Abstract: Multi-band Wake-up (MWU) signal transmission and detection is disclosed. A transmitter determines a MWU signal that indicates availability of one or more sub-bands to a first user in a serving cell, and transmits the MWU signal for the one or more sub-bands in the serving cell. A clear channel assessment (CCA) status on the one or more sub-bands that are available to the first user is carried by the payload of MWU signals. The MWU signal includes a first user identifier that identifies the first user as a targeted receiver of the MWU signal. The first user has priority over a second user to utilize the one or more sub-bands. Correspondingly, a receiver receives a MWU signal for one or more sub-bands in the serving cell, decodes a payload of the MWU signal, and determines availability of the one or more sub-bands to the first user based on the payload of the MWU signal.

Abstract: Scheduling around frame based equipment (FBE) idle periods reduces the flexibility of scheduling and partitioning. This leads to a latency caused by waiting for the next downlink scheduling opportunity and skipping over unused uplink scheduling slots. According to certain aspects, to reduce overhead caused by idle time and ensure full downlink scheduling, a base station (BS) alternates between idle periods and channel occupancy time every fixed frame period with one or more other synchronized BSs, between components carriers of the BS, or both. Thus, a BS can always schedule downlink on a carrier during an idle period scheduled for a different BS and/or a different carrier.

Abstract: Various features related to eMTC-U deployment are described. In an aspect of the disclosure, an apparatus (e.g., a base station) maybe configured to select a subset of non-anchor channels from a set of available non-anchor channels, where the subset of non-anchor channels may correspond to a bandwidth within an unlicensed band. The apparatus maybe further configured to transmit information indicating the subset of non-anchor channels via an anchor channel. In some configurations, the subset of non-anchor channels maybe selected based on channel measurements performed by the base station or a UE. In one aspect, a UE may receive, from a base station via an anchor channel, information indicating a subset of non-anchor channels selected from a set of available non-anchor channels. The UE may transmit data on one or more non-anchor channel of the subset of non-anchor channels.

Abstract: Methods, systems, and devices for wireless communications are described. A user equipment (UE) may receive a discovery reference signal from a base station on an anchor channel. The UE may perform a first random or pseudorandom frequency hopping procedure to identify a plurality of downlink carriers for a first time period. The UE may perform a second random or pseudorandom frequency hopping procedure within the plurality of downlink carriers to select one of the plurality of downlink carriers as the uplink channel for a second time period. The UE may then transmit an uplink communication during the second time period on the selected uplink channel. In some examples, the uplink communication may be transmitted based at least in part on time division multiplexing (TDM) information.

Abstract: Aspects of the present disclosure provide a mechanism for improving reliability in a wireless communication network supporting a multi-cell transmission environment including a primary cell (PCell) and one or more secondary cells (SCells). In some examples, a user equipment (UE) in a connected mode with a PCell for multi-cell communication with the PCell and one or more SCells may utilize link quality measurements on both the PCell and one or more SCells to manage the connection with the PCell. In other examples, one or more SCells may function as a PCell to transmit common control signaling to the UE and/or receive uplink control information from the UE. In other examples, a UE in an idle mode may evaluate the reference signals transmitted from the PCell and one or more potential SCells before deciding whether to connect to the PCell for multi-cell communication.

Abstract: Methods, systems, and devices for wireless communications are described. In a wireless communications system, multiple transmission/reception points (TRPs) may perform a joint transmission to a user equipment (UE) such that the UE may rely on demodulation reference signals (DMRSs) from the TRPs for channel estimation and data demodulation to receive the joint transmission. When TRP transmissions are punctured, which may introduce reception errors at a receiving UE, one or more TRPs may transmit unique DMRSs such that each TRP transmits a DMRS that is unique to the transmitting TRP, transmit DMRSs that are unique to punctured resource elements (REs), or determine to refrain from transmitting on punctured REs. In some cases, TRPs may transmit preemption indications (PIs) to a UE, where the PIs may indicate punctured (e.g., or not utilized) REs to allow the UE to utilize a unique DMRS for channel estimation or to ignore the punctured REs.

Abstract: Methods, systems, and devices for wireless communications are described for multiplexing of uplink channels in a shared radio frequency spectrum band. Techniques may provide for segmenting uplink resources into multiple different sets of uplink resources, each set of uplink resources having one or more associated uplink control channel resources. A base station or user equipment (UE) may select a set of uplink resources from the multiple sets of uplink resources for uplink transmissions from the UE based on a location of the uplink control channel resources of the set of uplink resources relative to other allocated uplink resources of the UE. Uplink control information (UCI) may be multiplexed with one or more uplink shared channel transmissions of a UE for transmission to a base station in certain circumstances.

Abstract: Techniques and apparatus for enhancing uplink grant-free transmissions and/or downlink semi-persistent scheduling (SPS) transmissions for uplink ultra-reliable low latency communications (URLLC) are described. One technique includes receiving a first configuration for a first grant-free communication and a second configuration for at least one second grant-free communication. Grant-free communications are performed based on at least one of the first configuration or the second configuration.

Abstract: Wireless communications systems and methods related to on-demand cell coverage extension for broadcast signals are provided. A first wireless communication device communicates, with a second wireless communication device, a first extended cell coverage request. The first wireless communication device communicates, with the second wireless communication device, a first broadcast communication signal in an extended cell coverage mode in response to the first extended cell coverage request. The first broadcast communication signal includes a system information block repeated in at least one of a time domain or a frequency domain.

Abstract: Methods, systems, and devices for wireless communications are described. The method includes receiving a transmission from a first wireless device at a second wireless device, the transmission including a first coexistence preamble configured to reserve a channel of a shared radio frequency band for a first period of time, a first segment, and a second segment, where the first coexistence preamble comprises an initial channel reservation sequence and a data field indicating information about the first period of time; and transmitting, during a gap period between the first segment and the second segment, a receiver protection signal from the second wireless device, the receiver protection signal including a second coexistence preamble configured to reserve the channel of the shared radio frequency band for a second period of time associated with the second transmission segment.

Abstract: In various aspects, a base station and user equipment (UE) exchange an indication of UE capabilities and a monitoring schedule for the UE to monitor an integer M frequency band partitions for a predetermined signal. The base station performs one or more successful clear carrier assessments (CCAs) on an integer N frequency band partitions of the M frequency band partitions, wherein N<M, and maps one or more downlink transmissions to only the N frequency band partitions. Based on the mapping, the base station transmits the predetermined signal on only the N frequency band partitions, followed by a downlink signal during a transmission opportunity (TXOP). The UE cycles through the M frequency band partitions while monitoring for the predetermined signal according to the monitoring schedule, detects the predetermined signal on only the integer N frequency band partitions, and tunes to receive the downlink signal during the TXOP.

Abstract: Certain aspects of the present disclosure provide techniques for rate-matching data on a per transmission reception point (TRP) basis for single downlink control information (DCI) multi-TRP transmissions. Transmitters operating according to the present disclosure use a per TRP rate matching technique in which the rate-matching order is to first rate-match across spatial layers transmitted by a TRP, then across frequency, then across time, and then to another TRP, where remaining data is rate-matched across the spatial layers of that other TRP, then across frequency, and then across time. The described per TRP rate-matching technique causes code blocks of a transport block to be transmitted by one TRP, instead of each code block being transmitted by a group of TRPs.

Abstract: Over-the-air (OTA) dynamic time division duplex (TDD) is disclosed with a channel use indicator (CUI) receiver (CUI-R) signal multiplexed in uplink transmissions. According to various aspects, a user equipment (UE) may receive a downlink grant from a serving base station, in which the downlink grant identifies downlink transmissions in one or more subsequent communication slots. The UE may identify a trigger for transmission of a channel usage signal associated with the grant that may be received by neighboring UEs that may potentially interfere. The UE transmits the channel usage signal in a next scheduled uplink region and then receives downlink data from the serving base station according to the downlink grant. If the neighboring UE receives a conditional uplink grant, then it may proceed with uplink transmissions when it fails to detect the channel usage signal from the UE.

Abstract: Methods, systems, and devices for wireless communications are described that asynchronous carrier aggregation, including between high frequency band and lower frequency band transmissions. A user equipment (UE) may be configured to monitor transmissions in a first frequency band and a second frequency band. The UE may measure a timing difference between transmissions in the first frequency band and one or more of the transmissions in the second frequency band, and transmit an indication of the timing difference to a base station. The base station may use the timing difference to determine whether the UE is to use asynchronous carrier aggregation. If the base station determines that the UE is to use asynchronous carrier aggregation, the base station may configure the UE to observe at least a minimum amount of delay when conducting uplink signaling via one of the frequency bands.

Abstract: Methods, systems, and devices for wireless communications are described. A base station may perform a channel access procedure on a shared radio frequency spectrum band using a first beam configuration. The base station may transmit, based at least in part on successful completion of the channel access procedure, a reservation request message (RRQ) to a user equipment (UE) using a second beam configuration, the second beam configuration comprising a beam width that is equal to or narrower than a beam width of the first beam configuration. The base station may receive a reservation response message (RRS) from the UE in response to the RRQ, the RRS comprising a third beam configuration that is based at least in part on the second beam configuration.

Abstract: Aspects of the disclosure relate to synchronization signaling supporting multiple waveforms. A synchronization signal block (SSB) is configurable for transmission using either at least a first waveform or a second waveform, where the first waveform has higher peak to average power ratio (PAPR) characteristics such as OFDM and the second waveform has lower PAPR characteristics, such as DFT-S-OFDM. The SSB is transmitted selectively using either the first waveform or the second waveform for transmission of the SSB. Furthermore, the characteristics of the transmission such as a predetermined pattern of the first and second waveform transmissions may be utilized to communicate to a receiver the type of waveform being used. In this manner, SSB transmissions may take advantage of respective advantages afforded by each type of waveform, particularly when using higher frequency transmissions above 40 GHz in wireless communication systems.

Abstract: Methods, systems, and devices for wireless communication are described. A base station may perform a Listen-Before-Talk (LBT) procedure to obtain access to a wireless communication channel. The base station may then determine a pattern of synchronization signal block (SSB) transmissions based on an outcome of the LBT procedure and transmit the pattern of SSB transmissions after obtaining access to the wireless communication channel. The outcome of the LBT procedure may include obtaining access to the wireless communication channel after a missed opportunity for at least one SSB transmission in a discovery reference signal (DRS) measurement timing configuration (DMTC) window. A user equipment (UE) may determine system timing based on a received SSB transmission.

Abstract: Methods, systems, and devices for wireless communication are described. A base station may configure a system bandwidth of shared spectrum partitioned into a plurality of bandwidth parts based on interference associated with each of the plurality of bandwidth parts. The base station may then transmit the configuration of the system bandwidth to a plurality of devices. A UE may receive, from a base station, a configuration of a system bandwidth of shared spectrum. The system bandwidth may be partitioned into a plurality of bandwidth parts based on interference associated with each of the plurality of bandwidth parts. The UE may then communicate with the base station on at least one of the bandwidth parts.

Abstract: Methods, systems, and devices for wireless communications are described that provide for frame-based initiator device operations. A wireless device may be operating within a frame-based equipment communications system, where a frame may include a channel occupancy time period and a minimum idle period. An initiating device may be configured to initiate autonomous uplink communications during the channel occupancy time period of its frame, while the device may not initiate communications during an idle period of its frame. In some cases, a frame-based equipment communications system may include more than one initiating device, where the idle periods for different initiating devices may occur at different times. In some cases, the initiating device may be configured to initiate communications during the idle period for another initiating device. This may allow the wireless system to decrease system overhead associated with a minimum idle period per frame.

Abstract: Methods, systems, and devices for wireless communication are described. A base station may identify a first synchronization sequence and generate a second synchronization sequence based at least in part on the first synchronization sequence. The base station may map the first synchronization sequence to a first resource block of a synchronization channel associated with a first frequency sub-band of a shared radio frequency spectrum band and the second synchronization sequence to a second resource block associated with a second frequency sub-band of the synchronization channel. The base station may then transmit the first synchronization sequence and the second synchronization sequence concurrently over the synchronization channel using the first resource block and the second resource block according to the mapping. In some cases, the second synchronization may be generated by applying a first phase shift to the first synchronization sequence.