公开(公告)号：US20150358035A1

公开(公告)日：2015-12-10

申请号：US14714780

申请日：2015-05-18

Applicant: Sirius XM Radio Inc.

Inventor： Carl Scarpa ,  Edward Schell

IPC: H03M13/27 ,  H03M13/11

CPC classification number: H03M13/1105 ,  H03M13/1102 ,  H03M13/2732 ,  H03M13/2746 ,  H03M13/2771 ,  H03M13/2792 ,  H04B7/1858 ,  H04L1/0057 ,  H04L1/0071

Abstract: Systems, methods and apparatus are described to interleave LDPC coded data for reception over a mobile communications channel, such as, for example, a satellite channel. In exemplary embodiments of the present invention, a method for channel interleaving includes segmenting a large LDPC code block into smaller codewords, randomly shuffling the code segments of each codeword and then convolutionally interleaving the randomly shuffled code words. In exemplary embodiments of the present invention, such random shuffling can guarantee that no two consecutive input code segments will be closer than a defined minimum number of code segments at the output of the shuffler. In exemplary embodiments of the present invention, by keeping data in, for example, manageable sub-sections, accurate SNR estimations, which are needed for the best possible LDPC decoding performance, can be facilitated based on, for example, iterative bit decisions.

Abstract translation: 描述了系统，方法和装置来交织用于通过诸如卫星信道的移动通信信道进行接收的LDPC编码数据。 在本发明的示例性实施例中，一种用于信道交织的方法包括将大型LDPC码块分割成较小的码字，随机混洗每个码字的码片段，然后对随机混洗码字进行卷积交织。 在本发明的示例性实施例中，这种随机混洗可以保证在洗牌器的输出处没有两个连续的输入代码段将比规定的最小数量的代码段更接近。 在本发明的示例性实施例中，通过将数据保存在例如可管理子部分中，可以基于例如迭代比特决定来促进针对最佳LDPC解码性能所需的精确SNR估计。

公开(公告)号：US20130121350A1

公开(公告)日：2013-05-16

申请号：US13646099

申请日：2012-10-05

Applicant: Sirius XM Radio, Inc.

Inventor： Carl Scarpa ,  Edward Schell ,  Christopher Strolle

IPC: H04L27/26

CPC classification number: H04L27/2627 ,  H04L5/0007 ,  H04L5/0028 ,  H04L27/0008 ,  H04L27/0012 ,  H04L27/183 ,  H04L27/2053 ,  H04L27/2071 ,  H04L27/3488 ,  H04L2025/03401 ,  H04L2025/03414

Abstract: Systems and methods are presented for transmitting additional data over preexisting differential COFDM signals by modulating existing data carriers with a phase and an amplitude offset. In exemplary embodiments of the present invention, additional data capacity can be achieved for an COFDM signal which is completely backwards compatible with existing satellite broadcast communications systems. In exemplary embodiments of the present invention additional information can be overlayed on an existing signal as a combination of amplitude and phase offset from the original QPSK symbols, applied for each information bit of the overlay data. With two additional levels of modulation, a receiver can demodulate the information from each of the previous stages and combine the information into a suitable format for soft decoding. The first stage of demodulation will be recovery of overlay data from the amplitude modulated D8PSK. Because other amplitude variations due to multi-path are also expected, the data gathered from the FFT in the receiver must be equalized to the channel conditions. After channel equalization has been performed, soft overlay data can then be derived from the distance off the unit circle. In order to recover the phase modulated overlay data, the equalized symbols must first be differentially demodulated and corrected for any common phase error offset. After common phase removal, overlay phase information can be obtained.

Abstract translation: 提出了系统和方法，用于通过调制具有相位和幅度偏移的现有数据载波来传输先前存在的差分COFDM信号的附加数据。 在本发明的示例性实施例中，可以实现与现有卫星广播通信系统完全向后兼容的COFDM信号的附加数据容量。 在本发明的示例性实施例中，作为叠加数据的每个信息比特的原始QPSK符号的幅度和相位偏移的组合，附加信息可以叠加在现有信号上。 通过两个附加的调制级别，接收机可以解调来自每个先前阶段的信息，并将该信息组合成用于软解码的适当格式。 解调的第一阶段将是从幅度调制的D8PSK恢复覆盖数据。 由于也预期由于多路径引起的其他幅度变化，所以从接收机中从FFT收集的数据必须与信道条件相等。 在执行信道均衡之后，可以从距离单位圆的距离导出软覆盖数据。 为了恢复相位调制覆盖数据，必须首先对均衡的符号进行差分解调并校正任何公共相位误差偏移。 共相除去后，可以获得覆盖相位信息。