WO2011122045A1 - Wireless communication base station, wireless communication device and wireless communication system - Google Patents

Abstract

Disclosed is a wireless communication base station that is provided with a receiving unit for receiving information transmitted by a wireless communication device, and a component carrier determination unit for determining a component carrier set for use, when it is determined to communicate with a wireless communication device using a component carrier set that includes a first component carrier used as a reference carrier and at least one second component carrier used simultaneously with the first component carrier, or when it is determined to change the carrier configuration of said component carrier set during communication with a wireless communication device using a component carrier set. The base station is further provided with a difference information creation unit for creating difference information, which is difference information between the setting information included in the component carrier set being used, specifically, between the setting information of the first component carrier and the setting information of the second component carrier, which acts as a reference. Thus, it is possible to minimize the amount of signaling relating to the settings of component carriers in a carrier aggregation.

Description

Radio communication base station, radio communication apparatus, and radio communication system

The present invention relates to a radio communication base station, a radio communication apparatus, and a radio communication system capable of communicating by using each component carrier of a plurality of communication cells simultaneously by carrier aggregation.

The standardization organization 3GPP (The 3rd Generation Partnership Project) is promoting the standardization of LTE (Long Term Evolution) as the next generation communication standard of W-CDMA (Wideband Code Division Multiple Access).

In LTE, one radio communication base station (evolved NodeB: eNB, also simply referred to as “base station”) manages a plurality of communication cells (hereinafter simply referred to as “cells”), and a radio communication terminal (User Equipment: UE, also simply referred to as “terminal”) belongs to one of the cells. As a terminal state (UE state), a state that does not have an individual connection with a base station is called an “idle state (also called“ idle mode ”or“ RRC_IDLE ”), and a state that has an individual connection with a base station. It is called “connected state (connected mode, also called“ RRC_CONNECTED ”)”. A terminal in an idle state cannot transmit / receive individual data to / from a base station, and only receives incoming information or broadcast information transmitted to all terminals in a cell. When individual data is transmitted and received between the terminal and the base station, a connection setup procedure is performed, and a dedicated radio bearer (radio 端末 bearer) is established between the terminal and the base station so that the terminal is in an idle state. To the connected state.

Normally, a terminal in a connected state follows the setting (measurement control) related to reception quality measurement of a cell (serving cell) and a neighboring cell (neighbor cell) provided by the accessing base station (source base station). The reception quality is measured by a pilot channel (Common PIlot CHannel: CPICH) of a cell and an adjacent cell. The terminal reports the reception quality measurement result (measurement report) to the source base station periodically or for each set event. The source base station determines a base station (target base station) to which the terminal performs handover from the source base station based on the report of the reception quality measurement result.

Also, the standardization organization 3GPP is proceeding with standardization of LTE-Advanced (Long Term Evolution Advanced: LTE-A) as a next-generation wireless communication standard compatible with LTE. LTE-A is a next-generation mobile communication standard that has evolved from LTE, and aims to provide improved mobile communication services.

In LTE-A, introduction of “Carrier Aggregation” in which a terminal simultaneously uses a plurality of carrier frequencies managed by one base station is considered.

FIG. 28 is a diagram illustrating an example of a set of component carriers used by the terminal in carrier aggregation. In the example of FIG. 28, the terminal uses three consecutive downlink component carriers (carrier A, carrier B, carrier C) each having a frequency band of 20 MHz and two uplink component carriers (carrier a, carrier b). Carry out carrier aggregation. For example, downlink carriers A and B are used as a pair with uplink carrier a, and downlink carrier C is used as a pair with uplink carrier b. As described above, the use of a plurality of component carriers is expected to improve the throughput of communication between the terminal and the base station.

In this specification, a cell is a wireless network object that can be uniquely identified by a terminal from an identifier sent from one base station to a geographical area. One cell is composed of a pair of uplink and downlink component carriers.

The instruction of carrier aggregation is performed at the initiative of the base station. The base station selects a component carrier set to be used for carrier aggregation based on the bandwidth that the terminal can support, the number of component carriers, and the like, and clearly indicates the set to the terminal. The carrier aggregation start instruction and the component carrier set instruction are notified by dedicated signaling between the base station and the terminal. The notification timing is notified together with “RRC connection reconfiguration”, which is a message individually sent from the base station to the terminal to notify the setting of RRC (Radio Resource Control) connection at the time of terminal connection setup. Conceivable. In addition, it is conceivable that, at the time of handover, notification is made with a “HO command” which is a message sent from the source base station to instruct the terminal to perform handover. Furthermore, it is conceivable that notification is made by individual signaling from the base station to the terminal at an arbitrary timing.

Japanese Unexamined Patent Publication No. 2009-49614

3GPP TSG RAN WG2 # 68bis Tdoc-R2-101015, “Urgent Information to be configured at CC addition”, Huawei 3GPP TSG RAN Technical Specification 36.331 v9.1.0, “E-UTRAN RRC Protocol specification (Release 9)”

In the standardization organization 3GPP, it is assumed that up to five component carriers can be used simultaneously as carrier aggregation, for example, as a pair of uplink (uplink) and downlink (downlink). In this case, a maximum of four component carriers can be added and set. However, if a plurality of component carriers are added and set for each carrier, the message size for this procedure increases. As a result, the amount of signaling related to the component carrier setting increases.

An object of the present invention is to provide a radio communication base station, a radio communication apparatus, and a radio communication system that can reduce the amount of signaling related to the setting of component carriers in carrier aggregation.

The present invention is a radio communication base station capable of communicating with a radio communication device by simultaneously using each component carrier of a plurality of communication cells, the receiving unit receiving information transmitted from the radio communication device, and the reception The component receives information and communicates with the wireless communication apparatus using a component carrier set including a first component carrier used as a reference carrier and at least one second component carrier used simultaneously with the first component carrier. When it is determined, or when it is determined to change the carrier configuration of the component carrier set during communication with the wireless communication device using a component carrier set, a component carrier determination unit that determines a component carrier set to be used; The computer Second / first carrier difference information that is difference information with respect to the setting information of the second component carrier with reference to the setting information of the first component carrier included in the used component carrier set determined by the component carrier determining unit. A wireless communication base comprising: a difference information generation unit; a setting message generation unit that generates a setting message including the second / first inter-carrier difference information; and a transmission unit that transmits the setting message to the wireless communication device. Provide stations.

The radio communication base station includes a component carrier information holding unit that holds setting information of each component carrier of the plurality of communication cells managed by the radio communication base station, and the difference information generation unit includes the used component carrier set. The setting information of the first component carrier and the setting information of the second component carrier included in the are extracted from the component carrier information holding unit.

In the radio communication base station, at least a part of the second component carrier included in the used component carrier set determined by the component carrier determining unit is set to the second component carrier included in the used component carrier set before the component carrier change. The difference information generating unit uses the setting information of the second component carrier before changing the component carrier as a reference, and the difference information with the setting information of the second component carrier after changing the component carrier The second / second inter-carrier difference information is generated, and the message generation unit generates a setting message including the second / second inter-carrier difference information.

The radio communication base station includes a handover determination unit that determines whether or not handover is necessary based on information received by the reception unit, and determines a handover destination communication cell when it is determined to perform handover, When the handover determining unit determines to perform handover, the component carrier determining unit determines a used component carrier set after handover, and the difference information generating unit is configured to include a first component included in the used component carrier set before handover. When the carrier and the first component carrier included in the used component carrier set after the handover are different, the setting information of the first component carrier after the handover based on the setting information of the first component carrier before the handover; Generating a first / between the first carrier difference information is difference information,
The setting message generation unit generates a setting message including the first / first inter-carrier difference information.

In the radio communication base station, when at least part of the second component carrier included in the used component carrier set after the handover is different from the second component carrier included in the used component carrier set before the handover, the difference information generation When generating the second / first carrier difference information, the unit uses the setting information of the first component carrier after the handover as a reference.

In the radio communication base station, when the radio communication base station and the radio communication base station that manages the handover destination communication cell determined by the handover determining unit are different, the setting message generating unit is configured to add a predetermined message to the setting message. Include information.

In the wireless communication base station, when the wireless communication base station and the wireless communication base station that manages the communication cell of the handover destination determined by the handover determining unit are different, the difference information generating unit performs communication before the handover. Receiving setting information of the first component carrier before the handover from a radio communication base station managing a cell, and using the received first component carrier setting information as a reference, the first / first inter-carrier difference information and the Second / first inter-carrier difference information is generated.

In the wireless communication base station, the first component carrier is a primary component carrier.

The wireless communication base station includes a reference component carrier selection unit that selects at least one of the first component carriers from the used component carrier set.

In the wireless communication base station, the reference component carrier selection unit selects the first component carrier from a plurality of sets of component carriers having similar conditions in the used component carrier set.

The present invention is a wireless communication apparatus capable of communicating with the wireless communication base station by simultaneously using each component carrier of a plurality of communication cells managed by the wireless communication base station, and transmitted from the wireless communication base station A receiving unit configured to receive a setting message; and a component carrier setting unit configured to set at least one component carrier based on component carrier setting information included in the setting message received by the receiving unit. When the setting message includes second / first inter-carrier difference information that is difference information with respect to the setting information of the second component carrier with reference to the setting information of the first component carrier, Setting information of one component carrier and between the second / first carriers Referring to partial information, to provide a wireless communication device for setting the second component carrier.

In the above wireless communication apparatus, the component carrier setting unit includes difference information from the setting information of the first component carrier after handover based on the setting information of the first component carrier before handover in the setting message. When 1 / first inter-carrier difference information is included, the first component carrier after the handover is set with reference to the setting information of the first component carrier in use and the first / first inter-carrier difference information .

In the wireless communication apparatus, the first component carrier setting information that is a reference for the second / first inter-carrier difference information is the first component carrier setting information after the handover.

In the wireless communication device, the component carrier setting unit sets a component carrier set in use in communication with the wireless communication base station according to predetermined information included in the setting message transmitted from the wireless communication base station. Delete all included component carrier settings.

In the above wireless communication device, the first component carrier is a primary component carrier.

The present invention is a radio communication system in which a radio communication apparatus can communicate with the radio communication base station by simultaneously using component carriers of a plurality of communication cells managed by the radio communication base station, wherein the radio communication base station A first receiving unit that receives information transmitted from the wireless communication device, a first component carrier that is used as a reference carrier by processing the information received by the first receiving unit, and the first component carrier at the same time When it is determined to communicate with the wireless communication device using a component carrier set including at least one second component carrier to be used, or during communication with the wireless communication device using a component carrier set, the component carrier set If you decide to change the carrier structure, Difference information between the component carrier determining unit that determines the component carrier set and the setting information of the second component carrier based on the setting information of the first component carrier included in the used component carrier set determined by the component carrier determining unit A difference information generating unit that generates second / first inter-carrier difference information, a setting message generating unit that generates a setting message including the second / first inter-carrier difference information, and the setting message as the wireless communication. A transmission unit that transmits to the device, wherein the wireless communication device includes a second reception unit that receives the setting message transmitted from the wireless communication base station, and component carrier setting information included in the setting message. Based on at least one component carrier A component carrier setting unit that performs setting, and the component carrier setting unit, when the setting message includes the second / first carrier difference information, the setting information of the first component carrier and the second The wireless communication system for setting the second component carrier is provided with reference to the first inter-carrier difference information.

The radio communication base station, radio communication apparatus, and radio communication system according to the present invention can reduce the amount of signaling related to component carrier settings in carrier aggregation.

The figure which shows signaling when a carrier aggregation is instruct | indicated from a base station to a terminal, when a terminal changes from an idle state to a connected state Diagram showing an example of the used component carrier set The figure which shows an example of the setting by the difference information on the basis of a primary component carrier (PCC) The block diagram which shows the internal structure of the base station of 1st Embodiment The flowchart which shows a part of operation | movement of the base station of 1st Embodiment at the time of establishing RRC connection The block diagram which shows the internal structure of the terminal of 1st Embodiment The flowchart which shows a part of operation | movement of the terminal of 1st Embodiment at the time of establishing an RRC connection. The figure which shows the structural example of the RRC connection setting (RRC | Connection * Reconfiguration) message transmitted to a terminal from a base station. The figure which shows the signaling between the terminal and a base station at the time of a hand-over The figure which shows an example of the use component carrier set before and behind a handover The block diagram which shows the internal structure of the base station of 2nd Embodiment The flowchart which shows a part of operation | movement of the base station of 2nd Embodiment. The flowchart which shows a part of operation | movement of the terminal of 2nd Embodiment. The ASN. Example of message structure in one format The ASN. Example of message structure in one format The ASN. Example of message structure in one format ASN. Example of message structure in one format ASN.1 which notifies the setting of addition / change of the downlink component carrier used by the terminal. Example of message structure in one format ASN.1 which notifies the setting of addition / change of uplink component carrier used by the terminal. Example of message structure in one format Example of message structure to notify the ID (baseCC) of the reference component carrier in the downlink component carrier addition / change information (DLCCToAddMod) Example of message structure to notify ID (baseCC) of base component carrier in uplink component carrier addition / change information (ULCCToAddMod) Example of message configuration indicating group ID (groupID) and main component carrier (groupAnchorCC) in the group in DL component addition / change information (DLCCToAddMod) Example of message configuration that indicates the group ID (groupID) and the main component carrier (groupAnchorCC) in the group in the uplink component carrier addition / change information (ULCCToAddMod) The block diagram which shows the internal structure of the base station of 3rd Embodiment The flowchart which shows a part of operation | movement of the base station of 3rd Embodiment. The block diagram which shows the internal structure of the terminal of 3rd Embodiment The flowchart which shows a part of operation | movement of the terminal of 3rd Embodiment. The figure which shows an example of the set of the component carrier which a terminal uses by a carrier aggregation The figure which shows an example of the change of PCC and SCC in the component carrier set in use The flowchart which shows a part of operation | movement of the source base station in 2nd Embodiment in the case of performing the handover (inter-eNB | HO) between base stations. The flowchart which shows a part of operation | movement of the target base station in 2nd Embodiment in the case of performing the hand-over between base stations (inter-eNB | HO).

Hereinafter, embodiments of the present invention will be described with reference to the drawings.

In carrier aggregation, a component carrier set includes one primary component carrier (Primary Component Carrier, hereinafter also referred to as “PCC”) for each downlink and uplink. The uplink PCC is a component carrier that transmits layer 1 control information such as an Ack / Nack, a scheduling request (SR), and a channel quality notification (Channel Quality Indicator: CQI). The downlink PCC is always in an active state, and is a component carrier that acquires information (Non-Access Stratum) such as terminal location information. Component carriers other than the PCC included in the component carrier set used by the terminal are referred to as secondary component carriers (hereinafter referred to as “SCC”). A cell composed of a downlink PCC and an uplink PCC is referred to as a primary cell (hereinafter referred to as “Pcell”). A cell composed of a downlink SCC and an uplink SCC is called a secondary cell (hereinafter referred to as “SCell”).

FIG. 1 is a diagram illustrating signaling when a carrier aggregation is instructed from a base station to a terminal when the terminal transitions from an idle state to a connected state. As shown in FIG. 1, the terminal transmits a RACH preamble message to the base station, and sends an RRC connection request (RRC connection request) message to communicate with the base station according to the response (RACH response). Send. If the base station determines that the connection with the terminal can be established based on the radio wave status and the availability of communication resources, the base station sends an RRC connection setup (RRC connection setup) message to the terminal. In response to this message, the terminal sends an RRC connection setup complete (RRC connection setup complete) message to the base station.

Thereafter, the base station transmits an RRC connection setup (RRC connection reconfiguration) message including radio resource setup information and physical channel setup information to the terminal. At this time, when the base station instructs the terminal to start carrier aggregation, information on the component carrier to be added is included in the RRC connection setup message. The base station also transmits a message (Security メ ッ セ ー ジ mode command) including security settings for communication with the base station to the terminal.

Thereafter, when the RRC connection with the base station, the setting of the additional component carrier and the security setting are completed, the terminal sends a security mode completion (Security Mode Complete) message and an RRC connection setup complete (RRC connection reconfiguration complete) message to the base station. Send. Thereafter, the terminal starts carrier aggregation using the component carrier instructed from the base station.

FIG. 2 is a diagram showing an example of a used component carrier set. The base station manages component carriers CC1 to CC4 for the downlink (DownLink: DL) and manages component carriers CCa to CCd for the uplink (UpLink: UL). In the example shown in FIG. 2, the terminal is camp-on to the downlink component carrier CC1 when in the idle state, and the RRC connection setup (RRC) for transitioning to the connected state on the downlink component carrier CC1. When connection (setup) is performed, the pair of component carriers CC1 and CCa becomes the primary component carrier (PCC) for the downlink and uplink.

In this example, since component carriers CC2, CC3, CCb, and CCc are indicated as additional component carriers in the RRC connection setup (RRCRRconnection reconfiguration) message sent from the base station to the terminal, these component carriers are secondary. Used as a component carrier (SCC). Therefore, as shown in FIG. 2, the used component carrier sets of this example are three downlink component carriers CC1, CC2, CC3 and three downlink component carriers CCa, CCb, CCc.

(First embodiment)
In the first embodiment, when a component carrier used as an SCC is added or changed, difference information (delta configuration) of the component carrier based on the PCC is used. For this reason, the amount of signaling regarding addition or change of a component carrier can be minimized.

FIG. 3 is a diagram illustrating an example of setting based on difference information based on PCC. In the example of FIG. 3, the PCC is a pair of component carriers CC1 and CCa, and a pair of component carriers CC2 and CCb and component carriers CC3 and CCc are set as additional component carriers (additional SCC). Each difference between the setting information (SCC1Cconfiguration) of SCC1 and the setting information (SCC2 configuration) of SCC2 with respect to the setting information (PCC configuration) of PCC is only the parameter “config「 B ”. At this time, the setting information (delta configuration) related to the additional component carrier included in the RRC connection setup (RRC connection reconfiguration) message sent from the base station to the terminal is only "config B1" for SCC1 and "config B2" for SCC2. Only.

When the terminal receives the RRC connection setting message including the additional component carrier, the “config A” and “config C” parameters of the additional SCC use the PCC settings as they are, and the parameters of “config B” are SOC1. “Config B1” is set for “SO”, and “config B2” is set for SOC2. Note that each of the PCC configuration information (PCC configuration) and the SCC configuration information (SCC configuration) includes frequency information, band information, radio resource configuration information, physical channel configuration information, and the like.

FIG. 4 is a block diagram illustrating an internal configuration of the base station according to the first embodiment. As illustrated in FIG. 4, the base station according to the first embodiment includes a reception unit 101, an information processing unit 103, a component carrier determination unit 105, a component carrier information holding unit 107, an information extraction unit 109, and a setting. A message generation unit 111 and a transmission unit 113 are provided.

The receiving unit 101 receives information such as data, messages, terminal performance information, and reception quality measurement results transmitted from the terminal via the antenna 115.

The information processing unit 103 processes the information received by the receiving unit 101 and outputs an instruction or the like to the component carrier determining unit 105. For example, the information processing unit 103 determines to start carrier aggregation or change the carrier configuration of the component carrier set, and notifies the component carrier determination unit 105 of the determination content. In addition, when the information processing unit 103 determines to establish an RRC connection without performing carrier aggregation, the information processing unit 103 notifies the component carrier determination unit 105 of the determination content. The information processing unit 103 determines whether to perform carrier aggregation based on the performance information of the terminal included in the information received by the receiving unit 101. In addition, the information processing unit 103 determines a change in the carrier configuration of the component carrier set based on the reception quality measurement result.

The component carrier determining unit 105 becomes a set of component carriers to be used (used component carrier set) and a PCC in response to the start of carrier aggregation notified from the information processing unit 103 or a change in the carrier configuration of the component carrier set. Determine the component carrier. The used component carrier set is a set of component carriers in a range that can be used by the terminal, which is determined by the component carrier determining unit 105 based on the terminal performance information, reception quality measurement result, and the like. When the component carrier determination unit 105 receives an instruction from the information processing unit 103 to establish an RRC connection, the component carrier determination unit 105 determines a component carrier that constitutes the RRC connection.

The component carrier information holding unit 107 holds information such as frequency information, band information, radio resource setting information, and physical channel setting information of all component carriers managed by the base station. The component carrier information holding unit 107 holds information on a component carrier set used between the base station and the terminal. The component carrier information holding unit 107 may be provided separately from the base station in a state where it can communicate with the base station via the network.

The information extraction unit 109 uses the component carrier setting information used as the primary component carrier (PCC) and the component carrier setting information used as the secondary component carrier (PCC) among the used component carrier sets determined by the component carrier determination unit 105 as components. Extracted from the carrier information holding unit 107. At the time of initial RRC connection setup when the terminal is switched from the idle state to the connected state, the component carrier that is camping on in the idle state is used as it is as the PCC. Further, the information extraction unit 109 generates SCC difference information based on the PCC, and outputs the difference information to the setting message generation unit 111.

In addition, when the information extraction unit 109 receives the determination content for establishing the RRC connection without performing carrier aggregation from the information processing unit 103, the information extraction unit 109 displays the setting information of the component carrier constituting the RRC connection as component carrier information. The setting information is read from the holding unit 107 and the setting information is output to the setting message generation unit 111.

The setting message generating unit 111 generates an RRC connection setting (RRC connection reconfiguration) message including the difference information generated by the information extracting unit 109. Note that the difference information is included in the RRC connection setup message only when starting carrier aggregation or changing the carrier configuration of a component carrier.

The transmission unit 113 includes data to be transmitted to the base station, a setting message for the terminal to communicate (for example, an RRC connection setting message), setting information for the terminal to perform reception quality measurement (measurement control), and the terminal actually A reference signal to be measured (reference 又 は symbol or reference 等 signal) or the like is transmitted via the antenna 115.

FIG. 5 is a flowchart showing a part of the operation of the base station according to the first embodiment when establishing an RRC connection. As shown in FIG. 5, the information processing unit 103 of the base station determines whether or not to perform carrier aggregation based on information received by the receiving unit 101 (step S101), and when performing carrier aggregation, proceeds to step S103. If not, go to step S115. In step S103, the component carrier determination unit 105 determines a used component carrier set. Next, the information extraction unit 109 extracts the component carrier setting information used as the PCC from the component carrier information holding unit 107 (step S105). Next, the information extraction unit 109 extracts the component carrier setting information used as the SCC from the component carrier information holding unit 107 (step S107).

Next, the information extraction unit 109 generates SCC difference information based on the PCC (step S109). Next, the setting message generation unit 111 generates an RRC connection setting message including difference information when performing carrier aggregation, and RRC including setting information of component carriers constituting the RRC connection when not performing carrier aggregation. A connection setting message is generated (step S111). Next, the transmission unit 113 transmits the RRC connection setting message generated in step S111 to the terminal (step S113). In step S115, the information extraction unit 109 extracts the setting information of the component carrier constituting the RRC connection from the component carrier information holding unit 107, and the setting message generation unit 111 generates an RRC connection setting message.

FIG. 6 is a block diagram illustrating an internal configuration of the terminal according to the first embodiment. As illustrated in FIG. 6, the terminal according to the first embodiment includes a reception unit 151, a setting message processing unit 153, a carrier aggregation setting unit 155, a setting completion message generation unit 157, and a transmission unit 159.

The reception unit 151 includes data transmitted from the base station, a setting message for the terminal to perform communication (for example, an RRC connection setting message), setting information for the terminal to perform reception quality measurement (measurement control), and the terminal actually A reference signal (reference symbol or reference signal) to be measured is received via the antenna 161.

The setting message processing unit 153 processes the RRC connection setting message received by the receiving unit 151 and outputs an instruction or the like to the carrier aggregation setting unit 155 or the setting completion message generating unit 157. The setting message processing unit 153 determines that the carrier aggregation is performed when the difference information described above is included in the RRC connection setting message, and notifies the carrier aggregation setting unit 155 of the determination result. Also, the setting message processing unit 153 determines that carrier aggregation is not performed when the difference information is not included in the RRC connection setting message, and notifies the setting completion message generation unit 157 of the determination result.

The carrier aggregation setting unit 155 operates when the setting message processing unit 153 determines that carrier aggregation is performed, and includes a component carrier information holding unit 171, a PCC setting unit 173, and an SCC setting unit 175. The component carrier information holding unit 171 holds setting information such as frequency information, band information, radio resource setting information, and physical channel setting information of the component carrier used by the terminal included in the RRC connection setting message transmitted from the base station. To do.

The PCC setting unit 173 sets the primary component carrier (PCC) instructed by the base station with reference to the information held in the component carrier information holding unit 171. The SCC setting unit 175 sets the secondary component carrier (SCC) instructed by the base station with reference to the information held in the component carrier information holding unit 171. The SCC setting information held by the component carrier information holding unit 171 is difference information with respect to the PCC, and the SCC setting unit 175 sets the SCC with reference to both the SCC setting information and the PCC setting information. .

When the setting by the PCC setting unit 173 and the SCC setting unit 175 of the carrier aggregation setting unit 155 is completed, the setting completion message generation unit 157 generates a setting completion message. The setting completion message generation unit 157 also generates a setting completion message even when the setting message processing unit 153 is notified of the determination result that the carrier aggregation is not performed.

The transmission unit 159 transmits information such as data to be transmitted to the terminal, a setting completion message, terminal performance information, and reception quality measurement results via the antenna 161.

FIG. 7 is a flowchart showing a part of the operation of the terminal according to the first embodiment when establishing an RRC connection. As shown in FIG. 7, the receiving unit 151 of the terminal receives an RRC connection setup message (step S201). Next, the setting message processing unit 153 determines whether or not to perform carrier aggregation depending on whether or not the above-described difference information is included in the RRC connection setting message received in step S201 (step S203). . If carrier aggregation is performed as a result of the determination, the process proceeds to step S205, and if not, the process proceeds to step S213.

In step S205, the PCC setting unit 173 for carrier aggregation sets the PCC. Next, the carrier aggregation PCC setting unit 173 sets the SCC with reference to the PCC setting information (step S207). When the setting of each component carrier is completed, the setting completion message generating unit 157 creates a setting completion message (step S209). Next, the transmission unit 159 transmits the setting completion message generated in step S209 to the base station (step S211). In step S213, the terminal sets a component carrier, and the setting completion message generation unit 157 generates a setting completion message.

As described above, in the present embodiment, the information about the SCC included in the RRC connection setting message transmitted from the base station to the terminal is SCC difference information (delta configuration) based on the PCC. Therefore, the amount of signaling related to the addition or change of component carriers can be minimized.

Next, although there is no change in the component carrier set, generation of difference information (delta configuration) when the PCC and SCC settings are changed in the component carrier set in use will be described. FIG. 29 is a diagram illustrating an example of PCC and SCC changes in a component carrier set in use.

In the example shown in FIG. 29, before the setting change, the terminal uses a pair component carrier of (CC1, CCa) as the PCC and two pair component carriers of (CC2, CCb) and (CC3, CCc) as the SCC. I use it. Here, the base station changes the pair component carrier of (CC2, CCb) used as SCC to PCC, changes the pair component carrier of (CC1, CCa) used as PCC to SCC, and The terminal notifies an RRC connection setting message instructing to change the setting of SCC (CC3, CCc).

The base station generates difference information on the setting of the pair component carriers (CC2, CCb) to be newly used as the PCC based on the setting of the original PCC (CC1, CCa), and similarly, the base PCC (CC1, CCa) Based on the setting of CCa), difference information of the setting of the pair component carrier (CC1, CCa) to be newly used as the SCC is generated. In addition, for SCC (CC3, CCc), the base station generates only the newly changed setting as difference information with reference to the setting of the currently used SCC (CC3, CCc). In addition, when a base station uses a component carrier under the management of the base station other than a component carrier currently used as a PCC or SCC as a PCC, the base station newly uses a new PCC based on the setting of the original PCC. The difference information of the setting of the pair component carrier used as is generated.

In this way, when changing the setting of the component carrier set being used, the base station generates only the newly changed pair component carrier setting as difference information with reference to the currently used setting. Therefore, the amount of signaling related to the change of the component carrier can be minimized.

Note that the PCC setting information and the additional SCC setting information transmitted from the base station to the terminal may be notified to the terminal by one signaling (RRC connection setting message), or may be notified by different signaling. When the PCC setting information and the additional SCC setting information are notified by different signaling, for example, in the RRC connection setting message shown in FIG. 1, only the connection related to the PCC is set, and the RRC connection setting completion message from the terminal Is received by the base station, the base station again transmits an RRC connection setup message including the setup information of the additional SCC to the terminal. In this case, carrier aggregation is started when the terminal receives an RRC connection setting message including setting information of the additional SCC.

Note that, when the base station instructs the terminal to perform carrier aggregation, whether or not to perform difference notification based on the PCC may be switched by a 1-bit flag. Specifically, a 1-bit flag is newly introduced in the RRC connection setup message. When the flag is set, the terminal performs delta configuration (delta configuration) based on the PCC, otherwise, for a parameter that does not include a value, the terminal uses the current value as it is. Or, an operation such as deleting a value currently used is performed. Furthermore, switching whether to perform delta configuration is not only performed with a 1-bit flag for all parameters, but a new 1-bit flag may be introduced for each parameter, and switching may be performed in parameter units.

(Second Embodiment)
While the base station and the terminal are communicating, the primary component carrier (PCC) may be changed as the terminal moves. However, it is suitable for reducing the amount of signaling between the case of PCC change in the same base station (intra-eNB) and the case of PCC change accompanying handover to a different base station (inter-eNB). The signaling method is different.

In the second embodiment, attention is paid to the fact that the security information that can be included in the RRC connection setup message transmitted from the base station to the terminal occurs only at the time of handover to a different base station. Therefore, in this embodiment, the amount of signaling related to the addition or change of the component carrier is minimized by selecting information to be transmitted to the terminal by the base station depending on whether the PCC is changed with handover and the situation such as the change of the SCC. To the limit.

FIG. 8 is a diagram illustrating a configuration example of an RRC connection setup (RRC Connection Reconfiguration) message transmitted from the base station to the terminal. Conventionally, the RRC connection setting message transmitted from the base station to the terminal in accordance with the handover includes information such as “mobility control information (MobilityControlInfo)”, “security setting (SecurityConfigHO)”, and “radio resource individual setting (RadioResourceConfigDedicated)”. It is. In the present embodiment, regardless of the presence or absence of handover, the RRC connection setting message at the time of PCC change includes setting information of “PCC related parameters” in the mobility control information as shown in FIG.

Also, in this embodiment, “additional component carrier setting” is provided in the RRC connection setting message as a new information element at the time of setting (adding, deleting or changing) the SCC. The additional component carrier setting is an item for notifying SCC setting information, and has a component carrier list including component carrier ID (identification information) and setting information for each of the downlink and uplink. The component carrier setting information includes SCC-related parameters.

When the PCC is changed, difference information from the changed PCC setting based on the setting of the PCC currently used by the terminal is included in the mobility control information of the RRC connection setting message. Further, when setting the SCC, the additional component carrier setting is included in the RRC connection setting message, and the component carrier to be set is indicated by the ID of the component carrier list. The SCC setting represented by the additional component carrier setting is represented by component carrier difference information based on the setting of the PCC currently used by the terminal when there is no PCC change and when the PCC is changed. Is done.

When PCC change and SCC setting are performed simultaneously, the RRC connection setting message includes both mobility control information and additional component carrier setting. At this time, the mobility control information includes difference information from the new PCC setting based on the setting of the PCC currently in use, and the additional component carrier setting includes the SCC setting based on the new PCC setting. Difference information is included.

Also, in the case of a handover to a different base station (inter-eNBＲHO), the RRC connection setting message includes “security setting”. The terminal that has received the RRC connection setting message deletes the settings of all the component carriers currently in use even if there is no instruction to delete the SCC by the additional component carrier setting. On the other hand, when there is no change of the base station, “security setting” is not included in the RRC connection setting message.

FIG. 9 is a diagram illustrating signaling between a terminal and a base station at the time of handover. In the following description, as shown in FIG. 10, the terminal before the handover performs carrier aggregation using the component carriers CC1, CC2, CCa, and CCb, and the terminal after the handover performs the component carriers CC3, CC4, CCc, Assume that carrier aggregation is performed using CCd.

The terminal reports the measurement results obtained by measuring the reception quality of neighboring cells to the currently connected source base station. Based on the reception quality measurement result from the terminal, the source base station determines whether or not to perform handover for switching the connection to a cell with better reception quality. When performing a handover, the source base station sends a handover request to the target base station that is the handover destination. In response to the handover request from the source base station, the target base station determines whether or not the terminal handover can be accepted based on the load status of the local station. If the target base station can accept the handover, the target base station creates a handover command message for prompting the terminal to perform the handover, and transmits a handover request response message including the handover command message to the source base station. When a response message to the handover request is returned from the target base station, the source base station sends a handover command message included in the message to the terminal.

At this time, in the case of inter-base station handover (inter-eNB HO) moving from the source base station to the target base station as shown in FIG. 10, the target base station is a message for instructing to change the security information “security setting”. (SecurityConfigHO) "is included in the handover command message. The terminal receives the handover command message, and when the “security setting” is included in the message, the terminal deletes all the settings of the currently used SCC (CC2, CCb).

Further, the source base station transmits a handover request message including setting information of PCC (CC1, CCa) currently used by the terminal to the target base station. The target base station determines a component carrier set to be used by the target base station for communication with the terminal, and sends the setting information to the terminal through the source base station by a handover command. For example, when a pair of component carriers CC3 and CCc is used as a PCC and a pair of component carriers CC4 and CCd is used as an SCC in the target base station, the setting information is included in the handover command message and sent to the terminal. Note that the PCC pair component carrier used by the target base station is determined by the source base station based on the reception quality measurement result from the terminal, and the SCC pair component carrier used by the target base station is determined by the target base station. Is done. However, the target base station may change the PCC pair component carrier determined by the source base station. The source base station includes the number of SCCs used by the terminal at the source base station and the SCC candidates based on the reception quality measurement results in the handover request message as information for the target base station to determine the SCC. Also good. In addition, the target base station may newly select a PCC again from SCC candidates.

The target base station uses the PCC (CC1, CCa) setting used by the source base station for communication with the terminal included in the handover request message as a reference, and the target base station newly starts the PCC for communication with the terminal. Difference information for setting the pair component carriers (CC3, CCc) used as Further, the target base station uses a pair component carrier (CC4, CCd) that the target base station newly uses as an SCC in communication with the terminal, based on the setting of the pair component carrier (CC3, CCc) that is newly used as the PCC. ) Difference information is generated.

If the setting information of the component carrier set used in the target base station is included in the handover command message, the terminal deletes the setting of the component carrier set used in the source base station and then sets a new component carrier set. Set up.

The terminal transmits a RACH preamble message for establishing synchronization with the target base station B to the target base station according to the setting information of the component carriers CC3 and CCc instructed as PCC from the target base station. The target base station sends uplink resource allocation and timing information as a response (RACH response) to the RACH preamble message from the terminal. When synchronization establishment and component carrier set setting are completed between the terminal and the target base station, the terminal transmits a handover completion message to the target base station.

FIG. 11 is a block diagram illustrating an internal configuration of the base station according to the second embodiment. The same or equivalent parts as those of the base station of the first embodiment shown in FIG. As illustrated in FIG. 11, the base station of the second embodiment further includes a handover determining unit 201 in addition to the components included in the base station of the first embodiment.

The handover determining unit 201 determines whether or not handover is necessary based on the reception quality measurement result sent from the terminal, and determines the handover destination cell when it is determined to perform handover. The handover determining unit 201 outputs the determined content to the information extracting unit 109 and the setting message generating unit 111.

The component carrier determination unit 105 determines a used component carrier set after the handover. The information extraction unit 109 extracts information necessary for the component carrier used by the terminal from the component carrier information holding unit 107 based on the determination content by the handover determination unit 201 and the used component carrier set determined by the component carrier determination unit 105. . If the content determined by the component carrier determination unit 105 means that the PCC has been changed, the information extraction unit 109 extracts the setting information of the PCC currently used by the terminal and the setting information of the new PCC from the component carrier information holding unit 107. Then, the difference information is generated, and the difference information is output to the setting message generation unit 111.

In addition, when the determination content of the component carrier determination unit 105 means SCC setting (addition, deletion, or change), the information extraction unit 109 extracts the PCC setting information and the SCC setting information from the component carrier information holding unit 107. Then, the difference information is generated, and the difference information is output to the setting message generation unit 111. At this time, if a PCC change occurs simultaneously, the new PCC setting information is used as a reference for the difference information, and the information extraction unit 109 also outputs the PCC setting information to the setting message generation unit 111. On the other hand, when only SCC is set (added, deleted, or changed), the setting information of the PCC currently used by the terminal is used as a reference for the difference information.

The setting message generating unit 111 generates a setting message to be sent to the terminal according to the information input from the information extracting unit 109 and the instruction input from the handover determining unit 201. When the PCC setting information is input from the information extraction unit 109, the setting message generation unit 111 includes the information as a PCC related parameter of the mobility control information in the RRC connection setting message. When difference information is input from the information extraction unit 109, the information is included in the RRC connection setting message as additional component carrier setting information. Note that the setting message generator 111 includes the security setting information in the RRC connection setting message when an instruction for inter-base station handover (inter-eNB HO) is input from the handover determining unit 201.

FIG. 12 is a flowchart showing a part of the operation of the base station according to the second embodiment. As shown in FIG. 12, it is determined whether or not to change the PCC based on whether or not handover is required by the handover determining unit 201 (step S301). If the handover is to be performed, the PCC needs to be changed, and the process proceeds to step S303. If the handover is not performed, the PCC is not changed and the process proceeds to step S311. In step S303, the information extraction unit 109 generates difference information of the new PCC based on the setting of the PCC currently used by the terminal. Next, the setting message generation unit 111 includes the difference information as mobility control information in the RRC connection setting message (step S305).

Next, the setting message generation unit 111 determines whether the determination content of the handover determination unit 201 is a handover to a different base station (inter-eNBeHO) (step S307), and performs a handover to a different base station. In this case, the process proceeds to step S309, and in the case of handover (intra-eNBinHO) within the same base station, the process proceeds to step S311. In step S309, the setting message generation unit 111 includes security setting information in the RRC connection setting message.

In step S311, it is determined whether or not SCC settings (addition, deletion, or change) are included in the content determined by the component carrier determination unit 105. When the SCC setting is included, the information extraction unit 109 generates difference information of the SCC setting information based on the new PCC setting information (step S313), and the setting message generation unit 111 adds the difference information. The component carrier setting is included in the RRC connection setting message (step S315). In addition, when there is no change of PCC and only the setting of SCC is performed, the reference of the difference information of SCC is the setting of PCC currently used by the terminal. Next, the transmission unit 113 transmits an RRC connection setting message to the terminal (step S317).

The operation of the source base station and the target base station when performing handover (inter-eNB-HO) between base stations in the second embodiment will be described in detail with reference to FIGS. FIG. 30 is a flowchart showing a part of the operation of the source base station in the second embodiment when performing handover (inter-eNB HO) between base stations. FIG. 31 is a flowchart showing a part of the operation of the target base station in the second embodiment when performing handover between base stations (inter-eNB 間 の HO). In FIG. 31, the same reference numerals are assigned to steps common to FIG.

As shown in FIG. 30, the source base station receives the reception quality measurement result sent from the terminal (step S701). Next, the source base station determines whether or not to perform handover (inter-eNB HO) between base stations based on the reception quality measurement result (step S703). If the handover is performed, step S705 is performed. If not, the process proceeds to step S713.

In step S705, the source base station selects a PCC from the component carrier set used by the terminal and extracts its setting information. Next, the source base station creates a handover request message including PCC setting information (step S707). At this time, the source base station includes information (for example, physical cell ID (PCI), carrier frequency (dl-CarrierFreq), etc.) indicating the PCC used by the target base station for communication with the terminal in the handover request message. Also good. Further, as information for determining the SCC at the target base station, the number of SCCs used by the terminal at the source base station, SCC candidates based on the reception quality measurement result, and the like may be included. Next, the source base station transmits the handover request message created in step S707 to the target base station (step S709).

Next, the source base station receives the handover request response message including the RRC connection setup message transmitted from the target base station shown in FIG. 31 described later (step S711). Next, the source base station transmits an RRC connection setup message included in the handover request response message to the terminal when a handover (inter-eNB HO) is performed between the base stations (step S713).

As shown in FIG. 31, the target base station receives a handover request message from the source base station (step S801). Next, the target base station generates difference information of the new PCC based on the setting of the PCC currently used by the terminal (step S303). Next, the target base station includes the difference information as mobility control information in the RRC connection setup message (step S305).

Next, the target base station determines whether it is necessary to set SCC as an additional component carrier (step S311). If it is determined that SCC setting is required, the process proceeds to step S313, where it is determined that it is not necessary. If YES, the process proceeds to step S803. At this time, the SCC set selected by the target base station may be selected from the SCC candidates indicated in the handover request message by the source base station. In step S313, the target base station generates SCC difference information based on the setting of the new PCC. Next, the target base station includes the difference information as an additional component carrier setting in the RRC connection setting message (step S315). Next, the target base station creates an RRC connection message including security settings (step S803). Next, the target base station creates a handover request response message including this RRC connection message and transmits it to the source base station (step S805).

The terminal of the second embodiment has the same configuration as the terminal of the first embodiment. FIG. 13 is a flowchart illustrating a part of the operation of the terminal according to the second embodiment. As illustrated in FIG. 13, the receiving unit 151 of the terminal receives an RRC connection setup message (step S401). Next, the setting message processing unit 153 determines whether mobility control information is included in the RRC connection setting message received in step S401 (step S403). If the mobility control information is included, the setting message processing unit 153 proceeds to step S405. If mobility control information is not included, the process proceeds to step S411. In step S405, the setting message processing unit 153 determines whether or not the security setting is included in the RRC connection setting message. If the security setting is included, the process proceeds to step S407, and if the security setting is not included. The process proceeds to step S409.

In step S407, the carrier aggregation setting unit 155 deletes the settings of all component carriers currently in use. Next, in step S409, the carrier aggregation setting unit 155 then sets the component carrier described in the mobility control information as a new PCC.

Next, the setting message processing unit 153 determines whether or not the additional component carrier setting is included in the RRC connection setting message (step S411). If the additional component carrier setting is included, the process proceeds to step S413. If the component carrier setting is not included, the process ends. In step S413, the carrier aggregation setting unit 155 sets the SCC with reference to the PCC setting information according to the additional component carrier setting. When the setting of each component carrier is completed, the setting completion message generating unit 157 creates a setting completion message (step S209). Next, the transmission unit 159 transmits the setting completion message generated in step S209 to the base station (step S211).

The 3GPP standard ASN.3 of the RRC connection setup message generated by the setup message generator 111 shown in FIG. FIG. 14 to FIG. 23 show message structures in one format. Note that the “Need ON” notation shown in FIGS. 14 to 23 indicates that the parameter is optional, and if the value for the parameter is not included in the message, the terminal does not perform any special operation and is currently set. Continue to use the value that is being used. Further, “Need OP” notation indicates that the parameter is optional, and if the value for the parameter is not included in the message, the terminal performs the specified operation.

In addition, “Need OR” notation indicates that the parameter is optional, and if there is no value for the parameter in the message, the terminal stops using the currently set value and stores it in the terminal. Delete the value that is present. Also, “Need OA” notation indicates that the parameter is optional, and if the value for the corresponding parameter is not included in the message, the terminal applies the value of the parameter set in the PCC. Further, “Cond” notation indicates that a value is entered in the corresponding parameter under a certain condition. For example, “Con HO” indicates that a value is entered in the corresponding parameter at the time of handover.

14 and 15 show the ASN.3 of the RRC connection setting message (RRC connection reconfiguration message). It is an example of a message structure by 1 format. The PCC related information is included in mobility control information (mobilityControlInfo), and the SCC related information is included in additional component carrier setting (AdditionalCCCOnfig).

FIG. 16 shows ASN.3 of mobility control information (mobilityControlInfo). It is an example of a message structure by 1 format. In the example illustrated in FIG. 16, the PCC ID includes a PCC ID (pccIdentity). Note that “Cond CaAg” notation indicates that the corresponding parameter is optional and a value is entered under the condition of carrier aggregation.

Fig. 17 shows the ASN.1 of the additional component carrier setting (AdditionalCCCOnfig). It is an example of a message structure by 1 format. The instruction to delete the downlink component carrier is performed by “DLCCToRemoveList”, and the instruction to add / modify the downlink component carrier is performed by “DLCCToAddModList”. In addition, an instruction to delete an uplink component carrier is performed by “ULCCToRemoveList”, and an instruction to add / change an uplink component carrier is performed by “ULCCToAddModList”. For example, when deleting a downlink component carrier, the ID of the component carrier to be deleted is indicated in “DLCCToRemoveList”.

FIG. 18 shows ASN.1, which notifies the setting of addition / change of the downlink component carrier used by the terminal. It is an example of a message structure by 1 format. The message shown in FIG. 18 is referred to from “DLCCToAddModList” in FIG. “DLCCToAddModList” is composed of a set of downlink component carrier IDs (DLCCId) and detailed parameters (DLCCConfig) to be added / modified. The common component carrier ID is used between the base station and the terminal, and the base station instructs the terminal using the component carrier ID in the “DLCCToAddModList” for the downlink component carrier to be added / modified.

Among the parameters related to the downlink component carrier, when a value for the corresponding parameter is not included in the message, the value ("Need OA") to which the value of the parameter set in the PCC is applied is the bandwidth (dl -Bandwidth), system frame number (systemFrameNumber), frequency band index (freqBandIndicator), scheduling information list (SchedulingInfoList), system information window width (si-WindowLength), broadcast control channel setting (bcch-Config), paging control channel setting ( pcch-Config), physical downlink common channel setting (pdsch-ConfigCommon), additional spectrum emission (additionalSpectrumEmission), antenna information (antennaInfo), and the like. These parameters have a high possibility of using a common value in the component carrier set to be carrier-aggregated, and it is considered that the effect of reducing signaling is high by performing delta configuration based on PCC.

Parameters that need to be set for each downlink component carrier include the ID (PDCCHmonitoringCC) of the downlink component carrier that transmits the physical control channel (PDCCH) that instructs data transmission to the downlink component carrier, the carrier frequency (dl -CarrierFreq) and system information change information (systemInfoValueTag).

FIG. 19 shows ASN.1, which notifies the setting of addition / change of the uplink component carrier used by the terminal. It is an example of a message structure by 1 format. The message in FIG. 19 is referred to from “UCCToAddModList” in FIG. “UCCToAddModList” is composed of a set of ID (ULCCId) and detailed parameters (ULCCConfig) of uplink component carriers to be added / changed. A common component carrier ID is used between the base station and the terminal, and the base station instructs the terminal using the component carrier ID in the “ULCCToAddModList” for the uplink component carrier to be added / changed.

Among the parameters related to uplink component carriers, those that perform differential notification based on PCC ("Need OA") include bandwidth (ul-Bandwidth), frequency band indicator (freqBandIndicator), physical uplink common channel setting (Pusch-ConfigCommon), uplink reference signal setting (sounding RS-UL-ConfigCommon), uplink power control setting (uplinkPowerControlCommon), and cyclic prefix length (ul-CyclicPrefixLength). These parameters have a high possibility of using a common value in the component carrier set to be carrier-aggregated, and it is considered that the effect of reducing signaling is high by performing delta configuration based on PCC.

Parameters that need to be set for each uplink component carrier include carrier frequency (ul-CarrierFreq), system information change information (systemInfoValueTag), maximum transmission power of the terminal (p-Max), and uplink power control setting (tpc -PDCCH-ConfigPUSCH).

As described above, in this embodiment, since mobility control information and security settings included in an existing RRC connection setup message are used, an increase in the number of messages when changing the PCC can be minimized. Further, by selecting information to be sent in the RRC connection setup message according to the situation such as PCC change, SCC change, or handover, the signaling amount related to the component carrier setting can be minimized.

Also, at the time of handover between base stations (inter-eNB） HO), new PCC difference information is generated based on the setting of the PCC currently used by the terminal, and the SCC difference information based on the setting of the new PCC is generated. In order to generate, only the setting information of the PCC in use needs to be transmitted from the source base station to the target base station. Therefore, the amount of signaling transmitted / received at the time of handover between base stations (inter-eNB HO) can be minimized.

Note that the deletion of the settings of all component carriers is not determined by the terminal depending on whether or not the security setting is included in the RRC connection setting message, but the deletion of the settings of all component carriers is permitted or permitted in the handover command message. The base station may explicitly indicate the state of the 1-bit information including the 1-bit information not to be transmitted.

Note that even if a radio connection failure (Radio Link Failure) occurs during carrier aggregation and the terminal performs reconnection operation (RRC connection Reestablishment), the terminal implicitly deletes the SCC setting. At this time, even if the terminal deletes the SCC setting after sending a reconnection request (RRC Connection Reestablishment Request) message or a reconnection completion (RRC Connection Reestablishment Complete) message, a radio connection failure (Radio Link Failure) After the occurrence, it may be performed at an arbitrary timing of the terminal, or may be triggered by receiving a reconnection (RRC Connection Reestablishment) message from the base station.

Information used for terminal identification (short MAC-I) in information for reconnection (Reestablishment Info) included in a handover request message sent from the source base station to the target base station at the time of handover. ) And the identification information (short MAC-I) used by the terminal during reconnection are the same. For example, the physical cell ID (PCI) of the source base station or the physical cell ID (PCI) used for generating the security key (key_eNB) is used.

(Third embodiment)
In the first embodiment and the second embodiment described above, the addition or change of the component carrier is performed using the difference information (delta configuration) of the component carrier based on the PCC. However, PCC is not always optimal as a reference for difference information. In the third embodiment, the component carrier setting is changed by setting the component carrier (hereinafter referred to as “reference component carrier”) as a reference of the difference information to a component carrier having a similar situation such as the same frequency band. The amount of signaling can be reduced.

FIG. 24 is a block diagram illustrating an internal configuration of the base station according to the third embodiment. The same or equivalent parts as those of the base station of the second embodiment shown in FIG. As illustrated in FIG. 24, the base station of the third embodiment further includes a reference component carrier selection unit 301 in addition to the components included in the base station of the second embodiment.

The component carrier determination unit 105 determines a component carrier set to be used, a component carrier to be a PCC, and the like based on terminal performance information, reception quality measurement results, and the like.

The reference component carrier selection unit 301 selects a reference component carrier from the used component carrier set determined by the component carrier determination unit 105. The reference component carrier selection unit 301 may select a reference component carrier when selecting a PCC or when selecting a plurality of reference component carriers from a component carrier set. In the latter case, the reference component carrier is selected for each set, such as for each same frequency band (for example, 2 GHz and 800 MHz), for each component carrier having the same synchronization timing between the terminal and the base station, or for each component carrier having the same cell size. The reference component carrier selection unit 301 selects a reference component carrier according to, for example, the reception quality of the terminal or the load status of the radio resource being used.

The information extraction unit 109 generates component carrier difference information based on the reference component carrier based on the used component carrier set determined by the component carrier determination unit 105 and the reference component carrier selected by the reference component carrier selection unit 301. To do.

FIG. 25 is a flowchart showing a part of the operation of the base station according to the third embodiment. The same or equivalent parts as those included in the flowchart of the base station according to the second embodiment shown in FIG. In the present embodiment, if it is determined in step S311 that the SCC setting (addition, deletion, or change) is included in the determination content by the component carrier determination unit 105, the process proceeds to step S501. In step S501, the reference component carrier selection unit 301 selects a reference component carrier from the used component carrier set. Next, it is determined whether or not the reference component carrier selected in step S501 is only PCC (step S503).

If the reference component carrier selected in step S501 is only PCC, the process proceeds to step S313, and the information extraction unit 109 generates difference information of the SCC setting information based on the new PCC setting information. On the other hand, when the reference component carrier selected in step S501 is set in addition to the PCC, the information extraction unit 109 generates difference information from the reference component carrier for each SCC (step S505), and a setting message generation unit 111 includes the difference information and the reference component carrier setting information as additional component carrier settings in the RRC connection setting message.

Note that the reference component carrier setting information is, for example, a component carrier ID. In addition, as an example of the reference component carrier indication method in the configuration message generated by the configuration message generation unit 111 included in the base station of the present embodiment, for example, as shown in FIG. 20 and FIG. 21, the downlink component carrier and the uplink This is a method of notifying the reference component carrier ID (baseCC) in the component carrier addition / change information (“DLCCToAddMod”, “ULCCToAddMod”). As another example, as shown in FIG. 22 and FIG. 23, the group ID (groupID) and the addition / change information (“DLCCToAddMod”, “ULCCToAddMod”) of the downlink component carrier and the uplink component carrier There is also a method for indicating the main component carrier (groupAnchorCC) in the group.

FIG. 26 is a block diagram illustrating an internal configuration of a terminal according to the third embodiment. The same or equivalent parts as those of the terminals of the first and second embodiments shown in FIG. As illustrated in FIG. 26, the terminal according to the third embodiment further includes a reference component carrier determination unit 371 in the carrier aggregation setting unit 155 in addition to the components included in the terminal according to the second embodiment.

The reference component carrier determination unit 371 determines the reference component carrier when setting the SCC from the information of the setting message processed by the setting message processing unit 153. The SCC setting unit 175 sets the SCC instructed from the base station according to the information of the setting message processed by the setting message processing unit 153 and the reference component carrier determined by the reference component carrier determination unit 371. At that time, the SCC setting unit 175 sets the SCC with reference to the reference component carrier.

FIG. 27 is a flowchart showing a part of the operation of the terminal according to the third embodiment. The same or equivalent parts as the steps included in the flowchart of the base station of the second embodiment shown in FIG. In the present embodiment, when the setting message processing unit 153 determines that the additional component carrier setting is included in the RRC connection setting message in step S411, it is determined whether or not the reference component carrier is only PCC (step S601). . If the reference component carrier is only the PCC, the process proceeds to step S413, and the SCC setting unit 175 sets the SCC with reference to the PCC setting information and the difference information. On the other hand, if the reference component carrier is set to other than the PCC, the process proceeds to step S603, and the SCC setting unit 175 refers to the specified component carrier setting information and the difference information based on the specified component carrier. To set the SCC.

As described above, in this embodiment, when a component carrier is added or changed, signaling for changing the setting of the component carrier is performed by making the reference component carrier a component carrier having a similar frequency band or the like. The amount can be reduced.

In addition, when a plurality of reference component carriers are set, it is not necessary to explicitly indicate the component carrier based on the PCC by the component carrier ID or the like. That is, when the reference component carrier is not explicitly indicated, the terminal determines that the PCC is the reference component carrier.

In addition, when there is only one component carrier in the group of component carriers, when adding a new component carrier to the group, the terminal does not require an explicit instruction from the base station. The carrier may be determined as the reference component carrier. In addition, when there are two component carriers in a certain component carrier group and the reference component carrier is deleted, the terminal can perform the remaining component carriers even if there is no explicit instruction from the base station. May be determined as a reference component carrier.

In addition, when a group of component carriers is set for each frequency band, the group of component carriers may be notified and determined based on the bandwidth (ul-Bandwidth, dl-Bandwidth) instead of the group ID.

In each of the above embodiments, the case where the present invention is configured by hardware has been described as an example, but the present invention can also be realized by software.

Further, each functional block used in the description of each of the above embodiments is typically realized as an LSI that is an integrated circuit. These may be individually made into one chip, or may be made into one chip so as to include a part or all of them. Although referred to as LSI here, it may be referred to as IC, system LSI, super LSI, or ultra LSI depending on the degree of integration.

Further, the method of circuit integration is not limited to LSI, and implementation with a dedicated circuit or a general-purpose processor is also possible. An FPGA (Field Programmable Gate Array) that can be programmed after manufacturing the LSI or a reconfigurable processor that can reconfigure the connection and setting of circuit cells inside the LSI may be used.

Furthermore, if integrated circuit technology that replaces LSI emerges as a result of advances in semiconductor technology or other derived technology, it is naturally also possible to integrate functional blocks using this technology. Biotechnology can be applied.

Although the antennas 115 and 161 have been described in the above embodiment, the present invention can be similarly applied to antenna ports. An antenna port refers to a logical antenna composed of one or a plurality of physical antennas. That is, the antenna port does not necessarily indicate one physical antenna, but may indicate an array antenna or the like composed of a plurality of antennas. For example, in LTE (Long Term Evolution), it is not defined how many physical antennas an antenna port is composed of, but is defined as a minimum unit in which a base station can transmit a different reference signal (Reference signal). An antenna port may be defined as a minimum unit for multiplying a weight of a precoding vector.

Although the present invention has been described in detail and with reference to specific embodiments, it will be apparent to those skilled in the art that various changes and modifications can be made without departing from the spirit and scope of the invention.

This application is based on a Japanese patent application filed on March 31, 2010 (Japanese Patent Application 2010-083011) and a Japanese patent application filed on April 30, 2010 (Japanese Patent Application 2010-105272). Incorporated herein by reference.

The radio communication base station, radio communication apparatus, and radio communication system according to the present invention are useful as a communication apparatus, a system, or the like by simultaneously using each component carrier of a plurality of communication cells by carrier aggregation.

101 receiving unit 103 information processing unit 105 component carrier determining unit 107 component carrier information holding unit 109 information extracting unit 111 setting message generating unit 113 transmitting unit 151 receiving unit 153 setting message processing unit 155 carrier aggregation setting unit 157 setting completion message generating unit 159 Transmission unit 171 Component carrier information holding unit 173 PCC setting unit 175 SCC setting unit 201 Handover determination unit 301 Reference component carrier selection unit 371 Reference component carrier determination unit

Claims (16)

A wireless communication base station capable of communicating with a wireless communication device using each component carrier of a plurality of communication cells simultaneously,
A receiving unit for receiving information transmitted from the wireless communication device;
The wireless communication apparatus using the component carrier set that includes the first component carrier used as a reference carrier and at least one second component carrier used simultaneously with the first component carrier by processing information received by the receiving unit Component carrier determining unit that determines a component carrier set to be used when it is determined that the carrier configuration of the component carrier set is changed during communication with the wireless communication device using the component carrier set. When,
The second / first inter-carrier difference information, which is difference information with respect to the setting information of the second component carrier, based on the setting information of the first component carrier included in the used component carrier set determined by the component carrier determining unit. A difference information generation unit to generate;
A setting message generator for generating a setting message including the second / first carrier difference information;
A transmission unit for transmitting the setting message to the wireless communication device;
A wireless communication base station comprising: The radio communication base station according to claim 1,
A component carrier information holding unit that holds setting information of each component carrier of the plurality of communication cells managed by the radio communication base station;
The difference information generation unit extracts the setting information of the first component carrier and the setting information of the second component carrier included in the used component carrier set from the component carrier information holding unit. Bureau. The radio communication base station according to claim 1 or 2,
At least some of the second component carriers included in the used component carrier set determined by the component carrier determining unit are used by changing the setting of the second component carrier included in the used component carrier set before the component carrier change. If
The difference information generation unit is difference information between the second and second carriers, which is difference information with respect to the setting information of the second component carrier after the change of the component carrier based on the setting information of the second component carrier before the change of the component carrier. Generate difference information,
The radio communication base station, wherein the message generator generates a setting message including the second / second inter-carrier difference information. The radio communication base station according to claim 1 or 2,
Based on the information received by the receiving unit, a handover determining unit that determines whether or not handover is necessary and determines a handover destination communication cell when it is determined to perform handover,
When the handover determining unit determines to perform handover,
The component carrier determination unit determines a used component carrier set after handover,
When the first component carrier included in the used component carrier set before the handover is different from the first component carrier included in the used component carrier set after the handover, the difference information generation unit sets the first component carrier before the handover. Generating first / first inter-carrier difference information that is difference information from the setting information of the first component carrier after the handover based on the information;
The radio communication base station, wherein the configuration message generation unit generates a configuration message including the first / first inter-carrier difference information. The wireless communication base station according to claim 4, wherein
When at least a part of the second component carrier included in the used component carrier set after the handover is different from the second component carrier included in the used component carrier set before the handover,
The radio communication base station, wherein the difference information generation unit uses the setting information of the first component carrier after the handover as a reference when generating the second / first carrier difference information. The wireless communication base station according to claim 4 or 5,
When the radio communication base station and the radio communication base station that manages the handover destination communication cell determined by the handover determining unit are different,
The wireless communication base station, wherein the setting message generation unit includes predetermined information in the setting message. The wireless communication base station according to claim 4 or 5,
When the radio communication base station and the radio communication base station that manages the handover destination communication cell determined by the handover determining unit are different,
The difference information generation unit
Receiving setting information of the first component carrier before handover from a radio communication base station that manages the communication cell before handover;
The radio communication base station, wherein the first / first inter-carrier difference information and the second / first inter-carrier difference information are generated based on the received first component carrier setting information. The radio communication base station according to any one of claims 1 to 7,
The wireless communication base station, wherein the first component carrier is a primary component carrier. The radio communication base station according to any one of claims 1 to 7,
A radio communication base station comprising a reference component carrier selection unit that selects at least one of the first component carriers from the used component carrier set. The radio communication base station according to claim 9, wherein
The wireless communication base station, wherein the reference component carrier selection unit selects the first component carrier from a plurality of sets of component carriers having similar conditions in the used component carrier set. A wireless communication apparatus capable of communicating with the wireless communication base station by using each component carrier of a plurality of communication cells managed by the wireless communication base station according to any one of claims 1 to 10,
A receiving unit for receiving a setting message transmitted from the wireless communication base station;
A component carrier setting unit configured to set at least one component carrier based on component carrier setting information included in the setting message received by the receiving unit;
The component carrier setting unit
When the setting message includes second / first carrier difference information that is difference information with respect to the setting information of the second component carrier with reference to the setting information of the first component carrier, A wireless communication apparatus, wherein the second component carrier is set with reference to setting information and the second / first carrier difference information. The wireless communication device according to claim 11,
The component carrier setting unit
When the setting message includes first / first inter-carrier difference information that is difference information with respect to the setting information of the first component carrier after the handover based on the setting information of the first component carrier before the handover, A wireless communication apparatus configured to set the first component carrier after the handover with reference to setting information of a first component carrier in use and the first / first inter-carrier difference information. The wireless communication apparatus according to claim 12, wherein
The wireless communication apparatus according to claim 1, wherein the first component carrier setting information which is a reference for the second / first carrier difference information is the first component carrier setting information after the handover. The wireless communication device according to claim 12 or 13,
The component carrier setting unit
According to predetermined information included in the setting message transmitted from the radio communication base station according to claim 5, all component carriers included in a component carrier set in use in communication with the radio communication base station A wireless communication apparatus that deletes a setting. The wireless communication device according to any one of claims 11 to 14,
The wireless communication apparatus, wherein the first component carrier is a primary component carrier. A wireless communication system in which a wireless communication device can communicate with the wireless communication base station by simultaneously using each component carrier of a plurality of communication cells managed by the wireless communication base station,
The wireless communication base station is
A first receiver for receiving information transmitted from the wireless communication device;
The radio using the component carrier set that processes the information received by the first receiver and includes a first component carrier used as a reference carrier and at least one second component carrier used simultaneously with the first component carrier. The component carrier that determines the component carrier set to be used when it is determined that communication with the communication device is performed or when it is determined that the carrier configuration of the component carrier set is changed during communication with the wireless communication device using the component carrier set A decision unit;
The second / first inter-carrier difference information, which is difference information with respect to the setting information of the second component carrier, based on the setting information of the first component carrier included in the used component carrier set determined by the component carrier determining unit. A difference information generation unit to generate;
A setting message generator for generating a setting message including the second / first carrier difference information;
A transmission unit for transmitting the setting message to the wireless communication device,
The wireless communication device
A second receiver for receiving the setting message transmitted from the radio communication base station;
A component carrier setting unit configured to set at least one component carrier based on component carrier setting information included in the setting message;
The component carrier setting unit
When the second / first carrier difference information is included in the setting message, the second component carrier is set with reference to the first component carrier setting information and the second / first carrier difference information. A wireless communication system.

Images