WO2021046832A1

WO2021046832A1 - Semi-static slot configuration for time division multiplexed uplink carriers

Info

Publication number: WO2021046832A1
Application number: PCT/CN2019/105813
Authority: WO
Inventors: Chenxi HAO; Bo Chen; Hao Xu; Yu Zhang; Chao Wei; Peter Gaal; Wanshi Chen
Original assignee: Qualcomm Incorporated
Priority date: 2019-09-13
Filing date: 2019-09-13
Publication date: 2021-03-18
Also published as: WO2021047293A1

Abstract

This disclosure provides systems, methods and apparatuses for semi-static slot configuration for time division multiplexed uplink carriers. Efficiency of configuring a slot pattern to be used on multiple uplink carriers may be improved by configuring one or more cell-specific slot patterns for each user equipment (UE) located in a cell associated with a base station and using UE-specific signaling to modify or activate a particular cell-specific slot pattern. Enabling a UE to switch among slot patterns further improves UE performance based on a location of the UE within the cell, such as by signaling the UE to operate according to a first slot pattern in which uplink slots are assigned to a higher frequency band to enable higher data rate transmissions at a cell center or according to a second slot pattern in which uplink slots are assigned to a lower frequency band to improve coverage at a cell edge.

Description

SEMI-STATIC SLOT CONFIGURATION FOR TIME DIVISION MULTIPLEXED UPLINK CARRIERS

TECHNICAL FIELD

Aspects of the present disclosure relate generally to wireless communication, and more particularly to techniques for semi-static slot configuration for time division multiplexed uplink carriers.

DESCRIPTION OF THE RELATED TECHNOLOGY

Wireless communication systems are widely deployed to provide various telecommunication services such as telephony, video, data, messaging, and broadcasts. Typical wireless communication systems may employ multiple-access technologies capable of supporting communication with multiple users by sharing available system resources (for example, bandwidth, transmit power, etc. ) . Examples of such multiple-access technologies include code division multiple access (CDMA) systems, time division multiple access (TDMA) systems, frequency-division multiple access (FDMA) systems, orthogonal frequency-division multiple access (OFDMA) systems, single-carrier frequency-division multiple access (SC-FDMA) systems, time division synchronous code division multiple access (TD-SCDMA) systems, and Long Term Evolution (LTE) . LTE/LTE-Advanced is a set of enhancements to the Universal Mobile Telecommunications System (UMTS) mobile standard promulgated by the Third Generation Partnership Project (3GPP) .

A wireless communication network may include a number of base stations (BSs) that can support communication for a number of user equipment (UEs) . A user equipment (UE) may communicate with a base station (BS) via the downlink (DL) and uplink (UL) . The DL (or forward link) refers to the communication link from the BS to the UE, and the UL (or reverse link) refers to the communication link from the UE to the BS. As will be described in more detail herein, a BS may be referred to as a NodeB, an LTE evolved nodeB (eNB) , a gNB, an access point (AP) , a radio head, a transmit receive point (TRP) , a New Radio (NR) BS, a 5G NodeB, or the like.

The above multiple access technologies have been adopted in various telecommunication standards to provide a common protocol that enables different UEs to communicate on a municipal, national, regional, and even global level. NR, which also may be referred to as 5G, is a set of enhancements to the LTE mobile standard promulgated by the Third Generation Partnership Project (3GPP) . NR is designed to better support mobile broadband Internet access by improving spectral efficiency, lowering costs, improving services, making use of new spectrum, and better integrating with other open standards using orthogonal frequency-division multiplexing (OFDM) with a cyclic prefix (CP) (CP-OFDM) on the DL, using CP-OFDM or SC-FDM (for example, also known as discrete Fourier transform spread OFDM (DFT-s-OFDM) ) on the UL (or a combination thereof) , as well as supporting beamforming, multiple-input multiple-output (MIMO) antenna technology, and carrier aggregation.

SUMMARY

The systems, methods, and devices of this disclosure each have several innovative aspects, no single one of which is solely responsible for the desirable attributes disclosed herein.

One innovative aspect of the subject matter described in this disclosure can be implemented in a method of wireless communication performed by a user equipment (UE) . The method may include receiving, from a base station, information configuring a slot pattern to be used for a first uplink carrier and a second uplink carrier that are time division multiplexed with one another, the slot pattern including a first set of uplink slots on the first uplink carrier and a second set of uplink slots on the second uplink carrier; and transmitting information to the base station on an uplink based at least in part on the slot pattern to be used for the first uplink carrier and the second uplink carrier.

In some aspects, receiving the information configuring the slot pattern for the first uplink carrier and the second uplink carrier may include receiving first signaling to indicate a default slot pattern including one or more slots that are scheduled for uplink communication on the first uplink carrier, and receiving second signaling to modify the default slot pattern to switch the one or more slots from being scheduled for uplink communication on the first uplink carrier to uplink communication on the second uplink carrier, where the slot pattern corresponds to the modified default slot pattern.

In some aspects, receiving the information configuring the slot pattern for the first uplink carrier and the second uplink carrier may include receiving signaling to indicate a default slot pattern including one or more slots that are scheduled for uplink communication on the first uplink carrier, and the slot pattern corresponds to the default slot pattern.

In some aspects, receiving the information configuring the slot pattern for the first uplink carrier and the second uplink carrier may include receiving first signaling to indicate multiple candidate slot patterns, each candidate slot pattern including a joint slot configuration for the first uplink carrier and the second uplink carrier, and receiving second signaling to activate one of the multiple candidate slot patterns as the slot pattern to be used for the first uplink carrier and the second uplink carrier.

In some aspects, the information configuring the slot pattern may include first signaling to indicate one or more cell-specific slot patterns for each UE in a cell associated with the base station, and second signaling that indicates the slot pattern that the particular UE is to use for the first uplink carrier and the second uplink carrier based at least in part on the one or more cell-specific slot patterns.

In some aspects, the first signaling may include a first radio resource control (RRC) message and the second signaling may include one or more of a second RRC message, a media access control (MAC) control element (MAC-CE) , or downlink control information (DCI) .

In some aspects, the method can include transmitting a measurement report to the base station, with the slot pattern to be used for the first uplink carrier and the second uplink carrier based at least in part on the measurement report.

In some aspects, the information configuring the slot pattern may include one or more bits to indicate an assignment of the first set of uplink slots and the second set of uplink slots among the first uplink carrier and the second uplink carrier.

In some aspects, communication on the uplink may be restricted on the second uplink carrier during one or more slots or symbols that correspond to the first set of uplink slots on the first uplink carrier.

Another innovative aspect of the subject matter described in this disclosure can be implemented in a UE for wireless communication. The UE may include a memory and one or more processors operatively coupled to the memory. The memory and the one or more processors may be configured to receive, from a base station, information configuring a slot pattern to be used for a first uplink carrier and a second uplink carrier that are time division multiplexed with one another, the slot pattern including a first set of uplink slots on the first uplink carrier and a second set of uplink slots on the second uplink carrier; and transmit information to the base station on an uplink based at least in part on the slot pattern to be used for the first uplink carrier and the second uplink carrier.

Another innovative aspect of the subject matter described in this disclosure can be implemented in a non-transitory computer-readable medium. The non-transitory computer-readable medium may store one or more instructions for wireless communication. The one or more instructions, when executed by one or more processors of a UE, may cause the one or more processors to receive, from a base station, information configuring a slot pattern to be used for a first uplink carrier and a second uplink carrier that are time division multiplexed with one another, the slot pattern including a first set of uplink slots on the first uplink carrier and a second set of uplink slots on the second uplink carrier; and transmit information to the base station on an uplink based at least in part on the slot pattern to be used for the first uplink carrier and the second uplink carrier.

Another innovative aspect of the subject matter described in this disclosure can be implemented in an apparatus for wireless communication. The apparatus may include means for means for receiving, from a base station, information configuring a slot pattern to be used for a first uplink carrier and a second uplink carrier that are time division multiplexed with one another, the slot pattern including a first set of uplink slots on the first uplink carrier and a second set of uplink slots on the second uplink carrier; and means for transmitting information to the base station on an uplink based at least in part on the slot pattern to be used for the first uplink carrier and the second uplink carrier.

Another innovative aspect of the subject matter described in this disclosure can be implemented in a method of wireless communication performed by a base station. The method may include transmitting, to a UE, information configuring a slot pattern to be used for a first uplink carrier and a second uplink carrier that are time division multiplexed with one another, the slot pattern including a first set of uplink slots on the first uplink carrier and a second set of uplink slots on the second uplink carrier; and receiving information transmitted by the UE on an uplink based at least in part on the slot pattern to be used for the first uplink carrier and the second uplink carrier.

In some aspects, transmitting the information configuring the slot pattern for the first uplink carrier and the second uplink carrier may include transmitting first signaling to indicate a default slot pattern including one or more slots that are scheduled for uplink communication on the first uplink carrier and transmitting second signaling to modify the default slot pattern to switch the one or more slots from being scheduled for uplink communication on the first uplink carrier to uplink communication on the second uplink carrier, with the slot pattern corresponding to the modified default slot pattern.

In some aspects, transmitting the information configuring the slot pattern for the first uplink carrier and the second uplink carrier may include transmitting signaling to indicate a default slot pattern including one or more slots that are scheduled for uplink communication on the first uplink carrier, with the slot pattern corresponding to the default slot pattern.

In some aspects, transmitting the information configuring the slot pattern for the first uplink carrier and the second uplink carrier may include transmitting first signaling to indicate multiple candidate slot patterns, each candidate slot pattern including a joint slot configuration for the first uplink carrier and the second uplink carrier, and transmitting second signaling to activate one of the multiple candidate slot patterns as the slot pattern to be used for the first uplink carrier and the second uplink carrier.

In some aspects, the first signaling may include a first RRC message and the second signaling may include one or more of a second RRC message, a MAC-CE, or DCI.

In some aspects, the method can include receiving a measurement report from the UE and determining the slot pattern to be used for the first uplink carrier and the second uplink carrier based at least in part on the measurement report.

Another innovative aspect of the subject matter described in this disclosure can be implemented in a base station for wireless communication. The base station may include a memory and one or more processors operatively coupled to the memory. The memory and the one or more processors may be configured to transmit, to a UE, information configuring a slot pattern to be used for a first uplink carrier and a second uplink carrier that are time division multiplexed with one another, the slot pattern including a first set of uplink slots on the first uplink carrier and a second set of uplink slots on the second uplink carrier; and receive information transmitted by the UE on an uplink based at least in part on the slot pattern to be used for the first uplink carrier and the second uplink carrier.

Another innovative aspect of the subject matter described in this disclosure can be implemented in a non-transitory computer-readable medium. The non-transitory computer-readable medium may store one or more instructions for wireless communication. The one or more instructions, when executed by one or more processors of a base station, may cause the one or more processors to transmit, to a UE, information configuring a slot pattern to be used for a first uplink carrier and a second uplink carrier that are time division multiplexed with one another, the slot pattern including a first set of uplink slots on the first uplink carrier and a second set of uplink slots on the second uplink carrier; and receive information transmitted by the UE on an uplink based at least in part on the slot pattern to be used for the first uplink carrier and the second uplink carrier.

Another innovative aspect of the subject matter described in this disclosure can be implemented in an apparatus for wireless communication. The apparatus may include means for means for transmitting, to a UE, information configuring a slot pattern to be used for a first uplink carrier and a second uplink carrier that are time division multiplexed with one another, the slot pattern including a first set of uplink slots on the first uplink carrier and a second set of uplink slots on the second uplink carrier; and means for receiving information transmitted by the UE on an uplink based at least in part on the slot pattern to be used for the first uplink carrier and the second uplink carrier.

Aspects generally include a method, apparatus, system, computer program product, non-transitory computer-readable medium, user equipment, base station, wireless communication device, or processing system as substantially described herein with reference to and as illustrated by the accompanying drawings.

Details of one or more implementations of the subject matter described in this disclosure are set forth in the accompanying drawings and the description below. Other features, aspects, and advantages will become apparent from the description, the drawings and the claims. Note that the relative dimensions of the following figures may not be drawn to scale.

BRIEF DESCRIPTION OF THE DRAWINGS

Figure 1 is a block diagram conceptually illustrating an example of a wireless network.

Figure 2 is a block diagram conceptually illustrating an example of a base station in communication with a UE in a wireless network.

Figure 3A is a block diagram conceptually illustrating an example of a frame structure in a wireless network.

Figure 3B is a block diagram conceptually illustrating an example synchronization signal (SS) hierarchy in a wireless network.

Figure 4 is a block diagram conceptually illustrating an example slot format with a normal cyclic prefix.

Figure 5 is a diagram conceptually illustrating an example of a downlink (DL) -centric slot.

Figure 6 is a diagram conceptually illustrating an example of an uplink (UL) -centric slot.

Figures 7A–7E are diagrams illustrating examples of semi-static slot configuration for time division multiplexed uplink carriers.

Figure 8 is a diagram illustrating an example process performed, for example, by a user equipment.

Figure 9 is a diagram illustrating an example process performed, for example, by a base station.

Like reference numbers and designations in the various drawings indicate like elements.

DETAILED DESCRIPTION

The following description is directed to certain implementations for the purposes of describing the innovative aspects of this disclosure. However, a person having ordinary skill in the art will readily recognize that the teachings herein can be applied in a multitude of different ways. Some of the examples in this disclosure are based on wireless and wired local area network (LAN) communication according to the Institute of Electrical and Electronics Engineers (IEEE) 802.11 wireless standards, the IEEE 802.3 Ethernet standards, and the IEEE 1901 Powerline communication (PLC) standards. However, the described implementations may be implemented in any device, system or network that is capable of transmitting and receiving radio frequency signals according to any of the wireless communication standards, including any of the IEEE 802.11 standards, the

standard, code division multiple access (CDMA) , frequency division multiple access (FDMA) , time division multiple access (TDMA) , Global System for Mobile communications (GSM) , GSM/General Packet Radio Service (GPRS) , Enhanced Data GSM Environment (EDGE) , Terrestrial Trunked Radio (TETRA) , Wideband-CDMA (W-CDMA) , Evolution Data Optimized (EV-DO) , 1xEV-DO, EV-DO Rev A, EV-DO Rev B, High Speed Packet Access (HSPA) , High Speed Downlink Packet Access (HSDPA) , High Speed Uplink Packet Access (HSUPA) , Evolved High Speed Packet Access (HSPA+) , Long Term Evolution (LTE) , AMPS, or other known signals that are used to communicate within a wireless, cellular or internet of things (IOT) network, such as a system utilizing 3G, 4G or 5G, or further implementations thereof, technology.

Time division multiplexing (TDM) techniques may be used in connection with an uplink carrier aggregation mode to enable a UE to perform uplink transmission across multiple component carriers. For example, the multiple component carriers may include a primary uplink carrier and one or more secondary uplink carriers, and a TDM pattern may be defined such that the UE can transmit on only one uplink carrier at a time (such as in a particular symbol or slot) . In some cases, TDM techniques may be used in connection with the uplink carrier aggregation mode because certain bands operating at high frequencies may have a shorter coverage range compared to other bands operating at relatively lower frequencies (such as the 3.5 gigahertz (GHz) frequency band operating in time division duplexing (TDD) mode exhibiting about 9 decibels (dB) coverage loss, compared to the 2.1 GHz band, which includes an uplink frequency band that is paired with a downlink frequency band operating in frequency division duplexing (FDD) mode) . For example, carrier aggregation techniques that support concurrent or simultaneous transmission via multiple component carriers are associated with bottlenecks due to increased UE implementation complexity because the UE has to operate on multiple frequencies simultaneously. Furthermore, in carrier aggregation techniques that support concurrent or simultaneous transmission, the UE can only use one transmit antenna in each frequency band, creating further bottlenecks.

Accordingly, in some cases, TDM techniques can be implemented in connection with uplink carrier aggregation to enable support for multiple transmit antennas in a high-frequency band (such as the 3.5 GHz frequency band) and a single transmit antenna in a low-frequency band (such as the 2.1 GHz frequency band) because there are no simultaneous transmissions on different frequency bands. Furthermore, TDM techniques may allow a network to schedule UEs in a manner that may improve utilization of network resources. For example, different TDM patterns may be configured based on the location of a UE within a cell. For example, a UE located near an edge of a cell associated with a base station may be scheduled on the low band to increase coverage. For another example, in some uplink slots, a UE located near the center or median of the cell may be scheduled on the high band to exploit the larger available bandwidth on the high band, and in other uplink slots, the UE located near the center or median of the cell may be scheduled on the low band to enable fast hybrid automatic repeat request acknowledgement (HARQ-ACK) feedback as there may be more uplink resources available in the low band.

In general, TDM for uplink carriers may be implemented in a supplemental uplink (SUL) mode or in a TDM carrier aggregation mode. For example, in the SUL mode, a UE may be configured with two uplink carriers (such as a TDD carrier and an SUL carrier) and one downlink carrier (such as the TDD carrier) , and the UE may be permitted to operate on only one uplink carrier at a time (such as in a particular symbol or slot) . Furthermore, in the SUL mode, the UE can be scheduled for uplink transmission on either uplink carrier in an arbitrary symbol or slot. Accordingly, the SUL mode can support one transmit antenna on each uplink carrier with substantially no switching time between uplink carriers, or the SUL mode can support two transmit antennas on the primary uplink carrier (such as the TDD carrier) and one transmit antenna on the SUL carrier, with a small switching time between carriers (such as 35, 70, or 140 microseconds) . Notably, however, the SUL mode can only be configured in a co-sited case, where both uplink carriers are from the base station because there is only one downlink carrier. In the TDM carrier aggregation mode, the UE may be configured with two uplink carriers (such as a TDD carrier and an FDD uplink carrier) and two downlink carriers (such as the TDD carrier and an FDD downlink carrier paired with the FDD uplink carrier) , and the UE may be permitted to operate on only one uplink carrier at a time, according to a semi-static or dynamic TDM pattern. In this case, because there are two downlink carriers, each uplink carrier may be associated with a different reference downlink carrier (such as for indicating a timing advance (TA) or power control to be used on the corresponding uplink carrier) . Accordingly, the TDM carrier aggregation mode offers better performance (such as more flexible power control or increased reliability, compared to SUL, because there are two downlink carriers) and more flexible deployment because TDM carrier aggregation can be implemented in co-sited or distributed base station architectures.

Although implementing TDM techniques in connection with uplink carrier aggregation (whether in SUL mode or TDM carrier aggregation mode) offers better performance in various respects relative to carrier aggregation techniques that enable concurrent transmission via multiple uplink carriers, implementing TDM techniques for multiple uplink carriers poses various challenges. For example, enabling dynamic switching between uplink carriers (such as between different TDM patterns for UEs located at a cell center and UEs located at a cell edge) increases UE complexity because the UE does not know which uplink carrier or which slots the base station will use to schedule uplink transmissions until the UE receives an uplink grant. To address these issues, a semi-static uplink slot configuration (or slot pattern) may enable the UE to determine, in advance, when to switch between uplink carriers. For example, in some cases, a first TDM pattern defined for cell center UEs may assign one or more uplink slots to an uplink carrier operating at a higher frequency, to enable the UE to perform high rate transmissions, and other uplink slots may be assigned to the uplink carrier operating at the lower frequency to enable fast HARQ-ACK feedback for downlink data transmitted on the higher frequency band. Furthermore, a second TDM pattern defined for cell edge UEs may assign one or more uplink slots to the uplink carrier operating at the lower frequency to address coverage issues. Accordingly, some aspects described herein provide techniques and apparatuses for configuring multiple slot patterns (or TDM patterns) and causing a UE to switch among the slot patterns.

Particular implementations of the subject matter described in this disclosure can be implemented to realize one or more of the following potential advantages. In some aspects, the techniques and apparatuses described herein improve efficiency of configuring a slot pattern that a UE is to use to perform uplink transmissions on a first uplink carrier and a second uplink carrier by configuring one or more cell-specific slot patterns for all UEs located in a cell associated with a base station and using UE-specific signaling to modify or activate a particular cell-specific slot pattern. The techniques and apparatuses described herein provide the further advantage of enabling a UE to operate according to a particular slot pattern that improves performance of the UE based on a location of the UE within the cell (such as by signaling the UE to operate according to a slot pattern in which uplink slots are assigned to a higher frequency band to enable higher data rate transmissions at a cell center or by signaling the UE to operate according to a slot pattern in which uplink slots are assigned to a lower frequency band to improve coverage at a cell edge) .

Figure 1 is a block diagram conceptually illustrating an example of a wireless network 100. The wireless network 100 may be an LTE network or some other wireless network, such as a 5G or NR network. Wireless network 100 may include a number of BSs 110 (shown as BS 110a, BS 110b, BS 110c, and BS 110d) and other network entities. A BS is an entity that communicates with user equipment (UEs) and also may be referred to as a base station, a NR BS, a Node B, a gNB, a 5G node B (NB) , an access point, a transmit receive point (TRP) , or the like. Each BS may provide communication coverage for a particular geographic area. In 3GPP, the term “cell” can refer to a coverage area of a BS, a BS subsystem serving this coverage area, or a combination thereof, depending on the context in which the term is used.

A BS may provide communication coverage for a macro cell, a pico cell, a femto cell, another type of cell, or a combination thereof. A macro cell may cover a relatively large geographic area (for example, several kilometers in radius) and may allow unrestricted access by UEs with service subscription. A pico cell may cover a relatively small geographic area and may allow unrestricted access by UEs with service subscription. A femto cell may cover a relatively small geographic area (for example, a home) and may allow restricted access by UEs having association with the femto cell

(for example, UEs in a closed subscriber group (CSG) ) . A BS for a macro cell may be referred to as a macro BS. A BS for a pico cell may be referred to as a pico BS. A BS for a femto cell may be referred to as a femto BS or a home BS. In the example shown in Figure 1, a BS 110a may be a macro BS for a macro cell 102a, a BS 110b may be a pico BS for a pico cell 102b, and a BS 110c may be a femto BS for a femto cell 102c. A BS may support one or multiple (for example, three) cells. The terms “eNB” , “base station” , “NR BS” , “gNB” , “TRP” , “AP” , “node B” , “5G NB” , and “cell” may be used interchangeably herein.

In some examples, a cell may not necessarily be stationary, and the geographic area of the cell may move according to the location of a mobile BS. In some examples, the BSs may be interconnected to one another as well as to one or more other BSs or network nodes (not shown) in the wireless network 100 through various types of backhaul interfaces, such as a direct physical connection, a virtual network, or a combination thereof using any suitable transport network.

Wireless network 100 also may include relay stations. A relay station is an entity that can receive a transmission of data from an upstream station (for example, a BS or a UE) and send a transmission of the data to a downstream station (for example, a UE or a BS) . A relay station also may be a UE that can relay transmissions for other UEs. In the example shown in Figure 1, a relay station 110d may communicate with macro BS 110a and a UE 120d in order to facilitate communication between BS 110a and UE 120d. A relay station also may be referred to as a relay BS, a relay base station, a relay, etc.

Wireless network 100 may be a heterogeneous network that includes BSs of different types, for example, macro BSs, pico BSs, femto BSs, relay BSs, etc. These different types of BSs may have different transmit power levels, different coverage areas, and different impacts on interference in wireless network 100. For example, macro BSs may have a high transmit power level (for example, 5 to 40 Watts) whereas pico BSs, femto BSs, and relay BSs may have lower transmit power levels (for example, 0.1 to 2 Watts) .

A network controller 130 may couple to a set of BSs and may provide coordination and control for these BSs. Network controller 130 may communicate with the BSs via a backhaul. The BSs also may communicate with one another, for example, directly or indirectly via a wireless or wireline backhaul.

UEs 120 (for example, 120a, 120b, 120c) may be dispersed throughout wireless network 100, and each UE may be stationary or mobile. A UE also may be referred to as an access terminal, a terminal, a mobile station, a subscriber unit, a station, etc. A UE may be a cellular phone (for example, a smart phone) , a personal digital assistant (PDA) , a wireless modem, a wireless communication device, a handheld device, a laptop computer, a cordless phone, a wireless local loop (WLL) station, a tablet, a camera, a gaming device, a netbook, a smartbook, an ultrabook, a medical device or equipment, biometric sensors/devices, wearable devices (smart watches, smart clothing, smart glasses, smart wrist bands, smart jewelry (for example, smart ring, smart bracelet) ) , an entertainment device (for example, a music or video device, or a satellite radio) , a vehicular component or sensor, smart meters/sensors, industrial manufacturing equipment, a global positioning system device, or any other suitable device that is configured to communicate via a wireless or wired medium.

Some UEs may be considered machine-type communication (MTC) or evolved or enhanced machine-type communication (eMTC) UEs. MTC and eMTC UEs include, for example, robots, drones, remote devices, sensors, meters, monitors, location tags, etc., that may communicate with a base station, another device (for example, remote device) , or some other entity. A wireless node may provide, for example, connectivity for or to a network (for example, a wide area network such as Internet or a cellular network) via a wired or wireless communication link. Some UEs may be considered Internet-of-Things (IoT) devices or may be implemented as NB-IoT

(narrowband internet of things) devices. Some UEs may be considered a Customer Premises Equipment (CPE) . UE 120 may be included inside a housing that houses components of UE 120, such as processor components, memory components, similar components, or a combination thereof.

In general, any number of wireless networks may be deployed in a given geographic area. Each wireless network may support a particular RAT and may operate on one or more frequencies. A RAT also may be referred to as a radio technology, an air interface, etc. A frequency also may be referred to as a carrier, a frequency channel, etc. Each frequency may support a single RAT in a given geographic area in order to avoid interference between wireless networks of different RATs. In some cases, NR or 5G RAT networks may be deployed.

In some examples, access to the air interface may be scheduled, where a scheduling entity (for example, a base station) allocates resources for communication among some or all devices and equipment within the scheduling entity’s service area or cell. Within the present disclosure, as discussed further below, the scheduling entity may be responsible for scheduling, assigning, reconfiguring, and releasing resources for one or more subordinate entities. That is, for scheduled communication, subordinate entities utilize resources allocated by the scheduling entity.

Base stations are not the only entities that may function as a scheduling entity. That is, in some examples, a UE may function as a scheduling entity, scheduling resources for one or more subordinate entities (for example, one or more other UEs) . In this example, the UE is functioning as a scheduling entity, and other UEs utilize resources scheduled by the UE for wireless communication. A UE may function as a scheduling entity in a peer-to-peer (P2P) network, in a mesh network, or another type of network. In a mesh network example, UEs may optionally communicate directly with one another in addition to communicating with the scheduling entity.

Thus, in a wireless communication network with a scheduled access to time–frequency resources and having a cellular configuration, a P2P configuration, and a mesh configuration, a scheduling entity and one or more subordinate entities may communicate utilizing the scheduled resources.

In some aspects, two or more UEs 120 (for example, shown as UE 120a and UE 120e) may communicate directly using one or more sidelink channels (for example, without using a base station 110 as an intermediary to communicate with one another) . For example, the UEs 120 may communicate using peer-to-peer (P2P) communications, device-to-device (D2D) communications, a vehicle-to-everything (V2X) protocol (which may include a vehicle-to-vehicle (V2V) protocol, a vehicle-to-infrastructure (V2I) protocol, or similar protocol) , a mesh network, or similar networks, or combinations thereof. In this case, the UE 120 may perform scheduling operations, resource selection operations, as well as other operations described elsewhere herein as being performed by the base station 110.

Figure 2 is a block diagram conceptually illustrating an example 200 of a base station 110 in communication with a UE 120. In some aspects, base station 110 and UE 120 may respectively be one of the base stations and one of the UEs in wireless network 100 of Figure 1. Base station 110 may be equipped with T antennas 234a through 234t, and UE 120 may be equipped with R antennas 252a through 252r, where in general T ≥ 1 and R ≥ 1.

At base station 110, a transmit processor 220 may receive data from a data source 212 for one or more UEs, select one or more modulation and coding schemes (MCS) for each UE based at least in part on channel quality indicators (CQIs) received from the UE, process (for example, encode and modulate) the data for each UE based at least in part on the MCS (s) selected for the UE, and provide data symbols for all UEs. The transmit processor 220 also may process system information (for example, for semi-static resource partitioning information (SRPI) , etc. ) and control information (for example, CQI requests, grants, upper layer signaling, etc. ) and provide overhead symbols and control symbols. The transmit processor 220 also may generate reference symbols for reference signals (for example, the cell-specific reference signal (CRS) ) and synchronization signals (for example, the primary synchronization signal (PSS) and secondary synchronization signal (SSS) ) . A transmit (TX) multiple-input multiple-output (MIMO) processor 230 may perform spatial processing (for example, precoding) on the data symbols, the control symbols, the overhead symbols, or the reference symbols, if applicable, and may provide T output symbol streams to T modulators (MODs) 232a through 232t. Each modulator 232 may process a respective output symbol stream (for example, for OFDM, etc. ) to obtain an output sample stream. Each modulator 232 may further process (for example, convert to analog, amplify, filter, and upconvert) the output sample stream to obtain a downlink signal. T downlink signals from modulators 232a through 232t may be transmitted via T antennas 234a through 234t, respectively. According to various aspects described in more detail below, the synchronization signals can be generated with location encoding to convey additional information.

At UE 120, antennas 252a through 252r may receive the downlink signals from base station 110 or other base stations and may provide received signals to demodulators (DEMODs) 254a through 254r, respectively. Each demodulator 254 may condition (for example, filter, amplify, downconvert, and digitize) a received signal to obtain input samples. Each demodulator 254 may further process the input samples (for example, for OFDM, etc. ) to obtain received symbols. A MIMO detector 256 may obtain received symbols from all R demodulators 254a through 254r, perform MIMO detection on the received symbols if applicable, and provide detected symbols. A receive processor 258 may process (for example, demodulate and decode) the detected symbols, provide decoded data for UE 120 to a data sink 260, and provide decoded control information and system information to a controller or processor (controller/processor) 280. A channel processor may determine reference signal received power (RSRP) , received signal strength indicator (RSSI) , reference signal received quality (RSRQ) , channel quality indicator (CQI) , etc. In some aspects, one or more components of UE 120 may be included in a housing.

On the uplink, at UE 120, a transmit processor 264 may receive and process data from a data source 262 and control information (for example, for reports including RSRP, RSSI, RSRQ, CQI, etc. ) from controller/processor 280. Transmit processor 264 also may generate reference symbols for one or more reference signals. The symbols from transmit processor 264 may be precoded by a TX MIMO processor 266 if applicable, further processed by modulators 254a through 254r (for example, for DFT-s- OFDM, CP-OFDM, etc. ) , and transmitted to base station 110. At base station 110, the uplink signals from UE 120 and other UEs may be received by antennas 234, processed by demodulators 232, detected by a MIMO detector 236 if applicable, and further processed by a receive processor 238 to obtain decoded data and control information sent by UE 120. Receive processor 238 may provide the decoded data to a data sink 239 and the decoded control information to a controller or processor (i.e., controller/processor) 240. The base station 110 may include communication unit 244 and communicate to network controller 130 via communication unit 244. The network controller 130 may include communication unit 294, a controller or processor (i.e., controller/processor) 290, and memory 292.

The controller/processor 240 of base station 110, the controller/processor 280 of UE 120, or any other component (s) of Figure 2 may perform one or more techniques associated with semi-static slot configuration for time division multiplexed uplink carriers, as described in more detail elsewhere herein. For example, the controller/processor 240 of base station 110, the controller/processor 280 of UE 120, or any other component (s) (or combinations of components) of Figure 2 may perform or direct operations of, for example, the process 800 of Figure 8, the process 900 of Figure 9, or other processes as described herein. The

memories

242 and 282 may store data and program codes for base station 110 and UE 120, respectively. A scheduler 246 may schedule UEs for data transmission on the downlink, the uplink, or a combination thereof.

The stored program codes, when executed by the controller/processor 280 or other processors and modules at UE 120, may cause the UE 120 to perform operations described with respect to the process 800 of Figure 8 or other processes as described herein. The stored program codes, when executed by the controller/processor 240 or other processors and modules at base station 110, may cause the base station 110 to perform operations described with respect to the process 900 of Figure 9 or other processes as described herein. A scheduler 246 may schedule UEs for data transmission on the downlink, the uplink, or a combination thereof.

In some aspects, UE 120 may include means for receiving, from the base station 110, information configuring a slot pattern to be used for a first uplink carrier and a second uplink carrier that are time division multiplexed with one another, the slot pattern including a first set of uplink slots on the first uplink carrier and a second set of uplink slots on the second uplink carrier, means for transmitting information to the base station 110 on an uplink based at least in part on the slot pattern to be used for the first uplink carrier and the second uplink carrier, or the like, or combinations thereof. In some aspects, such means may include one or more components of UE 120 described in connection with Figure 2.

In some aspects, base station 110 may include means for transmitting, to the UE 120, information configuring a slot pattern to be used for a first uplink carrier and a second uplink carrier that are time division multiplexed with one another, the slot pattern including a first set of uplink slots on the first uplink carrier and a second set of uplink slots on the second uplink carrier, means for receiving information transmitted by the UE 120 on an uplink based at least in part on the slot pattern to be used for the first uplink carrier and the second uplink carrier, or the like, or combinations thereof. In some aspects, such means may include one or more components of base station 110 described in connection with Figure 2.

While blocks in Figure 2 are illustrated as distinct components, the functions described above with respect to the blocks may be implemented in a single hardware, software, or combination component or in various combinations of components. For example, the functions described with respect to the transmit processor 264, the receive processor 258, the TX MIMO processor 266, or another processor may be performed by or under the control of controller/processor 280.

Figure 3A is a block diagram conceptually illustrating an example frame structure 300 in a wireless network. In some aspects, frame structure 300 may be for FDD in the wireless network, which may include a 5G NR wireless network or another type of wireless network. The transmission timeline for each of the downlink and uplink may be partitioned into units of radio frames (sometimes referred to as frames) . Each radio frame may have a predetermined duration (for example, 10 milliseconds (ms) ) and may be partitioned into a set of Z (Z ≥ 1) subframes (for example, with indices of 0 through Z-1) . Each subframe may have a predetermined duration (for example, 1 ms) and may include a set of slots (for example, 2 ^m slots per subframe are shown in Figure 3A, where m is a numerology used for a transmission, such as 0, 1, 2, 3, 4, or the like) . Each slot may include a set of L symbol periods. For example, each slot may include fourteen symbol periods (for example, as shown in Figure 3A) , seven symbol periods, or another number of symbol periods. In a case where the subframe includes two slots (for example, when m = 1) , the subframe may include 2L symbol periods, where the 2L symbol periods in each subframe may be assigned indices of 0 through 2L–1. In some aspects, a scheduling unit for the FDD may frame-based, subframe-based, slot-based, symbol-based, or the like.

While some techniques are described herein in connection with frames, subframes, slots, or the like, these techniques may equally apply to other types of wireless communication structures, which may be referred to using terms other than “frame, ” “subframe, ” “slot, ” or the like in 5G NR. In some aspects, a wireless communication structure may refer to a periodic time-bounded communication unit defined by a wireless communication standard or protocol. Additionally, or alternatively, different configurations of wireless communication structures than those shown in Figure 3A may be used.

In certain telecommunications (for example, NR) , a base station may transmit synchronization signals. For example, a base station may transmit a primary synchronization signal (PSS) , a secondary synchronization signal (SSS) , or the like, on the downlink for each cell supported by the base station. The PSS and SSS may be used by UEs for cell search and acquisition. For example, the PSS may be used by UEs to determine symbol timing, and the SSS may be used by UEs to determine a physical cell identifier, associated with the base station, and frame timing. The base station also may transmit a physical broadcast channel (PBCH) . The PBCH may carry some system information, such as system information that supports initial access by UEs.

In some aspects, the base station may transmit the PSS, the SSS, the PBCH, or a combination thereof in accordance with a synchronization communication hierarchy (for example, a synchronization signal (SS) hierarchy) including multiple synchronization communications (for example, SS blocks) , as described below in connection with Figure 3B.

Figure 3B is a block diagram conceptually illustrating an example SS hierarchy in a wireless network. In some aspects, the example SS hierarchy may be an example of a synchronization communication hierarchy. As shown in Figure 3B, the SS hierarchy may include an SS burst set, which may include a plurality of SS bursts (identified as SS burst 0 through SS burst B-1, where B is a maximum number of repetitions of the SS burst that may be transmitted by the base station) . As further shown, each SS burst may include one or more SS blocks (identified as SS block 0 through SS block (b _{max_SS}-1) , where b _{max_SS}-1 is a maximum number of SS blocks that can be carried by an SS burst) . In some aspects, different SS blocks may be beam-formed differently. An SS burst set may be periodically transmitted by a wireless node, such as every X milliseconds, as shown in Figure 3B. In some aspects, an SS burst set may have a fixed or dynamic length, shown as Y milliseconds in Figure 3B.

The SS burst set shown in Figure 3B is an example of a synchronization communication set, and other synchronization communication sets may be used in connection with the techniques described herein. Furthermore, the SS block shown in Figure 3B is an example of a synchronization communication, and other synchronization communications may be used in connection with the techniques described herein.

In some aspects, an SS block includes resources that carry the PSS, the SSS, the PBCH, or other synchronization signals (for example, a tertiary synchronization signal (TSS) ) or synchronization channels. In some aspects, multiple SS blocks are included in an SS burst, and the PSS, the SSS, or the PBCH may be the same across each SS block of the SS burst. In some aspects, a single SS block may be included in an SS burst. In some aspects, the SS block may be at least four symbol periods in length, where each symbol carries one or more of the PSS (for example, occupying one symbol) , the SSS (for example, occupying one symbol) , or the PBCH (for example, occupying two symbols) .

In some aspects, the symbols of an SS block are consecutive, as shown in Figure 3B. In some aspects, the symbols of an SS block are non-consecutive. Similarly, in some aspects, one or more SS blocks of the SS burst may be transmitted in consecutive radio resources (for example, consecutive symbol periods) during one or more slots. Additionally, or alternatively, one or more SS blocks of the SS burst may be transmitted in non-consecutive radio resources.

In some aspects, the SS bursts may have a burst period, whereby the SS blocks of the SS burst are transmitted by the base station according to the burst period. In other words, the SS blocks may be repeated during each SS burst. In some aspects, the SS burst set may have a burst set periodicity, whereby the SS bursts of the SS burst set are transmitted by the base station according to the fixed burst set periodicity. In other words, the SS bursts may be repeated during each SS burst set.

The base station may transmit system information, such as system information blocks (SIBs) on a physical downlink shared channel (PDSCH) in certain slots. The base station may transmit control information/data on a physical downlink control channel (PDCCH) in C symbol periods of a slot, where B may be configurable for each slot. The base station may transmit traffic data or other data on the PDSCH in the remaining symbol periods of each slot.

Figure 4 is a block diagram conceptually illustrating an example slot format 410 with a normal cyclic prefix. The available time frequency resources may be partitioned into resource blocks. Each resource block may cover a set of subcarriers (for example, 12 subcarriers) in one slot and may include a number of resource elements. Each resource element may cover one subcarrier in one symbol period (for example, in time) and may be used to send one modulation symbol, which may be a real or complex value.

An interlace structure may be used for each of the downlink and uplink for FDD in certain telecommunications systems (for example, NR) . For example, Q interlaces with indices of 0 through Q –1 may be defined, where Q may be equal to 4, 6, 8, 10, or some other value. Each interlace may include slots that are spaced apart by Q frames. In particular, interlace q may include slots q, q + Q, q + 2Q, etc., where q ∈ {0, …, Q –1} .

A UE may be located within the coverage of multiple BSs. One of these BSs may be selected to serve the UE. The serving BS may be selected based at least in part on various criteria such as received signal strength, received signal quality, path loss, or the like, or combinations thereof. Received signal quality may be quantified by a signal-to-noise-and-interference ratio (SNIR) , or a reference signal received quality (RSRQ) , or some other metric. The UE may operate in a dominant interference scenario in which the UE may observe high interference from one or more interfering BSs.

While aspects of the examples described herein may be associated with NR or 5G technologies, aspects of the present disclosure may be applicable with other wireless communication systems. New Radio (NR) may refer to radios configured to operate according to a new air interface (for example, other than Orthogonal Frequency Divisional Multiple Access (OFDMA) -based air interfaces) or fixed transport layer (for example, other than Internet Protocol (IP) ) . In aspects, NR may utilize OFDM with a CP (herein referred to as cyclic prefix OFDM or CP-OFDM) or SC-FDM on the uplink, may utilize CP-OFDM on the downlink and include support for half-duplex operation using TDD. In aspects, NR may, for example, utilize OFDM with a CP (herein referred to as CP-OFDM) or discrete Fourier transform spread orthogonal frequency-division multiplexing (DFT-s-OFDM) on the uplink, may utilize CP-OFDM on the downlink and include support for half-duplex operation using TDD. NR may include Enhanced Mobile Broadband (eMBB) service targeting wide bandwidth (for example, 80 megahertz (MHz) and beyond) , millimeter wave (mmW) targeting high carrier frequency (for example, 60 gigahertz (GHz) ) , massive MTC (mMTC) targeting non-backward compatible MTC techniques, or mission critical targeting ultra reliable low latency communications (URLLC) service.

In some aspects, a single component carrier bandwidth of 100 MHz may be supported. NR resource blocks may span 12 sub-carriers with a sub-carrier bandwidth of 60 or 120 kilohertz (kHz) over a 0.1 millisecond (ms) duration. Each radio frame may include 40 slots and may have a length of 10 ms. Consequently, each slot may have a length of 0.25 ms. Each slot may indicate a link direction (for example, DL or UL) for data transmission and the link direction for each slot may be dynamically switched. Each slot may include DL/UL data as well as DL/UL control data.

Beamforming may be supported and beam direction may be dynamically configured. MIMO transmissions with precoding also may be supported. MIMO configurations in the DL may support up to 8 transmit antennas with multi-layer DL transmissions up to 8 streams and up to 2 streams per UE. Multi-layer transmissions with up to 2 streams per UE may be supported. Aggregation of multiple cells may be supported with up to 8 serving cells. Alternatively, NR may support a different air interface, other than an OFDM-based interface. NR networks may include entities such as central units or distributed units.

Figure 5 is a diagram conceptually illustrating an example 500 of a DL-centric slot or wireless communication structure. The DL-centric slot may include a control portion 502. The control portion 502 may exist in the initial or beginning portion of the DL-centric slot. The control portion 502 may include various scheduling information or control information corresponding to various portions of the DL-centric slot. In some configurations, the control portion 502 may be a physical DL control channel (PDCCH) , as indicated in Figure 5. In some aspects, the control portion 502 may include legacy PDCCH information, shortened PDCCH (sPDCCH) information) , a control format indicator (CFI) value (for example, carried on a physical control format indicator channel (PCFICH) ) , one or more grants (for example, downlink grants, uplink grants, etc. ) , or the like.

The DL-centric slot also may include a DL data portion 504. The DL data portion 504 may sometimes be referred to as the payload of the DL-centric slot. The DL data portion 504 may include the communication resources utilized to communicate DL data from the scheduling entity (for example, UE or BS) to the subordinate entity (for example, UE) . In some configurations, the DL data portion 504 may be a physical DL shared channel (PDSCH) .

The DL-centric slot also may include an UL short burst portion 506. The UL short burst portion 506 may sometimes be referred to as an UL burst, an UL burst portion, a common UL burst, a short burst, an UL short burst, a common UL short burst, a common UL short burst portion, or various other suitable terms. In some aspects, the UL short burst portion 506 may include one or more reference signals. Additionally, or alternatively, the UL short burst portion 506 may include feedback information corresponding to various other portions of the DL-centric slot. For example, the UL short burst portion 506 may include feedback information corresponding to the control portion 502 or the data portion 504. Non-limiting examples of information that may be included in the UL short burst portion 506 include an ACK signal (for example, a PUCCH ACK, a PUSCH ACK, an immediate ACK) , a NACK signal (for example, a PUCCH NACK, a PUSCH NACK, an immediate NACK) , a scheduling request (SR) , a buffer status report (BSR) , a HARQ indicator, a channel state indication (CSI) , a channel quality indicator (CQI) , a sounding reference signal (SRS) , a demodulation reference signal (DMRS) , PUSCH data, or various other suitable types of information. The UL short burst portion 506 may include additional or alternative information, such as information pertaining to random access channel (RACH) procedures, scheduling requests, and various other suitable types of information.

As illustrated in Figure 5, the end of the DL data portion 504 may be separated in time from the beginning of the UL short burst portion 506. This time separation may sometimes be referred to as a gap, a guard period, a guard interval, or various other suitable terms. This separation provides time for the switch-over from DL communication (for example, reception operation by the subordinate entity (for example, UE) ) to UL communication (for example, transmission by the subordinate entity (for example, UE) ) . The foregoing is merely one example of a DL-centric wireless communication structure, and alternative structures having similar features may be used without necessarily deviating from the aspects described herein.

Figure 6 is a diagram conceptually illustrating an example 600 of a UL-centric slot or wireless communication structure. The UL-centric slot may include a control portion 602. The control portion 602 may exist in the initial or beginning portion of the UL-centric slot. The control portion 602 in Figure 6 may be similar to the control portion 502 described above with reference to Figure 5. The UL-centric slot also may include an UL long burst portion 604. The UL long burst portion 604 may sometimes be referred to as the payload of the UL-centric slot. The UL portion may refer to the communication resources utilized to communicate UL data from the subordinate entity (for example, UE) to the scheduling entity (for example, UE or BS) . In some configurations, the control portion 602 may be a physical DL control channel (PDCCH) .

As illustrated in Figure 6, the end of the control portion 602 may be separated in time from the beginning of the UL long burst portion 604. This time separation may sometimes be referred to as a gap, guard period, guard interval, or various other suitable terms. This separation provides time for the switch-over from DL communication (for example, reception operation by the scheduling entity) to UL communication (for example, transmission by the scheduling entity) .

The UL-centric slot also may include an UL short burst portion 606. The UL short burst portion 606 in Figure 6 may be similar to the UL short burst portion 506 described above with reference to Figure 5, and may include any of the information described above in connection with Figure 5. The foregoing is merely one example of an UL-centric wireless communication structure, and alternative structures having similar features may be used without necessarily deviating from the aspects described herein.

In some circumstances, two or more subordinate entities (for example, UEs) may communicate with each other using sidelink signals. Real-world applications of such sidelink communications may include public safety, proximity services, UE-to-network relaying, vehicle-to-vehicle (V2V) communications, Internet of Everything (IoE) communications, IoT communications, mission-critical mesh, or various other suitable applications. Generally, a sidelink signal may refer to a signal communicated from one subordinate entity (for example, UE1) to another subordinate entity (for example, UE2) without relaying that communication through the scheduling entity (for example, UE or BS) , even though the scheduling entity may be utilized for scheduling or control purposes. In some aspects, the sidelink signals may be communicated using a licensed spectrum (unlike wireless local area networks, which typically use an unlicensed spectrum) .

In one example, a wireless communication structure, such as a frame, may include both UL-centric slots and DL-centric slots. In this example, the ratio of UL-centric slots to DL-centric slots in a frame may be dynamically adjusted based at least in part on the amount of UL data and the amount of DL data that are transmitted. For example, if there is more UL data, then the ratio of UL-centric slots to DL-centric slots may be increased. Conversely, if there is more DL data, then the ratio of UL-centric slots to DL-centric slots may be decreased.

Figures 7A–7E are diagrams illustrating examples 700 of semi-static slot configuration for time division multiplexed uplink carriers. As shown in Figure 7A, a UE (such as a UE 120) may be in communication with a base station (such as a base station 110) . In the example shown in Figure 7A, the base station may be associated with a cell in which multiple uplink carriers are configured and time division multiplexed with one another, whereby the UE can perform transmission via one uplink carrier at a time (such as within a particular symbol or slot) . In some aspects, the multiple uplink carriers may be configured in a supplemental uplink (SUL) mode or a time division multiplexing carrier aggregation mode. In some aspects, the multiple uplink carriers may include a first uplink carrier operating in a time division duplexing (TDD) mode (such as in the 3.5 GHz frequency band) and a second uplink carrier operating in frequency division duplexing (FDD) mode (such as in the 2.1 GHz frequency band) or an SUL mode. Furthermore, while the example shown in Figure 7A illustrates the UE in communication with a single base station, in some aspects, the multiple uplink carriers may be associated with different base stations, different TRPs associated with a single base station, or the like.

As shown in Figure 7A, and by reference number 710, the base station may transmit, and the UE may receive, cell-specific signaling to configure one or more slot patterns for the multiple uplink carriers that are time division multiplexed with one another. For example, in some aspects, the cell-specific signaling may include higher-layer signaling, such as a radio resource control (RRC) message, to indicate a default slot pattern for a primary uplink carrier, as described in further detail below with reference to Figure 7B. Additionally, or alternatively, the cell-specific signaling may include higher-layer signaling, such as an RRC message, to indicate multiple candidate slot patterns, and each of the multiple candidate slot patterns may include a joint slot configuration to be applied to the multiple uplink carriers, as described in further detail below with reference to Figure 7C. In some aspects, the cell-specific signaling may be applicable to each UE that is located in the cell associated with the base station.

As further shown in Figure 7A, and by reference number 712, the base station may transmit, and the UE may receive, UE-specific signaling to assign uplink slots among the first uplink carrier and the second uplink carrier. For example, in some aspects, the UE-specific signaling may include an RRC message, a media access control (MAC) control element (MAC-CE) , or downlink control information (DCI) . In some aspects, where the cell-specific signaling indicates a default slot pattern for the primary uplink carrier, the UE-specific signaling may indicate one or more modifications to the default slot pattern (such as switching all uplink slots in the primary uplink carrier to instead be assigned to the corresponding slots on the secondary uplink carrier) . Additionally, or alternatively, where the cell-specific signaling includes multiple candidate slot patterns to indicate joint slot configurations for the primary and second uplink carriers, the UE-specific signaling may indicate one of the multiple candidate slot patterns to be activated.

In some aspects, the UE-specific signaling to assign the uplink slots among the first uplink carrier and the second uplink carrier may be based on a location of the UE within a cell associated with the base station. For example, the default slot pattern may be defined to improve performance for UEs located at or near the center of the cell associated with the base station, such as by assigning uplink slots to the primary uplink carrier that operates at a relatively higher frequency to enable uplink transmission at a higher data rate, and the UE-specific signaling may be provided to modify the default slot pattern to improve performance for UEs located near the edge of the cell, such as by reassigning one or more uplink slots to the secondary uplink carrier that operates at a relatively lower frequency to improve coverage at the cell edge. Additionally, or alternatively, the multiple candidate slot patterns may be defined for various locations within the cell, and the UE-specific signaling may indicate the particular candidate slot pattern to be activated based on the location of the UE in the cell. Accordingly, in some aspects, the UE may provide a measurement report to the base station (such as on a periodic basis, based on a triggering event, or the like) , and the measurement report may include an RSRP value, an RSSI value, an RSRQ value, a CQI, or the like, which may enable the base station to estimate a location of the UE within the cell and determine the appropriate slot configuration for the UE based on the estimated location of the UE.

In some aspects, as shown in Figure 7B, the base station may configure a default slot pattern to be applied on the primary uplink carrier. For example, in the particular example illustrated in Figure 7B, the default slot pattern is a cell-specific (or cell-wide) configuration that applies to all UEs located in the cell associated with the base station, and which may be applied by the UE when the UE is located at the cell center. However, it will be appreciated that in some aspects, the default slot pattern may be defined for cases in which the UE is located at the cell edge or another suitable location within the cell. Furthermore, as shown in Figure 7B, the primary uplink carrier may correspond to a TDD carrier that serves as an uplink and a downlink carrier, and the secondary uplink carrier may correspond to an SUL carrier or an FDD uplink carrier that is paired with an FDD downlink carrier (the FDD downlink carrier is not illustrated for brevity) . Accordingly, as shown, each slot is the secondary uplink carrier is an uplink slot, and each slot in the primary uplink carrier is either an uplink slot, a downlink slot, or a special (or switching) slot to enable the UE to switch from a downlink to an uplink. A person having ordinary skill in the art will readily appreciate that the configuration of the multiple uplink carriers may vary in other cases, and the particular configuration illustrated in Figures 7B–7E are for illustration purposes only. For example, in some aspects, the multiple uplink carriers may include a first TDD carrier on a high-frequency band and a second TDD carrier on a low-frequency band. Furthermore, in some aspects, the primary uplink carrier may correspond to the high-frequency band or the low-frequency band. Furthermore, in cases where the secondary uplink carrier is an SUL carrier, there are two uplink carriers (one SUL carrier and one TDD uplink carrier) and one downlink carrier (the TDD downlink carrier) , whereas there are two uplink carriers and two downlink carriers (one on a high-frequency band and one on a low-frequency band) in time division multiplexing carrier aggregation.

In some aspects, as mentioned above, the base station may generally configure the default slot pattern to be applied on the primary uplink carrier using higher-layer signaling, such as an RRC message. For example, in Figure 7B, the default slot pattern may be indicated as ‘DDDSUDDSUU’ to indicate that the first three slots are downlink slots, the fourth slot is a special slot to switch from the downlink to the uplink, the fifth slot is an uplink slot, the sixth and seventh slots are downlink slots, the eighth slot is another special slot to switch from the downlink to the uplink, and the final two slots are uplink slots. Accordingly, the UE may receive the default slot configuration via the higher-layer signaling, and the UE may use the default slot configuration to determine a slot pattern to be used for the primary uplink carrier and the secondary uplink carrier that are time division multiplexed with one another. For example, because uplink transmission can only be performed on one uplink carrier at a time in a time division multiplexing configuration, the UE may determine that uplink transmissions cannot be performed on the secondary uplink carrier during the fifth, ninth, or tenth slots based on the default slot pattern defining such slots as uplink slots on the primary uplink carrier. However, as mentioned above, in some cases performance for a UE may be improved by assigning uplink slots to the secondary uplink carrier, which may operate at a lower frequency and offer better coverage.

Accordingly, as shown in Figure 7B, and by reference number 720, the UE-specific signaling may be used to switch uplink slots that are assigned to the primary carrier to the secondary uplink carrier (such as based on a measurement report indicating that the UE has moved closer to the cell edge) . In this case, the fifth, ninth, and tenth slots that the default slot pattern indicated to be uplink slots on the primary uplink carrier may be switched to the secondary uplink carrier. Furthermore, in some aspects, the base station may transmit additional UE-specific signaling to the UE to switch the slot pattern back to the default slot pattern (such as based on a measurement report indicating that the UE has moved closer to the cell center) . Additionally, or alternatively, in cases where the base station determines that the UE is in a location that corresponds to a location for which the default slot pattern was configured (such as the cell center) , the base station may not transmit any UE-specific signaling to the UE, in which case the UE may follow the default slot pattern.

In some aspects, as shown in Figure 7C, the base station may configure multiple candidate slot patterns, each of which may define a joint slot pattern to be applied on the primary uplink carrier and the secondary uplink carrier. For example, in the particular example illustrated in Figure 7C, the candidate slot patterns include a cell center slot pattern and a cell edge slot pattern that applies to all UEs located in the cell associated with the base station. However, it will be appreciated that in some aspects, the multiple candidate slot patterns may include additional slot patterns for other regions, areas, or other suitable locations within the cell associated with the base station (such as an inner region, an outer region, an area that may have poor coverage on higher frequencies due to the presence of obstacles, or the like) . Furthermore, in the example shown in Figure 7C, the primary uplink carrier may correspond to a TDD carrier that serves as an uplink and a downlink carrier, and the secondary uplink carrier may correspond to an SUL carrier or an FDD uplink carrier that is paired with an FDD downlink carrier. Accordingly, as shown, each slot is the secondary uplink carrier is an uplink slot, and each slot in the primary uplink carrier is either an uplink slot, a downlink slot, or a special (or switching) slot to enable the UE to switch from a downlink to an uplink.

In some aspects, as mentioned above, the base station may configure the multiple candidate slot patterns to jointly indicate an assignment of uplink slots among the primary uplink carrier and the secondary uplink carrier using higher-layer signaling, such as an RRC message. For example, in Figure 7C, the cell center slot pattern may be indicated as ‘DDDSUDDSUU’ to indicate that the first three slots are downlink slots, the fourth slot is a special slot to switch from the downlink to the uplink, the fifth slot is an uplink slot, the sixth and seventh slots are downlink slots, the eighth slot is another special slot to switch from the downlink to the uplink, and the final two slots are uplink slots. Furthermore, in Figure 7C, the cell edge slot pattern may be indicated as ‘DDDSU _lowDDSU _lowU _low’ to indicate that the three uplink slots are assigned to the low-frequency SUL or FDD UL carrier. Accordingly, the UE may receive information indicating or otherwise configuring the multiple candidate slot patterns, and the UE may subsequently receive UE-specific signaling (such as via an RRC message, a MAC-CE, DCI, or the like) to activate a particular one of the multiple candidate slot patterns. Accordingly, as shown in Figure 7C, and by reference number 730, the UE may activate one of the multiple candidate slot patterns indicated in the UE-specific signaling (such as based on a measurement report indicating a location of the UE within the cell) .

In some aspects, as shown in Figure 7D, and by reference number 740, the UE may map an indicator contained in the UE-specific signaling to a corresponding slot configuration. For example, in some aspects, the UE-specific signaling may include a one-bit indicator to indicate whether all uplink slots in a default (or cell center) slot configuration are to be assigned to the high-frequency TDD uplink carrier or to the lower-frequency SUL or FDD UL carrier (such as a ‘0’ to indicate that all uplink slots in the default or cell center slot configuration are to be assigned to the high-frequency TDD uplink carrier, or a ‘1’ to indicate that all uplink slots in the default or cell center slot configuration are to be assigned to the lower-frequency SUL or FDD UL carrier) .

Additionally, or alternatively, a multi-bit indicator may be used to switch among different slot patterns or to activate a particular slot pattern (such as a two-bit indicator to identify a particular slot pattern among up to four different slot patterns, a three-bit indicator to identify a particular slot pattern among up to eight different slot patterns, and so on) . For example, in Figure 7D, the default or cell center pattern may be associated with a ‘00’ indicator, and the cell edge pattern may be associated with a ‘11’ indicator. Furthermore, in Figure 7D, additional slot patterns are configured for an inner region and an outer region of the cell (although such slot patterns may be associated with other suitable regions or characteristics associated with the cell) . In the illustrated example, the inner region pattern assigns uplink slots in the first half of the default or cell center pattern to the high-frequency TDD uplink carrier, assigns uplink slots in the second half of the default or cell center pattern to the lower-frequency SUL or FDD UL carrier, and the inner region pattern may be identified with a ‘01’ indicator. Furthermore, in Figure 7D, the outer region pattern assigns uplink slots in the first half of the default or cell center pattern to the lower-frequency SUL or FDD UL carrier, assigns uplink slots in the second half of the default or cell center pattern to the high-frequency TDD uplink carrier, and the outer region pattern may be identified with a ‘10’ indicator.

Additionally, or alternatively, in some aspects, the UE-specific signaling may include a bitmap of size N to indicate an assignment of uplink slots among the primary uplink carrier and the secondary uplink carrier, where N is a quantity of uplink slots in the default or cell center slot configuration. For example, in some aspects, each bit (b _i) in the bitmap may include a value of ‘0’ or ‘1’ , where a value of ‘0’ indicates that the i-th bit in the default or cell center configuration is on the higher-frequency uplink carrier (such as to enable transmission at a high data rate) and a value of ‘1’ indicates that the i-th bit in the default or cell center configuration is on the lower-frequency uplink carrier (such as to enable improved coverage) . For example, in Figure 7D, the default or cell center pattern may be associated with a bitmap of ‘000’ to indicate that all three uplink slots in the default or cell center pattern are assigned to the higher-frequency band. Furthermore, the inner region pattern may be associated with a bitmap of ‘011’ to indicate that the first uplink slot in the default or cell center pattern is assigned to the higher-frequency band and the second and third uplink slots in the default or cell center pattern are assigned to the lower-frequency band. Furthermore, as shown in Figure 7D, the outer region pattern may be associated with a bitmap of ‘100’ to indicate that the first uplink slot in the default or cell center pattern is assigned to the lower-frequency band and the second and third uplink slots in the default or cell center pattern are assigned to the higher-frequency band, and the cell edge pattern may be associated with a bitmap of ‘111’ to indicate that all three uplink slots in the default or cell center pattern are assigned to the lower-frequency band.

Accordingly, the base station may configure various possible slot patterns that can be used in the cell (such as in different regions of the cell) , and may include a sequence of bits in the UE-specific signaling to indicate the particular slot pattern that the UE is to apply on the primary uplink carrier and the secondary uplink carrier.

In some aspects, as mentioned elsewhere herein, the UE can only perform an uplink transmission on one uplink carrier in a given symbol or slot in cases where multiple uplink carriers are time division multiplexed with one another. However, in some cases, different carriers may be associated with different subcarrier spacings, numerologies, or the like, whereby a duration of a slot may vary from one carrier to another. Accordingly, in some aspects, different techniques can be used to define a correspondence among slots in different uplink carriers, which may affect whether there are any restrictions on the UE transmitting on the uplink at a given time.

For example, as shown in Figure 7E, and by reference number 750, simultaneous uplink transmission may be restricted at a slot level, where a slot in the secondary uplink carrier (such as a low-frequency SUL or FDD UL carrier) cannot be used for uplink communication if the corresponding slot in the primary uplink carrier (such as a high-frequency TDD carrier) is an uplink slot. In some aspects, the primary uplink carrier and the secondary uplink carrier may have different numerologies, which generally corresponds to a subcarrier spacing. For example, a single slot on a carrier with a subcarrier spacing of 15 kHz may correspond to two slots on another carrier with a subcarrier spacing of 30 kHz. For example, in Figures 7B–7E, the primary uplink carrier in the high-frequency band may have a subcarrier spacing of 30 kHz and the secondary uplink carrier may have a subcarrier spacing of 15 kHz, whereby one slot on the high-frequency band corresponds to half of a slot on the low-frequency band. Accordingly, when simultaneous uplink transmission is restricted at the slot level, uplink transmission may be restricted during the entire slot in the secondary uplink carrier even the restricted slot only overlaps with the uplink slot in the primary uplink carrier for half of the slot. In this case, a subcarrier spacing in the primary uplink carrier may be defined as

kHz, and the subcarrier spacing in the secondary uplink carrier may be defined as

kHz. Accordingly, in some aspects, a slot n in a first uplink carrier may generally correspond to slot

and to slot

in a second uplink carrier, whereby one slot on the first uplink carrier may correspond to two slots on the second uplink carrier if the first uplink carrier has a lower subcarrier spacing than the second uplink carrier.

Additionally, or alternatively, as shown in Figure 7E, and by reference number 752, simultaneous uplink transmission may be restricted at a symbol level, where transmission on the secondary uplink carrier may be restricted during only one or more symbols that correspond to an uplink slot on the primary uplink carrier. Accordingly, when simultaneous uplink transmission is restricted at the symbol level, the second half of the slot on the low-frequency band can be used for uplink transmission. In this way, efficiency or resource utilization is improved (such as enabling faster ACK/NACK uplink transmissions) , because the UE can transmit during a greater proportion of the available symbols in a given time period.

Figure 8 is a diagram illustrating an example process 800 performed, for example, by a UE, in accordance with various aspects of the present disclosure. Example process 800 is an example where a UE, such as the UE 120, performs operations associated with semi-static slot configuration for time division multiplexed uplink carriers.

As shown in Figure 8, in some aspects, the process 800 may include receiving, from a base station, information configuring a slot pattern to be used for a first uplink carrier and a second uplink carrier that are time division multiplexed with one another, the slot pattern including a first set of uplink slots on the first uplink carrier and a second set of uplink slots on the second uplink carrier (block 810) . For example, the UE (such as using antenna 252, DEMOD 254, MIMO detector 256, receive processor 258, controller/processor 280) may receive, from a base station, information configuring a slot pattern to be used for a first uplink carrier and a second uplink carrier that are time division multiplexed with one another, as described above. In some aspects, the slot pattern includes a first set of uplink slots on the first uplink carrier and a second set of uplink slots on the second uplink carrier.

As shown in Figure 8, in some aspects, the process 800 may include transmitting information to the base station on an uplink based at least in part on the slot pattern to be used for the first uplink carrier and the second uplink carrier (block 820) . For example, the UE (such as using controller/processor 280, transmit processor 264, TX MIMO processor 266, MOD 254, antenna 252) may transmit information to the base station on an uplink based at least in part on the slot pattern to be used for the first uplink carrier and the second uplink carrier, as described above.

The process 800 may include additional aspects, such as any single aspect or any combination of aspects described below or in connection with one or more other processes described elsewhere herein.

In a first aspect, receiving the information configuring the slot pattern for the first uplink carrier and the second uplink carrier includes receiving first signaling to indicate a default slot pattern including one or more slots that are scheduled for uplink communication on the first uplink carrier, and receiving second signaling to modify the default slot pattern to switch the one or more slots from being scheduled for uplink communication on the first uplink carrier to uplink communication on the second uplink carrier, where the slot pattern corresponds to the modified default slot pattern.

In a second aspect, alone or in combination with the first aspect, receiving the information configuring the slot pattern for the first uplink carrier and the second uplink carrier includes receiving signaling to indicate a default slot pattern including one or more slots that are scheduled for uplink communication on the first uplink carrier, and the slot pattern corresponds to the default slot pattern.

In a third aspect, alone or in combination with one or more of the first and second aspects, receiving the information configuring the slot pattern for the first uplink carrier and the second uplink carrier includes receiving first signaling to indicate multiple candidate slot patterns, each candidate slot pattern including a joint slot configuration for the first uplink carrier and the second uplink carrier, and receiving second signaling to activate one of the multiple candidate slot patterns as the slot pattern to be used for the first uplink carrier and the second uplink carrier.

In a fourth aspect, alone or in combination with one or more of the first through third aspects, the information configuring the slot pattern includes first signaling to indicate one or more cell-specific slot patterns for each UE in a cell associated with the base station, and second signaling that indicates the slot pattern that the particular UE is to use for the first uplink carrier and the second uplink carrier based at least in part on the one or more cell-specific slot patterns.

In a fifth aspect, alone or in combination with one or more of the first through fourth aspects, the first signaling includes a first RRC message and the second signaling includes one or more of a second RRC message, a MAC-CE, or DCI.

In a sixth aspect, alone or in combination with one or more of the first through fifth aspects, the process 800 includes transmitting a measurement report to the base station, with the slot pattern to be used for the first uplink carrier and the second uplink carrier based at least in part on the measurement report.

In a seventh aspect, alone or in combination with one or more of the first through sixth aspects, the information configuring the slot pattern includes one or more bits to indicate an assignment of the first set of uplink slots and the second set of uplink slots among the first uplink carrier and the second uplink carrier.

In an eighth aspect, alone or in combination with one or more of the first through seventh aspects, communication on the uplink is restricted on the second uplink carrier during one or more slots or symbols that correspond to the first set of uplink slots on the first uplink carrier.

Although Figure 8 shows example blocks of the process 800, in some aspects, the process 800 may include additional blocks, fewer blocks, different blocks, or differently arranged blocks than those depicted in Figure 8. Additionally, or alternatively, two or more of the blocks of the process 800 may be performed in parallel.

Figure 9 is a diagram illustrating an example process 900 performed, for example, by a base station, in accordance with various aspects of the present disclosure. Example process 900 is an example where a base station, such as the base station 110, performs operations associated with semi-static slot configuration for time division multiplexed uplink carriers.

As shown in Figure 9, in some aspects, the process 900 may include transmitting, to a UE, information configuring a slot pattern to be used for a first uplink carrier and a second uplink carrier that are time division multiplexed with one another, the slot pattern including a first set of uplink slots on the first uplink carrier and a second set of uplink slots on the second uplink carrier (block 910) . For example, the base station (such as using controller/processor 240, transmit processor 220, TX MIMO processor 230, MOD 232, antenna 234) may transmit, to a UE, information configuring a slot pattern to be used for a first uplink carrier and a second uplink carrier that are time division multiplexed with one another, as described above. In some aspects, the slot pattern includes a first set of uplink slots on the first uplink carrier and a second set of uplink slots on the second uplink carrier.

As shown in Figure 9, in some aspects, the process 900 may include receiving information transmitted by the UE on an uplink based at least in part on the slot pattern to be used for the first uplink carrier and the second uplink carrier (block 920) . For example, the base station (such as using antenna 234, DEMOD 232, MIMO detector 236, receive processor 238, controller/processor 240) may receive information transmitted by the UE on an uplink based at least in part on the slot pattern to be used for the first uplink carrier and the second uplink carrier, as described above.

The process 900 may include additional aspects, such as any single aspect or any combination of aspects described below or in connection with one or more other processes described elsewhere herein.

In a first aspect, transmitting the information configuring the slot pattern for the first uplink carrier and the second uplink carrier includes transmitting first signaling to indicate a default slot pattern including one or more slots that are scheduled for uplink communication on the first uplink carrier and transmitting second signaling to modify the default slot pattern to switch the one or more slots from being scheduled for uplink communication on the first uplink carrier to uplink communication on the second uplink carrier, with the slot pattern corresponding to the modified default slot pattern.

In a second aspect, alone or in combination with the first aspect, transmitting the information configuring the slot pattern for the first uplink carrier and the second uplink carrier includes transmitting signaling to indicate a default slot pattern including one or more slots that are scheduled for uplink communication on the first uplink carrier, with the slot pattern corresponding to the default slot pattern.

In a third aspect, alone or in combination with one or more of the first and second aspects, transmitting the information configuring the slot pattern for the first uplink carrier and the second uplink carrier includes transmitting first signaling to indicate multiple candidate slot patterns, each candidate slot pattern including a joint slot configuration for the first uplink carrier and the second uplink carrier, and transmitting second signaling to activate one of the multiple candidate slot patterns as the slot pattern to be used for the first uplink carrier and the second uplink carrier.

In a sixth aspect, alone or in combination with one or more of the first through fifth aspects, the process 900 includes receiving a measurement report from the UE and determining the slot pattern to be used for the first uplink carrier and the second uplink carrier based at least in part on the measurement report.

Although Figure 9 shows example blocks of the process 900, in some aspects, the process 900 may include additional blocks, fewer blocks, different blocks, or differently arranged blocks than those depicted in Figure 9. Additionally, or alternatively, two or more of the blocks of the process 900 may be performed in parallel.

The foregoing disclosure provides illustration and description, but is not intended to be exhaustive or to limit the aspects to the precise form disclosed.

Modifications and variations may be made in light of the above disclosure or may be acquired from practice of the aspects.

As used herein, the term “component” is intended to be broadly construed as hardware, firmware, or a combination of hardware and software. As used herein, a processor is implemented in hardware, firmware, or a combination of hardware and software. As used herein, the phrase “based on” is intended to be broadly construed to mean “based at least in part on. ”

Some aspects are described herein in connection with thresholds. As used herein, satisfying a threshold may refer to a value being greater than the threshold, greater than or equal to the threshold, less than the threshold, less than or equal to the threshold, equal to the threshold, not equal to the threshold, or the like.

As used herein, a phrase referring to “at least one of” a list of items refers to any combination of those items, including single members. As an example, “at least one of: a, b, or c” is intended to cover: a, b, c, a-b, a-c, b-c, and a-b-c.

The various illustrative logics, logical blocks, modules, circuits and algorithm processes described in connection with the aspects disclosed herein may be implemented as electronic hardware, computer software, or combinations of both. The interchangeability of hardware and software has been described generally, in terms of functionality, and illustrated in the various illustrative components, blocks, modules, circuits and processes described above. Whether such functionality is implemented in hardware or software depends upon the particular application and design constraints imposed on the overall system.

The hardware and data processing apparatus used to implement the various illustrative logics, logical blocks, modules and circuits described in connection with the aspects disclosed herein may be implemented or performed with a general purpose single-or multi-chip processor, a digital signal processor (DSP) , an application specific integrated circuit (ASIC) , a field programmable gate array (FPGA) or other programmable logic device, discrete gate or transistor logic, discrete hardware components, or any combination thereof designed to perform the functions described herein. A general purpose processor may be a microprocessor, or, any conventional processor, controller, microcontroller, or state machine. A processor also may be implemented as a combination of computing devices, for example, a combination of a DSP and a microprocessor, a plurality of microprocessors, one or more microprocessors in conjunction with a DSP core, or any other such configuration. In some aspects, particular processes and methods may be performed by circuitry that is specific to a given function.

In one or more aspects, the functions described may be implemented in hardware, digital electronic circuitry, computer software, firmware, including the structures disclosed in this specification and their structural equivalents thereof, or in any combination thereof. Aspects of the subject matter described in this specification also can be implemented as one or more computer programs, i.e., one or more modules of computer program instructions, encoded on a computer storage media for execution by, or to control the operation of, data processing apparatus.

If implemented in software, the functions may be stored on or transmitted over as one or more instructions or code on a computer-readable medium. The processes of a method or algorithm disclosed herein may be implemented in a processor-executable software module which may reside on a computer-readable medium. Computer-readable media includes both computer storage media and communication media including any medium that can be enabled to transfer a computer program from one place to another. A storage media may be any available media that may be accessed by a computer. By way of example, and not limitation, such computer-readable media may include RAM, ROM, EEPROM, CD-ROM or other optical disk storage, magnetic disk storage or other magnetic storage devices, or any other medium that may be used to store desired program code in the form of instructions or data structures and that may be accessed by a computer. Also, any connection can be properly termed a computer-readable medium. Disk and disc, as used herein, includes compact disc (CD) , laser disc, optical disc, digital versatile disc (DVD) , floppy disk, and Blu-ray disc where disks usually reproduce data magnetically, while discs reproduce data optically with lasers. Combinations of the above should also be included within the scope of computer-readable media. Additionally, the operations of a method or algorithm may reside as one or any combination or set of codes and instructions on a machine readable medium and computer-readable medium, which may be incorporated into a computer program product.

Various modifications to the aspects described in this disclosure may be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other aspects without departing from the spirit or scope of this disclosure. Thus, the claims are not intended to be limited to the aspects shown herein, but are to be accorded the widest scope consistent with this disclosure, the principles and the novel features disclosed herein.

Additionally, a person having ordinary skill in the art will readily appreciate, the terms “upper” and “lower” are sometimes used for ease of describing the figures, and indicate relative positions corresponding to the orientation of the figure on a properly oriented page, and may not reflect the proper orientation of any device as implemented.

Certain features that are described in this specification in the context of separate aspects also can be implemented in combination in a single aspect. Conversely, various features that are described in the context of a single aspect also can be implemented in multiple aspects separately or in any suitable subcombination. Moreover, although features may be described above as acting in certain combinations and even initially claimed as such, one or more features from a claimed combination can in some cases be excised from the combination, and the claimed combination may be directed to a subcombination or variation of a subcombination.

Similarly, while operations are depicted in the drawings in a particular order, this should not be understood as requiring that such operations be performed in the particular order shown or in sequential order, or that all illustrated operations be performed, to achieve desirable results. Further, the drawings may schematically depict one more example processes in the form of a flow diagram. However, other operations that are not depicted can be incorporated in the example processes that are schematically illustrated. For example, one or more additional operations can be performed before, after, simultaneously, or between any of the illustrated operations. In certain circumstances, multitasking and parallel processing may be advantageous. Moreover, the separation of various system components in the aspects described above should not be understood as requiring such separation in all aspects, and it should be understood that the described program components and systems can generally be integrated together in a single software product or packaged into multiple software products. Additionally, other aspects are within the scope of the following claims. In some cases, the actions recited in the claims can be performed in a different order and still achieve desirable results.

Claims

A method of wireless communication performed by a user equipment (UE) , comprising:

receiving, from a base station, information configuring a slot pattern to be used for a first uplink carrier and a second uplink carrier that are time division multiplexed with one another, the slot pattern comprising a first set of uplink slots on the first uplink carrier and a second set of uplink slots on the second uplink carrier; and

transmitting information to the base station on an uplink based at least in part on the slot pattern to be used for the first uplink carrier and the second uplink carrier.
The method of claim 1, wherein receiving the information configuring the slot pattern for the first uplink carrier and the second uplink carrier includes:

receiving first signaling to indicate a default slot pattern comprising one or more slots that are scheduled for uplink communication on the first uplink carrier; and

receiving second signaling to modify the default slot pattern to switch the one or more slots from being scheduled for uplink communication on the first uplink carrier to uplink communication on the second uplink carrier, wherein the slot pattern corresponds to the modified default slot pattern.
The method of claim 1, wherein receiving the information configuring the slot pattern for the first uplink carrier and the second uplink carrier includes:

receiving signaling to indicate a default slot pattern comprising one or more slots that are scheduled for uplink communication on the first uplink carrier, wherein the slot pattern corresponds to the default slot pattern.
The method of claim 1, wherein receiving the information configuring the slot pattern for the first uplink carrier and the second uplink carrier includes:

receiving first signaling to indicate multiple candidate slot patterns, each candidate slot pattern comprising a joint slot configuration for the first uplink carrier and the second uplink carrier; and

receiving second signaling to activate one of the multiple candidate slot patterns as the slot pattern to be used for the first uplink carrier and the second uplink carrier.
The method of claim 1, wherein the information configuring the slot pattern includes first signaling to indicate one or more cell-specific slot patterns for each UE in a cell associated with the base station and second signaling that indicates the slot pattern that the particular UE is to use for the first uplink carrier and the second uplink carrier based at least in part on the one or more cell-specific slot patterns.
The method of claim 5, wherein the first signaling includes a first radio resource control (RRC) message and the second signaling includes one or more of a second RRC message, a media access control (MAC) control element (MAC-CE) , or downlink control information.
The method of claim 1, further comprising:

transmitting a measurement report to the base station, wherein the slot pattern to be used for the first uplink carrier and the second uplink carrier is based at least in part on the measurement report.
The method of claim 1, wherein the information configuring the slot pattern includes one or more bits to indicate an assignment of the first set of uplink slots and the second set of uplink slots among the first uplink carrier and the second uplink carrier.
The method of claim 1, wherein communication on the uplink is restricted on the second uplink carrier during one or more slots or symbols that correspond to the first set of uplink slots on the first uplink carrier.
A method of wireless communication performed by a base station, comprising:

transmitting, to a user equipment (UE) , information configuring a slot pattern to be used for a first uplink carrier and a second uplink carrier that are time division multiplexed with one another, the slot pattern comprising a first set of uplink slots on the first uplink carrier and a second set of uplink slots on the second uplink carrier; and

receiving information transmitted by the UE on an uplink based at least in part on the slot pattern to be used for the first uplink carrier and the second uplink carrier.
The method of claim 10, wherein transmitting the information configuring the slot pattern for the first uplink carrier and the second uplink carrier includes:

transmitting first signaling to indicate a default slot pattern comprising one or more slots that are scheduled for uplink communication on the first uplink carrier; and

transmitting second signaling to modify the default slot pattern to switch the one or more slots from being scheduled for uplink communication on the first uplink carrier to uplink communication on the second uplink carrier, wherein the slot pattern corresponds to the modified default slot pattern.
The method of claim 10, wherein transmitting the information configuring the slot pattern for the first uplink carrier and the second uplink carrier includes:

transmitting signaling to indicate a default slot pattern comprising one or more slots that are scheduled for uplink communication on the first uplink carrier, wherein the slot pattern corresponds to the default slot pattern.
The method of claim 10, wherein transmitting the information configuring the slot pattern for the first uplink carrier and the second uplink carrier includes:

transmitting first signaling to indicate multiple candidate slot patterns, each candidate slot pattern comprising a joint slot configuration for the first uplink carrier and the second uplink carrier; and

transmitting second signaling to activate one of the multiple candidate slot patterns as the slot pattern to be used for the first uplink carrier and the second uplink carrier.
The method of claim 10, wherein the information configuring the slot pattern includes first signaling to indicate one or more cell-specific slot patterns for each UE in a cell associated with the base station and second signaling that indicates the slot pattern that the particular UE is to use for the first uplink carrier and the second uplink carrier based at least in part on the one or more cell-specific slot patterns.
The method of claim 14, wherein the first signaling includes a first radio resource control (RRC) message and the second signaling includes one or more of a second RRC message, a media access control (MAC) control element (MAC-CE) , or downlink control information.
The method of claim 10, further comprising:

receiving a measurement report from the UE; and

determining the slot pattern to be used for the first uplink carrier and the second uplink carrier based at least in part on the measurement report.
The method of claim 10, wherein the information configuring the slot pattern includes one or more bits to indicate an assignment of the first set of uplink slots and the second set of uplink slots among the first uplink carrier and the second uplink carrier.
The method of claim 10, wherein communication on the uplink is restricted on the second uplink carrier during one or more slots or symbols that correspond to the first set of uplink slots on the first uplink carrier.
A user equipment (UE) for wireless communication, comprising:

a memory; and

one or more processors operatively coupled to the memory, the memory and the one or more processors configured to:

receive, from a base station, information configuring a slot pattern to be used for a first uplink carrier and a second uplink carrier that are time division multiplexed with one another, the slot pattern comprising a first set of uplink slots on the first uplink carrier and a second set of uplink slots on the second uplink carrier; and

transmit information to the base station on an uplink based at least in part on the slot pattern to be used for the first uplink carrier and the second uplink carrier.
A base station for wireless communication, comprising:

a memory; and

one or more processors operatively coupled to the memory, the memory and the one or more processors configured to:

transmit, to a user equipment (UE) , information configuring a slot pattern to be used for a first uplink carrier and a second uplink carrier that are time division multiplexed with one another, the slot pattern comprising a first set of uplink slots on the first uplink carrier and a second set of uplink slots on the second uplink carrier; and

receive information transmitted by the UE on an uplink based at least in part on the slot pattern to be used for the first uplink carrier and the second uplink carrier.
A non-transitory computer-readable medium storing one or more instructions for wireless communication, the one or more instructions comprising:

one or more instructions that, when executed by one or more processors of a user equipment (UE) , cause the one or more processors to:

receive, from a base station, information configuring a slot pattern to be used for a first uplink carrier and a second uplink carrier that are time division multiplexed with one another, the slot pattern comprising a first set of uplink slots on the first uplink carrier and a second set of uplink slots on the second uplink carrier; and

transmit information to the base station on an uplink based at least in part on the slot pattern to be used for the first uplink carrier and the second uplink carrier.
A non-transitory computer-readable medium storing one or more instructions for wireless communication, the one or more instructions comprising:

one or more instructions that, when executed by one or more processors of a base station, cause the one or more processors to:

transmit, to a user equipment (UE) , information configuring a slot pattern to be used for a first uplink carrier and a second uplink carrier that are time division multiplexed with one another, the slot pattern comprising a first set of uplink slots on the first uplink carrier and a second set of uplink slots on the second uplink carrier; and

receive information transmitted by the UE on an uplink based at least in part on the slot pattern to be used for the first uplink carrier and the second uplink carrier.
An apparatus for wireless communication, comprising:

means for receiving, from a base station, information configuring a slot pattern to be used for a first uplink carrier and a second uplink carrier that are time division multiplexed with one another, the slot pattern comprising a first set of uplink slots on the first uplink carrier and a second set of uplink slots on the second uplink carrier; and

means for transmitting information to the base station on an uplink based at least in part on the slot pattern to be used for the first uplink carrier and the second uplink carrier.
An apparatus for wireless communication, comprising:

means for transmitting, to a user equipment (UE) , information configuring a slot pattern to be used for a first uplink carrier and a second uplink carrier that are time division multiplexed with one another, the slot pattern comprising a first set of uplink slots on the first uplink carrier and a second set of uplink slots on the second uplink carrier; and

means for receiving information transmitted by the UE on an uplink based at least in part on the slot pattern to be used for the first uplink carrier and the second uplink carrier.
A non-transitory computer-readable medium storing one or more instructions for wireless communication, the one or more instructions comprising one or more instructions that, when executed by one or more processors, cause the one or more processors to perform operations according to the method of any one of claims 1-18.
An apparatus for wireless communication, comprising:

a memory; and

one or more processors coupled to the memory, the memory and the one or more processors configured to perform operations according to the method of any one of claims 1-18.
An apparatus for wireless communication, comprising means for performing operations according to the method of any one of claims 1-18.