An asymmetric bidirectional optical wireless communication system based on orbital angular momentum comprises a system end device and a client end device. The system can split light into P-polarization beam and S-polarization beam, and utilize the orbital angular momentum multiplexing technology to increase the system capacity for uplink transmission in the client end device. In addition, the system also uses the combination of a beam homogenizer and a spatial light modulator to design an orbital angular momentum multiplexer with low energy loss, which can increase the number of orbital angular momentum channels by increasing the effective area of the components.

A system comprises a transmitter that generates a combined signal including a first group of optical signals and a second group of optical signals, the first group of optical signals comprising M+X number of optical signals in a first polarization mode, the second group of optical signals comprising N number of optical signals in a second polarization mode, wherein the number of N and M optical signals comprise payload signals, where the X number of optical signals comprises at least one first pilot signal. The system may further include a receiver comprising a polarization recovery device that receives the combined signal and that recovers, from the combined signal, the first group of optical signals with the first polarization mode and the second group optical signals with the second polarization mode based on feedback indicative of at least one signal characteristic of the at least one first pilot signal.

A system comprises a transmitter that generates a combined signal including a first group of optical signals and a second group of optical signals, the first group of optical signals comprising M+X number of optical signals in a first polarization mode, the second group of optical signals comprising N number of optical signals in a second polarization mode, wherein the number of N and M optical signals comprise payload signals, where the X number of optical signals comprises at least one first pilot signal. The system may further include a receiver comprising a polarization recovery device that receives the combined signal and that recovers, from the combined signal, the first group of optical signals with the first polarization mode and the second group optical signals with the second polarization mode based on feedback indicative of at least one signal characteristic of the at least one first pilot signal.

The present application relates to devices and components including apparatus, systems, and methods for high-throughput, low-power signaling.

In order to reduce the amount of calculation for signal distortion compensation, this filter coefficient updating device for updating the filter coefficients of a plurality of filters in a filter layer comprising the plurality of filters, which are connected in a first plurality of stages with respect to received data, is provided with: a deriving unit for deriving the respective filter coefficients of the plurality of filters in one or a plurality of stages included in the first plurality of stages, by means of output data output from the last stage of the first plurality of stages; and an updating unit for updating each of the filter coefficients.

A communication network includes a coherent optics transmitter, a coherent optics receiver, an optical transport medium operably coupling the coherent optics transmitter to the coherent optics receiver, and a coherent optics interface. The coherent optics interface includes a lineside interface portion, a clientside interface portion, and a control interface portion.

A communication network includes a coherent optics transmitter, a coherent optics receiver, an optical transport medium operably coupling the coherent optics transmitter to the coherent optics receiver, and a coherent optics interface. The coherent optics interface includes a lineside interface portion, a clientside interface portion, and a control interface portion.

An optical transmission apparatus (1_1) according to the present invention includes a first transmission unit (11_1) that transmits a first optical transmission signal (21_1), a second transmission unit (11_2) that transmits a second optical transmission signal (21_2), and an output unit that outputs, when the first optical transmission signal (21_1) and the second optical transmission signal (21_2) share a set of information, both the first optical transmission signal (21_1) and the second optical transmission signal (21_2) to a first path (26_1) and outputs, when the first optical transmission signal (21_1) and the second optical transmission signal (21_2) do not share the set of information, one of the first optical transmission signal (21_1) and the second optical transmission signal (21_2) to a second path (26_2).

In order to estimate a polarization fluctuation speed with high accuracy independently of the quality of a received signal, a polarization-fluctuation estimating device according to the present invention includes: a polarization de-multiplexing unit that generates a single-polarization optical signal from an input polarization-multiplexed optical signal; a photoelectric converting unit that converts the generated optical signal into an electrical signal; and an estimation unit that estimates the polarization fluctuation speed of the polarization-multiplexed optical signal in accordance with the electrical signal.

In order to estimate a polarization fluctuation speed with high accuracy independently of the quality of a received signal, a polarization-fluctuation estimating device according to the present invention includes: a polarization de-multiplexing unit that generates a single-polarization optical signal from an input polarization-multiplexed optical signal; a photoelectric converting unit that converts the generated optical signal into an electrical signal; and an estimation unit that estimates the polarization fluctuation speed of the polarization-multiplexed optical signal in accordance with the electrical signal.