Patent ID: 8249190
Filing Date: 2012-08-21
Classification: H04B,H04L

Abstract:
1. A coding unit for determining two different types of modulation to be applied to two carrier signals such that each modulated carrier signal represents a data symbol in accordance with a group of modulation points, each modulation point representing a modulation of the first type and a modulation of the second type that can be applied to one of the carrier signals, the coding unit comprising: a mapping unit that associates an input data symbol with a first one of the modulation points by applying a first mapping function to the input data symbol and also associates the input data symbol with a second one of the modulation points by applying a second mapping function to the input data symbol, the first and second mapping functions being such that they each map two different data symbols to a respective common modulation point, and such that a first data symbol that is associated with a first modulation point that is the same as a first modulation point of another data symbol is associated with a second modulation point that is different from the second modulation point of said other data symbol; and a modulation determination unit that determines the modulations of the first and second types to be applied to the first carrier signal to be the modulations of the first and second types represented by the first modulation point and the modulations of the first and second types to be applied to the second carrier signal to be the modulations of the first and second types represented by the second modulation point, and outputs control signals to modulator circuitry that modulates said carrier signals in accordance with the determined modulations.