Methods for assigning codewoods to points in hexagonal constellations in digital communication systems

摘要

Embodiments of the invention provide a methods for the assignment of codewords to the available constellation points to minimize the Hamming distance between adjacent codewords. An hexagonal constellation is modeled as a two-dimensional trellis with an horizontal axis varying across a plurality of constellation points and a vertical axis varying across a plurality of codewords [0, 1, . . . , N−1]. A best path through the trellis is found to select a single constellation point per each codeword where a codeword is to be assigned. A each state in the transition across the trellis diagram, a current score and the best path that leads to the state is stored in a memory. Each codeword is assigned to the selected constellation point. The hexagonal constellation is used for transmitting data in a communication system.

主权项

1. A method comprising:
modeling an hexagonal constellation as a two-dimensional trellis with an horizontal axis varying across a plurality of constellation points and a vertical axis varying across a plurality of codewords [0, 1, . . . , N−1]; finding a best path through the trellis to select a single constellation point per each codeword where a codeword from the plurality of codewords is to be assigned in the transition across the trellis diagram, at each state, a current score and the best path that leads to the state is stored in a memory; assigning each codeword of the plurality of codewords to the selected constellation point from the plurality of constellation points for a hexagonal constellation; and using the hexagonal constellation for transmitting data.