Abstract: Certain aspects of the present disclosure provide techniques for wireless communication by an apparatus. A method includes receiving a synchronization signal, the synchronization signal including timing information associated with a directional beam sweep procedure, and power threshold information indicating beam power criteria evaluated during the directional beam sweep procedure; receiving, from the directional beam sweep, a first directional beam in accordance with the timing information, the first directional beam providing radio frequency energy for energy harvesting by the apparatus; measuring an amount of power associated with the first directional beam; comparing the measured amount of power to the power threshold information; and providing a feedback signal, wherein the contents of the feedback signal are based on the comparison with the power threshold information associated with the directional beam sweep.

Abstract: Various aspects of the present disclosure generally relate to wireless communication. In some aspects, a phase sweeping procedure involves a first network node transmitting a first signal at a first phase while one or more second network nodes transmit a plurality of second signals at a plurality of second phases. In some aspects, the phase sweeping procedure may produce a plurality of combined signals, each combined signal a combination of the first signal and at least one of the plurality of second signals. For example, the first signal and the one or more second signals may constructively interfere with each other to produce a signal of sufficient energy to be received by an ambient internet of things (IoT) device. The ambient IoT device may transmit, to a network node, an indication of a received signal power associated with the combined signal.

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: Various aspects of the present disclosure generally relate to wireless communication. In some aspects, a first network entity may transmit, to a second network entity, a first random access communication including a random access preamble. The first network entity may receive, from the second network entity, a second random access communication including an identifier indicative of the random access preamble, and a first resource allocation. The first network entity may receive, from the second network entity, a third random access communication including the identifier, and indicating a second resource allocation. The first network entity may transmit, to the second network entity, a fourth random access communication via a particular resource allocation, wherein the particular resource is either the first resource allocation or the second resource allocation. Numerous other aspects are described.

Abstract: Methods, systems, and devices for wireless communications are described. A first wireless device (e.g., a network entity) may obtain, from multiple second wireless devices (e.g., user equipments (UEs)), multiple message segments via multiple slots. The first wireless device may assign each obtained message segment to a respective channel estimate cluster of multiple channel estimate clusters. A first set of the multiple message segments may be associated with a first channel estimate cluster, and may collectively form a first message. The first message may be associated with a second wireless device of the multiple second wireless devices. The first wireless device may decode the first message. In some examples, the first wireless device may decode a second message associated with a second channel estimate cluster of a second set of multiple message segments.

Abstract: Certain aspects of the present disclosure provide techniques for backscatter communications. An example method includes sending, to a first set of backscatter devices, one or more first signals via a first transmit beam at a first transmit power in one or more first transmission occasions; and sending, to a second set of backscatter devices, one or more second signals via a second transmit beam at a second transmit power in one or more second transmission occasions.

Abstract: Various aspects of the present disclosure generally relate to wireless communication. Some aspects more specifically relate to multiplexing ambient internet of things (IoT) waveforms and user equipment (UE) reference signals. In some aspects, a network node may transmit, to an ambient IoT device and a UE, an ambient IoT waveform multiplexed with a UE reference signal. For example, the network node may transmit the ambient IoT waveform multiplexed with the UE reference signal in accordance with various implementations for multiplexing the ambient IoT waveform with the UE reference signal.

Abstract: Various aspects of the present disclosure generally relate to wireless communication. In some aspects, a user equipment (UE) may transmit one or more requests to initiate transmission of a multiple-network-node power signal that uses a first network node and at least a second network node. The UE may receive the multiple-network-node power signal that uses the first network node and at least the second network node. Numerous other aspects are described.

Abstract: Methods, systems, and devices for wireless communications are described. A network entity may configure one or more random access channel (RACH) resource sets and a user equipment (UE) may receive a configuration message from the network entity. The configuration message may indicate multiple RACH resource sets for the UE. Each RACH resource set may be associated with a respective range of targeted uplink power values, with a respective quantity of random access occasions, with a respective RACH format, or a combination thereof. The UE may select a RACH resource set from the configured RACH resource sets based on an uplink power value associated with the UE. The UE may transmit one or more random access messages to the network entity in accordance with the selected RACH resource set.

Abstract: Methods, systems, and devices for wireless communications are described. A user equipment (UE) may use information related to a previously-transmitted random access preamble to determine whether a collision for the preamble exists, and the UE may transmit a subsequent random access message using resources selected in accordance with the determination. For example, the UE may receive a message that indicates path information for respective random access preambles detected by the network node. In some examples, the path information may indicate allocated resources for respective paths corresponding to the detected random access preambles. The UE may determine whether a collision exists for a path corresponding to the previously-transmitted random access preamble. The UE may transmit the subsequent random access message using a first set of resources (e.g., contention-based resources), a second set of resources (e.g.

Abstract: Various aspects of the present disclosure generally relate to wireless communication. Some aspects more specifically relate to ambient device random access message transmissions. A network node may transmit, and an ambient device may receive, configuration information that indicates a minimum permitted duration and a maximum permitted duration for transmitting a random access message. A reader device may transmit a query message to the ambient device. The ambient device may transmit, and the reader device may receive, a random access message that includes a pseudorandom noise sequence and a redundancy sequence. The redundancy sequence may include a portion of the pseudorandom noise sequence. A duration of the redundancy sequence may be in accordance with the minimum permitted duration and the maximum permitted duration. For example, the duration of the redundancy sequence may be equal to the maximum permitted duration subtracted by the minimum permitted duration.

Abstract: Various aspects of the present disclosure generally relate to wireless communication. In some aspects, a reader may transmit a first wireless communication signal to a first group of ambient internet of things (IoT) devices. The first group of ambient IoT devices may transmit a response to the signal based at least in part on being located within a first range of distances from the reader and the first signal being transmitted at a first transmit power. The reader may transmit a second wireless communication signal to a second group of ambient IoT devices. The second group of ambient IoT devices may transmit a response to the signal based at least in part on being located within a second range of distances from the reader and the signal being transmitted at a second transmit power. Numerous other aspects are described.

Abstract: This disclosure provides methods and apparatuses for maintaining phase continuity and optimizing channel estimation in wireless communication systems using multiple coherent demodulation reference signal (DMRS) ports through a glue reference signal (gRS). In various examples, an apparatus for wireless communication such as a UE or network entity may obtain or send, in a first time span, a first reference signal associated with multiple coherent ports in a code division multiplexing (CDM) group; obtain or send, in a second time span prior to the first time span, a second reference signal for compensation of a phase change across a gap between start and length indicator values (SLIVs) or within an SLIV; obtain or send, in the second time span, a third reference signal; and obtain or send a shared channel based on these signals. The methods and apparatuses provide enhanced phase continuity and accurate channel estimation, improving system performance and efficiency.

Abstract: Methods, systems, and devices for wireless communications are described. A user equipment (UE) may transmit a random access preamble via a random access occasion (RO) in accordance with a cyclic shift (CS) and a CS offset. The UE may receive, from a network entity, a first response message that indicates information associated with one or more random access paths detected by a network entity within a threshold duration. The UE may determine whether one or more collisions occur based on the information and may refrain from transmitting a random access message when two or more estimated random access paths are detected within a threshold duration of its CS and CS offset. The UE may receive a second response message based on refraining from transmitting the random access message. The UE may establish a connection with the network entity based on receiving the second response message.

Abstract: Techniques for collision resolution in Ambient Internet of Things (A-IoT) communications are described. A reader device obtains sampling frequency offset (SFO) indications for received random access messages and generates collision indicators based on the SFOs. The reader device may then allocate resources for subsequent transmissions using various strategies, such as omitting allocations for colliding devices, providing multiple allocations, or matching allocations to specific SFO values. A-IoT devices receive these allocations along with collision indicators and adjust their subsequent transmissions accordingly, either by selecting from multiple resources or generating new access sequences. This approach enables efficient collision handling while accommodating the limitations of low-complexity A-IoT devices.

Abstract: Various aspects of the present disclosure generally relate to wireless communication. In some aspects, a user equipment (UE) may receive a resource pool configuration associated with a plurality of resources in a resource pool and a plurality of demodulation reference signal (DMRS) parameter sets associated with each of the plurality of resources in the resource pool, wherein the plurality of DMRS parameter sets are associated with different transmit parameter values. The UE may select a resource from the plurality of resources in the resource pool. The UE may select a DMRS parameter set based on at least one transmit parameter value associated with a physical uplink shared channel (PUSCH) message. The UE may select a DMRS parameter from the selected DMRS parameter set. The UE may transmit a PUSCH message in the selected resource, wherein the PUSCH message includes the selected DMRS parameter. 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 transmit, to a network node, a physical random access channel (PRACH) message. The UE may receive, from the network node, a random access response (RAR) indicating a set of transmit power control (TPC) values. The UE may transmit, to the network node, a physical uplink shared channel (PUSCH) message using a TPC value selected from the set of TPC values. Numerous other aspects are described.

Abstract: Methods, systems, and devices for wireless communication are described. The techniques described herein relate to beam sweeping to improve the range of wireless power transfer. An energy harvesting user equipment (UE) receives, from a network entity, an indication of a set of time resources associated with a beam sweeping transmission (e.g., polling operation) by the network entity and one or more frequency shifts associated with backscattering the beam sweeping transmission. The UE receives the beam sweeping transmission from the network entity in accordance with the set of time resources. The UE transmits a backscattered signal based on the beam sweeping transmission and the one or more frequency shifts. The UE receives, from the network entity, a beamformed power signal in accordance with transmitting the backscattered signal. The UE stores energy for powering the UE based on the beamformed power signal.

Abstract: Methods, systems, and devices for wireless communications are described. The network may configure a contention-based resource pool for user equipments (UEs) to transmit uplink data with reduced signaling overhead. A UE may select to transmit an uplink message in a configured contention-based resource of the contention-based resource pool without receiving an uplink grant for the contention-based resource. Some uplink traffic types may have stricter delay budgets than other types of uplink traffic. A UE may select an uplink contention-based resource from a contention-based resource pool based on the delay status of an uplink data packet. The UE may determine a probability of accessing the uplink contention-based resource based on the remaining delay budget of the uplink packet. For example, the network may configure a function for the UE to determine the probability of accessing an uplink contention-based resource based on the delay status of a given uplink packet.

Abstract: Methods, systems, and devices for wireless communications are described. A user equipment (UE) may receive an indication of a self-scheduling resource pool associated with self-scheduling transmissions by the UE. The UE may encode, at a physical layer, data associated with a packet into a set of subpackets. Each subpacket of the set of subpackets may include a subset of the data and an identifier associated with the UE. The UE may transmit the set of subpackets via one or more resources of the self-scheduling resource pool.