Method and apparatus are provided for estimating first downlink (DL) channel information of first DL channels in accordance with reference signals received on first uplink (UL) channels, the first UL channels being a subset of available UL channels, and the first DL channels corresponding to the first UL channels. Channel feedback is received for a set of DL channels, and second DL channel information is estimated in accordance with the estimated first DL channel information and the received channel feedback.

According to one aspect, a network node is provided. The network node including processing circuitry configured to: estimate a spatial spectrum associated with a plurality of wireless devices, determine active spatial directions for the plurality of wireless devices based at least on the estimated spatial spectrum, and determine Multiple User-Multiple Input Multiple Output, MU-MIMO, pairing based at least on the determined active spatial directions.

A communications device includes a uniform linear array of M antennas and a field programmable gate array (FPGA) having pipelined stages in which execution of overlapping instructions estimate a direction of arrival of RF signals from multiple sources. A preprocessing stage of the FPGA includes at least one configurable logic block configured to apply forward/backward averaging spatial smoothing to a signal space matrix extracted from a covariance matrix in the preprocessing stage. The FPGA further includes at least one configurable logic block configured to compute the direction of arrival angle for the RF signals using a least squares method.

A distributed base station system comprises a remote radio unit, RRU, and a base band unit, BBU, connected to the RRU over a fronthaul link, the RRU being connected to N antennas. The method comprising by the RRU: obtaining uplink signals as received at the N antennas from a number of User Equipment, UEs, wirelessly connected to the RRU; obtaining a channel estimation matrix of the wireless communication channels; determining an interference covariance estimation matrix based on the obtained channel estimation matrix and on other channel information different from the channel estimation matrix; sending information on the channel estimation matrix and on the interference covariance estimation matrix to the BBU; determining intermediate signals based on the uplink signals, the channel estimation matrix and the interference covariance estimation matrix, and sending the intermediate signals to the BBU.

Aspects of the present disclosure may involve use of a radio frequency receiver and in such a receiver, tracking multipath gains and delays of multipath reflections corresponding to an OFDM multipath transmission channel. The gains and delays are based on time-domain evolution of the channel impulse response. Multipath reflections are searched for and then used to calculate channel correlation information to provide channel estimations to aid in mitigating or cancelling distortion of the received signal.

A method includes calculating first high dimensional channel characteristics of a first frequency band in accordance with measurements of the first frequency band; estimating a power angle delay spectrum (PADS) in accordance with the first high dimensional channel characteristics of the first frequency band; determining a domain conversion matrix for a second frequency band in accordance with the PADS; and generating second high dimensional channel characteristics of the second frequency band in accordance with the domain conversion matrix and the first high dimensional channel characteristics of the first frequency band.

An apparatus, method and computing program is described including: receiving one or more received symbols and one or more received bits, wherein the received symbols are received at a receiver of a transmission system including a transmitter, a channel, and the receiver; converting one or more of the received bits that are deemed to be correct into one or more estimated transmission symbols; generating an estimated channel transfer function based on one or more of the estimated transmission symbols and corresponding received symbols; and providing training data pairs, each training data pair including a first element based on the estimated channel transfer function and a second element based on the corresponding received symbols.

A receiving circuit (100) includes: a channel estimation unit (20) configured to estimate a channel response vector based on a reception signal received via a plurality of antennas (10); a covariance matrix estimation unit (30) configured to estimate a covariance matrix based on the reception signal and the channel response vector; a covariance matrix correction unit (40) configured to correct the covariance matrix by adding, to the covariance matrix, an offset value with a value in components including off-diagonal elements of the matrix; and a weight multiplication unit (50) configured to estimate a transmission signal by multiplying a weight based on the channel response vector and the corrected covariance matrix by the reception signal.

Aspects of the subject disclosure may include, for example, obtaining, over an uplink (UL) using an aggregation of modular antenna arrays, a modulated signal that includes feedback transmitted by a user equipment (UE), wherein the aggregation of modular antenna arrays comprises multiple groups of antenna elements, after the obtaining the modulated signal, performing a demodulation of the modulated signal, determining demodulator constellation errors from the demodulation of the modulated signal, performing an error gradient weight adaptation responsive to the determining the demodulator constellation errors to derive revised weights for various antenna elements of the multiple groups of antenna elements, and applying the revised weights to the various antenna elements of the multiple groups of antenna elements to adjust signals received over the UL. Other embodiments are disclosed.

Facilitating sparsity adaptive feedback in the delay doppler domain in advanced networks (e.g., 4G, 5G, 6G, and beyond) is provided herein. Operations of a method can comprise determining, by a first device comprising a processor, a channel covariance matrix in a time-frequency domain based on a channel estimation associated with reference signals received from a second device. The method also can comprise decomposing, by the first device, the channel covariance matrix into a group of component matrices. Further, the method can comprise transforming, by the first device, respective matrices of the group of component matrices into respective covariance matrices in a delay doppler domain. The method also can comprise determining, by the first device, channel state information feedback in the delay doppler domain.