164results about "Equalisers" patented technology

Accordingly, there are disclosed herein receivers and receiving methods that provide a graceful transition from PAM2 to PAM4 signaling. One illustrative method includes: negotiating a link speed having PAM4 signaling; performing adaption of at least one gain or filter coefficient during PAM2 signaling; switching to PAM4 detection before receiving PAM4 signaling; disabling said adaptation before said switching to PAM4 detection; detecting PAM4 signaling using at least one statistic of detected PAM4 symbols; and enabling said adaptation after PAM4 signaling is detected. Another illustrative method includes: negotiating a link speed having PAM4 signaling; adapting at least one of gain and filter coefficients during PAM2 signaling; monitoring for a change in at least one signal characteristic while performing PAM2 detection; and transitioning to PAM4 detection after detecting said change.

The invention discloses a channel estimation and equalization method suitable for an OFDM satellite communication system, and relates to the technical field of satellite communication. The method comprises the following steps: firstly, calculating a frequency domain channel estimation result, then extracting a time domain channel response with the maximum energy, then calculating amplitude information and the frequency domain channel response, or calculating an average phase value after compensating time delay for a preliminary channel estimation result to obtain a phase value of a data symbol; and finally, balancing the channel according to the amplitude information and the frequency domain channel response or the phase value of the data symbol. According to the method, a channel model of satellite communication is fully considered, the channel estimation and equalization method is adaptively simplified according to channel characteristics, and the method is more practical.

Various aspects of the present disclosure generally relate to wireless communication. Some aspects more specifically relate to discrete Fourier transform spread orthogonal frequency division multiplexing (DFT-S-OFDM) waveform pre-equalization for MIMO communications. A receiver device, such as an extended reality (XR) device, may be configured to offload a portion of data processing to a companion device, such as a user equipment (UE). In some aspects, the UE may generate a DFT-S-OFDM waveform and may apply a pre-equalization to the DFT-S-OFDM waveform. Applying the pre-equalization to the DFT-S-OFDM waveform may include applying a minimum mean square error (MMSE) pre-equalization to the DFT-S-OFDM waveform. The receiver device may receive the pre-equalized DFT-S-OFDM waveform from the UE and may process the pre-equalized DFT-S-OFDM waveform. For example, the receiver device may decode the pre-equalized DFT-S-OFDM waveform without performing fast Fourier transform (FFT) or inverse discrete Fourier transform (IDFT) operations.

A system and computer-implemented method using a physical information neural network for data communication are provided. At a transmitter, the method is configured to obtain source data to be transmitted to encode the source data into code words based on a forward error correction code, map the code words to amplitude symbols, modify the mapped amplitude symbols into pre-equalized symbols including pre-distorted channel impairment symbols based on a predetermined physical model, and transmit the digital data of the pre-equalized symbols as channel data over a channel. At a receiver, the method is configured to receive and demodulate channel data from a channel to generate initial estimates of bits of the received channel data, mitigate channel noise and waveform distortion in the channel data based on the initial estimates, convert the channel data consisting of shaped non-uniform symbols as a non-uniform data sequence into an unshaped bit sequence, decode the unshaped bit sequence, correct residual errors in the converted channel data, and store the corrected channel data in a data sink.

The invention discloses an OFDM (Orthogonal Frequency Division Multiplexing) signal time-frequency collaborative equalization distortion suppression method, and belongs to the field of wireless communication. According to the invention, the problems of high complexity and poor transmission reliability of the existing short cyclic prefix method are solved. According to the invention, an OFDM system based on time domain oversampling and frequency domain interpolation equalization is adopted at a receiving end, and the oversampling algorithm can enhance the power of useful signals by properly broadening an equalization frequency band, so that the equalization effect is enhanced; according to the frequency domain interpolation equalization algorithm, weighted interpolation processing is carried out on frequency domain receiving signals, so that spectrum details can be better captured, and compensation and correction of an energy migration phenomenon generated by spectral lines in a frequency band due to a channel effect are realized. Through time-frequency cooperative processing at a receiving end, interference can be efficiently suppressed, stable and reliable demodulation precision and communication quality can be ensured, frequency spectrum resource loss caused by additional extension of a cyclic prefix can be avoided, and the frequency spectrum utilization efficiency of the system is further remarkably improved. The method can be applied to the field of wireless communication.

In one aspect, an apparatus includes: a front end circuit to receive and process incoming radio frequency (RF) signals into orthogonal frequency division multiplexing (OFDM) samples; a fast Fourier transform (FFT) engine to receive and convert the OFDM samples into frequency domain sub-carriers; a demodulator to demodulate the frequency domain sub-carriers; a channel estimator to: compute a first pilot channel estimate for a first channel condition comprising a flat channel condition and a second pilot channel estimate for a second channel condition comprising a selective channel condition based on a first set of pilot sub-carriers of the frequency domain sub-carriers; and select one of the first and second pilot channel estimates using the first and second pilot channel estimate; and a control circuit to configure at least the demodulator based at least in part on the selected first or second pilot channel estimate.

The invention discloses a Turbo equalization-based single-carrier underwater acoustic communication Doppler compensation method. The Turbo equalization-based single-carrier underwater acoustic communication Doppler compensation method is combined with Turbo equalization to jointly design Doppler compensation, equalization, decoding and other processing of an underwater acoustic communication receiving end. Doppler invariance of front and back synchronous sequence signals of each frame of data segment is utilized to estimate a Doppler factor initial value, a Doppler factor candidate set is constructed by utilizing the Doppler factor initial value, the Doppler compensation effect is judged according to the size of an extrinsic information absolute value of a decoder, the optimal factor and soft symbol are selected to perform next iteration, and a Doppler compensation result is obtained. Therefore, a combined Turbo equilibrium iteration structure is formed. Compared with a traditional Doppler estimation compensation method, the method can cope with the influence of multipath Doppler in shallow sea mobile underwater acoustic communication, reduces Doppler factor estimation deviation caused by Doppler inconsistency of each path, improves the resolution of the estimated Doppler factor, and remarkably improves the decoding performance.

The invention discloses a buoy satellite communication system channel estimation method and system in a marine environment, and the method comprises the steps: carrying out the preliminary channel estimation at a receiving end through a least square algorithm, and then achieving the fine optimization through an ARCENet model based on an attention mechanism and a residual network, the residual structure improves the training stability; and the interpolation layer adopts a generative adversarial network to realize high-precision response reconstruction. The method has the advantages that the calculation load is reduced through the lightweight network design, and the dynamic characteristics of the channel are captured through nonlinear mapping; the sparse pilot frequency configuration is kept to save spectrum resources, and the robustness under the condition of low signal-to-noise ratio is remarkably improved. And finally, high-precision recovery of channel response under a complex sea condition is realized, and the reliability of a buoy satellite communication link is effectively guaranteed.

A digital filter (6) performs polarization variation compensation for data of at least two polarizations in which a plurality of known signals are inserted at predetermined positions in each frame by means of a filter in which a tap coefficient is set. Before a frame synchronization unit (4a) generates a frame signal from an output signal of a digital filter, a tap coefficient update circuit (7) updates the tap coefficient such that the difference between the amplitude value of the data and the amplitude value that the data should take is small. After a frame signal is generated, a tap coefficient updating circuit (7) receives the frame signal in a feedback manner, detects a known signal from the data on the basis of the frame signal, and updates the tap coefficient such that the difference between the detected known signal and the true value of the known signal becomes small.

To provide a method for facilitating effective and efficient soft mounting of an examination order of a different type in an examination system, and provide a signal processing examination system.SOLUTION: A signal processing examination method comprises the steps of: selecting a signal processing mode among a header conclusion mode, a contraction header training mode, and a contraction header mode; executing signal processing information determination processing in accordance with a selection result of the signal processing mode; and executing modulation / demodulation related processing in accordance with a result of the signal processing information determination processing. In the contraction header mode, processing is executed to a communication signal. Header information cannot be easily used at first in the communication signal itself. Demodulation parameter information is advantageously derived / developed / inserted from the other information in the communication signal.SELECTED DRAWING: Figure 8

A receiving system includes one or more subarrays, a phase rotation unit, an equalization unit, and a calculation unit. The subarray includes a set of a plurality of elements having a strong correlation in a Doppler frequency transition. The phase rotation unit performs, on a reception signal received by each element of the subarray, phase rotation processing of a phase rotation amount calculated for the subarray to which the element that has received the reception signal belongs. The equalization unit performs equalization processing on the reception signal subjected to the phase rotation processing. The calculation unit averages phase amounts of the signals received by the elements belonging to the subarray for each subarray, and calculates the phase rotation amount for performing phase compensation using the averaged phase amount.

A signaling system includes a pre-emphasizing transmitter and an equalizing receiver coupled to one another via a high-speed signal path. The receiver measures the quality of data conveyed from the transmitter. A controller uses this information and other information to adaptively establish appropriate transmit pre-emphasis and receive equalization settings, e.g. to select the lowest power setting for which the signaling system provides some minimum communication bandwidth without exceeding a desired bit-error rate.

The present application discloses a dynamic power consumption management system, comprising: an equalization algorithm circuit, a carrier recovery algorithm circuit, and an IQ imbalance algorithm circuit; an equalization algorithm coefficient update circuit connected to an output end of the carrier recovery algorithm circuit and configured to provide equalization algorithm update coefficients to the equalization algorithm circuit; a carrier recovery frequency offset and phase noise calculation circuit connected to an output end of the equalization algorithm circuit and configured to provide carrier recovery frequency offset and phase noise coefficients to the carrier recovery algorithm circuit; an IQ imbalance algorithm coefficient update circuit connected to an output end of the IQ imbalance algorithm circuit and configured to provide IQ imbalance algorithm coefficients to the IQ imbalance algorithm circuit; a signal-to-noise ratio reporting circuit connected to an output end of the IQ imbalance algorithm circuit and configured to acquire a signal-to-noise ratio of the entire system; and a management circuit configured to determine the equalization algorithm update coefficients, the carrier recovery frequency offset and phase noise coefficients, and the IQ imbalance algorithm coefficients based on the signal-to-noise ratio. The present application can reduce the power consumption of chips.

Methods, systems, and devices for wireless communications are described. A transmitting device (e.g., a user equipment (UE) or base station) may reduce a peak to average power ratio (PAPR) by clipping signals transmitted to a receiving device according to a clipping level. The receiving device may receive, from the transmitting device, an indication of the clipping level associated with a reference signal. The receiving device may receive the reference signal and identify distortions based on the clipping level. The receiving device may iteratively reconstruct peaks of the clipped reference signal until the receiving device is able to obtain accurate pilot symbols for use in channel estimation. The techniques described herein may enable receiving devices to improve efficiency and reliability of communications by improving channel estimation, which may increase the probability of successfully decoding transmitted information.

The present application discloses an equalizer circuit, which includes a current source module, an RC network, and a differential transistor pair, the current source module being electrically connected to the RC network, the RC network being electrically connected to the differential transistor pair, the equalizer circuit further including an adjustable active inductor module electrically connected to the first transistor and the second transistor in the differential transistor pair, respectively, and a control module electrically connected to the current source module, the RC network, and the adjustable active inductor module, respectively, for adjusting the performance parameters of the current source module, the RC network, and the adjustable active inductor module to change the frequency of the dominant pole and the non-dominant pole of the equalizer circuit. The equalizer circuit can obtain compensation curves for different frequency peaking, and can well and harmoniously solve the channel compensation problem in different protocols and different rates, solving the problem that the gain boost of each frequency peaking cannot be adjusted within 0-15 dB in the related art due to the channel attenuation to be compensated by the equalizer being different in different protocols and different rates.

Clock data recovery system with: a feedforward equalizer configured to equalize a first input signal received from an analog-to-digital controller based on a plurality of received tap coefficients, thereby producing a first output signal; an adder configured to add the first output signal and a feedback signal from a decision feedback equalizer, thereby producing a second output signal; a double limiter configured to receive the second output signal and provide a first group of preliminary decisions to a decision feedforward equalizer, the decision feedforward equalizer providing an equalized output signal; a second adder configured to generate a first error signal based on the equalized output signal from the decision feedforward equalizer, wherein the plurality of received tap coefficients are based on the error signal; and a clock data recovery circuit configured to receive the first output signal and provide a setting signal for the analog-to-digital controller.

This invention discloses a pre-equalization compensation method for a terminal in a TDD-OFDM direct conversion system with known transmitter IQI and nonlinear parameters. The method includes: the base station cyclically sending P different training sequences to the terminal; the terminal using a sliding window least squares-based channel state information tracking algorithm to track and estimate the channel state information, where δ is a threshold representing the correlation of the channel within adjacent symbol periods; and pre-equalization compensation performed directly at the terminal. Using the pre-equalization compensation algorithm, a modified data sequence can be obtained and sent to the base station. This invention considers three factors in wireless communication systems: I-path and Q-path imbalance caused by the non-ideal nature of analog components in RF transceivers, power amplifier nonlinearity, and multipath channels. It enables distributed processing within the cell, effectively reducing the demodulation burden on the base station and has wider applicability than traditional compensation methods.

A radio communication method includes: by a radio terminal device, generating position indicating signals that are different between blocks of radio resources each of which is an allocation unit of data; mapping the position indicating signals generated and transmission data to the blocks; and transmitting a signal including the blocks; by a base station device, receiving the signal including the blocks of the radio resources; evaluating continuity of the blocks, based on the position indicating signals mapped to the blocks; and demodulating data mapped to the blocks for each radio terminal device, based on an evaluation result.

According to an embodiment, a method of an electronic device for receiving a signal in an OFDM system may comprise an operation of determining a common channel estimation value on the basis of demodulation reference signals belonging to a resource block including a plurality of OFDM symbols adjacent in the time domain and a plurality of subcarriers adjacent in the frequency domain. The method of the electronic device may comprise an operation of determining a port reduction filter for reducing the dimension of a reception signal on the basis of the common channel estimation value. The method of the electronic device may comprise an operation of determining a covariance matrix on the basis of a reception signal having passed through the port reduction filter. The method of the electronic device may comprise an operation of performing channel equalization on the basis of the port reduction filter and the covariance matrix.

A receiver circuit includes an equalizer configured to generate an equalized signal by equalizing an input data signal transmitted through a communication channel based on an equalization coefficient, a clock data recovery circuit configured to generate a data clock signal and an edge clock signal based on the equalized signal, generate a data sample signal including a plurality of data bits by sampling the equalized signal in synchronization with the data clock signal, and generate an edge sample signal including a plurality of edge bits by sampling the equalized signal in synchronization with the edge clock signal, and an equalization control circuit configured to control the equalization coefficient by comparing the plurality of data bits and the plurality of edge bits.

According to an embodiment, a method performed by means of an electronic device comprises an operation of obtaining a signal on a plurality of resource elements (REs). The method comprises the operations of: selecting reference REs from the plurality of REs on the basis of the time interval between symbols and the frequency interval between the symbols; performing channel estimation on the basis of the reference REs; obtaining, on the basis of a result of the channel estimation, a plurality of first weights corresponding to the reference REs; obtaining, on the basis of the plurality of first weights, a plurality of second weights corresponding to other REs that are distinct from the reference REs from among the plurality of REs; and obtaining, on the basis of the plurality of first weights and the plurality of second weights, information corresponding to the signal.

A wireless terminal (1) is configured to, (a) when transmitting uplink control information in a first subframe of a radio frame, determine the number of coded symbols (Q') for the uplink control information by a first calculation method, and (b) when transmitting the uplink control information in a second subframe of the radio frame, determine the number of the coded symbols (Q') for the uplink control information by a second calculation method different from the first calculation method. This can contribute, for example, to adjusting redundancy of coded uplink control information (UCI) bits on a per-subframe basis.

The present invention relates to a signal design technique resistant to phase distortion and may provide a method of a transmitter, the aspect comprising the steps of: modulating a sequence of source bits to be transmitted to a receiver to generate a first block of symbols; inserting at least one pilot into the first symbol block to generate a second symbol block; performing cumulative linear coding on the second symbol block to generate a third symbol block; performing real phase conversion on the third symbol block to generate a first signal converted to a phase value; adding a cyclic prefix (CP) to the first signal to generate a second signal; and wirelessly transmitting the second signal to the receiver.

Proposed is a high-speed communication device based on a duobinary signal. The device may include an output circuit configured to output a duobinary signal. The device may also include a first compensation circuit configured to apply a first equalization (EQ) for amplifying the duobinary signal to a voltage to be transitioned during voltage transition of the duobinary signal. The device may further include a second compensation circuit configured to apply a second EQ for saturating the duobinary signal to a predetermined voltage after the first EQ is applied.

A method may include testing, at a receiver, a full equalizer to determine a performance parameter. The method may include setting, at a receiver, a target performance parameter based on the performance parameter. The method may include performing, at the receiver, a first equalization operation based on the target performance parameter. The method may include setting, at the receiver, a deferred decision region based on the target performance parameter and the first equalization operation. The method may include performing, at the receiver, a second equalization operation based on the target performance parameter.

The invention discloses a frequency domain super-resolution reconstruction OFDM (Orthogonal Frequency Division Multiplexing) waveform distortion suppression method, and belongs to the field of wireless communication. The method solves the problems that an existing method is high in complexity, sensitive to channel conditions and poor in error rate performance. The method comprises the following steps: constructing an interpolation matrix at a receiving end, and carrying out weighted interpolation on a frequency domain receiving signal by utilizing adjacent spectral line weighting to generate an interpolated frequency domain signal; the method comprises the following steps of: deducing to obtain a time domain equivalent relation of interpolation processing of a transmitting end and a receiving end by combining the logic of performing frequency domain zero insertion on an original frequency domain signal by a transmitting end, further jointly estimating an interpolated channel, and designing an equalizer according to a minimum mean square error criterion to perform equalization processing on the interpolated frequency domain signal to complete data recovery. According to the method, the problem of inter-symbol interference caused by insufficient CP of a common OFDM system with insufficient cyclic prefixes is solved, inter-symbol interference and inter-subcarrier interference caused by insufficient cyclic prefixes can be effectively suppressed, and accurate demodulation data can be obtained. The method can be applied to the field of wireless communication.

The present disclosure provides a frequency offset estimation method, which includes: extracting sampling points from an input signal at a set interval to obtain multiple sampling point groups, and the set interval of each sampling point group is different; processing the current sampling point and the extracted sampling points in each sampling point group separately to obtain complex angle data corresponding to the set interval; and determining the frequency offset estimation value of the current input signal using the complex angle data corresponding to the set interval. The frequency offset estimation method does not require switching the frequency offset estimation during the frequency offset estimation process, and can achieve large-range and high-precision frequency offset estimation. The present disclosure also provides a frequency offset estimation device, an electronic device, and a computer-readable medium.

The tap coefficient control circuit (12) sets the tap coefficient updated by the second tap coefficient updater (11) as the initial value of the convergence action of the tap coefficient of the first digital filter (13) updated by the first tap coefficient updater (14), arranges the tap coefficients set as the initial value in descending order according to the degree of contribution to the convergence action of the first tap coefficient updater (14), judges the tap coefficients above the upper specified number as valid, judges the tap coefficients below the specified number as invalid, sets the tap coefficients of the first digital filter (13) corresponding to the tap coefficients judged to be invalid to zero and does not use them in the calculation of the first tap coefficient updater (14) until the next judgment result comes out.

Data equalization system, featuring: a data clock input configured to receive a clock signal; an input node which is to be operated in such a way that it receives a data signal of transmission symbols which change their state synchronously with the clock signal; a first branch which is connected to the input node; and a second branch configured to receive a modification of the data signal, wherein at least one of a weighting of the first branch and a weighting of the second branch is modulated by a dynamic control parameter that repeats synchronously with each transmission symbol.

A method of Narrow-band Internet of Things physical random-access channel (NPRACH) communication includes: transmitting, from a user equipment (UE), a Narrow-band Internet of Things (NB-IoT) Orthogonal Frequency-Division Multiple Access (OFDMA) symbol using a transmit inverse fast Fourier transform (Tx-IFFT) having a first length; processing, at lower physical layer (LPHY) of a baseband unit (BBU), the NB-IoT OFDMA symbol using a receive fast Fourier transform (Rx-FFT) having a second length different from the first length to generate an Rx-FFT output; sending, from the LPHY of the BBU to upper physical layer (UPHY) of the BBU, a selected number of values of the Rx-FFT output corresponding to desired resources block in the NB-IoT OFDMA symbol; filtering, at the UPHY, intercarrier interference (ICI) from the selected number of values of the Rx-FFT output; and reconstructing, at the UPHY, the NB-IoT OFDMA symbol.