NORMALISED COHERENT AMPLITUDE AND DIFFERENTIAL PHASE MODULATION METHOD FOR MULTIUSER COMMUNICATION

摘要

The invention relates to a normalised coherent amplitude and differential phase modulation method for multi- user communications.The invention is characterised in that the information to be modulated in terms of phase difference, which belongs to a set of possible information according to the number of phases of the constellation to be used, contains a one-to-one mapping between the aforementioned set and the set of possible information to be modulated corresponding to the constellation with the maximum number of phases. In this way, bits can be changed by a carrier without sending a new phase reference, the number of information symbols in the frame can be maximised and a low-complexity modulator and demodulator can be used. The invention is suitable for use in multi-user digital communications which require the bits to be changed by the constellation carrier in one data frame, in order to be adapted to the maximum transmission capacity of the channel, to monitor the amplitude variations in same and to enable the transmission of information from one to various users.