Method and user equipment for wireless communication

Abstract

The present application can provide a method and UE for cross-carrier scheduling from a secondary cell to a primary cell. In particular, a UE can be connected to a primary cell and a secondary cell, wherein cross-carrier scheduling is configured between the primary cell and the secondary cell. According to the type of the UE, when the UE is a first type UE, the UE can monitor PDCCH from both the primary cell and the secondary cell in the same time slot, or when the UE is a second type UE, the UE can ignore PDCCH from the secondary cell in the same time slot. By utilizing the present application, wireless communication can be better.

Description

TECHNICAL FIELD

[0001] The present disclosure relates to wireless communications, and more particularly, to a method and apparatus for cross-carrier scheduling (CCS) from a secondary cell (SCell) to a primary cell (PCell). BACKGROUND

[0002] In a conventional Third Generation Partnership Project (3GPP) Fifth Generation (5G) New Radio (NR) network, as the number of NR devices in the network increases, there can not be enough NR Physical Downlink Control Channel (PDCCH) scheduling resources on an NR PCell in a shared carrier. Therefore, cross-carrier scheduling by a corresponding SCell to schedule the PCell is developed. However, details of the procedure of scheduling the PCell by the corresponding SCell have not been discussed. rd Generation Partnership Project,3GPP) Fifth Generation (5 th Generation,5G) New Radio (NR) network, as the number of NR devices in the network increases, there can not be enough NR Physical Downlink Control Channel (PDCCH) scheduling resources on an NR PCell in a shared carrier. Therefore, cross-carrier scheduling by a corresponding SCell to schedule the PCell is developed. However, details of the procedure of scheduling the PCell by the corresponding SCell have not been discussed. SUMMARY

[0003] The present disclosure can provide a method and a UE for cross-carrier scheduling from a secondary cell to a primary cell. In particular, the UE can be connected to a primary cell and a secondary cell, wherein cross-carrier scheduling can be configured between the primary cell and the secondary cell. According to the type of the UE, when the UE is a first type of UE, the UE can monitor PDCCH from both the primary cell and the secondary cell in the same time slot, or when the UE is a second type of UE, the UE can ignore PDCCH from the secondary cell in the same time slot.

[0004] A method for wireless communication includes connecting, by a user equipment, to a primary cell and a secondary cell, wherein cross-carrier scheduling is configured between the primary cell and the secondary cell, and monitoring, by the user equipment, a physical downlink control channel from both the primary cell and the secondary cell in a same time slot when the user equipment is a first type of user equipment, or ignoring, by the user equipment, the physical downlink control channel from the secondary cell in the same time slot when the user equipment is a second type of user equipment.

[0005] A user equipment for wireless communication, comprising: a transceiver connected to a primary cell and a secondary cell, wherein cross-carrier scheduling is configured between the primary cell and the secondary cell; and a scheduling circuitry configured to monitor a physical downlink control channel from both the primary cell and the secondary cell in a same time slot when the user equipment is a first type of user equipment, or to ignore the physical downlink control channel from the secondary cell in the same time slot when the user equipment is a second type of user equipment.

[0006] By utilizing the present application, wireless communication can be better performed.

[0007] Other embodiments and advantages will be described in the following detailed description of the application. This summary is not intended to define the application. The application is defined by the claims. BRIEF DESCRIPTION OF DRAWINGS

[0008] The accompanying drawings, which are incorporated herein by reference, can illustrate the embodiments of the application, wherein like numberings can represent like components.

[0009] Figure 1 An exemplary 5G NR network supporting cross-carrier scheduling from a secondary cell to a primary cell according to embodiments of the application can be illustrated. The base stations (BSs) of the two cells can be co-located or non-co-located.

[0010] Figure 2 A simplified block diagram of a cell and a UE according to embodiments of the application can be illustrated.

[0011] Figure 3 An exemplary cell time slot according to embodiments of the application can be illustrated.

[0012] Figure 4 An exemplary cell time slot according to embodiments of the application can be illustrated.

[0013] Figure 5 An exemplary cell time slot according to embodiments of the application can be illustrated.

[0014] Figure 6 A flowchart of a method for cross-carrier scheduling from a secondary cell to a primary cell according to embodiments of the application can be illustrated. DETAILED DESCRIPTION

[0015] Reference will now be made in detail to some embodiments of the application, examples of which are illustrated in the accompanying drawings.

[0016] Figure 1An exemplary 5G NR network 100 that supports cross-carrier scheduling from a secondary cell to a primary cell according to embodiments of the present application can be illustrated. The 5G NR network 100 can include a user equipment (UE) 110 communicably connected to a primary cell 121 and a secondary cell 123, where the primary cell 121 can be served by a base station 120 and the secondary cell 123 can be served by a base station 130. Note that the primary cell 121 can include a general primary cell or a primary cell of a secondary cell group (i.e., PSCell). In some embodiments, the base station 120 of the primary cell 121 and the base station 130 of the secondary cell 123 can be co-located or non-co-located.

[0017] The primary cell 121 and the secondary cell 123 can provide radio access using a radio access technology (RAT), such as a 5G NR technology. The UE 110 can be a smartphone, a wearable device, an Internet of Things (IoT) device, a tablet, and the like. Alternatively, the UE 110 can be a notebook (NB) or a personal computer (PC) into which a data card is inserted or installed, where the data card can include a modem and a radio frequency (RF) transceiver to provide a wireless communication function.

[0018] The primary cell 121 can provide communication coverage for a geographic coverage area in which communication with the UE 110 can be supported through communication link 101. The secondary cell 123 can provide communication coverage for a geographic coverage area in which communication with the UE 110 can be supported via communication link 103. The communication links 101 and 103 shown in the 5G NR network 100 can each include uplink (UL) transmissions, e.g., on a physical uplink control channel (PUCCH) or on a physical uplink shared channel (PUSCH), from a UE 110 to the cell 121 / 123, or downlink (DL) transmissions, e.g., on a physical downlink control channel (PDCCH) or on a physical downlink shared channel (PDSCH), from the cell 121 / 123 to the UE 110. The primary cell 121 and the secondary cell 123 can communicate with each other through communication link 122.

[0019] In the network 100, cross-carrier scheduling from the secondary cell 123 to the primary cell can be configured. In particular, when cross-carrier scheduling from the secondary cell 123 to the primary cell 121 is configured, some PDCCH of the primary cell 121 can be reassigned to the secondary cell 123. In other words, the PDCCH allocated on the secondary cell 123 can exert control over the primary cell 121.

[0020] Figure 2 A simplified block diagram of the primary cell 121 / secondary cell 123 (primary cell 121 or secondary cell 123) and the UE 110 according to embodiments of the present application can be illustrated. The primary cell 121 / secondary cell 123 can have an antenna 197 to transmit and receive radio signals. An RF transceiver module 196 is coupled with the antenna, can receive RF signals from the antenna, convert the RF signals to baseband signals, and send the baseband signals to the processor 193. The RF transceiver module 196 also converts baseband signals received from the processor to RF signals and sends the RF signals to the antenna 197. The processor 193 processes the received baseband signals and invokes different functional modules and circuits to perform features in the primary cell 121 / secondary cell 123. The storage medium 192 can store program instructions and data 190 to control the operation of the primary cell 121 / secondary cell 123.

[0021] Similarly, for the UE 110, the antenna 177 can transmit and receive RF signals. The RF transceiver module 176, coupled with the antenna, can receive RF signals from the antenna, convert the RF signals to baseband signals, and send the baseband signals to the processor 173. The RF transceiver module 176 can also convert baseband signals received from the processor to RF signals and send the RF signals to the antenna 177. The processor 173 processes the received baseband signals and invokes different functional modules and circuits to perform features in the UE 110. The storage medium 172 can store program instructions and data 170 to control the operation of the UE 110.

[0022] The primary cell 121 / secondary cell 123 and the UE 110 can also include some functional modules and circuits that can be implemented and configured to perform embodiments of the present application. In the example of the primary cell 121 / secondary cell 123, the primary cell 121 / secondary cell 123 can include a set of control functional modules and circuits 180. The scheduling circuit 182 can handle cross-carrier scheduling from the secondary cell 123 to the primary cell 121 and related network parameters for the UE 110. The configuration and control circuit 181 can provide different parameters to configure and control the UE 110. The UE 110 can include a set of control functional modules and circuits 160. The scheduling circuit 162 can handle cross-carrier scheduling from the secondary cell 123 to the primary cell 121 and related network parameters. The configuration and control circuit 161 can handle configuration and control parameters from the primary cell 121 / secondary cell 123. Figure 2

[0023] Please note that different functional modules and circuits can be implemented and configured by software, firmware, hardware, and any combination thereof. The above functional modules and circuits, when executed by the processors 193 and 173 (e.g., by executing program codes 190 and 170), can allow the primary cell 121 / secondary cell 123 and the UE 110 to perform embodiments of the present application.

[0024] In some embodiments, the UE 110 can: (1) monitor PDCCH from both the primary cell 121 and the secondary cell 123 in the same time slot when the UE 110 is a first type of UE (e.g., an advanced UE that supports cross-carrier scheduling from the secondary cell to the primary cell); or (2) ignore PDCCH from the secondary cell 123 in the same time slot when the UE 110 is a second type of UE (e.g., a legacy UE that does not support cross-carrier scheduling from the secondary cell to the primary cell).

[0025] Figure 3 ​An exemplary cell slot according to embodiments of the application can be illustrated. In this example, the SCS of the primary cell 121 can be 15 kHz, the SCS of the secondary cell 123 can be 30 kHz, and the UE 110 can be a second type UE. Because the UE 110 is a second type UE (e.g., a legacy UE), the UE 110 can not be able to monitor PDCCH from both the primary cell 121 and the secondary cell 123 in the same slot to schedule PDSCH of the primary cell 121. Thus, the UE 110 can only monitor PDCCH from the primary cell 121 for self-scheduling and ignore PDCCH from the secondary cell 123 for cross-carrier scheduling in the same slot (i.e., slot #0).

[0026] In some embodiments, at least one CSS set (e.g., Type 0 / 0A / 1 / 2 CSS set) on the primary cell 121 can be configured to overlap with at least one USS set for scheduling the primary cell 121 on the secondary cell 123, where the at least one USS set is used for scheduling the primary cell 121 on the secondary cell 123. The UE 110 can drop the at least one USS set for scheduling the primary cell 121 on the secondary cell 123.

[0027] Figure 4 An exemplary cell slot according to embodiments of the application can be illustrated. In this example, the SCS of the primary cell 121 can be 15 kHz, the SCS of the secondary cell 123 can be 30 kHz, and the UE 110 can be a first type UE. Because the UE 110 is a first type UE (e.g., an advanced UE supporting cross-carrier scheduling from the secondary cell to the primary cell), the UE 110 can be able to monitor PDCCH from both the primary cell 121 and the secondary cell 123 in the same slot to schedule PDSCH of the primary cell 121. Thus, the UE 110 can monitor PDCCH from the primary cell 121 for self-scheduling and monitor PDCCH from the secondary cell 123 for cross-carrier scheduling in the same slot (i.e., slot #0).

[0028] In particular, on the primary cell 121, the UE 110 can monitor at most a×X PDCCH blind detection candidates per PCell slot. On the secondary cell 123, the UE 110 can monitor at most β×X PDCCH blind detection candidates per PCell slot.

[0029] In some embodiments, a + b = 1. In some embodiments, a, b, or both can be configured in a Radio Resource Control (RRC) configuration transmitted from the primary cell 121 to the UE 110. For example, a can be configured to be between 0 and 1.

[0030] In some embodiments, X can be where m is the subcarrier spacing of the primary cell 121 (e.g., 15 kHz). is the maximum number of PDCCH candidates monitored in each slot on the primary cell 121. may be and is the number of cells the UE 110 can connect to, is the number of DL cells of subcarrier spacing j the UE 110 is configured with.

[0031] In some embodiments, a x X PDCCH blind detection candidates on the primary cell 121 can be configured for an overbooking procedure of PDCCH. In particular, the maximum number of PDCCH blind detection candidates for the overbooking procedure can not exceed a x X.

[0032] In some embodiments, at most a x X PDCCH blind detection candidates can be monitored. For example, for cross-carrier scheduling from the secondary cell 123 to the primary cell 121, the number of counted PDCCH candidates for monitoring the USS set S uss may be at most a x X.

[0033] Figure 5 An exemplary cell slot according to embodiments of the present application can be illustrated. In this example, the SCS of the primary cell 121 can be 15 kHz, the SCS of the secondary cell 123 can be 30 kHz, and the UE 110 can be a first type UE. Because the UE 110 is a first type UE (e.g., an advanced UE that supports cross-carrier scheduling from the secondary cell to the primary cell), the UE 110 can monitor PDCCH from both the primary cell 121 and the secondary cell 123 in the same slot of the primary cell 121. Thus, the UE 110 can monitor PDCCH from the primary cell 121 for self-scheduling and monitor PDCCH from the secondary cell 123 for cross-carrier scheduling in the same slot (i.e., slot #0). In embodiments of the present application, the UE 110 can monitor PDCCH from the secondary cell 123 for self-scheduling.

[0034] ​In particular, on the primary cell 121, the UE 110 can monitor up to aX PDCCH blind detection candidates per PCell slot. On the secondary cell 123, the UE 110: (1) can monitor up to Y PDCCH blind detection candidates per SCell slot; and (2) can monitor up to βχ PDCCH blind detection candidates per PCell slot. In some embodiments, a + β = 1.

[0035] In some embodiments, X can be where μ is the subcarrier spacing of the primary cell 121 (e.g., 15 kHz). is the maximum number of PDCCH candidates monitored per slot on the primary cell 121. may be While is the number of cells the UE 110 can connect to, is the number of DL cells of subcarrier spacing j that the UE 110 is configured with.

[0036] In some embodiments, Y can be or where μ1 is the subcarrier spacing of the secondary cell 123 (e.g., 30 kHz). is the maximum number of PDCCH candidates monitored per slot on the secondary cell 123. may be where is the number of cells the UE 110 can connect to, is the number of DL cells of subcarrier spacing j that the UE 110 is configured with.

[0037] In embodiments of the present application, the scaling of may be scaled by applying a second weight The sum of the first weight and the second weight can be 1. For example, the first weight can be 1 and the second weight can be 0.

[0038] Note that the above or may be defined as the following table of 3GPP specification:

[0039]

[0040]

[0041] In some embodiments, some downlink control information (DCI) of the PDCCH can be transmitted between the UE 110 and the primary cell 121. In particular, DCI format 2_5 (for integrated access and backhaul control) or DCI format 2_6 (wakeup signal, used outside active time) can be transmitted from the primary cell 121 to the UE 110. The UE can only receive / monitor the DCI format 2_5 or the DCI format 2_6 from the primary cell 121.

[0042] Figure 6 is a flowchart of a method for cross-carrier scheduling from a secondary cell to a primary cell from a UE perspective in a 5G / NR network according to embodiments of the present application. In step 601, the UE is connected to a primary cell and a secondary cell, wherein cross-carrier scheduling is configured between the primary cell and the secondary cell. In step 602, the UE monitors PDCCH from both the primary cell and the secondary cell in the same time slot when the UE is a first type of UE, or the UE ignores PDCCH from the secondary cell in the same time slot when the UE is a second type of UE. In some embodiments, the first type of UE can be an advanced UE that supports cross-carrier scheduling from the secondary cell to the primary cell, and the second type of UE can be a legacy UE that does not support cross-carrier scheduling from the secondary cell to the primary cell.

[0043] In some embodiments, when the UE is the second type of UE, at least one common search space set on the primary cell is configured to overlap with at least one USS set for scheduling the primary cell on the secondary cell, step 602 can further comprise: dropping, by the UE, the at least one USS set for scheduling the primary cell on the secondary cell.

[0044] In some embodiments, when the UE is the first type of UE, step 602 can further comprise: (1) monitoring at most a×X PDCCH blind detection candidates in each primary cell time slot on the primary cell; and (2) monitoring at most b×X PDCCH blind detection candidates in each primary cell time slot on the secondary cell,

[0045] In some embodiments, a + b = 1. In some embodiments, a, b, or both can be configured in RRC configuration transmitted from the primary cell 121 to the UE 110. For example, a can be configured to be between 0 and 1.

[0046] In some embodiments, X can be where μ is a first subcarrier spacing of the primary cell, is a maximum number of PDCCH candidates monitored in each time slot on the primary cell, and is where a number of cells that the UE can connect to, a number of downlink cells with subcarrier spacing j that the UE is configured with.

[0047] In some embodiments, a×X PDCCH blind detection candidates on the primary cell can be configured for the overbooking procedure of PDCCH. In particular, the maximum number of PDCCH blind detection candidates for the overbooking procedure can not exceed a×X.

[0048] In some embodiments, at most a×X PDCCH blind detection candidates can be monitored. For example, for cross-carrier scheduling from the secondary cell to the primary cell, the number of PDCCH candidates M for monitoring the USS set S uss may be at most a×X. Suss may be at most a×X.

[0049] In some embodiments, when the UE is a first type of UE, step 602 can further include monitoring at most Y PDCCH blind detection candidates in each secondary cell slot on the secondary cell.

[0050] In some embodiments, Y is or where μ1 is the subcarrier spacing of the secondary cell (e.g., 30 kHz). is the maximum number of PDCCH candidates monitored in each slot on the secondary cell, and may be where a number of cells that the UE can connect to, a number of downlink cells with subcarrier spacing j that the UE is configured with.

[0051] In some embodiments, the first weight can be applied to adjust and the second weight can be applied to adjust where the sum of the first weight and the second weight can be 1. For example, the first weight is 1 and the second weight is 0.

[0052] The present application is disclosed above with reference to specific embodiments for the purpose of guiding without limiting the present application. Accordingly, various features of the above-described embodiments can be modified, adjusted and combined without departing from the scope set forth in the claims of the present application.

Claims

1. A method for wireless communication, comprising: The user equipment connects to a primary cell and a secondary cell, wherein cross-carrier scheduling is configured between the primary cell and the secondary cell; as well as When the user equipment is a first type user equipment, the user equipment monitors the physical downlink control channels from both the primary cell and the secondary cell in the same time slot, or When the user equipment is a second type of user equipment, the user equipment ignores the physical downlink control channel from the secondary cell in the same time slot. Wherein, when the user equipment is the first type of user equipment, the step of monitoring the physical downlink control channel from both the primary cell and the secondary cell in the same time slot further includes: The user equipment monitors at most α×X physical downlink control channel blind detection candidates in each primary cell time slot of the primary cell; and The user equipment monitors a maximum of β×X physical downlink control channel blind detection candidates in each primary cell time slot of the secondary cell. Where α+β=1.

2. The method for wireless communication as described in claim 1, characterized in that, When the user equipment is the second type of user equipment, at least one common search space set on the primary cell is configured to overlap with at least one user equipment-specific search space set, the at least one user equipment-specific search space set being used to schedule the primary cell on the secondary cell, wherein the step of ignoring the physical downlink control channel from the secondary cell in the same time slot further includes: The user equipment discards at least one user equipment-specific search space set.

3. The method for wireless communication as described in claim 1, characterized in that, α is between 0 and 1 and is configured in the radio resource control configuration.

4. The method for wireless communication as described in claim 1, characterized in that, X is Where μ is the first subcarrier spacing of the main cell. The maximum number of physical downlink control channel candidates monitored in each time slot of the primary cell, and for in This refers to the number of cells that the user equipment can connect to. The number of downlink cells with a subcarrier spacing of j configured for the user equipment.

5. The method for wireless communication as described in claim 4, characterized in that, The α×X physical downlink control channel blind detection candidates on the primary cell are configured for over-prescribing processes.

6. The method for wireless communication as described in claim 4, characterized in that, The method further includes: the first subcarrier spacing μ of the primary cell is less than or equal to the second subcarrier spacing μ1 of the secondary cell; The user equipment monitors at most Y physical downlink control channel blind detection candidates in each secondary cell time slot of the secondary cell, where Y is... or The maximum number of physical downlink control channel candidates monitored in each time slot on the secondary cell, and for Among them, the first weight can be applied to Adjustments can be made by applying a second weight. The adjustment is made, wherein the sum of the first weight and the second weight is 1.

7. The method for wireless communication as described in claim 6, characterized in that, The first weight is 1, and the second weight is 0.

8. The method for wireless communication as described in claim 1, characterized in that, A maximum of α×X physical downlink control channel blind detection candidates can be monitored.

9. The method for wireless communication as described in claim 1, characterized in that, Receive downlink control information with downlink control information format 2_5 or downlink control information format 2_6 from the main cell.

10. A user equipment for wireless communication, comprising: A transceiver connected to a primary cell and a secondary cell, wherein cross-carrier scheduling is configured between the primary cell and the secondary cell; as well as The scheduling circuit, when the user equipment is a first type user equipment, monitors the physical downlink control channels from both the primary cell and the secondary cell in the same time slot, or When the user equipment is a second type of user equipment, the physical downlink control channel from the secondary cell is ignored in the same time slot. Wherein, when the user equipment is the first type of user equipment, the scheduling circuit further includes: In each primary cell time slot of the primary cell, a maximum of α×X physical downlink control channel blind detection candidates are monitored; and In each primary cell time slot on the secondary cell, a maximum of β×X physical downlink control channel blind detection candidates are monitored. Where α+β=1.

11. The user equipment as claimed in claim 10, characterized in that, When the user equipment is the second type of user equipment, at least one common search space set on the primary cell is configured to overlap with at least one user equipment-specific search space set, the at least one user equipment-specific search space set being used to schedule the primary cell on the secondary cell, and the scheduling circuit further: The user equipment discards at least one user equipment-specific search space set.

12. The user equipment as claimed in claim 10, characterized in that, α is between 0 and 1 and is configured in the radio resource control configuration.

13. The user equipment as claimed in claim 10, characterized in that, X is Where μ is the first subcarrier spacing of the main cell. The maximum number of physical downlink control channel candidates monitored in each time slot of the primary cell, and for in This refers to the number of cells that the user equipment can connect to. The number of downlink cells with a subcarrier spacing of j configured for the user equipment.

14. The user equipment as claimed in claim 13, characterized in that, The α×X physical downlink control channel blind detection candidates on the primary cell are configured for over-prescribing processes.

15. The user equipment as claimed in claim 13, characterized in that, The first subcarrier spacing μ of the primary cell is less than or equal to the second subcarrier spacing μ1 of the secondary cell, and the scheduling circuit further includes: In each secondary cell time slot of the secondary cell, a maximum of Y physical downlink control channel blind detection candidates are monitored, where Y is... or The maximum number of physical downlink control channel candidates monitored in each time slot on the secondary cell, and for Among them, the first weight can be applied to Adjustments can be made by applying a second weight. The adjustment is made, wherein the sum of the first weight and the second weight is 1.

16. The user equipment as claimed in claim 15, characterized in that, The first weight is 1, and the second weight is 0.

17. The user equipment as claimed in claim 10, characterized in that, A maximum of α×X physical downlink control channel blind detection candidates can be monitored.

18. The user equipment as claimed in claim 10, characterized in that, Receive downlink control information with downlink control information format 2_5 or downlink control information format 2_6 from the main cell.

19. A storage medium storing program instructions that, when executed by a user equipment, cause the user equipment to perform the steps of the method for wireless communication according to any one of claims 1-9.

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