US Patent 7953033 Method of signalling, a communication system and a communication equipment

First and second data is transmitted simultaneously by modulating a first set of signal constellation points, corresponding to the first data, with second data thereby creating a second set of constellation points. The second set of constellation points comprises two subsets corresponding to two values of the first data. The constellation points are selected such that the minimum distance between the first and second subsets is not less than the minimum distance between the constellation points of the first set of constellation points.