WO2026001025A1

WO2026001025A1 - Methods and apparatuses for carrier switching

Info

Publication number: WO2026001025A1
Application number: PCT/CN2025/078489
Authority: WO
Inventors: Haipeng Lei
Original assignee: Lenovo Beijing Ltd
Current assignee: Lenovo Beijing Ltd
Priority date: 2025-02-21
Filing date: 2025-02-21
Publication date: 2026-01-02
Anticipated expiration: 2027-08-21

Abstract

The present disclosure relates to methods and apparatuses for carrier switching. A UE may: receive signaling indicating a carrier switching pattern, wherein the carrier switching pattern includes a first number of slots for the UE to receive a downlink transmission or transmit an uplink transmission on a first carrier and a second number of slots for the UE to receive a downlink transmission on a second carrier; and transmit, on the first carrier, HARQ-ACK feedback for the downlink transmission received by the UE on the first carrier within the first number of slots and for the downlink transmission received by the UE on the second carrier within the second number of slots, or transmit the uplink transmission on the first carrier within the first number of slots.

Description

METHODS AND APPARATUSES FOR CARRIER SWITCHING

TECHNICAL FIELD

Embodiments of the present disclosure relate generally to wireless communication technology, and more particularly to carrier switching in a wireless communication network.

BACKGROUND

A wireless communication system may include one or multiple network communication devices, such as base stations (BSs) , which may support wireless communication for one or multiple user communication devices, which may be otherwise known as user equipment (UE) , or other suitable terminology. The wireless communication system may support wireless communication with one or multiple user communication devices by utilizing resources of the wireless communication system (e.g., time resources (e.g., symbols, slots, subframes, frames, or the like) ) or frequency resources (e.g., subcarriers, carriers, or the like) . Additionally, the wireless communication system may support wireless communication across various radio access technologies including third generation (3G) radio access technology, fourth generation (4G) radio access technology, fifth generation (5G) (which is also known as new radio (NR) ) radio access technology, among other suitable radio access technologies beyond 5G (e.g., sixth generation (6G) ) .

SUMMARY

An article “a” before an element is unrestricted and understood to refer to “at least one” of those elements or “one or more” of those elements. The terms “a, ” “at least one, ” “one or more, ” and “at least one of one or more” may be interchangeable. As used herein, including in the claims, “or” as used in a list of items (e.g., a list of items prefaced by a phrase such as “at least one of” or “one or more of” or “one or both of” ) indicates an inclusive list such that, for example, a list of at least one of A, B, or C means A or B or C or AB or AC or BC or ABC (i.e., A and B and C) . Also, as used herein, the phrase “based on” shall not be construed as a reference to a closed set of conditions. For example, an example step that is described as “based on condition A” may be based on both a condition A and a condition B without departing from the scope of the present disclosure. In other words, as used herein, the phrase “based on” shall be construed in the same manner as the phrase “based at least in part on. ” Further, as used herein, including in the claims, a “set” , a “group” or a “list” may include one or more elements.

Some embodiments of the present disclosure provide a UE. The UE may include at least one memory; and at least one processor coupled with the at least one memory and configured to cause the UE to: receive signaling indicating a carrier switching pattern, wherein the carrier switching pattern includes a first number of slots for the UE to receive a downlink transmission or transmit an uplink transmission on a first carrier, a second number of slots for the UE to receive a downlink transmission on a second carrier, and a gap between the first number of slots and the second number of slots in a time domain; and transmit, on the first carrier, hybrid automatic repeat request acknowledgement (HARQ-ACK) feedback for the downlink transmission received by the UE on the first carrier within the first number of slots and for the downlink transmission received by the UE on the second carrier within the second number of slots, or transmit the uplink transmission on the first carrier within the first number of slots.

In some embodiments, the at least one processor is configured to cause the UE to: monitor a physical downlink control channel (PDCCH) on the first carrier within the first number of slots and on the second carrier within the second number of slots; or monitor a PDCCH only on the first carrier within the first number of slots.

In some embodiments, the gap includes a first gap for the UE to switch from the first carrier to the second carrier and the carrier switching pattern further includes a second gap for the UE to switch from the second carrier to the first carrier.

In some embodiments, the first gap is located after the first number of slots and before the second number of slots, and the second gap is located after or at an end of the second number of slots.

In some embodiments, the signaling indicates one or more of the following parameters for the carrier switching pattern: a period of the carrier switching pattern; a value of the first number; a value of the second number; a third number of symbols for the UE to receive a downlink transmission or transmit an uplink transmission on the first carrier, the third number of symbols being located immediately after the first number of slots; a fourth number of symbols for the UE to receive a downlink transmission on the second carrier, the fourth number of symbols being located immediately before the second number of slots; and a fifth number of symbols for the UE to receive a downlink transmission on the second carrier, the fifth number of symbols being located between the second number of slots and the second gap, or immediately before the second gap within the second number of slots.

In some embodiments, the second number of slots is located after the first number of slots, the first gap is located at a beginning of the second number of slots or at an end of the first number of slots, and the second gap is located at an end of the second number of slots.

In some embodiments, the signaling indicates one or more of the following parameters for the carrier switching pattern: a period of the carrier switching pattern; a value of the first number; a value of the second number; a number of symbols within the first gap; and a number of symbols within the second gap.

In some embodiments, the signaling indicates a bitmap for the carrier switching pattern, and each bit in the bitmap: corresponds to one slot and indicates the UE either to switch to the first carrier or the second carrier in a corresponding slot, or corresponds to one slot group and indicates the UE either to switch to the first carrier or the second carrier in a corresponding slot group.

In some embodiments, a first bit in the bitmap indicates the UE to switch to the first carrier and a second bit next to the first bit in the bitmap indicates the UE to switch to the second carrier. In some embodiments, the first gap is located at an end of a slot or slot group corresponding to the first bit or at a beginning of a slot or slot group corresponding to the second bit.

In some embodiments, a first bit in the bitmap indicates the UE to switch to the second carrier and a second bit next to the first bit in the bitmap indicates the UE to switch to the first carrier. In some embodiments, the second gap is located at an end of a slot or slot group corresponding to the first bit or at a beginning of a slot or slot group corresponding to the second bit.

In some embodiments, at least one of a number of symbols in the first gap or a number of symbols in the second gap is configured via signaling or predefined.

In some embodiments, a radio frame includes an integer number of the carrier switching pattern.

In some embodiments, downlink transmission occasions for synchronization signal blocks (SSBs) and reference signals on the first carrier are different from downlink transmission occasions for SSBs and reference signals on the second carrier.

In some embodiments, the first number of slots covers downlink transmission occasions for SSBs and reference signals on the first carrier. The second number of slots covers downlink transmission occasions for SSBs and reference signals on the second carrier.

Some embodiments of the present disclosure provide a BS. The BS may include at least one memory; and at least one processor coupled with the at least one memory and configured to cause the BS to: transmit, to a UE, signaling indicating a carrier switching pattern, wherein the carrier switching pattern includes a first number of slots for the UE to receive a downlink transmission or transmit an uplink transmission on a first carrier, a second number of slots for the UE to receive a downlink transmission on a second carrier, and a gap between the first number of slots and the second number of slots in a time domain; and receive, from the UE on the first carrier, HARQ-ACK feedback for the downlink transmission received by the UE on the first carrier within the first number of slots and for the downlink transmission received by the UE on the second carrier within the second number of slots, or receive from the UE the uplink transmission on the first carrier within the first number of slots.

In some embodiments, the at least one processor is configured to cause the BS to: transmit a PDCCH on the first carrier within the first number of slots or on the second carrier within the second number of slots; or transmit a PDCCH only on the first carrier within the first number of slots.

In some embodiments, the at least one processor is configured to cause the BS to configure at least one of a number of symbols in the first gap or a number of symbols in the second gap for the UE. In some embodiments, at least one of the number of symbols in the first gap or the number of symbols in the second gap is predefined.

In some embodiments, downlink transmission occasions for SSBs and reference signals on the first carrier are different from downlink transmission occasions for SSBs and reference signals on the second carrier.

In some embodiments, the first number of slots covers downlink transmission occasions for SSBs and reference signals on the first carrier. In some embodiments, the second number of slots covers downlink transmission occasions for SSBs and reference signals on the second carrier.

Some embodiments of the present disclosure provide a processor. The processor may include at least one controller coupled with at least one memory and configured to cause the processor to: receive signaling indicating a carrier switching pattern, wherein the carrier switching pattern includes a first number of slots for a UE to receive a downlink transmission or transmit an uplink transmission on a first carrier, a second number of slots for the UE to receive a downlink transmission on a second carrier, and a gap between the first number of slots and the second number of slots in a time domain; and transmit, on the first carrier, HARQ-ACK feedback for the downlink transmission received by the UE on the first carrier within the first number of slots and for the downlink transmission received by the UE on the second carrier within the second number of slots, or transmit the uplink transmission on the first carrier within the first number of slots.

Some embodiments of the present disclosure provide a processor. The processor may include at least one controller coupled with at least one memory and configured to cause the processor to: transmit, to a UE, signaling indicating a carrier switching pattern, wherein the carrier switching pattern includes a first number of slots for the UE to receive a downlink transmission or transmit an uplink transmission on a first carrier, a second number of slots for the UE to receive a downlink transmission on a second carrier, and a gap between the first number of slots and the second number of slots in a time domain; and receive, from the UE on the first carrier, HARQ-ACK feedback for the downlink transmission received by the UE on the first carrier within the first number of slots and for the downlink transmission received by the UE on the second carrier within the second number of slots, or receive from the UE the uplink transmission on the first carrier within the first number of slots.

Some embodiments of the present disclosure provide a method for wireless communication. The method may include: receiving signaling indicating a carrier switching pattern, wherein the carrier switching pattern includes a first number of slots for a UE to receive a downlink transmission or transmit an uplink transmission on a first carrier, a second number of slots for the UE to receive a downlink transmission on a second carrier, and a gap between the first number of slots and the second number of slots in a time domain; and transmitting, on the first carrier, HARQ-ACK feedback for the downlink transmission received by the UE on the first carrier within the first number of slots and for the downlink transmission received by the UE on the second carrier within the second number of slots, or transmitting the uplink transmission on the first carrier within the first number of slots.

Some embodiments of the present disclosure provide a method for wireless communication. The method may include: transmitting, to a UE, signaling indicating a carrier switching pattern, wherein the carrier switching pattern includes a first number of slots for the UE to receive a downlink transmission or transmit an uplink transmission on a first carrier, a second number of slots for the UE to receive a downlink transmission on a second carrier, and a gap between the first number of slots and the second number of slots in a time domain; and receiving, from the UE on the first carrier, HARQ-ACK feedback for the downlink transmission received by the UE on the first carrier within the first number of slots and for the downlink transmission received by the UE on the second carrier within the second number of slots, or receiving from the UE the uplink transmission on the first carrier within the first number of slots.

Some embodiments of the present disclosure provide an apparatus. According to some embodiments of the present disclosure, the apparatus may include: at least one non-transitory computer-readable medium having stored thereon computer-executable instructions; at least one receiving circuitry; at least one transmitting circuitry; and at least one processor coupled to the at least one non-transitory computer-readable medium, the at least one receiving circuitry and the at least one transmitting circuitry, wherein the at least one non-transitory computer-readable medium and the computer executable instructions may be configured to, with the at least one processor, cause the apparatus to perform a method according to some embodiments of the present disclosure.

BRIEF DESCRIPTION OF THE DRAWINGS

In order to describe the manner in which the advantages and features of the disclosure can be obtained, a description of the disclosure is rendered by reference to specific embodiments thereof, which are illustrated in the appended drawings. These drawings depict only exemplary embodiments of the disclosure and are not therefore to be considered limiting of its scope.

FIG. 1 illustrates a schematic diagram of a wireless communication system in accordance with some embodiments of the present disclosure;

FIG. 2 illustrates an exemplary band combination in accordance with some embodiments of the present disclosure;

FIG. 3A-4D illustrate exemplary carrier switching patterns in accordance with some embodiments of the present disclosure;

FIGs. 5 and 6 illustrate flowcharts of wireless communication methods in accordance with some embodiments of the present disclosure;

FIG. 7 illustrates an example of a UE in accordance with some embodiments of the present disclosure;

FIG. 8 illustrates an example of a processor in accordance with some embodiments of the present disclosure; and

FIG. 9 illustrates an example of network equipment (NE) in accordance with some embodiments of the present disclosure.

DETAILED DESCRIPTION

The detailed description of the appended drawings is intended as a description of the preferred embodiments of the present disclosure and is not intended to represent the only form in which the present disclosure may be practiced. It should be understood that the same or equivalent functions may be accomplished by different embodiments that are intended to be encompassed within the spirit and scope of the present disclosure.

Reference will now be made in detail to some embodiments of the present disclosure, examples of which are illustrated in the accompanying drawings. To facilitate understanding, embodiments are provided under a specific network architecture (s) and new service scenarios, such as the 3rd generation partnership project (3GPP) 5G NR or 6G, 3GPP LTE, and so on. It is contemplated that along with the development of network architectures and new service scenarios, all embodiments in the present disclosure are also applicable to similar technical problems; and moreover, the terminologies recited in the present disclosure may change, which should not affect the principles of the present disclosure.

A low-band spectrum is essential to communication networks due to its good coverage and penetration capabilities. The limited availability of a low-band spectrum can lead to congestion, resulting in poor data speeds and a poor customer experience.

The present disclosure provides solutions for implementing low-low carrier aggregation (CA) to improve low-band capacity. However, low-low CA faces several challenges. For example, large fractional bandwidths in a low-band spectrum can add complexity to smartphone design. For example, additional components to support low-low CA can add cost, RF architecture complexity and form factor volume. Solutions for aggregating a low-band spectrum and switching between aggregated bands are provided to address the above issues.

FIG. 1 illustrates a schematic diagram of wireless communication system 100 in accordance with some embodiments of the present disclosure.

The wireless communication system 100 may include one or more NEs 102 (e.g., one or more BSs) , one or more UEs 104, and a core network (CN) 106. The wireless communication system 100 may support various radio access technologies. In some implementations, the wireless communication system 100 may be a 4G network, such as an LTE network or an LTE-Advanced (LTE-A) network. In some other implementations, the wireless communication system 100 may be an NR network, such as a 5G network, a 5G-Advanced (5G-A) network, or a 5G ultra-wideband (5G-UWB) network. In other implementations, the wireless communication system 100 may be a combination of a 4G network and a 5G network, or other suitable radio access technology including Institute of Electrical and Electronics Engineers (IEEE) 802.11 (Wi-Fi) , IEEE 802.16 (WiMAX) , and IEEE 802.20. The wireless communication system 100 may support radio access technologies beyond 5G, for example, 6G. Additionally, the wireless communication system 100 may support technologies, such as time division multiple access (TDMA) , frequency division multiple access (FDMA) , or code division multiple access (CDMA) , etc.

The one or more NEs 102 may be dispersed throughout a geographic region to form the wireless communication system 100. One or more of the NEs 102 described herein may be or include or may be referred to as a network node, a base station, a network element, a network function, a network entity, a radio access network (RAN) , a NodeB, an eNodeB (eNB) , a next-generation NodeB (gNB) , or other suitable terminology. An NE 102 and a UE 104 may communicate via a communication link, which may be a wireless or wired connection. For example, an NE 102 and a UE 104 may perform wireless communication (e.g., receive signaling, transmit signaling) over a Uu interface.

An NE 102 may provide a geographic coverage area for which the NE 102 may support services for one or more UEs 104 within the geographic coverage area. For example, an NE 102 and a UE 104 may support wireless communication of signals related to services (e.g., voice, video, packet data, messaging, broadcast, etc. ) according to one or multiple radio access technologies. In some implementations, an NE 102 may be moveable, for example, a satellite associated with a non-terrestrial network (NTN) . In some implementations, different geographic coverage areas 112 associated with the same or different radio access technologies may overlap, but the different geographic coverage areas may be associated with a different NE 102.

The one or more UEs 104 may be dispersed throughout a geographic region of the wireless communication system 100. A UE 104 may include or may be referred to as a remote unit, a mobile device, a wireless device, a remote device, a subscriber device, a transmitter device, a receiver device, or some other suitable terminology. In some implementations, the UE 104 may be referred to as a unit, a station, a terminal, or a client, among other examples. Additionally, or alternatively, the UE 104 may be referred to as an Internet-of-Things (IoT) device, an Internet-of-Everything (IoE) device, or machine-type communication (MTC) device, among other examples.

A UE 104 may be able to support wireless communication directly with other UEs 104 over a communication link. For example, a UE 104 may support wireless communication directly with another UE 104 over a device-to-device (D2D) communication link. In some implementations, such as vehicle-to-vehicle (V2V) deployments, vehicle-to-everything (V2X) deployments, or cellular-V2X deployments, the communication link 114 may be referred to as a sidelink. For example, a UE 104 may support wireless communication directly with another UE 104 over a PC5 interface.

An NE 102 may support communication with the CN 106, or with another NE 102, or both. For example, an NE 102 may interface with another NE 102 or the CN 106 through one or more backhaul links (e.g., S1, N2, N3 or another network interface) . In some implementations, the NE 102 may communicate with each other directly. In some other implementations, the NE 102 may communicate with each other or indirectly (e.g., via the CN 106) . In some implementations, one or more NEs 102 may include subcomponents, such as an access network entity, which may be an example of an access node controller (ANC) . An ANC may communicate with the one or more UEs 104 through one or more other access network transmission entities, which may be referred to as radio heads, smart radio heads, or transmission-reception points (TRPs) .

The CN 106 may support user authentication, access authorization, tracking, connectivity, and other access, routing, or mobility functions. The CN 106 may be an evolved packet core (EPC) , or a 5G core (5GC) , which may include a control plane entity that manages access and mobility (e.g., a mobility management entity (MME) , an access and mobility management (AMF) ) functions and a user plane entity that routes packets or interconnects to external networks (e.g., a serving gateway (S-GW) , a Packet Data Network (PDN) gateway (P-GW) , or a user plane function (UPF) ) . In some implementations, the control plane entity may manage non-access stratum (NAS) functions, such as mobility, authentication, and bearer management (e.g., data bearers, signal bearers, etc. ) for the one or more UEs 104 served by the one or more NEs 102 associated with the CN 106.

The CN 106 may communicate with a packet data network over one or more backhaul links (e.g., via an S1, N2, N3, or another network interface) . The packet data network may include an application server. In some implementations, one or more UEs 104 may communicate with the application server. A UE 104 may establish a session (e.g., a protocol data unit (PDU) session, or the like) with the CN 106 via an NE 102. The CN 106 may route traffic (e.g., control information, data, and the like) between the UE 104 and the application server using the established session (e.g., the established PDU session) . The PDU session may be an example of a logical connection between the UE 104 and the CN 106 (e.g., one or more network functions of the CN 106) .

In the wireless communication system 100, the NEs 102 and the UEs 104 may use resources of the wireless communication system 100 (e.g., time resources (e.g., symbols, slots, subframes, frames, or the like) or frequency resources (e.g., subcarriers, carriers) ) to perform various operations (e.g., wireless communication) . In some implementations, the NEs 102 and the UEs 104 may support different resource structures. For example, the NEs 102 and the UEs 104 may support different frame structures. In some implementations, such as in 4G, the NEs 102 and the UEs 104 may support a single frame structure. In some other implementations, such as in 5G and among other suitable radio access technologies, the NEs 102 and the UEs 104 may support various frame structures (i.e., multiple frame structures) . The NEs 102 and the UEs 104 may support various frame structures based on one or more numerologies.

In some embodiments, the NEs 102 may include one or more relay nodes, integrated access and backhaul (IAB) nodes or wireless access backhaul (WAB) nodes which can provide wireless access services for UEs 104. A relay node (or an IAB node or a WAB node) can directly connect to a BS or hop through one or more relay nodes (or one or more IAB or WAB nodes) before reaching the BS.

One or more numerologies may be supported in the wireless communication system 100, and a numerology may include subcarrier spacing and a cyclic prefix. A first numerology (e.g., μ=0) may be associated with a first subcarrier spacing (e.g., 15 kHz) and a normal cyclic prefix. In some implementations, the first numerology (e.g., μ=0) associated with the first subcarrier spacing (e.g., 15 kHz) may utilize one slot per subframe. A second numerology (e.g., μ =1) may be associated with a second subcarrier spacing (e.g., 30 kHz) and a normal cyclic prefix. A third numerology (e.g., μ=2) may be associated with a third subcarrier spacing (e.g., 60 kHz) and a normal cyclic prefix or an extended cyclic prefix. A fourth numerology (e.g., μ=3) may be associated with a fourth subcarrier spacing (e.g., 120 kHz) and a normal cyclic prefix. A fifth numerology (e.g., μ=4) may be associated with a fifth subcarrier spacing (e.g., 240 kHz) and a normal cyclic prefix. A sixth numerology (e.g., μ =5) may be associated with a sixth subcarrier spacing (e.g., 480 kHz) and a normal cyclic prefix. A seventh numerology (e.g., μ=6) may be associated with a seventh subcarrier spacing (e.g., 960 kHz) and a normal cyclic prefix. For ambient IoT communication, additional numerologies (e.g., μ=-1 or μ =-2) may be introduced corresponding to 7.5 kHz or 3.75 kHz, respectively.

A time interval of a resource (e.g., a communication resource) may be organized according to frames (also referred to as radio frames) . Each frame may have a duration, for example, a 10 millisecond (ms) duration. In some implementations, each frame may include multiple subframes. For example, each frame may include 10 subframes, and each subframe may have a duration, for example, a 1 ms duration. In some implementations, each frame may have the same duration. In some implementations, each subframe of a frame may have the same duration.

Additionally or alternatively, a time interval of a resource (e.g., a communication resource) may be organized according to slots. For example, a subframe may include a number (e.g., quantity) of slots. The number of slots in each subframe may also depend on the one or more numerologies supported in the wireless communication system 100. For instance, the first, second, third, fourth, and fifth numerologies (i.e., μ=0, μ=1, μ=2, μ=3, μ=4) associated with respective subcarrier spacings (SCSs) of 15 kHz, 30 kHz, 60 kHz, 120 kHz, and 240 kHz may utilize a single slot per subframe, two slots per subframe, four slots per subframe, eight slots per subframe, and 16 slots per subframe, respectively. Each slot may include a number (e.g., quantity) of symbols (e.g., orthogonal frequency-division multiplexing (OFDM) symbols) . In some implementations, the number (e.g., quantity) of slots for a subframe may depend on a numerology. For a normal cyclic prefix, a slot may include 14 symbols. For an extended cyclic prefix (e.g., applicable for 60 kHz subcarrier spacing) , a slot may include 12 symbols. The relationship between the number of symbols per slot, the number of slots per subframe, and the number of slots per frame for a normal cyclic prefix and an extended cyclic prefix may depend on a numerology. It should be understood that reference to a first numerology (e.g., μ=0) associated with a first subcarrier spacing (e.g., 15 kHz) may be used interchangeably between subframes and slots.

In the wireless communication system 100, an electromagnetic (EM) spectrum may be split, based on frequency or wavelength, into various classes, frequency bands, frequency channels, etc. By way of example, the wireless communication system 100 may support one or multiple operating frequency bands, such as frequency range designations FR1 (410 MHz –7.125 GHz) , FR2 (24.25 GHz –52.6 GHz) , FR3 (7.125 GHz –24.25 GHz) , FR4 (52.6 GHz –114.25 GHz) , FR4a or FR4-1 (52.6 GHz –71 GHz) , and FR5 (114.25 GHz –300 GHz) . In some implementations, the NEs 102 and the UEs 104 may perform wireless communication over one or more of the operating frequency bands. In some implementations, FR1 may be used by the NEs 102 and the UEs 104, among other equipment or devices for cellular communication traffic (e.g., control information, data) . In some implementations, FR2 may be used by the NEs 102 and the UEs 104, among other equipment or devices for short-range, high data rate capabilities.

FR1 may be associated with one or multiple numerologies (e.g., at least three numerologies) . For example, FR1 may be associated with a first numerology (e.g., μ =0) , which includes 15 kHz subcarrier spacing; a second numerology (e.g., μ =1) , which includes 30 kHz subcarrier spacing; and a third numerology (e.g., μ=2) , which includes 60 kHz subcarrier spacing. FR2 may be associated with one or multiple numerologies (e.g., at least two numerologies) . For example, FR2 may be associated with a third numerology (e.g., μ=2) , which includes 60 kHz subcarrier spacing; and a fourth numerology (e.g., μ=3) , which includes 120 kHz subcarrier spacing.

A UE 104 may include computing devices, such as desktop computers, laptop computers, personal digital assistants (PDAs) , tablet computers, smart televisions (e.g., televisions connected to the Internet) , set-top boxes, game consoles, security systems (including security cameras) , vehicle on-board computers, network devices (e.g., routers, switches, and modems) , or the like. According to some embodiments of the present disclosure, a UE 104 may include a portable wireless communication device, a smart phone, a cellular telephone, a flip phone, a device having a subscriber identity module, a personal computer, a selective call receiver, or any other device that is capable of sending and receiving communication signals on a wireless network. In some embodiments of the present disclosure, a UE 104 includes wearable devices, such as smart watches, fitness bands, optical head-mounted displays, or the like. Moreover, a UE 104 may be referred to as a subscriber unit, a mobile, a mobile station, a user, a terminal, a mobile terminal, a wireless terminal, a fixed terminal, a subscriber station, a user terminal, or a device, or described using other terminology used in the art. A UE 104 may communicate with an NE 102 (e.g., a BS) via uplink (UL) communication signals. An NE 102 may communicate with a UE 104 via downlink (DL) communication signals.

In some embodiments of the present disclosure, an NE 102 and a UE 104 may communicate over licensed spectrums, whereas in some other embodiments, an NE 102 and a UE 104 may communicate over unlicensed spectrums. The present disclosure is not intended to be limited to the implementation of any particular wireless communication system architecture or protocol. Persons skilled in the art should understand that as technology develops and advances, the terminologies described in the present disclosure may change, but should not affect or limit the principles and spirit of the present disclosure.

A low-band spectrum is essential to communication networks due to its good coverage and penetration capabilities. For example, as a UE moves between different sites, such as urban and rural areas, it increasingly relies on low-band coverage. This spectrum carries significant traffic volumes in both urban and rural markets. However, the limited availability of a low-band spectrum can lead to congestion, resulting in poor data speeds and a poor customer experience, especially in areas where low-band coverage is dominant.

Embodiments of the present disclosure provide solutions for implementing low-low CA to enhance low-band capacity. This approach faces several challenges. For example, large fractional bandwidths in a low-band spectrum add complexity to smartphone design, particularly from an antenna design perspective. If an original equipment manufacturer (OEM) chooses to implement a single antenna to aggregate these bands, tuning solutions may be required to optimize performance. Optimizing for both bands simultaneously can be challenging due to their separation in frequency. Another potential design choice is to implement additional antenna elements to support these combinations. However, this approach may introduce cost and RF architecture complexity, including the need for additional components and increased form factor volume. These practical implementation challenges may pose a barrier to the widespread adoption of low-low CA solutions across a broad range of devices.

For example, referring to FIG. 2, band 221 and band 223 are aggregated for a UE and each corresponds to a cell. In some embodiments, band 221 and band 223 may both be low frequency bands. For example, band 221 may be band n5 or band n12 and band 223 may be band n29. In some embodiments, band 221 is a frequency division duplexing (FDD) band, which can be used for DL transmissions and UL transmissions. Band 223 is a DL only band (i.e., a supplementary DL band) , which can be used only for DL transmission. Band 223 cannot be paired with the UL of band 221 due to the close proximity of band 223 to the UL of band 221 in the frequency domain, making it impossible to separate the two bands using filters. In addition, UE vendors choose a single antenna to aggregate band 223 and band 221, which implies that both band 221 and band 223 cannot be activated simultaneously. In this sense, the UE has to switch back and forth, between band 221 and band 223, with consideration of switching delay for each carrier switching.

To solve the above issues, embodiments of the present disclosure provide solutions for aggregating a low-band spectrum and switching between aggregated bands. More details on the embodiments of the present disclosure will be illustrated in the following text in combination with the appended drawings.

In some embodiments of the present disclosure, a UE may support the following:
-the UE supports switching: when the secondary cell (SCell) operation is
triggered, the UE needs to switch to the SCell, and during the operation period there is no simultaneous transmission or reception between the Primary Cell (PCell) and the SCell; and
-the UE switches back to the PCell after the SCell operation is finished.

In some embodiments of the present disclosure, a carrier switching pattern is introduced for a UE to tune its RF between carriers (e.g., two or more low frequency bands) . For example, for a UE configured with low band CA, a carrier switching pattern may be configured for the UE by a BS via signaling. The carrier switching pattern may indicate the UE to tune its RF between two carriers (denoted as carrier #1 and carrier #2) , each of which may correspond to a cell. For example, carrier #1 may be configured as cell #1 and carrier #2 may be configured as cell #2.

In some embodiments, there are two cases for the UE to operate on such a band combination:
-Case 1: When the UE switches to carrier #1, the UE receives DL transmissions
only on cell #1 and transmits UL transmissions only on cell #1. The UE does not monitor any DL transmissions on cell #2 or transmit anything on cell #2.
-Case 2: When the UE switches to carrier #2, the UE receives DL transmissions
only on cell #2. The UE does not monitor any DL transmissions on cell #1 or transmit anything on cell #1.

For example, the UE can perform both DL transmissions and UL transmissions on carrier #1 and can only perform DL transmissions on carrier #2. For example, carrier #1 is an FDD carrier with paired UL and DL bands while carrier #2 is a DL-only carrier and cell #2 is a DL-only cell. In some embodiments, cell #1 may be configured as the PCell and cell #2 may be configured as an SCell.

In some embodiments, considering the above operation cases, the carrier switching pattern may include a plurality of time domain resources (e.g., a number of slots denoted as slot set #1) for the UE to perform downlink transmission or uplink transmission on carrier #1 and a plurality of time domain resources (e.g., a number of slots denoted as slot set #2) for the UE to perform downlink transmission on carrier #2. In some embodiments, slot set #1 and slot set #2 do not overlap in the time domain. In some embodiments, considering the switching delay, the carrier switching pattern may include a gap for the UE to switch from carrier #1 to carrier #2 and a gap for the UE to switch from carrier #2 to carrier #1.

In some embodiments, the UE may monitor a PDCCH (e.g., downlink control information (DCI) ) on carrier #1 (cell #1) within slot set #1 and carrier #2 (cell #2) within slot set #2. In some embodiments, the UE may monitor a PDCCH (e.g., DCI) only on carrier #1 (cell #1) within slot set #1, and does not monitor a PDCCH on carrier #2 (cell #2) . PDCCHs on the DL band of carrier #1 (cell #1) or the DL band of carrier #2 (cell #2) can schedule physical uplink shared channel (PUSCH) transmissions on the UL band of carrier #1 (cell #1) . In some embodiments, HARQ-ACK feedback for DL transmissions (e.g., physical downlink shared channel (PDSCHs) ) on carrier #1 and carrier #2 is transmitted on the UL band of carrier #1 (cell #1) .

In some embodiments, the carrier switching pattern may follow one or more design principles. For example, DL transmission occasions for SSBs and reference signals on cell #1 should be different from those on cell #2 to avoid losing synchronization on the two cells. For example, due to the inevitable switching delay for each carrier switching (e.g., about tens of microseconds) , the carrier switching pattern should be designed to avoid frequent switching as much as possible. However, carrier switching may need to occur frequently enough because, for example, the UE may need to switch to cell #1 for certain operations, such as transmitting HARQ-ACK feedback for the PDSCHs received on cell #1.

Based on the above considerations and design principles, the following embodiments provide some examples of carrier switching patterns. Note that persons skilled in the art can conceive of alternatives, modifications or variations on the exemplary patterns, which are also covered by the present disclosure.

FIG. 3A-3C illustrate exemplary carrier switching patterns in accordance with some embodiments of the present disclosure. The illustrated carrier switching patterns may be periodic and can be configured by RRC signaling or a system information block (SIB) .

Referring to FIG. 3A, carrier switching pattern 300A may include a number of slots for carrier 311, a number of slots for carrier 313, gap 315 for switching from carrier 311 to carrier 313 and gap 317 for switching from carrier 313 to carrier 311. In some embodiments, gap 315 is located after the slots for carrier 311 and before the slots for carrier 313, and gap 317 is located after or at the end of the slots for carrier 313. In some embodiments, one or more of gap 315 and gap 317 may not exist.

According to carrier switching pattern 300A, transmission and/or reception on one of carrier 311 and carrier 313 and transmission on the other of carrier 311 and carrier 313 cannot happen simultaneously. In some embodiments, carrier 311 may be carrier #1 and carrier 313 may be carrier #2. In some embodiments, carrier 311 may be carrier #2 and carrier 313 may be carrier #1.

In some embodiments, carrier switching pattern 300A may be defined by one or more of the following parameters, which may be configured for the UE by the BS via signaling or predefined (e.g., in a standard) :
-the carrier switching pattern period (e.g., P slots) ;
-the number of slots (X₁ slots) dedicated for carrier 311 and located at the
beginning of the carrier switching pattern;
-the number of slots (X₂ slots) dedicated for carrier 313 and located at the end
of the carrier switching pattern;
-the number of symbols (Y₁ symbols) dedicated for carrier 311 and located at
the beginning of the (X₁+1) ^th slot of the carrier switching pattern;
-the number of symbols (Y₂ symbols) dedicated for carrier 313 and located at
the end of the (X₁+1) ^th slot of the carrier switching pattern; and
-the number of symbols (Y₃ symbols) dedicated for carrier 313 and located in
the last slot of the carrier switching pattern.

It is assumed that a slot may include 14 symbols in the context of the present disclosure. In some embodiments, Y₁ can be configured or predefined within the range of [0, 13] to support nothing for carrier 311 or almost full slot utilization for carrier 311. In some embodiments, Y₂ can be configured or predefined within the range of [0, 13] to support nothing for carrier 313 or almost full slot utilization for carrier 313. In some embodiments, Y₁ + Y₂ may smaller than or equal to 13, leaving at least one symbol for gap 315. In some embodiments, Y₃ can be configured or predefined within the range of [0, 13] , leaving at least one symbol for gap 317.

As shown in FIG. 3A, partial slots for carrier 311 or carrier 313 occur in carrier switching pattern 300A due to carrier switching delay between the two carriers. Carrier switching from carrier 311 to carrier 313 can happen in the (X₁+1) ^th slot of the P slots, wherein Y₁ symbols at the beginning of the (X₁+1) ^th slot of the P slots are dedicated for carrier 311 while Y₂ symbols at the end of the (X₁+1) ^th slot of the P slots are dedicated for carrier 313. Hence, in the (X₁+1) ^th slot of the P slots, 14-Y₁-Y₂ symbols are reserved as the switching gap (e.g., gap 315) . Carrier switching from carrier 313 to carrier 311 can happen in the last slot of the P slots, wherein Y₃ symbols in the last slot of the P slots are dedicated for carrier 313. Hence, in the last slot of the P slots, 14-Y₃ symbols are reserved as the switching gap (e.g., gap 317) .

In some embodiments, the X₁ slots dedicated for carrier 311 are always located at the beginning of the P slots of the carrier switching pattern. The X₁ slots dedicated for carrier 311 may cover the transmission occasions for SSBs and reference signals on the carrier. In some embodiments, the X₂ slots dedicated for carrier 313 are always located at the end of the P slots of the carrier switching pattern. The X₂ slots dedicated for carrier 313 may cover the transmission occasions for SSBs and reference signals on the carrier.

In some embodiments, as the value of P can be determined based on the values of X₁ and X₂, only two parameters of {X₁, X₂, P} may be configured or predefined for carrier switching pattern 300A. In some embodiments, instead of configuring or predefining the X₂ slots which include X₂-1 full slots and one partial slot (i.e., the last slot in the P slots including gap 317) , the X₂-1 full slots (e.g., the value of X₂-1) may be configured or predefined. It can be determined that the first Y₃ symbols of the slot after the X₂-1 full slots are dedicated for carrier 313 and that the remaining symbols in this slot are reserved for gap 317. That is, gap 317 is located after the X₂-1 full slots for carrier 313.

In some embodiments, instead of configuring or predefining the value of X₁, the value of X₁+1 may be configured or predefined to denote the X₁ full slots for carrier 311 and the (X₁+1) ^th slot in FIG. 3A. In some embodiments, instead of configuring or predefining the value of X₂, the value of X₂+1 may be configured or predefined to denote the X₂ slots for carrier 313 and gap 317 and the (X₁+1) ^th slot in FIG. 3A.

In some embodiments, a radio frame (e.g., one radio frame such as 10ms) may include an integer number of carrier switching pattern 300A. For example, one radio frame can be evenly divided by the duration of P slots. Assuming that the SCS configuration for both carrier 311 and carrier 313 is μ, then one radio frame includes 10×2^μ slots and 10×2^μ mod P should be equal to 0. The duration of P slots can be determined based on the SCS, for example, the carrier switching pattern has a duration of P×2^﹣μ ms.

In other embodiments, a carrier switching pattern may include an integer number of radio frames. For example, the duration of P slots can be evenly divided by one radio frame. Assuming that the SCS configuration for both carrier 311 and carrier 313 is μ^a, then one radio frame includes slots and P mod should be equal to 0. For example, in the case of 15 kHz SCS, one radio frame includes 10 slots, and P may be set to 20 or 40 in order to cover 2 or 4 radio frames within one carrier switching pattern.

The SCS configurations for carrier 311 and carrier 313 can be the same or different.

Referring to FIG. 3B, carrier switching pattern 300B may include a number of slots for carrier 321, a number of slots for carrier 323, gap 325 for switching from carrier 321 to carrier 323 and gap 327 for switching from carrier 323 to carrier 321. In some embodiments, the slots for carrier 323 are located after the slots for carrier 321, gap 325 is located at the beginning of the slots for carrier 323, and gap 327 is located at the end of the slots for carrier 323. In some embodiments, one or more of gap 325 and gap 327 may not exist.

According to carrier switching pattern 300B, transmission and/or reception on one of carrier 321 and carrier 323 and transmission on the other of carrier 321 and carrier 323 cannot happen simultaneously. In some embodiments, carrier 321 may be carrier #1 and carrier 323 may be carrier #2. In some embodiments, carrier 321 may be carrier #2 and carrier 323 may be carrier #1.

In some embodiments, carrier switching pattern 300B may be defined by one or more of the following parameters, which may be configured for the UE by the BS via signaling or predefined (e.g., in a standard) :
-the carrier switching pattern period (e.g., P' slots) ;
-the number of slots (X₁' slots) dedicated for carrier 321 and located at the
beginning of the carrier switching pattern;
-the number of slots (X₂' slots) dedicated for carrier 323 and located at the end
of the carrier switching pattern;
-the number of symbols (Z₁ symbols) reserved as a switching gap (e.g., gap 325)
from carrier 321 to carrier 323 and located at the beginning of the (X₁' +1) ^th slot of the carrier switching pattern; and
-the number of symbols (Z₂ symbols) reserved as a switching gap (e.g., gap 327)
from carrier 323 to carrier 321 and located in the last slot of the carrier switching pattern.

It is assumed that a slot may include 14 symbols in the context of the present disclosure. In some embodiments, Z₁ can be configured or predefined within the range of [0, 14] to support variable switching gaps between the two carriers. In some embodiments, Z₁ can be predefined to a fixed value (e.g., 1) to reduce RRC signaling overhead. In some embodiments, Z₂ can be configured or predefined within the range of [0, 14] to support variable switching gaps between the two carriers. In some embodiments, Z₂ can be predefined to a fixed value (e.g., 1) to reduce RRC signaling overhead.

As shown in FIG. 3B, partial slots for carrier 321 or carrier 323 occur in carrier switching pattern 300B due to carrier switching delay between the two carriers. Carrier switching from carrier 321 to carrier 323 can happen in the (X₁' +1) ^th slot of the P' slots, wherein Z₁ symbols at the beginning of the (X₁' +1) ^th slot of the P' slots are reserved for carrier switching from carrier 321 to carrier 323 while 14-Z₁ symbols at the end of the (X₁' +1) ^th slot of the P' slots are dedicated for carrier 323. Carrier switching from carrier 323 to carrier 321 can happen in the last slot of the P' slots, wherein Z₂ symbols in the last slot of the P' slots are reserved for carrier switching from carrier 323 to carrier 321. Hence, in the last slot of the P' slots, 14-Z₂ symbols are dedicated for carrier 323.

In some embodiments, the X₁' slots dedicated for carrier 321 are always located at the beginning of the P' slots of the carrier switching pattern. The X₁' slots dedicated for carrier 321 may cover the transmission occasions for SSBs and reference signals on the carrier. In some embodiments, the X₂' slots dedicated for carrier 323 are always located at the end of the P' slots of the carrier switching pattern. The X₂' slots dedicated for carrier 323 may cover the transmission occasions for SSBs and reference signals on the carrier.

In some embodiments, as the value of P' can be determined based on the values of X₁' and X₂', only two parameters of {X₁', X₂', P' } may be configured or predefined for carrier switching pattern 300B. In some embodiments, instead of configuring or predefining the value of X₁' , the value of X₁' +1 may be configured or predefined to denote the X₁' full slots for carrier 321 and the (X₁' +1) ^th slot in FIG. 3B. In some embodiments, instead of configuring or predefining the value of X₂' , the value of X₂' -1 may be configured or predefined to denote the X₂' -1 slots for carrier 323 and exclude one of the two partial slots, i.e., the (X₁' +1) ^th slot and the last slot in FIG. 3B. In some embodiments, instead of configuring or predefining the value of X₂' , the value of X₂' -2 may be configured or predefined to denote the X₂' -2 slots for carrier 323 and exclude the two partial slots, i.e., the (X₁' +1) ^th slot and the last slot in FIG. 3B.

In some embodiments, a radio frame (e.g., one radio frame such as 10ms) may include an integer number of carrier switching pattern 300B. For example, one radio frame can be evenly divided by the duration of P' slots. Assuming that the SCS configuration for both carrier 321 and carrier 323 is μ′, then one radio frame includes 10×2^μ′slots and 10×2^μ′mod P' should be equal to 0. The duration of P' slots can be determined based on the SCS, for example, the carrier switching pattern has a duration of P′×2^﹣μ′ms.

In other embodiments, a carrier switching pattern may include an integer number of radio frames. For example, the duration of P' slots can be evenly divided by one radio frame. Assuming that the SCS configuration for both carrier 321 and carrier 323 is μ^b, then one radio frame includes slots and P' mod should be equal to 0. For example, in the case of 15 kHz SCS, one radio frame includes 10 slots, and P' may be set to 20 or 40 in order to cover 2 or 4 radio frames within one carrier switching pattern.

The SCS configurations for carrier 321 and carrier 323 can be the same or different.

Referring to FIG. 3C, carrier switching pattern 300C may include a number of slots for carrier 331, a number of slots for carrier 333, gap 335 for switching from carrier 331 to carrier 333 and gap 337 for switching from carrier 333 to carrier 331. In some embodiments, the slots for carrier 333 are located after the slots for carrier 331, gap 335 is located at the end of the slots for carrier 331, and gap 337 is located at the end of the slots for carrier 333. In some embodiments, one or more of gap 335 and gap 337 may not exist.

According to carrier switching pattern 300B, transmission and/or reception on one of carrier 331 and carrier 333 and transmission on the other of carrier 331 and carrier 333 cannot happen simultaneously. In some embodiments, carrier 331 may be carrier #1 and carrier 333 may be carrier #2. In some embodiments, carrier 331 may be carrier #2 and carrier 333 may be carrier #1.

In some embodiments, carrier switching pattern 300C may be defined by one or more of the following parameters, which may be configured for the UE by the BS via signaling or predefined (e.g., in a standard) :
-the carrier switching pattern period (e.g., P” slots) ;
-the number of slots (X₁” slots) dedicated for carrier 331 and located at the
beginning of the carrier switching pattern;
-the number of slots (X₂” slots) dedicated for carrier 333 and located at the end
of the carrier switching pattern;
-the number of symbols (Z₁' symbols) reserved as a switching gap (e.g., gap
335) from carrier 331 to carrier 333 and located at the end of the (X₁” ) ^th slot of the carrier switching pattern; and
-the number of symbols (Z₂' symbols) reserved as a switching gap (e.g., gap
337) from carrier 333 to carrier 331 and located in the last slot of the carrier switching pattern.

It is assumed that a slot may include 14 symbols in the context of the present disclosure. In some embodiments, Z₁' can be configured or predefined within the range of [0, 14] to support variable switching gaps between the two carriers. In some embodiments, Z₁' can be predefined to a fixed value (e.g., 1) to reduce RRC signaling overhead. In some embodiments, Z₂' can be configured or predefined within the range of [0, 14] to support variable switching gaps between the two carriers. In some embodiments, Z₂' can be predefined to a fixed value (e.g., 1) to reduce RRC signaling overhead.

As shown in FIG. 3C, partial slots for carrier 331 or carrier 333 occur in carrier switching pattern 300C due to carrier switching delay between the two carriers. Carrier switching from carrier 331 to carrier 333 can happen in the (X₁” ) ^th slot of the P” slots, wherein Z₁' symbols at the end of the (X₁” ) ^th slot of the P” slots are reserved for carrier switching from carrier 331 to carrier 333 while 14-Z₁' symbols at the beginning of the (X₁” ) ^th slot of the P” slots are dedicated for carrier 331. Carrier switching from carrier 333 to carrier 331 can happen in the last slot of the P” slots, wherein Z₂' symbols in the last slot of the P” slots are reserved for carrier switching from carrier 333 to carrier 331. Hence, in the last slot of the P” slots, 14-Z₂' symbols are dedicated for carrier 333.

In some embodiments, the X₁” slots dedicated for carrier 331 are always located at the beginning of the P” slots of the carrier switching pattern. The X₁” slots dedicated for carrier 331 may cover the transmission occasions for SSBs and reference signals on the carrier. In some embodiments, the X₂” slots dedicated for carrier 333 are always located at the end of the P” slots of the carrier switching pattern. The X₂” slots dedicated for carrier 333 may cover the transmission occasions for SSBs and reference signals on the carrier.

In some embodiments, as the value of P” can be determined based on the values of X₁” and X₂” , only two parameters of {X₁” , X₂” , P” } may be configured or predefined for carrier switching pattern 300C. In some embodiments, instead of configuring or predefining the value of X₁” , the value of X₁” -1 may be configured or predefined to denote the X₁” -1 full slots for carrier 331 and exclude the partial slot, i.e., the (X₁” ) ^th slot in FIG. 3C. In some embodiments, instead of configuring or predefining the value of X₂” , the value of X₂” -1 may be configured or predefined to denote the X₂” -1 full slots for carrier 333 and exclude the partial slot, i.e., the last slot in FIG. 3C. In some embodiments, instead of configuring or predefining the value of X₂” , the value of X₂” +1 may be configured or predefined to denote the X₂” -1 full slots for carrier 333 and the two partial slots, i.e., the (X₁” ) ^th slot and the last slot in FIG. 3C.

In some embodiments, a radio frame (e.g., one radio frame such as 10ms) may include an integer number of carrier switching pattern 300C. For example, one radio frame can be evenly divided by the duration of P” slots. Assuming that the SCS configuration for both carrier 331 and carrier 333 is μ″, then one radio frame includes 10×2^μ″slots and 10×2^μ″mod P” should be equal to 0. The duration of P” slots can be determined based on the SCS, for example, the carrier switching pattern has a duration of P′×2^﹣μ″ms.

In other embodiments, a carrier switching pattern may include an integer number of radio frames. For example, the duration of P” slots can be evenly divided by one radio frame. Assuming that the SCS configuration for both carrier 331 and carrier 333 is μ^c, then one radio frame includesslots and P” modshould be equal to 0. For example, in the case of 15 kHz SCS, one radio frame includes 10 slots, and P” may be set to 20 or 40 in order to cover 2 or 4 radio frames within one carrier switching pattern.

The SCS configurations for carrier 331 and carrier 333 can be the same or different.

From the perspective of a BS, the BS can transmit downlink signals or channels within the switching gap (e.g., gap 315 or 317 in FIG. 3A, gap 325 or 327 in FIG. 3B or gap 335 or 337 in FIG. 3C) and repeat the downlink signals or channels from the first symbol after the switching. These downlink signals or channels within the switching gap can be used as automatic gain control (AGC) symbols for the UE to adjust the receive (Rx) chain. From the perspective of a UE, the UE does not expect to receive downlink signals or channels or transmit uplink signals or channels within the switching gap.

The carrier switching pattern (e.g., carrier switching pattern 300A in FIG. 3A, carrier switching pattern 300B in FIG. 3B or carrier switching pattern 300C in FIG. 3C) may be started from one specific (e.g., the first) slot of a radio frame and repeated until another specific (e.g., the last) slot of the radio frame. Such repetition may be continued in the subsequent radio frames.

In some embodiments of the present disclosure, the carrier switching pattern may be represented as a slot level bitmap with each bit of the bitmap corresponding to one slot and indicating the UE either to switch to carrier #1 or carrier #2 in the corresponding slot. For example, assuming that the bitmap comprises Z bits, the Z bits correspond to Z consecutive slots and are used to indicate the carrier for each of the Z slots. For example, if the corresponding bit of a slot is set to "1" , it indicates to the UE to switch to carrier #1 in this slot, while if the corresponding bit is set to "0" , it indicates to the UE to switch to carrier #2 in this slot; or vice versa.

In some embodiments, a radio frame (e.g., one radio frame such as 10ms) may include an integer number of such carrier switching pattern (i.e., the slot level bitmap) . For example, one radio frame can be evenly divided by the duration of Z slots. Assuming that the SCS configuration for either carrier #1 or carrier #2 is μ1, then one radio frame includes 10×2^μ1 slots and 10×2^μ1 mod Z should be equal to 0. The duration of Z slots can be determined based on the SCS, for example, the carrier switching pattern has a duration of Z×2^﹣μ1 ms. In some cases, Z can be equal to the number of slots within one radio frame. In these cases, each slot within the radio frame has a dedicated bit in the bitmap for indicating the carrier switching pattern.

In other embodiments, a carrier switching pattern may include an integer number of radio frames. For example, the duration of Z slots can be evenly divided by one radio frame. Assuming that the SCS configuration for both carrier #1 and carrier #2 is μ^d, then one radio frame includesslots and Z modshould be equal to 0. For example, in the case of 15 kHz SCS, one radio frame includes 10 slots, and Z may be set to 20 or 40 in order to cover 2 or 4 radio frames within one carrier switching pattern.

The SCS configurations for carrier #1 and carrier #2 can be the same or different.

In some embodiments of the present disclosure, the carrier switching pattern may be represented as a slot group level bitmap with each bit of the bitmap corresponding to one slot group and indicating the UE either to switch to carrier #1 or carrier #2 in the corresponding slot group. For example, assuming that the bitmap comprises K bits and each slot group comprises M consecutive slots, then K bits correspond to K×M consecutive slots and are used to indicate the carrier for each of the K×M slots. Here, M is the number of consecutive slots within a single slot group to reduce signaling overhead. For example, assuming that M is set to 4, then every 4 consecutive slots is grouped as one slot group. If the corresponding bit of a slot group is set to "1" , it indicates to the UE to switch to carrier #1 in this slot group, while if the corresponding bit is set to "0" , it indicates to the UE to switch to carrier #2 in this slot group; or vice versa.

In some embodiments, a radio frame (e.g., one radio frame such as 10ms) may include an integer number of such carrier switching pattern (i.e., the slot group level bitmap) . For example, one radio frame can be evenly divided by the duration of K×M slots. Assuming that the SCS configuration for either carrier #1 or carrier #2 is μ2, then one radio frame includes 10×2^μ2 slots and 10×2^μ2 mod (K×M) should be equal to 0. The duration of K×M slots can be determined based on the SCS, for example, the carrier switching pattern has a duration of K×M×2^﹣μ2 ms. In some cases, K×M can be equal to the number of slots within one radio frame. In these cases, each slot group within the radio frame has a dedicated bit in the bitmap for indicating the carrier switching pattern.

In other embodiments, a carrier switching pattern may include an integer number of radio frames. For example, the duration of K×M slots can be evenly divided by one radio frame. Assuming that the SCS configuration for both carrier #1 and carrier #2 is μ^e, then one radio frame includesslots and (K×M) mod should be equal to 0. For example, in the case of 15 kHz SCS, one radio frame includes 10 slots, and K×M may be set to 20 or 40 in order to cover 2 or 4 radio frames within one carrier switching pattern.

In some embodiments, carrier switching occurs when two adjacent bits in the bitmap (e.g., the slot level bitmap or the slot group level bitmap) indicates different values. For example, a bit (denoted as bit #A1) in the bitmap indicates the UE to switch to carrier #1 and the next bit (denoted as bit #A2) of bit #A1 in the bitmap indicates the UE to switch to carrier #2. Carrier switching may occur at the slot or slot group corresponding to bit #A1 or bit #A2. The carrier switching pattern may include a gap (denoted as gap #A) for the UE to switch from carrier #1 to carrier #2. Gap #A may be located at the end of the slot or slot group corresponding to bit #A1 or at the beginning of the slot or slot group corresponding to bit #A2.

For example, a bit (denoted as bit #B1) in the bitmap (e.g., the slot level bitmap or the slot group level bitmap) indicates the UE to switch to carrier #2 and the next bit (denoted as bit #B2) of bit #B1 in the bitmap indicates the UE to switch to carrier #1. Carrier switching may occur at the slot or slot group corresponding to bit #B1 or bit #B2. For example, the carrier switching pattern may include a gap (denoted as gap #B) for the UE to switch from carrier #2 to carrier #1. Gap #B may be located at located at the end of the slot or slot group corresponding to bit #B1 or at the beginning of the slot or slot group corresponding to bit #B2.

In some embodiments, the number of time domain resources (e.g., the number of symbols) in gap #A or gap #B may be configured via signaling or predefined (e.g., in a standard) . The number of symbols in gap #A and the number of symbols in gap #B may be the same or different. For example, the number of symbols in gap #Acan be set to 1. For example, the number of symbols in gap #B can be set to 1.

FIG. 4A-4C illustrate exemplary carrier switching patterns in accordance with some embodiments of the present disclosure. The illustrated carrier switching patterns may be periodic and can be configured by RRC signaling or a SIB.

Referring to FIG. 4A, carrier switching pattern 400A may include a number of slots for carrier 411, a number of slots for carrier 413, gaps 415 for switching from carrier 411 to carrier 413 and gap 417 for switching from carrier 413 to carrier 411. In some embodiments, one or more of gaps 415 and 417 may not exist. According to carrier switching pattern 400A, transmission and/or reception on one of carrier 411 and carrier 413 and transmission on the other of carrier 411 and carrier 413 cannot happen simultaneously. In some embodiments, carrier 411 may be carrier #1 and carrier 413 may be carrier #2. In some embodiments, carrier 411 may be carrier #2 and carrier 413 may be carrier #1.

In some embodiments, carrier switching pattern 400A may be configured as a slot level bitmap, each bit may correspond to one slot (e.g., 450) and indicate the UE to switch to either carrier 411 or carrier 413 in the corresponding slot. Gaps 415 and 417 are located at one of two adjacent slots which correspond to different bit values in the bitmap. In some embodiments, carrier switching pattern 400A may be configured as a slot group level bitmap, each bit may correspond to one slot group (e.g., 451) and indicate the UE to switch to either carrier 411 or carrier 413 in the corresponding slot group. Gaps 415 and 417 are located at one of two adjacent slot groups which correspond to different bit values in the bitmap. As shown in FIG. 4A, gaps 415 are located at the beginning of the first slot after the carrier switching from carrier 411 to carrier 413, and gap 417 is located at the beginning of the first slot after the carrier switching from carrier 413 to carrier 411.

Referring to FIG. 4B, carrier switching pattern 400B may include a number of slots for carrier 421, a number of slots for carrier 423, gaps 425 for switching from carrier 421 to carrier 423 and gap 427 for switching from carrier 423 to carrier 421. In some embodiments, one or more of gaps 425 and 427 may not exist. According to carrier switching pattern 400B, transmission and/or reception on one of carrier 421 and carrier 423 and transmission on the other of carrier 421 and carrier 423 cannot happen simultaneously. In some embodiments, carrier 421 may be carrier #1 and carrier 423 may be carrier #2. In some embodiments, carrier 421 may be carrier #2 and carrier 423 may be carrier #1.

In some embodiments, carrier switching pattern 400B may be configured as a slot level bitmap, each bit may correspond to one slot (e.g., 452) and indicate the UE to switch to either carrier 421 or carrier 423 in the corresponding slot. Gaps 425 and 427 are located at one of two adjacent slots which correspond to different bit values in the bitmap. In some embodiments, carrier switching pattern 400B may be configured as a slot group level bitmap, each bit may correspond to one slot group (e.g., 453) and indicate the UE to switch to either carrier 421 or carrier 423 in the corresponding slot group. Gaps 425 and 427 are located at one of two adjacent slot groups which correspond to different bit values in the bitmap. As shown in FIG. 4B, gaps 425 are located at the beginning of the first slot after the carrier switching from carrier 421 to carrier 423, and gap 427 is located at the end of the last slot before the carrier switching from carrier 423 to carrier 421.

Referring to FIG. 4C, carrier switching pattern 400C may include a number of slots for carrier 431, a number of slots for carrier 433, gaps 435 for switching from carrier 431 to carrier 433 and gap 437 for switching from carrier 433 to carrier 431. In some embodiments, one or more of gaps 435 and 437 may not exist. According to carrier switching pattern 400C, transmission and/or reception on one of carrier 431 and carrier 433 and transmission on the other of carrier 431 and carrier 433 cannot happen simultaneously. In some embodiments, carrier 431 may be carrier #1 and carrier 433 may be carrier #2. In some embodiments, carrier 431 may be carrier #2 and carrier 433 may be carrier #1.

In some embodiments, carrier switching pattern 400C may be configured as a slot level bitmap, each bit may correspond to one slot (e.g., 454) and indicate the UE to switch to either carrier 431 or carrier 433 in the corresponding slot. Gaps 435 and 437 are located at one of two adjacent slots which correspond to different bit values in the bitmap. In some embodiments, carrier switching pattern 400C may be configured as a slot group level bitmap, each bit may correspond to one slot group (e.g., 455) and indicate the UE to switch to either carrier 431 or carrier 433 in the corresponding slot group. Gaps 435 and 437 are located at one of two adjacent slot groups which correspond to different bit values in the bitmap. As shown in FIG. 4C, gaps 435 are located at the end of the last slot before the carrier switching from carrier 431 to carrier 433, and gap 437 is located at the end of the last slot before the carrier switching from carrier 433 to carrier 431.

Referring to FIG. 4D, carrier switching pattern 400D may include a number of slots for carrier 441, a number of slots for carrier 443, gaps 445 for switching from carrier 441 to carrier 443 and gap 447 for switching from carrier 443 to carrier 441. In some embodiments, one or more of gaps 445 and 447 may not exist. According to carrier switching pattern 400D, transmission and/or reception on one of carrier 441 and carrier 443 and transmission on the other of carrier 441 and carrier 443 cannot happen simultaneously. In some embodiments, carrier 441 may be carrier #1 and carrier 443 may be carrier #2. In some embodiments, carrier 441 may be carrier #2 and carrier 443 may be carrier #1.

In some embodiments, carrier switching pattern 400D may be configured as a slot level bitmap, each bit may correspond to one slot (e.g., 456) and indicate the UE to switch to either carrier 441 or carrier 443 in the corresponding slot. Gaps 445 and 447 are located at one of two adjacent slots which correspond to different bit values in the bitmap. In some embodiments, carrier switching pattern 400D may be configured as a slot group level bitmap, each bit may correspond to one slot group (e.g., 457) and indicate the UE to switch to either carrier 441 or carrier 443 in the corresponding slot group. Gaps 445 and 447 are located at one of two adjacent slot groups which correspond to different bit values in the bitmap. As shown in FIG. 4D, gaps 445 are located at the end of the last slot before the carrier switching from carrier 441 to carrier 443, and gap 447 is located at the beginning of the first slot after the carrier switching from carrier 443 to carrier 441.

From the perspective of a BS, the BS can transmit downlink signals or channels within the switching gap (e.g., gap 415 or 417 in FIG. 4A, gap 425 or 427 in FIG. 4B, gap 435 or 437 in FIG. 4C or gap 445 or 447 in FIG. 4D) and repeat the downlink signals or channels from the first symbol after the switching. These downlink signals or channels within the switching gap can be used as AGC symbols for the UE to adjust the Rx chain. From the perspective of a UE, the UE does not expect to receive downlink signals or channels or transmit uplink signals or channels within the switching gap.

The carrier switching pattern (e.g., carrier switching pattern 400A in FIG. 4A, carrier switching pattern 400B in FIG. 4B, carrier switching pattern 400C in FIG. 4C or carrier switching pattern 400D in FIG. 4D) may be started from one specific (e.g., the first) slot of a radio frame and repeated until another specific (e.g., the last) slot of the radio frame. Such repetition may be continued in the subsequent radio frames.

FIG. 5 illustrates a flowchart of method 500 for wireless communication in accordance with some embodiments of the present disclosure. Details described in all of the foregoing embodiments of the present disclosure are applicable for the embodiments shown in FIG. 5. In some examples, method 500 may be performed by a UE. In some embodiments, the UE may execute a set of instructions to control the functional elements of the UE to perform the described functions or operations. In some examples, a processor of the UE may cause the UE to perform method 500.

At 511, a UE may receive signaling indicating a carrier switching pattern, wherein the carrier switching pattern includes a first number of slots for the UE to receive a downlink transmission or transmit an uplink transmission on a first carrier and a second number of slots for the UE to receive a downlink transmission on a second carrier. The carrier switching pattern may further includes a gap between the first number of slots and the second number of slots in the time domain. That is, the first number of slots and the second number of slots may not overlap in the time domain.

At 513, the UE may transmit, on the first carrier, HARQ-ACK feedback for the downlink transmission received by the UE on the first carrier within the first number of slots and for the downlink transmission received by the UE on the second carrier within the second number of slots, or transmit the uplink transmission on the first carrier within the first number of slots.

In some embodiments, the UE may: monitor a PDCCH on the first carrier within the first number of slots and on the second carrier within the second number of slots; or monitor a PDCCH only on the first carrier within the first number of slots.

It should be appreciated by persons skilled in the art that the sequence of the operations in exemplary method 500 may be changed and some of the operations in exemplary method 500 may be eliminated or modified, without departing from the spirit and scope of the disclosure.

FIG. 6 illustrates a flowchart of method 600 for wireless communication in accordance with some embodiments of the present disclosure. Details described in all of the foregoing embodiments of the present disclosure are applicable for the embodiments shown in FIG. 6. In some examples, method 600 may be performed by a BS. In some embodiments, the BS may execute a set of instructions to control the functional elements of the BS to perform the described functions or operations. In some examples, a processor of the BS may cause the BS to perform method 600.

At 611, a BS may transmit, to a UE, signaling indicating a carrier switching pattern, wherein the carrier switching pattern includes a first number of slots for the UE to receive a downlink transmission or transmit an uplink transmission on a first carrier and a second number of slots for the UE to receive a downlink transmission on a second carrier. The carrier switching pattern may further includes a gap between the first number of slots and the second number of slots in the time domain. That is, the first number of slots and the second number of slots may not overlap in the time domain.

At 613, the BS may receive, from the UE on the first carrier, HARQ-ACK feedback for the downlink transmission received by the UE on the first carrier within the first number of slots and for the downlink transmission received by the UE on the second carrier within the second number of slots, or receive from the UE the uplink transmission on the first carrier within the first number of slots.

In some embodiments, the BS may: transmit a PDCCH on the first carrier within the first number of slots or on the second carrier within the second number of slots; or transmit a PDCCH only on the first carrier within the first number of slots.

In some embodiments, the BS may configure at least one of a number of symbols in the first gap or a number of symbols in the second gap for the UE. In some embodiments, at least one of the number of symbols in the first gap or the number of symbols in the second gap is predefined.

It should be appreciated by persons skilled in the art that the sequence of the operations in exemplary method 600 may be changed and some of the operations in exemplary method 600 may be eliminated or modified, without departing from the spirit and scope of the disclosure.

FIG. 7 illustrates an example of a UE 700 in accordance with aspects of the present disclosure. The UE 700 may include a processor 702, a memory 704, a controller 706, and a transceiver 708. The processor 702, the memory 704, the controller 706, or the transceiver 708, or various combinations thereof or various components thereof may be examples of means for performing various aspects of the present disclosure as described herein. These components may be coupled (e.g., operatively, communicatively, functionally, electronically, electrically) via one or more interfaces.

The processor 702, the memory 704, the controller 706, or the transceiver 708, or various combinations or components thereof may be implemented in hardware (e.g., circuitry) . The hardware may include a processor, a digital signal processor (DSP) , an application-specific integrated circuit (ASIC) , or other programmable logic device, or any combination thereof configured as or otherwise supporting a means for performing the functions described in the present disclosure.

The processor 702 may include an intelligent hardware device (e.g., a general-purpose processor, a DSP, a CPU, an ASIC, an FPGA, or any combination thereof) . In some implementations, the processor 702 may be configured to operate the memory 704. In some other implementations, the memory 704 may be integrated into the processor 702. The processor 702 may be configured to execute computer-readable instructions stored in the memory 704 to cause the UE 700 to perform various functions of the present disclosure.

The memory 704 may include volatile or non-volatile memory. The memory 704 may store computer-readable, computer-executable code including instructions when executed by the processor 702 cause the UE 700 to perform various functions described herein. The code may be stored in a non-transitory computer-readable medium such as the memory 704 or another type of memory. Computer-readable media includes both non-transitory computer storage media and communication media including any medium that facilitates transfer of a computer program from one place to another. A non-transitory storage medium may be any available medium that may be accessed by a general-purpose or special-purpose computer.

In some implementations, the processor 702 and the memory 704 coupled with the processor 702 may be configured to cause the UE 700 to perform one or more of the functions described herein (e.g., executing, by the processor 702, instructions stored in the memory 704) . For example, the processor 702 may support wireless communication at the UE 700 in accordance with examples as disclosed herein. For example, the UE 700 may be configured to support means for performing the operations as described with respect to FIGs. 1-6.

For example, the UE 700 may be configured to support: a means for receiving signaling indicating a carrier switching pattern, wherein the carrier switching pattern includes a first number of slots for the UE to receive a downlink transmission or transmit an uplink transmission on a first carrier, a second number of slots for the UE to receive a downlink transmission on a second carrier, and a gap between the first number of slots and the second number of slots in a time domain; and a means for transmitting, on the first carrier, HARQ-ACK feedback for the downlink transmission received by the UE on the first carrier within the first number of slots and for the downlink transmission received by the UE on the second carrier within the second number of slots, or transmitting the uplink transmission on the first carrier within the first number of slots.

The controller 706 may manage input and output signals for the UE 700. The controller 706 may also manage peripherals not integrated into the UE 700. In some implementations, the controller 706 may utilize an operating system such as or other operating systems. In some implementations, the controller 706 may be implemented as part of the processor 702.

In some implementations, the UE 700 may include at least one transceiver 708. In some other implementations, the UE 700 may have more than one transceiver 708. The transceiver 708 may represent a wireless transceiver. The transceiver 708 may include one or more receiver chains 710, one or more transmitter chains 712, or a combination thereof.

A receiver chain 710 may be configured to receive signals (e.g., control information, data, or packets) over a wireless medium. For example, the receiver chain 710 may include one or more antennas for receive the signal over the air or wireless medium. The receiver chain 710 may include at least one amplifier (e.g., a low-noise amplifier (LNA) ) configured to amplify the received signal. The receiver chain 710 may include at least one demodulator configured to demodulate the receive signal and obtain the transmitted data by reversing the modulation technique applied during transmission of the signal. The receiver chain 710 may include at least one decoder for decoding the processing the demodulated signal to receive the transmitted data.

A transmitter chain 712 may be configured to generate and transmit signals (e.g., control information, data, or packets) . The transmitter chain 712 may include at least one modulator for modulating data onto a carrier signal, preparing the signal for transmission over a wireless medium. The at least one modulator may be configured to support one or more techniques such as amplitude modulation (AM) , frequency modulation (FM) , or digital modulation schemes like phase-shift keying (PSK) or quadrature amplitude modulation (QAM) . The transmitter chain 712 may also include at least one power amplifier configured to amplify the modulated signal to an appropriate power level suitable for transmission over the wireless medium. The transmitter chain 712 may also include one or more antennas for transmitting the amplified signal into the air or wireless medium.

It should be appreciated by persons skilled in the art that the components in exemplary UE 700 may be changed, for example, some of the components in exemplary UE 700 may be omitted or modified or a new component (s) may be added to exemplary UE 700, without departing from the spirit and scope of the disclosure. For example, in some embodiments, the UE 700 may not include the controller 706.

FIG. 8 illustrates an example of a processor 800 in accordance with aspects of the present disclosure. The processor 800 may be an example of a processor configured to perform various operations in accordance with examples as described herein. The processor 800 may include a controller 802 configured to perform various operations in accordance with examples as described herein. The processor 800 may optionally include at least one memory 804, which may be, for example, an L1/L2/L3 cache. Additionally, or alternatively, the processor 800 may optionally include one or more arithmetic-logic units (ALUs) 806. One or more of these components may be in electronic communication or otherwise coupled (e.g., operatively, communicatively, functionally, electronically, electrically) via one or more interfaces (e.g., buses) .

The processor 800 may be a processor chipset and include a protocol stack (e.g., a software stack) executed by the processor chipset to perform various operations (e.g., receiving, obtaining, retrieving, transmitting, outputting, forwarding, storing, determining, identifying, accessing, writing, reading) in accordance with examples as described herein. The processor chipset may include one or more cores, one or more caches (e.g., memory local to or included in the processor chipset (e.g., the processor 800) or other memory (e.g., random access memory (RAM) , read-only memory (ROM) , dynamic RAM (DRAM) , synchronous dynamic RAM (SDRAM) , static RAM (SRAM) , ferroelectric RAM (FeRAM) , magnetic RAM (MRAM) , resistive RAM (RRAM) , flash memory, phase change memory (PCM) , and others) .

The controller 802 may be configured to manage and coordinate various operations (e.g., signaling, receiving, obtaining, retrieving, transmitting, outputting, forwarding, storing, determining, identifying, accessing, writing, reading) of the processor 800 to cause the processor 800 to support various operations in accordance with examples as described herein. For example, the controller 802 may operate as a control unit of the processor 800, generating control signals that manage the operation of various components of the processor 800. These control signals include enabling or disabling functional units, selecting data paths, initiating memory access, and coordinating timing of operations.

The controller 802 may be configured to fetch (e.g., obtain, retrieve, receive) instructions from the memory 804 and determine a subsequent instruction (s) to be executed to cause the processor 800 to support various operations in accordance with examples as described herein. The controller 802 may be configured to track memory address of instructions associated with the memory 804. The controller 802 may be configured to decode instructions to determine the operation to be performed and the operands involved. For example, the controller 802 may be configured to interpret the instruction and determine control signals to be output to other components of the processor 800 to cause the processor 800 to support various operations in accordance with examples as described herein. Additionally, or alternatively, the controller 802 may be configured to manage flow of data within the processor 800. The controller 802 may be configured to control transfer of data between registers, ALUs, and other functional units of the processor 800.

The memory 804 may include one or more caches (e.g., memory local to or included in the processor 800 or other memory, such RAM, ROM, DRAM, SDRAM, SRAM, MRAM, flash memory, etc. In some implementations, the memory 804 may reside within or on a processor chipset (e.g., local to the processor 800) . In some other implementations, the memory 804 may reside external to the processor chipset (e.g., remote to the processor 800) .

The memory 804 may store computer-readable, computer-executable code including instructions that, when executed by the processor 800, cause the processor 800 to perform various functions described herein. The code may be stored in a non-transitory computer-readable medium such as system memory or another type of memory. The controller 802 and/or the processor 800 may be configured to execute computer-readable instructions stored in the memory 804 to cause the processor 800 to perform various functions. For example, the processor 800 and/or the controller 802 may be coupled with or to the memory 804, the processor 800, the controller 802, and the memory 804 may be configured to perform various functions described herein. In some examples, the processor 800 may include multiple processors and the memory 804 may include multiple memories. One or more of the multiple processors may be coupled with one or more of the multiple memories, which may, individually or collectively, be configured to perform various functions herein.

The one or more ALUs 806 may be configured to support various operations in accordance with examples as described herein. In some implementations, the one or more ALUs 806 may reside within or on a processor chipset (e.g., the processor 800) . In some other implementations, the one or more ALUs 806 may reside external to the processor chipset (e.g., the processor 800) . One or more ALUs 806 may perform one or more computations such as addition, subtraction, multiplication, and division on data. For example, one or more ALUs 806 may receive input operands and an operation code, which determines an operation to be executed. One or more ALUs 806 be configured with a variety of logical and arithmetic circuits, including adders, subtractors, shifters, and logic gates, to process and manipulate the data according to the operation. Additionally, or alternatively, the one or more ALUs 806 may support logical operations such as AND, OR, exclusive-OR (XOR) , not-OR (NOR) , and not-AND (NAND) , enabling the one or more ALUs 806 to handle conditional operations, comparisons, and bitwise operations.

The processor 800 may support wireless communication in accordance with examples as disclosed herein. For example, the processor 800 may be configured to support means for performing the operations as described with respect to FIGs. 1-6.

For example, the processor 800 may be configured to or operable to support: a means for receiving signaling indicating a carrier switching pattern, wherein the carrier switching pattern includes a first number of slots for a UE including the processor 800 to receive a downlink transmission or transmit an uplink transmission on a first carrier, a second number of slots for the UE to receive a downlink transmission on a second carrier, and a gap between the first number of slots and the second number of slots in a time domain; and a means for transmitting, on the first carrier, HARQ-ACK feedback for the downlink transmission received by the UE on the first carrier within the first number of slots and for the downlink transmission received by the UE on the second carrier within the second number of slots, or transmitting the uplink transmission on the first carrier within the first number of slots.

For example, the processor 800 may be configured to or operable to support: a means for transmitting, to a UE, signaling indicating a carrier switching pattern, wherein the carrier switching pattern includes a first number of slots for the UE to receive a downlink transmission or transmit an uplink transmission on a first carrier, a second number of slots for the UE to receive a downlink transmission on a second carrier, and a gap between the first number of slots and the second number of slots in a time domain; and a means for receiving, from the UE on the first carrier, HARQ-ACK feedback for the downlink transmission received by the UE on the first carrier within the first number of slots and for the downlink transmission received by the UE on the second carrier within the second number of slots, or receiving from the UE the uplink transmission on the first carrier within the first number of slots.

It should be appreciated by persons skilled in the art that the components in exemplary processor 800 may be changed, for example, some of the components in exemplary processor 800 may be omitted or modified or a new component (s) may be added to exemplary processor 800, without departing from the spirit and scope of the disclosure. For example, in some embodiments, the processor 800 may not include the ALUs 806.

FIG. 9 illustrates an example of an NE 900 in accordance with aspects of the present disclosure. The NE 900 may include a processor 902, a memory 904, a controller 906, and a transceiver 908. The processor 902, the memory 904, the controller 906, or the transceiver 908, or various combinations thereof or various components thereof may be examples of means for performing various aspects of the present disclosure as described herein. These components may be coupled (e.g., operatively, communicatively, functionally, electronically, electrically) via one or more interfaces.

The processor 902, the memory 904, the controller 906, or the transceiver 908, or various combinations or components thereof may be implemented in hardware (e.g., circuitry) . The hardware may include a processor, a DSP, an ASIC, or other programmable logic device, or any combination thereof configured as or otherwise supporting a means for performing the functions described in the present disclosure.

The processor 902 may include an intelligent hardware device (e.g., a general-purpose processor, a DSP, a CPU, an ASIC, an FPGA, or any combination thereof) . In some implementations, the processor 902 may be configured to operate the memory 904. In some other implementations, the memory 904 may be integrated into the processor 902. The processor 902 may be configured to execute computer-readable instructions stored in the memory 904 to cause the NE 900 to perform various functions of the present disclosure.

The memory 904 may include volatile or non-volatile memory. The memory 904 may store computer-readable, computer-executable code including instructions when executed by the processor 902 cause the NE 900 to perform various functions described herein. The code may be stored in a non-transitory computer-readable medium such as the memory 904 or another type of memory. Computer-readable media includes both non-transitory computer storage media and communication media including any medium that facilitates transfer of a computer program from one place to another. A non-transitory storage medium may be any available medium that may be accessed by a general-purpose or special-purpose computer.

In some implementations, the processor 902 and the memory 904 coupled with the processor 902 may be configured to cause the NE 900 to perform one or more of the functions described herein (e.g., executing, by the processor 902, instructions stored in the memory 904) . For example, the processor 902 may support wireless communication at the NE 900 in accordance with examples as disclosed herein. For example, the NE 900 may be configured to support means for performing the operations as described with respect to FIGs. 1-6.

For example, the NE 900 may be configured to support: a means for transmitting, to a UE, signaling indicating a carrier switching pattern, wherein the carrier switching pattern includes a first number of slots for the UE to receive a downlink transmission or transmit an uplink transmission on a first carrier, a second number of slots for the UE to receive a downlink transmission on a second carrier, and a gap between the first number of slots and the second number of slots in a time domain; and a means for receiving, from the UE on the first carrier, HARQ-ACK feedback for the downlink transmission received by the UE on the first carrier within the first number of slots and for the downlink transmission received by the UE on the second carrier within the second number of slots, or receiving from the UE the uplink transmission on the first carrier within the first number of slots.

The controller 906 may manage input and output signals for the NE 900. The controller 906 may also manage peripherals not integrated into the NE 900. In some implementations, the controller 906 may utilize an operating system such as or other operating systems. In some implementations, the controller 906 may be implemented as part of the processor 902.

In some implementations, the NE 900 may include at least one transceiver 908. In some other implementations, the NE 900 may have more than one transceiver 908. The transceiver 908 may represent a wireless transceiver. The transceiver 908 may include one or more receiver chains 910, one or more transmitter chains 912, or a combination thereof.

A receiver chain 910 may be configured to receive signals (e.g., control information, data, or packets) over a wireless medium. For example, the receiver chain 910 may include one or more antennas for receive the signal over the air or wireless medium. The receiver chain 910 may include at least one amplifier (e.g., an LNA) configured to amplify the received signal. The receiver chain 910 may include at least one demodulator configured to demodulate the receive signal and obtain the transmitted data by reversing the modulation technique applied during transmission of the signal. The receiver chain 910 may include at least one decoder for decoding the processing the demodulated signal to receive the transmitted data.

A transmitter chain 912 may be configured to generate and transmit signals (e.g., control information, data, or packets) . The transmitter chain 912 may include at least one modulator for modulating data onto a carrier signal, preparing the signal for transmission over a wireless medium. The at least one modulator may be configured to support one or more techniques such as AM, FM, or digital modulation schemes like PSK or QAM. The transmitter chain 912 may also include at least one power amplifier configured to amplify the modulated signal to an appropriate power level suitable for transmission over the wireless medium. The transmitter chain 912 may also include one or more antennas for transmitting the amplified signal into the air or wireless medium.

It should be appreciated by persons skilled in the art that the components in exemplary NE 900 may be changed, for example, some of the components in exemplary NE 900 may be omitted or modified or a new component (s) may be added to exemplary NE 900, without departing from the spirit and scope of the disclosure. For example, in some embodiments, the NE 900 may not include the controller 906.

Those having ordinary skill in the art would understand that the operations or steps of the methods described in connection with the aspects disclosed herein may be embodied directly in hardware, in a software module executed by a processor, or in a combination of the two. A software module may reside in RAM memory, flash memory, ROM memory, EPROM memory, EEPROM memory, registers, a hard disk, a removable disk, a CD-ROM, or any other form of storage medium known in the art. Additionally, in some aspects, the operations or steps of the methods may reside as one or any combination or set of codes and/or instructions on a non-transitory computer-readable medium, which may be incorporated into a computer program product.

While this disclosure has been described with specific embodiments thereof, it is evident that many alternatives, modifications, and variations may be apparent to those skilled in the art. The disclosure is not limited to the examples and designs described herein but is to be accorded with the broadest scope consistent with the principles and novel features disclosed herein. For example, various components of the embodiments may be interchanged, added, or substituted in other embodiments. Also, all of the elements of each figure are not necessary for the operation of the disclosed embodiments. For example, one of ordinary skill in the art of the disclosed embodiments would be enabled to make and use the teachings of the disclosure by simply employing the elements of the independent claims. Accordingly, embodiments of the disclosure as set forth herein are intended to be illustrative, not limiting. Various changes may be made without departing from the spirit and scope of the disclosure.

In this document, the terms "includes, " "including, " or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that includes a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus. An element proceeded by "a, " "an, " or the like does not, without more constraints, preclude the existence of additional identical elements in the process, method, article, or apparatus that includes the element. Also, the term "another" is defined as at least a second or more. The term "having" or the like, as used herein, is defined as "including. " Expressions such as "A and/or B" or "at least one of A and B" may include any and all combinations of words enumerated along with the expression. For instance, the expression "A and/or B" or "at least one of A and B" may include A, B, or both A and B. The wording "the first, " "the second" or the like is only used to clearly illustrate the embodiments of the present disclosure, but is not used to limit the substance of the present disclosure.

Claims

A user equipment (UE) , comprising:

at least one memory; and

at least one processor coupled with the at least one memory and configured to cause the UE to:

receive signaling indicating a carrier switching pattern, wherein the carrier switching pattern comprises a first number of slots for the UE to receive a downlink transmission or transmit an uplink transmission on a first carrier, a second number of slots for the UE to receive a downlink transmission on a second carrier, and a gap between the first number of slots and the second number of slots in a time domain; and

transmit, on the first carrier, hybrid automatic repeat request acknowledgement (HARQ-ACK) feedback for the downlink transmission received by the UE on the first carrier within the first number of slots and for the downlink transmission received by the UE on the second carrier within the second number of slots, or transmit the uplink transmission on the first carrier within the first number of slots.
The UE of claim 1, wherein the gap comprises a first gap for the UE to switch from the first carrier to the second carrier and the carrier switching pattern further comprises a second gap for the UE to switch from the second carrier to the first carrier.
The UE of claim 2, wherein the first gap is located after the first number of slots and before the second number of slots, and the second gap is located after or at an end of the second number of slots.
The UE of claim 3, wherein the signaling indicates one or more of the following parameters for the carrier switching pattern:

a period of the carrier switching pattern;

a value of the first number;

a value of the second number;

a third number of symbols for the UE to receive a downlink transmission or transmit an uplink transmission on the first carrier, the third number of symbols being located immediately after the first number of slots;

a fourth number of symbols for the UE to receive a downlink transmission on the second carrier, the fourth number of symbols being located immediately before the second number of slots; and

a fifth number of symbols for the UE to receive a downlink transmission on the second carrier, the fifth number of symbols being located between the second number of slots and the second gap, or immediately before the second gap within the second number of slots.
The UE of claim 2, wherein the second number of slots is located after the first number of slots, the first gap is located at a beginning of the second number of slots or at an end of the first number of slots, and the second gap is located at an end of the second number of slots.
The UE of claim 5, wherein the signaling indicates one or more of the following parameters for the carrier switching pattern:

a period of the carrier switching pattern;

a value of the first number;

a value of the second number;

a number of symbols within the first gap; and

a number of symbols within the second gap.
The UE of claim 2, wherein the signaling indicates a bitmap for the carrier switching pattern, and each bit in the bitmap:

corresponds to one slot and indicates the UE either to switch to the first carrier or the second carrier in a corresponding slot, or

corresponds to one slot group and indicates the UE either to switch to the first carrier or the second carrier in a corresponding slot group.
The UE of claim 7, wherein a first bit in the bitmap indicates the UE to switch to the first carrier and a second bit next to the first bit in the bitmap indicates the UE to switch to the second carrier; and

wherein the first gap is located at an end of a slot or slot group corresponding to the first bit or at a beginning of a slot or slot group corresponding to the second bit.
The UE of claim 7, wherein a first bit in the bitmap indicates the UE to switch to the second carrier and a second bit next to the first bit in the bitmap indicates the UE to switch to the first carrier; and

wherein the second gap is located at an end of a slot or slot group corresponding to the first bit or at a beginning of a slot or slot group corresponding to the second bit.
A base station (BS) , comprising:

at least one memory; and

at least one processor coupled with the at least one memory and configured to cause the BS to:

transmit, to a user equipment (UE) , signaling indicating a carrier switching pattern, wherein the carrier switching pattern comprises a first number of slots for the UE to receive a downlink transmission or transmit an uplink transmission on a first carrier, a second number of slots for the UE to receive a downlink transmission on a second carrier, and a gap between the first number of slots and the second number of slots in a time domain; and

receive, from the UE on the first carrier, hybrid automatic repeat request acknowledgement (HARQ-ACK) feedback for the downlink transmission received by the UE on the first carrier within the first number of slots and for the downlink transmission received by the UE on the second carrier within the second number of slots, or receive from the UE the uplink transmission on the first carrier within the first number of slots.
The BS of claim 10, wherein the gap comprises a first gap for the UE to switch from the first carrier to the second carrier and the carrier switching pattern further comprises a second gap for the UE to switch from the second carrier to the first carrier.
The BS of claim 11, wherein the first gap is located after the first number of slots and before the second number of slots, and the second gap is located after or at an end of the second number of slots.
The BS of claim 12, wherein the signaling indicates one or more of the following parameters for the carrier switching pattern:

a period of the carrier switching pattern;

a value of the first number;

a value of the second number;

a third number of symbols for the UE to receive a downlink transmission or transmit an uplink transmission on the first carrier, the third number of symbols being located immediately after the first number of slots;

a fourth number of symbols for the UE to receive a downlink transmission on the second carrier, the fourth number of symbols being located immediately before the second number of slots; and

a fifth number of symbols for the UE to receive a downlink transmission on the second carrier, the fifth number of symbols being located between the second number of slots and the second gap, or immediately before the second gap within the second number of slots.
The BS of claim 11, wherein the second number of slots is located after the first number of slots, the first gap is located at a beginning of the second number of slots or at an end of the first number of slots, and the second gap is located at an end of the second number of slots.
The BS of claim 14, wherein the signaling indicates one or more of the following parameters for the carrier switching pattern:

a period of the carrier switching pattern;

a value of the first number;

a value of the second number;

a number of symbols within the first gap; and

a number of symbols within the second gap.
The BS of claim 11, wherein the signaling indicates a bitmap for the carrier switching pattern, and each bit in the bitmap:

corresponds to one slot and indicates the UE either to switch to the first carrier or the second carrier in a corresponding slot, or

corresponds to one slot group and indicates the UE either to switch to the first carrier or the second carrier in a corresponding slot group.
The BS of claim 16, wherein a first bit in the bitmap indicates the UE to switch to the first carrier and a second bit next to the first bit in the bitmap indicates the UE to switch to the second carrier; and

wherein the first gap is located at an end of a slot or slot group corresponding to the first bit or at a beginning of a slot or slot group corresponding to the second bit.
The BS of claim 16, wherein a first bit in the bitmap indicates the UE to switch to the second carrier and a second bit next to the first bit in the bitmap indicates the UE to switch to the first carrier; and

wherein the second gap is located at an end of a slot or slot group corresponding to the first bit or at a beginning of a slot or slot group corresponding to the second bit.
A processor, comprising:

at least one controller coupled with at least one memory and configured to cause the processor to:

receive signaling indicating a carrier switching pattern, wherein the carrier switching pattern comprises a first number of slots for a user equipment (UE) to receive a downlink transmission or transmit an uplink transmission on a first carrier, a second number of slots for the UE to receive a downlink transmission on a second carrier, and a gap between the first number of slots and the second number of slots in a time domain; and

transmit, on the first carrier, hybrid automatic repeat request acknowledgement (HARQ-ACK) feedback for the downlink transmission received by the UE on the first carrier within the first number of slots and for the downlink transmission received by the UE on the second carrier within the second number of slots, or transmit the uplink transmission on the first carrier within the first number of slots.
A method for wireless communication, comprising:

receiving signaling indicating a carrier switching pattern, wherein the carrier switching pattern comprises a first number of slots for a user equipment (UE) to receive a downlink transmission or transmit an uplink transmission on a first carrier, a second number of slots for the UE to receive a downlink transmission on a second carrier, and a gap between the first number of slots and the second number of slots in a time domain; and

transmitting, on the first carrier, hybrid automatic repeat request acknowledgement (HARQ-ACK) feedback for the downlink transmission received by the UE on the first carrier within the first number of slots and for the downlink transmission received by the UE on the second carrier within the second number of slots, or transmitting the uplink transmission on the first carrier within the first number of slots.