H04L25/022

ANTI-ALIASING CHANNEL ESTIMATION APPARATUS AND METHOD AND RECEIVER
20170295036 · 2017-10-12 · ·

An anti-aliasing channel estimation apparatus and method and a receiver where the anti-aliasing channel estimation method includes: performing clock recovery and data synchronization on a received multicarrier signal with channel aliasing, to obtain a synchronized time-domain signal and a sampling phase; calculating an estimation signal after passing through a channel and being aliased based on a training sequence and the sampling phase, and obtaining a channel response and an aliasing signal response of each subcarrier of the multicarrrier signal based on the estimation signal and the frequency-domain signal. Therefore, channel estimation may be performed on the multicarrier signal with channel aliasing, influence of the channel aliasing on the bit error rate may be lowered, and transmission quality of the system may be improved.

Systems and methods for adaptive averaging in frequency domain equalization systems
09787338 · 2017-10-10 · ·

An example system comprises a first antenna and a modem. The first antenna is configured to receive a signal from a transmitting radio frequency unit. The signal includes data and a known sequence. The modem is configured to retrieve the known sequence from the signal, transform the known sequence and the data into a frequency domain, calculate averages of groups of neighboring frequency points in the frequency domain to reduce the effect of nonlinear noise in the signal, the neighboring frequency points corresponding to the preamble in the frequency domain, compare the calculated averages to an expected frequency response in the frequency domain, determine a correction filter to apply to the data based on the comparison, apply the correction filter on the data in the frequency domain to create corrected data, transform the corrected data from the frequency domain to the time domain, and provide the data.

In-situ die-to-die impedance estimation for high-speed serial links
09785607 · 2017-10-10 · ·

A receiver includes an analog-to-digital converter (ADC) module that receives a test signal via a transmission channel and provides a time domain representation of the test signal as received by the receiver, and a processor that determines a time domain representation of an impedance of the transmission channel based on the time domain representation of the test signal.

WIRELESS COMMUNICATION APPARATUS AND WIRELESS COMMUNICATION METHOD
20170288910 · 2017-10-05 · ·

A wireless communication apparatus configured to select an allocation system for transmission symbols on the basis of transmission line situations between the wireless communication apparatus and terminals includes a channel estimator to estimate transmission line coefficients between communication target terminals and sub-arrays, a resource scheduler to generate, on the basis of the transmission line coefficients, mapping information and transmission weight information by spatial multiplexing and frequency multiplexing and select and output the mapping information and the transmission weight information by one of the multiplexing systems, a symbol mapper to map transmission symbols on a frequency axis on the basis of the mapping information from the resource scheduler, and a pre-coder to perform, on the basis of the transmission weight information from the resource scheduler, a weighting operation concerning a signal mapped by the symbol mapper.

Scattered pilot pattern and channel estimation method for MIMO-OFDM systems
09780984 · 2017-10-03 · ·

A method and apparatus are provided for reducing the number of pilot symbols within a MIMO-OFDM communication system, and for improving channel estimation within such a system. For each transmitting antenna in an OFDM transmitter, pilot symbols are encoded so as to be unique to the transmitting antenna. The encoded pilot symbols are then inserted into an OFDM frame to form a diamond lattice, the diamond lattices for the different transmitting antennae using the same frequencies but being offset from each other by a single symbol in the time domain. At the OFDM receiver, a channel response is estimated for a symbol central to each diamond of the diamond lattice using a two-dimensional interpolation. The estimated channel responses are smoothed in the frequency domain. The channel responses of remaining symbols are then estimated by interpolation in the frequency domain.

METHOD AND APPARATUS FOR IMPROVING MULTI-USER MULTIPLEXING PERFORMANCE, DEVICE, AND STORAGE MEDIUM
20220052881 · 2022-02-17 ·

This application provides a method and an apparatus for improving multi-user multiplexing performance, a device, and a storage medium. In the method, a network device configures base sequence identifiers for a plurality of terminals by using RRC signaling, where there is no orthogonality between base sequences indicated by the base sequence identifiers of all the terminals; the terminal obtains the base sequence identifier that is configured by the network device by using the RRC signaling, and sends a sounding reference signal SRS based on the base sequence identifier; the network device performs SRS detection on the plurality of terminals based on a quasi-orthogonal sequence, to obtain channel information for sending an SRS by each terminal, and performs channel prediction based on the channel information of each terminal, to obtain a channel prediction result.

Data interpretation with noise signal analysis
09780887 · 2017-10-03 · ·

Methods and systems for providing and processing data are disclosed. An example method can comprise determining a first weighted probability based on a probability of occurrence of a noise signal and a first likelihood ratio. The first likelihood ratio is based on a frequency distribution of the noise signal. An example method can comprise determining a second weighted probability based on a probability of non-occurrence of the noise signal and a second likelihood ratio. An example method can comprise determining a combination of the first weighted probability and the second weighted probability, and providing the combination to a decoder configured to decode a value based on the combination.

ALGORITHM AND ARCHITECTURE FOR CHANNEL ESTIMATION IN 5G NEW RADIO
20220052880 · 2022-02-17 ·

This disclosure relates to apparatuses, systems, and methods for channel estimation, and in particular channel estimation for 5G New Radio systems. The channel estimation interpolates, prior to performing a de-spreading operation, a first combined channel estimation and a second combined channel estimation to provide from the first combined channel estimation one or more channel estimation values at indices associated with the second combined channel estimation and/or to provide from the second combined channel estimation one or more channel estimation values at indices associated with the first combined channel estimation.

Method of channel estimation by phase rotation in an orthogonal frequency division multiplexing (OFDM) system

The method includes receiving communication signals in a time domain and to aa frequency domain, providing resource blocks in the frequency domain including a first and second resource block, selecting first pilot signals from first resource block and second pilot signals from second resource block, calculating a first average value based on the first pilot signals, calculating a second average value, determining a phase difference between the first and second pilot signals using the first and second average values, adjusting a first phase of first resource block using the phase difference, providing a first waveform using the first resource block with adjusted the first phase and the second resource block, applying a smoothing filter against the first waveform to generate a second waveform, generating a third waveform using at least the first and third set of phase and amplitude differences, and converting third waveform from frequency domain to time domain.

Wireless communication apparatus for low-complexity beamforming feedback and method of operating the apparatus

A method of operating a wireless communication apparatus configured to support adaptive beamforming of a base station, the method including receiving a sounding packet from the base station through a plurality of sub-carriers, generating first channel information corresponding to first sub-carriers among the plurality of sub-carriers based on the sounding packet, performing an interpolation operation using the first channel information to generate second channel information corresponding to second sub-carriers among the plurality of sub-carriers, generating first beamforming feedback including the first channel information and the second channel information, and transmitting the first beamforming feedback to the base station.