Patent ID: 7356087

Claim:
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 m-4 modulation symbols that are located in a first quadrant of the two-dimensional signal plane, the quarter-quadrant constellation having one-sixteenth the size of the two-dimensional symbol constellation; 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 âˆ’90 degrees, 180 degrees, and âˆ’270 degrees, respectively, and then displacing the quarter constellation by a shift value Î” 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: mapping each group of m input bits to the two-dimensional symbol constellation to form a communication symbol; and transmitting the communication symbol.