公开(公告)号：US08983009B2

公开(公告)日：2015-03-17

申请号：US13760361

申请日：2013-02-06

Applicant: Imagination Technologies Limited

Inventor： Mohammed El-Hajjar ,  Paul Murrin ,  Adrian J. Anderson

IPC: H04L27/06 ,  H04L1/00 ,  H04L25/06 ,  H04L27/38 ,  H04L27/26

CPC classification number: H04L27/2647 ,  H03M13/41 ,  H04L1/0054 ,  H04L1/06 ,  H04L1/0618 ,  H04L25/067 ,  H04L27/38

Abstract: Methods and apparatus for efficient demapping of constellations are described. In an embodiment, these methods may be implemented within a digital communications receiver, such as a Digital Terrestrial Television receiver. The method reduces the number of distance metric calculations which are required to calculate soft information in the demapper by locating the closest constellation point to the received symbol. This closest constellation point is identified based on a comparison of distance metrics which are calculated parallel to either the I- or Q-axis. The number of distance metric calculations may be reduced still further by identifying a local minimum constellation point for each bit in the received symbol and these constellation points are identified using a similar method to the closest constellation point. Where the system uses rotated constellations, the received symbol may be unrotated before any constellation points are identified.

Abstract translation: 描述了有效地拆分星座的方法和装置。 在一个实施例中，这些方法可以在诸如数字地面电视接收机的数字通信接收机内实现。 该方法减少了通过将最接近的星座点定位到接收到的符号来计算解映射器中的软信息所需的距离度量计算的数量。 基于与I轴或Q轴平行计算的距离度量的比较来识别最接近的星座点。 通过识别接收到的符号中的每个位的局部最小星座点，可以进一步减少距离度量计算的数量，并且使用与最接近的星座点类似的方法来识别这些星座点。 在系统使用旋转星座的地方，在识别出任何星座点之前，接收到的符号可能未旋转。