Methods and systems for a narrowband, non-linear optoelectronic receiver are disclosed and may include amplifying a received signal, limiting a bandwidth of the received signal, and restoring the signal utilizing a level restorer, which may include a non-return to zero (NRZ) level restorer. The NRZ level restorer may include a pulse-triggered bistable circuit, which may include two parallel inverters, with one being a feedback path for the other. The inverters may be single-ended or differential. A photogenerated signal may be amplified in the receiver utilizing a transimpedance amplifier and programmable gain amplifiers (PGAs). A received electrical signal may be amplified via PGAs. The bandwidth of the received signal may be limited utilizing one or more of: a low pass filter, a bandpass filter, a high pass filter, a differentiator, or a series capacitance on the chip. The signal may be received from a photodiode integrated on the chip.

Embodiments of the present invention provide a signal receiving method and a receiver. The signal receiving method includes: sequentially preprocessing a received first signal to obtain to-be-processed second signals; generating filtering coefficients for the second signals by converting colored noise of the second signals into white noise; and filtering the corresponding second signals according to the filtering coefficients. Filtering can be performed according to different channel conditions and transmission requirements, thereby improving system performance of the receiver.

One or more operational parameters associated with pluggable optical transceivers are estimated to mitigate impairments to an optical signal caused by imperfections in the optical transceivers. A monitoring algorithm within a receiver signal processor may further use the estimated operational parameters associated with the pluggable optical transceivers to determine whether the transceivers are performing correctly. If the monitoring algorithm determines that either the transmitting or receiving optical transceiver is not functioning correctly, it may generate an alarm signal to notify a system administrator about the damaged device.

One or more operational parameters associated with pluggable optical transceivers are estimated to mitigate impairments to an optical signal caused by imperfections in the optical transceivers. A monitoring algorithm within a receiver signal processor may further use the estimated operational parameters associated with the pluggable optical transceivers to determine whether the transceivers are performing correctly. If the monitoring algorithm determines that either the transmitting or receiving optical transceiver is not functioning correctly, it may generate an alarm signal to notify a system administrator about the damaged device.

A light receiving device that includes a lens that collects a spatial light signal, a sensor array including a plurality of light receivers that receives the spatial light signal collected by the lens, and a reception unit that integrates an electric signal derived from the spatial light signal received by each of the plurality of light receivers and selects a light receiver that receives the spatial light signal. according to a voltage value of the integrated electric signal.

Methods and apparatus for interference cancelation in a radio frequency communications device are described. In various embodiments a signal to be transmitted in converted into an optical signal and processed using an optical filter assembly including one or more optical filters to generate an optical interference cancelation signal. The optical interference cancelation signal is converted into an analog radio frequency interference cancelation signal using an optical to electrical converter prior to the analog radio frequency interference cancelation signal being combined with a received signal to cancel interference, e.g., self interference. The optical filter assembly can include a large number of taps, e.g., 30, 50, 100 or more. Each tap may be implemented as a separate optical filter or series of optical filters. Delays and/or gain of the optical filters can be controlled dynamically based on channel estimates which may change due to changes in the environment and/or communications device position.

An audio signal transmission device, an audio signal transmission method, an audio signal reception device, an audio signal reception method, and an audio system are provided. The audio signal transmission method includes: receiving an audio signal and generating a low-noise buffer signal by a low-noise buffer element; converting the low-noise buffer signal into a digital signal by an analog-to-digital conversion element; serializing a digital signal to output one or more serialized digital signals by a serializer element; and converting the one or more the serialized digital signals into one or more optical signals by an optical interface transmission device. The audio signal reception method includes: receiving and converting one of the at least one optical signal and outputting an electrical signal by the optical interface reception device; and deserializing the electrical signal and outputting the deserialized digital signal by the deserializer element.

Embodiments of the present invention provide a signal receiving method and a receiver. The signal receiving method includes: sequentially preprocessing a received first signal to obtain to-be-processed second signals; generating filtering coefficients for the second signals by converting colored noise of the second signals into white noise; and filtering the corresponding second signals according to the filtering coefficients. Filtering can be performed according to different channel conditions and transmission requirements, thereby improving system performance of the receiver.

A method decodes an optical signal transmitted over an optical channel from a transmitter to a receiver. The receiver receives the transmitted optical signal to produce a digital signal including data symbols and pilot symbols, and determines filtering coefficients based on an error between amplitudes of the received pilot symbols and amplitudes of transmitted pilot symbols, while ignoring errors between phases of the received pilot symbols and phases of the transmitted pilot symbols. The amplitudes and the phases of the transmitted pilot symbols are known at the transmitter and the receiver. The receiver filters the digital signal according to the filtering coefficients to produce a filtered signal with equalized amplitude and an unconstrained phase demodulates and decodes the filtered signal to produce an estimate of the transmitted optical signal.

An optical transceiver includes a printed circuit board, a transceiver module, a plurality of filtering capacitors and a noise absorber. The printed circuit board is provided with a plurality of signal lines and a plurality of gold fingers each connecting one of the plurality of signal lines. The transceiver module is disposed on the printed circuit board and connecting the plurality of signal lines. Each of the plurality of filtering capacitors is located on one of the plurality of signal lines. The noise absorber covers at least one surface of the plurality of filtering capacitors opposite to the printed circuit board.