Abstract: Aspects present herein relate to methods and devices for wireless communication including an apparatus, e.g., a UE and/or a base station. The apparatus may encode a plurality of bits associated with QAM, the plurality of bits corresponding to a circular buffer associated with at least one RV, the plurality of bits including a plurality of systematic bits. The apparatus may also transfer the plurality of bits from the circular buffer associated with the at least one RV to a first buffer and a second buffer. Additionally, the apparatus may map the plurality of bits from the first buffer and the second buffer to a plurality of modulation symbols.

Abstract: An apparatus may be configured to transmit (or receive) an indication of a first DMRS, where the first DMRS is identified based on at least two of a non-linearity of a power amplifier of the first device, a modulation and coding scheme (MCS) used for a data transmission associated with the first DMRS, or a channel type of a channel associated with the first DMRS; transmit (or receive), for a second device (or from a first device), the first DMRS for channel estimation at the second device; and transmit (or receive) the data transmission associated with the first DMRS.

Abstract: Certain aspects of the present disclosure provide techniques for delay-Doppler processing in orthogonal frequency domain multiplexing (OFDM). A method of wireless communication includes obtaining an indication of a first resource allocation associated with a first signal; obtaining the first signal in an OFDM resource grid based at least in part on the first resource allocation; and processing the first signal in a delay-Doppler domain.

Abstract: Various aspects of the present disclosure generally relate to wireless communication. In some aspects, a mobile station may receive, based at least in part on a time-frequency domain resource block that is characterized at least by a frequency span and a time duration, a wireless signal that comprises: a first modulated portion located in a first partition of the time-frequency domain resource block, the first modulated portion being based at least in part on an orthogonal time frequency space (OTFS) modulation scheme, and a second modulated portion located in a second partition of the time-frequency domain resource block, the second modulated portion being based at least in part on a second modulation scheme. The mobile station may recover a channel state information reference signal (CSI-RS) from the first modulated portion or the second modulated portion. Numerous other aspects are described.

Abstract: Methods, systems, and devices for wireless communications are described. A user equipment (UE) may receive first control signaling identifying a demodulation reference signal (DMRS) pattern that may be uniformly distributed in a time domain and a frequency domain. The DMRS pattern may include a first set of resource elements for the DMRS, a second set of resource elements for guard tones adjacent to and greater in frequency than the first set of resource elements, and a third set of resource elements for guard tones adjacent to and lower in frequency than the first set of resource elements. The UE may receive second control signaling that schedules a data signal to be communicated between the UE and a network node in a set of time-frequency resources. The UE may communicate the data signal according to the second control signaling and the DMRS according to the DMRS pattern.

Abstract: Methods, systems, and devices for wireless communication are described. In some wireless communications systems, a base station may transmit, to a user equipment (UE), an indication of a dynamic switch between slot formats. The base station and the UE may communicate first data in one or more first slots according to a first slot format. The first slot format may be a first cyclic prefix-based or guard interval-based slot format. The base station may transmit control signaling to the UE to indicate a second slot format different from the first slot format. The second slot format may be a second cyclic prefix-based or guard interval-based slot format. The UE and the base station may switch to communicating second data in one or more second slots in accordance with the second slot format based on the control signaling.

Abstract: Disclosed are techniques for wireless communication. In an aspect, a wireless device maps data, a unique word (UW) sequence, and a suppression signal to a set of reserved time-domain resources based on a time-domain resource mapping and reservation rule to produce DFT input data. DFT processing is performed on the DFT input data to produce IFFT input data. IFFT processing is performed on the IFFT input data to produce the GI-based waveform with a data part (e.g., non-zero part) and a tail part (e.g., zero tail part). The wireless device may further transmit the GI-based waveform.

Abstract: Apparatus, methods, and computer-readable media for facilitating multiplexing of time-varying DMRS within a symbol are disclosed herein. An example method for wireless communication at a receiving device includes receiving a first symbol of a single carrier waveform, the first symbol including a first set of DMRS resources. The example method also includes receiving a second symbol of the single carrier waveform, the second symbol including a second set of DMRS resources, the second set of DMRS resources associated with at least one of a DMRS starting location and a DMRS duration that is different than the first set of DMRS resources.

Abstract: Methods, systems, and devices for wireless communication are described to support guard interval (GI) configurations for multiple links. For example, a user equipment (UE) may determine a first GI duration for a first transmission reception point (TRP) and a second GI duration for a second TRP, when the UE is operating in a multi-TRP mode. The UE may determine the GI durations based on a difference in timing between signal reception from the first and second TRPs and may transmit a signal to one or both of the TRPs to indicate the GI durations. Based on the indicated GI durations, the first and second TRPs may transmit signaling to the UE that includes or implements the corresponding GI duration for each TRP. For example, the signaling may include a GI appended at the end of each symbol period that has a GI duration corresponding to the respective TRP.

Abstract: Methods, systems, and devices for wireless communications are described. A transmitting device, such as a network entity, may transmit an indication (e.g., via control signaling) to a receiving device, such as a user equipment (UE), indicating that a secure downlink message is scheduled for transmission to the UE. The UE may transmit a sounding reference signal (SRS) to the network entity in response to the control signaling, and the network entity may determine a channel estimate and construct interference based on the channel estimate. The network entity may encode the secure downlink message according to an orthogonal time frequency space (OTFS) precoding scheme and may add the interference to the encoded secure downlink message over a slot duration. The network entity may transmit the encoded secure downlink message, including the added interference, to the UE. The UE may decode the encoded secure downlink message based on the OTFS precoding scheme.

Abstract: Various aspects of the present disclosure generally relate to wireless communication. In some aspects, a user equipment (UE) or a base station may generate a discrete Fourier transform (DFT) waveform from separate DFT inputs of data content, a guard interval (GI) sequence, and tail suppression samples. The UE or the base station may generate a first communication with the DFT waveform using an inverse fast Fourier transform (IFFT) operation. The first communication may include, in a time domain, a data signal corresponding to the data content and a GI-based tail signal that corresponds to the GI sequence and that is suppressed with a tail suppression signal based at least in part on the tail suppression samples. The UE or the base station may transmit the first communication. Numerous other aspects are described.

Abstract: Methods, systems, and devices for wireless communication are described. A user equipment (UE) and a base station may communicate according to a combined cyclic prefix and guard interval-based waveform format. The base station may transmit control signaling to the UE. The control signaling may indicate a slot configuration. The UE may identify a format of a slot including a set of symbols based on the slot configuration. The format may indicate that a first portion of a first symbol of the set of symbols includes at least two cyclic prefixes and a second portion of the first symbol includes a guard interval. The UE and the base station may perform wireless communications during the first symbol in accordance with the format.

Abstract: Various aspects of the present disclosure generally relate to wireless communication. In some aspects, an integrated access and backhaul (IAB) node may receive, from a first wireless device, an uplink communication using a first guard interval. The IAB may receive, from a second wireless device, a downlink communication using a second guard interval, a second length of the second guard interval being different from a first length of the first guard interval. The IAB may process the uplink communication and the downlink communication in a same fast Fourier transform window. Numerous other aspects are described.

Abstract: The apparatus may be a device at a UE or a base station. The UE (or base station) may be configured to measure a phase noise of a first local oscillator associated with a first port. The UE (or base station) may further be configured to configure, based on the measured phase noise, an allocation of a first set of one or more REs of a PUSCH (or PDSCH) for at least one PT-RS associated with the first port. The first set of one or more REs may include multiple layers associated with a multiple-layer single-carrier waveform transmission. The UE (or base station) may also be configured to transmit, to a base station (or a UE), the PUSCH (or PDSCH) including the at least one PT-RS, the at least one PT-RS being transmitted via the configured allocation of the first set of one.

Abstract: Various aspects of the present disclosure generally relate to wireless communication. In some aspects, a first network node may apply an orthogonal time frequency space (OTFS) precoding to a plurality of tracking reference signal (TRS) resource samples allocated in a delay-Doppler domain to obtain a plurality of TRS symbols with the OTFS precoding. The first network node may transmit, to a second network node, a TRS in which the plurality of TRS symbols with the OTFS precoding have a uniform spacing in a time domain. Numerous other aspects are described.

Abstract: Certain aspects of the present disclosure provide techniques for time division multiplexing (TDMing) user equipment (UE) data using guard interval (GI)-based waveforms. An example method generally includes communicating with a device using a frame format, the frame format comprising a first symbol, a second symbol, and a third symbol, wherein: the first symbol comprises a first data portion for a first UE and a first GI corresponding to the first UE; the third symbol comprises a second data portion for a second UE and a second GI corresponding to the second UE, wherein the third symbol is later in time than the first symbol; and the second symbol comprises a gap or a reference signal (RS), a third GI corresponding to the first UE, and a fourth GI corresponding to the second UE, wherein the second symbol is between the first and third symbol in time.

Abstract: Various aspects of the present disclosure generally relate to wireless communication. In some aspects, a user equipment (UE) may precode a sounding reference signal (SRS) transmission using a delay-Doppler precoder. The UE may transmit, after precoding the SRS transmission using the delay-Doppler precoder, the SRS transmission in an SRS symbol in a slot. Numerous other aspects are described.

Abstract: Various aspects of the present disclosure generally relate to wireless communication. In some aspects, a user equipment (UE) may receive first configuration information indicating a first guard interval associated with sidelink communications. The UE may transmit, to a base station and another UE, a first sidelink communication using the first guard interval. The UE may transmit, to the base station and using a second guard interval having a second length that is different from a first length of the first guard interval, an uplink communication. Numerous other aspects are described.

Abstract: Methods, systems, and devices for wireless communications are described. A transmitting device may determine a phase noise profile and may transmit the phase noise profile to a receiving device. The receiving device may use the phase noise profile and received phase tracking reference signals to more accurately determine phase errors on a wireless channel between the two devices and compensate for the phase noise errors. In examples where the UE transmits the phase noise profile to the base station, the UE may include the phase noise profile in a measurement report or in a radio resource control (RRC) message, among other examples. In examples where the base station transmits the phase noise profile to a UE, the base station may include the phase noise profile in a broadcast message, a unicast message, or an RRC message.

Abstract: Methods, systems, and devices for wireless communications are described. A wireless device may generate a orthogonal time frequency space (OTFS) waveform for transmission to a second wireless device. Generation of an OTFS waveform may include mapping information samples to a delay-Doppler resource grid having a set of delay values and a set of Doppler values. A channel estimation block may occupy one or more rows of the delay-Doppler grid. When mapping information samples to the delay-Doppler grid, the transmitting device may first map information samples in the delay dimension (e.g., first map all of the symbols in one column of the delay-Doppler grid before mapping information samples into a second column). Such a mapping scheme may reduce the distance from any given information sample to the channel estimation block.