A normalized modulation process that is differential in phase and coherent in amplitude for multi-user communications

• Main Authors: BADENES CORELLA, AGUSTIN, BLASCO CLARET, JORGE VICENTE, RIVEIRO INSUA, JUAN CARLOS
• Format: Patent
• Language: Chinese; English
• Published: 01.03.2005
• Subjects: ELECTRIC COMMUNICATION TECHNIQUE; ELECTRICITY; TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHICCOMMUNICATION

Applicable in a bi directional communication between multiple user modems in which a modulation that is differential in phase and coherent in amplitude is used, requiring that a phase reference symbol is sent prior to sending the information symbols; characterized because in the information to be modulated in the phase difference, which belongs to the set of possible information according to the number of phases in the constellation to be used, an injective function is carried out between this set and the set of possible information which corresponds to the constellation with the maximum number of phases, consisting of a projection of the elements of the first set in the same number of elements of the second set which produce the maximum separation, measured in radians, between the correspondent resultant points in the constellation with the maximum number of phases; so that the input information to the differential phase modulator belongs to this second set, and in this way, minimizing the overhead (system c