Telefonaktiebolaget Lm Ericsson (Publ)

Tommaso Catuogno

Fabio Cavaliere

Luca Poti

Giulio Bottari

Luca Giorgi

Robert Frank Brunner

Enrico Forestieri

Marco Secondini

David V Plant

Francesco Fresi

Ramon Gutierrez Castrejon

Saber Md Ghulam

Menelaos Ralli

Methods in an optical receiver, for decoding a received M-level pulse-amplitude-modulated, PAM-M, optical signal. An example method comprises, for a first interval, decoding () the received PAM-M optical signal using a standard PAM-M decoder with M-1 thresholds, using first sampling times, to obtain a first set of decoded bits, and decoding () the received PAM-M optical signal using a duobinary decoder with 2M-2 thresholds, at second sampling times offset from the first sampling times, to obtain second set of decoded bits. The method further comprises calculating () first and second error metrics corresponding to the first and second sets of decoded bits, respectively, and selecting () the standard PAM-M decoder or the duobinary decoder for subsequent decoding of the received PAM-M optical signal, based on the first and second error metrics.

Chromatic dispersion tolerant PAM-M transceiver for optical routing to extended paths

A method () of encoding communications traffic bits onto an optical carrier signal in a pulse amplitude modulation, PAM, format. The method comprises: receiving () bits to be transmitted; receiving () an optical carrier signal comprising optical pulses having an amplitude and respective phases; performing () PAM of the optical pulses to encode at least one respective bit in one of a pre-set plurality of amplitudes of a said optical pulse; and performing () phase modulation of the optical pulses to encode at least one further respective bit in a phase difference between a said optical pulse and a consecutive optical pulse.

Encoding and decoding communications traffic in a pulse amplitude modulation format and optical apparatus for same

A path computation engine, PCE, () for an optical communications network comprising a plurality of nodes and a plurality of links. The PCE comprises a processor and memory comprising instructions executable by the processor whereby the PCE is operative to: receive a request to configure a quantum key, Qkey, path from a first node to a second node in the optical communications network for a quantum key distribution, QKD, signal for a quantum key for a secure data transmission signal; calculate a feasible Qkey path from the first node to the second node that is logically different to a traffic path from the first node to the second node for the secure data transmission signal, wherein the Qkey path is feasible if an optical signal power originating from the secure data transmission signal within the Qkey path, caused by optical interference of the secure data transmission signal with the QKD signal, is below a predetermined threshold value; and generate a control signal comprising instructions arranged to configure said feasible Qkey path.

Path computation engine and method of configuring an optical path for quantum key distribution

A receiver module () is disclosed for receiving an optical input signal and generating an electrical output signal from the optical input signal. The receiver module comprises an input () for receiving an optical input signal and a polarising beam splitter () for splitting one of the optical input signal and a local recovery optical signal. The receiver module also comprises a multiport optical coupler () for coupling the outputs of the polarisation beam splitter and the other of the optical input signal and local recovery optical signal and outputting a plurality of outputs. The receiver module further comprises a first photodetector unit () for individually photodetecting the outputs of the multiport optical coupler and an optical modulation unit () for using each of the photodetected outputs to modulate a respective local conversion optical signal, where each local conversion optical signal has a different frequency from the other local conversion optical signals. The receiver module also comprises an optical coupler () for coupling the modulated local conversion optical signals to generate an optical output signal and a second photodetector unit () for photodetecting the optical output signal to generate an electrical output signal. Also disclosed are a method () and a multichannel receiver ().

Optical receiver and method of operation

Growing community of inventors

Pisa, Italy

Tommaso Catuogno