Abstract: A received optical signal is coherently demodulated and converted into electrical complex samples, which are dispersion compensated in a compensation filter. A control circuit calculates comparison values from corrected samples and an estimated error value. A plurality of compensation functions is applied according to a predetermined dispersion range and after a second iteration, the compensation filter is set to an optimum compensation function.

Abstract: A method and a device are provided for phase recovery of at least two channels comprising the steps of (i) a phase is estimated for each channel; (ii) the phase estimated of each channel is superimposed by a coupling factor with at least one other phase estimated. Further, a communication system is suggested comprising such a device.

Abstract: A received optical signal is coherently demodulated and converted into orthogonal x-polarization samples, and y-polarization samples. These samples are converted into signal x-samples and signal y-samples by an FIR butterfly filter. Correction values are calculated in an error calculating circuit of a control unit and added to filter transfer functions derived by a standard algorithm to determine corrected filter coefficients. Degenerate convergences calculating the transfer functions are avoided.

Abstract: A method for data processing in an optical network includes providing at least one main wavelength and processing a subcarrier modulation for the at least one main wavelength, wherein a portion of the subcarrier modulated signal is suppressed. An optical network component and a communication system having such an optical network component are also provided.

Abstract: A wavelength division multiplexer terminal with a multiplexer arrangement with a first switching matrix, and a demultiplexer arrangement with a second switching matrix allows flexibility for connection transceivers to ports of the wavelength division multiplexer and wavelength division demultiplexer respectively. Optical monitoring receivers are connected upstream the wavelength division multiplexer and downstream the wavelength division demultiplexer for managing and supervising connections.

Abstract: Bidirectional data signals are exchanged between a central unit and a plurality of network terminals. The optical carrier frequencies of the downstream and upstream signals are chosen so that reflections do not interfere with the selected signal at the optical network unit and not with the received upstream signals at the central unit. The optical network units select their associated downstream signal and generate an associated upstream signal.

Abstract: A subcarrier system generates a phase comparison signal in a transmitter and transmits the phase comparison signal together with an optical subcarrier multiplex signal in the same transmission channel of an optical network. A receiver measures a phase distortion between a phase reference signal and the received phase comparison signal for each modulation section of the received subcarrier symbols, calculating at least one correction value and correcting time jitters or phase impairments of all parallel received or regained subcarrier symbols as a function of the phase distortion of the received phase comparison signal. Time jitter/phase jitter can be compensated without high hardware expenses.