A delay doppler domain transformation can be used to estimate characteristics of a channel between a base station and a user equipment or alternatively, between the user equipment and another user equipment. Thus, the velocity and the distance position of the user equipment can be calculated. For example, a signal received in the time-frequency domain, can be converted to the delay doppler domain by the base station. In response to the conversion, the base station can estimate the velocity of the user equipment. The velocity can be utilized by various applications. For example, the velocity can be utilized to alert the other user equipment to the location or an anticipated location of the user equipment.

An operation method of a transmitter in a communication system may comprise: configuring a first reference signal region for transmission of a first reference signal in the delay-Doppler domain; arranging the first reference signal having a sequence form in a specific region within the first reference signal region; transforming a delay-Doppler domain signal including the first reference signal into a time domain signal; and transmitting the time domain signal to a receiver.

Aspects of the subject disclosure may include, for example, obtaining channel cross correlation data relating to multiple user equipment (UEs) being served in a cell, wherein the channel cross correlation data comprises a correlation coefficient associated with a first UE of the multiple UEs and a second UE of the multiple UEs, identifying that the first UE is experiencing decreasing throughput, responsive to the identifying that the first UE is experiencing decreasing throughput, determining whether the correlation coefficient associated with the first UE and the second UE satisfies a correlation threshold, and, based on a first determination that the correlation coefficient does not satisfy the correlation threshold, adjusting a downlink (DL) transmit power allocation for transmissions directed to the first UE. Other embodiments are disclosed.

Methods, systems, and devices for wireless communications are described. A network entity may map a demodulation reference signal (DMRS), a truncated sequence, and data in a delay-Doppler domain in accordance with a control signal. The network entity may apply a Fourier transform on the mapped DMRS, the truncated sequence, and the data to generate a signal in the time domain. The network entity may output, and a user equipment (UE) may receive, the signal in the time domain, including the DMRS, the truncated sequence, and the data. The UE may apply a Fourier transform on the received signal in the time domain to generate a mapping of the DMRS and the data in the delay-Doppler domain. The UE may perform channel estimation based on applying the Fourier transform on the received signal.

Methods, systems, and devices for wireless communications are described. A user equipment (UE) may transmit, to a base station, capability signaling indicating one or more phase coherency capabilities of the UE for maintaining phase coherence across multiple uplink messages within a time interval, wherein each phase coherency capability is based on one or more channel usage characteristics associated with the time interval. The UE may receive, from the base station, a downlink message scheduling a set of uplink messages from the UE to the base station within the time interval. The UE may transmit the set of uplink messages within the time interval based on the downlink message and in accordance with at least one of the one or more phase coherency capabilities.

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.

A method for signal transmission using precoded symbol information involves estimating a two-dimensional model of a communication channel in a delay-Doppler domain. A perturbation vector is determined in a delay-time domain wherein the delay-time domain is related to the delay-Doppler domain by an FFT operation. User symbols are modified based upon the perturbation vector so as to produce perturbed user symbols. A set of Tomlinson-Harashima precoders corresponding to a set of fixed times in the delay-time domain may then be determined using a delay-time model of the communication channel. Precoded user symbols are generated by applying the Tomlinson-Harashima precoders to the perturbed user symbols. A modulated signal is then generated based upon the precoded user symbols and provided for transmission over the communication channel.

Fiber, cable, and wireless data channels are typically impaired by reflectors and other imperfections, producing a channel state with echoes and frequency shifts in data waveforms. Here, methods of using pilot symbol waveform bursts to automatically produce a detailed 2D model of the channel state are presented. This 2D channel state can then be used to optimize data transmission. For wireless data channels, an even more detailed 2D model of channel state can be produced by using polarization and multiple antennas in the process. Once 2D channel states are known, the system turns imperfect data channels from a liability to an advantage by using channel imperfections to boost data transmission rates. The methods can be used to improve legacy data transmission modes in multiple types of media, and are particularly useful for producing new types of robust and high capacity wireless communications using non-legacy data transmission methods as well.

Various aspects of the present disclosure generally relate to wireless communication. In some aspects, a wireless communication device may determine, based at least in part on two or more measurements on a channel taken at different points in time, that the channel is classified as static. The wireless communication device may perform at least one optimization based at least in part on determining that the channel is classified as static. For example, the at least one optimization may include modifying a channel state feedback procedure, reducing a periodicity associated with a measurement gap, modifying a filtering associated with measurements of the channel, reducing a threshold associated with beam switching, and/or refraining from performing at least one filtering at a radio frequency receiver of the wireless communication device. Numerous other aspects are described.

Apparatus, methods, and computer-readable media for facilitating phase jump estimation for SL DMRS bundling are disclosed herein. An example method includes receiving, from another device, first information at a first symbol of a first slot, the first slot including at least the first symbol and a first reference signal. The example method also includes receiving second information at a second symbol of a second slot, the second slot including at least the second symbol and a second reference signal, the first information and the second information being repetitions. The example method also includes generating a first reference signal copy based at least on the second reference signal and a phase jump between the first slot and the second slot. Additionally, the example method includes performing channel estimation across the first slot and the second slot based on an aggregation of the first reference signal and the first reference signal copy.