Systems, methods, and apparatuses for wireless communication are described. Input data for in-phase branch/quadrature branch (I/Q) imbalance or mismatch may be compensated for or non-linear power amplifier noise may be used to generate compensated input data. In some examples, a transmitter may be configured to transmit communications signaling via a first antenna, the transmitter including a filter configured for digital mismatch correction; a receiver may be configured to receive communications signaling via a second antenna; and a switch may be configured to selectively activate a first switch path to couple the transmitter and the first antenna and a second switch path to couple the receiver and the transmitter to provide communications signaling received via the transmitter as feedback for the filter through the receiver.

This document discloses a solution for detecting interference in a radio access network. According to an aspect, a method includes as performed by a network node of the radio access network: acquiring a first equalized signal representing a signal received by a first radio head serving a terminal device, the first equalized signal including a signal received by the first radio head from the terminal device; acquiring a second equalized signal representing a signal received by a second radio head not serving the terminal device, wherein the second radio head is spatially distant from the first radio head; cross-correlating the first equalized signal with the second equalized signal and determining, on the basis of said cross-correlating, whether or not the second equalized signal also includes a signal received from the terminal device; and as a result of the second equalized signal being determined to include the signal received from the terminal device, causing execution of an interference management action.

A low power receiver having a feedforward equalization, FFE, based continuous time linear equalizer, CTLE. The FFE CTLE comprises: an input for receiving an input signal; a main first path operably coupled to the input and comprising a source-follower transistor arranged to apply a scaling factor to the received input signal; a second path operably coupled to the input and comprising a delay arranged to apply a delay to the received input signal and a common source transistor common source transistor arranged to apply a scaling factor to the received delayed input signal, wherein the source-follower transistor and the common source, CS, transistor are connected as a single SF-CS stage whose output is arranged to subtract the output of the common source transistor from an output of the source-follower transistor.

A signal estimation apparatus classifies reception signal components included in a reception signal y and transmission signal components included in a transmission signal into a plurality of signal groups in accordance with a degree of a correlation between the reception signal component and the transmission signal component, on the basis of system information, sets, for each signal group, parameters β, ρ, τ and η that specifies a detail of a signal estimation method to be either one of a learned value that is learnable by a learning operation and a fixed value that is independent from the learning operation, and estimates, for each signal group, an estimation signal xe that is an estimated value of the transmission signal from the reception signal by using the signal estimation method specified by the set parameter.

A hybrid electrical and optic system-on-chip (SOC) device configured for both electrical and optic communication includes a substrate, an electrical device configured for electrical communication arranged on the substrate, a photonics device configured for optic communication arranged on the substrate, and a self-test module arranged on the substrate. The self-test module is configured to receive a loop-back signal indicative of an optical signal output from the photonics device and calibrate the photonics device based on the loop-back signal.

A wireless telecommunications system that mitigates infrasymbol interference due to Doppler-shift and multipath and enables multiple access in one radio channel. Embodiments of the present invention are particularly advantageous for wireless telecommunications systems that operate in high-mobility environments, including high-speed trains and airplanes.

The present disclosure provides a multi-carrier time-division multiplexing (MC-TDMA) modulation and demodulation method and system. Before multi-carrier modulation is performed on an input symbol, an interleaving allocation and an FFT may be performed, a time domain symbol may be transformed into a frequency domain symbol signal to perform a MDFT treatment. A sending end may adopt an analyzing filter bank structure, and pre-filtering and an IFFT may be performed on a signal successively. A pre-filter may be positioned between an NM point FFT and an M point IFFT, a PAPR value of the system may be reduced using the symmetry of a coefficient of a filter, and a frequency domain symbol signal may be allocated to different sub-bands for multi-carrier modulation.

A communication device communicates a radio frame including a preamble and a data field of a physical layer (PHY). The preamble includes an L-STF (Legacy Short Training Field), an L-LTF (Legacy Long Training Field), an L-SIG (Legacy Signal Field), an EHT-SIG-A (Extremely High Throughput Signal A Field), an EHT-STF, and an EHT-LTF, and the EHT-SIG-A includes a field indicating a standard that the radio frame complies with.

A system and method for mitigating nonlinearity in an optical communication link with multiple carriers uses mutual frequency referencing to stabilize at least a portion of the multiple carriers. Using at least one frequency-referenced signal, carrier nonlinearity can be determined and compensated within the link by pre-distortion, back-propagation, or a combination of both. Mutual frequency referencing may be performed at the emitting end of the link, at the receiving end, or a combination of both.

A training packet sending method and apparatus, where the method includes generating, by a first device, a training packet, where the training packet includes a preamble, a header, and a training field, and the header includes at least a legacy header, and repeatedly sending, by the first device, the preamble using N channels, sending the legacy header in the header using the N channels, and sending the training field to at least one second device using H channels of the N channels, where N is greater than 1, and H is greater than 1 and less than or equal to N.