Abstract:
The reception(102) reception unit includes; a first processing unit processing a first signal received from a source channel, and including a filtering unit to filter said first signal in digital domain, and extract unit to extract a information from said first signal; a second processing unit processing a second signal received from a destination channel, and said source channel and said destination channel are distinct each other; a third processing unit providing said information extracted from said first signal to said second signal said third processing unit executes; providing said information from said first processing unit to said second processing unit using information lanes of a clock rate strictly lower than a symbol rate of said second signal, a monitoring unit to generate a monitor signal according to the quality of said second signal; and a control unit controlling a skew between said first signal and said second signal in a bandwidth of said filtering units in said first processing unit.
Abstract:
O presente invento diz respeito a um método de equalização não-linear do canal óptico no domínio da frequência em sistemas de comunicação ótica de longo alcance e elevado débito que se baseia numa função de transferência inversa de Volterra, para mitigação das distorções do sinal em sistemas de comunicações ópticos. É caracterizado por: se extrair do sinal ótico recebido a informação de fase e amplitude; as componentes do sinal serem digitalizadas em dispositivos de conversão analógico- igital; o sinal digitalizado alimentar uma unidade física de processamento digital de sinal.
Abstract:
Disclosed is a receiver for receiving an optical signal comprising a plurality of carriers within a predetermined frequency band. The receiver comprises means for sampling and converting each of the carriers into a set of corresponding digital signals, and a digital processing unit for processing said digital signals of said set of digital signals such as to mitigate transmission impairments of the corresponding optical carriers based on corresponding processing parameters. The digital processing unit is configured for determining such processing parameters by carrying out a corresponding parameter derivation procedure based on one of the digital signals of said set of digital signals. The processing unit is configured for sharing thus determined processing parameters for processing of other digital signals among said set of digital signals based on said shared determined processing parameters, or processing parameters derived from said shared determined processing parameters.
Abstract:
A nonlinearity compensation technique for a CO-OFDM transmission system in which a proportion (e.g. up to 50%) of OFDM subcarriers is transmitted along with a phase-conjugate copy (PCP) on another subcarrier (replacing a data carrying subcarrier) to enable nonlinear distortion compensation. Nonlinear distortion experienced by closely spaced subcarriers in an OFDM system is highly correlated. The PCPs are used at the receiver to estimate the nonlinear distortion (e.g. nonlinear phase shift) of their respective original subcarriers and other subcarriers close to the PCP. With this technique, the optical fibre nonlinearity due to the Kerr effect in OFDM systems can be effectively compensated without the complexity of DBP or 50% loss in capacity of the phase conjugate twin wave (PC-TW) technique. Moreover, the technique proposed herein can be effectively implemented in both single polarization and PMD systems, in both single channel and WDM systems.
Abstract:
Technology for fiber parameter identification in an optical communications network (100) is described. One or more C-matrices are calculated from one or more corresponding signals received at a receiver (106) from a transmitter (104) over a link (102) in the network (100), each C-matrix comprising a plurality of C-coefficients representative of nonlinear noise in the received signal from which the C-matrix is calculated. For each of the received signals, a different amount of chromatic dispersion 'CD' pre-compensation is applied at the transmitter (104). The C-matrices are used to identify one or more fiber parameter estimates of the link (102), such as one or more fiber types, one or more nonlinear coefficients, or one or more dispersion coefficients. A controller (108) of the network (100) may use the identified fiber parameters estimates to control a state of the network (100) to achieve an objective, such as improved network performance.