding to the frequency ranges and a frequency response is selected in accordance with the identified frequency range of the input signal samples.
摘要翻译：本发明涉及滤波包含色度信息领域的隔行输入数字信号，准备通过从4：2：2格式的下采样转换为4：2：0格式来转换信号的格式。在本发明中，输入信号被施加到延迟电路以从空间分离为一行的每个色度场导出代表空间分离的元素的输入信号的样本。将样本的幅度相对于彼此进行比较，以识别属于不同高频和低频范围内的频率。自适应滤波器具有对应于频率范围的多个频率响应，并且根据所识别的输入信号样本的频率范围来选择频率响应。

24. 发明公开

EP0948207A1 Method and apparatus for processing a digital signal 审中-公开
标题翻译： Datenverarbeitungsverfahren und-gerät
公开(公告)号：EP0948207A1
公开(公告)日：1999-10-06
申请号：EP99200581.9
申请日：1999-03-02
申请人： NDS LIMITED
发明人： Murray, Kevin Alistair , Davies, Colin , Bock, Alois Martin , Huggett, Anthony Richard , Funnel, John Stuart , Warburton, Richard John , Stubbings, Clive Anthony
IPC分类号： H04N7/26
CPC分类号： H04N19/436 , H04N19/30
摘要： The present invention relates to digital television, and in particular the encoding of high-definition television (HDTV).
Standard digital television pictures have a resolution of 480 x 704 pixels and display at 30 frames per second. High definition television (HDTV) differs from standard television in having a much higher resolution.
The generation of digitally compressed HDTV signals requires dedicated encoding equipment due to the high sampling rates used for HDTV signals. Consequently, due to their increased complexity, HDTV encoders are substantially more complex and expensive than standard TV encoders.
A standard television encoder is not capable of encoding a HDTV image due to the increased resolution and the much larger data rates associated with such large images which is outside of capacity of a standard television encoder.
The present invention overcomes these problems and provides a method and apparatus for creating HDTV signals using predominantly standard television equipment.
摘要翻译：本发明涉及数字电视，特别涉及高分辨率电视（HDTV）的编码。标准数字电视图像的分辨率为480×704像素，每秒30帧显示。高分辨率电视（HDTV）与标准电视的分辨率不同。数字压缩的HDTV信号的产生由于用于HDTV信号的高采样率而需要专用的编码设备。因此，由于HDTV编码器的复杂性越来越高，比标准电视编码器要复杂得多。标准电视编码器由于分辨率的增加而不能编码HDTV图像，并且与标准电视编码器容量之外的这种大图像相关联的数据速率大得多。本发明克服了这些问题，并且提供了使用主要标准的电视设备来创建HDTV信号的方法和装置。

25. 发明公开

EP0939526A2 Carrier recovery for MPSK signals 审中-公开
标题翻译： TrägerrückwinnungfürMPSK-Sigale
公开(公告)号：EP0939526A2
公开(公告)日：1999-09-01
申请号：EP99200312.9
申请日：1999-02-03
申请人： NDS LIMITED
发明人： Markarian, Garegin
IPC分类号： H04L27/227
CPC分类号： H04L27/2273 , H04L2027/0057 , H04L2027/0071
摘要： The present invention relates to the recovery of a carrier phase from a modulated input signal where the modulation is in accordance with the M-PSK modulation format, M has a value greater than 4 and the signal-to-noise ratio in the channel is low.
A voltage controlled oscillator is employed to generate first and second oscillations in phase quadrature with respect to each other. The modulated input signal is mixed with the first of the oscillations to detect the (I) signal component and the modulated input signal is mixed with the second of the oscillations to detect the (Q) signal component. A control signal is derived from the (I) and (Q) signal components as an estimate of the phase difference between the input signal carrier and the voltage controlled oscillator. The control signal conforms to the relationship: where 'a' is the control signal, 'k' is an odd integer between 1 and M, and C k m represent binominal coefficients.
The frequency of the voltage controlled oscillator is controlled by the control signal to recover the carrier phase.
摘要翻译：本发明涉及从其中调制符合M-PSK调制格式的调制输入信号恢复载波相位，M具有大于4的值，并且信道中的信噪比低。采用压控振荡器来产生彼此相位正交的第一和第二振荡。调制输入信号与第一振荡混合以检测（I）信号分量，调制输入信号与第二振荡混合以检测（Q）信号分量。控制信号从（I）和（Q）信号分量导出为输入信号载波和压控振荡器之间的相位差的估计。控制信号符合以下关系： $其中'a'是控制信号，'k'是1和M之间的奇整数，Ck_m表示二进制系数。压控振荡器的频率由控制信号控制，以恢复载波相位。$

26. 发明公开

EP0933945A2 Digital signal processing 审中-公开
标题翻译： Digitale Signalverarbeitung
公开(公告)号：EP0933945A2
公开(公告)日：1999-08-04
申请号：EP99101354.1
申请日：1999-01-26
申请人： NDS LIMITED
发明人： Davies, Colin , Brown, Derek William
IPC分类号： H04N7/26
CPC分类号： H04N19/60 , H04N19/97
摘要： According to the present invention there is provided a method and processing apparatus for producing a representation of a digital signal in terms of a plurality of basis functions. A first processor determines a basis function for each of a plurality of portions of the signal. A second processor periodically determines a correction coefficient for each basis function. A generator generates a basis function structure book based on the original basis function and the correction coefficient.
This has the advantage of improving the efficiency of the Matching Pursuits process and generating a more accurate basis function structure book.
摘要翻译：根据本发明，提供一种用于根据多个基本功能产生数字信号的表示的方法和处理装置。第一处理器确定信号的多个部分中的每一个的基函数。第二处理器周期性地确定每个基函数的校正系数。发生器基于原始基函数和校正系数生成基函数结构图。这具有提高匹配追求过程的效率并生成更准确的基础功能结构书的优点。

27. 发明公开

EP0933943A2 Digital signal processing 审中-公开
标题翻译： Digitale Signalverarbeitung
公开(公告)号：EP0933943A2
公开(公告)日：1999-08-04
申请号：EP99101352.5
申请日：1999-01-26
申请人： NDS LIMITED
发明人： Davies, Colin
IPC分类号： H04N7/26
CPC分类号： H04N19/60 , G06T1/20 , H04N19/85 , H04N19/97
摘要： According the present invention there is provided apparatus for matching a plurality of functions to a digital signal so as to represent the digital signal in terms of said functions comprising a first processor for determining one or more common factors in the plurality of functions; and means for representing at least some of the functions in terms of one or more others of said functions thereby to reduce the amount of processing necessary for the matching.
This has the advantage that there is no unnecessary processing to determine the basis functions. Where there is commonality and the process would require less processing potential to make use of this than not then the commonality is exploited.
摘要翻译：根据本发明，提供了用于将多个功能与数字信号进行匹配的装置，以便在所述功能方面表示数字信号，该功能包括用于确定多个功能中的一个或多个共同因素的第一处理器; 以及用于根据所述功能中的一个或多个其他方式表示至少一些功能的装置，从而减少匹配所需的处理量。这样做的优点是没有不必要的处理来确定基础功能。如果共同点和过程需要较少的处理潜力来利用这个而不是那么共同性被利用。

28. 发明公开

EP0929976A1 METHOD AND APPARATUS FOR MOTION ESTIMATION 失效
标题翻译：用于运动估计的方法和设备
公开(公告)号：EP0929976A1
公开(公告)日：1999-07-21
申请号：EP97943960.0
申请日：1997-09-26
申请人： NDS LIMITED
发明人： BOCK, Alois, Martin
IPC分类号： H04N7
CPC分类号： H04N19/567 , H04N19/51
摘要： The present invention relates to a method of generating and transmitting digitally encoded signals in which portions of the code are predicted from earlier. The invention is applied to a digital video compression system in which temporal predictive coding is used in order to reduce the data rate of the transmitted signal. Predictions are made for the reconstruction of the current picture based on elements of pictures that have been coded in the past. A prediction is made for each reference block from each of five picture areas. A distortion value is derived for each prediction and a selection is made from the predictions based on the distortion values of the predictions. By biasing the selection between the different predictions towards that prediction which was last selected, predictions of approximately equal quality from completely different picture areas will be avoided. This avoids the situation where small advantages in prediction quality are outweighed by a larger codeword for the transmission of the prediction.
摘要翻译：本发明涉及一种产生和传输数字编码信号的方法，其中部分代码是从较早的时间预测的。本发明应用于数字视频压缩系统，其中使用时间预测编码以降低发送信号的数据速率。基于过去编码的图像元素对当前图像进行预测。对来自五个图片区域中的每一个的每个参考块进行预测。为每个预测导出失真值，并根据预测的失真值从预测中进行选择。通过在不同的预测之间偏向于最后选择的预测的选择，将避免来自完全不同图像区域的近似相等质量的预测。这避免了预测传输的较大代码字超过预测质量的小优点。

29. 发明公开

EP0886444A2 Filtering method to reduce block artifacts in digital video sequences 失效
标题翻译： Filterungsverfahren zur Reduzierung von Blockartefakten在digitalen Videosequenzen
公开(公告)号：EP0886444A2
公开(公告)日：1998-12-23
申请号：EP98110048.0
申请日：1998-06-02
申请人： NDS LIMITED
发明人： Bock, Alois Martin, Dr.
IPC分类号： H04N7/30
CPC分类号： H04N19/86
摘要： The present invention relates generally to the domain of digital signal processing and, more precisely, the methods and apparatus employed in the reduction of visibility of blockiness in images or video sequences encoded using block-based coding techniques such as MPEG.
The present invention detects a level of blockiness between blocks in an image and applies a variable filter across the block boundaries. The filter parameters are chosen depending on the level of blockiness detected. If no blockiness is detected then no filtering is performed on the image.
An important aspect of the present invention reduces the false detection of naturally occurring blockiness in images by analysing the image both spatially and temporally.
摘要翻译：本发明一般涉及数字信号处理的领域，更确切地说，涉及降低使用基于块的编码技术（例如MPEG）编码的图像或视频序列中的块效果的可视性的方法和装置。本发明检测图像中的块之间的块级，并跨越块边界应用可变滤波器。过滤器参数根据检测到的阻塞水平来选择。如果没有检测到阻塞，则不对图像执行滤波。本发明的一个重要方面通过在空间和时间上分析图像来减少图像中天然发生的块状物的错误检测。

30. 发明公开

EP0871337A2 Method and apparatus for modifying a digital data stream 失效
标题翻译： Verfahren und Vorrichtung zurVeränderungeines digitalen Datenstroms
公开(公告)号：EP0871337A2
公开(公告)日：1998-10-14
申请号：EP98302423.3
申请日：1998-03-30
申请人： NDS LIMITED
发明人： Bock, Alois Martin , Jordon, John Paul
IPC分类号： H04N7/52 , H04N7/32
CPC分类号： H04N7/52 , H04N19/152 , H04N19/50 , H04N21/234381 , H04N21/23611 , H04N21/2401
摘要： This invention relates to improvements in controlling the decoder buffer occupancy, particularly in relation to, but not exclusively to, switching between compressed bitstreams.
This invention provides a method of modifying a digital bitstream 11 to be transmitted through a decoder 14 having a buffer 15. An expected level of buffer occupancy is determined for a point in the digital bitstream 11 and the digital bitstream 11 is modified at that point to change the buffer occupancy to a second level. The second level may be determined from a second digital bitstream 12. One advantage of this method is that the occupancy of the buffer 15 can be adjusted to match the buffer requirements of the second bitstream 12 before switching to the second bitstream 12.
The invention provides method and apparatus for improving the decoder buffer management during switching between bitstreams.
摘要翻译：本发明涉及在控制解码器缓冲器占用方面的改进，特别是关于而不是排他地在压缩比特流之间进行切换。本发明提供了一种修改要通过具有缓冲器15的解码器14发送的数字比特流11的方法。为数字比特流11中的一个点确定预期的缓冲器占用水平，并且数字比特流11在该点修改为将缓冲区占用率更改为第二级。可以从第二数字比特流12确定第二级。该方法的一个优点是可以调整缓冲器15的占用以在切换到第二比特流12之前匹配第二比特流12的缓冲器要求。本发明提供用于在比特流之间切换期间改进解码器缓冲器管理的方法和装置。

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