公开(公告)号：US20160134452A1

公开(公告)日：2016-05-12

申请号：US14874872

申请日：2015-10-05

Applicant: Sirius XM Radio Inc.

Inventor： Carl SCARPA

IPC: H04L27/22 ,  H04B1/10

CPC classification number: H04L27/22 ,  H04B1/1027 ,  H04L27/3466

Abstract: In exemplary embodiments of the present invention, a degree of hierarchical modulation can be varied as a function of satellite position, which can be related to time of day, and where such hierarchical modulation can be a combination of phase and amplitude shifts. In exemplary embodiments of the present invention, as each satellite in a multiple satellite system broadcasting to North America moves towards a D-node or an A-node position, the offset angle of a phase-based hierarchical modulation scheme can be varied. Thus, in exemplary embodiments of the present invention, the lowest satellite position in the sky can have the lowest offset angle for overlay bits, which offset angle can, for example, progressively increase as the position of the satellite in the sky increases. At a satellite's highest point in the sky, the overlay offset angle can, for example, thus be at its maximum. To aid a receiver to receive such varying overlay modulated data, the value of a varying overlay offset angle (for each satellite) can be embedded in an Overlay Identification Marker (OIM) in the bit stream broadcast by that satellite. In exemplary embodiments of the present invention each satellite broadcast receiver can thus decode each satellite's signal, knowing its respective instantaneous overlay offset angle. The receiver can then use this information to appropriately correct MRC weightings (weighting more heavily the (higher lying) satellite with the higher degree of Layer 2 modulation) before it is MRC combined across various received signal streams. Similar methods can be implemented for other overlay modulation techniques, and the method can be extended to a broadcast system using N satellites, each having a varying degree of Layer 2 modulation.

Abstract translation: 在本发明的示例性实施例中，分级调制的程度可以随卫星位置的函数而变化，这可以与时间有关，并且其中这种分层调制可以是相位和幅度相移的组合。 在本发明的示例性实施例中，由于向北美广播的多个卫星系统中的每个卫星朝向D节点或A节点位置移动，因此可以改变基于相位的分层调制方案的偏移角。 因此，在本发明的示例性实施例中，天空中最低的卫星位置可以具有覆盖比特的最低偏移角，当天空中的卫星的位置增加时，偏移角可以例如逐渐增加。 在卫星的天空最高点，覆盖偏移角例如可以达到最大值。 为了帮助接收机接收这种变化的重叠调制数据，可以将该改变的覆盖偏移角（对于每个卫星）的值嵌入在由该卫星广播的比特流中的覆盖识别标记（OIM）中。 在本发明的示例性实施例中，每个卫星广播接收机可以解码每个卫星的信号，知道其相应的瞬时覆盖偏移角。 然后，接收机可以在MRC组合在各种接收信号流之前，使用该信息来适当地校正MRC权重（用较高层次的2调制度对更高级别的卫星进行加权）。 可以对其他覆盖调制技术实现类似的方法，并且该方法可以扩展到使用N个卫星的广播系统，每个卫星具有不同程度的第2层调制。