CN101873702B

CN101873702B - Method for selecting main carrier and base station equipment

Info

Publication number: CN101873702B
Application number: CN2009100827013A
Authority: CN
Inventors: 王军; 杨宁; 胡南
Original assignee: China Mobile Communications Group Co Ltd
Current assignee: China Mobile Communications Group Co Ltd
Priority date: 2009-04-24
Filing date: 2009-04-24
Publication date: 2013-01-23
Anticipated expiration: 2029-04-24
Also published as: CN101873702A

Abstract

The invention discloses a method for selecting a main carrier and base station equipment, which are used for solving the problem of selecting a proper main carrier for user equipment. The method for selecting the main carrier of the invention comprises that: a base station selects a member carrier as a main carrier for the user equipment (UE) which is in a radio resource control (RRC) connection state; and the base station sends main carrier configuration information to the UE, wherein the main carrier configuration information comprises the frequency point information of the member carrier selected for the UE and is used for instructing the UE to monitor the member carrier selected for the UE in the RRC connection state. In the invention, the base station adopts a user main carrier mode for the UE in the RRC connection station, which is favorable for the uniform distribution of special control information on member carriers; and thus, the system performance is improved effectively, and the power consumption of the UE is reduced effectively.

Description

Main carrier selection method and base station equipment

Technical Field

The present invention relates to the field of mobile communications, and in particular, to a method for selecting a primary carrier and a base station device.

Background

Carrier Aggregation (CA) technology is an important candidate for supporting broadband transmission in a Long term evolution-Advanced (LTE-a) system. The CA technology is to divide a continuous or discrete spectrum into multiple logical Component Carriers (CCs), where uplink and downlink in a cell in the LTE-a system each include multiple CCs, and a User Equipment (UE) in the LTE-a system can receive or transmit data on multiple CCs simultaneously. A carrier aggregation diagram in an LTE-system is shown in fig. 1, where a UE may receive data on N downlink CCs and transmit data on M uplink CCs simultaneously. Because the uplink and the downlink in a cell in the LTE system respectively comprise one CC, and the UE in the LTE system can receive or send data on one CC, compared with the LTE system, the LTE-A system improves the data transmission rate of the UE and improves the system performance based on a joint scheduling strategy.

Since the UE in the LTE-a system can receive or transmit data on multiple CCs simultaneously, what transmission method is adopted for the system information and the Control information becomes one of the problems faced by the CA technology, such as transmission of a paging (paging) message on which CC, transmission of an RRC Connection Reconfiguration (RRC: Radio Resource Control) message on which CC is dedicated Control information, and the like. If the LTE-a system considers all CCs as peer-to-peer along the design principle of the existing LTE system, the system information and the control information may be transmitted on any CC, and then the UE in the LTE-a system needs to monitor and receive the information on all CCs in the cell, thereby causing an increase in the system signaling overhead and an increase in the power consumption of the UE.

The existing LTE-a system proposes a solution for a main Carrier (Anchor Carrier), and specifically may adopt two modes, namely a Cell-Specific Anchor Carrier (Cell-Specific Anchor Carrier) and a user equipment (UE-Specific Anchor Carrier). The cell primary carrier mode refers to a base station (in an LTE-system, the base station is represented by an eNB) selecting one CC as a primary carrier, and all UEs in a cell monitor related information (for example, system information and control information) on the CC; the user primary carrier mode means that the eNB selects one CC as the primary carrier of each UE in a cell, and each UE monitors related information on the CC selected by the eNB for the UE. How to select a proper primary carrier for the UE, so as to reduce the system signaling overhead and the power consumption of the UE to the maximum extent on the premise of ensuring the system performance and the data transmission rate of the UE, which is one of the problems to be solved in the prior art.

Disclosure of Invention

The invention provides a method for selecting a main carrier and base station equipment, which are used for solving the problem of how to select a proper main carrier for user equipment.

The method for selecting the main carrier provided by the invention comprises the following steps:

a base station selects a member carrier as a main carrier for User Equipment (UE) in a Radio Resource Control (RRC) connection state; and are

And sending user main carrier configuration information to the UE, wherein the user main carrier configuration information comprises frequency point information of the member carrier selected for the UE, and the user main carrier configuration information is used for indicating the UE to monitor the member carrier selected for the UE in an RRC connection state.

The base station device provided by the invention comprises:

a first selection unit, configured to select a component carrier as a primary carrier for a user equipment UE in a radio resource control RRC connected state;

the first sending unit is configured to send user primary carrier configuration information to the UE, where the user primary carrier configuration information includes frequency point information of a member carrier selected for the UE, and the user primary carrier configuration information is used to instruct the UE to monitor the member carrier selected for the UE in an RRC connected state.

According to the method for selecting the main carrier and the base station equipment, the base station selects one member carrier as the main carrier for each UE in the RRC connection state, so that the uniform distribution of the special control information on each member carrier is facilitated, and the system performance can be effectively improved; for the UE in the RRC connection state, the base station adopts the user main carrier mode, so that the data information and the special control information of the UE can be transmitted on the same member carrier, and meanwhile, the base station indicates the UE to monitor the member carrier selected for the UE in the RRC connection state in a mode of sending the user main carrier configuration information to the UE, so that the power consumption of the UE can be effectively reduced.

Drawings

Fig. 1 is a schematic diagram of carrier aggregation in an existing LTE-a system;

fig. 2 is a flowchart of a method for selecting a primary carrier according to an embodiment of the present invention;

fig. 3 is a flowchart illustrating a method for selecting a primary carrier for an RRC connected UE according to a first embodiment;

fig. 4 is a flowchart of a method for selecting a primary carrier for a UE in an RRC connected state according to the second embodiment;

fig. 5 is a block diagram of a base station apparatus according to an embodiment of the present invention;

FIG. 6 is a block diagram of a possible structure of a first selecting unit according to an embodiment of the present invention;

fig. 7 is a block diagram of another possible structure of the first selecting unit in the embodiment of the present invention.

Detailed Description

The inventor finds that the cell main carrier mode and the user main carrier mode have respective advantages and disadvantages in the invention process, and the following brief introduction is respectively carried out:

for the cell main carrier mode, the method has the advantages that: the selected main carrier wave only needs to be broadcasted to all UE in the cell in the system information, the realization is simple, and the system signaling cost is small. For the cell primary carrier mode, the disadvantages are: for the UE in RRC connection state (RRC-connection), dedicated control information of all UEs in the cell is transmitted on the same CC (i.e., primary carrier), and a large amount of dedicated control information causes uneven control information load on each CC in the cell, thereby reducing system performance; secondly, even if the data information of the UE is not transmitted on the primary carrier, the UE needs to monitor the primary carrier all the time to avoid missing the necessary dedicated control information, thereby causing an increase in power consumption of the UE; finally, the cell primary carrier mode is that the eNB designates one CC as a primary carrier for all UEs in the cell, and it cannot be ensured that each UE is in a good channel state on the primary carrier, so that the data transmission rate of the UE cannot be ensured.

For the user main carrier mode, the method has the advantages that: the eNB can select a main carrier for each UE in the cell, so that a large amount of special control information can be uniformly distributed on each CC, and the UE can be ensured to be in a good channel state on the main carrier; dedicated control information and data information of the UE may be transmitted on the same CC, and thus power consumption of the UE may be reduced. For the user primary carrier mode, the disadvantages are: for the UE in an RRC Idle state (RRC-Idle), signaling interaction between the UE and the eNB needs to be introduced for selecting the primary carrier, and in the design principle of the existing LTE-a system, the UE in the RRC Idle state does not report related information for selecting the primary carrier to the eNB, and additional interactive signaling needs to be added, so that system signaling overhead is increased; meanwhile, for the UE in the RRC idle state, the primary carrier usually only transmits the paging message, but the paging message is specified according to the existing protocol to be broadcasted in all cells of a Routing Area (RA), so that transmitting the paging message on the primary carrier of the UE can only reduce the paging overhead (one type of system signaling overhead) in the cell where the UE is located, and other cells of the Routing Area still need to broadcast the paging message, which cannot effectively reduce the paging overhead.

Therefore, the cell primary carrier mode is suitable for the UE in the RRC idle state, and has certain defects for the UE in the RRC connection state; the user primary carrier mode is suitable for UEs in an RRC connected state, but has certain drawbacks for UEs in an RRC idle state.

Based on the above analysis, the embodiment of the present invention proposes: for the UE in the RRC connection state, a user-primary carrier mode is adopted, and the eNB selects a primary carrier for the UE in the RRC connection state, where the primary carrier is UE-Specific, that is, different CCs may be selected as the primary carrier for different UEs, and the UE needs to monitor the CC selected by the eNB for the UE. The selection scheme of the main carrier wave provided by the embodiment of the invention is suitable for an LTE-A system based on a CA technology and a subsequent evolution system thereof. In the embodiment of the present invention, an LTE-a system is taken as an example for explanation, a corresponding base station is represented by an eNB, and a UE refers to an LTE-a release UE. As shown in fig. 2, the method for selecting a primary carrier according to an embodiment of the present invention includes the following steps:

s201, eNB selects a CC as a main carrier for UE in an RRC connection state;

in a specific implementation, the eNB may select a suitable CC as its primary carrier for the UE with reference to information such as a load on the CC, a capability of the UE, and a channel state of the UE on the CC.

S202, an eNB sends user-Specific anchor carrier configuration (UE-Specific anchor carrier configuration) information to a UE, wherein the UE-Specific anchor carrier configuration information comprises frequency point information of CCs selected for the UE, and the user-Specific anchor carrier configuration information is used for indicating the UE to monitor the CCs selected for the UE in an RRC connection state;

in a specific implementation, the eNB may send the user primary carrier configuration information to the UE through a specific control signaling. The user main carrier configuration information at least needs to include frequency point information of the CC selected by the eNB for the UE, so that the UE can know the CC selected by the eNB for the UE according to the frequency point information, and the CC is monitored; of course, the user equipment primary carrier configuration information may also include Cell identity (Cell Identifier), bandwidth information of CCs selected for the UE, and other information. The frequency point information of the CC generally takes the form of an identifier, and may also take the form of an actual frequency.

In the method for selecting a main carrier provided by the embodiment of the present invention, the eNB selects one CC as its main carrier for each UE in the RRC connected state, which is beneficial to uniform distribution of dedicated control information on each CC, so as to effectively improve system performance; for the UE in the RRC connection state, the eNB adopts the user main carrier mode, so that the data information and the special control information of the UE can be transmitted on the same CC, and meanwhile, the eNB instructs the UE to monitor the selected CC by sending the user main carrier configuration information to the UE, so that the power consumption of the UE can be effectively reduced.

The following describes in detail a method for selecting a primary carrier for an RRC connected UE by an eNB for various specific application scenarios.

Example one

In this embodiment, the specific application scenarios are as follows: when the UE is in the process of transferring from the RRC idle state to the RRC connected state, the eNB selects one CC as a main carrier for the UE, and sends user main carrier configuration information to the UE. For the specific application scenario, as shown in fig. 3, the method includes the following steps:

s301, the UE performs channel quality detection on the supported CC in an RRC idle state to obtain a detection result;

in the process of transferring the UE from the RRC idle state to the RRC connected state, the eNB needs to select a suitable CC as its primary carrier for the UE with reference to information such as a load on the CC, a capability of the UE, and a channel state of the UE on the CC, so that the UE in the RRC idle state needs to perform channel quality detection on the CC supported by the UE according to its own capability and report an obtained detection result to the eNB. The detection result obtained by the UE performing the channel quality detection on the CC supported by the UE may reflect the channel state of the UE on the CC, and the higher the detection result obtained by the UE performing the channel quality detection on the CC is, the better the channel state of the UE on the CC is. The detection result reported by the UE may be represented by parameters such as Reference Signal Received Power (RSRP)/Reference Signal Received Power (RSRQ)/Channel Quality Indicator (CQI). In order to control the overhead required for reporting the detection result, the UE may only report a part of the detection results with better channel quality, for example, the UE only reports the detection result that the channel quality exceeds a set threshold, and the set threshold may be placed in system information (for example, SIB) and sent to the UE; the UE may extract the set threshold from the system information.

S302, in the process that the UE is switched from the RRC idle state to the RRC connection state, the UE reports a detection result obtained by detecting the channel quality of the supported CC in the RRC idle state to the eNB;

in a specific implementation, the detection result may be carried in an RRC Connection request Message (RRC ConnectionRequest) or an RRC Connection reestablishment request Message (RRC connectionreestablishment request Message) and reported to the eNB, or a signaling Message is added to transmit the detection result.

S303, the eNB selects, according to the received detection result, a CC with the channel quality exceeding a set threshold (referred to as a first threshold for convenience of distinguishing) and the smallest load as a primary carrier of the UE;

of course, the selection of the primary carrier for the UE by the eNB is not limited to the above manner, and for example, the selection may be performed only according to the channel quality without considering the load of the CC; or, a loading threshold may also be set, and a CC whose channel quality exceeds the first threshold and whose loading is less than the loading threshold is selected as the primary carrier of the UE. If there are a plurality of CCs satisfying the condition, one of them is selected. In a specific implementation, the number of UEs in the RRC connected state may be used as the load of the CC, and of course, the corresponding load threshold is also the number of UEs, and may be set to 3, for example.

S304, the eNB sends user main carrier configuration information to the UE, wherein the user main carrier configuration information comprises frequency point information of the CC selected for the UE, and the user main carrier configuration information is used for indicating the UE to monitor the CC selected for the UE in an RRC connection state;

in a specific implementation, the user primary carrier configuration information may be carried in an RRC connection Setup Message (rrcconnectionsetup Message) or an RRC connection reestablishment Message (RRC connectionrequest Message) and sent to the UE, or a signaling Message is added to transmit the user primary carrier configuration information.

According to the scheme provided by the first embodiment, the eNB selects a proper CC as the main carrier of the UE according to information such as the load on the CC, the channel state of the UE on the CC, the capability of the UE and the like, so that the UE is ensured to be in a good channel state on the main carrier, and the data transmission rate and the data transmission reliability are improved; the eNB selects the main carrier for the UE in the process of transferring the UE from the RRC idle state to the RRC connection state, so that the timeliness of the UE in a user main carrier mode in the RRC connection state can be ensured; the UE detects and reports the channel quality of the supported CC in an RRC idle state, so that the reliability of the eNB for selecting the main carrier for the UE can be improved.

Example two

In this embodiment, the specific application scenarios are as follows: in the process that the UE is in an RRC connection state, the eNB selects one CC as a main carrier for the UE, and sends user main carrier configuration information to the UE. For the specific application scenario, as shown in fig. 4, the method includes the following steps:

s401, eNB sends CC detection notification to UE in RRC connection state;

in the RRC connected state of the UE, the primary carrier of the UE may need to be adjusted in consideration of the change of the channel state of the UE on different CCs, the change of the load on different CCs, and other factors. Therefore, the eNB sends a CC detection notification to the UE to instruct the UE to perform channel quality detection and reporting on the CC. The eNB may indicate, in the CC detection notification, each CC for which the UE needs to perform channel quality detection according to the capability of the UE.

S402, the UE detects the channel quality of the supported CC according to the received CC detection notice to obtain a detection result;

and if the detection notification does not indicate that the UE needs to perform the channel quality detection, the UE performs the channel quality detection on the supported CCs according to the self-capability.

S403, the UE reports the detection result obtained by the channel quality detection to the eNB;

in a specific implementation, a signaling message may be added to transmit the detection result.

S404, the eNB selects, according to the received detection result, one CC with the channel quality exceeding a set threshold (for convenience of distinguishing, may be referred to as a second threshold) and the smallest load as the primary carrier of the UE.

Of course, the selection of the primary carrier for the UE by the eNB is not limited to the above manner, and for example, the selection may be performed only according to the channel quality without considering the load of the CC; or, a loading threshold may also be set, and a CC whose channel quality exceeds the second threshold and whose loading is less than the loading threshold is selected as the primary carrier of the UE. If there are a plurality of CCs satisfying the condition, one of them is selected. In a specific implementation, the number of UEs in the RRC connected state may be used as the load of the CC, and of course, the corresponding load threshold is also the number of UEs, and may be set to 3, for example.

S405, the eNB sends user main carrier configuration information to the UE, wherein the user main carrier configuration information comprises frequency point information of the CC selected for the UE, and the user main carrier configuration information is used for indicating the UE to monitor the CC selected for the UE in an RRC connection state;

in a specific implementation, the UE may send the UE the configuration information of the user primary carrier carried in an RRC connection Reconfiguration Message (RRCConnection Reconfiguration Message), or add a signaling Message for transmitting the configuration information of the user primary carrier.

In the scheme provided by the second embodiment, the eNB selects a proper CC as its main carrier for the UE according to information such as the load on the CC, the channel state of the UE on the CC, the capability of the UE, and the like, so as to ensure that the UE is in a good channel state on its main carrier, thereby improving the data transmission rate and the data transmission reliability; the eNB indicates the UE to detect and report the channel quality of the supported CC by issuing a CC detection notice in the process that the UE is in an RRC connection state, so that the conditions of the change of the channel state of the UE on different CCs, the change of loads on different CCs and the like can be effectively dealt with, and the reliability of the eNB for selecting the main carrier for the UE is improved.

A Physical Downlink Control Channel (PDCCH) between an eNB and a UE related in the CA technology includes three design schemes: a joint downlink physical control channel (JointPDCCH) structure, which is to adopt one PDCCH on one of a plurality of CCs to indicate resource allocation information on the plurality of CCs within one Transmission Time Interval (TTI); an independent downlink physical control channel (Separate PDCCH) structure, which is to adopt an independent PDCCH on each CC in a plurality of CCs, and is used for indicating resource allocation information of one UE on the CC in one TTI; the first level is control information, which includes related information of a next level PDCCH (e.g., number of carriers, CCE level control channel element layer, offset position of search space, etc.), the number of CCs allocated to the UE (no matter whether the next level PDCCH is Joint PDCCH or Separate PDCCH), and the first level control information may be an independent data block or may be placed in one PDCCH for transmission. The embodiment of the invention further provides that when the UE is in the RRC connection state, if the PDCCH design scheme adopts a Joint PDCCH structure, the Joint PDCCH is borne on a main carrier of the UE; if the Separate PDCCH structure is adopted, a main control PDCCH (such as a PDCCH comprising other PDCCH blind detection information) is carried on a main carrier of the UE; if a two-level PDCCH structure is adopted, the first-level control information is carried on a main carrier of the UE and transmitted, wherein if the first-level control information is an independent data block, the data block is transmitted on the main carrier of the UE, and if the first-level control information is placed in one PDCCH, the PDCCH in which the first-level control information is placed is carried on the main carrier of the UE. Preferably, when the UE is in the RRC connected state, control information of other CCs, such as switching information of other CCs, may also be transmitted on the primary carrier of the UE.

The embodiment of the invention further provides that: for the UE in the RRC idle state, a Cell-major carrier mode is adopted, and the eNB designates the CC as a major carrier of all the UEs in the RRC idle state, where the major carrier is Cell-Specific, that is, the same CC is designated as a major carrier for all the UEs, and all the UEs in the RRC idle state need to monitor the designated CC. The method for selecting the main carrier further comprises the following steps:

step 1, in the process of transferring UE from an RRC connection state to an RRC idle state, an eNB selects a designated CC as a main carrier for the UE, wherein the designated CC is the CC selected by the eNB as the main carrier for all the UE in the RRC idle state;

step 2, the eNB sends cell main carrier configuration information to the UE, wherein the cell main carrier configuration information comprises frequency point information of the designated CC, and the cell main carrier configuration information is used for indicating the UE to monitor the designated CC in an RRC idle state;

consistent with the configuration information of the user main carrier, the configuration information of the cell main carrier at least needs to include the frequency point information of the designated CC, so that the UE can know the designated CC according to the frequency point information, and the designated CC is monitored; of course, the Cell primary carrier configuration information may also include Cell identity (Cell Identifier), bandwidth information of the specified CC, and other information.

In the embodiment of the invention, the eNB selects the main carrier for the UE in the RRC idle state by adopting the cell main carrier mode, so that the problem of overlarge system signaling overhead caused by the user main carrier mode to the UE in the RRC idle state can be effectively avoided.

Based on the same inventive concept, the embodiment of the present invention further provides a base station device, and as the principle of the base station device for solving the problem is consistent with the method for selecting the primary carrier, the implementation of the device may refer to the implementation of the method, and repeated details are omitted.

As shown in fig. 5, the base station device provided in the embodiment of the present invention includes:

a first selecting unit 501, configured to select one CC as its primary carrier for a UE in an RRC connected state;

a first sending unit 502, configured to send, to the UE, user primary carrier configuration information, where the user primary carrier configuration information includes frequency point information of a CC selected for the UE, and the user primary carrier configuration information is used to instruct the UE to monitor the CC selected for the UE in an RRC connected state.

Preferably, the base station apparatus may further include:

a second selecting unit 503, configured to select, as a primary carrier of the UE, a designated CC for the UE in a process of transitioning the UE from the RRC connected state to the RRC idle state, where the designated CC is a CC selected by the base station for all UEs in the RRC idle state as the primary carrier;

a second sending unit 504, configured to send cell primary carrier configuration information to the UE, where the cell primary carrier configuration information includes frequency point information of the designated CC, and the cell primary carrier configuration information is used to instruct the UE to monitor the designated CC in the RRC idle state.

In a specific implementation, as shown in fig. 6, the first selecting unit 501 may include:

a first receiving subunit 601, configured to receive, in a process that the UE transitions from the RRC idle state to the RRC connected state, a detection result obtained by performing channel quality detection on the supported CC in the RRC idle state reported by the UE;

a first selecting subunit 602, configured to select, according to the received detection result, one CC with the channel quality exceeding a first threshold and the smallest load as the primary carrier of the UE.

In a specific implementation, as shown in fig. 7, the first selecting unit 501 may include:

a notification subunit 701, configured to send a CC detection notification to a UE in an RRC connected state;

a second receiving subunit 702, configured to receive a detection result obtained by performing channel quality detection on the supported CC by the UE according to the CC detection notification and reporting the detection result;

a second selecting subunit 703 is configured to select, according to the received detection result, one CC with the channel quality exceeding the second threshold and the smallest load as the primary carrier of the UE.

As will be appreciated by one skilled in the art, embodiments of the present invention may be provided as a method, apparatus, or computer program product. Accordingly, the present invention may take the form of an entirely hardware embodiment, an entirely software embodiment or an embodiment combining software and hardware aspects. Furthermore, the present invention may take the form of a computer program product embodied on one or more computer-usable storage media (including, but not limited to, disk storage, CD-ROM, optical storage, and the like) having computer-usable program code embodied therein.

It will be apparent to those skilled in the art that various changes and modifications may be made in the present invention without departing from the spirit and scope of the invention. Thus, if such modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalents, the present invention is also intended to include such modifications and variations.

Claims

1. A method for selecting a primary carrier, comprising:

Sending user main carrier configuration information to the UE, wherein the user main carrier configuration information comprises frequency point information of the member carrier selected for the UE, and the user main carrier configuration information is used for indicating the UE to monitor the member carrier selected for the UE in an RRC connection state;

the method for selecting the main carrier for the UE in the RRC connection state by the base station specifically comprises the following steps:

in the process that the UE is switched from the RRC idle state to the RRC connection state, the UE reports a detection result obtained by detecting the channel quality of the supported member carrier in the RRC idle state to the base station; the base station selects a member carrier with the channel quality exceeding a first threshold and the minimum load as a main carrier of the UE according to the received detection result; or

a base station sends a member carrier detection notification to UE in an RRC connection state; the UE carries out channel quality detection on the supported member carriers according to the received member carrier detection notice and reports the obtained detection result to the base station; and the base station selects a member carrier with the channel quality exceeding a second threshold and the minimum load as a main carrier of the UE according to the received detection result.

2. The method of claim 1, wherein the method for the base station to select the primary carrier for the UE in the RRC connected state specifically comprises: in the process that the UE is switched from the RRC idle state to the RRC connection state, the UE reports a detection result obtained by detecting the channel quality of the supported member carrier in the RRC idle state to the base station; the base station selects a member carrier with the channel quality exceeding a first threshold and the minimum load as a main carrier of the UE according to the received detection result;

the detection result is carried in an RRC Connection Request Message and is reported to the base station, and the user main carrier configuration information is carried in an RRC Connection establishment Message RRCConnection Setup Message and is sent to the UE;

or,

the detection result is carried in an RRC Connection Reestablishment Request Message and is reported to the base station, and the user main carrier configuration information is carried in the RRC Connection Reestablishment Message and is sent to the UE.

3. The method of claim 1, wherein the method for the base station to select the primary carrier for the UE in the RRC connected state specifically comprises: a base station sends a member carrier detection notification to UE in an RRC connection state; the UE carries out channel quality detection on the supported member carriers according to the received member carrier detection notice and reports the obtained detection result to the base station; the base station selects a member carrier with the channel quality exceeding a second threshold and the minimum load as a main carrier of the UE according to the received detection result;

and the user main carrier configuration information is carried in an RRC connection reconfiguration Message and is sent to the UE.

4. The method according to any of claims 1 to 3, wherein the detection result includes the component carriers whose channel quality exceeds a third threshold and the corresponding channel quality, and the third threshold is carried by the base station in system information and sent to the UE.

5. The method of any of claims 1 to 3, further comprising:

in the process that the UE is switched from the RRC connection state to the RRC idle state, the base station selects a designated member carrier as a main carrier for the UE, wherein the designated member carrier is the member carrier which is selected by the base station for all the UE in the RRC idle state and is used as the main carrier; and are

And sending cell main carrier configuration information to the UE, wherein the cell main carrier configuration information comprises frequency point information of the appointed member carrier, and the cell main carrier configuration information is used for indicating the UE to monitor the appointed member carrier in an RRC idle state.

6. The method of claim 1, wherein control information bearers for other component carriers are transmitted on a primary carrier of the UE.

7. The method of claim 1,

if a Joint physical control channel (Joint PDCCH) structure is adopted between the base station and the UE, the Joint PDCCH is borne on a main carrier of the UE;

if an independent downlink physical control channel Separate PDCCH structure is adopted between the base station and the UE, the main control PDCCH is carried on a main carrier of the UE;

and if a two-stage Physical Downlink Control Channel (PDCCH) structure is adopted between the base station and the UE, carrying the first-stage control information on a main carrier of the UE for transmission.

8. The method of claim 1, wherein the user primary carrier configuration information further comprises a cell identity and/or bandwidth information of a component carrier selected for the UE.

9. A base station apparatus, comprising:

a first sending unit, configured to send user primary carrier configuration information to the UE, where the user primary carrier configuration information includes frequency point information of a component carrier selected for the UE, and the user primary carrier configuration information is used to instruct the UE to monitor the component carrier selected for the UE in an RRC connected state;

the first selection unit includes:

the first receiving subunit is configured to receive, in a process of transferring the UE from the RRC idle state to the RRC connected state, a detection result obtained by performing channel quality detection on the supported component carrier in the RRC idle state reported by the UE; a first selecting subunit, configured to select, according to the received detection result, one component carrier with a smallest load and a channel quality exceeding a first threshold as a primary carrier of the UE; or

The first selection unit includes:

a notification subunit, configured to send a component carrier detection notification to a UE in an RRC connected state; a second receiving subunit, configured to receive a detection result obtained by performing channel quality detection on the supported component carrier by the UE according to the component carrier detection notification and reporting the detection result; and the second selection subunit is used for selecting one member carrier with the channel quality exceeding a second threshold and the minimum load as the main carrier of the UE according to the received detection result.

10. The base station apparatus of claim 9, further comprising:

a second selecting unit, configured to select, for a UE, an assigned component carrier as a primary carrier of the UE when the UE transitions from an RRC connected state to an RRC idle state, where the assigned component carrier is a component carrier selected by a base station for all UEs in the RRC idle state as the primary carrier;

and a second sending unit, configured to send cell primary carrier configuration information to the UE, where the cell primary carrier configuration information includes frequency point information of a designated member carrier, and the cell primary carrier configuration information is used to instruct the UE to monitor the designated member carrier in an RRC idle state.