Patent ID: 8407570
Filing Date: 2013-03-26
Classification: H03M,H04L

Abstract:
1. A fractional decoder for decoding a received signal vector modulated using a signaling scheme based on a multi-dimensional modulation scheme, wherein the signaling scheme uses at most half of available signal point vectors in the multi-dimensional modulation scheme, the fractional decoder comprising: a neighbor finder for identifying a first set of nearest neighbors and a second set of nearest neighbors, wherein the second set of nearest neighbors includes signal points further from the received signal vector than corresponding signal points in the first set; a signal validator for determining whether each of a plurality of potential signal vectors, formed from the identified first set of nearest neighbors, is a signal point vector that is part of the signaling scheme, wherein each of the plurality of potential signal vectors are grouped into cosets, and wherein each of the plurality of potential signal vectors determined to be part of the signaling scheme comprise a first group of valid potential signal vectors; control logic for replacing, in each valid potential signal vector in the first group, a signal point in the first set of nearest neighbors with a signal point in the second set of nearest neighbors to produce a second group of valid potential signal vectors; and a detector for identifying one of the cosets based on branch metrics computed based on the first group and the second group of valid potential signal vectors.