32 results about "Error vector magnitude" patented technology

A system and method for determining an error vector magnitude (EVM) of a polarized transmission from a device-under-test (DUT). A first signal transmitted by the DUT is received via a horizontally polarized receiver antenna, and a second signal transmitted by the DUT is received via a vertically polarized receiver antenna. The second signal is coherent with the first signal. The EVM is calculated based at least in part on the first signal and the second signal and a reference signal.

The invention discloses a radio frequency signal demodulation method and device. The method comprises the following steps: receiving an OFDM (Orthogonal Frequency Division Multiplexing)-based radio frequency signal comprising a plurality of subcarriers, each subcarrier time slot comprising a column of pilot signals; performing conversion processing on the radio frequency signal to obtain a frequency domain signal corresponding to each subcarrier, the frequency domain signal comprising a plurality of OFDM symbols; for each frequency domain signal, primary frequency offset compensation is carried out on each OFDM symbol in the frequency domain signal based on the pilot signal, and for a far-end OFDM symbol whose distance from the position of the pilot signal exceeds a preset distance, secondary frequency offset compensation is carried out on the far-end OFDM symbol based on the distribution state of each constellation point mapped to the constellation diagram; and recovering each frequency domain signal subjected to frequency offset compensation into original bit data. According to the method and the device, the technical problem that the error vector amplitude of a remote symbol demodulation result is relatively large when only a single-column pilot signal is configured in a subcarrier time slot in a traditional demodulation scheme is solved.

The application provides a method for controlling uplink throughput of a UAV satellite base station and the UAV satellite base station, and belongs to the technical field of communication. In the method for controlling uplink throughput of the UAV satellite base station, the UAV satellite base station analyzes modulation capability information sent by a UE, obtains a first modulation order and a second modulation order supported by the UE in different communication frequency bands, and combines a target communication frequency band currently located by the UE and a power switching type of the UE to perform optimized scheduling on a subsequent second uplink subframe, so that stable signal quality and throughput are maintained when the transmission power of the UE changes, the reduction of the throughput caused by the unstable error vector magnitude when the power switching is determined is effectively alleviated, the overall performance of the communication system is improved, and the waste of spectrum resources is reduced.

An apparatus includes a receiver configured to receive data, and circuitry configured to receive one or more symbols based at least on the data, determine, using the one or more symbols, an error vector magnitude (EVM) value, identify a quadrature amplitude modulation (QAM) size, determine, using the EVM value and the QAM size, a signal-to-noise (SNR) value, and adjust, based at least on the SNR value, a transmission rate of a transmitter.

An adaptable, multistage, multi-rate digital predistortion system that can increase the accuracy of the distortion applied to a power amplifier input signal is disclosed. Further, the digital predistortion system can be implemented using a reduced circuit area by reducing a number of coefficients used by the models applied to generate the distortion compensation signal. Further, the system can implement an improved digital predistortion adaptation engine that improves an adjacent channel leakage ratio of the digital predistortion system. Moreover, the system can compensate for non-linear impairments due to analog / RF circuits and systems and improve at least the following metrics: Error vector magnitude (EVM), adjacent channel leakage ratio (ACLR), spectrum emission mask (SEM), and power consumption of the circuits and systems. An example of circuits and systems is radio frequency power amplifier (RF PA).

An electronic device may include wireless circuitry with a baseband processor, a digital transmitter, a digital-to-analog-converter (DAC), and an antenna. The baseband processor may produce baseband signals. The digital transmitter may generate self-interference-compensated signals based on the baseband signals. The DAC may generate radio-frequency signals for transmission by the antenna based on the self-interference-compensated signals and square-wave local oscillator waveforms. The digital transmitter may include a self-interference canceller that generates the self-interference-compensated signals. The self-interference-compensated signals may mitigate the creation of self-interferer repetition replicas that land on the carrier frequency of the radio-frequency signals. This may allow the radio-frequency signals to be free from error vector magnitude degradation and spectral regrowth that would otherwise be produced due to self-interference in the radio-frequency signals output by the DAC.

A network node, such as a gNB, determines an adjacent channel leakage power ratio (ACLR) requirement relaxation for a UE and transmits, to the UE, first information of the ACLR requirement relaxation

A method for wireless communication at a user equipment (UE) and related apparatus are provided. In the method, the UE receives an indication of a requested value of an error vector magnitude (EVM) for a resampling process for an input signal from a network entity. The UE further processes the input signal using the resampling process and a set of parameters to obtain a processed signal. The set of parameters is based on the requested value of the EVM. The UE then communicates the processed signal with the network entity.

A radio frequency (RF) test device such as a spectrum analyzer may include an RF attenuator to attenuate a received RF signal; a mixer to down-convert the attenuated RF signal; an IF attenuator to attenuate the down-converted signal; an analog-to-digital converter (ADC) to digitize the attenuated, down-converted signal; and a processor, which may select attenuation values for one or more of the RF attenuator and the IF attenuator based on an error magnitude vector (EVM) analysis, an RF signal type, and a signal level at an input of the ADC. The processor may use a look-up table for the selection. Initial attenuation values may be selected based on an expected RF signal type, RF signal frequency, or RF signal bandwidth. The attenuation values may also be selected in an iterative manner stepping the attenuation values up or down.

The present invention relates to a system and method for monitoring multicore fibres (MCF). The system comprises a unit that generates the optical signal; a unit that processes and monitors this original signal; and the crosstalk and backscattering signals that are generated when the generated optical signal is transmitted through a fibre connecting two FIFOs. The method analyses these signals produced at different powers and determines a threshold defining a malfunction that switches off the laser in addition to transmitting radio signals over fibre without affecting data traffic quality, as assessed by the Error Vector Magnitude (EVM).

The invention relates to a system and method for estimating signal-to-noise ratio (SNR) and noise variance from error vector magnitude (EVM). In one embodiment, an apparatus includes a receiver configured to receive data; and circuitry configured to receive one or more symbols based at least on the data, determine an error vector magnitude (EVM) value using the one or more symbols, identify a quadrature amplitude modulation (QAM) size, determine a signal-to-noise ratio (SNR) value using the EVM value and the QAM size, and adjust a transmission rate of a transmitter based at least on the SNR value.

The application discloses a terahertz co-frequency interference characteristic evaluation method and system based on cross-domain mapping, relates to the technical field of terahertz wireless communication and electromagnetic compatibility, and solves the technical problems that link vulnerability is difficult to quantify and there is a lack of system-level correlation between radio frequency physical indicators and baseband demodulation performance in the prior art.The application collects power information of a receiving end under an interference-free injection and a co-frequency interference injection environment in a radio frequency power domain, calculates an interference signal ratio and a signal-to-interference-and-noise ratio, maps radio frequency power domain parameters to a modulation error ratio MER and an error vector magnitude EVM in a symbol decision domain, evaluates interference attenuation in combination with a spatial geometry variable in a spatial geometry domain, and comprehensively evaluates terahertz co-frequency interference characteristics by comprehensively considering radio frequency power domain indicators, symbol decision domain indicators and spatial geometry domain indicators.The application has good operability and reproducibility, and provides support for standardized testing, network deployment and safety boundary definition of a terahertz communication link.

The application relates to the field of satellite communication and discloses a satellite communication anti-interference transmission system, which comprises a phase rotation compensation module for removing Doppler frequency shift components; a channel state sensing unit for calculating an error vector magnitude variation gradient of pilot symbols; a transmission strategy control unit for generating a transmission reconstruction pulse when the variation gradient exceeds a slope threshold value; and a physical layer framing unit for truncating a physical layer long frame in response to the transmission reconstruction pulse, dividing residual service data into independent microframes, and reducing modulation order. The application uses a channel state variation gradient to capture interference energy injection characteristics, compresses a transmission strategy reconstruction response delay, effectively reduces data loss caused by transient error codes, and guarantees the physical continuity of a key data link in an electromagnetic countermeasure environment.

A method of error vector magnitude, EVM, minimization for a radio frequency, RF, measurement equipment is provided. The method comprises: measuring the EVM of a receive, RX, chain of the RF measurement equipment in accordance with a transmit, TX, feedback signal; and responsive to a trigger event, actuating one or more power-adjusting members interposed in the RX chain in accordance with the measured EVM of the RX chain. Among others, the RF measurement equipment is thereby consistently operated based on optimal power levels in the RX chain.

Apparatuses and methods for negotiation and signaling for cooperative control of power amplifier nonlinearity are disclosed. At least some example embodiments may allow signaling to support the design and deployment of cooperative control of power amplifier nonlinearity for digital pre-distortion (DPD) applications in user equipment and digital post-distortion (DPoD) applications in network nodes, where digital pre-distortion may be used to control out-of-band transmissions (e.g., adjacent channel leakage ratio (ACLR)), and digital post-distortion (DPoD) applications in network nodes. And digital post-distortion may be used to control in-band transmission (e.g., error vector magnitude (EVM)).

The embodiment of the invention provides an IQ imbalance calibration method and device, a signal transmitter and a zero intermediate frequency transceiver, and the method comprises the steps: obtaining a reference baseband signal and a radio frequency signal outputted by an IQ modulation channel based on the reference baseband signal, and converting the radio frequency signal into a modulation baseband signal; reconstructing the modulation baseband signal to generate a baseband feedback signal used for representing distortion of the IQ modulation channel; based on the reference baseband signal and the baseband feedback signal, obtaining a pre-distortion parameter for compensating IQ imbalance; performing pre-distortion processing on the reference baseband signal by using the pre-distortion parameter to generate a baseband pre-distortion signal; and based on the baseband pre-distortion signal, performing imbalance calibration on an IQ modulation channel. As the IQ modulation channel is calibrated, the image rejection ratio and error vector amplitude performance of the output signal can be improved, and the calibration precision of the IQ modulation channel is improved.

Methods, systems, and devices for wireless communications are described. Generally, the described techniques may enable a transmitting device to transmit signals in accordance with an error vector magnitude (EVM) value that is based on the modulation order and the shaping rate of the signals. For example, the transmitting device may transmit the signals according to a modulation coding shaping scheme (MCSS). In some cases, the EVM value may further be based on the coding rate and spectral efficiency of the signals. In some examples, a user equipment may report its capability of a modulation order with probabilistic shaping, without probabilistic shaping, and a supported shaping rate. In response to the capability report, a network entity may configure MCSS entries of an MCSS table. For example, the UE may receive a subset of entries of an MCSS table and transmit signals in accordance with an entry of the MCSS table.

Group delay determination in a communication circuit is disclosed. The communication circuit includes a power amplifier circuit that amplifies a radio frequency (RF) signal based on a modulated voltage and a power management integrated circuit (PMIC) that generates the modulated voltage. Herein, the PMIC includes a group delay determination circuit to determine a relative group delay between the modulated voltage and a modulated current, which is internal to the power amplifier circuit and unknown to the PMIC, solely based on signals known to the PMIC. The determined relative group delay can help to time align the modulated voltage with the modulated current at the power amplifier circuit to improve error vector magnitude (EVM) and / or adjacent channel leakage ratio (ACLR). Further, by determining the relative group delay based on known signals to the PMIC, it is possible to achieve good time alignment between the modulated voltage and the modulated current.

The invention discloses an optical performance monitoring method, device and equipment, a vehicle, a medium and a program product, and belongs to the technical field of optical fiber communication. The method comprises: acquiring a target signal of an optical network; the target signal comprises a signal of the optical network in at least part of monitoring duration of a monitoring period; and determining the signal quality of the optical network in the monitoring period of the target signal according to the error vector amplitude of the target signal. According to the embodiment of the invention, the signal of the optical network in at least part of the monitoring duration of the monitoring period is acquired, the part of signal represents a part of signal of the monitoring period instead of the signal of the whole monitoring period, and the signal quality of the monitoring period is determined through the error vector amplitude of the part of signal. The signal quality of the monitoring period is estimated through the short signal sequence, a large number of data points of the signals of the whole monitoring period do not need to be calculated, the optical performance monitoring efficiency is improved, and therefore the optical performance monitoring method and device can better adapt to the rapidly-changing network environment.

According to an example aspect of the present invention, there is provided an apparatus in a user equipment configured to receive, from a network node, a first information of an error vector magnitude, EVM, target allowed for the apparatus; adjust one or more digital predistortion, DPD, settings based at least in part on the received first information of the EVM target allowed for the apparatus; and transmit, to the network node, at least one signal at an EVM level based at least in part on the adjusted DPD settings.

The invention provides an anti-noise high-precision error vector amplitude measurement system and method for a satellite launching system. The system comprises a demodulator, an A / D conversion circuit, a data distributor, a decoding function module and an EVM processing module. And the demodulator carries out carrier synchronization, code synchronization and blind equalization processing on the digital signal, and outputs real I-path data Ireal and Q-path data Qreal. The data distributor copies the Ireal and the Qreal and divides the Ireal and the Qreal into two paths for output, one path is transmitted to the decoding function module, and the other path is transmitted to the EVM processing module. And the EVM processing module comprises a phase error calculation unit, an amplitude error calculation unit and an error vector amplitude calculation unit which are respectively used for carrying out parallel processing on the Ireal and the Qreal, calculating to obtain a phase error ErrPhase, an amplitude error ErrMag and an error vector amplitude value, and reporting an analysis and processing result through a CPCI (Compact Peripheral Component Interconnect) bus. According to the invention, high-precision and anti-noise measurement of the satellite emission signal quality is realized through shunt parallel processing and a multi-bit-width quantization and smoothing strategy.

The application provides a visible light real-time communication positioning method and system based on EVM, which is based on a DCO-OFDM system and comprises the following steps: modulating communication information and preset positioning information onto corresponding subcarriers according to a preset resource allocation scheme; performing data processing on the subcarriers carrying the communication information and the preset positioning information; emitting a visible light signal by driving an LED with the subcarriers after data processing; receiving the visible light signal by a PD receiving end and converting the visible light signal into an electrical signal; converting the time domain signal of the electrical signal into a frequency domain signal, and performing equalization processing on the frequency domain signal; performing error vector magnitude calculation on the frequency domain signal after equalization processing, obtaining a new resource allocation scheme, extracting the communication information and the positioning information of the PD receiving end, replacing the new resource allocation scheme with the preset resource allocation scheme, and then repeating the execution in the next cycle; and decrypting the positioning information of the PD receiving end by a positioning algorithm module and outputting the positioning information.

The application discloses a protection method and device for a radio frequency power amplifier of a transmitter, the transmitter is set to maximum working power, and working current of the radio frequency power amplifier is measured and recorded; maximum current limiting of a system is obtained according to an error vector magnitude of the system and the working current of the radio frequency power amplifier, an electronic fuse circuit is configured, and the current limiting value of the electronic fuse circuit is set to the maximum current limiting of the system. The method provided by the application can protect the final stage power amplifier of the transmitter, and is simple, efficient, low in cost and the like.

An apparatus, such as a network node or gNB, determines an error vector magnitude (EVM) target allowed for a user equipment (UE), transmits the EVM target to the UE, and receives a corresponding signa

A radio frequency (RF) front-end circuit is provided. The RF front-end circuit may be disposed in a wireless device to support parallel time division duplex (TDD) and frequency division duplex (FDD) communications. In particular, the RF front-end circuit shares multiple antennas between communicating TDD sounding reference signals (SRS) in a TDD uplink and communicating FDD signals in an FDD downlink / uplink. In embodiments disclosed herein, the RF front-end circuit is configured to reduce phase / gain hopping in downlink / uplink FDD signals while switching TDD SRS transmissions between shared antennas. By reducing the phase / gain hopping in the FDD signal during SRS transmission, it is possible to improve the error vector magnitude (EVM) and / or signal-to-noise ratio (SNR) of the downlink / uplink FDD signal to thereby maintain FDD flux during FDD communication.

The invention provides a signal bandwidth-based adaptive peak cancellation method, which comprises the following steps of: acquiring the total bandwidth of an input OFDM (Orthogonal Frequency Division Multiplexing) signal, adaptively generating a peak clipping pulse function according to the total bandwidth, and carrying out peak cancellation processing on the input OFDM signal based on the generated peak clipping pulse function. According to the method, the high-efficiency and low-sidelobe peak clipping pulse can be generated only by knowing the total bandwidth of the OFDM signal without analyzing detail information such as the position of an internal subcarrier, so that the number of peak clipping iterations is reduced, the calculation complexity is reduced, and the performance balance between the adjacent band power ratio (ACPR) and the error vector magnitude (EVM) is improved.

This application provides an IQ imbalance calibration method, apparatus, signal transmitter, and zero-IF transceiver. The method includes: acquiring a reference baseband signal and a radio frequency (RF) signal output by the IQ modulation channel based on the reference baseband signal, and converting the RF signal into a modulation baseband signal; reconstructing the modulation baseband signal to generate a baseband feedback signal characterizing the distortion of the IQ modulation channel; obtaining pre-distortion parameters for compensating for IQ imbalance based on the reference baseband signal and the baseband feedback signal; performing pre-distortion processing on the reference baseband signal using the pre-distortion parameters to generate a baseband pre-distortion signal; and performing imbalance calibration on the IQ modulation channel based on the baseband pre-distortion signal. Because the IQ modulation channel is calibrated, the image rejection ratio and error vector amplitude performance of the output signal can be improved, thus increasing the calibration accuracy of the IQ modulation channel.

The application relates to the technical field of radio frequency chip power amplifiers, in particular to a dynamic error vector magnitude enhancement bias circuit structure. The structure comprises an output voltage adjusting circuit, a second-order thermal feedback circuit and a linearization circuit. By adjusting the resistance parameters of the resistors in the output voltage adjusting circuit, the reference voltage, the output voltage and the different temperature slope output voltage can be adjusted. On this basis, the first transistor and the fourth transistor adjust the edge spacing with the RF power tube in the layout, which is used for sensing the temperature change of the RF power tube, thereby effectively suppressing the gain fluctuation of the RF power tube. By adjusting the resistance parameters of the resistors in the second-order thermal feedback network, the thermal feedback capability can be flexibly enhanced or weakened. Based on the multidimensional control mechanism, the dynamic error vector magnitude can be significantly improved.

According to an example aspect of the present invention, there is provided an apparatus in a user equipment configured to receive, from a network node, a first information a first information of adjacent channel leakage power ratio, ACLR, requirement relaxation for the apparatus; and transmit, to the network node, at least one signal with a relaxed ACLR requirement based on the received first information.