Aspects of the disclosure relate to devices, systems and methods for multi-beam formation. A user equipment (UE) may determine a sampling interval for references signals to be transmitted by a base station for an upcoming control or data communication. For example, the UE may determine a maximum sampling interval tolerable for channel estimation and select the sampling interval based on the maximum. In some examples, the UE determines the sampling interval based on characteristics of its motion. The UE transmits an indication of the sampling interval to the base station. Based on the indication, the base station selects an interval for the reference signals and transmits the reference signals to the UE to enable it to perform the channel estimation for the multi-beam. The base station may determine to select the interval for the reference signals such that it is less than or equal to the sampling interval indicated by the UE.

A wireless communication method includes receiving, by a first wireless device during a training phase, reference tones using a first number of resource elements from a transmitter of a second wireless device, wherein the first wireless device comprises multiple receiving antennas, estimating, by the first wireless device, from the receiving the reference tones, a second order statistics of wireless channels between the multiple receiving antennas and the transmitter of the second wireless device, and performing channel estimation, during an operational phase subsequent to the training phase, using the second order statistics and reference tones received on a second number of resource elements, wherein the second number is less than the first number.

Method and one or more first devices for supporting calibration of a multi-antenna array comprised in a first antenna device operative with a wireless communication network. The first device(s) provide phase correcting information, to be used in calibration of the multi-antenna array, based on covariances corresponding to recurrent displacement vectors of the multi-antenna array. Said covariances being based on channel estimates estimated from certain radio signals received after transmission over radio propagation channels between said multi-antenna array of the first antenna device and one or more second antenna devices operative with the wireless communication network.

Methods, systems, and devices for wireless communications are described. In some examples, a user equipment (UE) may receive a control message indicating a set of sampling beams defined for the UE. The UE may measure a set of received signal strengths for communications from a wireless node associated with a set of linear combinations of sampling beams from the set of sampling beams defined at the UE. The UE may calculate a set of entries of a channel covariance matrix based on the set of received signal strengths of the set of linear combinations of the sampling beams from the set of sampling beams defined for the UE. As such, the UE may communicate with the wireless node based on applying a set of beam weights to an antenna array of the UE. In some examples, the set of beam weights may be based on the channel covariance matrix.

Methods for determining variability in a state of a medium, include monitoring the medium and determining the variability in the state of the medium based on the processing of the response over time based on the response detected at the at least one receive element over time. Monitoring the medium can include generating a transmit signal, transmitting it into the medium using a transmit element, and receiving a signal from the medium at a receive element. The transmit and receive elements can be decoupled from one another. The transmit and receive elements can have differing geometry. The determined variability in the state of the medium can be used to provide notifications and/or take automated actions.

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.

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.

A device is configured to calculate a set of channel estimates for a plurality of sub-carriers based on a plurality of pilot-symbols and/or data-symbols carried by said plurality of sub-carriers; calculate a set of equalizers for the plurality of sub-carriers based on the set of channel estimates; perform an equalization on a plurality of data-symbols using the set of equalizers for obtaining a plurality of equalized symbols; perform a soft-slicing or hard-slicing procedure comprising obtaining a plurality of estimated symbols based on the equalized symbols; calculate at least one diagonal-loaded interference-plus-noise covariance matrix, based on the set of estimated symbols; de-map the plurality of data symbols to soft-bits, based on the at least one diagonal-loaded interference-plus-noise covariance matrix, the set of channel estimates or an updated version thereof; and feed the soft-bits to a channel decoder.

Embodiments of the present disclosure provide a method performed by a communication device. The method includes obtaining, in frequency domain, channel estimation for a transmission unit for a channel between the communication device and another communication device, and calculating correlation coefficients for the transmission unit based on the channel estimation. The method also includes obtaining a delay spread for the channel from the calculated correlation coefficients.

The present disclosure relates in general to telecommunications. In one of its aspects, the technology presented herein concerns a method, implemented in an Access Point (AP), for transmitting data intended for a terminal in a cell-free massive Multiple-Input and Multiple-Output (MIMO) communications system. The AP is grouped into a cluster together with other APs and the cluster operates autonomously. The cluster is connected to, and managed by, one Central Processing Unit (CPU). A message that the AP is selected to serve the terminal and data intended for said terminal are received from the CPU. Power control is independently conducted, exclusively considering the terminals that are served by the AP itself. Thereafter, said intended data is transmitted to the terminal.