Method and user equipment for switching active bandwidth portion in carrier aggregation

Abstract

The present invention provides a method and user equipment for switching active bandwidth parts (BWPs) in carrier aggregation (CA). To avoid longer switching delays and multiple interruptions in other component carriers (CCs) / cells, the start time of a later active BWP switch in one cell should fall outside the switching delay of an earlier active BWP switch in another cell. If the later active BWP switch is based on DCI, the network should schedule the later active BWP switch outside the switching delay of the earlier active BWP switch. If the later active BWP switch is based on a timer, the UE should not perform the later active BWP switch until the earlier active BWP switch is completed.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application is a divisional application. The application number of the original application is 201980013528.3, the application date is September 27, 2019, and the name of the invention is “Method and user equipment for switching active bandwidth portion in carrier aggregation”; this application claims priority under 35 U.S.C. §119 to U.S. Provisional Application No. 62 / 737,225 entitled “Method for switching active bandwidth portion in carrier aggregation” filed on September 27, 2018, U.S. Provisional Application No. 62 / 738,063 entitled “Method for switching active bandwidth portion in carrier aggregation” filed on September 28, 2018, and U.S. Provisional Application No. 16 / 578,945 entitled “Method for switching active bandwidth portion in carrier aggregation” filed on September 23, 2019, the subject matter of which is incorporated herein by reference. Technical Field

[0003] The disclosed embodiments relate generally to wireless network communications, and more particularly to bandwidth part (BWP) switching with carrier aggregation (CA) in a 5G new radio (NR) wireless communication system. Background Art

[0004] The Third Generation Partnership Project (3GPP) and Long-Term Evolution (LTE) mobile telecommunication systems offer high data rates, lower latency, and improved system performance. In 3GPP LTE networks, the evolved universal terrestrial radio access network (E-UTRAN) includes multiple base stations, such as evolved Node-Bs (eNBs), that communicate with multiple mobile stations, known as user equipment (UEs). Orthogonal Frequency Division Multiple Access (OFDMA) has been chosen as the LTE downlink (DL) radio access scheme due to its robustness to multipath fading, higher spectrum efficiency, and bandwidth scalability. Multiple access in the downlink is achieved by allocating different subbands (i.e., groups of subcarriers, denoted as resource blocks (RBs)) of the system bandwidth to each user based on their existing channel conditions.

[0005] The increasing bandwidth shortage experienced by mobile carriers has stimulated the exploration of underutilized millimeter wave (mmWave) spectrum around 30G and 300GHz for next-generation 5G broadband cellular communication networks. The available spectrum in the mmWave band is 200 times that of traditional cellular systems. mmWave wireless networks use directional communications with narrow beams and can support multi-gigabit data rates. 5G NR beamforming wireless systems support UEs operating simultaneously using a single broadband carrier and UEs operating using intra-band carrier aggregation on the same continuous spectrum.

[0006] In addition, to save power, NR introduces the concept of BWP, which consists of a continuous range of physical resource blocks (PRBs) in the frequency domain, and the bandwidth it occupies is a subset of the associated carrier bandwidth. That is, the bandwidth of the BWP in the carrier is a subset of the carrier bandwidth, where the carrier bandwidth is divided into multiple continuous frequency bands with smaller bandwidths. The UE can be configured with a network with multiple uplink (UL) BWPs and DL BWPs, and the UE is required to monitor at most one uplink BWP and downlink BWP at the same time. The downlink BWP and uplink BWP that the UE is using or monitoring are called active BWPs, for example, active DL BWPs and active UL BWPs, respectively. Since the UE is only required to monitor the smaller frequency range of the active BWP, rather than the entire carrier bandwidth, the power consumption used to monitor the downlink can be reduced. Each uplink bandwidth portion and downlink bandwidth portion has its own identifier, namely BWP ID. In an FDD system (i.e., paired spectrum system), the UE can operate in an active UL BWP and an active DL BWP with different BWP IDs (e.g., using UL BWP#1 and DL BWP 2); while for a TDD system (i.e., unpaired spectrum system), the UE always operates on a UL BWP and a DL BWP with the same BWP ID.

[0007] Under carrier aggregation, for each UE-specific serving cell, one or more DL BWPs and one or more UL BWPs can be configured for the UE through dedicated signaling. Each UE's serving cell has at most one active DL BWP and one active UL BWP at a given time. The activation or deactivation of the BWP can be achieved through radio resource control (RRC) signaling, downlink control information (DCI) scheduling with explicit indication, or a timer for the UE to switch its active DL BWP to the default DL BWP. The BWP switching delay includes the RF setting update for the bandwidth and frequency position changes of all activated cells. When the switching delays of multiple active BWP switching overlap across multiple cells in the time domain, the switching delay of an earlier active BWP switching in one cell may be extended due to a later active BWP switching in another cell.

[0008] The UE behavior during the transition time of DCI-based or timer-based active BWP switching in BWP operation under carrier aggregation needs to be defined to avoid longer switching delays. Summary of the Invention

[0009] The present invention provides a method and user equipment for supporting active BWP switching under carrier aggregation. To avoid longer switching delays and multiple interruptions in other component carriers (CCs) / cells, the start time of a later active BWP switching in one cell should fall outside the switching delay of an earlier active BWP switching in another cell. If the later active BWP switching is based on DCI, the network should schedule the later active BWP switching outside the switching delay of the earlier active BWP switching. If the later active BWP switching is based on a timer, the UE should not perform the later active BWP switching until the earlier active BWP switching is completed.

[0010] In one embodiment, a UE receives configuration information sent from a base station in a wireless communication network. The UE operates on multiple CCs under carrier aggregation, and the UE is configured with multiple BWPs in each CC. When a first BWP switching triggering condition is satisfied, the UE performs a first active BWP switching in the first CC. The UE detects that a second BWP switching triggering condition is satisfied that triggers a second active BWP switching in a second CC. The UE determines a duration for the first active BWP switching in the first CC, and when the second BWP switching is triggered during the duration, the UE avoids performing the second active BWP switching.

[0011] Other embodiments and advantages are described in the detailed description that follows. This summary is not intended to define the invention. The invention is defined by the claims. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1 A wireless communication system supporting active BWP switching in carrier aggregation according to novel aspects is illustrated.

[0013] Figure 2 is a simplified block diagram of a wireless transmitting device and a receiving device in accordance with novel aspects.

[0014] Figure 3 Multiple active BWP switches on different CCs having different BWP switch delays and causing outage times in other CCs in a wireless communication system are shown.

[0015] Figure 4 It is shown that the DCI-based active BWP switching first occurs in the cell with smaller subcarrier spacing (SCS) in the carrier aggregation.

[0016] Figure 5 It is shown that the DCI-based active BWP switching occurs first in the cell with the larger SCS in the carrier aggregation.

[0017] Figure 6 The sequence flow between the base station and the user equipment is shown to avoid the longer BWP switching delay and interruption time caused by DCI-based BWP switching under CA.

[0018] Figure 7 The sequence flow between the base station and the user equipment is shown to avoid the longer BWP switching delay and interruption time caused by the timer-based BWP switching under CA.

[0019] Figure 8 is a flow chart of a method for avoiding longer BWP switching delay and interruption time under CA according to one novel aspect. DETAILED DESCRIPTION

[0020] Reference will now be made in detail to some embodiments of the present invention, examples of which are illustrated in the accompanying drawings.

[0021] Figure 1A wireless communication system supporting active BWP switching according to novel aspects is shown, which avoids long switching delays and interruption times in CA. A 5G NR mobile communication network 100 includes a base station BS / gNB 101 and a user equipment UE 102. When there is a downlink packet to be sent from a gNodeB to a UE, each UE obtains a downlink allocation, for example, a set of radio resources in a physical downlink shared channel (PDSCH). When a UE needs to send a packet to a gNodeB in the uplink, the UE obtains a grant from the gNodeB that allocates a physical uplink shared channel (PUSCH) consisting of a set of uplink radio resources. The UE obtains downlink or uplink scheduling information from a physical downlink control channel (PDCCH) specifically for the UE. In addition, broadcast control information is also sent to all UEs in the cell in the PDCCH. The downlink or uplink scheduling information and broadcast control information carried by the PDCCH are called downlink control information (DCI). If the UE has data or RRC signaling, uplink control information (UCI) including HARQ ACK / NACK, CQI, MIMO feedback, and scheduling request is carried by the physical uplink control channel (PUCCH) or PUSCH.

[0022] To conserve UE power consumption, multiplex UEs using different bandwidths or parameter sets (e.g., cyclic prefix and subcarrier spacing), and achieve active spectrum utilization over wide bandwidths, 5G NR introduces the concept of Bandwidth Workloads (BWPs). Use cases for BWP operation include: 1) enabling reduced UE bandwidth capabilities in wideband carriers; 2) reducing UE power consumption through bandwidth adaptation; and 3) enabling UEs to use different parameter sets in FDM within wideband carriers. For each UE-specific serving cell corresponding to a CC and gNB, one or more DL BWPs and one or more UL BWPs can be configured via the UE's dedicated RRC. Under Carrier-Based Carrier (CA), each UE in each serving cell can be configured with several DL BWPs and UL BWPs by the network. A UE is required to use at most one DL (or UL) BWP for radio signal reception (or transmission) at a given time for a serving cell, unless the serving cell is configured with a supplemental uplink (SUL). In this exceptional case, the UE is required to use at most one UL BWP for radio signal transmission on each UL carrier. The DL BWP (or UL BWP) that a UE is using for radio signal reception (or transmission) is called the active DL (or UL) BWP. For each UE, a serving cell has at most one active DL (or UL) BWP at a given time, unless the serving cell is configured with a SUL, in which case the UE is required to use at most one UL BWP for radio signal transmission on each UL carrier. The UE will use the initial active DL (or UL) BWP for radio signal reception (or transmission) on the serving cell until a BWP is explicitly (re)configured for the UE during or after RRC connection establishment and the RRC connection is instructed to switch to one of the configured (or reconfigured) DL (or UL) BWPs. As a result, power consumption for monitoring the downlink can be reduced because the UE only needs to monitor a smaller frequency range of the active DL BWP.

[0023] A BWP consists of a continuous range of PRBs in the frequency domain, and the bandwidth occupied by the continuous range of PRBs is a subset of the bandwidth of the associated carrier. That is, the bandwidth of the BWP in a carrier is a subset of the carrier bandwidth, and the bandwidth size ranges from the synchronization signal (SS) block bandwidth to the maximum bandwidth capability supported by the UE in the component carrier. A BWP may or may not contain SS blocks. Reserved resources can be configured in the BWP. For UEs in connected mode, one or more BWP configurations for each component carrier can be semi-statically sent to the UE, and the configuration parameters include at least: parameter set (i.e., CP type, subcarrier spacing); frequency position based on the common PRB index of a given parameter set (the offset between the BWP and the reference point is implicitly or explicitly indicated to the UE); bandwidth size (in the form of PRBs); Control Resource Set (CORESET) (for a given moment, each BWP configuration is required in the case of a single active DL BWP).

[0024] For active BWP operation, the UE is only assumed to receive or transmit in an active BWP using the relevant parameter set – at least PDSCH and PDCCH for DL, and PUCCH and PUSCH for UL. The UE expects that at a given moment in time, at least one DL BWP and UL BWP from the set of configured BWPs is active. In the case of a single active DL BWP at a given moment in time in a component carrier, the UE may assume that the PDSCH and the corresponding PDCCH are transmitted within the same BWP if the PDSCH transmission starts no later than K symbols after the end of the PDCCH transmission. In the case where the PDSCH transmission starts more than K symbols after the end of the corresponding PDCCH, the PDCCH and PDSCH may be transmitted in different BWPs. Activation / deactivation of a BWP can be accomplished via dedicated RRC signaling, via DCI scheduling with an explicit indication, or via a timer used by the UE to switch the active DL BWP to a default DL BWP (e.g., the initial active DL BWP).

[0025] If the handover delays for more than one Active BWP handover in the same CC / cell overlap in the time domain, the handover delay of the earlier Active BWP handover may be extended due to the later Active BWP handover. This is because the UE follows the latest Active BWP handover indication and reprocesses all relevant settings for the Active BWP handover. There are three types of Active BWP handovers: DCI-based DL, DCI-based UL, and timer-based. If the BWP inactivity timer for a cell is configured to be shorter than the handover delay of the earlier Active BWP handover, this will result in an extended handover delay for the earlier Active BWP handover due to the later Active BWP handover. Therefore, to address this issue, the UE can restart the BWP inactivity timer if it expires within the handover delay of the earlier Active BWP handover.

[0026] Under carrier aggregation, if the handover delays of more than one active BWP handover involving bandwidth and frequency location changes overlap across CCs / cells in the time domain, the handover delay of an earlier active BWP handover in one cell may be extended due to the following reasons: the reprocessing of the UE's RF setting update is triggered by a later active BWP handover in another cell, because the processing of the RF setting update of an active BWP handover involving bandwidth and frequency location changes must consider the RF settings of all activated CCs / cells. It can be observed that if the start time of a later active BWP handover in one cell falls within the handover delay of an earlier active BWP handover in another cell, it can introduce a handover delay of the earlier active BWP handover that is longer than the time offset indicated in the active BWP handover DCI, or can cause multiple interruptions in other cells within a short period of time.

[0027] According to one novel aspect, to avoid longer handover delays and interruptions, the start time of a later active BWP handover (e.g., on CC#2) should fall outside the handover delay of an earlier active BWP handover (e.g., on CC#1). If the later active BWP handover is based on DCI, the network should schedule the later active BWP handover on CC#2 outside the handover delay of the earlier active BWP handover on CC#1. If the later active BWP handover is timer-based, the UE should not perform the later active BWP handover on CC#2 until the earlier active BWP handover on CC#1 is completed.

[0028] Figure 22 is a simplified block diagram of wireless device 201 and wireless device 211 according to novel aspects. For wireless device 201 (e.g., a base station), antenna 207 and antenna 208 transmit and receive radio signals. RF transceiver 206, coupled to the antenna, receives RF signals from the antenna, converts them to baseband signals, and transmits them to processor 203. RF transceiver 206 also converts baseband signals received from the processor, converts them to RF signals, and transmits them to antenna 207 and antenna 208. Processor 203 processes the received baseband signals and invokes various functional modules and circuits to perform functions within wireless device 201. Memory 202 stores program instructions and data 210 to control the operation of device 201, where memory 202 may be a non-volatile computer-readable storage medium such as a read-only memory or a random access memory.

[0029] Similarly, for wireless device 211 (e.g., user equipment), antenna 217 and antenna 218 transmit and receive RF signals. RF transceiver 216, coupled to the antennas, receives RF signals from the antennas, converts them to baseband signals, and transmits them to processor 213. RF transceiver 216 also converts baseband signals received from the processor, converts them to RF signals, and transmits them to antennas 217 and 218. Processor 213 processes the received baseband signals and invokes various functional modules and circuits to execute functions within wireless device 211. Memory 212 stores program instructions and data 220 to control the operation of wireless device 211.

[0030] Wireless device 201 and wireless device 211 also include several functional modules and circuits that can be implemented and configured to perform embodiments of the present invention. Figure 2 In the example of FIG, wireless device 201 is a base station including CA and BWP configuration circuitry 205, scheduler 204, beamforming circuitry 209, and control circuitry 221. Wireless device 211 is a user equipment including CA processing circuitry 215, BWP processing circuitry 214, beamforming circuitry 219, and CA / BWP configuration and control circuitry 231. The various functional modules and circuits may be implemented and configured using software, firmware, hardware, or any combination thereof. When executed by processors 203 and 213 (e.g., by executing program instructions and data 210 and program instructions and data 220), the functional modules and circuits enable BS 201 and UE 211 to perform embodiments of the present invention, respectively.

[0031] In one example, BS 201 provides UE 211 with CA and BWP configurations for CA / BWP activation and switching via CA and BWP configuration circuitry 205. BS 201 schedules control and data transmissions via scheduler 204. BS 201 performs beamforming for directional communication via beamforming circuitry 209 and provides other control information to UE 211 via control circuitry 221. UE 211 performs carrier aggregation functions via CA processing circuitry 215, BWP functions via BWP processing circuitry 214, and beamforming for directional communication via beamforming circuitry 219. UE 211 processes CA and BWP configurations for CA / BWP activation and switching via configuration and control circuitry 231. UE 211 determines whether to perform a later scheduled active BWP switch in one cell based on whether this BWP switch would result in longer switching delays and multiple interruptions for an earlier scheduled active BWP switch in another cell, and whether the earlier active BWP switch in the other cell has completed.

[0032] Figure 3 The present invention shows multiple active BWP switching on different CCs with different BWP switching delays and causing interruption time in other CCs in a wireless communication system. Under carrier aggregation, if the switching delays of more than one active BWP switching involving bandwidth and frequency position changes overlap across CCs / cells in the time domain, the switching delay of an earlier active BWP switching in one cell may be extended due to a later active BWP switching in another cell triggering a reprocessing of the RF setting update by the UE, because the processing of the RF setting update of the active BWP switching involving bandwidth and frequency position changes must consider the RF settings of all activated cells. Figure 3 In the example of FIG, two active BWP switchings in different cells (eg, CC#1 and CC#2) are initiated, and it is assumed that the interruption in the other cell is within the minimum active BWP switching delay defined in 3GPP specification TS38.101.

[0033] exist Figure 3In Cases 1, 2, 3, and 4, the start time of a later Active BWP handover in one cell (CC#2) falls within the handover delay of an earlier Active BWP handover in another cell (CC#1). Consequently, for Cases 1 and 2, the later Active BWP handover in CC#2 introduces a longer delay than the earlier Active BWP handover indicated in the Active BWP handover DCI, as indicated by the extended handover delay for CC#1. For Cases 1, 2, 3, and 4, the later Active BWP handover in CC#2 introduces multiple outages in other cells within a short period of time, as indicated by the outage times for CC#1, CC#2, and CC#3. Therefore, it is observed that the start time of a later Active BWP handover in CC#2 should not fall within the handover delay of an earlier Active BWP handover in CC#1.

[0034] exist Figure 3 In cases 5 and 6, the start times of the two active BWP handovers are aligned with each other, so there is no need to extend the handover time and the outages in other cells can also be aligned. Therefore, it is best to exclude Figure 3 Cases 1, 2, 3 and 4 are to avoid handover delays longer than the time offset indicated in the active BWP handover DCI and to avoid multiple outages in a short period of time in other cells. In general, there are two possible ways to exclude Figure 3 Cases 1, 2, 3 and 4: 1) define the UE behavior to avoid this situation; 2) define this situation as an error situation that the network should avoid.

[0035] Figure 4 It is shown that the active BWP switching based on DCI occurs first in the cell with smaller SCS in the carrier aggregation. Figure 4 In the example shown in Figure 2, the UE is configured with three different cells: Cell 0 using 15KHz SCS, Cell 1 using 30KHz SCS, and Cell 2 using 60KHz SCS. Figure 4 (a) in Figure 1: The three cells are completely synchronized. Figure 4(b) in Figure 1: The three cells are not fully synchronized. The first active BWP switch is triggered in cell 0. During the active BWP switch time in cell 0 (e.g., the switch delay from time t1 to time t2), later active BWP switches are not allowed in cells 1 and 2. Note that the first active BWP switch is triggered by the DCI in the PDCCH on cell 0. During the switch delay, the UE is not required to transmit or receive data in cell 0 from the time slot in which the UE receives the PDCCH containing the DCI in cell 0 until the start of the time slot indicated by the time slot offset value in the time domain resource allocation field in the DCI. As a result, if the start time falls within the active BWP switch time of cell 0, a later active BWP switch is not allowed to start for cell 1 or cell 2. However, for cells 1 and 2, active BWP switches can start simultaneously in the first time slot of a set of time slots that overlap with the active BWP switch time of cell 0. This way, the start times of the active BWP switches can be aligned with each other, eliminating extended switch delays and different interruptions in other cells.

[0036] Figure 5 It is shown that the active BWP switching based on DCI occurs first in the cell with larger SCS in the carrier aggregation. Figure 5 In the example shown in Figure 2, the UE is configured with three different cells: Cell 0 using 15KHz SCS, Cell 1 using 30KHz SCS, and Cell 2 using 60KHz SCS. Figure 5 (a) in Figure 1: The three cells are completely synchronized. Figure 5 (b) in Figure 1: The three cells are not fully synchronized. The first active BWP switch is triggered in cell 2. During the active BWP switch time in cell 2 (e.g., the switch delay from time t1 to time t2), later active BWP switches are not allowed in cell 0 and cell 1. Note that the first active BWP switch is triggered by a DCI in the PDCCH on cell 2. During the switch delay, the UE is not required to transmit or receive data in cell 2 from the time slot in which the UE receives the PDCCH containing the DCI in cell 2 until the start of the time slot indicated by the slot offset value in the time domain resource allocation field in the DCI. As a result, if the start time falls within the active BWP switch time in cell 2, a later active BWP switch is not allowed to start for cell 0 or cell 1. However, for cell 0 and cell 1, active BWP switches can start simultaneously in the first slot of a set of slots that overlap with the active BWP switch time in cell 2. This way, the start times of the active BWP switches can be aligned, eliminating extended switch delays and different interruptions in other cells.

[0037] Figure 6The sequence flow between the base station and the user equipment is shown to avoid the longer BWP switching delay and interruption time caused by DCI-based BWP switching under CA. In step 611, UE 602 receives a configuration from gNB 601, for example, from a physical broadcast channel (PBCH / SIB1). UE 602 is configured with CA, and each CC is configured with multiple DL BWPs and UL BWPs, and UE 602 operates in an active DLBWP and an active UL BWP. In step 612, UE 602 detects a first active BWP switching trigger for a first cell (CC1). For example, UE 602 detects DCI format 1_1 or DCI format 0_1 ​​on a PDCCH indicating an active DLBWP change or an active UL BWP change for CC1. Optionally, UE 602 detects expiration of a BWP inactivity timer for the first cell (CC1). As a result, in step 613, UE 602 performs an active BWP switching and changes to another active BWP in CC1. UE 602 requires a BWP switching delay to perform an active BWP change, during which time the UE is not required to perform an active BWP switching. 602 transmits or receives data via CC1. Note that for DCI-based BWP switching, the DCI (same or cross-carrier scheduling) can be in the same or a different CC where the BWP switching occurs. Furthermore, the duration of the handover delay is indicated in the DCI and includes the minimum BWP handover delay required by the UE plus additional handover delay due to gNB limitations (e.g., DL / UL configuration in the TDD carrier, gNB processing time for scheduled data, gNB scheduling algorithm decisions).

[0038] As previously mentioned, to avoid long BWP switching delays in CC1 and multiple interruptions in other cells, the UE should not be scheduled during an earlier active BWP switch in CC1 during another later active BWP switch in another cell. In other words, it is undesirable for UE 602 to receive DCI format 1_1 or DCI format 0_1 ​​on a PDCCH indicating a scheduled active BWP change for the second cell (CC2) in a slot other than the first slot in a set of CC2 slots, which overlaps with a duration during which UE 602 is not required to receive or transmit an active BWP change in the first cell (CC1). While it is undesirable for UE 602 to detect such DCI, the reason for this is that the network should not be assumed to avoid a later scheduled BWP change. Nevertheless, if UE 602 does detect such DCI in step 621, then in step 622, UE 602 either ignores the DCI or discards it as an error.

[0039] Figure 7The sequence flow between the base station and user equipment is shown to avoid the longer BWP switching delays and interruption times caused by timer-based BWP switching under carrier aggregation (CA). In step 711, UE 702 receives a configuration from gNB 701, for example, from PBCH / SIB1. UE 702 is configured with CA, and each CC is configured with multiple DL BWPs and UL BWPs, and UE 702 operates with both an active DL BWP and an active UL BWP. In step 712, UE 702 detects a first active BWP switching trigger for a first cell (CC1). For example, UE 702 detects DCI format 1_1 or DCI format 0_1 ​​on the PDCCH indicating an active DL BWP change or an active UL BWP change for CC1. Optionally, UE 702 detects expiration of the BWP inactivity timer for the first cell (CC1). Consequently, in step 713, UE 702 performs an active BWP switching and changes to another active BWP in CC1. The UE 702 requires a BWP switching delay for the active BWP to change, during which time the UE 702 is not required to transmit or receive data over CC1.

[0040] In step 721, UE 702 detects the expiration of the BWP inactivity timer for the second cell (CC2). This expiration would trigger another active BWP handover in CC2. However, because the timer expires during the handover time of the earlier active BWP handover in CC1, UE 702 delays the timer-based active BWP handover in CC2 until the earlier active BWP handover in CC1 completes. In step 722, UE 702 determines whether the active BWP handover in CC1 is complete. If not, UE 702 does nothing. If so, UE 702 performs an active BWP handover in CC2. By introducing additional conditions for timer-based active BWP handover, UE 702 ensures that the later active BWP handover does not cause a longer handover delay than the earlier active BWP handover or cause more disruption to other cells.

[0041] Figure 8This invention is a flow chart of a method for avoiding longer BWP switching delays and interruption times under carrier aggregation (CA) according to one novel aspect. In step 801, a UE receives configuration information transmitted from a base station in a wireless communication network. The UE operates on multiple CCs under carrier aggregation, and the UE is configured with multiple BWPs in each CC. In step 802, when a first BWP switching triggering condition is satisfied, the UE performs a first active BWP switching in the first CC. In step 803, the UE detects that a second BWP switching triggering condition is satisfied for triggering a second active BWP switching in a second CC. In step 804, the UE determines a duration of the first active BWP switching in the first CC, wherein if a second BWP switching is triggered within the duration, the UE is prohibited from performing the second active BWP switching.

[0042] Although the present invention has been described in conjunction with certain specific embodiments for guiding purposes, it is not limited thereto. Therefore, various modifications, adaptations and combinations of the various features of the described embodiments may be made without departing from the scope of the invention as set forth in the claims.

Claims

1. A method for switching active bandwidth portions in carrier aggregation, comprising: Receiving, by a user equipment in a wireless communication network, configuration information sent from a base station, wherein the user equipment operates on a plurality of component carriers under carrier aggregation, and wherein the user equipment is configured with a plurality of bandwidth parts in each component carrier; When a first bandwidth part switching triggering condition is met, the user equipment performs a first active bandwidth part switching in the first component carrier; detecting that a second bandwidth part switching triggering condition for triggering a second active bandwidth part switching in a second component carrier is satisfied, wherein the second bandwidth part switching triggering condition is satisfied by receiving downlink control information in a time slot indicating the second active bandwidth part switching of the second component carrier; and determining whether to trigger the second active bandwidth portion switch within a duration of a switch delay of the first active bandwidth portion switch, wherein when the timeslot overlaps with the duration, the user equipment ignores the downlink control information and abandons performing the second active bandwidth portion switch in the second component carrier.

2. The method according to claim 1, characterized in that The first bandwidth part switching triggering condition is satisfied by receiving second downlink control information indicating switching of the first active bandwidth part of the first component carrier.

3. The method according to claim 1, characterized in that The first bandwidth part switching triggering condition is satisfied by detecting expiration of the first bandwidth part inactivity timer of the first component carrier.

4. The method according to claim 1, wherein If the time slot is a first time slot in a set of time slots overlapping with the time duration, the user equipment performs the second active bandwidth portion switching.

5. The method according to claim 1, wherein The duration determined in the downlink control information indicating active bandwidth part switching comprises a minimum bandwidth part switching delay required by the user equipment plus an additional switching delay due to scheduling restrictions of the base station.

6. The method according to claim 1, characterized in that The user equipment does not need to transmit or receive data via the first component carrier during the handover delay.

7. A user equipment for switching active bandwidth portions in carrier aggregation, comprising: a receiver configured to receive configuration information sent by a base station in a wireless communication network, wherein the user equipment operates on multiple component carriers under carrier aggregation, and wherein the user equipment is configured with multiple bandwidth parts in each component carrier; a bandwidth part processing circuit, configured to, when a first bandwidth part switching triggering condition is met, cause the user equipment to perform a first active bandwidth part switching in the first component carrier; and a control circuit to detect that a second bandwidth portion switching triggering condition for triggering a second active bandwidth portion switching in a second component carrier is satisfied, wherein the second bandwidth portion switching triggering condition is satisfied by receiving downlink control information in a time slot for indicating the second active bandwidth portion switching of the second component carrier, wherein when the time slot overlaps with a duration of a switching delay for the first active bandwidth portion switching in the first component carrier, the user equipment ignores the downlink control information and abandons performing the second active bandwidth portion switching in the second component carrier.

8. The user equipment according to claim 7, wherein: The first bandwidth part switching triggering condition is satisfied by receiving second downlink control information indicating switching of the first active bandwidth part of the first component carrier.

9. The user equipment according to claim 7, wherein: The first bandwidth part switching triggering condition is satisfied by detecting expiration of the first bandwidth part inactivity timer for the first component carrier.

10. The user equipment according to claim 7, wherein: If the time slot is a first time slot in a set of time slots overlapping with the time duration, the user equipment performs the second active bandwidth portion switching.

11. The user equipment according to claim 7, wherein: The duration determined in the downlink control information indicating active bandwidth part switching comprises a minimum bandwidth part switching delay required by the user equipment plus an additional switching delay due to scheduling restrictions of the base station.

12. The user equipment according to claim 7, wherein: The user equipment does not need to transmit or receive data via the first component carrier during the handover delay.

13. A method for switching active bandwidth portions in carrier aggregation, comprising: Receiving, by a user equipment in a wireless communication network, configuration information sent from a base station, wherein the user equipment operates on a plurality of component carriers under carrier aggregation, and wherein the user equipment is configured with a plurality of bandwidth parts in each component carrier; When a first bandwidth part switching triggering condition is met, the user equipment performs a first active bandwidth part switching in the first component carrier; detecting satisfaction of a second bandwidth portion switching triggering condition for triggering switching of a second active bandwidth portion in a second component carrier, wherein the second bandwidth portion switching triggering condition is satisfied by detecting expiration of a bandwidth portion inactivity timer of the second component carrier; as well as Determining whether the inactivity timer expires within a duration of a switch delay of the first active bandwidth portion switch, wherein the user equipment delays the second active bandwidth portion switch until the first active bandwidth portion switch is complete.

14. The method according to claim 13, characterized in that The first bandwidth part switching triggering condition is satisfied by receiving downlink control information indicating switching of the first active bandwidth part of the first component carrier.

15. The method according to claim 13, characterized in that The first bandwidth part switching triggering condition is satisfied by detecting that a bandwidth part inactivity timer of the first component carrier has expired.

16. The method according to claim 13, characterized in that The duration determined in the downlink control information indicating active bandwidth part switching comprises a minimum bandwidth part switching delay required by the user equipment plus an additional switching delay due to scheduling restrictions of the base station.

17. The method according to claim 13, wherein The user equipment does not need to transmit or receive data via the first component carrier during the handover delay.

18. A user equipment for switching active bandwidth portions in carrier aggregation, comprising: A processor is coupled to the memory and the transceiver, and when the processor executes the program instructions and data stored in the memory, the user equipment performs the operation described in any one of the methods of claims 1-6 and 13-17 above.

19. A non-volatile computer-readable storage medium storing program instructions and data, which, when executed by a processor of a user equipment for switching active bandwidth portions in carrier aggregation, causes the user equipment to perform the operations described in any one of claims 1-6 and 13-17 above.

Images