KR20120121787A - Apparatus And Method For Controling Transmission Power Of Reference SignalIn a Communication System - Google Patents

Abstract

PURPOSE: A reference signal transmission power control apparatus in a communication system and method thereof are provided to effectively control transmission power by allocating the transmission power of an uplink reference signal from residual power. CONSTITUTION: When a PUCCH(Physical Uplink Control Channel) is requested to a sub-frame, the PUCCH transmission power is allocated to the sub-frame(S402,S403). When a PUSCH(Physical Uplink Shared Channel) is requested to the sub-frame, the PUSCH transmission power is allocated to the sub-frame(S405,S406). SRS(Sounding Reference Signal) transmission power is allocated to the sub-frame(S408). When the SRS transmission power is more than a predetermined threshold value, a terminal transmits an SRS using the calculated transmission power(S409,S410). [Reference numerals] (AA) Start; (BB,DD,FF) No; (CC,EE,GG) Yes; (HH) End; (S402) PUCCH transmission?; (S403) PUCCH transmission power allocation; (S405) PUSCH transmission?; (S406) PUSCH transmission power allocation; (S408) SRS transmission power allocation; (S410) SRS transmission; (S411) SRS transmission cancelation

Description

Apparatus And Method For Controling Transmission Power Of Reference Signal In a Communication System}

The present invention relates to a communication system, and more particularly, to an apparatus and method for controlling reference signal transmission power in a communication system.

In a communication system, each terminal controls power of a physical channel and a signal such that different uplink physical channels and signals are received at a base station (cell).

Uplink power control is a closed loop scheme in which the transmit power of the terminal varies depending on the downlink path loss, and additionally, a direct control of the transmit power of the terminal through an explicit power control command transmitted through the downlink. There is a loop method.

Uplink power is limited by the power that the terminal can output at maximum. The terminal controls the power of the physical channel and the signal within the limited available power.

An object of the present invention is to provide a method for allocating transmission power of a plurality of uplink physical channels and uplink reference signals simultaneously.

In order to achieve the above object, an embodiment of the present invention provides a method for controlling reference signal transmission power in a communication system, the method comprising: calculating transmission power of an uplink control channel and an uplink data channel transmitted simultaneously with an uplink reference signal; ; And calculating a transmission power of an uplink reference signal, wherein an upper limit of the transmission power of the uplink reference signal is simultaneously transmitted with the uplink reference signal at the maximum transmission power in a plurality of cells. And a power remaining after the transmission power of the uplink data channel is allocated.

Another embodiment of the present invention, a transmission power calculation unit for calculating the transmission power of the uplink control channel, uplink data channel and uplink reference signal; And a transmission power control unit controlling uplink transmission power by the transmission power calculated by the transmission power calculating unit, wherein an upper limit of the transmission power of an uplink reference signal is the maximum reference power at the maximum transmission power in a plurality of cells. And the transmit power of the uplink control channel and the uplink data channel transmitted simultaneously with the remaining power.

According to the present invention described above, since the transmit power is first assigned to an uplink physical channel such as an uplink control channel and an uplink data channel, the transmit power of the uplink reference signal is allocated from the remaining power to efficiently control the transmit power. can do. In addition, transmit power may be efficiently allocated when uplink reference signals are simultaneously transmitted in a plurality of CCs.

1 is a diagram illustrating an example of a communication system to which embodiments of the present invention can be applied;
2 is a diagram illustrating an example of a case in which a PUCCH, a PUSCH, and a CRS may be allocated in one serving cell;
3 is a diagram illustrating an example where a plurality of PUCCHs and PUSCHs are simultaneously transmitted in a plurality of serving cells;
4 is a flowchart of a SRS transmission power control method according to an embodiment of the present invention;
5 is a diagram illustrating an example to which the SRS transmission power control method of FIG. 4 may be applied;
6 is a diagram illustrating an example of a case where a plurality of SRSs are simultaneously transmitted in a plurality of serving cells;
7 is a diagram illustrating another example when a plurality of SRSs are simultaneously transmitted in a plurality of serving cells; and
8 is a block diagram of a terminal device according to an embodiment of the present invention.

Hereinafter, some embodiments of the present invention will be described in detail with reference to exemplary 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 the following description of the present invention, a detailed description of known functions and configurations incorporated herein will be omitted when it may make the subject matter of the present invention rather unclear.

1 illustrates a communication system to which embodiments of the present invention are applied.

Communication systems are widely deployed to provide various communication services such as voice, packet data, and the like.

Referring to FIG. 1, a communication system includes a user equipment (UE) 10 and a base station 20 (BS).

In the present specification, the terminal 10 or a user equipment (UE) is a comprehensive concept that means a user terminal in wireless communication. In addition to the UE in WCDMA, LTE, and HSPA, as well as MS (Mobile Station) and UT (GSM) in GSM, It should be interpreted as a concept that includes a user terminal, a subscriber station (SS), and a wireless device.

A base station 20 or a cell generally refers to a station communicating with the terminal 10, and includes a Node-B, an evolved Node-B, an eNB, a Base Transceiver System (BTS), It may be called other terms such as an access point and a relay node.

In the present specification, the base station 20 or a cell is to be interpreted in a comprehensive sense indicating some areas covered by a base station controller (BSC) in a CDMA, a NodeB of a WCDMA, and the like, and a radio remote head connected to the base station ) A comprehensive concept of any type of device capable of communicating with one terminal, such as a relay node, a sector of a macro cell, a site, or a micro cell such as a femtocell or picocell. Used as

In the present specification, the terminal 10 and the base station 20 are used in a generic sense as a transmitting and receiving entity used to implement the technology or technical idea described in the present specification and are not limited to the terms or words specifically referred to.

There are no limitations to the multiple access scheme applied to a communication system, and the present invention provides the code division multiple access (CDMA), time division multiple access (TDMA), frequency division multiple access (FDMA), orthogonal frequency division multiple access (OFDMA), and OFDM. Applicable to various multiple access schemes such as FDMA, OFDM-TDMA, and OFDM-CDMA.

In addition, the present invention is a combination of the TDD (Time Division Duplex) method is transmitted using a different time, uplink transmission and downlink transmission, FDD (Frequency Division Duplex) method is transmitted using a different frequency, combining the TDD and FDD Applicable to hybrid duplexing method.

Specifically, embodiments of the present invention are applicable to asynchronous wireless communication that evolves into Long Term Evolution (LTE) and LTE-advanced through GSM, WCDMA, HSPA, and synchronous wireless communication that evolves into CDMA, CDMA-2000, and UMB. Can be. The present invention should not be construed as being limited or limited to a specific wireless communication field, but should be interpreted as including all technical fields to which the spirit of the present invention can be applied.

Referring back to FIG. 1, the terminal 10 and the base station 20 may communicate in uplink and downlink.

The base station 20 performs downlink transmission to the terminal 10. The base station 20 is a downlink control information and uplink data channel such as a physical downlink shared channel (PDSCH), which is a main physical channel for unicast transmission, and scheduling required for reception of the PDSCH. A physical downlink control channel (PDCCH) for transmitting scheduling grant information for transmission in (eg, a physical uplink shared channel (PUSCH)) may be transmitted. Hereinafter, the transmission and reception of signals through each channel will be described in the form of transmission and reception of the corresponding channel.

The terminal 10 transmits an uplink signal to the base station 20. The terminal 10 includes a PUSCH, which is a main physical channel for unicast transmission, as an uplink data channel, and HARQ acknowledgment, channel status report, and uplink indicating whether a downlink transport block is successfully received as an uplink control channel. When transmitting data and transmitting a physical uplink control channel (PUCCH), which is a channel used for transmitting uplink control information (UCI) including a scheduling request for requesting resource allocation. Can be.

On the other hand, one radioframe or radio frame is composed of 10 subframes, and one subframe is composed of two slots. The radio frame has a length of 10 ms and the subframe has a length of 1.0 ms. In general, a basic unit of data transmission is a subframe unit, and downlink or uplink scheduling is performed in units of subframes.

One slot may have a plurality of OFDM symbols in the time domain and include at least one subcarrier in the frequency domain. For example, a slot may include seven OFDM symbols (in the case of the Normal Cyclic Prefix) or six OFDM symbols in the time domain and may include 12 subcarriers in the frequency domain. The time-frequency domain defined as one slot may be referred to as a resource block (RB), but is not limited thereto.

The uplink resource block to which the PUCCH is allocated is located at the edge of the total available cell bandwidth. This is for the purpose of maximizing the frequency diversity experienced by the control signaling, and for the purpose of allocating a wide transmission bandwidth to a single terminal while maintaining the single carrier characteristic of the uplink transmission by not splitting the uplink spectrum. The PUSCH is mapped between the edges to which the PUCCH is mapped, and the amount of contiguous spectrum possible for PUSCH transmission is maximized.

The base station 20 includes a cell-specific reference signal (CRS), a MBSFN reference signal (Multicast / Broadcast over Single Frequency Network Reference Signal, MBSFN-RS), and a UE-specific reference signal (UE-) in downlink. Specific Reference Signal (DM-RS), Positioning Reference Signal (PRS), and CSI Reference Signal (CSI Reference Signal, CSI-RS) may be transmitted.

The terminal 10 may transmit a demodulation reference signal (DRS) and a sounding reference signal (SRS) in uplink.

Among these, the SRSs are mutually provided at regular intervals so as to transmit the uplink channel information for the entire band including not only a band to be used by each terminal 10 but also a band that the terminal 10 may use. Allows transmission on other bands that do not overlap or transmission across the entire sub-carrier band through one or more transmissions.

The uplink reference signal may be transmitted in the last symbol of each subframe. For example, when one subframe consists of 14 symbols (Normal Cyclic Prefix), the uplink reference signal is transmitted in the 14th symbol, and when 12 symbols (Extended Cyclic Prefix) is used, the SRS It is transmitted in the 12th symbol.

According to the current LTE standard, the SRS sequence is generated by Equation 1 below, and the generated SRS sequence is transmitted according to the subframe configuration as shown in Table 1 after the resource mapping according to a predetermined criterion.

[Equation 1]

,

,

는 기준신호 시퀀스의 길이이고,

이고, u는 PUCCH 시퀀스 그룹번호이고, v는 베이스 시퀀스 번호이며, 싸이클릭 시프트(Cyclic Shift; CS)

이다.

는 0 내지 7 중 하나의 정수 값으로서 상위 계층에 의하여 각 UE마다 설정된다. here,

Is the length of the reference signal sequence,

U is a PUCCH sequence group number, v is a base sequence number, and a cyclic shift (CS)

to be.

Is an integer value of one of 0 to 7, and is set for each UE by a higher layer.

[Table 1]

Table 1 above is a subframe configuration table of the FDD sounding reference signal defined in LTE. Each format (srsSubframeConfiguration) is defined as 4 bits, and the transmission period and the offset of the transmission subframe of the sounding reference signal of the UE in the cell. It is prescribed.

That is, for example, when the srsSubframeConfiguration value is 8 (1000 in binary), it means that terminals in a cell can transmit SRS in second and third subframes every five subframes.

[Table 2]

Table 2 above shows the configuration of the SRSConfigurationIndex parameter (I _SRS ) indicated independently to each terminal. Each terminal is instructed to the actual SRS transmission through the 10-bit parameter. For example, when SRSConfigurationIndex (I _SRS ) is 40, SRS transmission is transmitted in the third subframe (I _SRS- 37) every 40 subframes.

As described above, the SRS transmitted according to the offset and the transmission period is referred to as periodic SRS (Periodic SRS).

SRS may be transmitted aperiodically for efficient transmission of various SRSs. This is to increase the efficiency of the transmission by efficiently using the limited SRS resources by allowing the terminal with a large amount of data to transmit aperiodic SRS. The base station 20 may transmit a signal indicating to transmit aperiodic SRS to the terminal 10, that is, SRS triggering. Such triggering may be delivered through a DCI format. Upon receiving the SRS triggering, the terminal 10 transmits the SRS at a frequency and a time previously scheduled with the base station 10.

Hereinafter, power control of the terminal 10 in uplink will be described.

2 illustrates an example in which a PUSCH, a PUCCH, and an SRS are allocated in a cell. In FIG. 2, horizontal is a subframe and vertical is a band of a cell.

2 (a) shows that only a PUSCH is mapped in a cell. Referring to FIG. 2A, the PUSCH is transmitted in the center excluding the edge of the bandwidth in the cell.

2 (b) shows that a PUSCH and a PUCCH are simultaneously mapped in a cell. Referring to FIG. 2 (b), the PUCCH is transmitted at the edge of the bandwidth in the cell, and the PUSCH is transmitted at the center of the bandwidth.

2 (c) shows that the SRS is mapped in the cell. Referring to FIG. 2C, the SRS is transmitted in the last symbol of the subframe.

)은 다음의 수학식 2와 같다.As shown in FIG. 2 (a), when the UE 10 transmits a PUSCH in a serving cell c, the transmit power of the PUSCH in the subframe i for the serving cell c may be

) Is shown in Equation 2 below.

&Quot; (2) "

[dBm]

[dBm]

)은 다음의 수학식 3과 같다.As shown in FIG. 2 (b), when the UE 10 transmits a PUSCH with a PUCCH in a serving cell c, the transmit power of the PUSCH in a subframe i for the serving cell c (

) Is as shown in Equation 3 below.

&Quot; (3) "

[dBm]

[dBm]

는 P_{CMAX ,c}(i)의 선형 값(linear value)이다.

는 PUCCH의 전송 전력인 P_PUCCH(i)의 선형 값으로서, 이에 대하여는 후술될 것이다. 수학식 2를 참조하면, PUSCH를 PUCCH와 동시에 전송하지 않는 경우, PUSCH 전송 전력은 단말(10)의 서빙 셀(c)에서 최대 전송 전력에 의해 제한된다. 수학식 3을 참조하면, PUSCH를 PUCCH와 동시에 전송하는 경우, PUSCH 전송 전력은 단말(10)의 최대 전송 전력에서 PUCCH의 전송 전력을 제한 값에 의해 제한된다.In Equations 2 and 3, P _{CMAX , c} (i) is the maximum transmit power of the terminal 10 in the subframe (i) for the serving cell (c),

Is the linear value of P _{CMAX , c} (i).

Is a linear value of P _PUCCH (i) which is a transmission power of _PUCCH , which will be described later. Referring to Equation 2, when the PUSCH is not transmitted simultaneously with the PUCCH, the PUSCH transmission power is limited by the maximum transmission power in the serving cell (c) of the terminal 10. Referring to Equation 3, when the PUSCH is simultaneously transmitted with the PUCCH, the PUSCH transmit power is limited by the limit value of the transmit power of the PUCCH at the maximum transmit power of the terminal 10.

M _{PUSCH, c} (i) is the bandwidth of the PUSCH resource allocation expressed as the number of valid resource blocks for the serving cell (c) and subframe (i). Allocation of more resource blocks requires higher transmit power.

)과 단말-특정 전력 레벨(

)로 구성된다.(

=

+

).P _{0 _ PUSCH , c} (j) is a semi-static base level, the common power level (

) And terminal-specific power level (

It consists of

=

+

).

In other words, P _{0_PUSCH, c} (j) is a factor for the received power that should be guaranteed in transmitting the PUSCH. P _{0_PUSCH} means the reception power required to obtain a reception signal-to-interference and noise ratio (SINR) required by the base station. P _{0_PUSCH} is a value determined based on the interference level at the base station, and the interference may vary depending on the system construction situation and may vary depending on time since the load in the network changes over time.

J = 0 for PUSCH (re) transmission for semi-persistent grant, j = 1 for PUSCH (re) transmission for dynamic scheduled grant, random J = 2 for PUSCH (re) transmission for random access response grant.

α _c (j) represents the extent to which the path loss is compensated. If α _c (j) is 1, path loss is completely compensated, and if α _c (j) is less than 1, path loss is not completely compensated. α _c (j) α {0, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 1} when j = 0 or 1, and α _c (j) = 1 when j = 2.

PL _c is a downlink path loss estimated value calculated by the terminal 10 with respect to the serving cell c, and PL _c = (Reference Signal Received Power (RSRP) Can be determined by the following equation.

Δ _{TF, c} (i) is an offset determined by the Modulation and Coding Scheme (MCS) for the serving cell (c).

f _c (i) is a value for directly adjusting the PUSCH transmit power through an explicit power control command. f (i) is a cumulative value, increasing or decreasing by a certain amount. f (i) is in UL grant.

의 식으로표현될 수 있다.

는 서브프레임

에서 DCI 포맷 0 또는 3/3A로 PDCCH로 신호될 수 있다. 누적이 가능하지 않을 때

이다.More specifically,

It can be expressed as

Is a subframe

In DCI format 0 or 3 / 3A can be signaled to the PDCCH. When accumulation is not possible

to be.

)은 다음의 수학식 4와 같다.If the serving cell (c) is a primary cell, the transmit power of the PUCCH in subframe (i)

) Is as shown in Equation 4 below.

&Quot; (4) "

[dBm]

[dBm]

In Equation 4, P _{CMAX, c} (i) is the maximum transmit power of the terminal 10 in the subframe (i) with respect to the serving cell (c), PUCCH transmit power is limited thereto.

)과 단말-특정 전력 레벨(

)로 구성된다.P _{0 _ PUCCH} is the common power level (

) And terminal-specific power level (

).

In other words, P _{0_PUCCH} is a factor for the received power that must be guaranteed in transmitting the PUCCH. P _{0_PUCCH} is a factor for the received power required to obtain the received SINR required by the base station, and is determined by the PUCCH format and the like.

PL _c is a downlink path loss estimated value calculated by the terminal 10 with respect to the serving cell c, and PL _c = (Reference Signal Received Power (RSRP) Is determined by

h (n _CQI , n _HARQ, n _SR ) is n _CQI corresponding to the number of information bits for Channel Quality Information ( _CQI ), n _HARQ , the number of HARQ bits transmitted in subframe (i), and subframe (i ) Is a power offset by n _SR indicating whether a scheduling request (SR) is configured for the UE.

이다.About PUCCH Formats 1, 1a, and 1b

to be.

이고, 다른 경우

이다.For PUCCH format 1b with channel selection, the terminal is composed of one or more serving cells

, Otherwise

to be.

이다.If PUCCH formats 2, 2a, 2b and normal cyclic prefix,

to be.

이다.If PUCCH format 2 and extended cyclic prefix,

to be.

이다.For PUCCH format 3, when the terminal is configured by a higher layer to transmit the PUCCH to two antenna ports, or when the terminal transmits more than 11 bits of HARQ-ACK,

to be.

이다.For PUCCH format 3, if different

to be.

Δ _{F_PUCCH} (F) is an offset determined by the PUCCH format (F).

Δ _TxD (F ′) is an offset considering the case where the terminal 10 is configured to transmit PUCCH in two antenna ports.

g (i) is a value for directly adjusting the PUCCH transmit power through an explicit power control command. g (i) is cumulative and increases or decreases by a certain amount. g (i) may be included in the downlink scheduling assignment (DCI format 1A / 1B / 1D / 1 / 2A / 2 / 2B) or may be provided on a special PDCCH that simultaneously provides power control commands to multiple terminals. (DCI format 3 / 3A). g (i) may be used to compensate for uplink multipath fading not reflected in downlink path loss, and to compensate for a change in uplink interference not reflected in P _{0_PUCCH} .

의 식으로 표현될수 있다. g(i)는 현재 PUCCH 전력 제어 조절 상태이고, g(0)는 리셋 후 초기값이다. More specifically,

It can be expressed as g (i) is the current PUCCH power control adjustment state, and g (0) is the initial value after reset.

)은 다음의 수학식 5와 같이 규정된다.UE transmit power of SRS transmitted in subframe (i) for serving cell (c)

) Is defined as in Equation 5 below.

[Equation 5]

[dBm]

[dBm]

In Equation 5, P _{CMAX, c} (i) is the maximum transmit power of the terminal 10 in the subframe (i) for the serving cell (c), the SRS transmit power is limited thereto.

는 오프셋값으로서 서빙 셀(c)에서 m=0 그리고 m=1에 대해 상위 계층에 의해 규정되는 반-정적 4-비트 인자이다. 트리거 타입(trigger type) 0으로 주어진 SRS 전송일 때 m=0이고, 트리거 타입 1로 주어진 SRS 전송일 때 m=1이다. Ks=1.25일 때,

는 [-3,12]dB 범위에서 1 dB 간격의 크기를 갖는다. Ks=0일 때,

는 [-10.5,12]dB 범위에서 1.5 dB 간격의 크기를 갖는다.

Is a semi-static 4-bit factor defined by the upper layer for m = 0 and m = 1 in the serving cell c as the offset value. M = 0 for an SRS transmission given a trigger type 0, and m = 1 for an SRS transmission given a trigger type 1. When Ks = 1.25,

Has a size of 1 dB in the [-3,12] dB range. When Ks = 0,

Has a size of 1.5 dB in the range [-10.5,12] dB.

M _{SRS, c} is the bandwidth of the SRS transmission in the subframe (i) for the serving cell (c) expressed by the number of resource blocks.

f _c (i) is as defined in equations (2) and (3).

P _{0_PUSCH, c} (j) and α _c (j) are as defined in equations (2) and (3), and j = 1.

Meanwhile, the LTE / LTE-A system defines the use of a component carrier (CC), which is a plurality of unit carriers, as a method for extending a system requirement, that is, a bandwidth for satisfying a high data rate. Here, one CC may have a bandwidth of up to 20 MHz, and resources can be allocated within 20 MHz according to a corresponding service, but this is only one embodiment according to a process of implementing a system and a bandwidth of 20 MHz or more depending on the implementation of a system. Can be set to have. In addition, it is possible to define the use of a carrier aggregation (CA) technology that bundles a plurality of component carriers to use a single system band.

As an example, when five element carriers having a maximum bandwidth of 20 MHz are used, the bandwidth can be extended up to 100 MHz to support quality of service. The assignable frequency band that can be determined by the component carriers may be contiguous or non-contiguous depending on the scheduling of the actual CA.

In a CA environment, in order to efficiently manage a plurality of CCs, a plurality of CCs may be divided into one Primary Component Carrier (PCC) and one or more Secondary Component Carriers (SCC). Alternatively, the primary carrier (PCC) may be called a primary cell, and the secondary component carrier (SCC) may be called a secondary cell.

The PCC may serve as a core carrier for managing the aggregated CCs, and the remaining SCs may serve as additional frequency resources for providing more data rates. . For example, the PUCCH and PUSCH including the UCI for the control of the uplink in the uplink can be transmitted only through the major carrier (PCC), the PUCCH and PUSCH including the UCI is transmitted through the sub-component carrier (SCC) It may not be.

Alternatively, in order to efficiently manage a plurality of component carriers, an index (serving cell index) (ServCellIndex) may be assigned to the plurality of component carriers. For example, when five component carriers CC0, CC1, CC2, CC3, and CC4 are integrated, a serving cell index (ServCellIndex) of each component carrier may be specified as 0 to 4. For example, in the above example, CC0 having a serving cell index of 0 may be a major carrier (PCC), and CC1 to CC4 having a serving cell index of 1 to 4 may be a subcomponent carrier (SCC).

3 illustrates a case where PUCCH and / or PUSCH are transmitted in a plurality of component carriers and a single subframe. Although two component carriers CC0 and CC1 are shown in FIG. 3, a plurality of component carriers may exist as an example. In the example of FIG. 3, the first CC CC0 is a major carrier PCC and the second CC CC1 is a subcomponent carrier SCC.

In FIG. 3, (a) illustrates a case where a PUCCH is transmitted on a first component carrier CC0 and a PUSCH is transmitted on a second component carrier CC1.

PUCCH includes uplink control information and thus has higher importance than PUSCH. Therefore, the power of the terminal is preferentially allocated to the transmit power of the PUCCH, and among the remaining powers, the transmit power of the PUSCH is allocated. The transmit power of the PUSCH satisfies Equation 6 below.

&Quot; (6) "

는 수학식 4에서 규정된 PUSCH 전송 전력의 선형값이고,

는 수학식 2 또는 3에서 규정된 PDSCH 전송 전력의 선형값이다. In Equation (6)

Is a linear value of the PUSCH transmit power defined in Equation 4,

Is a linear value of the PDSCH transmit power defined in Equation (2) or (3).

는 단말이 다수의 셀 전체에서 최대 전송 전력

의 선형값이다.

The maximum transmission power of the terminal in the entire number of cells

Is a linear value of.

W (i) is a scaling factor and has a range of 0 ≦ w (i) ≦ 1.

Equation 6 indicates that PUCCH transmit power is allocated first in the total transmit power for a plurality of cells, and PUSCH transmit power is allocated in the remaining power. If the remaining power after allocating the PUCCH transmit power is sufficient, the value defined in Equation 2 or 3 will be allocated as the PUSCH transmit power ( w (i) = 1). However, if it is not sufficient, the actual PUSCH transmit power will be assigned a reduced value by multiplying the value defined in Equation 2 or 3 by the scaling factor w (i) ( w (i) <1).

In FIG. 3, (b) illustrates a case where a PUSCH having uplink control information UCI is transmitted on a first component carrier CC0 and a PUSCH having no UCI is transmitted on a second component carrier CC1.

PUSCH with UCI has higher importance than PUSCH without UCI. Therefore, the power of the terminal is preferentially allocated to the PUSCH having the UCI, and the transmission power of the PUSCH having no UCI among the remaining powers is allocated. The transmit power of a PUSCH without UCI satisfies Equation 7 below.

[Equation 7]

는 수학식 2 또는 3에 의해 계산되는 UCI를 갖는 PUSCH의 전송 전력의 선형값이고,

는 수학식 2 또는 3에 의해 계산되는 UCI를 갖지 않는 PUSCH의 전송 전력의 선형값이다.In Equation 7, j is an index of a serving cell transmitting a PUSCH having UCI, and c (c ≠ j) except for a j value is an index of a serving cell transmitting a PUSCH having no UCI. In other words,

Is a linear value of the transmit power of the PUSCH having the UCI calculated by Equation 2 or 3,

Is a linear value of the transmit power of the PUSCH without the UCI calculated by Equation 2 or 3.

는 단말이 다수의 셀 전체에서 최대 전송 전력

의 선형값이다.

The maximum transmission power of the terminal in the entire number of cells

Is a linear value of.

W (i) is a scaling factor and has a range of 0 ≦ w (i) ≦ 1.

Equation (7) indicates that a PUSCH transmission power with UCI is allocated first in total transmission power for a plurality of cells, and a PUSCH transmission power without UCI is allocated in remaining power. If the remaining power after allocating the PUSCH transmission power with the UCI is sufficient, the value defined in Equation 2 or 3 will be allocated to the PUSCH transmission power without the UCI ( w (i) = 1). However, if it is not sufficient, the PUSCH transmission power having no actual UCI will be assigned a reduced value by multiplying the value defined in Equation 2 or 3 by the scaling factor w (i) ( w (i) <1 ).

In FIG. 3, (c) illustrates a case where a PUSCH having a PUCCH and a UCI are simultaneously transmitted on a first component carrier CC0 and a PUSCH having no UCI is transmitted on a second component carrier CC1.

In this case, the PUCCH has a higher importance than the PUSCH, and among the PUSCHs, a PUSCH having a UCI has a higher importance than a PUSCH having no UCI. Therefore, the power of the UE will be allocated in the order of PUCCH, PUSCH with UCI, and PUSCH without UCI.

The transmit power of the PUCCH is calculated by Equation 4.

The transmit power of the PUSCH with UCI satisfies Equation 8 below.

[Equation 8]

In Equation 8, the first and second rows represent Equation 3 as a linear value.

는 단말이 다수의 셀 전체에서 최대 전송 전력

의 선형값이고,

는 수학식 4에서 규정된 PUCCH 전송 전력의 선형값이다.In the third row

The maximum transmission power of the terminal in the entire number of cells

Is a linear value of

Is a linear value of the PUCCH transmit power defined in Equation 4.

)은 서빙 셀(j)에 대한 최대 전송 전력(

)보다 크거나 같을 것이기 때문에, 수학식 8의 결과는 수학식 3의 결과와 같을 수 있다.Equation 8 shows that PUCCH transmit power is allocated first in the total transmit power for a plurality of cells, and transmit power of a PUSCH having UCI is allocated at the remaining power. On the other hand, the total transmit power for multiple cells (

Is the maximum transmit power () for the serving cell (j)

Since it will be greater than or equal to), the result of Equation 8 may be the same as the result of Equation 3.

And, the transmit power of the PUSCH without UCI satisfies the following equation (9).

&Quot; (9) &quot;

는 단말이 다수의 셀 전체에서 최대 전송 전력

의 선형값이고,

는 수학식 4에서 규정된 PUCCH 전송 전력의 선형값이며,

는 수학식 8에서 규정된 UCI를 갖는 PUSCH 전송 전력의 선형값이고,

는 수학식 2에서 규정된 UCI를 갖는 않는 PUSCH 전송 전력의 선형값이다.In Equation 9,

The maximum transmission power of the terminal in the entire number of cells

Is a linear value of

Is a linear value of the PUCCH transmit power defined in Equation 4,

Is a linear value of the PUSCH transmit power with UCI defined in Equation 8,

Is a linear value of the PUSCH transmit power without the UCI defined in equation (2).

W (i) is a scaling factor and has a range of 0 ≦ w (i) ≦ 1.

Equation 9 shows that PUSCH transmission power with PUCCH transmission power and UCI is allocated first in total transmission power for a plurality of cells, and PUSCH transmission power without UCI is allocated with remaining power. If the power remaining after allocating the PUSCH transmission power with the UCI is sufficient, the value defined in Equation 2 will be allocated to the PUSCH transmission power without the UCI ( w (i) = 1). However, if it is not sufficient, the PUSCH transmission power without the actual UCI will be assigned a reduced value by multiplying the value defined in Equation 2 by the scaling factor w (i) ( w (i) <1).

Next, consider a case in which SRSs are transmitted simultaneously with PUCCH, PUSCH and / or other SRSs in a plurality of CCs and a single subframe.

The priority of power allocation may be in the order of PUCCH, PUSCH, SRS. PUCCH is for uplink control and may have the highest priority. PUSCH may have priority after PUCCH. Among the PUSCHs, a PUSCH having a UCI may have priority over a PUSCH having no UCI. SRS is used for scheduling resource blocks in uplink afterwards and has a lower priority than PUCCH and PUSCH. This is summarized in Table 2 below.

TABLE 2

4 is a flowchart illustrating a method of determining SRS transmit power according to an embodiment of the present invention.

FIG. 5 is an example to which the method of FIG. 4 is applied, and a PUCCH 501 is transmitted on a first component carrier CC0, a PUSCH 502 is transmitted on a second component carrier CC1, and a third component carrier CC2. In this case, the SRS 503 is transmitted.

)의 초기값은 다수의 셀에 대한 전체 전송 전력(

)의 선형값(

)이다(S401 단계). Referring to FIG. 4, the linear value of the available power P available to the UE for uplink transmission (

The initial value of) is the total transmit power for multiple cells (

Linear value of

(Step S401).

)은 이전의 가용 전력의 선형값(

)에서 PUCCH 전송 전력의 선형값(

)이 감해진 값으로 갱신된다(S404 단계).When PUCCH 501 transmission is required in subframe i (YES in step S402), PUCCH transmission power is allocated first (step S403). PUCCH transmit power is calculated by equation (4). And, the linear value of the available power (

) Is the linear value of the previous available power (

Linear value of the PUCCH transmit power at

) Is updated to the reduced value (step S404).

)은 PUCCH 전송 전력의 선형값(

)이 감해지지 않은 값으로 유지된다.If PUCCH transmission is not required in subframe (i) (NO in step S402), the linear value of the available power (

) Is the linear value of the PUCCH transmit power (

) Remains undecreased.

If the PUSCH 502 transmission is required in the subframe (i) (YES in step S405), the PUSCH transmission power is allocated next (step S406).

The transmit power of the PUSCH with UCI is calculated by equation (2) or equation (8). That is, when PUCCH transmit power is not allocated, the transmit power of the PUSCH having UCI is calculated by Equation 2, and when PUCCH transmit power is allocated, the transmit power of the PUSCH having UCI is calculated by Equation 8.

The transmit power of the PUSCH without UCI may be calculated by Equation 2 or 3 and may be limited by the condition of Equation 6, 7 or 9. That is, when a PUSCH is not transmitted simultaneously with a PUCCH in one cell, the transmit power of the PUSCH without UCI is calculated by Equation 2, and when the PUSCH is transmitted simultaneously with the PUCCH, the transmit power of the PUSCH without UCI is expressed by Equation 2. Calculated by equation 3. When PUCCH is transmitted in another cell, the transmit power of the PUSCH without UCI is limited by Equation 6, and when the PUSCH having UCI is transmitted in another cell, the transmit power of the PUSCH without UCI is expressed by Equation 7 When the PUSCH having the PUCCH and the UCI is transmitted in another cell, the transmission power of the PUSCH having no UCI is limited by Equation 9.

)은 PUSCH 전송 전력의 선형값(

)이 감해진 값으로 갱신된다(S407 단계). 다수개의 PUSCH가 전송되는 경우, 가용 전력의 선형값(

)은 PUSCH 전송 전력의 선형값의 합(

)이 감해진 값으로 갱신된다.And, the linear value of the available power (

) Is the linear value of the PUSCH transmit power (

) Is updated to the reduced value (step S407). When multiple PUSCHs are transmitted, the linear value of the available power (

) Is the sum of the linear values of the PUSCH transmit power (

) Is updated with the subtracted value.

)은 PUSCH 전송 전력의 선형값(

)이 감해지지 않은 값으로 유지된다.On the other hand, if the PUSCH transmission is not required in the subframe (i) (NO in step S405), the linear value of the available power (

) Is the linear value of the PUSCH transmit power (

) Remains undecreased.

)은 초기값(

)에서 PUCCH 전송 전력의 선형값 및 PUSCH 전송 전력의 선형값이 감해진 값이고, (2) PUCCH의 전송이 요구되고 PUSCH의 전송이 요구되지 않는 경우(S402 단계에서 예, S405 단계에서 아니오), 가용 전력의 선형값(

)은 초기값(

)에서 PUCCH 전송 전력의 선형값이 감해진 값이며, (3) PUCCH의 전송이 요구되지 않고 PUSCH의 전송이 요구되는 경우(S402 단계에서 아니오, S405 단계에서 예), 가용 전력의 선형값(

)은 초기값(

)에서 PUSCH 전송 전력의 선형값이 감해진 값이고, (4) PUCCH 및 PUSCH의 전송이 요구되지 않는 경우(S402 단계에서 아니오, S405 단계에서 아니오), 가용 전력의 선형값(

)은 초기값(

)을 유지한다.That is, (1) when transmission of PUCCH and PUSCH is required (YES in step S402, YES in step S405), the linear value of the available power (

) Is the initial value (

In this case, the linear value of the PUCCH transmission power and the linear value of the PUSCH transmission power are subtracted, and (2) when transmission of the PUCCH is required and transmission of the PUSCH is not required (YES in step S402, NO in step S405), Linear value of available power (

) Is the initial value (

), The linear value of the PUCCH transmission power is subtracted, and (3) when the PUCCH transmission is not required and the PUSCH transmission is required (NO in step S402, YES in step S405), the linear value of available power (

) Is the initial value (

), The linear value of the PUSCH transmission power is subtracted, and (4) when the transmission of the PUCCH and the PUSCH is not required (NO in step S402, NO in step S405), the linear value of available power (

) Is the initial value (

Keep).

Next, SRS transmission power is allocated (step S408). Details of the SRS transmit power allocation step (step S408) will be described later.

Next, it is determined whether the transmission power of the SRS is equal to or greater than a predetermined threshold value a (step S409). The threshold a is a value determined by Equation 5 or a value multiplied by a predetermined constant smaller than 1 (for example, 0.9).

In equations (6), (7) and (9), the total transmit power of the plurality of component carriers is the maximum transmit power across the plurality of cells. ), The scaling factor w (i) (0 ≦ w (i) ≦ 1) may be used to reduce the PUSCH transmission power of each component carrier. This is because retransmission is possible when a packet error occurs in PUSCH transmission, and the influence of the packet error is also limited to the corresponding subframe.

On the other hand, SRS is unlikely to change the transmission power flexibly like PUSCH. Since the SRS is a signal transmitted for the purpose of channel estimation, more than a certain level of transmission power is required for accurate channel estimation in the presence of noise. In addition, the effect of the SRS channel estimation is a plurality of subframes up to a certain period to obtain the channel information of the band.

)을 초과할 경우, 일정한 수준 이하로 SRS 전송 전력을 변화시키는 것은 바람직하지 않다.Therefore, in a multi-carrier environment, the transmit power of the UE is determined by the maximum transmit power across the plurality of cells.

), It is undesirable to change the SRS transmit power below a certain level.

If the transmission power of the SRS is greater than or equal to the predetermined threshold a (YES in step S409), the terminal 10 transmits the SRS with the transmission power calculated as described above (step S410). However, if the transmission power of the SRS is less than the predetermined threshold (a) (NO in step S409), the terminal 10 cancels the SRS transmission (step S411).

As mentioned above, the SRS is transmitted to estimate channel quality over a wideband, and can combine multiple narrowband SRS transmissions to cover the frequency band of interest. If one narrowband SRS transmission fails, the base station 20 must wait to receive the failed narrowband SRS to estimate the wideband channel quality, and the effect of the failed SRS transmission is of interest as well as the narrowband in which the SRS transmission failed. Spread across the frequency band. In addition, the effect of the SRS channel estimation is a plurality of subframes up to a certain period to obtain the channel information of the band.

Therefore, retransmission of the SRS is required when the SRS transmission is canceled. The terminal 10 transmits the canceled SRS at the next SRS transmission opportunity. SRS retransmission of the terminal 10 may follow a predetermined rule known to the terminal 10 and the base station 20. Alternatively, the SRS retransmission of the terminal 10 may occur at a possible time determined by the terminal 10, and information about the SRS retransmission may be transmitted from the terminal 10 to the base station 20. Alternatively, the SRS retransmission of the terminal 10 may be performed according to the instruction of the base station 20 that has not received the SRS.

The transmit power of the retransmitted SRS will be assigned priority over the transmit power of other SRSs other than the retransmission, as will be described later.

Hereinafter, step S408 of FIG. 4 for allocating SRS transmit power will be described in detail.

)은 가용 전력의 선형값(

)과 수학식 5에 의한 SRS 전송 전력의 선형값의 최소값이 된다. 그리하여, SRS 전송 전력의 선형값(

)은 다음의 수학식 10과 같이 표현된다.Linear value of SRS transmit power (

) Is the linear value of available power (

) And the minimum value of the linear value of the SRS transmission power by Equation (5). Thus, the linear value of the SRS transmit power (

) Is expressed by Equation 10 below.

&Quot; (10) &quot;

In Equation 10, the first row and the second row represent equations 5 as linear values.

는 단말이 다수의 셀 전체에서 최대 전송 전력

의 선형값이고,

는 수학식 4에서 규정된 PUCCH 전송 전력의 선형값이며,

는 수학식 2 또는 3, 그리고 수학식 6 내지 9에 의해 규정되는 각 PUSCH 전송 전력의 선형값의 합이다. PUSCH는 UCI를 갖는 PUSCH 및 UCI를 갖지 않는 PUSCH를 포함한다.In the third row

The maximum transmission power of the terminal in the entire number of cells

Is a linear value of

Is a linear value of the PUCCH transmit power defined in Equation 4,

Is the sum of the linear values of the respective PUSCH transmit powers defined by Equations 2 or 3 and Equations 6-9. The PUSCH includes a PUSCH with UCI and a PUSCH without UCI.

Equation 10 shows that PUCCH and PUSCH transmit powers are allocated first in the total transmit powers for a plurality of cells, and SRS transmit powers are allocated in the remaining powers.

Meanwhile, a plurality of component carriers and a plurality of SRSs may be transmitted in a single subframe.

6 illustrates an example of a PUSCH 601 being transmitted on a first CC CC0, an SRS 602 being transmitted on a second CC CC1, and an SRS 603 on a third CC CC2. Shows the case where is transmitted. In this case, two SRSs 602 and 603 are transmitted in the same subframe.

7 illustrates another example, a PUSCH 701 is initially transmitted on a first component carrier CC0, a PUSCH 702 is transmitted on a second component carrier CC1, and an SRS (on a third component carrier CC2). 703 is transmitted. After the transmission powers of the PUSCHs 701 and 702 are allocated, transmission of the SRS 703 fails because the transmission power of the SRS 703 is insufficient, and the SRS 706 is retransmitted at the next transmission opportunity. In the subframe where the SRS 706 is retransmitted, the PUSCH 704 is transmitted on the first CC CC0 and the SRS 705 is transmitted on the second CC CC1. In this case, two SRSs 705 and 706 are transmitted in the same subframe.

Transmission of a plurality of SRSs may occur in the following cases.

(1) In order to obtain channel information of a band required for each CC, SRSs may be simultaneously transmitted in a plurality of CCs.

(2) Aperiodic SRS transmission may overlap with periodic SRS transmission of other CCs.

(3) When SRS transmission fails and SRS is retransmitted, retransmission of the SRS may overlap with SRS transmission of another CC.

SRS is transmitted in order to estimate channel quality in wideband and may combine multiple narrowband SRS transmissions to cover the frequency band of interest. If one narrowband SRS transmission fails, the base station 20 must wait to receive the failed narrowband SRS to estimate the wideband channel quality, and the effect of the failed SRS transmission is of interest as well as the narrowband in which the SRS transmission failed. Spread across the frequency band. Therefore, when multiple SRSs are transmitted at the same time, the resent SRSs have the highest priority.

Next, aperiodic SRS transmission occurs when the base station 20 commands the terminal 10 for SRS transmission without waiting for periodic SRS transmission. Therefore, aperiodic SRS transmissions have priority over periodic SRS transmissions.

Finally, after the retransmitted SRS and the transmit power of the aperiodic SRS are allocated, the transmit power of the periodic SRS is allocated.

On the other hand, when a plurality of SRS transmissions of the same nature occur in different component carriers simultaneously (in the same subframe), that is, when there are a plurality of retransmitted SRSs, when there are a plurality of aperiodic SRSs, or when there are a plurality of periodic SRSs, The SRS transmitted from the subcarrier (PCC) has priority over the SRS transmitted from the subcarrier (SCC). For SRSs transmitted from a plurality of subcarriers (SCCs), SRSs transmitted from a subcarrier (SCC) having a low serving cell index (c) have priority. Since the PCC is set to have the lowest serving cell index (c = 0), the SRS transmitted from the CC having the lowest serving cell index (c) has priority.

In summary,

(1) Priority in SRS transmit power allocation has the order of retransmission SRS, aperiodic SRS, periodic SRS,

(2) Among SRSs having the same property, SRSs transmitted from CCs having a low serving cell index (ServCellIndex) have priority.

This can be represented by the following Table 3.

[Table 3]

)은 다음의 수학식 11과 같이 표현된다.When the set of CCs on which the SRSs to be retransmitted are located is R, the linear value of the SRS transmission power to be retransmitted (

) Is expressed by Equation 11 below.

&Quot; (11) &quot;

In Equation 11, the first row and the second row are the same as Equation 10.

는 단말이 다수의 셀 전체에서 최대 전송 전력

의 선형값이고,

는 수학식 4에서 규정된 PUCCH 전송 전력의 선형값이며,

는 수학식 2 또는 3, 그리고 수학식 6 내지 9에 의해 규정되는 각 PUSCH 전송 전력의 선형값의 합이다. PUSCH는 UCI를 갖는 PUSCH 및 UCI를 갖지 않는 PUSCH를 포함한다.

는 전송 전력을 구하고자 하는 재전송 SRS보다 낮은 서빙 셀 인덱스에서 전송되는 재전송 SRS의 전송 전력의 선형값의 합이다. 재전송 SRS가 하나이거나 재전송 SRS가 프라이머리 셀(PCC)에서 전송되는 경우

는 0이다.In the third row

The maximum transmission power of the terminal in the entire number of cells

Is a linear value of

Is a linear value of the PUCCH transmit power defined in Equation 4,

Is the sum of the linear values of the respective PUSCH transmit powers defined by Equations 2 or 3 and Equations 6-9. The PUSCH includes a PUSCH with UCI and a PUSCH without UCI.

Is the sum of the linear values of the transmit power of the retransmitted SRS transmitted at the serving cell index lower than the retransmitted SRS for which the transmit power is to be obtained. One retransmission SRS or retransmission SRS is transmitted in the primary cell (PCC)

Is zero.

Equation 11 indicates that the transmit power of the retransmission SRS transmitted in the cell having the PUCCH, the PUSCH and the lower serving cell index is allocated first in the total transmit power for the plurality of cells, and the retransmission SRS transmit power is allocated in the remaining power. .

)은 다음의 수학식 12와 같이 표현된다.If the set of CCs in which the aperiodic SRS is located is S, the linear value of the aperiodic SRS transmission power (

) Is expressed by Equation 12 below.

[Equation 12]

In Equation 12, the first row and the second row are the same as Equation 10.

는 단말이 다수의 셀 전체에서 최대 전송 전력

의 선형값이고,

는 수학식 4에서 규정된 PUCCH 전송 전력의 선형값이며,

는 수학식 2 또는 3, 그리고 수학식 6 내지 9에 의해 규정되는 각 PUSCH 전송 전력의 선형값의 합이다. PUSCH는 UCI를 갖는 PUSCH 및 UCI를 갖지 않는 PUSCH를 포함한다.

는 수학식 11에 의해 규정되는 재전송 SRS의 전송 전력의 선형값의 합이다.

는 전송 전력을 구하고자 하는 비주기적 SRS보다 낮은 서빙 셀 인덱스에서 전송되는 비주기적 SRS의 전송 전력의 선형값의 합이다. 비주기적 SRS가 하나이거나 비주기적 SRS가 프라이머리 셀(PCC)에서 전송되는 경우

는 0이다.In the third row

The maximum transmission power of the terminal in the entire number of cells

Is a linear value of

Is a linear value of the PUCCH transmit power defined in Equation 4,

Is the sum of the linear values of the respective PUSCH transmit powers defined by Equations 2 or 3 and Equations 6-9. The PUSCH includes a PUSCH with UCI and a PUSCH without UCI.

Is the sum of the linear values of the transmit powers of the retransmission SRS defined by Equation (11).

Is the sum of the linear values of the transmit power of the aperiodic SRS transmitted at the serving cell index lower than the aperiodic SRS for which the transmit power is to be obtained. One aperiodic SRS or aperiodic SRS is transmitted in the primary cell (PCC)

Is zero.

Equation 12 is first assigned transmit power of aperiodic SRS transmitted in a cell with PUCCH, PUSCH, retransmission SRS and lower serving cell index in the total transmit power for multiple cells, and aperiodic SRS transmit power in remaining power. Indicates that this is assigned.

)은 다음의 수학식 13과 같이 표현된다.Next, the linear value of the periodic SRS transmit power (

) Is expressed by Equation 13 below.

&Quot; (13) &quot;

In Equation 13, the first row and the second row are the same as Equation 10.

는 단말이 다수의 셀 전체에서 최대 전송 전력

의 선형값이고,

는 수학식 4에서 규정된 PUCCH 전송 전력의 선형값이며,

는 수학식 2 또는 3, 그리고 수학식 6 내지 9에 의해 규정되는 각 PUSCH 전송 전력의 선형값의 합이다. PUSCH는 UCI를 갖는 PUSCH 및 UCI를 갖지 않는 PUSCH를 포함한다.

는 수학식 11에 의해 규정되는 재전송 SRS의 전송 전력의 선형값의 합이다.

는 수학식 12에 의해 규정되는 비주기적 SRS의 전송 전력의 선형값의 합이다.

는 전송 전력을 구하고자 하는 주기적 SRS보다 낮은 서빙 셀 인덱스에서 전송되는 주기적 SRS의 전송 전력의 선형값의 합이다. 주기적 SRS가 하나이거나 주기적 SRS가 프라이머리 셀(PCC)에서 전송되는 경우

는 0이다.In the third row

The maximum transmission power of the terminal in the entire number of cells

Is a linear value of

Is a linear value of the PUCCH transmit power defined in Equation 4,

Is the sum of the linear values of the respective PUSCH transmit powers defined by Equations 2 or 3 and Equations 6-9. The PUSCH includes a PUSCH with UCI and a PUSCH without UCI.

Is the sum of the linear values of the transmit powers of the retransmission SRS defined by Equation (11).

Is the sum of the linear values of the transmit power of the aperiodic SRS defined by Equation (12).

Is the sum of the linear values of the transmit power of the periodic SRS transmitted at the serving cell index lower than the periodic SRS for which the transmit power is to be obtained. One periodic SRS or periodic SRS is transmitted in a primary cell (PCC)

Is zero.

Equation (13) is first assigned the transmit power of a periodic SRS transmitted in a cell with PUCCH, PUSCH, retransmitted SRS, aperiodic SRS, and lower serving cell index at the total transmit power for multiple cells, and the periodic SRS at remaining power. Indicates that transmit power is allocated.

In summary, when there is one SRS transmission in a subframe, the SRS transmission power is determined by Equation 10. When a plurality of SRS transmissions exist in a subframe, the transmission power of the retransmission SRS is determined by Equation 11, the transmission power of the aperiodic SRS is determined by Equation 12, and the transmission power of the periodic SRS is Equation 13 Determined by

8 is a functional block diagram of a terminal device according to an embodiment of the present invention.

Referring to FIG. 8, the terminal device 800 according to an embodiment of the present invention may include a transmit power calculator 801 and a transmit power calculator 801 that calculate transmit power of PUCCH, PDCCH, and SRS in each serving cell. The transmission power control unit 802 controls the uplink transmission power of the terminal device 800 with the transmission power calculated by.

)에 의해 제한되고, 전체 셀에서 PUSCH 및 SRS의 전송 전력은 다수의 셀 전체에서 최대 전송 전력(

)에 의해 제한된다. 그리하여, SRS의 전송 전력은 다수의 셀 전체에서 최대 전송 전력(

)에서 PUCCH 및 PUSCH의 전송 전력이 할당되고 남은 전력에 의해 제한된다.The transmit power calculator 801 allocates transmit power in the order of PUCCH, PUSCH, and SRS. The transmit power of PUCCH, PUSCH, and SRS in each cell is the maximum transmit power in one cell (

And the transmit power of the PUSCH and SRS in the entire cell is determined by the maximum transmit power (

Limited by). Thus, the transmit power of an SRS is determined by the maximum transmit power across multiple cells.

Transmit power of the PUCCH and the PUSCH is limited by the remaining power.

When a plurality of SRSs are transmitted in one subframe, the transmit power calculator 801 allocates transmit power in the order of retransmitted SRS, aperiodic SRS, and periodic SRS. When a plurality of SRSs having the same property are transmitted, the transmit power calculator 801 first allocates transmit power to SRSs transmitted from a serving cell having a low serving cell index (ServCellIndex). The transmit power of each SRS is limited by the transmit power allocated to PUCCH, PUSCH, and other higher priority SRS.

The terminal device 800 may further include an SRS power determination unit 803 that determines whether the transmission power of the SRS calculated by the transmission power calculation unit 801 is greater than or equal to a predetermined threshold value. When the SRS power determination unit 803 determines that the transmission power of the SRS calculated by the transmission power calculation unit 801 is smaller than a predetermined threshold value, the transmission power control unit 802 is calculated by the transmission power calculation unit 801. Even if the linear value of the transmission power of the SRS is not 0, the transmission of the SRS is cancelled.

9 is a flowchart illustrating an SRS receiving method of a base station according to an embodiment of the present invention.

Referring to FIG. 9, the base station 20 receives an uplink signal from the terminal (step S901). The uplink signal received by the base station 20 includes uplink control information through the PUCCH, uplink data through the PUSCH, and a reference signal including the SRS.

The base station 20 determines whether the SRS is received when the SRS is to be received by a predetermined rule or an appointment with the terminal 10 (step S902). As described above, when the power that can be allocated by the terminal 10 for transmitting the SRS is smaller than a predetermined threshold, the terminal 10 does not transmit the SRS, and thus the base station 20 may receive the SRS. none.

When the base station 20 does not receive the SRS (NO in step S902), the base station 20 waits until the terminal 10 retransmits the SRS that failed to transmit (step S903). When the terminal 10 retransmits the SRS, it may be based on a predetermined rule that both the terminal 10 and the base station 20 know. Alternatively, when the terminal 10 retransmits the SRS, it is determined by the terminal 10, and information about the SRS retransmission of the terminal 10 may be transmitted from the terminal 10 to the base station 20. Alternatively, the base station 20 may transmit an instruction for SRS retransmission to the terminal 10. The uplink scheduling of the base station 20 waits until the SRS that fails to receive is received.

10 is a functional block diagram of a base station according to an embodiment of the present invention.

Referring to FIG. 10, the base station 1000 according to an embodiment of the present invention includes an uplink receiver 1001, an SRS receiver 1002, and an uplink scheduler 1003.

The uplink receiver 1001 receives an uplink signal from the terminal. The uplink signal received by the uplink receiver 1001 includes uplink control information through a PUCCH, uplink data through a PUSCH, and a reference signal including an SRS.

The SRS extractor 1002 extracts an SRS from an uplink signal received by the uplink receiver 1001. The SRS extracted by the SRS extractor 1002 is used to set uplink scheduling in the uplink scheduler 1003.

SRS extracting unit 1002 when the power to be allocated by the terminal for transmitting the SRS is less than a predetermined threshold value, the terminal fails to transmit the SRS, so that the SRS should be received by a predetermined rule or an appointment with the terminal. May not be able to extract the SRS.

When the SRS extractor 1002 does not receive the SRS, the SRS extractor 1002 waits until the terminal can receive the SRS retransmitted. When the terminal retransmits the SRS may be based on a predetermined rule known to both the terminal and the base station. Alternatively, when the terminal retransmits the SRS is determined by the terminal, information about the SRS retransmission of the terminal may be transmitted from the terminal to the base station. Alternatively, the base station may transmit an indication for SRS retransmission to the terminal. In addition, the SRS extractor 1002 waits for uplink scheduling of the uplink scheduler 1003 until an SRS that fails to receive is received.

 The above-described embodiments have described transmission power control of the SRS as an example of an uplink reference signal. However, the present invention is not limited thereto and may be applied to other uplink reference signals other than SRS.

While the present invention has been described in connection with what is presently considered to be the most practical and preferred embodiments, it is to be understood that the invention is not limited to the disclosed embodiments. In other words, within the scope of the present invention, all of the components may be selectively operated in combination with one or more. In addition, although all of the components may be implemented in one independent hardware, each or some of the components may be selectively combined to perform a program module that performs some or all functions combined in one or a plurality of hardware. It may be implemented as a computer program having. Codes and code segments constituting the computer program may be easily inferred by those skilled in the art. Such a computer program may be stored in a computer readable medium, and read and executed by a computer, thereby implementing embodiments of the present invention. As the storage medium of the computer program, a magnetic recording medium, an optical recording medium, a carrier wave medium, or the like may be included.

In addition, the terms "comprise", "comprise", or "having" described above mean that the corresponding component may be included, unless otherwise stated, and thus excludes other components. It should be construed that it may further include other components instead. All terms, including technical and scientific terms, have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs, unless otherwise defined. Terms used generally, such as terms defined in a dictionary, should be interpreted to coincide with the contextual meaning of the related art, and shall not be interpreted in an ideal or excessively formal sense unless explicitly defined in the present invention.

The foregoing description is merely illustrative of the technical idea of the present invention, and various changes and modifications may be made by those skilled in the art without departing from the essential characteristics of the present invention. Therefore, the embodiments disclosed in the present invention are intended to illustrate rather than limit the scope of the present invention, and the scope of the technical idea of the present invention is not limited by these embodiments. The protection scope of the present invention should be interpreted by the following claims, and all technical ideas within the equivalent scope should be interpreted as being included in the scope of the present invention.

Claims (20)

A reference signal transmission power control method in a communication system,
Calculating transmission power of an uplink control channel (PUCCH) and an uplink data channel (PUSCH) transmitted simultaneously with the uplink reference signal; And
Calculating a transmission power of an uplink reference signal,
The upper limit value of the transmission power of the uplink reference signal is the remaining power after the transmission power of the uplink control channel and the uplink data channel transmitted simultaneously with the uplink reference signal at the maximum transmission power in a plurality of cells. Reference signal transmission power control method. The method of claim 1,
The uplink reference signal is a reference signal transmission power control method, characterized in that the SRS (Sounding Reference Signal). The method of claim 2,
The transmission power of the SRS is calculated by the following equation.

In the above equation,

Is a linear value of the maximum transmit power in the serving cell (c),

Is an offset value,

CRS resource allocation bandwidth,

Is the received power to be guaranteed in transmitting the PUSCH,

Is the path loss compensation degree,

Path loss,

Is the power regulation value,

Is the maximum transmit power across multiple cells,

Is a linear value of uplink control channel transmit power, and

Is the sum of the linear values of the uplink data channel transmit power. The method of claim 2,
When a plurality of SRSs are transmitted at the same time, the transmission power of the SRS retransmitted is first calculated from the remaining power to which the transmission power of the uplink control channel and the uplink data channel are allocated, and the upper limit of the transmission power of the SRS that is not retransmitted is And transmitting power of the uplink control channel, the uplink data channel, and the retransmitted SRS at the maximum transmit power in the plurality of cells, and remaining power. The method of claim 4, wherein
And when the plurality of retransmitted SRSs are transmitted at the same time, the transmission power of the SRS retransmitted through the serving cell having a low serving cell index is allocated first. The method of claim 5, wherein
The transmission power of the retransmitted SRS is calculated by the following equation.

In the above equation,

Is a linear value of the maximum transmit power in the serving cell (c),

Is an offset value,

CRS resource allocation bandwidth,

Is the received power to be guaranteed in transmitting the PUSCH,

Is the path loss compensation degree,

Path loss,

Is the power regulation value,

Is the maximum transmit power across multiple cells,

Is a linear value of uplink control channel transmit power,

Is the sum of the linear values of the uplink data channel transmit power, and

Is the sum of the linear values of the transmit power of the SRS retransmitted in the serving cell having a value smaller than the serving cell index c. The method of claim 4, wherein
The transmission power of the aperiodic SRS is first calculated from the remaining power to which the transmission power of the uplink control channel, the uplink data channel, and the retransmitted SRS is allocated, and the upper limit of the transmission power of the periodic SRS is the maximum transmission in the entire plurality of cells. The power control method of the reference signal transmission power, characterized in that the remaining power is allocated to the transmission power of the uplink control channel, uplink data channel, retransmitted SRS and aperiodic SRS. The method of claim 7, wherein
And when a plurality of aperiodic SRSs are simultaneously transmitted, the transmit power of the aperiodic SRS transmitted through the serving cell having a low serving cell index is allocated first. The method of claim 8,
The transmission power of the aperiodic SRS is calculated by the following equation.

In the above equation,

Is a linear value of the maximum transmit power in the serving cell (c),

Is an offset value,

CRS resource allocation bandwidth,

Is the received power to be guaranteed in transmitting the PUSCH,

Is the path loss compensation degree,

Path loss, Is the power regulation value,

Is the maximum transmit power across multiple cells,

Is a linear value of uplink control channel transmit power,

Is the sum of the linear values of the uplink data channel transmit power,

Is the sum of the linear values of the transmission power of the SRS to be retransmitted, and

Is the sum of the linear values of the transmit power of the aperiodic SRS transmitted in the serving cell having a value smaller than the serving cell index c. The method of claim 7, wherein
When a plurality of periodic SRS is transmitted at the same time, the transmission power control method of the reference signal, characterized in that the transmission power of the periodic SRS transmitted through the serving cell with a low serving cell index is assigned first. 11. The method of claim 10,
The transmission power of the periodic SRS is calculated by the following equation.

In the above equation,

Is a linear value of the maximum transmit power in the serving cell (c),

Is an offset value,

CRS resource allocation bandwidth,

Is the received power to be guaranteed in transmitting the PUSCH,

Is the path loss compensation degree,

Path loss,

Is the power regulation value,

Is the maximum transmit power across multiple cells,

Is a linear value of uplink control channel transmit power,

Is the sum of the linear values of the uplink data channel transmit power,

Is the sum of the linear values of the transmission power of the SRS to be retransmitted,

Is the sum of the linear values of the transmit power of the aperiodic SRS, and

Is the sum of the linear values of the transmit power of the periodic SRS transmitted in the serving cell having a value smaller than the serving cell index c. The method of claim 1,
When a plurality of uplink reference signals are transmitted at the same time, the transmission power control method characterized in that the transmission power is allocated in the order of retransmitted uplink reference signal, aperiodic uplink reference signal, the periodic uplink reference signal. 13. The method of claim 12,
If a plurality of uplink reference signals having the same property is transmitted at the same time, the transmission power of the uplink reference signal transmitted through the serving cell with a low serving cell index is allocated first, characterized in that the transmission power control method. The method of claim 1,
Canceling transmission of the uplink reference signal when the transmission power of the uplink reference signal is smaller than a predetermined threshold value (a). 15. The method of claim 14,
The uplink reference signal is a sounding reference signal (SRS),
The threshold value (a) is a reference signal transmission power control method characterized in that determined by the following equation.

In the above equation,

Is the maximum transmit power in the serving cell (c),

Is an offset value,

CRS resource allocation bandwidth,

Is the received power to be guaranteed in transmitting the PUSCH,

Is the path loss compensation degree,

The path loss, and

Is the power regulation value. A transmit power calculator configured to calculate transmit power of an uplink control channel, an uplink data channel, and an uplink reference signal; And
A transmit power controller configured to control an uplink transmit power by the transmit power calculated by the transmit power calculator;
The upper limit value of the transmission power of the uplink reference signal is the remaining power after the transmission power of the uplink control channel and the uplink data channel transmitted simultaneously with the uplink reference signal at the maximum transmission power in a plurality of cells. Reference signal transmission power control device. 17. The method of claim 16,
When a plurality of uplink reference signals are transmitted at the same time, the transmission power control apparatus for the reference signal, characterized in that the transmission power is allocated in the order of the retransmitted uplink reference signal, aperiodic uplink reference signal, the periodic uplink reference signal. The method of claim 17,
When a plurality of uplink reference signals having the same property is transmitted at the same time, the reference signal transmission power control apparatus characterized in that the transmission power of the uplink reference signal transmitted through the serving cell with a low serving cell index is assigned first. 17. The method of claim 16,
The apparatus may further include an uplink reference signal power determination unit configured to determine whether a transmission power of the uplink reference signal is greater than or equal to a predetermined threshold value (a).
And the power control unit cancels transmission of an uplink reference signal when the transmission power of the uplink reference signal is smaller than the threshold value. 17. The method of claim 16,
The uplink reference signal is a reference signal transmission power control device, characterized in that the SRS (Sounding Reference Signal).

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