WO2021208052A1

WO2021208052A1 - Uplink transmit switching across carrier aggregation component carriers

Info

Publication number: WO2021208052A1
Application number: PCT/CN2020/085262
Authority: WO
Inventors: Yiqing Cao; Peter Gaal; Timo Ville VINTOLA
Original assignee: Qualcomm Incorporated
Priority date: 2020-04-17
Filing date: 2020-04-17
Publication date: 2021-10-21

Abstract

Aspects of the disclosure relate to a user equipment (UE) providing a downlink interruption time to complete an uplink transmit switching operation to switch a transmit chain from a component carrier (CC) that utilizes FDD to a CC that utilizes TDD; initiating an uplink switching operation for an upcoming slot; receiving a SLIV value indicative of a start symbol value S for which the base station has scheduled a next downlink; determining, based on the start value, that downlink using the FDD CC is scheduled to be inhibited for a contiguous period of time including a transient time and the downlink interruption time; and uploading data via the second CC using the switched transmit chain and a second transmit chain, wherein uploading via the first component carrier is inhibited during the second period of time. Other aspects, embodiments, and features are also claimed and described.

Description

UPLINK TRANSMIT SWITCHING ACROSS CARRIER AGGREGATION COMPONENT CARRIERS

TECHNICAL FIELD

The technology described below relates generally to wireless communication systems, and more particularly, to switching an uplink transmit chain to facilitate more efficient use of available bandwidth. Embodiments can provide and enable techniques for uplink transmit switching across carrier aggregation component carriers.

INTRODUCTION

As the demand for mobile broadband access continues to increase, research and development continue to advance wireless communication technologies not only to meet the growing demand for mobile broadband access, but to advance and enhance the user experience with mobile communications. However, such advances in wireless technology often require costly new hardware and/or can be difficult to incorporate into a conventional form factor.

BRIEF SUMMARY OF SOME EXAMPLES

The following presents a simplified summary of one or more aspects of the present disclosure, in order to provide a basic understanding of such aspects. This summary is not an extensive overview of all contemplated features of the disclosure, and is intended neither to identify key or critical elements of all aspects of the disclosure nor to delineate the scope of any or all aspects of the disclosure. Its sole purpose is to present some concepts of one or more aspects of the disclosure in a simplified form as a prelude to the more detailed description that is presented later.

Aspects of the disclosure relate to a user equipment (UE) providing a downlink interruption time needed to complete an uplink transmit switching operation to switch a transmit train from a component carrier (CC) that utilizes FDD to a CC that utilizes TDD; initiating an uplink switching operation for an upcoming slot; receiving a SLIV value indicative of a start symbol value S for which the base station has scheduled a next downlink; determining, based on the start value, that downlink using the FDD CC is scheduled to be inhibited for a contiguous period of time including a transient time and the downlink interruption time; and uploading data via the second CC using the switched transmit chain and a second transmit chain, wherein uploading via the first component carrier is inhibited during the second period of time. Other aspects, embodiments, and features are also claimed and described.

These and other aspects of the invention will become more fully understood upon a review of the detailed description, which follows. Other aspects, features, and embodiments will become apparent to those of ordinary skill in the art, upon reviewing the following description of specific, exemplary embodiments in conjunction with the accompanying figures. While features may be discussed relative to certain embodiments and figures below, all embodiments can include one or more of the advantageous features discussed herein. In other words, while one or more embodiments may be discussed as having certain advantageous features, one or more of such features may also be used in accordance with the various embodiments discussed herein. In similar fashion, while exemplary embodiments may be discussed below as device, system, or method embodiments it should be understood that such exemplary embodiments can be implemented in various devices, systems, and methods.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic illustration of a wireless communication system in accordance with some aspects of the disclosed subject matter.

FIG. 2 is a conceptual illustration of an example of a radio access network in accordance with some aspects of the disclosed subject matter.

FIG. 3 is a block diagram illustrating a wireless communication system supporting multiple-input multiple-output (MIMO) communication in accordance with some aspects of the disclosed subject matter.

FIG. 4 is a schematic illustration of an organization of wireless resources in an air interface utilizing orthogonal frequency divisional multiplexing (OFDM) in accordance with some aspects of the disclosed subject matter.

FIG. 5 is a schematic illustration of exemplary self-contained slots in accordance with some aspects of the disclosed subject matter.

FIG. 6 is a schematic illustration of timing in a process for uplink transmit switching across carrier aggregation component carriers in accordance with some aspects of the disclosed subject matter.

FIG. 7 is another schematic illustration of timing in a process for uplink transmit switching across carrier aggregation component carriers in accordance with some aspects of the disclosed subject matter.

FIG. 8 is a flow chart illustrating an exemplary process for uplink transmit switching across carrier aggregation component carriers by a user equipment in accordance with some aspects of the disclosed subject matter.

FIG. 9 is a flow chart illustrating an exemplary process for uplink transmit switching across carrier aggregation component carriers by a base station in accordance with some aspects of the disclosed subject matter.

FIG. 10 is a block diagram conceptually illustrating an example of a hardware implementation for a base station in accordance with some aspects of the disclosed subject matter.

FIG. 11 is a block diagram conceptually illustrating an example of a hardware implementation for a user equipment in accordance with some aspects of the disclosed subject matter.

DETAILED DESCRIPTION

The detailed description set forth below in connection with the appended drawings is intended as a description of various configurations and is not intended to represent the only configurations in which the concepts described herein can be practiced. The detailed description includes specific details for the purpose of providing a thorough understanding of various concepts. However, it will be apparent to those skilled in the art that these concepts can be practiced without these specific details. In some instances, well known structures and components are shown in block diagram form in order to avoid obscuring such concepts.

While aspects and embodiments are described in this application by illustration to some examples, those skilled in the art will understand that additional implementations and use cases can come about in many different arrangements and scenarios. Innovations described herein can be implemented across many differing platform types, devices, systems, shapes, sizes, packaging arrangements. For example, embodiments and/or uses can come about via integrated chip embodiments and other non-module-component based devices (e.g., end-user devices, vehicles, communication devices, computing devices, industrial equipment, retail/purchasing devices, medical devices, artificial intelligence-enabled devices, etc. ) . While some examples may or may not be specifically directed to use cases or applications, a wide assortment of applicability of described innovations can occur. Implementations can range a spectrum from chip-level or modular components to non-modular, non-chip-level implementations and further to aggregate, distributed, or OEM devices or systems incorporating one or more aspects of the described innovations. In some practical settings, devices incorporating described aspects and features can also necessarily include additional components and features for implementation and practice of claimed and described embodiments. For example, transmission and reception of wireless signals necessarily includes a number of components for analog and digital purposes (e.g., hardware components including antenna, RF-chains, power amplifiers, modulators, buffer, processor (s) , interleaver, adders/summers, etc. ) . It is intended that innovations described herein can be practiced in a wide variety of devices, chip-level components, systems, distributed arrangements, end-user devices, etc. of varying sizes, shapes and constitution.

Various concepts presented throughout this disclosure can be implemented across a broad variety of telecommunication systems, network architectures, and communication standards.

FIG. 1 is a schematic illustration of a wireless communication system 100 in accordance with some aspects of the disclosed subject matter, and is described as an illustrative example without limitation. In some aspects, wireless communication system 100 can include three interacting domains: a core network 102, a radio access network (RAN) 104, and a user equipment (UE) 106. In some aspects, by virtue of wireless communication system 100, UE 106 can be enabled to carry out data communication with an external data network 110, such as (but not limited to) the Internet.

In some aspects, RAN 104 can implement any suitable wireless communication technology or combination of technologies to provide radio access to UE 106. For example, RAN 104 can operate according to 3 ^rd Generation Partnership Project (3GPP) New Radio (NR) specifications, which is sometimes referred to as 5G NR or simply 5G. As another example, RAN 104 can operate under a hybrid of 5G NR and Evolved Universal Terrestrial Radio Access Network (eUTRAN) standards, which is sometimes referred to as LTE. The 3GPP refers to this hybrid RAN as a next-generation RAN, or NG-RAN. Of course, many other examples can be utilized in connection with the subject matter disclosed herein without departing from the scope of the present disclosure.

As illustrated in the example of FIG. 1, RAN 104 includes various base stations 108. Broadly, a base station can be used to implement a network element in a radio access network responsible for radio transmission and reception in one or more cells to or from a UE, such as UE 106. In different technologies, standards, and/or contexts, various terminology has been used to refer to a network elements that act as a base station. For example, a base station can also be referred to by those skilled in the art using various terminology to refer to a network element that connects one or more UE apparatuses to one or more portions of core network 102, such as a base transceiver station (BTS) , a radio base station, a radio transceiver, a transceiver function, a basic service set (BSS) , an extended service set (ESS) , an access point (AP) , a Node B (NB) , an eNode B (eNB) , a gNode B (gNB) , or some other suitable terminology.

In some aspects, as illustrated in FIG. 1, RAN 104 can support wireless communication for multiple mobile apparatuses. A mobile apparatus can be referred to as user equipment (UE) in 3GPP standards, but can also be referred to by those skilled in the art using various terminology to refer to a network element that provides a user with access to one or more network services, such as a mobile station (MS) , a subscriber station, a mobile unit, a subscriber unit, a wireless unit, a remote unit, a mobile device, a wireless device, a wireless communications device, a remote device, a mobile subscriber station, an access terminal (AT) , a mobile terminal, a wireless terminal, a remote terminal, a handset, a terminal, a user agent, a mobile client, a client, or some other suitable terminology. In general, a UE can be an apparatus (e.g., a mobile apparatus) that provides a user with access to network services.

Within the present document, a "mobile" apparatus need not necessarily have a capability to move, and may be stationary. The term mobile apparatus or mobile device broadly refers to a diverse array of devices and technologies. UEs can include a number of hardware structural components sized, shaped, and arranged to facilitate communication; such components can include antennas, antenna arrays, RF chains, amplifiers, one or more processors, etc., electrically coupled to each other. For example, some non-limiting examples of a mobile apparatus include a mobile, a cellular (cell) phone, a smartphone, a session initiation protocol (SIP) phone, a laptop, a personal computer (PC) , a notebook, a netbook, a smartbook, a tablet, a personal digital assistant (PDA) , and a broad array of embedded systems, e.g., corresponding to an "Internet of things" (IoT) . A mobile apparatus can additionally be an automotive or other transportation vehicle, a remote sensor or actuator, a robot or robotics device, a satellite radio, a global positioning system (GPS) device, an object tracking device, a drone, a multi-copter, a quad-copter, a remote control device, a consumer and/or wearable device, such as eyewear, a wearable camera, a virtual reality device, a smart watch, a health and/or fitness tracker, a digital audio player (e.g., MP3 player) , a camera, a game console, etc. A mobile apparatus can additionally be a digital home device or smart home device such as a home audio device, a home video device, and/or a home multimedia device, an appliance, a vending machine, intelligent lighting, a home security system, a smart meter, etc. A mobile apparatus can additionally be a smart energy device, a security device, a solar panel and/or solar array, a municipal infrastructure device controlling electric power (e.g., a smart grid) , a municipal infrastructure device controlling lighting, a municipal infrastructure device controlling water, etc.; an industrial automation and enterprise device; a logistics controller; agricultural equipment; military defense equipment, vehicles, aircraft, ships, weaponry, etc. Still further, a mobile apparatus can provide for connected medicine or telemedicine support, e.g., health care at a distance. Telehealth devices can include telehealth monitoring devices and telehealth administration devices, whose communication may be given preferential treatment or prioritized access over other types of information (e.g., in terms of prioritized access for transport of critical service data, and/or relevant QoS for transport of critical service data) .

In some aspects, wireless communication between RAN 104 and UE 106 illustrated in FIG. 1 can be described as utilizing an air interface. Transmissions over the air interface from a base station (e.g., base station 108) to one or more UEs (e.g., UE 106) can be referred to as downlink (DL) transmission. In accordance with some aspects of the disclosed subject matter, the term downlink can refer to a point-to-multipoint transmission originating at a scheduling entity (e.g., base station 108) . For example, a downlink can be implemented using one or more broadcast channel multiplexing techniques. In some aspects, transmissions from a UE (e.g., UE 106) to a base station (e.g., base station 108) can be referred to as uplink (UL) transmissions. In accordance with some aspects of the disclosed subject matter, the term uplink can refer to a point-to-point transmission originating at a scheduled entity (e.g., UE 106) .

In some aspects, access to the air interface can be scheduled, wherein a scheduling entity (e.g., a base station of RAN 104, such as base station 108) allocates resources for communication among some or all devices and equipment within its service area or cell. For example, as described below in connection with FIGS. 9 and 10, the scheduling entity can be responsible for scheduling, assigning, reconfiguring, and releasing resources for one or more scheduled entities. In such an example, for scheduled communication scheduled entities (e.g., UEs 106) can utilize resources allocated by a scheduling entity (e.g., base station 108) .

In some aspects, base stations 108 are not the only entities that can function as scheduling entities. For example, in some aspects, a UE can function as a scheduling entity, scheduling resources for one or more scheduled entities (e.g., one or more other UEs) .

As illustrated in FIG. 1, in some aspects, a scheduling entity (e.g., base station 108) can broadcast downlink traffic 112 to one or more scheduled entities (e.g., UEs 106) . Broadly, in some aspects, a scheduling entity (e.g., base station 108) can act as a node or device responsible for scheduling traffic in a wireless communication network, including downlink traffic 112 and, in some examples, uplink traffic 116 from one or more scheduled entities (e.g., UEs 106) to the scheduling entity (e.g., base station 108) . Additionally, a scheduled entity (e.g., UE 106) can act a node or device that receives downlink control information 114, which can include (but is not limited to) scheduling information (e.g., a grant) , synchronization or timing information, and/or other control information from another entity in the wireless communication network such as the scheduling entity (e.g., base station 108) .

In general, in some aspects, base stations 108 can include a backhaul interface for communication with a backhaul portion 120 of the wireless communication system. In some aspects, backhaul 120 can provide a link between a particular base station and core network 102. Further, in some examples, a backhaul network (e.g., including backhaul 120) can provide interconnection between various base stations 108. Various types of backhaul interfaces can be employed, such as a direct physical connection, a virtual network, and/or any other suitable connection, using any suitable transport network.

In some aspects, core network 102 can be a part of the wireless communication system 100, and can be independent of the radio access technology used in RAN 104. In some aspects, core network 102 can be configured according to 5G standards (e.g., 5GC) . Additionally or alternatively, in some aspects, core network 102 can be configured according to a 4G evolved packet core (EPC) , or any other suitable standard or configuration.

In some aspects, for example, as described below in connection with FIGS. 6 to 9, UE 106 can simultaneously connect to multiple base stations 108 and/or can connect to a single base station 108 using multiple component carriers (e.g., at different frequencies) to increase the bandwidth available for communications to and/or from UE 106.

FIG. 2 is a conceptual illustration of an example of a radio access network 200 in accordance with some aspects of the disclosed subject matter, and is described as an illustrative example without limitation. In some aspects, RAN 200 can be an implementation of RAN 104 described above in connection with, and illustrated in, FIG. 1. In some aspects, the geographic area covered by RAN 200 can be divided into cellular regions (cells) that can be uniquely identified by a user equipment (UE) based on an identification broadcasted from one access point or base station. FIG. 2 illustrates

macrocells

202, 204, and 206, and a small cell 208, each of which can include one or more sectors (not shown) . For example, a sector can be defined as a sub-area of a cell, and all sectors within one cell can be served by the same base station. A radio link within a sector can be identified by a single logical identification belonging to that sector. In a cell that is divided into sectors, the multiple sectors within a cell can be formed by groups of antennas with each antenna responsible for communication with UEs in a portion of the cell.

In FIG. 2, two base stations 210 and 212 are illustrated in

cells

202 and 204; and a third base station 214 is shown controlling a remote radio head (RRH) 216 in cell 206. That is, a base station can have an integrated antenna or can be connected to an antenna or RRH by feeder cables. In the illustrated example,

cells

202, 204, and 206 can be referred to as macrocells, as

base stations

210, 212, and 214 support cells having a relatively large size. Further, a base station 218 is shown in small cell 208 (which can be referred to, for example, as a microcell, picocell, femtocell, home base station, home Node B, home eNode B, etc. ) which can overlap with one or more macrocells. In the example illustrated in FIG. 2, cell 208 can be referred to as a small cell, as base station 218 supports a cell having a relatively small size. In some aspects, cell sizing can be done according to system design as well as component constraints.

It is to be understood that radio access network 200 can include any number of wireless base stations and cells. Further, a relay node can be deployed to extend the size or coverage area of a given cell. Additionally,

base stations

210, 212, 214, 218 can provide wireless access points to a core network for any number of mobile apparatuses. In some examples,

base stations

210, 212, 214, and/or 218 can be particular implementations of base station 108 described above in connection with, and illustrated in, FIG. 1.

FIG. 2 further includes a quadcopter 220 (which is sometimes referred to as a drone) , which can be configured to function as a base station. That is, in some examples, a cell may not necessarily be stationary, and the geographic area of the cell can move according to the location of a mobile base station such as quadcopter 220.

Within RAN 200, the cells may include UEs that may be in communication with one or more sectors of each cell. Further, each

base station

210, 212, 214, 218, and 220 can be configured to provide an access point to a core network 102 (e.g., as described above in connection with FIG. 1) for all the UEs in the respective cells. For example,

UEs

222 and 224 can be in communication with base station 210;

UEs

226 and 228 can be in communication with base station 212;

UEs

230 and 232 can be in communication with base station 214 by way of RRH 216; UE 234 can be in communication with base station 218; and UE 236 can be in communication with mobile base station 220. In some examples,

UEs

222, 224, 226, 228, 230, 232, 234, 236, 238, 240, and/or 242 can be particular implementations of UE 106 described above in connection with, and illustrated in, FIG. 1.

In some examples, a mobile network node (e.g., quadcopter 220) can be configured to function as a UE. For example, quadcopter 220 can operate within cell 202 by communicating with base station 210.

In some aspects, sidelink signals can be used between UEs without necessarily relying on scheduling or control information from a base station. For example, two or more UEs (e.g., UEs 226 and 228) can communicate with each other using peer to peer (P2P) or sidelink signals without relaying that communication through a base station (e.g., base station 212) . In another example, UE 238 is illustrated communicating with

UEs

240 and 242. In such an example, UE 238 can function as a scheduling entity or a primary sidelink device, and

UEs

240 and 242 can function as scheduled entities or a non-primary (e.g., secondary) sidelink device. In yet another example, a UE can function as a scheduling entity in a device-to-device (D2D) , peer-to-peer (P2P) , vehicle-to-vehicle (V2V) network, and/or in a mesh network. In a mesh network example,

UEs

240 and 242 can optionally communicate directly with one another in addition to communicating with a scheduling entity (e.g., UE 238) . Thus, in a wireless communication system with scheduled access to time–frequency resources and having a cellular configuration, a P2P configuration, and/or a mesh configuration, a scheduling entity and one or more scheduled entities may communicate utilizing the scheduled resources.

In some aspects, the ability for a UE to communicate while moving, independent of its location (e.g., within radio access network 200) , can be referred to as mobility. The various physical channels between the UE and the radio access network can generally be set up, maintained, and released under the control of an access and mobility management function (AMF, not illustrated, which can be provided via core network 102, which is described above in connection with FIG. 1) , which can include a security context management function (SCMF) that manages the security context for both the control plane and the user plane functionality, and a security anchor function (SEAF) that performs authentication.

In some aspects, the air interface in radio access network 200 can utilize one or more duplexing algorithms. Duplex can refer to a point-to-point communication link where both endpoints can communicate with one another in both directions. Full duplex means both endpoints can simultaneously communicate with one another. Half duplex means only one endpoint can send information to the other at a time. In a wireless link, a full duplex channel generally relies on physical isolation of a transmitter and receiver, and suitable interference cancellation technologies. Full duplex emulation is frequently implemented for wireless links by utilizing frequency division duplex (FDD) or time division duplex (TDD) . In FDD, transmissions in different directions operate at different carrier frequencies. In TDD, transmissions in different directions on a given channel are separated from one another using time division multiplexing. That is, at some times the channel is dedicated for transmissions in one direction, while at other times the channel is dedicated for transmissions in the other direction, where the direction can change very rapidly, e.g., several times per slot.

In some aspects, for example, as described below in connection with FIGS. 6 to 9, UEs, such as

UEs

222, 224, 226, 228, 230, and 232 can simultaneously connect to multiple base stations and/or can connect to a single base station using multiple component carriers (e.g., at different frequencies) to increase the bandwidth available for communications to and/or from the UE. In some such aspects, the different connections can utilize different types of duplexing. For example, a first component carrier can utilize an FDD scheme, while a second component carrier can utilize a TDD scheme. In some aspects, for example, as described below in connection with FIGS. 6 to 9, one of the component carriers can have a higher bandwidth, and it can be desirable to preferentially utilize that component carrier when demand is high for UL or DL bandwidth.

In some aspects of the disclosed subject matter, the scheduling entity and/or scheduled entity can be configured to implement beamforming and/or multiple-input multiple-output (MIMO) technology. FIG. 3 is a block diagram illustrating a wireless communication system 300 supporting multiple-input multiple-output (MIMO) communication in accordance with some aspects of the disclosed subject matter, and is described as an illustrative example without limitation. In a MIMO system, a transmitter 302 can include multiple transmit antennas 304 (e.g., N transmit antennas) and a receiver 306 can include multiple receive antennas 308 (e.g., M receive antennas) . Thus, there are N × M signal paths 310 (e.g., corresponding to a DL transmission to receiver 306) from transmit antennas 304 to receive antennas 308. Each of transmitter 302 and receiver 306 can be implemented, for example, within a scheduling entity (e.g., base station 108) , a scheduled entity (e.g., UE 106) , or any other suitable wireless communication device. Additionally, in some aspects, each of transmitter 302 and receiver 306 can be implemented to operate as both a transmitter and a receiver. For example, receive antennas 308 (and/or corresponding transmit antennas of receiver 306) can be used to transmit signals, and transmit antennas 304 (and/or corresponding receive antennas of transmitter 302) can be used to receive signals. Thus, in such an example, there can be M × N corresponding signal paths (e.g., corresponding to a UL transmission to transmitter 308) .

The use of such multiple antenna technology enables the wireless communication system to exploit the spatial domain to support spatial multiplexing, beamforming, and transmit diversity. Spatial multiplexing can be used to transmit different streams of data, also referred to as layers, simultaneously on the same time-frequency resource. For example, in some aspects, the data streams can be transmitted to a single UE to increase the data rate at which communications can be sent to and/or from the single UE or to multiple UEs to increase the overall system capacity, the latter can be referred to as multi-user MIMO (MU-MIMO) . In a more particular example, MU-MIMO can be achieved by spatially precoding each data stream (i.e., multiplying the data streams with different weighting and phase shifting) and then transmitting each spatially precoded stream through multiple transmit antennas on the downlink. The spatially precoded data streams arrive at the UE (s) with different spatial signatures, which can enable each of the UE (s) to recover the one or more data streams destined for that UE. On the uplink, each UE transmits a spatially precoded data stream, which can enable the base station to identify the source of each spatially precoded data stream.

The number of data streams or layers corresponds to the rank of the transmission. In general, the rank of MIMO system 300 is limited by the number of transmit antennas 304 or receive antennas 308, whichever is lower. In addition, the channel conditions at the UE, as well as other considerations, such as the available resources at the base station, can also affect the transmission rank. For example, the rank (and therefore, the number of data streams) assigned to a particular UE on the downlink can be determined based on the rank indicator (RI) transmitted from the UE to the base station. The RI can be determined based on the antenna configuration (e.g., the number of transmit and receive antennas) and a measured signal-to-interference-and-noise ratio (SINR) on each of the receive antennas. The RI can indicate, for example, the number of layers that can be supported under the current channel conditions. The base station can use the RI, along with resource information (e.g., the available resources and amount of data to be scheduled for the UE) , to assign a transmission rank to the UE.

In a Time Division Duplex (TDD) scheme, the UL and DL are reciprocal, in that each uses different time slots of the same frequency bandwidth. Therefore, in TDD systems, the base station can assign the rank for DL MIMO transmissions based on UL SINR measurements (e.g., based on a Sounding Reference Signal (SRS) transmitted from the UE or other pilot signal) . Based on the assigned rank, the base station can then transmit the CSI-RS with separate C-RS sequences for each layer to provide for multi-layer channel estimation. From the CSI-RS, the UE can measure channel quality across layers and resource blocks and feed back the CQI and RI values to the base station for use in updating the rank and assigning REs for future downlink transmissions.

In the simplest case, as shown in FIG. 3, a rank-2 spatial multiplexing transmission on a 2x2 MIMO antenna configuration can transmit one data stream from each transmit antenna 304. Each data stream reaches each receive antenna 308 along a different signal path 310. Receiver 306 can then reconstruct the data streams using the received signals from each receive antenna 308.

In some aspects, for example, as described below in connection with FIGS. 6 to 9, UEs (e.g.,

UEs

222, 224, 226, 228, 230, and 232) can simultaneously connect to multiple base stations and/or can connect to a single base station using multiple component carriers (e.g., at different frequencies) utilizing different types of duplexing, such as a first component carrier that utilizes an FDD scheme, and a second component carrier that utilizes a TDD scheme. In some aspects, for example, as described below in connection with FIGS. 6 to 9, the UE can selectively configure transmission capabilities (e.g., antennas, drivers, RF components, etc. ) to operate using different component carriers based on the communication needs of the UE. For example, as described below in connection with FIGS. 6 and 7, a UE can utilize a transmit chain that is normally used on a first component carrier, and can (e.g., temporarily) configure that transmit chain, as one among multiple transmit chains, to transmit on a second component carrier as a MIMO transmission. In such an example, the UL throughput of the UE can be increased by increasing the number of transmit chains dedicated to transmission using the highest bandwidth communication channel (e.g., a MIMO-enabled component carrier) at times of high utilization, while at other times, the reduced UL capabilities can match the utilization of the UE without requiring dedicated additional hardware that can increase the cost of manufacturing the UE.

FIG. 4 is a schematic illustration of an organization of wireless resources in an air interface utilizing orthogonal frequency divisional multiplexing (OFDM) in accordance with some aspects of the disclosed subject matter, and is described as an illustrative example without limitation. It should be understood by those of ordinary skill in the art that the various aspects of the present disclosure can be applied to a DFT-s-OFDMA waveform in substantially the same way as described herein below. That is, while some examples of the disclosed subject matter may focus on an OFDM link for clarity, it should be understood that the same principles can be applied as well to DFT-s-OFDMA waveforms.

Within the present disclosure, a frame can refer to a duration of 10 milliseconds (ms) for wireless transmissions, with each frame including 10 subframes of 1 ms each. On a given carrier, there may be one set of frames in the UL, and another set of frames in the DL. Referring now to FIG. 4, an expanded view of an exemplary DL subframe 402 is illustrated, showing an OFDM resource grid 404. However, as those skilled in the art will readily appreciate, the PHY transmission structure for any particular application can vary from the example described here, depending on any number of factors. Here, time is in the horizontal direction with units of OFDM symbols; and frequency is in the vertical direction with units of subcarriers or tones.

Resource grid 404 can be used to schematically represent time–frequency resources for a given antenna port. That is, in a MIMO implementation with multiple antenna ports available, a corresponding multiple number of resource grids 404 can be available for communication. Resource grid 404 can be divided into multiple resource elements (REs) 406. An RE, which is 1 subcarrier × 1 symbol, is the smallest discrete part of the time–frequency grid, and contains a single complex value representing data from a physical channel or signal. Depending on the modulation utilized in a particular implementation, each RE can represent one or more bits of information. In some examples, a block of REs can be referred to as a physical resource block (PRB) or more simply a resource block (RB) 408, which contains any suitable number of consecutive subcarriers in the frequency domain. In one example, an RB can include 12 subcarriers, a number independent of the numerology used. In some examples, depending on the numerology, an RB can include any suitable number of consecutive OFDM symbols in the time domain. Within the present disclosure, unless otherwise stated, it is assumed that a single RB such as RB 408 entirely corresponds to a single direction of communication (either transmission or reception for a given device) .

A UE generally utilizes only a subset of resource grid 404. An RB can be the smallest unit of resources that can be allocated to a UE. Thus, as more RBs are scheduled for a particular UE, the modulation scheme chosen for the air interface increases, and data rates that can be achieved by the UE also increase.

In FIG. 4, RB 408 is shown as occupying less than the entire bandwidth of subframe 402, with some subcarriers illustrated above and below RB 408. In a given implementation, subframe 402 can have a bandwidth corresponding to any number of one or more RBs 408. Further, in FIG. 4, RB 408 is shown as occupying less than the entire duration of subframe 402, although this is merely one possible example.

Each subframe 402 (e.g., a 1 ms subframe) can include one or multiple adjacent slots. In the example of FIG. 4, one subframe 402 includes four slots 410, as an illustrative example. In some examples, a slot can be defined according to a specified number of OFDM symbols with a given cyclic prefix (CP) length. For example, a slot can include 7 or 14 OFDM symbols with a nominal CP. Additional examples can include mini-slots having a shorter duration (e.g., 1, 2, 4, or 7 OFDM symbols) . Such mini-slots can in some cases be transmitted occupying resources scheduled for ongoing slot transmissions for the same or for different UEs.

An expanded view of one of the slots 410 illustrates slot 410 including a control region 412 and a data region 414. In general, control region 412 can carry control channels (e.g., PDCCH) , and data region 414 can carry data channels (e.g., PDSCH or PUSCH) . Additionally or alternatively, a slot can contain various combinations of DL and UL, such as all DL, all UL, or at least one DL portion and at least one UL portion. The simple structure illustrated in FIG. 4 is merely exemplary in nature, and different slot structures can be utilized, and can include one or more of each of the control region (s) and data region (s) .

Although not illustrated in FIG. 4, various REs 406 within an RB 408 can be scheduled to carry one or more physical channels, including control channels, shared channels, data channels, etc. Other REs 406 within RB 408 can also carry pilot signals and/or reference signals. These pilot signals and/or reference signals can facilitate performance of channel estimation of the corresponding channel by a receiving device, which can enable coherent demodulation/detection of the control and/or data channels within RB 408.

In a DL transmission, the transmitting device (e.g., the base station 108) can allocate one or more REs 406 (e.g., within a control region 412) to carry DL control information (e.g., downlink control information 114 described above in connection with FIG. 1) including one or more DL control channels that generally carry information originating from higher layers, such as a physical broadcast channel (PBCH) , a physical downlink control channel (PDCCH) , etc., to one or more scheduled entities (e.g., a particular UE 106) . In addition, DL REs can be allocated to carry DL physical signals that generally do not carry information originating from higher layers. These DL physical signals can include a primary synchronization signal (PSS) ; a secondary synchronization signal (SSS) ; demodulation reference signals (DM-RS) ; phase-tracking reference signals (PT-RS) ; channel-state information reference signals (CSI-RS) ; etc.

The synchronization signals PSS and SSS (collectively referred to as SS) , and in some examples, the PBCH, can be transmitted in an SS block that includes 4 consecutive OFDM symbols (e.g., numbered via a time index in increasing order from 0 to 3) . In the frequency domain, the SS block can extend over 240 contiguous subcarriers, with the subcarriers being numbered via a frequency index in increasing order from 0 to 239. Of course, the disclosed subject matter is not limited to this specific SS block configuration. Other nonlimiting examples can utilize greater or fewer than two synchronization signals; can include one or more supplemental channels in addition to the PBCH; can omit a PBCH; and/or can utilize nonconsecutive symbols for an SS block, without departing from the scope of the present disclosure.

The PDCCH can carry downlink control information (DCI) for one or more UEs in a cell. This can include, but is not limited to, power control commands, scheduling information, a grant, and/or an assignment of REs for DL and UL transmissions.

In a UL transmission, a transmitting device (e.g., UE 106) can utilize one or more REs 406 to carry UL control information (UCI) (e.g., uplink control information 118 described above in connection with FIG. 1) . The UCI can originate from higher layers via one or more UL control channels, such as a physical uplink control channel (PUCCH) , a physical random access channel (PRACH) , etc., to the scheduling entity (e.g., base station 108) . Further, UL REs may carry UL physical signals that generally do not carry information originating from higher layers, such as demodulation reference signals (DM-RS) , phase-tracking reference signals (PT-RS) , sounding reference signals (SRS) , etc. In some examples, the control information (e.g., uplink control information 118) can include a scheduling request (SR) , i.e., a request for the scheduling entity 108 to schedule uplink transmissions. Here, in response to the SR transmitted on a control channel (e.g., over which uplink control information 118 is transmitted) , the scheduling entity (e.g., base station 108) can transmit downlink control information (e.g., downlink control information 114) that can schedule resources for uplink packet transmissions.

UL control information can also include hybrid automatic repeat request (HARQ) feedback such as an acknowledgment (ACK) or negative acknowledgment (NACK) , channel state information (CSI) , and/or any other suitable UL control information. HARQ is a technique well-known to those of ordinary skill in the art, in which the integrity of packet transmissions can be checked at the receiving side for accuracy, e.g., utilizing any suitable integrity checking mechanism, such as a checksum or a cyclic redundancy check (CRC) . If the integrity of the transmission confirmed, an ACK can be transmitted, whereas if not confirmed, a NACK can be transmitted. In response to a NACK, the transmitting device can send a HARQ retransmission, which can implement chase combining, incremental redundancy, etc.

In addition to control information, one or more REs 406 (e.g., within the data region 414) can be allocated for user data or traffic data. Such traffic can be carried on one or more traffic channels, such as, for a DL transmission, a physical downlink shared channel (PDSCH) ; or for an UL transmission, a physical uplink shared channel (PUSCH) .

In order for a UE to gain initial access to a cell, the RAN (e.g., RAN 104, 200) can provide system information (SI) characterizing the cell. This system information can be provided utilizing minimum system information (MSI) , and other system information (OSI) . The MSI can be periodically broadcast over the cell to provide the most basic information required for initial cell access, and for acquiring any OSI that may be broadcast periodically or sent on-demand. In some examples, the MSI can be provided over two different downlink channels. For example, the PBCH can carry a master information block (MIB) , and the PDSCH can carry a system information block type 1 (SIB1) , which is sometimes referred to as the remaining minimum system information (RMSI) .

OSI can include any SI that is not broadcast in the MSI. In some examples, the PDSCH can carry multiple SIBs, not limited to SIB1, described above. Here, the OSI can be provided in these SIBs, e.g., SIB2 and/or above.

The channels or carriers described above and illustrated in FIGS. 1 and 4 are not necessarily all the channels or carriers that can be utilized between a scheduling entity (e.g., base station 108) and scheduled entities (e.g., UEs 106) , and those of ordinary skill in the art will recognize that other channels or carriers can be utilized in addition to those illustrated, such as other traffic, control, and feedback channels.

These physical channels described above are generally multiplexed and mapped to transport channels for handling at the medium access control (MAC) layer. Transport channels carry blocks of information called transport blocks (TB) . The transport block size (TBS) , which can correspond to a number of bits of information, can be a controlled parameter, based on the modulation and coding scheme (MCS) and the number of RBs in a given transmission.

According to an aspect of the disclosure, one or more slots can be structured as self-contained slots. For example, FIG. 5 is a schematic illustration of exemplary self-contained

slots

500 and 550 in accordance with some aspects of the disclosed subject matter, and is described as an illustrative example without limitation. In some aspects, self-contained slots 500 and/or 550 can be used, in some examples, in place of slot 410 described above in connection with, and illustrated in, FIG. 4.

In FIG. 5, slot 500 is an example of a DL-centric slot, which can be a slot scheduled by the device transmitting the data that is the subject of the DL (e.g., scheduled by a base station, such as base station 108) . The nomenclature DL-centric can generally refer to a structure in which more resources are allocated for transmissions in the DL direction (e.g., transmissions from a scheduling entity, such as base station 108, to a scheduled entity, such as UE 106) . Slot 550 is an example of UL-centric slot, which can be scheduled by the device transmitting data that is the subject of the UL (e.g., scheduled by a UE, such as UE 108) , in which more resources are allocated for transmissions in the UL direction (e.g., transmissions from a scheduled entity, such as UE 106, to a scheduling entity, such as base station 108) .

Each slot, such as the self-contained

slots

500 and 550, can include transmit (Tx) and receive (Rx) portions. For example, in DL-centric slot 500, the scheduling entity first has an opportunity to transmit control information, e.g., on a PDCCH, in a DL control region 502, and then an opportunity to transmit DL user data or traffic, e.g., on a PDSCH, in a DL data region 504. Following a guard period (GP) region 506 having a suitable duration, the scheduling entity has an opportunity to receive UL data and/or UL feedback including any UL scheduling requests, CSF, a HARQ ACK/NACK, etc., in a UL burst 508 from other entities using the carrier. Here, a slot such as DL-centric slot 500 can be referred to as a self-contained slot when all of the data carried in the data region 504 is scheduled in the control region 502 of the same slot; and further, when all of the data carried in the data region 504 is acknowledged (or at least has an opportunity to be acknowledged) in the UL burst 508 of the same slot. In this way, each self-contained slot can be considered a self-contained entity, not necessarily requiring any other slot to complete a scheduling-transmission-acknowledgment cycle for any given packet.

In some examples, GP region 506 can be included to accommodate variability in UL and DL timing. For example, latencies due to radio frequency (RF) antenna direction switching (e.g., from DL to UL) and transmission path latencies can cause the scheduled entity (e.g., UE 106) to transmit early on the UL to match DL timing. In some examples, such early transmission can interfere with symbols received from the scheduling entity (e.g., base station 108) . Accordingly, GP region 506 can allow an amount of time after DL data region 504 to prevent interference, where the GP region 506 provides an appropriate amount of time for the scheduling entity to switch its RF antenna direction, an appropriate amount of time for the over-the-air (OTA) transmission, and/or an appropriate amount of time for ACK processing by the scheduled entity.

Similarly, UL-centric slot 550 can be configured as a self-contained slot. In some examples, UL-centric slot 550 can be substantially similar to DL-centric slot 500, including a guard period 554 (e.g., similar to GP 504) , an UL data region 556 (e.g., a counterpart to DL data region 504) , and an UL burst region 558 (e.g., similar to UL burst region 508) .

Note that the slot structure illustrated in

slots

500 and 550 is merely one example of self-contained slots. Other examples can include a common DL portion at the beginning of every slot, and a common UL portion at the end of every slot, with various differences in the structure of the slot between these respective portions. Other examples still can be provided within the scope of the present disclosure.

FIG. 6 is a schematic illustration of timing in a process for uplink transmit switching across carrier aggregation component carriers in accordance with some aspects of the disclosed subject matter, and is described as an illustrative example without limitation. In FIG. 6, a number of slots of two different component carriers are illustrated, including a first component carrier 602 on which communications are implemented using an FDD scheme, and a second component carrier 604 on which communications are implemented using a TDD scheme. For example, component carrier 602 can correspond to band n1 (2.1 gigahertz (GHz) ) , and component carrier 604 can correspond to band n78 (3.5 Ghz) .

In some aspects, as illustrated in FIG. 6, during normal operation, component carrier 602 operates using the FDD scheme in which both a UL slot and a DL slot are utilized simultaneously, and component carrier 604 operates using the TDD scheme in which each slot is a DL slot or an UL slot. In FIG. 6, a DL slot is labeled as D, and an UL slot is labeled as U. In this illustration, a slot on the TDD CC labeled S is a 'special' slot, which can be utilized for a transition from downlink to uplink slots on a TDD carrier. Here, any given slot on the TDD carrier can be a self-contained slot, as described above in connection with, and illustrated in, FIG. 5, with a DL slot corresponding to a DL-centric slot, and an UL slot corresponding to an UL-centric slot. However, this is not necessarily the case. In other non-limiting examples, a DL slot on the TDD carrier in FIG. 6 can refer to a slot that is DL-centric, entirely DL, etc. Similarly, an UL slot on the TDD carrier in FIG. 6 can refer to a slot that is UL-centric, entirely UL, etc.

As illustrated in FIG. 6, in some aspects, during a time when a UE is expected to have a high UL utilization, the base station can initiate a 1 Tx to 2 Tx switching feature in which component carrier 604 operates using two Tx chains, which can increase the total UL throughput of the UE due to TDD band (component carrier 604) being associated with much larger bandwidth (e.g., 100 MHz) compared with the FDD band of component carrier 602 (e.g., 20 MHz) In some aspects, one UL Tx can be available for use by either component carrier 602 (FDD) or component carrier 604 (TDD) , such that component carrier 602 is usually associated with 1 Tx chain or 0 Tx chains, and component carrier 604 is usually associated with 1 Tx chain or 2 Tx chaines.

In some aspects, when performing a 1 Tx to 2 Tx switching feature, a transient time gap 606 on the DL subcarrier of the FDD component carrier 602 can be specified during which the UE should not expect any scheduled Tx or Rx. In some aspects, the placement of the gap 606 can be specified by a base station (e.g., explicitly based on a Radio Resource Control (RRC) protocol, defined in 3GPP TS 38.331 version 16.0.0 Release 16) , and can be semi-statically configured on one specific carrier of the two possible uplink carriers. In a particular example, due to the time corresponding to the retuning the UL Tx chain, the base station can place gap 606 in the FDD component carrier 602. Note that although gap 606 is placed in slot 2, prior to the switch boundary, this is merely an example, and gap 606 can be placed after the switch boundary. In some aspects, the placement of the gap 606 can be specified by a base station implicitly using DCI, which can configure the UE with valid time resources that take into consideration transient time gap (e.g., the transient time gap can be implicitly supplied in scheduling information provided by the base station) .

In some aspects, the base station can initiate 1 Tx to 2 Tx switching during slot 2 of the FDD component carrier 602, which can be conveyed in the DL slot received via the FDD component carrier 602 in slot 2 and/or the DL slot received via the TDD component carrier 604 in slot 4. The third decision boundary illustrated in FIG. 6 can represent the timing at which a decision to perform the 1 Tx to 2 Tx switching for an upcoming slot of component carrier 602 has to be made. As illustrated in FIG. 6, in some configurations, switching component carrier 604 to a two Tx chain UL configuration can require a change in operation of the FDD component carrier 602.

Additionally, in some aspects, due to operations associated with RF retuning involved in switching the TDD component carrier 604 from 1 Tx chain to 2 Tx chains, an additional DL interruption time 608 may be required at the FDD component carrier 602 in addition to gap 606 based on the implementation of the UE performing the switch. Note that although additional DL interruption time 608 is placed after the switch boundary and gap 606, this is merely an example, and additional DL interruption time 608 can be placed prior to the switch boundary and/or gap 606. In some aspects, a UE that is configured to perform 1 Tx to 2 Tx switching can report its capabilities regarding whether such additional DL interruption time 608 is required, and if so, how much additional time is needed. For example, the UE can report its capabilities when the UE establishes a connection with a new RAN, with a new base station, with a new sector, etc. As another example, the UE can report its capabilities periodically (e.g., at regular and/or irregular intervals) . Additionally or alternatively, in some aspects, additional DL interruption time 608 can be hard coded into the base station and/or UE based on a specification with which the devices have been configured to comply.

In some aspects, the switching can last any suitable number of slots, after which the configuration of component carrier 602 and component carrier 604 can return to a normal configuration, which can require another transient time gap 610 to switch back from the 2 Tx chain configuration to a 1 Tx chain configuration.

FIG. 7 is another schematic illustration of timing in a process for uplink transmit switching across carrier aggregation component carriers in accordance with some aspects of the disclosed subject matter, and is described as an illustrative example without limitation. In FIG. 7, a number of slots of two different component carriers are illustrated, including a first component carrier 702 on which communications are implemented using an FDD scheme (which can be the same component carrier as component carrier 602) , and a second component carrier 704 on which communications are implemented using a TDD scheme (which can be the same component carrier as component carrier 604) . As illustrated in FIG. 7, when a UE is in a 2 Tx chain configuration, the base station can initiate a transition back to a 1 Tx chain configuration at a decision boundary. For example, the base sation can determine that additional UL throughput provided by the 2 Tx chain configuration is no longer required. As another example, the base station can determine that an allotment of slots granted to the UE for 2 Tx chain operation has elapsed, and require the UE to transition back to a normal mode of operation. In some aspects, the number of slots granted to a UE can be limited to no more than a maximum number of slots (e.g., 1 slot, 2 slots, 3 slots, etc. ) , which can be specified by a standard with which the UE and/or base station has been configured to comply.

In some aspects, when performing a 2 Tx to 1 Tx switching feature, a transient time gap 706 can be specified during which the UE should not expect any scheduled Tx or Rx. In some aspects, the placement of gap 706 can be specified by a base station (e.g., based on a Radio Resource Control (RRC) protocol, defined in 3GPP TS 38.331 version 16.0.0 Release 16) , and can be semi-statically configured on one specific carrier of the two possible uplink carriers. In a particular example, due to the desirability of more fully utilizing the bandwidth of the FDD component carrier 704, the base station may place gap 706 in the TDD component carrier 702. In some aspects, the placement of the gap 706 can be specified by a base station implicitly using DCI, which can configure the UE with valid time resources that take into consideration transient time gap (e.g., the transient time gap can be implicitly supplied in scheduling information provided by the base station) .

In some aspects, the base station can initiate 2 Tx to 1 Tx switching during slot 12 of the TDD component carrier 704, which can be granted in the DL slot received via the FDD component carrier 702 in slot 6. The second decision boundary illustrated in FIG. 7 can represent the timing at which a decision to perform the 2 Tx to 1 Tx switching for an upcoming slot of the TDD component carrier 702 has to be made. As illustrated in FIG. 7, in some configurations, switching the TDD component carrier 704 to a single Tx chain UL configuration (or a zero Tx chain configuration) can require a change in operation of the FDD component carrier 702.

Additionally, in some aspects, due to operations associated with RF retuning involved in switching the TDD component carrier 704 from 1 Tx chain to 2 Tx chains, an additional DL interruption time 708 may be required for the FDD component carrier 702 in addition to gap 706 based on the implementation of the UE performing the switch. In some aspects, a UE that is configured to perform 2 Tx to 1 Tx switching can report its capabilities regarding whether additional DL interruption is required when switching an UL Tx chain to the FDD component carrier 702, and if so, how much additional time is needed. For example, the UE can report its capabilities when the UE establishes a connection with a new RAN, with a new base station, with a new sector, etc. As another example, the UE can report its capabilities periodically (e.g., at regular and/or irregular intervals) . Additionally or alternatively, in some aspects, additional DL interruption time 708 can be hard coded into the base station and/or UE based on a specification with which the devices have been configured to comply.

FIG. 8 is a flow chart illustrating an exemplary process 800 for uplink transmit switching across carrier aggregation component carriers by a user equipment in accordance with some aspects of the disclosed subject matter, and is described as an illustrative example without limitation. As described below, some or all illustrated features can be omitted in a particular implementation within the scope of the disclosed subject matter, and some illustrated features may not be required for implementation of all embodiments. In some examples, process 800 can be carried out (e.g., executed) by user equipment described below in connection with FIG. 11, and/or UE 106 described above in connection with FIG. 1. In some examples, process 800 can be carried out by any suitable apparatus or means for carrying out the functions or algorithm described below.

At 802, a UE can establish a connection with a base station associated with a particular frequency band. For example, as described above in connection with FIG. 6, a UE can establish a connection with a base station using band n1 and/or band n78, etc. In some aspects, the UE can use any suitable technique or combination of techniques to establish a connection with the base station, which can occur during a handover and/or when a UE carrying out process 800 becomes active (e.g., from an inactive state such as a powered down state, a state in which connections are inhibited, etc. ) .

At 804, the UE can provide UE configuration information that can include information about various capabilities of the UE. For example, the UE configuration information can include UE capability information that includes an indication of whether the UE is configured to perform 1 Tx to 2 Tx switching. As another example, the UE capability information can include an indication of whether additional DL interruption time is needed during a 1 Tx to 2 Tx switching.

As yet another example, the UE capability information can include an indication of how much additional DL interruption time the UE needs. In a more particular example, the amount of additional DL interruption time can be specified as a selection from a discrete number of values (e.g., a selection of one of two values, using a single bit, a selection of one of four values using two bits, etc. ) . As another more particular example, the amount of additional DL interruption time can be specified as a number of OFDM symbols (e.g., an integer number of symbols based on the numerology of the band to which the UE has established a connection) . As still another more particular example, the amount of additional DL interruption time can be specified as a number of samples (e.g., an integer number of samples based on the frequency of the band to which the UE has established a connection) . As a further more particular example, the amount of additional DL interruption time can be specified as a floating point number (e.g., in microseconds) . In some aspects, the UE can calculate whether the transient time provided via the standard (e.g. gap 606) for the particular band is sufficient for the UE to perform an UL transmit switching operation, and if not, which of one or more additional DL interruption times that can be selected (if the values are pre-selected) , is sufficient to perform the operation.

As still another example, the UE capability information can include an indication of whether the additional time is needed when the UL Tx chain is being transferred "from" the CC (e.g., from the FDD component carrier for use by the TDD component carrier) , when the UL Tx chain is being transferred "to" the CC (e.g., back to the FDD component carrier) , or both "from" and "to. " In a more particular example, the UE capability information can include an indication of whether the additional time is needed "from, " "to, " or "both" using two bits (e.g., 01 for "to, " 10 for "from, " and 11 for both) . Note that in accordance with the subject matter disclosed herein, TDD component carriers can be configured to not require additional DL interruption time. In some aspects, if different times are required for from and to, the different times can be reported in addition to information indicating whether the additional DL interruption time is needed, or in lieu of the information (e.g., the separate times can be used to indicate whether time is needed for "from" and "to, " and how much time is needed) .

At 806, the UE can receive an indication (e.g., from the base station) indicating that an uplink transmit switching operation is to be performed. For example, a UE can determine whether a request to initiate a particular uplink transmit switching operation has been received from the base station. Note that in some aspects, the request can be received directly form the base station responsible for making scheduling determination, or indirectly via another network node, such as another base station to which the UE is connected, etc.

If the UE determines that initiation of UL switching is not currently indicated ( "NO" at 808) , process 800 can move to 812, and the UE can determine whether handover to a new base station is appropriate (e.g. as described above in connection with FIG. 2) .

Otherwise, if the UE determines that initiation of UL switching is currently indicated ( "YES" at 808) , process 800 can move to 810. At 810, the UE can utilize a transient time and any additional time scheduled by a base station based on the UE configuration information provided at 804 to perform operations associated with UL Tx switching. For example, as described above in connection with FIGS. 6 and 7, a UE can utilize a gap (e.g., gap 606 or gap 706) scheduled by a base station and/or any additional DL interruption time (e.g., additional DL interruption time 608 or additional DL interruption time 708) scheduled by the base station.

At 812, a UE can determine whether a handover to a new base station is indicated (e.g., based on considerations described above in connection with FIG. 2) . If the UE determines that a handover is not indicated ( "NO" at 812) , process 800 can return to 806. Otherwise, if the UE determines that a handover is not indicated ( "NO" at 812) , process 800 can end (e.g., and begin at 802 at the new base station) .

FIG. 9 is a flow chart illustrating an exemplary process for uplink transmit switching across carrier aggregation component carriers by a base station in accordance with some aspects of the disclosed subject matter, and is described as an illustrative example without limitation. As described below, some or all illustrated features can be omitted in a particular implementation within the scope of the disclosed subject matter, and some illustrated features may not be required for implementation of all embodiments. In some examples, process 900 can be carried out (e.g., executed) by a base station described below in connection with FIG. 10, and/or base station 108 described above in connection with FIG. 1. In some examples, process 900 can be carried out by any suitable apparatus or means for carrying out the functions or algorithm described below.

At 902, a base station can establish a connection with a UE using a particular frequency band. For example, as described above in connection with FIG. 6, a base station can establish a connection with a UE using band n1 and/or band n78, etc. In some aspects, a base station can use any suitable technique or combination of techniques to establish a connection with the UE, which can occur during a handover and/or when a UE becomes active (e.g., from an inactive state such as a powered down state, a state in which connections are inhibited, etc. ) .

At 904, a base station can receive UE configuration information that can include information about various capabilities of the UE. For example, the UE configuration information can include UE capability information described above in connection with 804 of FIG. 8. In some aspects, a base station can cause the UE configuration information to be recorded (e.g., in connection with identifying information of the UE) .

At 906, a base station can determine whether to initiate an uplink transmit switching operation.

In some aspects, if the UE is currently in a configuration in which 1 Tx chain (or 0 Tx chains) are being used by a high bandwidth component carrier configured to use a TDD scheme, and 1 Tx chain is being used by a lower bandwidth component carrier configured to use an FDD scheme, the base station can determine whether the UE is in a high UL utilization period and/or is entering a high UL utilization period. In some aspects, the base station can determine whether the UE is in a high UL utilization period and/or is entering a high UL utilization period using any suitable technique or combination of techniques.

Additionally or alternatively, if the UE is currently in a configuration in which 2 Tx chains are being used by a high bandwidth component carrier configured to use a TDD scheme, and 0 Tx chains are being used by a lower bandwidth component carrier configured to use an FDD scheme, the base station can determine whether the UE is scheduled to transition back from the current configuration and/or whether the UE has entered a lower UL utilization period.

If a base station determines that an uplink transmit switching operation is not to be initiated ( "NO" at 906) , process 900 can move to 908, and a base station can schedule DL slots to the UE for upcoming slots normally. Otherwise, if a base station determines that an uplink transmit switching operation is to be initiated ( "YES" at 906) , the base station can transmit an indication the UE to initiate the uplink transmit switching operation, and can move to 910.

At 910, a base station can receive an indication that UL transmit switching has been initiated for a particular upcoming slot (e.g., in a particular band) . In some aspects, a base station can determine whether to grant UL slots to the UE (e.g., based on demand, QoS, etc. ) . For the sake of simplicity, process 900 is described with the assumption that UL slots are granted, and that the UL transmit switching is carried out. However, if a base station determines that UL slots are not available, process 900 can return to 906.

At 912, a base station can schedule one or more upcoming DL slots for the UE based on the UE configuration information received at 904 and the indication that uplink transmit switching has been initiated.

In some aspects, a base station can schedule a transient time gap (e.g., gap 606, gap 706) at a switch boundary (e.g., at the end of a slot preceding the switch, at the beginning of a slot after the switch) . Additionally, in some aspects, a base station can schedule an additional DL interruption time (e.g., additional DL interruption time 608, additional DL interruption time 708) based on the UE configuration information received at 904, such as whether such an additional DL interruption time is necessary, the direction of the switch (e.g., whether an UL Tx chain is being transferred "to" or "from" the band associated with the base station executing process 900) , and the amount of time required (e.g., in symbols, samples, microseconds, etc. ) . In some aspects, a base station can inhibit transmission of data or otherwise refrain from transmitting data to the UE during what would ordinarily be a DL slot when the base station has designated that time as a transient gap and/or as an additional DL interruption time.

In some aspects, a base station can determine whether the additional DL interruption time is at least equal to one slot length in the numerology of the band for which the additional DL interruption time is being added. If the additional DL interruption time is equal to or greater than 1 slot, a base station can add 1 to K0 (e.g., for each slot length exceeded by the additional DL interruption time) .

In some aspects, a base station can use any remaining symbols or portion of symbols after removing any whole slot lengths from the additional DL interruption time (e.g., by performing a modulo operation using the symbol length used by the band on which the additional DL interruption time is to be added) to adjust a SLIV value used to indicate when a beginning of a data download is to begin within a specified slot (e.g., specified at least in part by K0) . For example, SLIV can specify a start symbol "S" at which data reception is scheduled to begin for a specified slot, and a length "L" in symbols of the scheduled data transmission for the specified slot.

In some aspects, if both the transient time (e.g., gap 606) and at least a portion of the additional DL interruption time are to be included in a single slot, then the combined length of S and L should comply with the following relationship: S+L≤14- (TT+ DI) , where TT is the length of the gap in symbols, and DI is the length of the additional DL interruption time in symbols. In some examples, if the gap and additional DL interruption time are included at the beginning of the slot, S should be equal to or greater than TT+DI. Alternatively, in some examples, if the gap and additional DL interruption time are included at the end of the slot, S+L should be less than 14- (TT+DI) .

In some aspects, if the transient time (e.g., gap 606) and at least a portion of the additional DL interruption time are in a different slot (e.g., likely with the transient time at the end of a slot, and the additional DL interruption time at the beginning of the next) , then for the first slot the combined length of S and L should comply with the relationship S+L≤14-TT, while for the second slot the the combined length of S and L should comply with the relationship S+L≤14-DI, and S should be greater than or equal to DI.

In some aspects, a base station can provide one or more SLIV values (e.g., associated with one or more upcoming slots) to the UE to indicate when data download in a DL slot is scheduled. Using the illustration of FIG. 6 as an example, after a UL transmit switching operation is initiated during slot 2 of component carrier 602, a base station can calculate SLIV for slot 3, and can provide the SLIV value for slot 3 during DL slot 2, such that the UE can determine when to expect DL data in slot 3.

At 914, a base station can determine whether a handover to a new base station is indicated (e.g., based on considerations described above in connection with FIG. 2) . If a base station determines that a handover is not indicated ( "NO" at 914) , process 900 can return to 906. Otherwise, if a base station determines that a handover is not indicated ( "NO" at 914) , process 900 can end (e.g., and begin at 902 when a new UE connects to the base station) .

FIG. 10 is a block diagram conceptually illustrating an example of a hardware implementation for a scheduling entity 1000 in accordance with some aspects of the disclosed subject matter, and is described as an illustrative example without limitation... For example, scheduling entity 1000 can be a user equipment (UE) as illustrated in any one or more of FIGS. 1, 2, and/or 3. In another example, scheduling entity 1000 can be a base station as illustrated in any one or more of FIGS. 1, 2, and/or 3.

In some aspects, scheduling entity 1000 can be implemented with a processing system 1014 that includes one or more processors 1004. Examples of processors 1004 include central processing units (CPUs) , microprocessors, microcontrollers, digital signal processors (DSPs) , field programmable gate arrays (FPGAs) , programmable logic devices (PLDs) , graphics processing units (GPUs) , state machines, gated logic, discrete hardware circuits, and other suitable hardware configured to perform the various functionality described throughout this disclosure. In various examples, scheduling entity 1000 can be configured to perform any one or more of the functions described herein. That is, processor 1004, as utilized in scheduling entity 1000, can be used to implement any one or more of the processes and procedures described above in connection with FIGS. 8 and 9.

In this example, processing system 1014 can be implemented with a bus architecture, represented generally by the bus 1002. Bus 1002 can include any number of interconnecting buses and bridges depending on the specific application of processing system 1014 and the overall design constraints. Bus 1002 can communicatively couple together various circuits including one or more processors (represented generally by processor 1004) , memory 1005, and computer-readable media (represented generally by computer-readable medium 1006) . Bus 1002 can also link various other circuits such as timing sources, peripherals, voltage regulators, and power management circuits, which are well known in the art, and therefore, will not be described any further. A bus interface 1008 can provide an interface between bus 1002 and a transceiver 1010. Transceiver 1010 can provide a communication interface or means for communicating with various other apparatus over a transmission medium. Depending upon the nature of the apparatus, a user interface 1012 (e.g., keypad, display, speaker, microphone, joystick) can also be provided. Of course, such a user interface 1012 can be omitted in some examples, such as a base station.

In some aspects of the disclosed subject matter, processor 1004 can include DL scheduling circuitry 1040 configured for various functions, including, for example, scheduling the start time of downlink transmissions to a scheduled entity (e.g., a UE) with various slots, and the length of time of the data transmission (e.g., using SLIV) . For example, DL scheduling circuitry 1040 can be configured to implement one or more of the functions described above in connection with FIG. 9, such as functions described in connection with 908 and/or 912. Additionally, in some aspects, processor 1004 can include DI calculation circuitry 1042 configured for various functions, including, for example, determining a length of time, in symbols, of an additional DL interruption needed by a particular UE to perform an uplink transmit switching on a given band associated with scheduling entity 1000. For example, DI calculation circuitry 1042 can be configured to implement one or more of the functions described above in connection with FIG. 9, such as functions described in connection with 912.

Processor 1004 can manage bus 1002 and can perform general processing, including the execution of software stored on computer-readable medium 1006, which, when executed by processor 1004, causes processing system 1014 to perform the various functions described above (e.g., in connection with FIGS. 8 and 9) for any particular apparatus. In some aspects, computer-readable medium 1006 and memory 1005 can also be used for storing data that is manipulated by processor 1004 when executing software.

One or more processors 1004 in the processing system can execute software. Software shall be construed broadly to mean instructions, instruction sets, code, code segments, program code, programs, subprograms, software modules, applications, software applications, software packages, routines, subroutines, objects, executables, threads of execution, procedures, functions, etc., whether referred to as software, firmware, middleware, microcode, hardware description language, or otherwise. The software can reside on a computer-readable medium 1006. The computer-readable medium 1006 can be a non-transitory computer-readable medium. A non-transitory computer-readable medium includes, by way of example, a magnetic storage device (e.g., hard disk, floppy disk, magnetic strip) , an optical disk (e.g., a compact disc (CD) or a digital versatile disc (DVD) ) , a smart card, a flash memory device (e.g., a card, a stick, or a key drive) , a random access memory (RAM) , a read only memory (ROM) , a programmable ROM (PROM) , an erasable PROM (EPROM) , an electrically erasable PROM (EEPROM) , a register, a removable disk, and any other suitable medium for storing software and/or instructions that can be accessed and read by a computer. The computer-readable medium 1006 can reside in the processing system 1014, external to the processing system 1014, or distributed across multiple entities including the processing system 1014. The computer-readable medium 1006 can be embodied in a computer program product. By way of example, a computer program product can include a computer-readable medium in packaging materials. Those skilled in the art will recognize how best to implement the described functionality presented throughout this disclosure depending on the particular application and the overall design constraints imposed on the overall system.

In one or more examples, computer-readable storage medium 1006 can include DL scheduling software 1052 configured for various functions, including, for example, scheduling the start time of downlink transmissions to a scheduled entity (e.g., a UE) with various slots, and the length of time of the data transmission (e.g., using SLIV) . For example, DL scheduling software 1052 can be configured to implement one or more of the functions described above in relation to FIG. 9, such as functions described in connection with 908 and/or 912. Additionally, in some aspects, computer-readable storage medium 1006 can include DI calculation software 1054 configured for various functions, including, for example, determining a length of time, in symbols, of an additional DL interruption needed by a particular UE to perform an uplink transmit switching on a given band associated with scheduling entity 1000. For example, DI calculation software 1054 can be configured to implement one or more of the functions described above in connection with FIG. 9, such as functions described in connection with 912.

FIG. 11 is a block diagram conceptually illustrating an example of a hardware implementation for a scheduled entity 1100 in accordance with some aspects of the disclosed subject matter, and is described as an illustrative example without limitation. For example, scheduled entity 1100 can be a user equipment (UE) as illustrated in any one or more of FIGS. 1, 2, and/or 3. In accordance with some aspects of the disclosure, an element, or any portion of an element, or any combination of elements can be implemented with a processing system 1114 that includes one or more processors 1104.

In some aspects, processing system 1114 can be substantially the same as the processing system 1014 illustrated in FIG. 10, including a bus interface 1108, a bus 1102, memory 1105, processor 1104, and a computer-readable medium 1106. Furthermore, scheduled entity 1100 can include a user interface 1112 and a transceiver 1110 substantially similar to those described above in FIG. 10. That is, processor 1104, as utilized in a scheduled entity 1100, can be used to implement any one or more of the processes described above in connection with, and illustrated in, FIG. 8.

In some aspects of the disclosure, processor 1104 can include DL interruption calculation circuitry 1140 configured for various functions, including, for example, determine a time period of an additional DL interruption time needed for uplink transmit switching based on the band the scheduled entity is utilizing. For example, DL interruption calculation circuitry 1140 can be configured to implement one or more of the functions described above in connection with FIG. 8, such as functions described in connection with 804. Additionally, in some aspects, processor 1104 can include UL switching circuitry 1142 configured for various functions, including, for example, determining that an UL switching operation has been initiated by a base station, and performing the UL switching operation. For example, UL switching circuitry 1142 can be configured to implement one or more of the functions described above in connection with FIG. 8, such as functions described in connection with 806 to 812.

In one or more examples, computer-readable storage medium 1106 can include DL interruption calculation software 1152 configured for various functions, including, for example, determine a time period of an additional DL interruption time needed for uplink transmit switching based on the band the scheduled entity is utilizing. For example, DL interruption calculation software 1152 can be configured to implement one or more of the functions described above in relation to FIG. 8, such as functions described in connection with 804. Additionally, in some aspects, computer-readable storage medium 1106 can include UL switching software 1154 configured for various functions, including, for example, determining that an UL switching operation has been initiated by a base station, and performing the UL switching operation. For example, UL switching software 1154 can be configured to implement one or more of the functions described above in connection with FIG. 8, such as functions described in connection with 806 to 812.

Example 1: A method, apparatus, and non-transitory computer-readable medium for wireless communication, comprising: establishing, by a user equipment, a connection with a base station on a component carrier that utilizes frequency division duplexing; providing, to the base station, user equipment capability information including a downlink interruption time needed to complete an uplink transmit switching operation in connection with a second component carrier that utilizes time division duplexing; transmitting, during a first period of time, data to the base station utilizing a first transmit chain on the first component carrier; receiving, during the first period of time, data using the second component carrier; receiving a SLIV value indicative of a start symbol value S for which the base station has scheduled a next downlink to start in relation to a beginning of the upcoming slot; determining, based on the start value, that downlink using the first component carrier is scheduled to be inhibited for a contiguous period of time equal to or greater than a sum of a transient time and the downlink interruption time; and receiving, during the upcoming slot, data using the first component carrier beginning at a symbol associated with the start value.

Example 2: A method, apparatus, and non-transitory computer-readable medium of Example 1, comprising uploading, during a second period of time coinciding at least in part with the upcoming slot, data using the second component carrier using the first transmit chain on the second component carrier and a second transmit chain on the second component carrier, wherein uploading via the first component carrier is inhibited during the second period of time.

Example 3: A method, apparatus, and non-transitory computer-readable medium of any one of Examples 1 to 2, wherein the downlink interruption time is longer than a slot length on the first component carrier, and wherein the SLIV value received during the first slot is associated with a K0 value greater than 0.

Example 4: A method, apparatus, and non-transitory computer-readable medium of any one of Examples 1 to 3, wherein the downlink interruption time is less than or equal to the sum of the slot length and S.

Example 5: A method, apparatus, and non-transitory computer-readable medium of any one of Examples 1 to 4, wherein the first component carrier corresponds to band n1 and the second component carrier corresponds to band n78.

Example 6: A method, apparatus, and non-transitory computer-readable medium of any one of Examples 1 to 5, comprising: establishing, by a base station, a connection with a user equipment on a component carrier that utilizes frequency division duplexing; receiving, from the user equipment, user equipment capability information including an downlink interruption time needed to complete an uplink transmit switching operation in connection with a second component carrier that utilizes time division duplexing; receiving, during a first period of time, data from the user equipment transmitted utilizing a first transmit chain on the first component carrier; transmitting, to the user equipment, an indication that an uplink switching operation has been initiated for an upcoming slot associated with the first component carrier; determining, based on the additional downlink interruption time and a transient time, a starting symbol at which to schedule a next downlink to the user equipment in relation to a beginning of the upcoming slot; providing, to the user equipment, a SLIV value indicative of a start symbol value S corresponding to the symbol at which the next downlink to the user equipment is scheduled to start; inhibiting transmission of data to the user equipment using the first component carrier from at least the beginning of the upcoming slot until the starting symbol indicated by the SLIV value; and transmitting, during the upcoming slot, data using the first component carrier beginning at a symbol associated with the start value.

Example 7: A method, apparatus, and non-transitory computer-readable medium of any one of Examples 1 to 6, further comprising: determining that the downlink interruption time is longer than a slot length on the first component carrier, and in response to determining that the downlink interruption time is longer than a slot length on the first component carrier, increasing a value of K0 associated with the SLIV value sent during the first slot.

Example 8: A method, apparatus, and non-transitory computer-readable medium of any one of Examples 1 to 7, wherein the additional downlink interruption time is less than or equal to the sum of the slot length and S.

Example 9: A method, apparatus, and non-transitory computer-readable medium of any one of Examples 1 to 8, wherein the first component carrier corresponds to band n1 and the second component carrier corresponds to band n78.

Example 10: A method, apparatus, and non-transitory computer-readable medium, comprising: establishing, by a base station, a connection with a user equipment on a component carrier that utilizes frequency division duplexing; receiving, from the user equipment, user equipment capability information including an downlink interruption time needed to complete an uplink transmit switching operation in connection with a second component carrier that utilizes time division duplexing; receiving, during a first period of time, data from the user equipment transmitted utilizing a first transmit chain on the first component carrier; transmitting, to the user equipment, an indication that an uplink switching operation has been initiated for an upcoming slot associated with the first component carrier; ; determining, based on the downlink interruption time and a transient time, a starting symbol at which to schedule a next downlink to the user equipment in relation to a beginning of the upcoming slot; providing, to the user equipment, a SLIV value indicative of a start symbol value S corresponding to the symbol at which the next downlink to the user equipment is scheduled to start; inhibiting transmission of data to the user equipment using the first component carrier from at least the beginning of the upcoming slot until the starting symbol indicated by the SLIV value; and transmitting, during the upcoming slot, data using the first component carrier beginning at a symbol associated with the start value.

Example 11: A method, apparatus, and non-transitory computer-readable medium of Example 10, further comprising: determining that the downlink interruption time is longer than a slot length on the first component carrier, and in response to determining that the downlink interruption time is longer than a slot length on the first component carrier, increasing a value of K0 associated with the SLIV value sent during the first slot.

Example 12: A method, apparatus, and non-transitory computer-readable medium of any one of Examples 10 to 11, wherein the downlink interruption time is less than or equal to the sum of the slot length and S.

Example 13: A method, apparatus, and non-transitory computer-readable medium of any one of Examples 10 to 12, wherein the first component carrier corresponds to band n1 and the second component carrier corresponds to band n78.

Several aspects of a wireless communication network have been presented with reference to an exemplary implementation. As those skilled in the art will readily appreciate, various aspects described throughout this disclosure may be extended to other telecommunication systems, network architectures and communication standards.

By way of example, various aspects may be implemented within other systems defined by 3GPP, such as Long-Term Evolution (LTE) , the Evolved Packet System (EPS) , the Universal Mobile Telecommunication System (UMTS) , and/or the Global System for Mobile (GSM) . Various aspects may also be extended to systems defined by the 3rd Generation Partnership Project 2 (3GPP2) , such as CDMA2000 and/or Evolution-Data Optimized (EV-DO) . Other examples may be implemented within systems employing IEEE 802.11 (Wi-Fi) , IEEE 802.16 (WiMAX) , IEEE 802.20, Ultra-Wideband (UWB) , Bluetooth, and/or other suitable systems. The actual telecommunication standard, network architecture, and/or communication standard employed will depend on the specific application and the overall design constraints imposed on the system.

Within the present disclosure, the word "exemplary" is used to mean "serving as an example, instance, or illustration. " Any implementation or aspect described herein as "exemplary" is not necessarily to be construed as preferred or advantageous over other aspects of the disclosure. Likewise, the term "aspects" does not require that all aspects of the disclosure include the discussed feature, advantage or mode of operation. The term "coupled" is used herein to refer to the direct or indirect coupling between two objects. For example, if object A physically touches object B, and object B touches object C, then objects A and C may still be considered coupled to one another-even if they do not directly physically touch each other. For instance, a first object may be coupled to a second object even though the first object is never directly physically in contact with the second object. The terms "circuit" and "circuitry" are used broadly, and intended to include both hardware implementations of electrical devices and conductors that, when connected and configured, enable the performance of the functions described in the present disclosure, without limitation as to the type of electronic circuits, as well as software implementations of information and instructions that, when executed by a processor, enable the performance of the functions described in the present disclosure.

One or more of the components, steps, features and/or functions illustrated in FIGS. 1–11 can be rearranged and/or combined into a single component, step, feature or function or embodied in several components, steps, or functions. Additional elements, components, steps, and/or functions can also be added without departing from novel features disclosed herein. The apparatus, devices, and/or components illustrated in FIGS. 1–11 can be configured to perform one or more of the methods, features, or steps described herein. The novel algorithms described herein can also be efficiently implemented in software and/or embedded in hardware.

It is to be understood that the specific order or hierarchy of steps in the methods disclosed is an illustration of exemplary processes. Based upon design preferences, it is understood that the specific order or hierarchy of steps in the methods can be rearranged. The accompanying method claims present elements of the various steps in a sample order, and are not meant to be limited to the specific order or hierarchy presented unless specifically recited therein.

The previous description is provided to enable any person skilled in the art to practice the various aspects described herein. Various modifications to these aspects will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other aspects. Thus, the claims are not intended to be limited to the aspects shown herein, but are to be accorded the full scope consistent with the language of the claims, wherein reference to an element in the singular is not intended to mean "one and only one" unless specifically so stated, but rather "one or more. " Unless specifically stated otherwise, the term "some" refers to one or more. 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 and b; a and c; b and c; and a, b and c. All structural and functional equivalents to the elements of the various aspects described throughout this disclosure that are known or later come to be known to those of ordinary skill in the art are expressly incorporated herein by reference and are intended to be encompassed by the claims. Moreover, nothing disclosed herein is intended to be dedicated to the public regardless of whether such disclosure is explicitly recited in the claims.

Claims

A method of wireless communication, comprising:

establishing, by a user equipment, a connection with a base station on a component carrier that utilizes frequency division duplexing;

providing, to the base station, user equipment capability information including a downlink interruption time needed to complete an uplink transmit switching operation in connection with a second component carrier that utilizes time division duplexing;

transmitting, during a first period of time, data to the base station utilizing a first transmit chain on the first component carrier;

receiving, during the first period of time, data using the second component carrier;

receiving a SLIV value indicative of a start symbol value S for which the base station has scheduled a next downlink to start in relation to a beginning of the upcoming slot;

determining, based on the start value, that downlink using the first component carrier is scheduled to be inhibited for a contiguous period of time equal to or greater than a sum of a transient time and the downlink interruption time; and

receiving, during the upcoming slot, data using the first component carrier beginning at a symbol associated with the start value.
The method of claim 1, further comprising transmitting, during a second period of time coinciding at least in part with the upcoming slot, data using the second component carrier using the first transmit chain on the second component carrier and a second transmit chain on the second component carrier, wherein transmitting via the first component carrier is inhibited during the second period of time.
The method of claim 1, wherein the downlink interruption time is longer than a slot length on the first component carrier, and

wherein the SLIV value is associated with a K0 value greater than 0.
The method of claim 3, wherein the downlink interruption time is less than or equal to the sum of the slot length and S.
The method of claim 4, wherein the first component carrier corresponds to band n1 and the second component carrier corresponds to band n78.
A method of wireless communication, comprising:

establishing, by a base station, a connection with a user equipment on a component carrier that utilizes frequency division duplexing;

receiving, from the user equipment, user equipment capability information including an downlink interruption time needed to complete an uplink transmit switching operation in connection with a second component carrier that utilizes time division duplexing;

receiving, during a first period of time, data from the user equipment transmitted utilizing a first transmit chain on the first component carrier;

transmitting, to the user equipment, an indication that an uplink switching operation has been initiated for an upcoming slot associated with the first component carrier;

determining, based on the downlink interruption time and a transient time, a starting symbol at which to schedule a next downlink to the user equipment in relation to a beginning of the upcoming slot;

providing, to the user equipment, a SLIV value indicative of a start symbol value S corresponding to the symbol at which the next downlink to the user equipment is scheduled to start;

inhibiting transmission of data to the user equipment using the first component carrier from at least the beginning of the upcoming slot until the starting symbol indicated by the SLIV value; and

transmitting, during the upcoming slot, data using the first component carrier beginning at a symbol associated with the start value.
The method of claim 6, further comprising:

determining that the downlink interruption time is longer than a slot length on the first component carrier, and

in response to determining that the downlink interruption time is longer than a slot length on the first component carrier, increasing a value of K0 associated with the SLIV value sent during the first slot.
The method of claim 7, wherein the downlink interruption time is less than or equal to the sum of the slot length and S.
The method of claim 8, wherein the first component carrier corresponds to band n1 and the second component carrier corresponds to band n78.
An apparatus for wireless communication, comprising:

one or more features described in the specification and claims provided above.
A non-transitory computer-readable medium storing computer-executable code, comprising code for causing a computer to:

carry out one or more processes described in the Specification and Claims provided above.
An apparatus for wireless communication, comprising:

a processor;

a transceiver communicatively coupled to the at least one processor; and

a memory communicatively coupled to the at least one processor,

wherein the processor is configured to:

carry out one or more processes described in the Specification and Claims provided above.