Patent ID: 7742699

Claim:
A method for the optical transmission of data signals via differential binary phase modulation in a polarization multiplex method, comprising: modulating, on a send side, an optical carrier signal with a first data signal via a binary differential phase modulation to form a first polarized transmission signal with two phase states differing by 180° and with a first polarization; modulating the optical carrier signal with a second data signal via a DBPSK-modulation to form a second polarized transmission signal with a polarization that is orthogonal with respect to the first transmission signal, whose odd modulation sections are transmitted as two phase states differing by 180° and whose even modulation sections are likewise generated as phase states which differ by 180° but which exhibit an additional ±90° phase shift when compared with the odd bits; combining the first and second transmission signals to form a polarization multiplex signal; transmitting the polarization multiplex signal; splitting the received polarization multiplex signal into a first and a second POLMUX partial signal via an optical splitter; demodulating the first POLMUX partial signal via a DBPSK demodulator; and demodulating the second POLMUX partial signal via a π/2 DBPSK demodulator which compensates for the additional phase shift of the carrier signal.