WO2016122111A1

WO2016122111A1 - Apparatus and method for performing uplink power control in wireless communication system supporting carrier aggregation

Info

Publication number: WO2016122111A1
Application number: PCT/KR2015/013575
Authority: WO
Inventors: 박동현
Original assignee: 주식회사 아이티엘
Priority date: 2015-01-30
Filing date: 2015-12-11
Publication date: 2016-08-04
Also published as: KR20160094164A; KR102206361B1

Abstract

The present invention relates to an apparatus and a method for performing an uplink power control in a wireless communication system. The present specification discloses a power control method comprising the steps of: receiving an upper layer message including a first TPC index with respect to a PUCCH (PCell) and a second TPC index with respect to a PUCCH (SCell), from a base station; receiving a first TPC order corresponding to the first TPC index and a second TPC order corresponding to the second TPC index, from the base station; controlling a power of the PUCCH (PCell) on the basis of the first TPC order; and controlling a power of the PUCCH (SCell) on the basis of the second TPC order.

Description

Apparatus and method for performing uplink power control in a wireless communication system supporting carrier aggregation

The present invention relates to wireless communication, and more particularly, to an apparatus and method for performing uplink power control in a wireless communication system supporting carrier aggregation.

Carrier Aggregation (CA) supports a plurality of carriers and is also called spectrum aggregation or bandwidth aggregation. Individual unit carriers bound by carrier aggregation are called component carriers (CC). Each component carrier is defined by a bandwidth and a center frequency. Using CA, it is possible to combine a plurality of bands that are physically continuous or non-continuous in the frequency domain, such as to use a logically large band.

CA technology basically requires a primary serving cell (PCell), which serves as an anchor for communication, and a secondary serving cell (SCell). Conventional long term evolution (LTE) has been implemented such that an uplink control channel such as a physical uplink control channel (PUCCH) is transmitted only in a primary serving cell. However, in recent years, the addition of technical features for strengthening CA in the LTE system has been considered. For example, a method in which the PUCCH is transmitted in the secondary serving cell may be mentioned. If the PUCCH is additionally configured in the secondary serving cell in addition to the primary serving cell, a small cell that reduces overhead due to uplink control information (UCI) concentrated in the primary serving cell and provides efficient uplink transmission is provided. It can help you with deployment. As a result, it is possible to implement reliable uplink control signal transmission.

Meanwhile, the uplink transmission power control of the terminal is a technique for solving interference or attenuation according to the distance between the terminal and the base station, and is also called a transmission power control (TPC) command. The TPC command is signaling transmitted from the base station to the terminal to perform power control of a PUCCH or a physical uplink shared channel (PUSCH). The TPC command allows the base station to receive an uplink signal with a uniform power strength.

TPC commands for PUCCH or PUSCH are currently applied to both CA-supported terminals and CA-unsupported terminals through a common control region of the main serving cell, but TPC has not yet been applied for PUCCH (SCell) or PUSCH, which is a newly added feature in LTE systems. It is not discussed whether or not the order should be applied.

An object of the present invention is to provide an apparatus and method for performing uplink power control in a wireless communication system supporting carrier aggregation.

Another technical problem of the present invention is to provide a power control apparatus and method for uplink power control to effectively support the CA of the LTE system.

Another technical problem of the present invention is to provide a power control apparatus and method for a PUCCH or a PUSCH configured in a secondary serving cell like a main serving cell in a wireless communication system supporting CA.

According to an aspect of the present invention, there is provided a power control method by a terminal supporting carrier aggregation based on a plurality of serving cells. The method includes a first transmission power control (TPC) index for an uplink control channel (hereinafter referred to as PUCCH (PCell)) on a primary serving cell (PCell) and a secondary serving cell. : Receiving from the base station an upper layer message including a second TPC index on an uplink control channel (hereinafter called PUCCH (SCell)) on a SCell, a first TPC command corresponding to the first TPC index and the first TPC index; Receiving a second TPC command corresponding to a 2 TPC index from the base station, and controlling the power of the PUCCH (PCell) based on the first TPC command, and based on the second TPC command, the SCC (SCell) Controlling the power of n).

According to another aspect of the present invention, a power control apparatus supporting carrier aggregation based on a plurality of serving cells is provided. The apparatus includes an RF unit for receiving an upper layer message and a TPC command message from a base station, and an uplink control channel (hereinafter referred to as PUCCH (PCell)) on a primary serving cell (PCell) from the received message. A first transmission power control (TPC) index and a second TPC index for an uplink control channel (hereinafter called PUCCH (SCell)) on a secondary serving cell (SCell) are identified, and the first Confirming a first TPC command corresponding to a TPC index and a second TPC command corresponding to the second TPC index, controlling power of the PUCCH (PCell) based on the first TPC command, and performing the second TPC command Based on the processor to control the power of the PUCCH (SCell).

The CA may be effectively supported by performing power control on the PUCCH or the PUSCH configured in the secondary serving cell.

1 is a block diagram showing a wireless communication system to which the present invention is applied.

2 is an example of a TPC command applied to the channel structure of the serving cell according to the present invention.

3 is a flowchart in which uplink power control is performed according to an example of the present invention.

4 illustrates an example of a correspondence relationship between a TPC index and a group TPC command.

5 is a diagram illustrating a method of transmitting and monitoring a group TPC command according to an example of the present invention.

6 is a diagram illustrating a method for transmitting and monitoring a group TPC command according to another example of the present invention.

7 is a view for explaining a method for transmitting and monitoring a group TPC command according to another embodiment of the present invention.

8 is a diagram illustrating a method of transmitting and monitoring a group TPC command according to another example of the present invention.

9 illustrates an example of a correspondence relationship between a TPC index and a group TPC command, according to an exemplary embodiment.

10 is a block diagram illustrating a terminal and a base station according to an embodiment.

Hereinafter, some embodiments will be described in detail with reference to the accompanying drawings. In adding reference numerals to the components of each drawing, it should be noted that the same reference numerals are assigned to the same components as much as possible even though they are shown in different drawings. In addition, in describing the embodiments of the present specification, when it is determined that a detailed description of a related well-known configuration or function may obscure the gist of the present specification, the detailed description thereof will be omitted.

In addition, the present specification describes a wireless communication network, the operation performed in the wireless communication network is performed in the process of controlling the network and transmitting data in the system (for example, the base station) that is in charge of the wireless communication network, or the corresponding wireless Work may be done at the terminal coupled to the network.

Referring to FIG. 1, the wireless communication system 10 is widely deployed to provide various communication services such as voice and packet data. The wireless communication system 10 includes at least one base station (BS) 11. Each base station 11 provides a communication service for a specific geographic area or frequency area and may be called a site. The site may be divided into a plurality of

regions

15a, 15b, and 15c, which may be called sectors, and the sectors may have different cell IDs.

The UE 12 may be fixed or mobile and may have a mobile station (MS), a mobile terminal (MS), a mobile terminal (MT), a user terminal (UT), a subscriber station (SS), a wireless device, or a PDA. (personal digital assistant), wireless modem (wireless modem), a handheld device (handheld device) may be called other terms. The base station 11 generally refers to a station communicating with the terminal 12, and includes an evolved-nodeb (eNodeB), a base transceiver system (BTS), an access point, an femto base station, a femto eNodeB, and a household It may be called other terms such as a base station (Home eNodeB: HeNodeB), a relay, a remote radio head (RRH), and the like.

Cells

15a, 15b, and 15c should be interpreted in a comprehensive sense indicating some areas covered by the base station 11, and encompass all of the various coverage areas such as megacells, macrocells, microcells, picocells, and femtocells. to be.

Hereinafter, downlink refers to a communication or communication path from the base station 11 to the terminal 12, and uplink refers to a communication or communication path from the terminal 12 to the base station 11. . In downlink, the transmitter may be part of the base station 11 and the receiver may be part of the terminal 12. In uplink, the transmitter may be part of the terminal 12 and the receiver may be part of the base station 11. There is no limitation on the multiple access scheme applied to the wireless communication system 10. Code Division Multiple Access (CDMA), Time Division Multiple Access (TDMA), Frequency Division Multiple Access (FDMA), Orthogonal Frequency Division Multiple Access (OFDMA), Single Carrier-FDMA (SC-FDMA), OFDM-FDMA, OFDM-TDMA For example, various multiple access schemes such as OFDM-CDMA may be used.

Layers of a radio interface protocol between the terminal 12 and the base station 11 may be divided into a first layer L1, a second layer L2, and a third layer L3. Among them, the physical layer belonging to the first layer provides an information transfer service using a physical channel.

The physical layer is connected to a higher layer, a media access control (MAC) layer, through a transport channel. Data is transmitted through a transport channel between the MAC layer and the physical layer. Transport channels are classified according to how data is transmitted over the air interface. In addition, data is transmitted through a physical channel between different physical layers (that is, between a physical layer of a terminal and a base station). The physical channel may be modulated by an orthogonal frequency division multiplexing (OFDM) scheme and utilizes space generated by time, frequency, and a plurality of antennas as radio resources.

For example, a physical downlink control channel (PDCCH) of a physical channel informs a terminal of resource allocation of a PCH (Paging CHannel) and DL-SCH (DownLink Shared CHannel) and HARQ (Hybrid Automatic Repeat Request) information related to the DL-SCH, The terminal may carry an uplink scheduling grant informing of resource allocation of uplink transmission. Physical Uplink Shared Channel (PDSCH) carries DL-SCH including downlink data. In addition, the Physical Uplink Control CHannel (PUCCH) carries uplink control information such as HARQ ACK / NACK, scheduling request, and CQI for downlink transmission. In addition, the PUSCH (Physical Uplink Shared CHannel) carries a UL-SCH (Uplink Shared CHannel) including uplink data. If necessary according to the configuration and request of the base station, the PUSCH may include channel state information (CSI) information such as HARQ ACK / NACK and CQI.

Hereinafter, a multiple carrier system includes a system supporting carrier aggregation (CA). A serving cell may be defined as an element frequency band that may be aggregated by a CA based on a multiple component carrier system. The serving cell includes a primary serving cell (PCell) and a secondary serving cell (SCell). The primary serving cell is one that provides security input and non-access stratum (NAS) mobility information in a radio resource control (RRC) connection or re-establishment state. It means a serving cell. According to the capabilities of the terminal, at least one cell may be configured to form a set of serving cells together with the main serving cell, wherein the at least one cell is called a secondary serving cell. The set of serving cells configured for one terminal may consist of only one main serving cell or one main serving cell and at least one secondary serving cell. Each serving cell may be operated in an activated or deactivated state.

Uplink transmission power control of the terminal is performed by a TPC command. The TPC command is signaling transmitted by the base station to the terminal to perform power control of the PUCCH or the PUSCH. As the PUCCH (SCell) is introduced in the LTE system, if a PUCCH (SCell) is additionally configured to the UE where the CA is configured, some uplink control information (UCI) transmitted only through the existing PUCCH (PCell) It may be sent to PUCCH (SCell). In addition, UCI information may be sent on a PUSCH (SCell) according to the existence of an uplink grant. Accordingly, in order to effectively support a PUCCH (SCell) based CA, power control regarding the PUCCH (SCell) or the PUSCH is required like the main serving cell.

Referring to FIG. 2, a main serving cell (PCell) and a secondary serving cell (SCell) are configured as CAs in a terminal. The PUCCH region and the PUSCH region are divided on the frequency axis of each serving cell. A signal of the PUCCH region and a signal of the PUSCH region may be controlled by its transmit power by a group TPC command. The group TPC command is a TPC command for a terminal group. That is, the group TPC command includes a TPC command for each of the plurality of terminals. When at least one of the plurality of terminals supports the PUCCH (SCell), the group TPC command may include a TPC command of the primary serving cell and the secondary serving cell for the same terminal. Signals of the PUCCH region whose power is controlled by the group TPC command include periodic CSI reporting, HARQ-ACK, SR, and the like.

Specifically, the operation of applying the group TPC command for PUCCH / PUSCH transmission power control in each serving cell will be described. PUCCH (PCell) is controlled by TPC command 1 and PUCCH (SCell) is controlled by TPC command 2. (In this embodiment, the TPC command for the PUSCH is omitted for convenience).

Here, the TPC commands 1 and 2 may be included in one group TPC command or may be included in different group TPC commands. In other words, the TPC command 1 and the TPC command 2 may be provided by one downlink control information (DCI) or may be provided by different DCIs. The DCI is transmitted to the UE through the PDCCH in the common search space.

In this embodiment, it is assumed that one main serving cell and one secondary serving cell are configured in one terminal, and it is assumed that there are two TPC commands. However, this is only an example, and one terminal has a secondary serving cell configured with a PUCCH. There may be more than one, and thus the number of TPC commands may increase. Hereinafter, the group TPC command will be briefly described as controlling a PUCCH (PCell) (hereinafter referred to as PUCCH (PCell)) and a PUCCH (SCell) (hereinafter referred to as PUCCH (SCell)), but the group TPC command includes a main serving cell and a PUCCH ( Of course, the PUSCH can be controlled as well as the SCell.

In the following, the method of performing uplink power control by a group TPC command according to the present invention is posted in detail.

Referring to FIG. 3, the base station transmits a message of a higher layer that provides a TPC index to the terminal (S300). The TPC index determines an index to a TPC command for the terminal (TPC index determines an index to TPC command for a given UE). The TPC index may have an N or M value, and N and M are distinguished based on the DCI format. For example, in case of DCI format 3, the TPC index has an N value, and in case of DCI format 3A, the TPC index has an M value. The upper layer message may be an RRC message. For example, the RRC message is TPC-PDCCH-Config, which is used to specify indexes and RNTIs for power control of PUCCH and PUSCH. Power control of the PUCCH and PUSCH may be set or released using TPC-PDCCH-Config.

In the present embodiment, a plurality of TPC indexes for a terminal may be assigned to a primary serving cell and a secondary serving cell of one terminal, and may correspond to respective TPC commands for the primary serving cell and the secondary serving cell. As an example, the TPC index for the UE may include a first TPC index for PUCCH (PCell) and a second TPC index for PUCCH (SCell). The second TPC index may be referred to as an index added to the first TPC index. The upper layer message (eg, RRC message or TPC-PDCCH-Config) for setting both the first TPC index and the second TPC index may have a structure as shown in the following table.

Table 1

-ASN1START

TPC-PDCCH-Config :: = CHOICE {

release NULL,

setup SEQUENCE {

tpc-RNTI BIT STRING (SIZE (16)),

tpc-Index [TPC-Index, TPC-Index_r13]

}

TPC-Index :: = CHOICE {

indexOfFormat3 INTEGER (1..15),

indexOfFormat3A INTEGER (1..31)

TPC-Index_r13 (SCell PUCCH) :: = CHOICE {

indexOfFormat3 INTEGER (1..15),

indexOfFormat3A INTEGER (1..31)

}

-ASN1STOP

Referring to Table 1, the tpc-Index field indicates [TPC-Index, TPC-Index_r13]. Here, the TPC-Index field indicates a first TPC index and has an indexOfFormat3 or indexOfFormat3A value according to the DCI format. indexOfFormat3 is a natural number of any one of 1 to 15, and indexOfFormat3A is a natural number of any one of 1 to 31. Meanwhile, the TPC-Index_r13 field indicates the second TPC index and has an indexOfFormat3 or indexOfFormat3A value according to the DCI format. indexOfFormat3 is a natural number of any one of 1 to 15, and indexOfFormat3A is a natural number of any one of 1 to 31.

The terminal receiving the higher layer message uses the TPC-Index field as the TPC index for the TPC command for the PUCCH (PCell), and uses the TPC-Index_r13 field as the TPC index for the TPC command for the PUCCH (SCell). do. That is, the TPC index for the primary serving cell and the TPC index for the secondary serving cell may be distinguished. The first TPC index and the second TPC index may be set independently or separately by the base station, and may be set to be associated with or the same as each other. The UE may perform power control for PUCCH (PCell) and PUCCH (SCell) transmission using two TPC indexes. The TPC-Index_r13 field may be replaced with a name including a term regarding a secondary serving cell such as TPC-Index_SCell. Here, the PUCCH for the primary serving cell and the PUCCH for the secondary serving cell may belong to one UE.

If the base station provides a plurality of TPC indexes set in step S300 to the terminal, the terminal completes the TPC settings for the primary serving cell and secondary serving cell.

Thereafter, the base station transmits a group TPC command to the terminal (S305). The group TPC command is included in the DCI and transmitted. The length and contents of the group TPC command may differ depending on which DCI format is used for transmitting the group TPC command. Same as "TPC command number 1, TPC command number 2, ..., TPC command number N" for DCI format 3, "TPC command number 1, TPC command number 2, ..., TPC command" for DCI format 3A number M ". N and M are the parameters described in Table 1. In the present invention, both

DCI formats

3 and 3A may be used to transmit a group TPC command, and other formats of DCI may also be used.

In order to allow the terminal or the base station to perform both power control for the PUCCH (PCell) and power control for the PUCCH (SCell), the group TPC command of various embodiments may be used in step S305.

As an example, the group TPC command is a single group TPC command, in which a single group TPC command is included in one DCI. The DCI including the single group TPC command is transmitted mapped to the PDCCH scrambled by the TPC-PUCCH RNTI. In addition, the DCI including the single group TPC command is transmitted on the primary serving cell (see FIG. 5).

As an example, an example of the correspondence between the TPC index and the group TPC command is shown in FIG. 4. Referring to FIG. 4, both DCI format 3 and DCI format 3A have a specific length, which is referred to as 11 bits in FIG. 4.

In the example of DCI format 3, UE1, UE2, UE3 perform PUCCH power control by one group TPC command. Only UE1 of UE1 to UE3 is configured with PUCCH (SCell), so that an additional TPC command (2 bits) for power control of PUCCH (SCell) is allocated to UE1. PUCCH (SCell) is not configured in the remaining UE2 and UE3. Every two bits in DCI format 3 are one TPC command, with each TPC command sequentially corresponding to a specific TPC index. The first and second bits (or TPC command 1) correspond to TPC index 1, the third and fourth bits (or TPC command 2) correspond to TPC index 2, and the fifth and sixth bits (or TPC command 3) Corresponds to TPC index 3, and the 7,8th bit (or TPC command 4) corresponds to TPC index 4. And, which UE or which serving cell each TPC index relates to is previously set by signaling as shown in Table 1. For example, TPC index 1 relates to PUCCH (PCell) of UE1 and TPC index 4 relates to PUCCH (SCell) of UE1. This is because only UE1 is configured with a PUCCH (SCell), so that an additional TPC command (2 bits) for power control of the PUCCH (SCell) is allocated to UE1.

Next, in the example of DCI format 3A, UE1 to UE6 perform PUCCH / PUSCH power control by one group TPC command. PUCCH (SCell) is configured in UE1 and UE6 among UE1 to UE6, and an additional TPC command (1 bit) for power control of PUCCH (SCell) is allocated to UE1 and UE6, respectively. Every 1 bit in DCI format 3A is a TPC command, with each TPC command sequentially corresponding to a specific TPC index. 1st bit (or TPC command 1), 2nd bit (or TPC command 2), 3rd bit (or TPC command 3), 4th bit (or TPC command 4), ..., Mth bit (or TPC Command M) corresponds to TPC index 1, TPC index 2, TPC index 3, TPC index 4, ..., and TPC index M, respectively. And, which UE or which serving cell each TPC index relates to is previously set by signaling as shown in Table 1. For example, TPC index 1 relates to PUCCH (PCell) of UE1 and TPC index 3 relates to PUCCH (SCell) of UE1. In addition, TPC index 7 relates to PUCCH (PCell) of UE6, and TPC index 8 relates to PUCCH (SCell) of UE6.

Referring again to FIG. 3, as another example, the group TPC command is a multi-group TPC command, which is a first group TPC command (power control for PUCCH (PCell)) and a second group TPC command (power for PUCCH (SCell)). Controls) are included in different DCIs. Both the first DCI including the first group TPC command and the second DCI including the second group TPC command are transmitted on the primary serving cell (see FIGS. 6 and 7).

As another example, the group TPC command is a multi-group TPC command, wherein the first group TPC command (power control for PUCCH (PCell)) and the second group TPC command (power control for PUCCH (SCell)) are different from each other. Included in The first DCI including the first group TPC command is transmitted on the primary serving cell, and the second DCI including the second group TPC command is transmitted on the secondary serving cell (see FIG. 8).

The terminal receives the DCI including the group TPC command, and performs power control of the PUCCH and the PUSCH in the primary serving cell and the secondary serving cell based on the group TPC command (S310). Specifically, the power control according to the group TPC command according to the present invention may be performed based on an accumulative power control mode. For example, when the terminal receives a group TPC command for the secondary serving cell configured with the PUCCH, the terminal accumulates the power control value of the PUCCH according to the group TPC command to the previous value.

For example, the terminal may perform the accumulation operation based on the following equation.

Equation 1

Is used as a value corresponding to the group TPC command indicated to the terminal through the DCI format 3 / 3A, and the value may be indicated through Tables 2 and 3 below.

TABLE 2

TPC Command Field in DCI Format 3A	[dB}
0	-One

TABLE 3

TPC command field in DCI format 1A / 1B / 1D / 1 / 2A / 2B / 2C / 2D / 2/3	[dB}
0	-One
One	0
2	One
3	3

Referring to Table 2 and Table 3, Table 2 shows the group TPC command in case of DCI format 1A / 1B / 1D / 1 / 2A / 2B / 2C / 2D / 2/3.

Table 3 shows the mapping relationship with values, and Table 3 shows the group TPC command in case of DCI format 3A.

Represents a mapping relationship with a value.

In Equation 1, g (i) represents a current PUCCH power control adjustment state. In FDD, M = 1, and in TDD, M is the number of downlink subframes associated with one PUCCH transmission, and its value may vary depending on downlink HARQ timing. k _m is a value corresponding to downlink HARQ timing and indicates each of the associated downlink subframes. If _m is the current subframe, it means nk _m downlink subframe. The k _m value is indicated, for example, in Table 4 below.

Table 4

UL / DL setting	Subframe n
UL / DL setting	0	One	2	3	4	5	6	7	8	9
0	-	-	6	-	4	-	-	6	-	4
One	-	-	7, 6	4	-	-	-	7, 6	4	-
2	-	-	8, 7, 4, 6	-	-	-	-	8, 7, 4, 6	-	-
3	-	-	7, 6, 11	6, 5	5, 4	-	-	-	-	-
4	-	-	12, 8, 7, 11	6, 5, 4, 7	-	-	-	-	-	-
5	-	-	13, 12, 9, 8, 7, 5, 4, 11, 6	-	-	-	-	-	-	-
6	-	-	7	7	5	-	-	7	7	-

The terminal transmits the PUCCH and / or PUSCH to the base station on the primary serving cell and / or secondary serving cell based on the power controlled by step S310 (S315).

Hereinafter, various embodiments related to the transmission of the group TPC command posted in step S305 will be described in more detail with reference to the accompanying drawings.

Referring to FIG. 5, a first TPC command for a PUCCH (PCell) and a second TPC command for a PUCCH (SCell) are included in a single group TPC command and mapped to one DCI. That is, this embodiment shares one DCI for power control of two PUCCHs (PCells) and PUCCHs (SCells). The DCI including such a single group TPC command may be as shown in FIG. 4, for example.

DCI including a single group TPC command according to the present embodiment is mapped and transmitted to a PDCCH scrambled by TPC-PUCCH # 0 (RNTI). In addition, PDCCH (PDCCH with TPC-PUCCH RNTI) related to the single group TPC command is mapped to a common search space (CSS) on the main serving cell. From the operation point of view of the base station and the terminal, the base station first generates one DCI for power control of two PUCCH (PCell) and PUCCH (SCell), and converts the PDCCH including the generated DCI into TPC-PUCCH RNTI. It is scrambled (exactly scrambled in the CRC bit), and the scrambled PDCCH is mapped to CSS of the main serving cell and transmitted to the terminal. And the UE monitors the CSS of the main serving cell in order to receive a TPC command to the PUCCH (SCell). In this regard, the present embodiment is different from the terminal configured with two dual connectivity (DCS) monitoring two CSS on PCell and PSCell (CSS).

Examples of PDCCHs mapped to common search spaces include PDCCH scrambled with Random Access-Radio Network Temporary Identifier (RA-RNTI) and PDCCH scrambled with C-RNTI (common-RNTI). C-RNTI), PDCCH scrambled with Temporary C-RNTI, PDCCH scrambled with TPC-PUSCH-RNTI, PDCCH scrambled with eIMTA-RNTI (PDCCH with eIMTA-RNTI), PDCCH scrambled with SPS-RNTI, PDCCH with P-RNTI scrambled with P-RNTI, PDCCH scrambled with SI-RNTI RNTI).

Referring to FIG. 6, a first group TPC command for PUCCH (PCell) and a second group TPC command for PUCCH (SCell) are included in different DCIs. The first DCI including the first group TPC command and the second DCI including the second group TPC command are both transmitted on the primary serving cell. The first DCI is mapped to PDCCH1 scrambled with TPC-PUCCH # 0 RNTI, and the second DCI is mapped to PDCCH2 scrambled with TPC-PUCCH # 0 RNTI and transmitted. That is, one TPC-PUCCH RNTI value is commonly applied to two PDCCHs having different TPC commands (or DCIs). Also, both PDCCH1 and PDCCH2 are mapped to CSS on the main serving cell. Since PDCCH1 and PDCCH2 are mapped to the same CSS and the same TPC-PUCCH RNTI value is applied, information for distinguishing PDCCH1 and PDCCH2 is necessary.

As an example, a carrier indicator field (CIF) may be used to distinguish between PDCCH1 and PDCCH2. For example, the CIF may be included in the second DCI related to the PUCCH (SCell). In other words, CIF may be used to distinguish between the first DCI and the second DCI. In other words, the CIF may be used to distinguish the first group TPC command from the second group TPC command. Accordingly, the base station can configure cross-carrier scheduling through RRC signaling to terminals configured with PUCCH (SCell) in the common search space similarly to cross carrier scheduling that can be configured in the UE-specific search space. Here, the CIF value activated in the DCI serves as an indicator indicating only the DCI information for the PUCCH (SCell), not the serving cell to which the PDSCH or the PUSCH is transmitted as in the UE-specific search space. Therefore, only 1 bit can be used as the CIF value. Of course, when there are two or more secondary serving cells configured with PUCCH (SCell), the bit value for the CIF value may increase accordingly. For example, when the CIF value of 1 bit is 0, the UE recognizes that the corresponding DCI provides a group TPC command for PUCCH (SCell). On the other hand, if a 1-bit CIF value is 1, it is reserved. Accordingly, cross-carrier scheduling in the common search space is set through RRC signaling, and is indicated (or activated) by a 3-bit CIF field or a 1-bit CIF field based on the setting of the RRC signaling. All unused fields in the CIF field are reserved. And the UE must monitor the CSS of the main serving cell in order to receive the group TPC command for the PUCCH (SCell). The following is an RRC signaling information element for cross carrier scheduling. In order to indicate cross-carrier scheduling on the primary serving cell, the schedulingCellId value should be the serving cell index of the primary serving cell (that is, 0). And cif-presence is activated and only 3 bits or 1 bit is activated in DCI (format 3 / 3A).

Table 5

-ASN1START

CrossCarrierSchedulingConfig-r10 :: = SEQUENCE {

schedulingCellInfo-r10 CHOICE {

own-r10 SEQUENCE {-No cross carrier scheduling

cif-Presence-r10 BOOLEAN

},

other-r10 SEQUENCE {-Cross carrier scheduling

schedulingCellId-r10 ServCellIndex-r10,

pdsch-Start-r10 INTEGER (1..4)

}

-ASN1STOP

From the operation point of view of the base station and the terminal, the base station first generates a first DCI for power control of the PUCCH (PCell), and generates a second DCI for power control of the PUCCH (SCell). At this time, the base station includes a CIF indicating the primary serving cell in the second DCI. The base station scrambles PDCCH1 including the first DCI to TPC-PUCCH RNTI and scrambles PDCCH2 including the second DCI to TPC-PUCCH RNTI. The base station maps both the scrambled PDCCH1 and PDCCH2 to the CSS of the main serving cell and transmits them to the terminal. And the UE monitors the CSS of the main serving cell in order to receive a TPC command to the PUCCH (SCell).

According to this embodiment, cross-carrier scheduling is possible not only for PDCCHs mapped on UE-specific search space (USS) but also for PDCCHs mapped on CSS. In addition, by using CIF, a separate RNTI does not need to be introduced to distinguish between PDCCH1 and PDCCH2.

7 is a view for explaining a method for transmitting and monitoring a group TPC command according to another embodiment of the present invention. This is different in that the new RNTI is used for the PDCCH2 transmitted on the CSS of the main serving cell when compared with FIG. 6.

Referring to FIG. 7, a first group TPC command for PUCCH (PCell) and a second group TPC command for PUCCH (SCell) are included in different DCIs. The first DCI including the first group TPC command and the second DCI including the second group TPC command are both transmitted on the primary serving cell. The first DCI is mapped to PDCCH1 scrambled with TPC-PUCCH # 0 RNTI, and the second DCI is mapped to PDCCH2 scrambled with TPC-PUCCH-SCell RNTI and transmitted. That is, different RNTI values are applied to two PDCCHs having different TPC commands (or DCIs). Of course, the TPC_PUCCH-SCell RNTI newly defined in the present embodiment for power control of the PUCCH (SCell) may be replaced with another term that performs the same function.

On the other hand, both PDCCH1 and PDCCH2 are mapped to CSS on the main serving cell. Although PDCCH1 and PDCCH2 are mapped to the same CSS, different RNTI values are applied to scramble of the PDCCH, so that no separate information for distinguishing PDCCH1 and PDCCH2 is necessary. That is, since different RNTI values and different TPC index values are set and transmitted on the PDCCH, there is no need to set a separate CIF value.

From the operation point of view of the base station and the terminal, the base station first generates a first DCI for power control of the PUCCH (PCell), and generates a second DCI for power control of the PUCCH (SCell). The base station scrambles PDCCH1 including the first DCI to TPC-PUCCH RNTI and scrambles PDCCH2 including the second DCI to TPC-PUCCH-SCell RNTI. The base station maps both the scrambled PDCCH1 and PDCCH2 to the CSS of the main serving cell and transmits them to the terminal. And the UE monitors the CSS of the primary serving cell using the TPC-PUCCH-SCell RNTI to receive a TPC command to the PUCCH (SCell).

Referring to FIG. 8, a first group TPC command for PUCCH (PCell) and a second group TPC command for PUCCH (SCell) are included in different DCIs. The first DCI including the first group TPC command is transmitted on the primary serving cell, and the second DCI including the second group TPC command is transmitted on the secondary serving cell.

The first DCI is mapped to PDCCH1 scrambled with TPC-PUCCH RNTI, and PDCCH1 is mapped to CSS on the main serving cell. The second DCI is mapped to PDCCH2 scrambled with TPC-PUCCH RNTI, and PDCCH2 is mapped to CSS on the secondary serving cell.

In order for the UE to receive the PDCCH2, it must first be known that the PDCCH2 is mapped to the CSS on the secondary serving cell. The mapping of the PDCCH2 to the CSS on the secondary serving cell may be implied by the base station and the terminal, or may be explicitly informed by the base station to the terminal.

As an example, the UE may transmit capability information indicating that the UE can support a multimedia broadcast multicast service (MBMS) to the base station. The base station receiving the capability information may map PDCCH2 to CSS on the secondary serving cell. have. That is, the performance information may be information that implicitly informs the base station to transmit PDCCH2 by mapping it to CSS on the secondary serving cell. In addition, the terminal transmitting the capability information may implicitly know that it is necessary to monitor the CSS on the secondary serving cell in order to receive a group TPC command related to the PUCCH (SCell).

The reason for such an operation is as follows. A physical channel related to MBMS, a PMCH (Phsycal MBMS Channel) is transmitted on a carrier (or secondary serving cell) other than the primary serving cell, and PDCCH with M-RNTI (PDCCH) necessary for decoding the PMCH is not a primary serving cell. PMCH is mapped to the CSS of the carrier (or secondary serving cell) to be transmitted. Therefore, in order to receive the MBMS, the MBMS capable terminal must monitor the CSS on the secondary serving cell in which the PMCH is transmitted, not the main serving cell. Since the UE needs to monitor the CSS of the secondary serving cell in order to receive the MBMS, it is possible to monitor the PDCCH2 regarding the group TPC command on the PUCCH (SCell) together in the CSS on the secondary serving cell. Here, the secondary serving cell includes an uplink component carrier (UL CC) for transmitting a PUCCH (SCell) and a downlink component carrier (DL CC) connected to the UL CC and SIB-2. Accordingly, the UE monitors the PDCCH scrambled with the TPC-PUCCH RNTI in the CSS on the DL CC.

In order to monitor the CSS on the secondary serving cell in order for the terminal to receive PDCCH2 according to the present embodiment, i) transmit performance information indicating that the terminal supports MBMS to the base station, ii) PUCCH (SCell) is configured in the terminal To be. In other words, when the terminal can support the MBMS and can support the PUCCH (SCell), the terminal can monitor the CSS on the secondary serving cell to receive a group TPC command (or DCI). In another aspect, when a UE having a UE capability corresponding to mbms-SCell supports a PUCCH (SCell), and it is set by a base station, the UE sends a group TPC command for power control of the PUCCH (SCell). Monitor the CSS on the DL CC (SCell) associated with the UL CC (SCell) and the SIB-2 link to which the PUCCH (SCell) is transmitted to receive the.

Performance information indicating that the MBMS can be supported (mbms-SCell-r11) may be defined as shown in Table 6 below. It may be included in parameter information related to MBMS (MBMS-Parameters-r11).

Table 6

MBMS-Parameters-r11 :: = SEQUENCE {

mbms-SCell-r11 ENUMERATED {supported} OPTIONAL,

mbms-NonServingCell-r11 ENUMERATED {supported} OPTIONAL

}

Referring to Table 6, parameter information related to MBMS (MBMS-Parameters-r11) may be information included in UE-EUTRA-Capability IE. mbms-SCell-r11 is performance information indicating that MBMS can be supported in a secondary serving cell, and may be optionally included in parameter information related to MBMS, and when mbms-SCell-r11 indicates {supported}. The terminal indicates that the secondary serving cell can support reception of the MBMS.

If the performance information indicating that the MBMS can be supported is displayed as "supported", the terminal expects to monitor the CSS on the secondary serving cell in order to receive a group TPC command on the PUCCH (SCell) later. This is because the terminal can already monitor the CSS on the secondary serving cell or non-serving cell (non-ServingCell).

As another example, regardless of whether the UE supports MBMS, when the UE supports PUCCH (SCell) (or when PUCCH (SCell) is configured), the UE implicitly applies CSS on the secondary serving cell to receive PDCCH2. Can be monitored. In this case, the base station also implicitly maps PDCCH2 to CSS on the secondary serving cell and transmits it to the terminal.

Referring to FIG. 9, the base station may set a TPC index value set by higher layer signaling to a value common to each terminal. In other words, unlike FIG. 4, the TPC index value may be shared without setting the TPC index value differently for each UE. This method is valid only for new terminals configured with a PUCCH (SCell) and is indicated in the same DCI format as a legacy terminal (FIG. 5) or when a PUCCH (SCell) is designated through another DCI (FIG. 5). 6, 7 or 8) can be applied. The specific method is as follows.

The legacy terminal UE 2/4/5 is configured as in the prior art, and the new terminals UE 1/7/8 and UE6 / 10/11/12 are each set to the same value of the TPC index. The base station may provide a power value by distinguishing the time between the terminals (e.g. UE1 / 7/8 or UE6 / 10/11/12). The equation for classifying time is as follows.

Equation 2

Referring to Equation 2, K value is the number of terminals sharing one TPC index. In this example, K = 3 or K = 4. For example, in UE 1/7/8 where K = 3, the base station sets i = 0 to UE1, i = 1 for UE7, and i = 2 for UE8, so that three UEs are provided per subframe. Different TPC index values can be provided to the. Each terminal can share a bit value in the same TPC field through a subframe corresponding to each i value. According to this, the group TPC command value can be provided by utilizing the TPC index value more efficiently.

Referring to FIG. 10, the terminal 1000 includes a processor 1010, an RF unit 1020, and a memory 1025. The memory 1025 is connected to the processor 1010 and stores various information for driving the processor 1010. The RF unit 1020 is connected to the processor 1010 and transmits and / or receives a radio signal.

The RF unit 1020 receives a message of a higher layer that gives a TPC index from the base station 1050. The definition and function of the TPC index is as described in step S300. The upper layer message may be an RRC message. For example, the RRC message is TPC-PDCCH-Config, as shown in Table 1, and is used to specify indexes and RNTIs for power control of PUCCH and PUSCH. Power control of the PUCCH and PUSCH may be set or released using TPC-PDCCH-Config. The first TPC index and the second TPC index may be set independently or individually by the processor 1060 of the base station 1050, or may be set to be associated with or the same as each other.

The processor 1010 implements the functions, processes, and / or methods of the terminal proposed in FIGS. 2 to 8 of the present specification.

Specifically, when the RF unit 1020 receives the higher layer message, the processor 1010 completes the TPC setting for the primary serving cell and the secondary serving cell. The processor 1010 uses the TPC-Index field as the TPC index for the TPC command for the PUCCH (PCell), and uses the TPC-Index_r13 field as the TPC index for the TPC command for the PUCCH (SCell). That is, the processor 1010 may distinguish the TPC index of the primary serving cell from the TPC index of the secondary serving cell. The processor 1010 may perform power control for PUCCH (PCell) and PUCCH (SCell) transmission using two TPC indexes.

In addition, the RF unit 1020 receives a group TPC command from the base station 1050. The group TPC command is included in the DCI and received. Definitions, functions, and structures regarding the group TPC command are as described in step S305. In order to the processor 1010 to perform both power control for the PUCCH (PCell) and power control for the PUCCH (SCell), the group TPC command of various embodiments may be used in step S305. 5 to 8 may be used as a method of transmitting a group TPC command.

In one example, the processor 1010 monitors the CSS of the primary serving cell to receive a TPC command to the PUCCH (SCell).

As another example, the processor 1010 monitors the CSS of the primary serving cell using the TPC-PUCCH-SCell RNTI to receive a TPC command to the PUCCH (SCell).

As another example, the processor 1010 may generate performance information indicating that the MBMS can be supported and transmit the performance information to the RF unit 1020, and the RF unit 1020 may transmit a message as shown in Table 2 to the base station 1050. . The processor 1010 monitors the CSS of the secondary serving cell to receive the MBMS, but monitors the PDCCH2 regarding the group TPC command on the PUCCH (SCell) together in the CSS on the secondary serving cell.

As another example, the processor 1010 implicitly selects the PDCCH2 when the terminal 1000 supports the PUCCH (SCell) (or when the PUCCH (SCell) is configured), regardless of whether the terminal 1000 supports MBMS. You can monitor the CSS on the secondary serving cell to receive it.

Upon receiving the group TPC command by monitoring, the processor 1010 performs power control of the PUCCH and the PUSCH in the primary and secondary serving cells based on the group TPC command. In detail, the processor 1010 may perform power control on the PUCCH of the secondary serving cell based on an cumulative power control mode. For example, when a group TPC command for the secondary serving cell configured with the PUCCH is received, the processor 1010 accumulates the power control value of the PUCCH according to the group TPC command to the previous value.

The RF unit 1065 transmits the PUCCH (PCell) and / or the PUCCH (SCell) from the terminal 1000 to the base station 1050 according to the power controlled by the group TPC command.

The base station 1050 includes a memory 1055, a processor 1060, and a radio frequency (RF) unit 1065. The memory 1055 is connected to the processor 1060 and stores various information for driving the processor 1060. The RF unit 1065 is connected to the processor 1060 and transmits and / or receives a radio signal. In detail, the RF unit 1065 transmits a message of a higher layer that provides a TPC index to the terminal 1000. In addition, the RF unit 1065 transmits a group TPC command to the terminal 1000 on the main serving cell and / or the secondary serving cell. For example, the RF unit 1065 may map a DCI including a single group TPC command to the PDCCH scrambled by the TPC-PUCCH RNTI and transmit it on the primary serving cell. In addition, the RF unit 1065 receives performance information related to MBMS shown in Table 2 from the terminal 1000. In addition, the RF unit 1065 receives a PUCCH (PCell) and / or a PUCCH (SCell) from the terminal 1000.

The processor 1060 implements the functions, processes, and / or methods related to the base stations of FIGS. 2-8 herein.

As an example, the processor 1060 generates one DCI for power control of two PUCCHs (PCells) and a PUCCH (SCell), scrambles the PDCCH including the generated DCIs with a TPC-PUCCH RNTI, and scrambles The PDCCH is mapped to the CSS of the main serving cell.

As another example, the processor 1060 generates a first DCI for power control of the PUCCH (PCell), and generates a second DCI for power control of the PUCCH (SCell). At this time, the processor 1060 includes a CIF indicating the primary serving cell in the second DCI. The processor 1060 scrambles PDCCH1 including the first DCI with the TPC-PUCCH RNTI, and scrambles PDCCH2 including the second DCI with the TPC-PUCCH RNTI. The processor 1060 maps the scrambled PDCCH1 and PDCCH2 to the CSS of the main serving cell.

As another example, the processor 1060 generates a first DCI for power control of the PUCCH (PCell), and generates a second DCI for power control of the PUCCH (SCell). The processor 1060 scrambles PDCCH1 including the first DCI with the TPC-PUCCH RNTI, and scrambles PDCCH2 including the second DCI with the TPC-PUCCH-SCell RNTI. The processor 1060 maps the scrambled PDCCH1 and PDCCH2 to the CSS of the main serving cell.

As another example, the processor 1060 maps the PDCCH1 scrambled with the TPC-PUCCH RNTI to the CSS on the main serving cell, and the PDCCH2 scrambled with the TPC-PUCCH RNTI to the CSS on the secondary serving cell. This is a case where the RF unit 1060 receives performance information indicating that the MBMS can be supported from the terminal 1000.

The above-described processor may include an application-specific integrated circuit (ASIC), another chipset, a logic circuit and / or a data processing device. The memory may include read-only memory (ROM), random access memory (RAM), flash memory, memory card, storage medium and / or other storage device. The RF unit may include a baseband circuit for processing a radio signal. When the present embodiment is implemented in software, the above-described technique may be implemented as a module (process, function, etc.) for performing the above-described function. The module may be stored in memory and executed by a processor. The memory may be internal or external to the processor and may be coupled to the processor by various well known means.

Claims

A power control method by a terminal supporting carrier aggregation based on a plurality of serving cells,

A first transmission power control (TPC) index for an uplink control channel (hereinafter referred to as PUCCH (PCell)) on a primary serving cell (PCell) and a secondary serving cell (SCell) Receiving an upper layer message from a base station including a second TPC index on an uplink control channel (hereinafter, referred to as PUCCH (SCell)) on a base station;

Receiving a first TPC command corresponding to the first TPC index and a second TPC command corresponding to the second TPC index from the base station; And

Controlling the power of the PUCCH (PCell) based on the first TPC command, and controlling the power of the PUCCH (SCell) based on the second TPC command.
The method of claim 1,

Wherein the first TPC command and the second TPC command are included in one downlink control information (DCI) and received from the base station.
The method of claim 2,

And the DCI is mapped and received on a common search space on the main serving cell.
The method of claim 1,

Wherein the first TPC command is included in a first DCI and received from the base station, and the second TPC command is included in a second DCI and received from the base station.
The method of claim 4, wherein

And the first DCI and the second DCI are mapped and received on a common search space on the main serving cell.
The method of claim 5, wherein

The PDCCH for the first DCI and the PDCCH for the second DCI are scrambled by the same radio network temporary indentifier (RNTI),

The second DCI comprises a carrier indicator field (CIF) indicating the secondary serving cell, power control method.
The method of claim 5, wherein

And the PDCCH for the first DCI and the PDCCH for the second DCI are scrambled by different identical RNTIs.
The method of claim 4, wherein

The first DCI is received mapped on the common search space on the main serving cell,

And the second DCI is mapped and received on a common search space on the secondary serving cell.
A power control apparatus supporting carrier aggregation based on a plurality of serving cells,

An RF unit for receiving an upper layer message and a TPC command message from a base station;

A first transmission power control (TPC) index for an uplink control channel (hereinafter referred to as PUCCH (PCell)) on a primary serving cell (PCell) from the received message, and a secondary serving cell serving cell: identifying a second TPC index on an uplink control channel (hereinafter, referred to as a PUCCH (SCell)) on a SCell, and a first TPC command corresponding to the first TPC index and a second TPC index corresponding to the second TPC index. A power control including a processor that checks a 2 TPC command, controls power of the PUCCH (PCell) based on the first TPC command, and controls power of the PUCCH (SCell) based on the second TPC command Device.
The processor of claim 9, wherein the processor comprises:

And controlling power by checking one downlink control information (DCI) including the first TPC command and the second TPC command.
The processor of claim 9, wherein the processor comprises:

And receiving and confirming the DCI mapped on the common search space on the main serving cell.
The processor of claim 9, wherein the processor comprises:

And receiving and confirming the first TPC command included in a first DCI from the base station, and confirming and receiving the second TPC command included in a second DCI from the base station.
The processor of claim 9, wherein the processor comprises:

And receiving and confirming the first DCI and the second DCI mapped to the common search space on the main serving cell.
The processor of claim 9, wherein the processor comprises:

The PDCCH for the first DCI and the PDCCH for the second DCI are scrambled by the same radio network temporary indentifier (RNTI),

And confirming that the second DCI includes a carrier indicator field (CIF) indicating the secondary serving cell.
The processor of claim 9, wherein the processor comprises:

And determining that the PDCCH for the first DCI and the PDCCH for the second DCI are scrambled by different identical RNTIs.
The processor of claim 9, wherein the processor comprises:

Identify the first DCI mapped on the common search space on the primary serving cell

And identifying the second DCI mapped on the common search space on the secondary serving cell.