KR101667264B1 - Method and apparatus for transmitting aperiodic srs(sounding reference signal) - Google Patents

Abstract

The present invention relates to an aperiodic SRS transmission method, wherein an aperiodic SRS transmission method of a terminal according to an embodiment of the present invention includes receiving an aperiodic SRS transmission request from a base station via a PDCCH, Receiving parameter information necessary for non-periodic SRS transmission using at least one of PDCCH and RRC signaling from the BS, parameter setting for setting parameters necessary for SRS transmission using the received parameter information And transmitting the aperiodic SRS to the BS in the corresponding subframe in which the UE receives the aperiodic SRS transmission request using the set parameters.

Description

Technical Field [0001] The present invention relates to a method and apparatus for transmitting an SRS,

[0001] The present invention relates to an aperiodic SRS (Sounding Reference Signal) transmission method and apparatus, and more particularly, to a transmission method of an aperiodic SRS in which an aperiodic SRS transmission bandwidth, transmission time, transmission parameters such as an antenna used and a cyclic shift The method comprising

In a long term evolution (LTE) system, terminals periodically transmit a sounding reference signal (SRS), and the base station uses periodic SRS information of each terminal to transmit uplink channel state And then schedules frequency resources to be used in the uplink and a Modulation and Coding Scheme (MCS) to each mobile station. In order for the UE to transmit periodic SRS information, the BS periodically informs the UE of periodic SRS BW (Bandwidth) information that is differently set according to the cell and UE specific ) Information such as periodic SRS BW, a transmission start position in a frequency resource, a cyclic shift (CS), and a transmission comb (Comb) is informed through RRC (Radio Resource Control) signaling. The UE sets parameters for periodic SRS transmission using such information, and transmits a periodic SRS in the corresponding subframe.

In the LTE-A (LTE-Advanced) system, the use of multiple transmit and receive antennas in the uplink introduces a periodic SRS transmission and aperiodic SRS transmission. However, there is a solution regarding whether the base station informs the UE of the parameters necessary for aperiodic SRS transmission and whether it can perform aperiodic SRS transmission without colliding with existing periodic SRS transmission resources Is required.

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

In order to achieve the above object, an aperiodic SRS (Sounding Reference Signal) transmission method of a UE according to an embodiment of the present invention is characterized in that the UE transmits a Physical Downlink Control Channel (PDCCH) Receiving an aperiodic SRS transmission request from the base station, receiving the parameter information necessary for the aperiodic SRS transmission using at least one of PDCCH and Radio Resource Control (RRC) signaling from the base station, A parameter setting step of setting parameters required for SRS transmission using the received parameter information by the terminal and a parameter setting step of setting an aperiodic SRS in a corresponding subframe in which the terminal receives an aperiodic SRS transmission request using the set parameters, As shown in FIG.

In order to achieve the above object, an aperiodic SRS (Sounding Reference Signal) reception method of a base station (eNB) according to an embodiment of the present invention is a method in which a base station transmits a Physical Downlink Control Channel (PDCCH) A parameter setting step of setting a parameter required for SRS transmission of the UE, and a step of setting a parameter by using at least one of PDCCH and RRC (Radio Resource Control) signaling to the UE Transmitting the parameter information of the set parameter, and receiving the aperiodic SRS from the terminal in the corresponding subframe in which the base station receives the aperiodic SRS transmission request using the set parameters.

In order to achieve the above-mentioned object, a UE transmitting an aperiodic SRS according to an embodiment of the present invention transmits a Physical Downlink Control Channel (PDCCH) from a base station (eNB) Receiving an aperiodic SRS transmission request, receiving parameter information necessary for non-periodic SRS transmission using at least one of PDCCH and Radio Resource Control (RRC) signaling from the base station, and transmitting SRS using the received parameter information And a transmission antenna for transmitting the aperiodic SRS to the BS in the corresponding subframe in which the UE transmits the aperiodic SRS transmission request using the set parameters.

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

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

According to an embodiment of the present invention, there is an effect that periodic SRSs and aperiodic SRSs transmitted by other terminals do not collide with each other. Also, according to an embodiment of the present invention, an increase in PDCCH (Physical Downlink Control Channel) control information is prevented.

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

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings and drawings. In the following description, 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. The following terms are defined in consideration of the functions of the present invention, and these may be changed according to the intention of the user, the operator, or the like. Therefore, the definition should be based on the contents throughout this specification.

In particular, in describing embodiments of the present invention, a wireless communication system based on OFDM (Orthogonal Frequency Division Multiplexing), in particular a 3GPP EUTRA (or LTE) or Advanced E-UTRA (or LTE-A) It is to be understood that the subject matter of the present invention is also applicable to other communication systems having similar technical background and channel form with slight modifications within the scope of the present invention without departing from the scope of the present invention, Will be possible at the discretion of the person skilled in the art.

In the LTE-Advanced system, in order to transmit an aperiodic SRS, a terminal selectively sets information necessary for aperiodic SRS transmission by selectively using RRC signaling and Physical Downlink Control Channel (PDCCH) information from a base station Lt; / RTI > That is, the UE may set parameters related to aperiodic SRS transmission through RRC signaling from the base station, and the UE may implicitly or implicitly transmit parameters related to aperiodic SRS transmission through the PDCCH from the base station You can set it explicitly. Also, the UE can set parameters necessary for SRS transmission by selectively using the RRC signaling and the PDCCH from the base station. In one embodiment, aperiodic SRS bandwidth (BW) can be implicitly set using Modulation and Coding Scheme (MCS) information (i.e., I _MCS ) of the PDCCH for aperiodic SRS transmission , Where the aperiodic SRS BW may be set among periodic SRS BWs that are cell specific.

Although the following embodiments individually describe the setting of aperiodic SRS transmission parameters, all parameters necessary for aperiodic SRS transmission are set simultaneously by RRC signaling and PDCCH control information, or some of the parameters Can be selectively set.

≪ Example 1 >

In the first exemplary embodiment, for the aperiodic SRS transmission, the UE selectively uses the RRC signaling information and the PDCCH information for aperiodic SRS transmission received from the base station to set a parameter for aperiodic SRS transmission Describe the process.

1 is a flow chart of a process of setting a parameter of a UE for UE transmission according to the first embodiment of the present invention.

Referring to FIG. 1, a UE is allocated 101 necessary parameters for aperiodic SRS transmission using RRC signaling from a base station. The UE receives a request for aperiodic SRS transmission by a PDCCH (UL Grant or DL Grant) from the BS, and simultaneously receives the parameters explicitly or implicitly allocated (102). In this case, when explicitly allocated, it implies that a resource (bit for control information) is assigned to inform the UL grant (or DL grant) of the parameters necessary for aperiodic SRS transmission do. On the contrary, in the case of being implicitly allocated, resources for parameters necessary for aperiodic SRS transmission are not allocated to UL grants (or DL grants), but specific parameter information of UL grants (or DL grants) I _MCS ) and information related to aperiodic SRS transmissions (e.g., aperiodic SRS BW). The UE may use the aperiodic RRC signaling and the PDCCH information to select parameters necessary for aperiodic SRS transmission (e.g., SRS BW, frequency-domain starting position, number of transmit antennas, cyclic shift (CS) And Comb (103). The UE transmits an aperiodic SRS in a corresponding subframe, i.e., a subframe requested to transmit an aperiodic SRS according to a set value (104).

2 is a flowchart of a parameter setting process of a base station (eNB) for aperiodic SRS transmission according to the first embodiment of the present invention.

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

3 is a block diagram of a UE for aperiodic SRS transmission according to the first embodiment of the present invention.

Referring to FIG. 3, the UE parameter setting unit 301 sets parameters required for aperiodic SRS transmission through the RRC signaling and the PDCCH from the base station, as described with reference to FIG. 1 and FIG. The sequence generator 302 generates a sequence for an aperiodic SRS transmission signal using the parameters set by the parameter setting unit 301. The frequency resource allocation unit 303 allocates a bandwidth and a start position for an aperiodic SRS transmission using the parameters set by the parameter setting unit 301. [ The IFFT unit 304 then performs IFFT (Inverse Fast Fourier Transform) on the aperiodic SRS signal. The IFFT-processed aperiodic SRS signal is transmitted through the transmission antenna 305 according to the parameter set in the parameter setting unit 301. [

4 is a block diagram of a base station for aperiodic SRS reception according to the first embodiment of the present invention. Referring to FIG. 4, the base station parameter setting unit 401 sets parameters for aperiodic SRS reception of each mobile station, and transmits the RRC signaling and the PDCCH, as described with reference to FIGS. 1 and 2, And transmits parameters necessary for aperiodic SRS transmission to the UE. 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. The SRS information demultiplexing unit 404 then separates the information from the aperiodic SRS of each UE from the aperiodic SRS signal that is DFTed using the parameters set by the base station parameter setting unit 401. [ The scheduling unit 405 estimates channel state information between the corresponding UE and the base station based on the information of the aperiodic SRS using the parameters set by the base station parameter setting unit 401, Scheduling.

(Aperiodic SRS BW), a frequency domain starting position (CS), a cyclic SRS frequency band (CS), a cyclic SRS frequency band Shift) and Comb, and the number of antennas.

≪ Example 2 >

Aperiodic SRS BW

For aperiodic SRS transmission, the base station must allocate an aperiodic SRS BW for each UE and each UE shall set it to use its assigned aperiodic SRS BW. For this purpose, a method for transmitting information about an aperiodic SRS BW to a UE includes (1) implicitly associating with I _MCS , (2) using a periodic SRS BW, (3) a method of using RRC signaling for aperiodic SRS transmission, and the like.

A. I _MCS To suggest implicitly an aperiodic SRS BW using

The UL grant (or DL grant) of the PDCCH includes control information necessary for transmission of an uplink or downlink data channel. Of these control information, Modulation and Coding Scheme (MCS) can indicate information about modulation and coding of a data channel to be transmitted and is expressed by I _MCS . In general, the higher the MCS, the better the channel state, and the lower the MCS the worse the channel state. The present invention suggests implicitly indicating an aperiodic SRS BW using the I _MCS of the PDCCH. That is to say, 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 possible to determine what to select as aperiodic SRS BW using the I _MCS information of the PDCCH Implicitly indicated. The advantage of such an implicit method is that it does not require the addition of additional control information fields in the corresponding PDCCH and therefore does not increase the overhead of the PDCCH. The present invention assumes the use of I _MCS as an example where an aperiodic SRS BW is implicitly indicated using the PDCCH control information field. However, in addition to I _MCS, there are various control information parameters (e.g., precoding matrix index (PMI), cyclic shift indicator (CSI)) in the PDCCH, implicitly indicating an aperiodic SRS BW, It should be noted that the embodiments using fields are not excluded.

The aperiodic SRS BW can 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. , The periodic SRS BW and the aperiodic SRS BW have the following correspondence.

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

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

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

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

The reason why cell-specific periodic SRS BWs are used as aperiodic SRS BWs is because of the collision between BWs during periodic SRS transmission and aperiodic SRS transmission. To prevent.

The specific methods for informing the aperiodic SRS BW with I _MCS are as follows. Here, the I _MCS of the UL grant is used as an example, but the same method can also be used for the DL grant.

A-1

The first is to set the aperiodic SRS BW according to the modulation order of the I _MCS . As shown in Table 1, from I _MCS 21 to I _MCS 28 with 64QAM modulation is assigned the largest aperiodic SRS BW, and from 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. In this method, the modulation order and the size of the BW may be allocated differently. For example, if 64QAM is allocated the largest aperiodic SRS BW, it may allocate the second largest aperiodic SRS BW 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 < RTI ID = 0.0 > 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 way is to indicate the aperiodic SRS BW according to the range of I _MCS . The largest largest aperiodic SRS BW is assigned to I _MCS from 21 to 28, and the second largest non-periodic _MCS is assigned to I _MCS between 14 and 20, as shown in Table 2 allocate the aperiodic SRS BW, allocate the third largest I- _MCS from 7 to 13 to the aperiodic SRS BW, and assign the smallest I _MCS between 0 and 6 ) Allocates 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 < RTI ID = 0.0 > 21-28 The largest aperiodic SRS BW

If we want to use only the two largest aperiodic SRS BWs, we indicate the largest aperiodic SRS BW when I _MCS is between 14 and 28, as shown in Table 3, and I _And the second largest aperiodic SRS BW when the _MCS is between 0 and 13.

MCS Index
I _MCS Allocated aperiodic SRS BW 0-13 The second largest aperiodic SRS BW < RTI ID = 0.0 > 14-28 The largest aperiodic SRS BW

A-3

A third way is to indicate an aperiodic SRS BW according to the group of I _MCS . The values of I _MCS are grouped as shown in Table 4 to assign the largest aperiodic SRS BW to 3, 7, 11, 15, 19, 23, 27 and 2, 6, 10, 14 , The second largest aperiodic SRS BW to 18, 22 and 26 and the third largest to 1, 5, 9, 13, 17, 21, Allocate an aperiodic SRS BW and allocate the smallest aperiodic SRS BW to 0, 4, 8, 12, 16, 20, 24, Thus, the method of indicating an aperiodic SRS BW according to a group of I _MCS increases the flexibility of selecting an aperiodic SRS BW, and the MCS for transmission of UL data is also appropriately You 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 < RTI ID = 0.0 > 3,7,11,15,19,23,27 The largest aperiodic SRS BW

If only the two largest aperiodic SRS BWs are to be used, the I _MCS , which is even (eg, 0, 2, 4, 6, ..., 28) the largest largest aperiodic SRS BW and I _MCSs with odd numbers (eg 1, 3, 5, 7, ...., 27) are assigned the second largest aperiodic ) SRS BW is allocated.

MCS Index
I _MCS Allocated aperiodic SRS BW Odd values
(1, 3, ..., 27) The second largest aperiodic SRS BW < RTI ID = 0.0 > Even values (0, 2, 4, ..., 28) The largest aperiodic SRS BW

Contrary to Table 5, it is possible to allocate the largest aperiodic SRS BW to an I _{MCS that} is an odd number (e.g., 1, 3, 5, 7, ..., 27) It is also possible to set the second largest aperiodic SRS BW in the I _MCS , which is 2, 4, 6, ..., 28.

5 is a flowchart of an aperiodic SRS transmission process according to the second embodiment of the present invention.

First, the UE acquires control information values necessary for UL or DL transmission from the BS 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. If there is an aperiodic SRS transmission request, it checks whether the I _MCS value is an odd number or an even number (503). If the I _MCS value is even, set the largest aperiodic SRS BW to be used (504) and transmit an aperiodic SRS in the corresponding subframe (506). If the I _MCS value is odd, the second highest aperiodic SRS BW is used (505) and an aperiodic SRS is transmitted in the corresponding sub-frame (507). As described above, aperiodic SRS BWs can be selected from configured cell-specific periodic SRS BWs. So far, we have described how the I _MCS in the PDCCH implicitly indicates to establish an aperiodic SRS BW.

B. Using periodic SRS BW

The periodic SRS BW can be used equally to set the BW for aperiodic SRS transmissions. That is, the UE uses the same BW in periodic SRS transmission and aperiodic SRS transmission. For this, information about the periodic SRS BW is informed to the UE before an aperiodic SRS transmission.

C. Provide aperiodic SRS BW information using RRC signaling

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

≪ Example 3 >

Frequency Domain Starting Position

In order for a UE to transmit an aperiodic SRS, the UE must know at which point of the frequency the aperiodic SRS starts. (1) RRC usage, (2) explicit notification through PDCCH, and (3) reuse of frequency domain starting position for periodic SRS transmission. This is possible.

A. Using RRC

The base station directly notifies the UE of the starting position in the frequency domain for aperiodic SRS transmission using RRC signaling.

B. Explicitly notify PDCCH

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

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

The starting position in the frequency domain for aperiodic SRS transmission is made equal to the starting position in the frequency domain for periodic SRS transmission. For this purpose, before the UE performs aperiodic SRS transmission, the Node B notifies the UE of the start position in the frequency domain for periodic SRS transmission.

<Example 4>

CS (Cyclic Shift) and Comb

(1) a method of implicitly instructing a CS and a comb value using CSI (Cyclic Shift Indicator) as a method of informing a UE of a CS value and a corresponding Comb value for an aperiodic SRS transmission of a UE to a UE, (2) how to use RRC, (3) how to explicitly inform using PDCCH, and (4) reuse of CS and Comb used in periodic SRS.

A. Implicitly indicating CS and Comb values using CSI

In the UL grant of the PDCCH, there is a control information field called CSI (Cyclic Shift Indicator). The original purpose is to inform the CS value for DM-RS (DeModulation Reference Signal) generation required for UL data transmission. In the present invention, a method of implicitly setting a CS value and a Comb value for aperiodic SRS transmission using a CSI value used for DM-RS is proposed. Here, Comb is a parameter indicating whether to transmit only the even-numbered subcarriers or only the odd-numbered subcarriers in the 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 so as to prevent collision with the periodic SRS resource.

As shown in Table 6, there are 8 CSI values, and CS and Comb are implicitly set 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 can be set equal to the CSI value. If the CSI value is an even number, 0 &quot; when the CSI value is an odd number.

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 UE uses multiple antenna ports (for example, four antenna ports), four CS values are required for aperiodic SRS transmission, The CS value and the Comb value for the aperiodic SRS can 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, and according to CSI values as shown in Table 8 The CS value and the Comb value for the aperiodic SRS can 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

6 is a flowchart illustrating a process of setting a CS value and a Comb value necessary for an aperiodic SRS transmission using a CSI value of an UL grant by a UE. First, the UE acquires control information values necessary for UL data transmission from the BS through the PDCCH (601). (602) whether there is an aperiodic SRS transmission request from the PDCCH control information field. If there is no aperiodic SRS transmission request, the UE waits for the next PDCCH reception. If there is an aperiodic SRS transmission request, it implicitly sets CS and Comb according to the CSI value in the PDCCH (603) And transmits an aperiodic SRS in the frame (604).

B. Using RRC

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

C. Explicitly informed using PDCCH

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

D. CS and Comb reuse in periodic SRS

Reuse CS and Comb values used for periodic SRS transmissions for aperiodic SRS transmissions. For this purpose, before the UE performs aperiodic SRS transmission, CS and Comb information used for periodic SRS transmission should be informed to the UE.

&Lt; Example 5 >

Number of transmit antennas

(1) a method of implicitly designating the number of transmit antenna ports using CSI, (2) a method of explicitly specifying the number of transmit antenna ports to be used for aperiodic SRS transmission of the UE, (3) using the RRC, and so on.

A. Indicate the number of transmit antenna ports implicitly using CSI

The UE can implicitly set whether to transmit an aperiodic SRS in one transmit antenna mode or an aperiodic SRS in a multiple transmit antenna mode by using the CSI control information of the PDCCH. As shown in Table 9, when CSI is 0, 1, 4, and 5, four CS values are given. Therefore, aperiodic SRS should be transmitted to four transmit antenna ports. If CSI is 2, 3, 6, 7, one CS value is given, so 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, in the case of CSI = 0, 1, 4, and 5, since two CS values are given, aperiodic SRS should be transmitted at two transmit antenna ports. If CSI is 2, 3, 6, 7, one CS value is given, so one aperiodic SRS should be transmitted at one transmit 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 a CS value, a comb value, and a number of transmit antenna ports required for an aperiodic SRS transmission using a CSI value of an UL grant by a UE. First, the UE acquires control information values necessary for UL data transmission from the BS through the PDCCH (701). PDCCH control information field (step 702). If there is no aperiodic SRS transmission request, the UE waits for the next PDCCH reception. If there is an aperiodic SRS transmission request, CS and the DRCP value 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 set number of CSs (703), and an aperiodic SRS is transmitted in the corresponding subframe (704).

B. Explicitly using PDCCH

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

C. RRC

The base station sets whether to transmit aperiodic SRS to one or more antenna modes by using RRC signaling.

At this point, it will be appreciated that the combinations of blocks and flowchart illustrations in the process flow diagrams may be performed by computer program instructions. These computer program instructions may be loaded into a processor of a general purpose computer, special purpose computer, or other programmable data processing apparatus, so that those instructions, which are executed through a processor of a computer or other programmable data processing apparatus, Thereby creating means for performing functions. These computer program instructions may also be stored in a computer usable or computer readable memory capable of directing a computer or other programmable data processing apparatus to implement the functionality in a particular manner so that the computer usable or computer readable memory The instructions stored in the block diagram (s) are also capable of producing manufacturing items containing instruction means for performing the functions described in the flowchart block (s). Computer program instructions may also be stored on a computer or other programmable data processing equipment so that a series of operating steps may be performed on a computer or other programmable data processing equipment to create a computer- It is also possible for the instructions to perform the processing equipment to provide steps for executing the functions described in the flowchart block (s).

In addition, each block may represent a module, segment, or portion of code that includes one or more executable instructions for executing the specified logical function (s). It should also be noted that in some alternative implementations, the functions mentioned in the blocks may occur out of order. For example, two blocks shown in succession may actually be executed substantially concurrently, or the blocks may sometimes be performed in reverse order according to 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, 'part' 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, by way of example, 'parts' may refer to components such as software components, object-oriented software components, class components and task components, and processes, functions, , Subroutines, segments of program code, drivers, firmware, microcode, circuitry, data, databases, data structures, tables, arrays, and variables. The functions provided in the components and components may be further combined with a smaller number of components and components or further components and components. In addition, the components and components may be implemented to play back one or more CPUs in a device or a secure multimedia card.

It will be understood by those skilled in the art that the present invention may be embodied in other specific forms without departing from the spirit or essential characteristics thereof. 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 defined by the appended claims rather than the foregoing detailed description, and all changes or modifications derived from the meaning and range of the claims and the equivalents thereof are included in the scope of the present invention Should be interpreted.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is to be understood that the invention is not limited to the disclosed embodiments, but, on the contrary, And is not intended to limit the scope of the invention. It is to be understood by those skilled in the art that other modifications based on the technical idea of the present invention are possible in addition to the embodiments disclosed herein.

Claims (20)

A signal transmission method of a terminal (UE)
Receiving an aperiodic SRS (Sounding Reference Signal) transmission request from a base station (eNB) through a Physical Downlink Control Channel (PDCCH);
Receiving at least one parameter setting information for setting a parameter required for aperiodic SRS transmission using at least one of PDCCH and Radio Resource Control (RRC) signaling from the base station;
A parameter setting step of setting parameters required for aperiodic SRS transmission using the at least one parameter setting information received by the terminal; And
And transmitting the aperiodic SRS to the BS in the corresponding subframe in which the UE receives the aperiodic SRS transmission request using the set parameters. The method according to claim 1,
Wherein the information receiving step includes the step of the terminal receiving an index of Modulation and Coding Scheme (I _MCS ) from the base station,
Wherein the parameter setting step includes setting an aperiodic SRS bandwidth corresponding to the received I _MCS to be used for aperiodic SRS transmission. The method according to claim 1,
Wherein the information reception step includes the step of the CSI (Cyclic Shift Indicator) from the base station,
Wherein the parameter setting step comprises setting a Comb value corresponding to the received CSI to be used for aperiodic SRS transmission. The method according to claim 1,
Wherein the information reception step includes the step of the CSI (Cyclic Shift Indicator) from the base station,
Wherein 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 according to claim 1,
The parameters required for the SRS transmission include an aperiodic SRS bandwidth (BW)
Wherein the aperiodic SRS bandwidth is set to any one of periodic SRS bandwidths that are cell specific. A signal reception method of a base station (eNB)
The base station transmitting an aperiodic SRS transmission request to the UE through a Physical Downlink Control Channel (PDCCH);
Setting parameters necessary for aperiodic SRS transmission of the terminal;
An information transmission step of transmitting, by the base station, at least one parameter setting information for causing the terminal to set parameters necessary for aperiodic SRS transmission, using at least one of PDCCH and Radio Resource Control (RRC) signaling; And
And receiving the aperiodic SRS from the terminal in the corresponding subframe in which the base station receives the aperiodic SRS transmission request using the set parameters. The method according to claim 6,
The parameter setting step includes the step of the base station to use an aperiodic SRS bandwidth corresponding to an I _MCS (Index of Modulation and Coding Scheme) corresponding to the terminal to receive aperiodic SRS,
And the information transmission step includes the base station transmitting an I _MCS corresponding to the terminal to the terminal. The method according to claim 6,
The parameter setting step may include setting a Comb value corresponding to CSI (Cyclic Shift Indicator) corresponding to the UE to be used for aperiodic SRS reception,
Wherein the information transmission step comprises the step of the base station transmitting a CSI corresponding to the terminal to the terminal. The method according to claim 6,
Wherein the parameter setting step includes setting a number of transmit antenna ports corresponding to CSI (Cyclic Shift Indicator) corresponding to the UE to be used for aperiodic SRS reception,
Wherein the information transmission step comprises the step of the base station transmitting a CSI corresponding to the terminal to the terminal. The method according to claim 6,
The parameters required for the SRS transmission include an aperiodic SRS bandwidth (BW)
Wherein the aperiodic SRS bandwidth is set to a periodic SRS bandwidth that is cell specific. In the terminal UE,
Receives an aperiodic SRS (Sounding Reference Signal) transmission request from a base station (eNB) through a Physical Downlink Control Channel (PDCCH), and uses at least one of PDCCH and RRC (Radio Resource Control) signaling from the base station A terminal parameter setting unit for receiving at least one parameter setting information for setting a parameter required for aperiodic SRS transmission and setting a parameter required for aperiodic SRS transmission using the received at least one parameter setting information; And
And a transmission antenna for transmitting an aperiodic SRS to the base station in a corresponding subframe in which the UE transmits an aperiodic SRS transmission request using the set parameters. 12. The method of claim 11,
The terminal parameter setting unit receives an I _MCS (Index of Modulation and Coding Scheme) from the base station,
And setting a non-periodic SRS bandwidth corresponding to the received I _MCS to be used for non-periodic SRS transmission. 12. The method of claim 11,
The terminal parameter setting unit receives CSI (Cyclic Shift Indicator) from the base station,
And a frequency resource allocation unit configured to use a Comb value corresponding to the received CSI for non-periodic SRS transmission. 12. The method of claim 11,
Wherein the terminal parameter setting unit receives CSI (Cyclic Shift Indicator) from the base station and sets the number of transmit antenna ports corresponding to the received CSI to be used for non-periodic SRS transmission. 12. The method of claim 11,
The parameters required for the SRS transmission include an aperiodic SRS bandwidth (BW)
Wherein the aperiodic SRS bandwidth is set to any one of cell-specific periodic SRS bandwidths. In the base station eNB,
An SRS (Sounding Reference Signal) transmission request is transmitted to the UE through a Physical Downlink Control Channel (PDCCH), a parameter required for the aperiodic SRS transmission of the UE is set, A base station parameter setting unit for transmitting at least one parameter setting information for setting parameters required for the aperiodic SRS transmission using at least one of PDCCH and Radio Resource Control (RRC) signaling; And
And a receive antenna for receiving an aperiodic SRS from the UE in a corresponding subframe in which an aperiodic SRS transmission request is transmitted using the set parameters. 17. The method of claim 16,
The parameter setting unit sets an aperiodic SRS bandwidth corresponding to an I _MCS (Index of Modulation and Coding Scheme) corresponding to the UE to be used for aperiodic SRS reception, and transmits an I _MCS corresponding to the UE to the UE . 17. The method of claim 16,
Wherein the parameter setting unit sets a Comb value corresponding to a CSI (Cyclic Shift Indicator) corresponding to the UE to be used for aperiodic SRS reception, and transmits the CSI corresponding to the UE to the UE. 17. The method of claim 16,
Wherein the parameter setting unit sets the number of transmit antenna ports corresponding to a CSI (Cyclic Shift Indicator) corresponding to the UE to be used for aperiodic SRS reception and transmits a CSI corresponding to the UE to the UE . 17. The method of claim 16,
The parameters required for the SRS transmission include an aperiodic SRS bandwidth (BW)
Wherein the aperiodic SRS bandwidth is set to any one of cell-specific periodic SRS bandwidths.

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