KR20120016520A - Method and apparatus for transmitting aperiodic srs(sounding reference signal) - Google Patents

Abstract

PURPOSE: An aperiodic SRS(Sound Retrieval System) transmission method is provided to prevent a collision between periodic SRS and aperiodic SRS by including an antenna for the aperiodic SRS. CONSTITUTION: A terminal aperiodically receives an SRS transmission request from a base station through an PDCCH(Physical Downlink Control CHannel). The terminal receives parameter information which is necessary for an aperiodic SRS transmission step by using a PPCCH signal and RRC(Radio Resource Control) signal(101). The terminal establishes a parameter which is necessary for a SRS transmission step(103). The terminal transmits an aperiodic SRS signal from a sub frame which receives the aperiodic SRS transmission request to the base station(104).

Description

Aperiodic SRS transmission method and apparatus {METHOD AND APPARATUS FOR TRANSMITTING APERIODIC SRS (SOUNDING REFERENCE SIGNAL)}

The present invention relates to an aperiodic Sounding Reference Signal (SRS) transmission method and apparatus, and includes transmission parameters such as transmission band, transmission time, antenna and CS (cyclic shift) value of an aperiodic SRS. It is about how to set.

In a Long Term Evolution (LTE) system, terminals transmit periodic SRS (sounding reference signal), and the base station uses periodic SRS information of each terminal, and the uplink channel state from each terminal to the base station After the measurement, the UE schedules a frequency resource and a modulation and coding scheme (MCS) to be used in the uplink. In order for the terminal to transmit such periodic SRS information, the base station sets the cell specific periodic SRS BW (BandWidth, bandwidth) information differently according to the cell and the UE specific (UE specific). ) Information such as periodic SRS BW, transmission start position in frequency resource, cyclic shift (CS), and transmission comb (transmission comb) is informed through RRC (Radio Resource Control) signaling. The UE sets parameters for periodic SRS transmission using such information, and transmits periodic SRS in a corresponding subframe.

LTE-Advanced (LTE-A) system has introduced aperiodic SRS transmission as well as periodic SRS transmission as uplink uses multiple transmit and receive antennas. However, a method for determining whether the base station informs the UE of parameters necessary for aperiodic SRS transmission and for aperiodic SRS transmission without collision with existing periodic SRS transmission resources. This is necessary.

It is an object of the present invention to provide a method and apparatus for aperiodic SRS transmission in which aperiodic SRS transmission is performed without collision with periodic SRS transmission.

In order to achieve the above object, according to an embodiment of the present invention, a method for transmitting an aperiodic (Sounding Reference Signal) of the UE (UE), the UE is a physical downlink control channel PNCCH (PDCCH) from the base station (eNB) Receiving aperiodic SRS transmission request through the; Information receiving step for the terminal to receive parameter information necessary for aperiodic SRS transmission using any one or more of PDCCH and Radio Resource Control (RRC) signaling from the base station, A parameter setting step of setting, by the terminal, a parameter required for SRS transmission using the received parameter information; and a base station performing aperiodic SRS in a corresponding subframe in which the terminal receives the aperiodic SRS transmission request using the set parameter. And transmitting to the.

In order to achieve the above-described problem, according to an embodiment of the present invention, a method for receiving an aperiodic sounding reference signal (SRS) of a base station (eNB), the base station to the UE (Physical Downlink Control CHannel) Transmitting an aperiodic SRS transmission request through the CRS, a parameter setting step for setting a parameter required for SRS transmission of the terminal, and the base station using any one or more of PDCCH and RRC (Radio Resource Control) signaling to the terminal. An information transmitting step of transmitting parameter information of the set parameter and receiving aperiodic SRS from the terminal in a corresponding subframe in which the base station receives the aperiodic SRS transmission request using the set parameter.

In order to achieve the above object, the UE for transmitting an aperiodic Sounding Reference Signal (SRS) according to an embodiment of the present invention, through a physical downlink control channel (PDCCH) from the base station (eNB) Receives aperiodic SRS transmission request, receives parameter information necessary for aperiodic SRS transmission from the base station using any one or more of PDCCH and RRC (Radio Resource Control) signaling, and transmits SRS using the received parameter information A terminal parameter setting unit for setting a parameter required for the and a transmission antenna for transmitting the aperiodic SRS to the base station in the subframe in which the terminal transmits the aperiodic SRS transmission request using the set parameter.

In order to achieve the above object, the base station (eNB) receiving an aperiodic Sounding Reference Signal (SRS) according to an embodiment of the present invention, the terminal (UE) through the PDCCH (Physical Downlink Control CHannel) A base station transmitting aperiodic SRS transmission request, setting a parameter required for SRS transmission of the terminal, and transmitting parameter information of the set parameter to the terminal using any one or more of PDCCH and Radio Resource Control (RRC) signaling. And a base station including a parameter setting unit and a reception antenna for receiving an aperiodic SRS from the terminal in a corresponding subframe in which the aperiodic SRS transmission request is transmitted using the set parameter.

Specific details of other embodiments are included in the detailed description and drawings.

According to an embodiment of the present invention, periodic SRSs and aperiodic SRSs transmitted by other terminals do not collide with each other. In addition, according to an embodiment of the present invention, there is an effect of preventing the increase of physical downlink control channel (PDCCH) control information.

1 is a flowchart illustrating a parameter setting process of a UE for aperiodic SRS transmission according to the first embodiment.
2 is a flowchart of a parameter setting procedure of an eNB for aperiodic SRS transmission according to Embodiment 1 of the present invention.
3 is a block diagram of a terminal for aperiodic SRS transmission according to Embodiment 1 of the present invention.
4 is a block diagram of a base station for aperiodic SRS reception according to Embodiment 1 of the present invention.
5 is a flowchart of an aperiodic SRS transmission procedure according to Embodiment 2 of the present invention.
FIG. 6 is a flowchart illustrating a process of setting, by the UE, a CS value and a Comb value required for aperiodic SRS transmission using a CSI value of an UL grant.
FIG. 7 is a flowchart illustrating a process of setting, by the UE, a CS value, a Comb value, and the number of transmit antenna ports required for aperiodic SRS transmission using a CSI value of an UL grant.

Hereinafter, embodiments of the present invention will be described in detail with the accompanying equations and drawings. In addition, in describing the present invention, when it is determined that a detailed description of a related known function or configuration may unnecessarily obscure the subject matter of the present invention, the detailed description thereof will be omitted. The following terms are defined in consideration of the functions of the present invention, and may be changed according to the intentions or customs of the user, the operator, and the like. Therefore, the definition should be based on the contents throughout this specification.

In addition, in describing the embodiments of the present invention, an OFDM (orthogonal frequency multiple division) based wireless communication system, in particular, 3GPP EUTRA (or LTE) or Advanced E-UTRA (or LTE-A) standard Although the main subject matter of the present invention, the main subject matter of the present invention can be applied to other communication systems having a similar technical background and channel form with a slight modification without departing from the scope of the present invention. It will be possible at the discretion of those skilled in the art.

According to the present invention, in order to transmit aperiodic SRS, the UE selectively sets information necessary for aperiodic SRS transmission by using RRC signaling and PDCCH (Physical Downlink Control CHannel) information from the base station in LTE-Advanced system. It is about technology to do. In other words, the UE may set parameters related to aperiodic SRS transmission through RRC signaling from the base station, and the UE implicitly or may select parameters related to aperiodic SRS transmission through the PDCCH from the base station. You can set it explicitly. In addition, by using the RRC signaling and the PDCCH from the base station selectively, the terminal may configure parameters necessary for SRS transmission. In one embodiment, aperiodic SRS bandwidth (BW) can be implicitly set using Modulation and Coding Scheme (MCS) information (ie, I _MCS ) of the PDCCH for aperiodic SRS transmission. In this case, an aperiodic SRS BW may be set among cell specific periodic SRS BWs.

In the following embodiments, the setting of aperiodic SRS transmission parameters is described separately, but all parameters necessary for aperiodic SRS transmission are simultaneously configured or some of the parameters are set by RRC signaling and PDCCH control information. May optionally be set.

≪ Example 1 >

In Embodiment 1, parameter setting for aperiodic SRS transmission is performed by selectively using RRC signaling information and PDCCH information for aperiodic SRS transmission received from the base station by the UE for aperiodic SRS transmission. Describe the process.

1 is a flowchart illustrating a parameter setting process of a UE for aperiodic SRS transmission according to the first embodiment.

Referring to FIG. 1, a UE is allocated parameters necessary for aperiodic SRS transmission using RRC signaling from an eNB (101). The UE receives an aperiodic SRS transmission request by the PDCCH (UL grant or DL grant) from the base station and simultaneously allocates necessary parameters explicitly or implicitly (102). In this case, when explicitly allocated, a resource (bit for control information) for informing parameters necessary for aperiodic SRS transmission is allocated to a UL grant (or DL grant). do. On the contrary, when implicitly allocated, resources for parameters required for aperiodic SRS transmission are not allocated to the UL grant (or DL grant), but specific parameter information of the UL grant (or DL grant) (eg, It is possible to implicitly link I _MCS ) with information related to aperiodic SRS transmission (eg, aperiodic SRS BW). UE selectively uses aperiodic RRC signaling and PDCCH information for parameters necessary for aperiodic SRS transmission (eg, SRS BW, frequency-domain starting position, number of transmitting antennas, CS (cyclic shift)) And Comb) are set (103). The UE transmits an aperiodic SRS in a corresponding subframe, that is, a subframe in which an aperiodic SRS transmission is requested according to the set value (104).

2 is a flowchart of a parameter setting procedure of an eNB for aperiodic SRS transmission according to Embodiment 1 of the present invention.

Referring to FIG. 2, an eNB transmits parameters necessary for aperiodic SRS transmission to an UE via RRC signaling (201). The base station explicitly or implicitly allocates parameters necessary for aperiodic SRS transmission to UL grant or DL grant information using the PDCCH (202) and requests aperiodic SRS transmission of the terminal through the PDCCH ( 202). The base station receives an aperiodic SRS from the terminal in the corresponding subframe (203).

3 is a block diagram of a terminal for aperiodic SRS transmission according to Embodiment 1 of the present invention.

Referring to FIG. 3, the terminal parameter setting unit 301 sets parameters required for aperiodic SRS transmission through the RRC signaling and the PDCCH as described with reference to FIGS. 1 and 2. The sequence generator 302 generates a sequence for an aperiodic SRS transmission signal using the parameters set by the parameter setter 301. The frequency resource allocator 303 allocates a bandwidth and a start position for an aperiodic SRS transmission using the parameters set by the parameter setting unit 301. Subsequently, the IFFT unit 304 performs an inverse fast fourier transform (IFFT) on an aperiodic SRS signal. The IFFT aperiodic SRS signal is transmitted through the transmission antenna 305 according to the parameter set by the parameter setting unit 301.

4 is a block diagram of a base station for aperiodic SRS reception according to Embodiment 1 of the present invention. Referring to FIG. 4, the base station parameter setting unit 401 sets parameters for aperiodic SRS reception of each UE, and sets the parameters through RRC signaling and PDCCH as described with reference to FIGS. 1 and 2. A parameter required for aperiodic SRS transmission is transmitted to the terminal. Receive antennas 402 receive an aperiodic SRS signal in the corresponding subframe. The DFT unit 403 performs a discrete Fourier transform (DFT) on the received aperiodic SRS signal. Thereafter, the SRS information separator 404 separates the information by the aperiodic SRS of each terminal from the aperiodic SRS signal, which is DFT, using the parameters set by the base station parameter setting unit 401. The scheduling unit 405 estimates channel state information between a corresponding terminal and a base station from information by an aperiodic SRS, using the parameters set by the base station parameter setting unit 401, and transmits data for the terminal. Schedule.

Aperiodic SRS frequency band (aperiodic SRS BW), frequency domain starting position, and CS (Cyclic) among the parameters required for aperiodic SRS transmission of the UE through the following embodiments The proposed methods are shown with respect to the setting of Shift) and Comb and the number of antennas.

<Example 2>

Aperiodic SRS BW

For aperiodic SRS transmission, the base station allocates an aperiodic SRS BW to each terminal, and each terminal should be configured to use an aperiodic SRS BW allocated thereto. To this end, a base station transmits information on an aperiodic SRS BW to a UE as (1) an implicitly associated method with an I _MCS, and (2) a periodic SRS BW. Method, and (3) a method using RRC signaling for aperiodic SRS transmission.

A. I _MCS Implicitly indicating an aperiodic SRS BW using

The UL grant (or DL grant) of the PDCCH includes control information required for transmission of an uplink or downlink data channel. Among these control information, the Modulation and Coding Scheme (MCS) may indicate information on modulation and coding of a data channel to be transmitted and is represented by I _MCS . In general, the higher the MCS, the better the channel condition, and the lower the MCS, the worse the channel condition. The present invention proposes to implicitly indicate an aperiodic SRS BW using I _MCS of PDCCH. In other words, without adding the control information field for the aperiodic SRS BW to the control information of the PDCCH (UL grant or DL grant), it is determined whether to select an aperiodic SRS BW by using the I _MCS information of the PDCCH. Implicitly instructs. An advantage of this implicit method is that it does not increase the overhead of the PDCCH since no additional control information field is added in the corresponding PDCCH. In the present invention, as an example in which an aperiodic SRS BW is implicitly indicated using a PDCCH control information field, it is assumed that I _MCS is used. However, in addition to the I _MCS , PDCCH has various control information parameters (for example, a precoding matrix index (PMI) and a cyclic shift indicator (CSI)), and implicitly indicates an aperiodic SRS BW. It is not intended to exclude the embodiment using fields.

The aperiodic SRS BW may also be selected from configured cell-specific periodic SRS BWs. In other words, the configured cell-specific periodic SRS BW delivered via RRC signaling for periodic SRS transmission is (1) the largest periodic SRS BW, (2) the second largest ( the second largest periodic SRS BW, (3) the third largest periodic SRS BW, and (4) the smallest periodic SRS BW. For example, there is a correspondence relationship between periodic SRS BW and aperiodic SRS BW.

* The largest aperiodic SRS BW = the largest periodic SRS BW

* The second largest aperiodic SRS BW = the second largest periodic SRS BW

* The third largest aperiodic SRS BW = the third largest periodic SRS BW

* The smallest aperiodic SRS BW = the smallest periodic SRS BW

The reason for using a cell specific periodic SRS BW as an aperiodic SRS BW is that the collision between the BWs during periodic and aperiodic SRS transmission is prevented. To prevent it.

Specific methods of notifying the aperiodic SRS BW to the I _MCS are as follows. Here, the I _MCS of the UL grant is described as an example, but the same method may be used in the DL grant.

A-1

The first method is to set the aperiodic SRS BW according to the modulation order of the I _MCS . As shown in Table 1, I _MCS 21 to I _MCS 28 with 64QAM modulation are assigned the largest aperiodic SRS BW, and I _MCS 11 to I with 16QAM modulation. _MCS 20 the second largest (the second largest) acyclic (aperiodic) assigns the SRS BW and, QPSK modulation (modulation) I _MCS 0 from I _MCS 10 third largest (the third largest) to by having a non-periodically by ( aperiodic) SRS BW is allocated. In this method, the modulation order and the size of the BW may be allocated differently. For example, if the largest aperiodic SRS BW is allocated to 64QAM, the second largest aperiodic SRS BW may be allocated to 16QAM and QPSK.

MCS Index
I _MCS Modulation Order Allocated aperiodic SRS BW 0 2 The third largest aperiodic SRS BW One 2 2 2 3 2 4 2 5 2 6 2 7 2 8 2 9 2 10 2 11 4 The second largest aperiodic SRS BW 12 4 13 4 14 4 15 4 16 4 17 4 18 4 19 4 20 4 21 6 The largest aperiodic SRS BW 22 6 23 6 24 6 25 6 26 6 27 6 28 6

A-2

The second method is to indicate an aperiodic SRS BW according to the range of I _MCS . As shown in Table 2, the largest aperiodic SRS BW is assigned to I _MCS between 21 and 28, and the second largest aperiodic to I _MCS between 14 and 20. assign the aperiodic SRS BW, assign the third largest aperiodic SRS BW to the I _MCS between 7 and 13, and the smallest to the I _MCS from 0 to 6. A) Assign an aperiodic SRS BW.

MCS Index
I _MCS Allocated aperiodic SRS BW 0-6 The smallest aperiodic SRS BW 7-13 The third largest aperiodic SRS BW 14-20 The second largest aperiodic SRS BW 21-28 The largest aperiodic SRS BW

If only two largest aperiodic SRS BWs are to be used, as indicated in Table 3, indicate the largest aperiodic SRS BW when I _MCS is between 14 and 28, and I _{When the MCS} is between 0 and 13, it may indicate the second largest aperiodic SRS BW.

MCS Index
I _MCS Allocated aperiodic SRS BW 0-13 The second largest aperiodic SRS BW 14-28 The largest aperiodic SRS BW

A-3

The third method is to indicate an aperiodic SRS BW according to a group of I _MCSs . Group the values of I _MCS to assign the largest aperiodic SRS BW to 3, 7, 11, 15, 19, 23, 27, as shown in Table 4, 2, 6, 10, 14 Assign the second largest aperiodic SRS BW to 18, 22, and 26, and the third largest to 1, 5, 9, 13, 17, 21, and 25. Allocate the aperiodic SRS BW and assign the smallest aperiodic SRS BW to 0, 4, 8, 12, 16, 20, 24, 28. As such, the method of indicating an aperiodic SRS BW according to a group of I _MCSs increases flexibility in selecting an aperiodic SRS BW, and an MCS for transmitting UL data is appropriately used. I can adjust it.

MCS Index
I _MCS Allocated aperiodic SRS BW 0, 4, 8, 12, 16, 20, 24,28 The smallest aperiodic SRS BW 1,5,9,13,17,21,25 The third largest aperiodic SRS BW 2,6,10,14,18,22,26 The second largest aperiodic SRS BW 3,7,11,15,19,23,27 The largest aperiodic SRS BW

If you want to use only the two largest aperiodic SRS BWs, as shown in Table 5, the largest I _MCS is even (eg 0, 2, 4, 6, ..., 28). assign the the largest aperiodic SRS BW and for the odd (eg 1, 3, 5, 7, ...., 27) I _MCS the second largest aperiodic ) Allocate SRS BW.

MCS Index
I _MCS Allocated aperiodic SRS BW Odd values
(1, 3, ..., 27) The second largest aperiodic SRS BW Even values (0, 2, 4, ..., 28) The largest aperiodic SRS BW

Contrary to Table 5, the largest aperiodic SRS BW is assigned to an I _{MCS that} is odd (e.g., 1, 3, 5, 7, ...., 27), and even (e.g. 0). It is also possible to set the second largest aperiodic SRS BW for I _MCS , (2, 4, 6, ..., 28).

5 is a flowchart of an aperiodic SRS transmission procedure according to Embodiment 2 of the present invention.

First, the UE acquires control information values required for UL or DL transmission from the base station through the PDCCH (501). It is checked whether there is an aperiodic SRS transmission request from the PDCCH control information field (502). If there is no aperiodic SRS transmission request, it waits for the next PDCCH reception, and if there is an aperiodic SRS transmission request, it is checked whether the I _MCS value is odd or even (503). If the I _MCS value is an even number, the largest aperiodic SRS BW is set to be used (504), and an aperiodic SRS is transmitted in a corresponding subframe (506). If the I _MCS value is odd, the second largest aperiodic SRS BW is set to be used (505), and an aperiodic SRS is transmitted in a corresponding subframe (507). As described above, the aperiodic SRS BW may be selected from configured cell-specific periodic SRS BWs. So far, a description has been given of a method implicitly indicated by I _MCS in PDCCH to configure an aperiodic SRS BW.

B. Using Periodic SRS BW

In order to set a BW for aperiodic SRS transmission, a periodic SRS BW may be used in the same manner. In other words, the UE uses the same BW in periodic SRS transmission and aperiodic SRS transmission. To this end, information about a periodic SRS BW is known to the UE before the aperiodic SRS transmission.

C. Announce aperiodic SRS BW information using RRC signaling

The base station may directly inform the terminal of BW information for aperiodic SRS transmission using RRC signaling.

&Lt; Example 3 >

Frequency Domain Starting Position

In order for the UE to transmit an aperiodic SRS, the UE needs to know from which point of time an aperiodic SRS starts. In order to inform the base station, there are three methods of (1) using RRC, (2) explicitly notifying through PDCCH, and (3) reusing frequency domain starting position used for periodic SRS transmission. This is possible.

A. Using RRC

The base station directly informs the terminal of the start position in the frequency domain for aperiodic SRS transmission using RRC signaling.

B. Explicitly inform the PDCCH

A control information field for indicating a start position in a frequency domain for aperiodic SRS transmission is added to an UL grant or a DL grant using a PDCCH.

C. Reuse of frequency domain starting position used in periodic SRS

A starting position in the frequency domain for aperiodic SRS transmission is made equal to a starting position in the frequency domain for periodic SRS transmission. To this end, before the UE transmits the aperiodic SRS, the BS informs the UE of the starting position in the frequency domain for the periodic SRS transmission.

<Example 4>

CS (Cyclic Shift) and Comb

(1) a method of implicitly indicating CS and Comb values using a Cyclic Shift Indicator (CSI) as a method of informing a terminal of a CS value and a corresponding Comb value for aperiodic SRS transmission of the UE to a UE; There are four methods: (2) how to use RRC, (3) how to explicitly notify using PDCCH, and (4) reuse of CS and Comb used in periodic SRS.

A. Implicitly indicates CS and Comb values using CSI

In the UL grant of the PDCCH, a control information field called a cyclic shift indicator (CSI) exists, and its original purpose is used to inform a CS value for generating a DM-RS (DeModulation Reference Signal) required for UL data transmission. The present invention proposes a method for implicitly setting a CS value and a Comb value for aperiodic SRS transmission using a CSI value used for DM-RS. Here, Comb is a parameter indicating whether to transmit with only even-numbered subcarriers or only odd-numbered subcarriers in an aperiodic SRS transmission. At this time, the CS values and the Comb values selected by the CSI value for the aperiodic SRS transmission are set to prevent collision with periodic SRS resources.

As shown in Table 6, eight CSI values can exist, and CS and Comb are set implicitly according to the CSI value. As shown in Table 6, when the UE transmits an aperiodic SRS using one antenna port, the CS for SRS transmission may be set equal to the CSI value, and the Comb value is an even CSI value. It can be set to 1 when 0 and the CSI value is odd.

CSI CS for aperiodic SRS Comb for aperiodic SRS 0 0 0 One One One 2 2 0 3 3 One 4 4 0 5 5 One 6 6 0 7 7 One

As shown in Table 7, if the terminal uses multiple antenna ports (for example, four antenna ports), four CS values are required for aperiodic SRS transmission. CS and Comb values for an aperiodic SRS may be implicitly set.

CSI CS for aperiodic SRS Comb for aperiodic SRS 0 0, 2, 4, 6 0 One 0, 2, 4, 6 One 2 1, 3, 5, 7 0 3 1, 3, 5, 7 One  4 0, 2, 4, 6 0 5 0, 2, 4, 6 One 6 1, 3, 5, 7 0 7 1, 3, 5, 7 One

As shown in Table 8, if the UE uses multiple antenna ports (for example, two antenna ports), two CS values are required for aperiodic SRS transmission. CS and Comb values for an aperiodic SRS may be set.

CSI CS for aperiodic SRS Comb for aperiodic SRS 0 0, 4 0 One 0, 4 One 2 1, 5 0 3 1, 5 One  4 2, 6 0 5 2, 6 One 6 3, 7 0 7 3, 7 One

FIG. 6 is a flowchart illustrating a process of setting, by the UE, a CS value and a Comb value required for aperiodic SRS transmission using a CSI value of an UL grant. First, the terminal acquires control information values necessary for UL data transmission from the base station through the PDCCH (601). It is checked whether there is an aperiodic SRS transmission request from the PDCCH control information field (602). If there is no aperiodic SRS transmission request, it waits for receiving the next PDCCH. If there is an aperiodic SRS transmission request, CS and Comb are implicitly set according to the CSI value in the PDCCH (603). An aperiodic SRS is transmitted in the frame (604).

B. Use RRC

The base station may directly inform the terminal of CS values and Comb values necessary for aperiodic SRS transmission using RRC signaling.

C. Explicitly informed using PDCCH

The base station may explicitly inform the user equipment of CS values and Comb values necessary for aperiodic SRS transmission using the PDCCH. To this end, a control information field for indicating a start position in a frequency domain for aperiodic SRS transmission is added to a PDCCH (UL grant or DL grant).

D. Reusing CS and Combs Used in Periodic SRS

For aperiodic SRS transmission, the CS and Comb values used for periodic SRS transmission are reused. To this end, before the UE performs aperiodic SRS transmission, CS and Comb information used for periodic SRS transmission should be known to the UE.

Example 5

Transmit Antenna Count

In order to set the number of transmit antenna ports used for aperiodic SRS transmission of the UE, (1) a method of implicitly indicating the number of transmit antenna ports using CSI, and (2) explicitly using PDCCH. There are three ways to inform, and (3) use RRC.

A. Implicitly indicating the number of transmit antenna ports using CSI

Whether the UE transmits an aperiodic SRS in only one transmit antenna mode or an aperiodic SRS in a multiple transmit antenna mode may be implicitly set using the CSI control information of the PDCCH. As shown in Table 9, when the CSI is 0, 1, 4, and 5, four CS values are given, and therefore, aperiodic SRS should be transmitted to four transmitting antenna ports. If the CSI is 2, 3, 6, or 7, since one CS value is given, an aperiodic SRS should be transmitted to one transmit antenna port.

CSI CS for aperiodic SRS Comb for aperiodic SRS 0 0, 2, 4, 6 0 One 0, 2, 4, 6 One 2 0 0 3 2 One  4 1, 3, 5, 7 0 5 1, 3, 5, 7 One 6 4 0 7 6 One

Referring to Table 10, when the CSI is 0, 1, 4, and 5, two CS values are given, and therefore, aperiodic SRS should be transmitted on two transmission antenna ports. If the CSI is 2, 3, 6, or 7, since one CS value is given, an aperiodic SRS must be transmitted through one transmitting antenna port.

CSI CS for aperiodic SRS Comb for aperiodic SRS 0 0, 4 0 One 2, 6 One 2 0 0 3 2 One  4 1, 5 0 5 3, 7 One 6 4 0 7 6 One

FIG. 7 is a flowchart illustrating a process of setting, by the UE, a CS value, a Comb value, and the number of transmit antenna ports required for aperiodic SRS transmission using a CSI value of an UL grant. First, the terminal acquires control information values necessary for UL data transmission from the base station through the PDCCH (701). It is checked whether there is an aperiodic SRS transmission request from the PDCCH control information field (702). If there is no aperiodic SRS transmission request, it waits for receiving the next PDCCH. If there is an aperiodic SRS transmission request, CS and Comb values are implicitly set according to the CSI value in the PDCCH (703). The number of transmit antenna ports is also set in proportion to the number of CSs set here (703), and transmits an aperiodic SRS in the corresponding subframe (704).

B. Explicitly informed using PDCCH

The base station sets whether aperiodic SRS transmission is made to one transmitting antenna port or several transmitting antenna ports to the terminal using the PDCCH. To this end, a control information field indicating the number of antennas used for aperiodic SRS transmission is added to a PDCCH (UL grant or DL grant).

C. RRC

The base station configures whether to use aperiodic SRS transmission in one antenna mode or multiple antenna modes using RRC signaling.

At this point, it will be understood that each block of the flowchart illustrations and combinations of flowchart illustrations may be performed by computer program instructions. Since these computer program instructions may be mounted on a processor of a general purpose computer, special purpose computer, or other programmable data processing equipment, those instructions executed through the processor of the computer or other programmable data processing equipment may be described in flow chart block (s). It creates a means to perform the functions. These computer program instructions may be stored in a computer usable or computer readable memory that can be directed to a computer or other programmable data processing equipment to implement functionality in a particular manner, and thus the computer usable or computer readable memory. It is also possible for the instructions stored in to produce an article of manufacture containing instruction means for performing the functions described in the flowchart block (s). Computer program instructions may also be mounted on a computer or other programmable data processing equipment, such that a series of operating steps may be performed on the computer or other programmable data processing equipment to create a computer-implemented process to create a computer or other programmable data. Instructions for performing the processing equipment may also provide steps for performing the functions described in the flowchart block (s).

In addition, each block may represent a portion of a module, segment, or code that includes one or more executable instructions for executing a specified logical function (s). It should also be noted that in some alternative implementations, the functions noted in the blocks may occur out of order. For example, the two blocks shown in succession may in fact be executed substantially concurrently, or the blocks may sometimes be executed in the reverse order, depending on the corresponding function.

Herein, the term &quot; part &quot; used in the present embodiment means a hardware component such as software or an FPGA or an ASIC, and 'part' performs certain roles. However, '~' is not meant to be limited to software or hardware. &Quot; to &quot; may be configured to reside on an addressable storage medium and may be configured to play one or more processors. Thus, as an example, '~' means components such as software components, object-oriented software components, class components, and task components, and processes, functions, properties, procedures, and the like. Subroutines, segments of program code, drivers, firmware, microcode, circuits, data, databases, data structures, tables, arrays, and variables. The functionality provided within the components and the 'parts' may be combined into a smaller number of components and the 'parts' or further separated into additional components and the 'parts'. In addition, the components and '~' may be implemented to play one or more CPUs in the device or secure multimedia card.

Those skilled in the art will appreciate that the present invention can be embodied in other specific forms without changing the technical spirit or essential features of the present invention. It is therefore to be understood that the above-described embodiments are illustrative in all aspects and not restrictive. The scope of the present invention is indicated by the scope of the following claims rather than the detailed description, and all changes or modifications derived from the meaning and scope of the claims and the equivalent concept are included in the scope of the present invention. Should be interpreted.

On the other hand, the present specification and the drawings have been described with respect to the preferred embodiments of the present invention, although specific terms are used, it is merely used in a general sense to easily explain the technical details of the present invention and help the understanding of the invention, It is not intended to limit the scope of the invention. It will be apparent to those skilled in the art that other modifications based on the technical idea of the present invention can be carried out in addition to the embodiments disclosed herein.

Claims (20)

In the aperiodic (Sounding Reference Signal) transmission method of the UE (UE),
Receiving, by the UE, an aperiodic SRS transmission request from a base station (eNB) through a physical downlink control channel (PDCCH);
An information receiving step of receiving, by the terminal, parameter information required for aperiodic SRS transmission using at least one of PDCCH and RRC (Radio Resource Control) signaling from the base station;
A parameter setting step of setting, by the terminal, a parameter required for SRS transmission using the received parameter information; And
And transmitting, by the terminal, the aperiodic SRS to the base station in a corresponding subframe in which the aperiodic SRS transmission request is received using the set parameter. The method of claim 1,
The information receiving step includes the terminal receiving an _MCS (index of Modulation and Coding Scheme) from the base station,
The parameter setting step includes setting the aperiodic SRS bandwidth corresponding to the received I _MCS to be used for aperiodic SRS transmission. The method of claim 1,
The information receiving step includes the terminal receiving a cyclic shift indicator (CSI) from the base station,
The parameter setting step includes setting a Comb value corresponding to the received CSI to be used for aperiodic SRS transmission. The method of claim 1,
The information receiving step includes the terminal receiving a cyclic shift indicator (CSI) from the base station,
The parameter setting step includes setting the number of transmit antenna ports corresponding to the received CSI to be used for aperiodic SRS transmission. The method of claim 1,
The parameter required for the SRS transmission includes an aperiodic SRS bandwidth (BW),
And wherein the aperiodic SRS bandwidth is set to any one of cell specific periodic SRS bandwidths. In the method for receiving an aperiodic sounding reference signal (SRS) of an eNB,
Transmitting, by the base station, an aperiodic SRS transmission request to a UE through a physical downlink control channel (PDCCH);
A parameter setting step of setting a parameter required for SRS transmission of the terminal;
An information transmitting step of transmitting, by the base station, parameter information of the set parameter to the terminal using any one or more of PDCCH and RRC (Radio Resource Control) signaling; And
And receiving, by the base station, aperiodic SRS from the terminal in a corresponding subframe in which the aperiodic SRS transmission request is received using the set parameter. The method of claim 6,
The parameter setting step includes setting the base station to use an aperiodic SRS bandwidth corresponding to an I _MCS (index of Modulation and Coding Scheme) corresponding to the terminal for aperiodic SRS reception,
The information transmitting step includes the step of the base station to transmit the I _MCS corresponding to the terminal to the terminal. The method of claim 6,
The parameter setting step includes setting a Comb value corresponding to a cyclic shift indicator (CSI) corresponding to the terminal to be used for aperiodic SRS reception.
The information transmitting step includes the step of the base station transmitting the CSI corresponding to the terminal to the terminal. The method of claim 6,
The parameter setting step includes setting the number of transmit antenna ports corresponding to a cyclic shift indicator (CSI) corresponding to the terminal to be used for aperiodic SRS reception.
The information transmitting step includes the step of the base station transmitting the CSI corresponding to the terminal to the terminal. The method of claim 6,
The parameter required for the SRS transmission includes an aperiodic SRS bandwidth (BW),
The aperiodic SRS bandwidth is aperiodic SRS receiving method characterized in that it is set to any one of the cell-specific periodic SRS bandwidth (cell specific). In a terminal (UE) transmitting an aperiodic sounding reference signal (SRS),
Receives an aperiodic SRS transmission request from a base station (NB) through a physical downlink control channel (PDCCH), and parameter information required for aperiodic SRS transmission using any one or more of PDCCH and RRC (Radio Resource Control) signaling from the base station A terminal parameter setting unit configured to receive a signal and to set a parameter required for SRS transmission using the received parameter information; And
And a transmission antenna for transmitting the aperiodic SRS to the base station in a corresponding subframe in which the terminal transmits the aperiodic SRS transmission request using the set parameter. The method of claim 11,
The terminal parameter setting unit receives an I _MCS (Index of Coding and Coding Scheme) from the base station,
And a frequency resource allocator configured to use the aperiodic SRS bandwidth corresponding to the received I _MCS for aperiodic SRS transmission. The method of claim 11,
The terminal parameter setting unit receives a cyclic shift indicator (CSI) from the base station,
And a frequency resource allocator configured to set a Comb value corresponding to the received CSI to be used for aperiodic SRS transmission. The method of claim 11,
The terminal parameter setting unit receives a cyclic shift indicator (CSI) from the base station, and the terminal characterized in that configured to use the number of transmit antenna ports corresponding to the received CSI for aperiodic SRS transmission. The method of claim 11,
The parameter required for the SRS transmission includes an aperiodic SRS bandwidth (BW),
And wherein the aperiodic SRS bandwidth is set to one of cell specific periodic SRS bandwidths. In the base station (eNB) for receiving an aperiodic sounding reference signal (SRS),
Transmitting an aperiodic SRS transmission request through a physical downlink control channel (PDCCH) to a UE, setting parameters required for SRS transmission of the terminal, and transmitting any one of PDCCH and RRC (Radio Resource Control) signaling to the terminal. A base station parameter setting unit which transmits parameter information of the set parameter using the above; And
And a receiving antenna for receiving an aperiodic SRS from the terminal in a corresponding subframe in which the aperiodic SRS transmission request is transmitted using the set parameter. The method of claim 16,
The parameter setting unit is configured to use an aperiodic SRS bandwidth corresponding to an I _MCS (Modulation and Coding Scheme index) corresponding to the terminal for aperiodic SRS reception, and transmits an I _MCS corresponding to the terminal to the terminal. Base station characterized in that. The method of claim 16,
The parameter setting unit is configured to use a Comb value corresponding to the Cyclic Shift Indicator (CSI) corresponding to the terminal for aperiodic SRS reception, and transmits the CSI corresponding to the terminal to the terminal. The method of claim 16,
The parameter setting unit is configured to use the number of transmit antenna ports corresponding to the cyclic shift indicator (CSI) corresponding to the terminal for aperiodic SRS reception, and to transmit the CSI corresponding to the terminal to the terminal . The method of claim 16,
The parameter required for the SRS transmission includes an aperiodic SRS bandwidth (BW),
An aperiodic SRS bandwidth is set to any one of the cell-specific periodic SRS bandwidth (cell specific).

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