KR20130026371A - Method for processing signal of extension carrier and mobile telecommunication system for the same - Google Patents

Abstract

PURPOSE: A signal processing method of an extension carrier between heterogeneous networks and a mobile communication system thereof are provided to reduce interference for a PDCCH(Physical Downlink Control CHannel). CONSTITUTION: A management server(70) manages configuration information of subminiature base stations(11-15,21-23,31-33) and macro base stations(10,20,30). The management server performs functions of an SON(Self Organizing and optimizing Network) server(50) and an MME(Mobility Management Entity)(60). The SON server includes an arbitrary server which performs installation and optimization of the subminiature base stations and the macro base stations. The SON server includes the arbitrary server which provides a basic parameter or data necessary for each base station. The MME manages mobility of a terminal(40). The SON server and the MME manage one or more macro base stations and one or more subminiature base stations. [Reference numerals] (50) SON server; (70) Management server(O&M); (AA) IP network; (BB) Inter-RAT(WCDMA, CDMA, GSM, etc.)

Description

Signal processing method of EC in heterogeneous manganese and mobile communication system for it {METHOD FOR PROCESSING SIGNAL OF EXTENSION CARRIER AND MOBILE TELECOMMUNICATION SYSTEM FOR THE SAME}

The present invention relates to a mobile communication system, and more particularly, to a signal processing method of an extension carrier (EC) in a HetNet (Heterogeneous Network) environment.

"This study was carried out as a result of the study of the original technology development project of the next generation communication network of the Korea Communications Commission" (KCA-2011-10913-04002)

Recently, the use of mobile phones and mobile data in homes is continuously increasing, and according to this trend, a method of providing a mobile communication service by installing a micro base station indoors to access a mobile communication core network through an indoor broadband network is proposed. It is becoming. In particular, in the next generation network system, a method of deploying multiple small cells (femtocells) has been proposed as an alternative to meet the demand for high data rates and to provide a variety of services. The micro base station that manages such a small cell is called a pico base station, indoor base station or femto base station, and 3GPP as Home-eNB and HeNB. By reducing the size of the cell to service the indoor environment, the efficiency of the next-generation network system using the high frequency band can be improved, and the use of multiple small cells can increase the frequency reuse frequency. Do. In addition, the present invention can improve the channel deterioration problem due to the attenuation of radio waves, which is caused when a single base station covers the entire cell area, and the inability to service shadow users. Has this advantage.

As such, the mobile communication system has a cell structure for efficient system configuration. A cell is an area that is divided into small areas in order to efficiently use frequencies. A multiple access system typically includes multiple cells. In general, the base station is installed in the cell to relay the terminal.

HetNet is a method of using a plurality of base stations overlapping areas of different sizes instead of a single cell processing method. For example, small cells such as pico, femto cells, and relays are additionally installed in the macro cell area, thereby distributing networks in high-traffic areas from macro cells. By doing so, you can increase capacity and speed up data processing, increasing the overall efficiency of your network.

Extension Carrier (EC) to be introduced in 3GPP Release (hereinafter referred to as 'REL') 11 includes Physical Downlink Control Channel (PDCCH), Physical Hybrid ARQ Indicator Channel (PHICH), Physical Control Format Indicator Channel (PCFICH), and Common Reference Signal (CRS). (BCS) because it does not transmit control signals and channels, such as PSS (Primary Synchronization Signal), Secondary Synchronization Signal (SSS), Physical Broadcast Channe (PBCH), System Information Block (SIB), Paging, etc. In the Serving Component Carrier Set (SCCC) that includes the Backward Compatible Component Carrier (SCC), it must exist and exist in the BCCC, and mobility is based on the measurement of the BCCC. Since peak data rate and cell spectral efficiency are minimized while minimizing overhead, initial cell camping of UE (User Equipment) is not available with associated BCCC during carrier aggregation. It is used as a data only carrier.

In the HetNet environment, control signals and channels will be sensitive to interference, so ECs that do not transmit control signals and channels provide the advantage of not having to manage interference for these control signals and channels. In comparison with CA (Carrier Aggregation) through the same bandwidth of NC (Normal Carrier) on the UE side, it does not allow RRM (Radio Resource Management) measurement, and in terms of frequency due to efficient UE power consumption and the use of Cross Carrier Scheduling (CCS) EICIC (Enhanced Inter-Cell Interference Control) is also provided.

The NC and BCCC specified in the present invention mean frequencies already defined for EUTRA in 3GPP REL 8 and are regarded as carriers of the same concept.

1 is a diagram showing an example of the use of EC in the HetNet environment. For example, in the case of operating HetNet with two carriers, CC2, which is retained in BCCC (CC1), is set to EC while CC (Component Carrier) 1 is used as a BCCC in a macro cell, and a small cell ( In small cell), the CC2 corresponding to the EC of the macro cell is set to BCCC and the CC1 remaining in the BCCC (CC2) is set to EC to operate, thereby providing CA while minimizing interference of the PDCCH.

Specifically, when one operator operates a macro cell with two carriers and simultaneously operates a small cell in the macro cell, the macro cell minimizes PDCCH interference to the small cell by setting CC1 to BCCC in the macro cell. In order to provide CA for increased bandwidth for UE), another CC2 composed of one of REL 8 bandwidth sets is operated as EC while additionally cell specific to the corresponding BCCC, whereas in small cell, CC2 corresponding to EC of macrocell By using the CCCC and CC1, which additionally persists in the BCCC, is used as the EC, minimizing interference to a control signal and providing a CA at the same time in a HetNet environment. In other words, if the operator operates HetNet using two carriers of 10M bandwidth, if both carriers are used as NCs and provide CA, the effect of 20M bandwidth may be due to mutual interference on control signals such as PDCCH and CRS. It is difficult to obtain and if the timing of transmission is avoided to avoid this, it is inevitable to apply differential reception timing for data to be received through two carriers at the same time, which would be ineffective in terms of power consumption of the UE. .

Therefore, considering CA and eICIC in this HetNet environment, rather than using all carriers as NCs, if one carrier is defined as EC mutually exclusively under each heterogeneous network and used only for PDSCH transmission, each in each heterogeneous network Simultaneous transmission effect of 20M bandwidth will minimize the interference to the control signal will result in improved cell performance.

In case of CA using NC defined in REL 10, UE may have SCCS composed of up to 5 CCs, and multiple serving cells configured with one PCell (Primary Cell) and multiple SCells (Secondary Cell) A service can be provided from a serving cell, and a plurality of SCells are divided into PDCCH scheduling (Sell) and non PDCCH (Scheduled SCell) for UE power consumption and PDCCH load distribution. Therefore, the EC will have similar characteristics to the non PDCCH SCell in REL 10.

In case of applying the related schemes defined for REL 10 CA to REL 11 in the HetNet environment as described above for EC to be introduced in REL 11, the definition, characteristics and signaling scheme of EC to be considered in layer 2 or higher (MAC, RRC) Consideration is needed.

 R1-101712, "Reply LS on additional carrier types for LTE-A"  R1-100813, "WF of carrier types"

An object of the present invention is to provide an EC signal processing method and a mobile communication system therefor to be introduced in 3GPP REL 11 on an access link in order to increase frequency use efficiency and reduce interference to PDCCH in a HetNet environment.

According to an aspect of the present invention, there is disclosed a signal processing method of an EC to be introduced in 3GPP REL 11 on an access link for increasing frequency usage efficiency and reducing interference to PDCCH in a HetNet environment, and a mobile communication system therefor. According to the present invention, one carrier is defined as an EC (Extension Carrier) which mutually exclusively defines an Extension Carrier (EC) used for increasing frequency utilization efficiency and reducing interference to a physical downlink control channel (PDCCH) under each heterogeneous network. However, BCCC (Backward Compatible Component Carrier) is assigned to the EC. Here, the EC has one-to-one association with one BCCC in a SCCC (Serving Component Carrier Set) and transmits a channel state information reference signal (CSI-RS) for measuring channel quality information (CQI).

According to the present invention, the introduction of EC in the HetNet environment has the advantage of increasing the wave usage efficiency and reducing interference to the PDCCH.

1 illustrates an example of the use of EC in a HetNet environment.
2 illustrates a configuration of an exemplary mobile communication network in which the present invention may be implemented.
Figure 3 shows a problem in REL 11 CA using NBCCC as EC.
4 shows a problem when multiple BCCCs have an association with EC.
FIG. 5 is a comparison of SIB specification and modification schemes for EC. FIG.
6 shows UL linking for EC under HeNet.
7 illustrates a state management scheme for the EC.
8 is a diagram illustrating a case where a separate deactivation timer for EC is applied.
9 shows an example of modification to REL 10 RRC RRCConnectionReconfiguration.
10 shows an example of carrier setup for CA via REL 11 EC in a HetNet environment.
FIG. 11 shows an example of CA application to a macro UE using EC for REL 11; FIG.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. In the following description, well-known functions or constructions will not be described in detail if they obscure the subject matter of the present invention.

2 is a diagram illustrating a configuration of an exemplary mobile communication network in which the present invention can be implemented.

In one embodiment, the mobile communication network includes, for example, Global System for Mobile communication (GSM), 2G wireless communication network such as CDMA, LTE network, wireless Internet such as WiFi, Wireless Broadband Internet (WiBro) and World Interoperability for Microwave Access. Mobile communication networks (e.g., 3G mobile networks such as WCDMA or CDMA2000, 3.5G mobile networks such as High Speed Downlink Packet Access (HSDPA) or High Speed Uplink Packet Access (HSUPA)) 4G mobile network currently in service, etc.) and macro base station (macro eNB), micro base station (Pico eNB, HeNB (Home-eNB)) and any other mobile communication network including the UE (UE) as a component However, the present invention is not limited thereto. Hereinafter, an evolved universal terrestrial radio access network (e-UTRAN), which is a wireless access network of LTE, will be described.

As shown in FIG. 2, the mobile communication network may be composed of one or more network cells, and includes a HetNet environment in which different types of network cells may be mixed in the mobile communication network. The mobile communication network is a small base station (Pico eNB, HeNB, relay, etc.) managing small network cells (eg, 'small cells' such as picocells and femtocells) (11 ~ 15,21 ~ 23,31 ~). 33), macro eNBs 10, 20, 30, UEs 40, and self organizing & optimizing networks (SONs) that manage a wide range of cells (eg, 'macro cells'). The server 50 may include a Mobility Management Entity (MME) 60, a Serving Gateway (S-GW) 80, and a PDN Gateway (P-GW) 90. The number of components shown in FIG. 2 is exemplary, and the number of components of the wireless communication network to which the present invention can be implemented is not limited to the number shown in the drawings.

The macro base stations 10, 20, and 30 may be used in, for example, LTE, WiFi, WiBro, WiMax, WCDMA, CDMA, UMTS, GSM networks, for example, cells having a radius of about 1 km. It may include a feature of the macro cell base station for managing, but is not limited thereto.

The small base stations 11-15, 21-23, 31-33 can be used, for example, in LTE networks, WiFi networks, WiBro networks, WiMax networks, WCDMA networks, CDMA networks, UMTS networks, GSM networks, and the like. It may include, but is not limited to, features of a pico base station, an indoor base station or a femto base station, a relay that manages a cell having a radius of about m to several tens of meters.

The micro base stations 11 to 15, 21 to 23, 31 to 33 and the macro base stations 10, 20 and 30 may each independently have connectivity of the core network.

The UE 40 is used in 2G wireless communication networks such as GSM networks, CDMA networks, wireless Internet networks such as LTE networks, WiFi networks, mobile Internet networks such as WiBro networks and WiMax networks, or mobile communication networks supporting packet transmission. It may include features of the mobile terminal, but is not limited thereto.

The management server (O & M server) 70, which is a network management device of the micro base station, is responsible for the configuration information and management of the micro base stations 11 to 15, 21 to 23, 31 to 33 and the macro base stations 10, 20 and 30. . The management server 70 may perform both functions of the SON server 50 and the MME 60. The SON server 50 may include any server that functions to perform macro / miniature base station installation and optimization and to provide basic parameters or data required for each base station. The MME 60 may include any entity used to manage mobility of the terminal 40 and the like. In addition, each MME (61, 62) performs the function of a base station controller (BSC), resource allocation, call control, handover control, voice and packet processing for the base station (pico eNB, HeNB, macro eNB, etc.) connected to it And the like.

In one embodiment, one management server 70 may perform the functions of both the SON server 50 and the MME 60, and the SON server 50 and the MME 60 may be one or more macro base stations 10. 20, 30 and one or more micro base stations 11 to 15, 21 to 23, 31 to 33 may be managed.

In the mobile communication network, it is assumed that a macro cell, a pico cell, and a femto cell are mixed, but the network cell may be configured only by the macro cell, the pico cell, and the macro cell-femto cell.

In operation, access to the macro base stations 10, 20, and 30 is normally allowed to all terminals, but access to the micro base stations 11 to 15, 21 to 23, 31 to 33 is restricted to specific terminals (subscribers). There is an operation function that can be done. This is called a connection mode or an operation mode, and the connection modes of the small base stations 11 to 15, 21 to 23, 31 to 33 are classified according to which terminal provides a service. That is, it is divided into a closed connection mode, an open connection mode, and a hybrid connection mode. Closed access mode (closed access mode or CSG closed mode) allows access only to specific subscribers, and open access mode (open access mode or CSG open mode) is a mode that can be accessed by any subscriber without access permission conditions. Hybrid) is a compromise.

Specifically, the micro base stations 11 to 15, 21 to 23, 31 to 33 may broadcast system information block type 1 (SIB 1), which is system information, in a femtocell area managed by the base station (11 to 15, 21 to 23, 31 to 33). A Closed Subscriber Group indicator is included to indicate whether access to the femtocell is restricted. SIB 1 is a message that a base station (HeNB, macro eNB) broadcasts information about its cell to all the terminals 40. The cell global identity (CGI) (the only cell delimiter in the network) and the CSG indication (miniature base station) It is a factor indicating that the (), CSG ID (ID for the CSG) and the like.

When the mobile communication network is assumed to be an LTE network, the LTE network is interworked with an inter-RAT network (WiFi network, WiBro network, WiMax network, WCDMA network, CDMA network, UMTS network, GSM network, etc.). (LTE network, WiFi network, WiMax network, WCDMA network, CDMA network, UMTS network, GSM network, etc.) when one of the inter-RAT networks (e.g., WiBro network) is the mobile communication network. (WiFi network, WiMax network, WCDMA network, CDMA network, UMTS network, GSM network, etc.) are shown apart from each other in the drawing, (Overlay).

When the micro base stations 11 to 15, 21 to 23, 31 to 33 and / or macro base stations 10, 20 and 30 are collectively named as 'base station devices', E-UTRAN composed of base station devices of LTE It has an IP-based flat structure and processes data traffic between the terminal 40 and the core network. The MME 60 is responsible for controlling the signals between them. The MME 60 is responsible for signal control between the base station apparatus and the S-GW (Serving Gateway) 80, and determines where to route the incoming data from the terminal 40. S-GW (80) is responsible for the anchor (anchoring) function for the movement of the terminal between the base station and the base station, the 3GPP network and the E-UTRAN, P-GW (PDN (Packet Data Network) Gateway (90) Connect to IP network through The MME 60 / S-GW 80, which is the core network equipment, manages a plurality of base station apparatuses, and each base station apparatus includes a plurality of cells. The C-plane / U-plane is controlled between the base station apparatus and the MME 60 / S-GW 80 through the S1 interface, and uses the X2 interface for the handover and the SON function between the base station apparatuses.

The setup of the network interface is made by setting the S1 interface connecting with the MME 60 in the center of the system and the X2 interface, which is a network line for direct communication with the base station apparatus of other cells currently present in the system. The S1 interface exchanges signals with the MME 60 to support movement of the UE 40.

Management) Send and receive information. In addition, the X2 interface exchanges signals for fast handover, load indicator information, and information for self-optimization between base station devices.

When applying the related schemes defined for REL 10 CA to REL 11 in the HetNet environment where different types of network cells are mixed, the following points should be considered.

As a first consideration, Non-backward Compatible Component Carrier (NBCCC) means a carrier of a frequency band that can be newly defined in REL 11 that is not included in the frequency band currently defined in REL 10. Therefore, 3GPP currently defines that at least one BCCC should exist in SCCS including EC. However, the EC itself is not yet clearly defined in 3GPP, so a clear definition is required. In other words, the problem that may arise when using NBCCC for EC should be examined.

The second consideration is whether the EC and BCCC support multiple associations. That is, since the EC is cell specific, at least one BCCC must exist in the SCCS including the EC. Consider the advantages and disadvantages of an EC having multiple associations with one or more BCCCs.

As a third consideration, the signaling scheme for the association of the EC with the BCCC for the UE and the signaling elements for the EC itself should be determined.

Fourth consideration is UL resource linking to the EC. Since SCell is UE-specific in REL 10 CA using NC, a cell existing as a specific carrier can be used as a cell for a different purpose for each UE, so that the UL resource linked to the DL resource of the cell can also be set differently. Differential allocation of DL and UL resources for is made available. Therefore, when the EC is expected to be introduced in REL 11, it should be examined whether the UL linking scheme in REL 10 CA can be reused for the EC as it is.

As a fifth consideration, we should consider whether the SCell activation / deactivation scheme introduced in the REL 10 CA to reduce UE power consumption is applicable to the EC as it is.

Sixth consideration, REL 10 CA provides appropriate data scheduling based on QoS measurement for CRS and Channel State Information Reference Signals (CSI-RS) for SCell for proper data scheduling for SCell. do. However, since the CA through the EC does not transmit the CRS on the EC, proper data scheduling on the EC is difficult and a method for this should be considered.

Hereinafter, a solution to the above considerations will be described.

Looking at the first consideration in detail as follows.

As shown in FIG. 3, among the two carriers, FA1 is BCCC and FA2 is NBCCC. When an operator assigned an EC uses a CA, the EC supports the EC if the EC is set to FA2 in a macro cell. Although the CA can be applied to the REL 11 UE in the macro cell using CCS, the REL 10 UE cannot apply the CA because it cannot recognize the FA2. In addition, in order to minimize interference of a control signal such as a PDCCH in a HetNet environment, the corresponding FA2 should be applied as a BCCC to all UEs in a small cell, and FA1 should be applied as an EC. Accordingly, as shown in FIG. 3, since the FA2 to which the PDCCH for FA1 (set to EC using CCS) is signaled in the small cell is NBCCC, legacy UEs in the small cell can camp on FA2. Also, the BCCC FA1 will not receive any service because there are no control signals such as CRS and PCFICH. In addition, according to the definition of EC, at least one BCCC may not exist in the SCCS to which FA1, which is an EC, belongs in the small cell, thus colliding with the definition of EC of REL 10.

Thus, under heterogeneous networks (for example, FA1 assigns BCCC and FA2 assigns NBCCC), one carrier is mutually exclusively defined as EC under each heterogeneous network, and EC must be BCCC, and EC in REL 11 is defined as EC. There is no need to consider new frequency bands for this, so a new definition for the frequency bands to be included in the definition of EC in the RRC will not be needed.

Looking at the second consideration in detail as follows.

According to "R1-100813 (WF of carrier types)", at least one BCCC must be present in the SCCS to which the EC belongs. That is, there can be multiple BCCCs in one SCCS, implying that multiple BCCCs can be related to one ECCS.

For example, when configuring the SCCS for one UE with three CCs as shown in FIG. 4, one EC1 may be multi-associated with two BCCCs in a macro UE, in which case the eNB assigns PDSCH to EC1. PDCCH load distribution is possible because PDCCH can be selected and allocated to any one of the two BCCCs, but the UE will be a waste in terms of power consumption since the two BCCCs must be monitored simultaneously according to a common DRX cycle. On the other hand, the corresponding SCCS in the small cell UE will be a shape in which one BCCC associates two EC 1,2, in which case each PDCCH for two ECs must be allocated to one BCCC, so that the BCCC is REL 11 PDCCH for PDSCHs of UE and PDCCH for legacy UE camped in FA2 may cause PDCCH bottleneck in corresponding BCCC.

As a result, there is no clear advantage in both heterogeneous networks for multi-association applications, and the complexity of signaling and management at higher layers is expected, so that each EC in the SCCS must be established in association with one BCCC. Must have a: 1 association.

Looking at the third consideration in detail as follows.

In order for the existence of the EC and the indication of the associated BCCC for the EC and the data transmission and reception on the EC, signal elements to be signaled to the UE must be determined, and overall signaling schemes for the ECs must be determined. The signal element will require a lot of information, including at least frequency band and bandwidth, but unlike the SCell NC with the reuse of information elements (IEs) predefined for SCell configuration at the R10 CA because the EC is not used as a PCell. It would be effective to add a xxx-r11 IE for a separate IE that is additionally required for SCell EC.

In addition, to indicate the association of BCCC and EC, as shown in FIG. 9, the associated BCCC, which is a scheduling cell for the EC, is specified through CrossCarrierSchedulingConfig-r10 defined in REL 10, and a corresponding extension is made through a new extensionCarrierIndicator-r11 IE when SCell is added. Specifies whether the SCell is EC or not.

Three signaling assumptions can be made as follows, and the EC information indication and the change of the EC information should be considered for the UE. First, the EC may consider a method of specifying the EC existence through broadcast transmission for its SIB (System Information Block), but it is not applicable because the EC does not transmit the PBCH. Secondly, a method of specifying the existence of the EC through broadcast transmission of the SIB of one BCCC related to the EC may be considered. Third, it may be considered that the EC transmits the EC SIB as a dedicated signal without broadcasting the SIB.

The EC signaling and information change scheme through the SIB of the associated BCCC of the EC, which is the second signaling scheme, may be divided into two cases when BCCC is used as a PCell and SCell as shown in (case1) of FIG. 5. According to the REL 10 CA definition, when operating as a PCell, an RRC reconfiguration procedure is required to change the CCS associated with the EC after two modification periods for paging reception and modified SIB information reception, while BCCC transfers to the SCell. In operation, the CCS associated with the EC can be changed at the same time as the SIB is recognized by resetting the CCS and receiving the changed SIB information of the SCell in the RRC reconfiguration procedure. Therefore, the above method requires a different procedure according to the cell type (cell type) used of the BCCC, and in particular, in the case of the PCell, to determine the starting point of the procedure for resetting the RRC after receiving the changed SIB information from the eNB with the change delay. It may be difficult, and there is a disadvantage that an additional xxx-r11 SIB IE must be added to the REL-8 SIB to specify information about the EC.

In addition, the method of specifying and changing the EC through the RRC dedicated message, which is the third signaling method, should be transmitted through the dedicated message to all REL 11 UEs using the EC when changing the information of the EC. However, in the scheme using the RRC-only message, the eNB can clearly recognize the reset completion reception of all UEs by receiving the response message for the corresponding message, and at the same time, the CCS reset can be performed simultaneously with the changed SIB information indication. It can be processed more quickly than the method, and since the EC can not be used as a PCell, it can be performed in the same procedure regardless of the cell type of the associated BCCC, and also REL10 RRC predefined for REL 10 CA. The radioResourceConfigCommonSCell-r10 IE within the reconfiguration can reuse relevant information for EC SIB specification, minimizing changes in specification. Accordingly, the EC proposes a (case2) scheme for signaling the presence of the EC to the UE by signaling the SCell separate from the associated BCCC through an RRC-only message. ECs that do not allow NC and cell type changes are treated as independent SCells that have an association with the associated BCCC.

Looking at the fourth consideration in detail as follows.

Since the EC will always play the role of No PDCCH SCell with the associated BCCC as the PCell or PDCCH SCell, the eNB can use the dedicated message to save the UE's SIB2 linked UL resources in a dedicated message to prevent the UE's power consumption, like the NC SCell of REL 10 CA. It is effective to direct. In addition, as shown in FIG. 6, when the operators assigned two BCCC FA1 and FA2 apply the CA in the HetNet using EC, if the EC is set to FA2 in the macro cell, the small cell FA2 is used as a PCell, so that small cell UEs will be aware of the UL resources linked to SIB2 through SIB acquisition, and the UL resources will not be seen through SIB acquisition to macro cell UEs. All UEs using EC should be signaled with a dedicated message.

Therefore, the method of signaling UL resources for the NC SCell may be reused to signal UL resources of the EC in the RRC Connection Reconfiguration message previously defined in the REL10 CA (in one embodiment, the UL linking for the EC may be used). REL 10 CA in the same manner as the UL linking for SCell), as shown in Figure 6 RRC to enable the differential resource configuration between different uplink and downlink, such as REL 10 CA for UEs in the macro cell and small cell The dedicated message may indicate UL resource linking that is the same as or different from the SIB2 linked UL resource. This means that no change is required for UL resource linking of REL 10 NC for UL resource linking of REL 11 EC.

Specifically, the fifth consideration is as follows.

For SCell management in REL 10 CA, eNB scheduler is usually added to SCell after good RRM for NC, but the initial MAC state of the SCell is deactivation to prevent power consumption of the UE. If additional bandwidth is required due to an increase in the data volume, the MAC state of the corresponding SCell is changed to an active state through a MAC Control Element (MAC) indicating activation. Channel Quality Indication (CQI) measurements are performed to enable proper data scheduling on the SCell. In addition, the deactivation of the SCell via the MAC CE indicating activation when bad CQI or data volume reduction for the activated SCell, and in the deactivated state, the CQI measurement is no longer performed, thereby preventing UE power consumption.

In the REL 10 CA, the SCell deactivation timer is for preventing a synchronization problem in the deactivation state with the UE due to an explicit deactivation not received by the eNB. The UE starts the timer after receiving the activation for each SCell, and upon receiving new data or grant, the timer is restarted to maintain the activation while continuing with the channel quality indication (CQI) and SRS ( Sounding Reference Signal). If the eNB performs an explicit deactivation procedure due to bad CQI, the eNB will not assign any data and grant to the SCell, which causes the timer to expire and cause the eNB to expire. In the case of explicit deactivation, i.e., transmission or non-receipt of MAC CE indicating SCell deactivation, the UE automatically transitions the corresponding SCell to the inactive state to match the MAC state of the corresponding SCell. This is called an "implicit deactivation procedure."

In REL 11, EC can be intra / intercontinental or interband with the associated BCCC and does not transmit CRS, so BCCC addition / deletion by RRM measurement result for the associated BCCC The association EC must also be added / deleted at the same time, and activation should only activate BCCC or BCCC & EC, depending on the extent of data volume growth. In addition, depending on the degree of data volume reduction, only EC or BCCC & EC should be deactivated. In other words, activation / deactivation of the EC should be possible separately from the associated BCCC. However, when bad CQI for BCCC can no longer transmit the PDCCH for the EC, the EC must also be activated at the same time. 7 is a state management scheme for the EC in REL 11.

The following is an improvement in unnecessary CQI measurement and UE power consumption for SRS transmission in the case of an activated EC, and in the case of a continuous EC, the result will be almost similar to that of the associated BCCC even if RRM is not performed. If the associated BCCC is added, the EC will also not be a problem for activation following addition. In other words, when the reference signal received power (RSRP) or reference signal received quality (RSRQ) for the CRS of the continuous BCCC is above a certain reference value, the EC located in the continuous frequency is also almost similar, and the EC deactivation by the CQI measurement result after the EC activation is almost similar. The condition will rarely occur. On the other hand, in the case of non-continuous EC, even if RSRP and RSRQ of the associated BCCC are above the addition threshold, explicit deactivation may be driven by eNB due to Bad CQI when measuring CQI for EC. Likely, but as the volume of data continues to increase, the scheduler tries to keep both the SCell and the EC active. Therefore, such continuous maintenance of the non-contiguous EC will result in unnecessary power consumption due to unnecessary CQI measurement and SRS, and a method for reducing such power consumption is required.

As a solution to this problem, there is a method of performing deactivation for EC faster than RRM-based associated BCCC and maintaining a longer deactivation state. To this end, the fast deactivation can be achieved by setting a short CQI reporting period, which can be supported by the SCell-specific CQI reporting settings defined in REL 10. The following describes how to use the new SCell deactivation timer in REL11 CA to maintain a longer deactivation state through FIG. 8.

Basically, performing fast deactivation eventually means frequent explicit deactivation, which will require more frequent implicit deactivation procedures. As shown in FIG. 8, when the deactivation timer for the EC is applied with the same value as the NC based on the RRM result, the eNB does not allocate any data to the EC of the bad CQI during the deactivation timer. It consumes power for unnecessary CQI and SRS for the same time. In other words, by applying a deactivation timer of different length from the NC, it is possible to reduce unnecessary CQI measurement time for SCell EC of low RSRP and RSRQ, which will help UE power consumption. Therefore, it defines a separate deactivation timer for the EC and signals the IE by the eNB according to the continuity with the carrier development environment and the associated BCCC, and the UE applies the timer equally to all ECs in the SCCS and manages for each EC. do. 8 is a case where CC2, which is an NC SCell, is associated with a non-contiguous EC CC3, and the upper CC3 (EC) applies the same values for the CQI reporting cycle for the NC SCell (associated BCCC), the SCell deactivation timer, and the lower CC3 (EC). ) Is a case where a separate CQI reporting period and an SCell deactivation timer for the EC are applied. In FIG. 8, the EC is not based on RRM and is further discontinuous. Therefore, even if BCCC, which is CC2, is capable of continuous data scheduling with good CQI, the EC is an example of repeated activation and deactivation due to bad CQI. Assuming the two errors for the MAC deactivation CE during the time, the EC compares the time that the EC maintains the MAC deactivation without performing the CQI measurement and the SRS transmission. As shown in FIG. 8, by applying a new SCell deactivation timer less than the timer for NC, it can be maintained in the MAC deactivation state which does not consume the UE power for a longer time in a unit time.

In addition, there is no separate deactivation command for the UL when deactivating the SCell in REL 10, and the SIB2 linked UL signaled through SIB2 is also deactivated when the DL is deactivated. However, by using only a dedicated signal for UL linking to the EC, it is possible to link UL resources that are not identical to the SIB2 linked UL signaled via SIB2 as in REL 10, in which case there is no SIB2 linked UL resource. It will consist of a DL Cell using EC. Therefore, the MAC CE deactivation command for the EC is accompanied with UL deactivation for the SIB2 linked UL for the EC, like the NC SCell.

The sixth consideration is described in detail as follows.

Since there is no CRS in the EC, CRS based RRM and CQI measurement is impossible, so SCell addition / deletion and SCell activation / deactivation will always be dependent on the RRM and CQI for the associated BCCC. It should be based on the results of the CQI measurement. However, in the case of an associated BCCC and EC of discontinuous bands, this scheduling will lead to inefficient data scheduling. The UE supporting the EC is a REL 11 UE and supports the CSI-RS introduced in the REL 10. Therefore, it is necessary to be able to signal the CSI-RS to the EC for individual CQI measurement for the EC, and to do so by reusing the CSI-RS-Config-r10 IE for the SCell in the RRC RRCConnectionReconfiguration message defined for the REL 10 CA. Proper data scheduling for the EC is possible if the same or different configuration as the BCCC is possible. Therefore, unlike other control signals, the EC should transmit at least the CSI-RS for CQI measurement.

Hereinafter, a description will be given of a specific embodiment of using a dedicated message for specifying an EC together with an operation description in a CA using the EC to which the above proposals are applied.

The REL 10 RRC Reconfiguration message shown in FIG. 9 partially specifies IEs that are highly related to CA when using the EC. Based on this, the change in the REL 11 dedicated message considering the EC is indicated in yellow. Since the PHICH for the SCell in REL 10 allows type change between the SCell and the PCell, the SCell PHICH-Config IE is signaled to the UE as a mandatory. However, since EC is cell specific, cell type change is not allowed. Therefore, when used as SCell, the corresponding IE should not be included. However, since the UE has already recognized that the carrier is the EC through the extensionCarrierIndicator-r11, the PHICH configuration may be ignored by the UE. In addition, since EC needs to operate as BCCC, ARFCN-ValueEUTRA IE defined in REL 10 is reused for frequency information of EC acting as SCell. Finally add a new IE, sCellDeactivationTimer1-r11, to signal different SCell deactivation timer application of less length than that of NC to EC.

FIG. 10 illustrates frequency configuration in a HetNet environment, and a signaling scheme using the modified RRConnectionReconfiguration defined in FIG. 9 when the CA through the EC for the REL 11 macro UE is configured in FIG. 11 when two BCCC & EC sets are configured in each network. do.

In FIG. 11, the macro UE has cell camping on FA1 and established an RRC connection through FA1. Accordingly, the PCell for the corresponding UE is determined to be FA1, and as in step 2, the eNB acquires the access release version and CA capability of the UE by the UE capability query procedure. In addition, in step 3, if the UE is REL 11 and CA is possible, the eNB sets FA2 associated with FA1 with the SCell at the same time as the PCell through the RRC Reconfiguration message and sets the addition to the SCell, and drives the measurement for FA3. In this case, the cell index of the PCell is “0”, and the EC1 is “1”, which sets the PCell as the scheduling cell for the PDCCH for the EC1 and indicates that the FA2 is the EC through the extensionCarrierIndicator-r11 to the BCCC and the associated EC1. Instructs the UE to link to the UE. In addition, EC1 is activated by the data volume in Step 4, and the SCell deactivation timer for EC is driven on the UE side. However, in step 5, the corresponding EC1 is deactivated by the eNB for bad CQI. In addition, in step 6, the RRM measurement result for FA3 determines the addition of FA3 as a new SCell, but in step 5, since there is an EC2 associated with FA3, the corresponding FA3 and FA4 are simultaneously added as SCell, and as a scheduling cell for PDCCH for EC2. It establishes the association BCCC2 (FA3) and instructs the UE to link the BCCC2 and the association EC2 by indicating that FA4 is an EC through extensionCarrierIndicator-r11. In addition, in step 9, all SCells are activated by the rapid increase in data volume. On the UE side, two SCell deactivation timers are driven for NC and EC SCells. REL 11 UE is the corresponding SCell and ECBC2 is associated with the scheduling cell. Note that it is the carrier specified. According to the CQI information for each carrier, the appropriate grant is transmitted to EC1 and 2 through PCell and BCCC2. Here, activation of the EC alone is not possible without activation of the associated BCCC.

Although the method has been described through specific embodiments, the method may also be embodied as computer readable code on a computer readable recording medium. A computer-readable recording medium includes all kinds of recording apparatuses in which data that can be read by a computer system is stored. Examples of the computer-readable recording medium include a ROM, a RAM, a CD-ROM, a magnetic tape, a floppy disk, an optical data storage device, and the like, and may be implemented in the form of a carrier wave (for example, transmission over the Internet) . In addition, the computer-readable recording medium may be distributed over network-connected computer systems so that computer readable codes can be stored and executed in a distributed manner. In addition, functional programs, codes, and code segments for implementing the above embodiments can be easily deduced by programmers of the present invention.

Although the present invention has been described in connection with some embodiments thereof, it should be understood that various changes and modifications may be made therein without departing from the spirit and scope of the invention as understood by those skilled in the art. something to do. It is also contemplated that such variations and modifications are within the scope of the claims appended hereto.

10,20,30: Macro base station 11-15, 21-23, 31-33: Micro base station
40: terminal (UE) 50: SON server
60: MME 70: Management Server (O & M Server)
80: Serving Gateway (S-GW) 90: PDN Gateway (P-GW)

Claims (14)

As a signal processing method of EC (Extension Carrier) to heterogeneous manganese,
One carrier is defined as EC mutually exclusive under each heterogeneous network,
Allocating a backward compatible component carrier (BCCC) to the EC used for increasing frequency usage efficiency and reducing interference to a physical downlink control channel (PDCCH). The method of claim 1,
The EC has a one-to-one association with one BCCC in a SCCC (Serving Component Carrier Set). The method of claim 2,
The EC and the information change are specified through a new extensionCarrierIndicator-r11 IE in the SCellToAddMod-r10 IE of RRCReconfiguration, a dedicated message, the associated BCCC is specified through the CCS-r10 IE, and the SIB (System Information Block) related information about the EC. Transmitting through the dedicated message, the EC signal processing method. The method of claim 2,
The EC is treated as an independent SCell (Secondary Cell) having an association with an associated BCCC without allowing normal carrier (NC) and cell type (NC) of the same bandwidth to be changed. 5. The method of claim 4,
The uplink linking (UL linking) for the EC using the same as the UL linking for SCell in REL 10 Carrier Aggregation (CA). The method of claim 5,
The SCell addition / deletion of the EC is based on the RRM measurement result of the associated BCCC and is always performed together with the associated BCCC. The method according to claim 6,
After the SCell addition to the EC, the associated BCCC and the individual activation / deactivation state is applied,
SCell addition to the EC is possible if the associated BCCC is activated at the same time or BCCC is already activated,
When the BCCC is deactivated, the associated EC is deactivated simultaneously. The method of claim 2,
Define an inactivation timer of a different length from NC (Normal Carrier) for implicit deactivation of the EC, and apply the inactivation timer to all ECs in the SCCC equally and manage each EC. Treatment method. The method of claim 2,
The individual explicit deactivation of the EC is deactivated by the base station according to the channel quality information (CQI) measurement result of the CSI-RS of the EC. The method of claim 5,
EC deactivation for SIB2 linked UL upon MAC CE deactivation for the EC, the signal processing method of the EC. The method of claim 2,
And transmitting a channel state information reference signal (CSI-RS) to the EC for measuring individual channel quality information (CQI) for the EC. The method of claim 11,
The EC's signal processing method, which allows the same or different configuration as the associated BCCC by reusing the CSI-RS-Config-r10 IE for the SCell in the RRCConnectionRecondiguration message used for the REL 10 CA. As a heterogeneous mobile communication system,
One carrier is mutually exclusively defined as an extension carrier (EC), which is used to increase frequency usage efficiency and reduce interference to a physical downlink control channel (PDCCH) under each heterogeneous network.
Allocating a BCCC (Backward Compatible Component Carrier) to the EC. The method of claim 13,
The EC has one-to-one association with one BCCC in a Serving Component Carrier Set (SCCC) and transmits a channel state information reference signal (CSI-RS) for measuring channel quality information (CQI).

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