Qualcomm Incorporated

Shengbo Chen

Tao Luo

Makesh Pravin John Wilson

Sony Akkarakaran

Xiao Feng Wang

Wooseok Nam

Sumeeth Nagaraja

Kaushik Chakraborty

Juan Montojo

Yan Zhou

June Namgoong

Andrei Dragos Radulescu

Keiichi Kubota

Methods, systems, and devices for wireless communications are described. A base station may identify time and frequency resources for a physical downlink shared channel (PDSCH) to be transmitted to a user equipment (UE) in a first transmission time interval (TTI). The base station may transmit configuration information for a control channel search space set in a second TTI. The second TTI may precede the first TTI. The configuration information may include an indication of an absence of a physical downlink control channel (PDCCH) transmission to send in the control channel search space set indicating the identified time and frequency resources for the PDSCH, and a set of time and frequency resources for the control channel search space set. The UE may receive the configuration information and identify the time and frequency resources allocated for the PDSCH in the second TTI, and receive the PDSCH transmission in the second TTI.

Virtual search spaces for beam indication

Methods, systems, and devices for wireless communication are described. Wireless communications systems may support uplink random access channel (RACH) transmissions on multiple beams and over multiple component carriers (CCs). A wireless device may transmit a random access preamble to a base station in a first RACH transmission, which may indicate a set of CCs over which the base station may respond with a random access response (RAR) in a second RACH transmission. The second RACH transmission may then include an indication for which CCs the wireless device may use for a subsequent RACH transmission (e.g., a RACH message 3). The wireless device may also indicate a beam index and/or time-frequency resources associated with beams and/or CCs used for such cell acquisition transmissions. In other examples, the base station may indicate resources (e.g., via a handover command or RACH command) for wireless device scheduling request and/or beam-failure recovery request transmission.

Random access channel procedures with multiple carriers

Methods, systems, and devices for wireless communication are described. Wireless communications systems may support beamformed transmissions between devices (e.g., to improve coverage range). The beamformed transmissions may depend on discovery and maintenance of receive and transmit beams over which a given device may communicate with another device. Various receive and transmit beams for a given device may be compared using reference signals. As the number of devices attempting to access a cell increases, the number of reference signals to be transmitted may scale proportionally. Large numbers of reference signals may flood time-frequency resources of the system and/or require excessive processing at a mobile device. Scrambling sequences for reference signals may be employed to improve efficiency of resource usage. In aspects, the scrambling sequences may be implicitly determined (e.g., based on resources over which the access request was transmitted). Such an implicit association may reduce the need for additional signaling.

Sequence for reference signals during beam refinement

Certain aspects of the present disclosure generally relate to wireless communication. In some aspects, a UE may measure a first reference signal, associated with a frequency band of a long term evolution (LTE) system, and a second reference signal associated with a frequency band of a new radio (NR) system. The frequency band of the NR system may overlap the frequency band of the LTE system. The UE may determine first channel state feedback, associated with the frequency band of the LTE system, and second channel state feedback, associated with the frequency band of the NR system, based at least in part on the first reference signal and the second reference signal, respectively. The UE may report the first channel state feedback or the second channel state feedback in uplink control information (UCI). Other aspects are provided.

Techniques and apparatuses for nesting a new radio system and a long term evolution system

Methods, systems, and devices for wireless communications provide for transmission of a beam switch command to a user equipment (UE) via control channel signaling. The UE may establish a connection with a base station using a first transmission beam, receive configuration information configuring the UE to select between a first decoding hypothesis corresponding to downlink control information (DCI) including a bit field including a beam switch command and a second decoding hypothesis corresponding to the DCI not including the bit field, receive a downlink control channel transmission via the first transmission beam, decode the downlink control channel transmission in accordance with the configuration information to obtain decoded DCI, and communicate with the base station based at least in part on the decoded DCI.

Transmission of beam switch commands through control channel signaling

Certain aspects of the present disclosure relate to methods and apparatus for dynamic reclamation of resources reserved for forward compatibility using communications systems operating according to new radio (NR) technologies. Certain aspects provide a method for wireless communication. The method generally includes identifying resources previously reserved for forward compatibility (FC) that are available for reuse, and providing signaling, to one or more user equipments (UEs), indicating the identified resources are available for reuse.

Dynamic reclamation of resources reserved for forward compatibility

Certain aspects of the present disclosure provide techniques for selecting an uplink (UL) transmit beam by a user equipment (UE). A UE may receive, from a base station (BS), one or more beamformed downlink signals using one or more receive beams. The UE may select an uplink transmit beam based, at least in part, on the one or more beamformed downlink signals. The UE may transmit an uplink signal using the selected uplink transmit beam.

NR uplink transmit beam selection based on PDCCH/PDSCH receive beams

Certain aspects of the present disclosure generally relate to wireless communication. In some aspects, a user equipment (UE) may receive an indication of whether to use uplink reference signals or downlink reference signals for uplink precoder determination. The UE may selectively transmit a plurality of uplink reference signals or one or more measurement reports based at least in part on the indication, wherein the one or more measurement reports are determined based at least in part on measuring a plurality of downlink reference signals. The UE may receive an indication of a precoder, of a plurality of precoders, to be used to precode an uplink communication, wherein the precoder is identified based at least in part on the plurality of uplink reference signals or the one or more measurement reports. The UE may precode the uplink communication using the precoder. Numerous other aspects are provided.

Techniques and apparatuses for uplink precoder determination using downlink reference signals or downlink precoder determination using uplink reference signals

Techniques are described herein for beam pair link procedures used in dual connectivity operations. A master base station may be configured to determine a timing window for a user equipment (UE) to monitor a downlink channel associated with a secondary base station. In some cases, the master base station may determine the timing window during a dual connectivity procedure or during a carrier aggregation procedure. The UE may monitor the downlink channel during the timing window and establish a beam pair link with the secondary base station based on the monitoring.

Techniques for establishing a beam pair link

A base station may make more efficient use of resources by transmitting data in a control region of a slot in addition to a data region. In order to avoid performance loss, the base station may adjust the data transmission in the control region in comparison to a data transmission in a data region and may signal an indication to a UE to assist the UE in receiving the data transmission in the control region. An apparatus for wireless communication at the UE receives the indication from the base station regarding the data transmission in the control region and uses the indication to perform rate matching or demodulation of the data transmission in the control region. The indication may indicate any of a different MCS/rank/TPR, a reduced MCS/rank/TPR, an MCS/rank/TPR delta, a control span for a group of UEs, and a starting symbol for the data transmission. The indication may also indicate that there is no data transmitted on resources in the control region.

MCS/rank adjustment when multiplexing data in a control region

This disclosure generally relates to systems, devices, apparatuses, products, and methods for wireless communication. A communication system may include a user equipment (UE) that receives a configuration for contention-free random access (CFRA) and a configuration for contention-based random access (CBRA). The UE determines a first random access resource. The first random access resource maps to one or more beams from a target base station. The UE determines a beam quality associated with the first random access resource. The UE initiates a random access request using the CFRA when the first random access resource is a contention-free resource, and the beam quality of the first random access resource is above a threshold beam quality. The UE initiates the random access request using the CBRA when the first random access resource is the contention-free resource, and the beam quality of the first random access resource is below the threshold beam quality.

UE selection of contention-free and contention-based random access for handover

Aspects herein describe transmitting reference signals in wireless communications. An indication of resources over which to transmit an uplink reference signal can be received from an access point, where the resources are at least partially used by another device to transmit a downlink reference signal or a second uplink reference signal. The uplink reference signal can be transmitted over the resources.

Configuring reference signal transmission in wireless communications

A method of wireless communication includes receiving, at a user equipment (UE), a grant from a base station on a control channel, the grant including content indicating a mini-slot assigned to the UE. The method may include interpreting the grant based on a current configuration of a data channel to determine the mini-slot. The method may include communicating with the base station during the mini-slot indicated by the grant.

Variable-length transmission schemes

Wireless communications systems and methods related to reusing long-term evolution (LTE) resources for new radio (NR) system operations are provided. A UE receives, from a base station, a reference signal configuration of a first network of a long-term evolution (LTE) radio access technology (RAT). The UE and the base station are associated with a second network of another RAT. The reference signal configuration indicates at least a number of antenna ports associated with a reference signal of the first network. The UE determines a location of the reference signal associated with the reference signal configuration and receives, from the base station, a data signal of the second network based at least on the location of the reference signal of the first network.

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San Diego, CA, United States of America

Shengbo Chen