WO2013035941A1

WO2013035941A1 - Method for determining a pdsch start symbol of an ec between heterogeneous networks, and mobile communication system therefor

Info

Publication number: WO2013035941A1
Application number: PCT/KR2011/010060
Authority: WO
Inventors: 김상하; 박병성; 장일두; 이희봉
Original assignee: 엘지에릭슨 주식회사
Priority date: 2011-09-05
Filing date: 2011-12-23
Publication date: 2013-03-14

Abstract

In a HetNet environment having mixed heterogeneous networks, the physical downlink shared channel (PDSCH) start symbol of an extension carrier (EC) is determined by one network in consideration of the start symbol of a normal carrier (NC) backward-compatible component carrier (BCCC) on the same frequency in a different network.

Description

Method for Determining ECS PD Start Signal of Heterogeneous Manganese and Mobile Communication System

The present invention relates to a mobile communication system, and more particularly, to a method for determining a location of a physical downlink shared channel (PDSCH) start symbol of an extension carrier (EC) in a heterogeneous network (HetNet) environment.

"This study was conducted as a result of the next generation communication network source technology development project 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 a subdivision of a large area into smaller areas in order to use frequency efficiently. Multiple access systems generally include 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.

The Extension Carrier (EC), which is scheduled to be introduced in the 3GPP Release (hereinafter referred to as 'REL') 11, includes a Physical Downlink Control Channel (PDCCH), a Physical Hybrid ARQ Indicator Channel (PHICH), a Physical Control Format Indicator Channel (PCFICH), and a 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. Dat where initial cell camping of UE (User Equipment) is not available with associated BCCC during CA (Carrier Aggregation) because it increases peak data rate and cell spectrum efficiency while minimizing overhead used as a 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 provided.

1 is a diagram showing an example of the use of the EC in the HetNet environment. For example, in the case of operating HetNet with two carriers, CC (Component Carrier) 1 is set to BCCC in a macro cell, and CC2, which remains in CC 1, is set to EC and provided to a small cell. By setting CC2 corresponding to EC of macrocell as BCCC and setting CC1 which is additionally persisted to CC2 as EC, it provides CA while minimizing interference of PDCCH through CCS (Cross Carrier Scheduling) scheme for PDCCH. .

In the above HetNet environment, the start symbol of the EC in one network should be determined in consideration of the PDSCH start symbol of the BCCC of the same frequency in the other network. However, the current HetNet environment does not define the location of the PDSCH start symbol of the EC.

An object of the present invention is to provide a method for determining the position of the PDSCH start symbol of the EC in the HetNet environment and a mobile communication system therefor.

According to an aspect of the present invention, a method of determining a location for a PDSCH start symbol of an EC in a HetNet environment and a mobile communication system therefor are disclosed. According to the present invention, in a HetNet environment in which heterogeneous networks are mixed, when one network determines a physical downlink shared channel (PDSCH) start symbol of an EC (Extension Carrier), another network (NC) (Normal Carrier) BCCC (Backward Compatible) is the same frequency in another network. Determine in consideration of start symbol of Component Carrier). In this case, one network and the other network use the same or different network interfaces.

According to the present invention, by determining the position of the PDSCH start symbol of the EC in the HetNet environment in consideration of the PDSCH start symbol of the BCCC of another network, there is an advantage that can increase the frequency use efficiency and reduce the 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.

3 shows the relationship between PDSCH start symbols in a HetNet environment.

4 defines an interface between base stations in a HetNet environment.

Fig. 5 shows a table specifying a range of CFI values of PCFICH.

6 is a diagram illustrating a method of exchanging PDSCH start symbols using X2 and S1 interfaces in a HetNet environment according to an embodiment of the present invention.

7 is a diagram illustrating a REL 11 X2-AP Load Information message for exchanging an NC PDSCH start symbol according to an embodiment of the present invention.

8 illustrates a REL11 S1-AP eNB / MME X2-AP Transfer message for exchanging NC PDSCH start symbols according to an embodiment of the present invention.

9 is a view showing a comparison result for the scheme for NC PDSCH start symbol exchange.

10 and 11 illustrate REL 10 RRC Reconfiguration messages.

12 and 13 compare signal schemes for PDSCH start symbol indication of an EC according to an embodiment of the present invention.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings. However, in the following description, when there is a risk of unnecessarily obscuring the gist of the present invention, a detailed description of well-known functions and configurations will be omitted.

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. A mobile network is a very small base station (Pico eNB, HeNB, relay, etc.) (11-15, 21-23, 31-33) that manages a small number of network cells (eg, picocells, femtocells, etc.), and a wide range. Macro eNBs 10, 20, 30, UEs 40, Self Organizing & Optimizing Networks (SON) server 50, and MME (Mobility Management) to manage cells (eg, 'macro cells') It may include an entity (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.

If 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.). If one of the inter-RAT networks (for example, WiBro network) is the mobile communication network, it is also linked to other networks (LTE network, WiFI network, WiMax network, WCDMA network, CDMA network, UMTS network, GSM network, etc.). In the drawing, one network (for example, LTE network) and another network (WiFi network, WiBro network, WiMax network, WCDMA network, CDMA network, UMTS network, GSM network, etc.) are shown spaced apart from each other, but one network and the other network overlap. It is assumed that it is (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. Also, the X2 interface exchanges signals for fast handover, load indicator information, and information for self-optimization between base station devices.

In case of CA using EC in HetNet environment where different types of network cells are mixed, there is no PDCCH, which is a kind of control signal and channel, in the EC itself, so there is a Physical Control Format Indicator Channel (PCFICH) channel indicating the number of PDCCH symbols. Since the UE 40 receives the data using the EC, the UE cannot recognize the position of the PDSCH start symbol on the EC. On the other hand, since the PCFICH channel exists in the NC (Normal Carrier, backward compatible carrier) BCCC associated with the EC, that is, the carrier signaling the PDCCH for the EC, the UE 40 determines the position of the PDSCH start symbol of the NC BCCC by L1. It can be recognized by the signal.

In general, in case of an REL 10 CA that provides a wide bandwidth by allocating a plurality of component carriers (CCs) to the UE 40, since the plurality of CCs are all CCs managed by one eNB, the number of PDCCH symbols for each CC is determined. That is, the location of the PDSCH start symbol is semi-statistically determined based on an independent decision by the corresponding eNB scheduler, and thus a radio resource control (RRC) reconfiguration message, which is a dedicated message, to the UE 40 using the CC as a non-PDCCH serving cell. Is directed through. However, the PDSCH start symbol of a specific frequency CC used as an EC in a layer (macro cell or small cell) in a HetNet environment is affected by the number of PDCCH symbols using the same frequency as another NC. 3 is a diagram illustrating a relationship between PDSCH start symbols in a HetNet environment.

In FIG. 3, (case 1) is a case where the same PDSCH start symbol as the BCCC of its layer is applied to the EC without considering the PDSCH start symbol of the BCCC of another layer in the HetNet environment. In this case, if the start symbol of FA1, BCCC in the macro cell, is smaller than the start symbol of FA1, EC in the small cell, the PDSCH symbol of the small cell EC will be wasted, whereas the small cell If the start symbol of FA2, which is BCCC at, is larger than FA2, which is EC at macrocell, interference with the last symbol of PDCCH in BCCC FA2 will occur in the small cell.

Also, (Case 2 to 4) is a case where the PDSCH start symbol of the EC is determined while considering the PDSCH start symbol of BCCC of another layer in the HetNet environment. In addition, unlike (case 1), (case 2) will not cause serious errors such as PDCCH decoding error (decoding error). In addition, (case 4) is the case in which the same PDSCH start symbol is set for all CCs in a HetNet environment, in which case PDCCH resource waste may be caused.

Therefore, the PDSCH start symbol of the EC in one network should be determined in consideration of the PDSCH start symbol of the BCCC of the same frequency in the other network.

In order to circumvent this problem, we may consider applying X2 interchange between eNBs like the exchange of other ICIC-related variables, but it is not applicable in HetNet environment of macro-femto because it does not have X2 interface. Specifically, in REL 10 the X2 interface is between closed / hybrid access HeNBs with the same CSG ID or between them and an open acess HeNB without having access control to the MME 60 as shown in FIG. In other words, it is possible to use X2 interface in small picocell, but femtocell cannot use X2 interface, so the procedure in macro-pico environment cannot be applied to macro-femto environment. The solution is as follows.

Currently, REL 10 uses ABS for eICIC on the time side, and uses X2 interface for ABS (Almost Blank Sub-frame) pattern exchange between eNBs. The ABS pattern is determined by the operator through measurement of various environments such as UE activity, user average transmission speed, handover delay, antenna shape, and UE measurement performance in the cell. However, the PDSCH start symbol of the EC is influenced by the PDSCH start symbol of the NC of the same frequency of another network, and the NC PDSCH is dynamically determined by the eNB scheduler, so that it is not determined and set by an operator and is not determined by an operator. It is changed by UE activity per NC controlled by. Therefore, there is a slight difference between the ABS pattern and the PDSCH start symbol of the EC. However, although the ABS pattern and the PDSCH start symbol of the EC are semi-statistically changed by the eNB scheduler like the PDSCH start symbol of the NC SCell (Secondary Serving Cell) in REL 10 CA, the update cycle to the new value is ABS. The pattern information may take a shorter period than the PDSCH start symbol of the EC.

In the macro-femto environment corresponding to Scheme 2 of FIG. 9, the ABS pattern information of any femtocell is determined by the operator to the femto ABS pattern and directed to other femtocells and the corresponding macrocell through the management server 70. In addition, in the macro-pico environment, the ABS pattern information of the macrocell will be first transmitted to the macrocell through the management server 70 by the operator to determine the macro ABS pattern, and the macrocell is transmitted to the picocell using the X2 interface. You will be notified of your ABS pattern.

On the other hand, when the PDSCH start symbols of the EC are interchanged in the same manner as the ABS pattern, it can be divided into a method of exchange by the management server 70 through the operator's intervention and a method without the operator's intervention as follows.

First, the exchange method by the management server 70 through the intervention of the operator corresponds to Scheme 2 of FIG. 9, in which the operator has a specific carrier-specific UE activity in order for the operator to take over the role of all eNB schedulers configuring the HetNet. There is a problem that needs to be monitored to increase the burden on the operator in the network operation, PDSCH start symbol synchronization between the multiple eNBs in the PDSCH start symbol of the NC that can be changed in units of Transmission Time Interval (TTI) It won't be easy.

The method without the operator's intervention can be classified into two types as follows.

First, as shown in (case 4) of Figure 3, not only the operator, but also determined in accordance with the system parameters of the carrier without interworking with other eNB, Scheme 1 of Figure 9 corresponds to this. This method determines the PDSCH start symbol with the maximum number of PDCCH symbols + 1 according to the bandwidth and configuration information of the carrier based on a table specifying the range of the CFI value of the PCFICH shown in FIG. 5, and waste of resources may exist. However, no exchange between networks is required.

Secondly, as shown in case 3 of FIG. 3, the PDSCH start symbol of BCCC determined by each eNB scheduler is interchanged through the X2 interface. Scheme 3 of FIG. 8 corresponds to this. This approach can avoid wasted resources and PDCCH decoding errors.

6 shows a scheme for exchanging NC PDSCH start symbols using X2 and S1 interfaces under different types of HetNet environments. First of all, when looking at the variables related to the information in X2-AP, IEs for indicating the PDSCH start symbol of the NC and the frequency of the NC and the application time of the new start symbol will be required, which is a message for the ICIC of the REL10 X2-AP. It would be most effective to add the corresponding Information Elements (IE) to the Load Information message. As shown in Fig. 6, the Load Information message will indicate the position of PDSCH start symbol of its BCCC between macro-pico through X2-AP, which is commonly applied to

schemes

2 and 3 of FIG. On the other hand, since there is no X2 interface between macro-femto, two methods can be considered when exchanging corresponding information through S1 interface. One is a method of exchanging a new IE for related information in the S1-AP message defined in REL 10. The other is a method of defining a new REL 11 S1-AP message for eICIC between eNBs and transmitting the X2 load information message in a container form. 7 specifies a change to the REL 11 X2-AP Load Information message for NC PDSCH start symbol exchange.

In FIG. 7, the lower IEs 7a are new IEs for the corresponding procedure, and a new value "PDSCH Start information" is added to a predefined Invoke Indication. Looking at the meaning of the added value, the eNB that receives the message exchanges the PDSCH start information for the NC to the eNB that sent the message when the Invoke Indication value is "PDSCH Start information". For example, in case of CA, the frequency band of downlink NC corresponding to a maximum of 5 cells is indicated by EAFCN IE. On the receiving side, since the corresponding frequency is EC in its layer, the PDSCH of the EC is transmitted to the UE using EC through an RRC-only message. Indicating the start symbol, the BCCC NC recognizes the PDSCH start symbol directly through the PCFICH channel.

Specifically, as shown in FIG. 6, a change is required in S1-AP for exchanging corresponding information between macro-femto. In this case, it can be divided into "6a" and "6b".

In FIG. 6, "6a" indicates that there is no predefined message for exchanging eICIC in REL 10 S1-AP, so that new IEs for eNB / MME Configuration Transfer message related information defined for exchanging SON information are added. It is a way of exchanging information. This method requires a change in the detailed procedure of eNB / MME Configuration Transfer.

In addition, in FIG. 6, "6b" indicates a REL 11 X2-AP Load Information message (see FIG. 7) defined for information exchange between macro-pico (see REL11 S1-AP eNB / of FIG. 8). MME X2-AP Transfer message) is included in the form of a container and exchanged. This method does not require any change in the S1-AP procedure defined in REL 10, and can be used for exchanging ABS pattern information between macro-femto. Therefore, the present invention proposes "6b", and for this purpose, a new eNB / MME X2-AP Transfer message (REL 11 X2-AP Load Information message of FIG. 7), which is a REL 11 S1-AP message for NC PDSCH start symbol exchange, is newly proposed. It defines and specifies the detailed procedures for the procedure.

The REL 11 X2-AP Load Information message of FIG. 7 is included in the X2-AP container of the new S1-AP message (REL11 S1-AP eNB / MME X2-AP Transfer message) of FIG. 8 and transmitted by the MME 60. It is transparently delivered to the target eNB through the target eNB-ID set by. In response, the receiving eNB uses the information contained in the X2-AP Load Information message of the transmitting eNB, generates a X2-AP Load Information message indicating its NC PDSCH start symbol in response, and determines the source eNB determined by the transmitting eNB. -ID is determined as the target eNB-ID and transmitted to the MME 60. Then, the MME 60 transparently delivers the X2-AP container to the target eNB through the target eNB-ID set by the transmitting eNB. This exchanges information about the PDSCH start symbol between eNBs. In another embodiment, the REL11 S1-AP eNB / MME X2-AP Transfer message may be used for ABS pattern information exchange in eICIC between macro-femto in terms of time.

9 is a comparison chart for the three schemes. As shown in FIG. 9, in the case of scheme 2, the UE activity monitoring is required for each operator's career, and in the case of scheme 3, the operator's intervention is not required, but like

scheme

2, 100% cannot be supported for resource wasting and PDCCH decoding error. The reason is that it is difficult to determine the dynamic PDSCH start symbol by UE activity for 256ms due to the same activation synchronization between heterogeneous networks and delay period of SFms maximum length of 256ms in X2-AP, S1-AP, O & M message exchange. In addition, each network applies a dedicated signal to the UE 40 using the EC in each network to apply the position of the new PDSCH start symbol of the EC to the next SFN 0 according to the PDSCH start symbol received from the other network. However, since it is not possible to guarantee that all UEs 40 always activate the new value at the same time in SFN 0, they may not be able to 100% avoid resource waste and PDCCH decoding error per individual UE.

The EC has already included IE such as CrossCarrierSchedulingConfig-r10 IE in the message in consideration of the introduction of EC when defining the RRC, MAC, and PHY messages in the REL10 CA. And the CrossCarrierSchedulingConfig-r10 IE defined to indicate the PDSCH start symbol of the NC non-scheduling SCell in the REL 10 RRC Reconfiguration message defined in FIG. 11. However, a value determined for the UE 40 using the EC using any one of the schemes of FIG. 9 to determine the PDSCH start symbol of the BCCC NC used in another network of the same frequency band for the PDSCH start symbol of the EC. You will use RRC Reconfiguration to indicate this.

Looking at a specific example, Figures 12 and 13 show a signal scheme for instructing the PDSCH start symbol of the EC to the UE in the HetNet environment consisting of two carriers of 10MHz (PRB number 50) and 1.4Mhz (PRB number 6), respectively . In the case of using scheme 3 of FIG. 9, PDSCH start symbols on the first two carriers are "3" and "4" by the eNB scheduler, and when the position of the PDSCH start symbol is required due to the increase of the UE activity of the macro cell, macro If the HetNet environment (11a) of the -pico environment proposes a new PDSCH start symbol for its NC through an X2-AP message, the received picocell may also signal the position of its PDSCH start symbol based on UE activity. will be. At this time, each network sends a dedicated signal to the UE 40 using the EC in each network at an appropriate time to apply the position of the new PDSCH start symbol of the EC to the next SFN 0 according to the PDSCH start symbol received from the other network. Must be sent via "11b" applies to the macro-femto HetNet environment. Finally, if the scheme 1 is used, the UE 40 using the EC will always indicate the value of the PDSCH start symbol of the same EC through a dedicated signal, which is the maximum number of PDCCH symbols + 1 of the corresponding carrier, and thus FIG. 12. In the case of FIG. 13, the bands X and Y in the macro cell and the small cell will always be fixedly signaled through the L1 channel and the RRC dedicated channel with PDSCH start symbols of " 3 " and " 4 "

In conclusion, in the present invention, in the case of NC BCCC, which is always managed by each eNB scheduler without an operator's intervention and information exchange between eNBs for indication of PDSCH start symbol of EC, PCFICH always indicates the maximum number of PDCCH symbols of a corresponding carrier. In the case of the associated EC, and in the case of the associated EC, Scheme 1 which always signals the maximum number of PDCCH symbols + 1 of the corresponding carrier to the UE 40 using the EC through an RRC dedicated message is preferred. However, when using Scheme 3 at the operator's choice, we propose the message structure specified in Figs. 8 and 9 in X2-AP and S1-AP.

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. Computer-readable recording media include all kinds of recording devices that store data that can be read by a computer system. Examples of computer-readable recording media include ROM, RAM, CD-ROM, magnetic tape, floppy disks, optical data storage devices, and the like, which are also implemented in the form of carrier waves (for example, transmission over the Internet). Include. The computer readable recording medium can also be distributed over network coupled computer systems so that the computer readable code is stored and executed in a distributed fashion. In addition, functional programs, codes, and code segments for implementing the above embodiments can be easily inferred by programmers in the art to which the present invention belongs.

While the invention has been described in connection with some embodiments herein, it should be understood that various modifications and changes can be made without departing from the spirit and scope of the invention as would be understood by those skilled in the art. something to do. Also, such modifications and variations are intended to fall within the scope of the claims appended hereto.

Claims

As a method for determining a physical downlink shared channel (PDSCH) start symbol of an extension carrier (EC) in heterogeneous manganese,

In determining the PDSCH start symbol of the EC in one network, the PDSCH start symbol determination method of the EC is determined in consideration of the start symbol of a normal carrier (NC) backward compatible component carrier (BCCC) which is the same frequency in the other network.
The method of claim 1,

The one network and the other network using the same or different network interface, ECSCH PDSCH start symbol determination method.
The method of claim 2,

The ECSCH PDSCH start symbol determination method for exchanging the start symbol of the NC BCCC between the macrocell of any one of the network and the other network and the picocell of the other network using an X2 interface.
The method of claim 3,

And a start symbol of an NC BCCC is exchanged between the macrocell and the picocell by adding an information element (IE) related to PDSCH start information to a Release 11 S1-AP Load Information message.
The method of claim 2,

The ECSCH PDSCH start symbol determination method for exchanging the start symbol of the NC BCCC between the macrocell of any one of the network and the other network and the femtocell of the other network using the S1 interface with the Mobility Management Entity (MME).
The method of claim 5,

The ECSCH PDSCH start symbol determination method between the macro cell and the femtocell exchanges the start symbol of the NC BCCC using the eNB / MME X2-AP Transfer message, a newly defined Release 11 S1-AP message.
The method of claim 1,

The one network and the other network to transmit the position of the new PDSCH start symbol according to the start symbol of the NC BCCC received from the other network to the terminal using the EC in each network through a radio resource control (RRC) dedicated message, How ECSCH determines PDSCH start symbol.
The method of claim 1,

And determining the start symbol of the PDSCH with a maximum number of physical downlink control channel (PDCCH) symbols according to the bandwidth and configuration information of the carrier in the network.
As a heterogeneous mobile communication system,

When determining the physical downlink shared channel (PDSCH) start symbol of an EC (Extension Carrier) in one network, the mobile communication, which is determined in consideration of the start symbol of the NC (Normal Carrier) BCCC (Backward Compatible Component Carrier) which is the same frequency in another network system.
The method of claim 9,

And the one network and the other network use the same or different network interfaces.
The method of claim 10,

Between the macrocell of one network and the other network and the picocell of the other network, a start symbol of NC BCCC is exchanged using an X2 interface;

And a start symbol of NC BCCC between the macro cell and the pico cell by adding an information element (IE) related to PDSCH start information to a Release 11 S1-AP Load Information message.
The method of claim 10,

Between the macrocell of one network and the other network and the femtocell of the other network, a start symbol of NC BCCC is exchanged using an S1 interface with a mobility management entity (MME);

A mobile communication system for exchanging a start symbol of an NC BCCC between the macrocell and the femtocell using an eNB / MME X2-AP Transfer message, which is a newly defined REL 11 S1-AP message.
The method of claim 9,

The one network and the other network to transmit the position of the new PDSCH start symbol according to the start symbol of the NC BCCC received from the other network to the terminal using the EC in each network through a radio resource control (RRC) dedicated message, How ECSCH determines PDSCH start symbol.
The method of claim 9,

And determining the start symbol of the PDSCH with a maximum number of physical downlink control channel (PDCCH) symbols according to the bandwidth and configuration information of the carrier in the network.
The method of claim 9,

The heterogeneous network is a HetNet (Heterogeneous Network) environment in which a plurality of base stations overlapping areas of different sizes are used.