An optical amplifier includes: an amplification section includes a plurality of routes; a determination section that selects a passage route, through which the multi-wavelength optical signal passes, among the plurality of routes; an input-side detector that detects input power of the multi-wavelength optical signal input to the amplification section; a variable optical attenuator that attenuates the multi-wavelength optical signal that is amplified through passing through the passage route determined by the determination section; an output-side detector that detects output power of the multi-wavelength optical signal attenuated by the variable optical attenuator; a controller that controls the amplification section based on the input power detected by the input-side detector and the output power detected by the output-side detector such that a gain of the amplification section is steady; and an adjuster that adjusts an attenuation of the variable optical attenuator in accordance with the input power detected by the input-side detector.

The present disclosure relates to beam training methods and communication apparatuses. In one example method, a first UE sends first control information by using a first transmission beam, where the first control information includes resource location information of a first resource. Then, the first UE sends a first reference signal on the first resource by using M transmission beams, where M is a positive integer, the first transmission beam is different from each of the M transmission beams, and the first transmission beam covers each of the M transmission beams.

Methods, systems, and devices for wireless communications are described. For instance, a wireless device may measure a first portion of a cyclic prefix (CP) of a wireless transmission received using a first subset of a set of analog receive elements. The wireless device may measure a second portion of the CP of the wireless transmission using a second subset of the set of analog receive elements. The wireless device may determine a beam gain for the set of analog receive elements based on measuring the first portion of the CP received using the first subset and the second portion of the CP received using the second subset. In some examples, measuring using the first subset and the second subset may be associated with improved automatic gain control performance and/or transmission power control as compared to measuring with each of a set of analog receive elements.

Methods, apparatuses, and systems for transmitting information between nodes in a point-to-point wireless communication network is disclosed. One method includes constructing, by a sector of a transmitting node, a packet including data that is to be transmitted to a receiving node in the wireless network, wherein the constructed packet includes a short training field, a channel estimation field, a header field, and a data payload, and transmitting by the sector of the transmitting node, a jamming code before the short training field of the constructed packet, thereby reducing a likelihood that the receiving node will decode a different short training field of an interfering packet before the receiving node decodes the short training field of the constructed packet.

A gain adjustment method in an optical transmission system that performs communication by a digital coherent system including an optical transmission device and an optical reception device includes converting an optical signal transmitted from the optical transmission device into an electrical signal, converting the electrical signal from an analog signal to a digital signal, performing first signal processing on the digital signal, performing adaptive equalization processing on the digital signal subjected to the first signal processing using a digital filter, correcting an amplitude of an output signal of the digital filter based on information of the amplitude and a phase of the output signal of the digital filter and the amplitude of a known transmission signal, and performing second signal processing on the output signal of the digital filter whose amplitude has been corrected.

Optical networks, network elements, and methods of use are described herein, including a network element comprising a processor; and a non-transitory computer readable memory storing instructions that, when executed by the processor, cause the processor to: receive, from a headend network element, instructions to collect a QoS baseline measurement indicative of performance of optical carrier(s) on a transmission line, collect the QoS baseline measurement; collect a QoS current measurement of the QoS data, after a first spectral loading operation is performed on the transmission line segment by the headend network element; determine that a numerical difference between the QoS current measurement and the QoS baseline measurement is outside of a predetermined threshold; and send instructions to the headend network element to abort a second spectral loading operation for the transmission line segment and to execute an AGC cycle to adjust amplifier operating conditions.

Spectrum control systems and methods are implemented to minimize power spectral density (PSD) offsets by adjusting gain of optical amplifiers in an optical section. The optical section is a logical boundary from one optical signal access point to a next adjacent optical signal access point. The systems and methods include estimating PSD offset from a given target for a peak channel at each span in the optical section, wherein the estimated PSD offset is divided at each span into two components including a self-introduced offset and an uncompensated offset from upstream; generating, for each span, a separate controller response for the self-introduced offset and the uncompensated offset from upstream; and controlling the gain of the optical amplifiers based on the separate controller response for the self-introduced offset and the uncompensated offset from upstream, for each span.

An optical amplifier that amplifies an incident WDM signal and includes cores having an amplification medium, the optical amplifier includes: a wavelength demultiplexer configured to demultiplex the incident WDM signal into wavelength bands and introducing the demultiplexed WDM signals into the cores separately; a wavelength multiplexer configured to multiplex amplified optical signals propagated through the cores and outputting the multiplexed signal; and an wavelength demultiplexing controller configured to monitor an amplification rate of a specific wavelength band of an amplified WDM signal or a scale associated with an amplification rate of a specific wavelength band, demultiplexing, from the incident WDM signal, an optical signal of a wavelength band having relatively-small optical amplification efficiency according to a monitoring result, and controlling demultiplexing performed by the wavelength demultiplexer in such a way as to amplify, with a relatively-large amplification rate, the optical signal of the wavelength band having relatively-small optical amplification efficiency.

Disclosed is a method by which a terminal transmits a signal in a wireless communication system. The terminal can receive configuration information for setting a first subcarrier spacing (SCS) for a plurality of slots, and transmit a physical sidelink shared channel (PSSCH) in the plurality of slots. At this time, if the terminal coexists with a legacy terminal in a co-channel and the plurality of slots fully overlap a legacy subframe of the legacy terminal, second transmission power in at least one slot that excludes a first slot from among the plurality of slots can be limited by means of first transmission power of the first slot.

Examples described herein relate to a receiver training method. To configure a static gain for at least one static gain amplifier and a target amplitude for a dynamic gain amplifier, a dynamic gain adjustment is disabled and the dynamic gain amplifier is configured to apply a predetermined fixed gain to the static gain amplified signal to generate a test signal. Furthermore, an effective static gain magnitude for at least one static gain amplifier and an effective amplitude for the test signal are determined based on a link performance metric. The static gain is set to the effective static gain magnitude, and a target amplitude for the dynamic gain amplifier is set to the effective amplitude. Then, the dynamic gain adjustment may be enabled to maintain an amplitude of a dynamic gain amplified signal at an output of the dynamic gain amplifier at the target amplitude by varying the dynamic gain.