Patent ID: 7356087
Filing Date: 2008-04-08
Classification: H04L

Abstract:
1. A method for forming and transmitting a communication including mapping m input bits to 2 m modulation symbols of a two-dimensional symbol constellation, where m is a positive integer greater than or equal to four, the method comprising: forming a quarter-quadrant constellation of 2 uniquely associating each modulation symbol of the quarter-quadrant constellation with a respective m-4 bit label of the m input bits; forming a quarter constellation of the two-dimensional symbol constellation by adding to the quarter-quadrant constellation three copies of the quarter-quadrant constellation rotated by −90 degrees, 180 degrees, and −270 degrees, respectively, and then displacing the quarter constellation by a shift value Δ such that the symbols coincide with symbols of the two-dimensional symbol constellation, wherein the quarter constellation has one-fourth the size of the two-dimensional symbol constellation; uniquely associating each symbol of the quarter constellation with a respective m-2 bit label of the m input bits, wherein m-4 bits of the m-2 bit label are inherited from the quarter-quadrant constellation and two further bits of the m-2 bit label are used to distinguish quarter-quadrants of the quarter constellation; forming the two-dimensional symbol constellation by adding to the quarter constellation three copies of the quarter constellation rotated by +90 degrees, 180 degrees, and +270 degrees, respectively; uniquely associating each symbol of the two-dimensional symbol constellation with an m-bit label, wherein m-2 bits of the m-bit label are inherited from the quarter constellation and two further bits of the m input bits are used to distinguish quarters of the two-dimensional symbol constellation; and for each of a plurality of groups of m input bits: