DIGITAL CORRECTION TECHNIQUES FOR DATA CONVERTERS
    6.
    发明申请
    DIGITAL CORRECTION TECHNIQUES FOR DATA CONVERTERS 有权
    数据转换器的数字校正技术

    公开(公告)号:US20120235841A1

    公开(公告)日:2012-09-20

    申请号:US13228301

    申请日:2011-09-08

    IPC分类号: H03M1/06

    摘要: A method and apparatus is disclosed to compensate for impairments within a data converter such that its output is a more accurate representation of its input. The data converter includes a main data converter, a reference data converter, and a correction module. The main data converter may be characterized as having the impairments. As a result, the output of the main data converter is not the most accurate representation of its input. The reference data converter is designed such that the impairments are not present. The correction module estimates the impairments present within the main data converter using its output and the reference data converter to generate corrections coefficients. The correction module adjusts the output of the main data converter using the corrections coefficients to improve the performance of the data converter.

    摘要翻译: 公开了一种用于补偿数据转换器内的损伤的方法和装置,使得其输出是其输入的更准确的表示。 数据转换器包括主数据转换器,参考数据转换器和校正模块。 主数据转换器可以被表征为具有损伤。 因此,主数据转换器的输出不是其输入的最准确的表示。 参考数据转换器被设计成不存在损伤。 校正模块使用其输出和参考数据转换器来估计存在于主数据转换器内的损伤以产生校正系数。 校正模块使用校正系数调整主数据转换器的输出,以提高数据转换器的性能。

    Viterbi slicer for turbo codes
    7.
    发明申请
    Viterbi slicer for turbo codes 有权
    涡轮代码维特比切片机

    公开(公告)号:US20090122925A1

    公开(公告)日:2009-05-14

    申请号:US12358362

    申请日:2009-01-23

    IPC分类号: H04L27/06

    摘要: A method for synchronizing receivers that receive turbo encoded signals to a received signal. Turbo encoding may enable signals to be decoded at a much lower signal to noise ratio than previously practical. A traditional method of synchronizing a receiver to an incoming signal is to use a slicer to determine a received symbol and then to compare the determined symbol to the incoming waveform, in order to adjust the phase of the slicer with respect to the incoming signal. At signal low levels, at which turbo encoded signals may be decoded, this slicing method may be prone to errors that may disrupt the synchronization of the receiver to the incoming signal. By replacing the slicer by a Viterbi decoder with zero traceback (i.e., one which does not consider future values of the signal only past values) a prediction as to what the incoming signal is can be made. Because the Viterbi decoder can consider past signal values it can predict the present symbol being received with higher reliability than by using a slicer, which considers only the present value of the incoming signal.

    摘要翻译: 一种用于将接收turbo编码信号的接收机同步到接收信号的方法。 Turbo编码可以使信号以比以前实际的低得多的信噪比进行解码。 将接收机同步到传入信号的传统方法是使用限幅器来确定接收到的符号,然后将确定的符号与输入波形进行比较,以便相对于输入信号调节限幅器的相位。 在信号低电平处,可以对Turbo编码信号进行解码,该分片方法可能容易出现可能中断接收机与输入信号的同步的错误。 通过用零回溯的维特比解码器(即,不将信号的未来值仅仅考虑过去的值)来替换限幅器,可以对可以进行什么输入信号进行预测。 因为维特比解码器可以考虑过去的信号值,所以它可以比使用仅考虑输入信号的当前值的限幅器更可靠地预测接收到的当前码元。

    Timing recovery using the pilot signal in high definition TV
    8.
    发明授权
    Timing recovery using the pilot signal in high definition TV 有权
    使用高分辨率电视中的导频信号进行定时恢复

    公开(公告)号:US07027528B2

    公开(公告)日:2006-04-11

    申请号:US10895579

    申请日:2004-07-21

    IPC分类号: H04L27/14

    摘要: Improved carrier recovery and symbol timing systems and methods suitable for use in connection with a dual-mode QAM/VSB receiver system is disclosed. Carrier and symbol timing acquisition and tracking loops are phase/frequency locked to an inserted pilot signal provided in an input VSB spectrum at a given frequency. An input spectrum is centered about baseband and the pilot is extracted by an equivalent filter which functions as a bandpass filter having pass bands centered about the pilot frequency. Since the pilot signal's frequency is given, its position in the frequency domain for any sampling frequency, is deterministic. The receiver's sampling frequency is provided such that the relationship is expressed as fc=fS/4. When tracked by a phase-lock loop, the pilot signal will appear at the correct location in the spectrum if the sampling frequency fS is correct, and will be shifted in one direction or the other if the sampling frequency fS is too high or too low.

    摘要翻译: 公开了适用于双模QAM / VSB接收机系统的改进的载波恢复和符号定时系统和方法。 载波和符号定时采集和跟踪环路被相位/频率锁定到在给定频率下在输入VSB频谱中提供的插入导频信号。 输入频谱以基带为中心,并且通过等效滤波器提取导频,该等效滤波器用作具有以导频频率为中心的通带的带通滤波器。 由于给出了导频信号的频率,所以在频域中对于任何采样频率的位置是确定性的。 提供了接收机的采样频率,使得该关系被表示为f / c = f S / S / 4。 当通过锁相环路进行跟踪时,如果采样频率f S S S正确,则导频信号将出现在频谱中的正确位置,并且如果采样 频率f S S太高或太低。

    Data placement on tape for a digital video tape recorder suitable for
high speed picture playback
    10.
    发明授权
    Data placement on tape for a digital video tape recorder suitable for high speed picture playback 失效
    适用于高速图像播放的数字录像机的磁带上的数据放置

    公开(公告)号:US5574565A

    公开(公告)日:1996-11-12

    申请号:US335211

    申请日:1994-10-28

    摘要: A video tape includes a plurality of parallel slant tracks formed therein. Each track includes a plurality of successively recorded sync blocks. In each sync block, a respective portion of a first digital signal recorded therein represents a predetermined portion of an input image with relatively low resolution, and a respective portion of a second digital signal recorded therein represents substantially the same predetermined portion of the input image with relatively high resolution. Successive sync blocks include consecutive portions of the first digital signal, which portions correspond to spatially adjacent portions of the input image. Preferably, each sync block includes a fixed number of bits of the first digital signal, which is decodable without reference to any image coded signal from other sync blocks. The first digital signal codes the input images as raster scanned in reduced-resolution form for reproduction during a trickplay mode and the second digital signal comprises variable-bit-length codes permitting reproduction of the input images in full-resolution form during a normal-play mode. The second digital signal is not decodable unless there is reference to the portion of the first digital signal recorded in the same sync block, or portions of the second digital signal in other ones of the sync blocks, or to the portion of the first digital signal recorded in the same sync block and portions of the second digital signal in other ones of the sync blocks.

    摘要翻译: 视频磁带包括形成在其中的多个平行斜线。 每个轨道包括多个连续记录的同步块。 在每个同步块中,其中记录的第一数字信号的相应部分表示具有相对低分辨率的输入图像的预定部分,并且其中记录的第二数字信号的相应部分表示输入图像的基本相同的预定部分, 相对较高的分辨率。 连续同步块包括第一数字信号的连续部分,哪些部分对应于输入图像的空间相邻部分。 优选地,每个同步块包括第一数字信号的固定数量的比特,其可解码,而不参考来自其他同步块的任何图像编码信号。 第一数字信号将输入图像编码为在特技播放模式期间以降低分辨率形式扫描的光栅进行再现,并且第二数字信号包括允许在正常播放期间以全分辨率形式再现输入图像的可变比特长度码 模式。 第二数字信号不能解码,除非参考记录在同一同步块中的第一数字信号的部分,或其他同步块中的第二数字信号的部分,或第一数字信号的部分 记录在相同的同步块中,并且第二数字信号的部分在其他同步块中。