In a general aspect, various fields of a PHY frame are used for motion detection. In some aspects, a first training field and a second, different training field are identified in a PHY frame of each wireless signal transmitted between wireless communication devices in a wireless communication network. A first time-domain channel estimate and a second time-domain channel estimate are generated for each wireless signal. The first time-domain channel estimate is based on a first frequency-domain signal included in the first training field, while the second time-domain channel estimate is based on a second frequency-domain signal included in the second training field. A determination is made whether motion has occurred in a space during the time period based on the first time-domain channel estimates, and a location of the motion within the space is determined based on the second time-domain channel estimates.

A method in a wireless receiver for estimating a channel. The method includes receiving a signal comprising a plurality of transmission layers, each layer having at least one reference signal according to a predefined reference signal sequence; determining a window size for performing a sampling operation, wherein the operation is performed in a transformed domain of the received signal; selecting a channel tap length, from a range of channel tap lengths, wherein the selection is based on the window size, a noise mean and a noise variance. The channel estimation is performed from a reference signal sequence for the at least one reference signal and based on samples corresponding to the selected channel tap length.

Certain aspects of the present disclosure relate to methods and apparatus for a UE to flexibly indicate a preferred precoding resource block group (PRG) size to a base station (e.g., an eNB).

The described technology is generally directed towards adaptively changing which transmission scheme a user equipment is to use based on a Doppler metric (e.g. Doppler frequency) as evaluated against a threshold Doppler value. A network instructs a user equipment to use a Rank-1 precoder cycling transmission scheme if the Doppler metric of user equipment is above a threshold value, or to use a closed loop MIMO transmission scheme if the user equipment has a Doppler metric below the threshold value. The network can instruct the user equipment via a suitable message, or by switching off TPMI and notifying the user equipment thereof.

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.

In an aspect, a UE estimates channel state(s) of channels(s) between the UE and network node(s) based on DL RS(s) for positioning that are scheduled and transmitted on DL resources from network node(s). The UE may apply TR filter(s) derived based on the estimated channel state(s) to a UL-RS for positioning. The UE may transmit the TR filtered UL-RS on UL resources which are associated with the DL resources of the DL-RS(s) and which are scheduled by the network node(s). The association between the UL resources and the DL resources may be indicated to the UE by the network node(s).

A method for minimizing a time domain mean square error (MSE) of channel estimation (CE) includes estimating, by a processor, a power delay profile (PDP) from a time domain observation of reference signal (RS) channels; estimating, by the processor, a noise variance of the RS channels; and determining, by the processor, a first arrival path (FAP) value and a delay spread estimation (DSE) value based on the estimated PDP and the estimated noise variance for minimizing the MSE of CE.

Methods, systems, and devices for wireless communications are described. A user equipment (UE) may receive, from a base station, a request that the UE report a predicted future channel state information measurement. Upon receiving the request, the UE may measure, during a first time period, a channel to obtain measured channel state information. The UE may then determine the predicted future channel state information for a second time period based on the measured channel state information. In some case, the second time period may be subsequent to the first time period. Upon determining the predicted future channel state information measurement, the UE may transmit, to the base station, a channel state information report. In some aspects, the channel state information report may be indicative of the predicted future channel state information measurement.

Technologies to improve throughput in wireless multiple-input-multiple-output (MIMO) and single-input-single-output (SISO) systems are described. A first device includes a baseband processor with an Orthogonal Frequency Division Multiplexing (OFDM) circuitry that uses a digital multi-carrier modulation scheme that defines a set of data subcarriers, a set of pilot subcarriers, and a direct current (DC) subcarrier to communicate data in a wireless channel between the first device and a second device. The baseband processor also includes subcarrier pre-equalization logic that receives, from the second device, feedback data indicative of a frequency selective fading characteristic of the wireless channel and adjusts a first amplitude value of a subset of the set of data subcarriers to a second amplitude value. Adjusting the first amplitude value to the second amplitude value reduces the frequency selective fading characteristic of the wireless channel.

A method includes receiving, by a first user device in a wireless network, an indication of availability of a pre-trained model that estimates a channel between a second user device and a network node; receiving, by the first user device, information relating to the pre-trained model; determining, by the first user device, channel estimation information based at least on the information relating to the pre-trained model; and performing at least one of the following: transmitting, by the first user device, a report to the network node including the channel estimation information; or receiving data, by the first user device from the network node, based on the channel estimation information.