Provided is an apparatus for measuring a filtering characteristic, a pre-equalizer and an optical communication equipment where the apparatus includes: a first processing unit configured to determine a filtering characteristic of a receiving end, or determine a joint response of a filtering characteristic of a transmitting end and the filtering characteristic of the receiving end, in a spectrum of a receiving signal obtained after a first measurement signal and a second measurement signal pass through respective filtering modules, according to a nonoverlapped spectral part of the first measurement signal and the second measurement signal. The filtering modules through which the first measurement signal passes include a transmitting end filtering module and a receiving end filtering module, the filtering module through which the second measurement signal passes include the receiving end filtering module.

A method and apparatus for measuring a filtering characteristic, pre-equalizer and communication equipment. The method includes: obtaining a receiving signal after two measurement signals of different spectral ranges pass through different filtering modules and are received at the same time at a receiving end; and determining a part of a filtering characteristic of a receiving end and a part of a joint response according to a nonoverlapped spectral part of the two signals in the spectrum of the receiving signal.

An optical receiver includes a dividing unit, a control unit, and a compensating unit. The dividing unit divides an optical transmission signal into a plurality of frequency components by a set number of divisions and a set division bandwidth. The control unit controls the number of divisions and the division bandwidth on the basis of transmission path information about an optical transmission line through which the optical transmission signal is transmitted and signal information about the optical transmission signal. The compensating unit compensates optical nonlinear distortion of each of the frequency components divided by the dividing unit.

A transimpedance amplifier includes a first and a second power supply terminal for receiving a positive constant supply voltage, wherein the second power supply terminal represents a ground, and an input terminal adapted to be connected to a current source. The transimpedance amplifier further comprises a transistor comprising a control terminal and two further terminals, wherein the input terminal is connected to the control terminal of the first transistor. An inductor is connected between the first of the two further terminals of the transistor and the first power supply terminal, and a bias network is connected between the second of the two further terminals of the transistor and ground. Specifically, the transimpedance amplifier is configured such that the resistance between said first of said two further terminals of said first transistor and said first power supply terminal is small enough, such that said transimpedance amplifier operates as a differentiator.

Optimization systems and methods are described configured to optimize filter coefficients in pulse shaping filters in transmitters and matched filters in receivers to maximize Q-factor in a fiber optic system. The systems and methods include receiving a measured Q-factor for one or more channels; iteratively adjusting filter coefficients of the pulse shaping filters and the matched filters to maximize a measured Q-factor of a channel of the one or more channels; and setting the filter coefficients of the pulse shaping filters and the matched filters to optimized values based on the iteratively adjusting.

A transimpedance amplifier includes a first and a second power supply terminal for receiving a positive constant supply voltage, wherein the second power supply terminal represents a ground, and an input terminal adapted to be connected to a current source. The transimpedance amplifier further comprises a transistor comprising a control terminal and two further terminals, wherein the input terminal is connected to the control terminal of the first transistor. An inductor is connected between the first of the two further terminals of the transistor and the first power supply terminal, and a bias network is connected between the second of the two further terminals of the transistor and ground. Specifically, the transimpedance amplifier is configured such that the resistance between said first of said two further terminals of said first transistor and said first power supply terminal is small enough, such that said transimpedance amplifier operates as a differentiator.

A receiver applies a calibration method to compensate for skew between input channels. The receiver skew is estimated by observing the coefficients of an adaptive equalizer which adjusts the coefficients based on time-varying properties of the multi-channel input signal. The receiver skew is compensated by programming the phase of the sampling clocks for the different channels. Furthermore, during real-time operation of the receiver, channel diagnostics is performed to automatically estimate differential group delay and/or other channel characteristics based on the equalizer coefficients using a frequency averaging or polarization averaging approach. Framer information can furthermore be utilized to estimate differential group delay that is an integer multiple of the symbol rate. Additionally, a DSP reset may be performed when substantial signal degradation is detected based on the channel diagnostics information.

Disclosed are an apparatus and method configured to process video data signals operating on a passive optical network (PON). One example method of operation may include receiving a data signal at an optical distribution network node (ODN) and identifying signal interference in the data signal. The method may also include modifying a shape of the data signal in the electrical domain and transmitting the modified data signal to at least one optical termination unit (ONT).

A method (10) of non-linear propagation impairment equalisation, the method comprising the steps of: a. receiving (12) communications traffic carried by an optical communications signal transmitted over an optical communications link; b. generating (14) a time dependent filter representation of a nonlinear time-variant impulse response of the inverse of the optical communications link; and c. applying (16) the time dependent filter representation to the received communications traffic to form non-linear propagation impairment equalised communications traffic. An optical communications link nonlinear propagation impairment equaliser and optical communications signal receiver apparatus are also provided.

A network element comprises a light source generating an optical signal having a USP with a USP bandwidth, an ASE source generating ASE noise, a WSS partitioning the ASE noise into a series of ASE passbands comprising a default bandwidth, an allocated start frequency, and an allocated end frequency, a processor and a memory storing a band layout map having a current start frequency and a current end frequency for each ASE passband and comprising a unique deterministic layout of the ASE passbands, and instructions to: receive a USP operation; identify one or more ASE passbands impacted by the USP based on the band layout map and generate a bandwidth tracker comprising tracking attributes for the identified ASE passbands; adjust the tracking attributes for the identified ASE passbands based on the USP operation; and generate resize intent instructions for the identified ASE passbands based on the bandwidth tracker.