WO2012020936A2

WO2012020936A2 - Method and apparatus for transmitting and receiving aperiodic reference signal

Info

Publication number: WO2012020936A2
Application number: PCT/KR2011/005512
Authority: WO
Inventors: 김종남; 서성진
Original assignee: (주)팬택
Priority date: 2010-08-13
Filing date: 2011-07-26
Publication date: 2012-02-16
Also published as: WO2012020936A3

Abstract

The present invention relates to a method and apparatus for transmitting and receiving an aperiodic reference signal using downlink allocation. According to one embodiment of the present invention, a method for receiving the aperiodic reference signal comprises the steps of: allowing a reference signal reception device to set indication information indicating the aperiodic reference signal transmission of a reference signal transmission device in a first field for providing retransmission version information within the downlink allocation information, to set a value indicating transmission of new data in a second field, and to generate a wireless control signal including the downlink allocation information; transmitting the wireless control signal to the reference signal transmission device; and receiving the aperiodic reference signal from the reference signal transmission device.

Description

Method and apparatus for transmitting / receiving aperiodic reference signal

TECHNICAL FIELD The present disclosure relates to a wireless communication system, and more particularly, to a method and an apparatus for enabling a quick indication of aperiodic transmission of a reference signal for measuring or estimating a state of a resource in an OFDMA wireless communication system.

As communication systems have evolved, consumers, such as businesses and individuals, have used a wide variety of wireless terminals.

In the current mobile communication systems such as 3GPP, Long Term Evolution (LTE), LTE-A (LTE Advanced), etc., it is a high-speed, high-capacity communication system that can transmit and receive various data such as video and wireless data beyond voice-oriented services. Not only is the development of technology capable of transmitting large amounts of data comparable to wired communication networks, but also the proper error detection method to improve system performance by minimizing the reduction of information loss and increasing system transmission efficiency has become an essential element. .

In addition, many current communication systems use various signals to provide information on a communication environment to the counterpart device through uplink or downlink, and as an example of a signal, a reference signal (reference signal, or reference signal, RS) is used. Are being used.

For example, in an LTE system, which is one of mobile communication methods, a channel measurement or channel estimation reference signal indicating a channel state of a user equipment (hereinafter referred to as UE or UE) during uplink transmission. A sounding reference signal (SRS) is transmitted to the base station apparatus. Meanwhile, in order to identify channel information during downlink transmission, a cell-specific reference signal (CRS), which is the reference signal or the reference signal, is transmitted every subframe.

Meanwhile, the reference signals for measuring or estimating such a channel are periodically transmitted by the base station apparatus in the case of an uplink reference signal, that is, a base station apparatus in the case of an uplink reference signal and transmitted to the reference signal receiver. Is common.

Recently, however, a discussion has been made to transmit a channel estimation reference signal aperiodically due to flexibility of a communication system, but a specific method thereof has not been determined. In consideration of such a situation, in the current communication system, a specific transmission scheme for the aperiodic channel estimation reference signal is required.

An embodiment of the present disclosure provides a technique for transmitting and receiving a reference signal using downlink allocation in aperiodic transmission of the reference signal.

In addition, an embodiment of the present disclosure provides an aperiodic transmission technique of a reference signal for measuring or estimating a channel state of a terminal in a communication system.

In addition, an embodiment of the present specification provides a technique for enabling efficient use of resources by enabling aperiodic transmission of a reference signal through downlink allocation in a communication system, enabling resource allocation after channel information acquisition. do.

In addition, an embodiment of the present disclosure provides a technology that the indication information for controlling the transmission of the reference signal for aperiodic channel measurement can be delivered to the user terminal more quickly.

In a method for receiving an aperiodic reference signal according to an embodiment of the present invention for solving the above-described problems, the indication information indicating that the reference signal receiving apparatus instructs the transmission of the aperiodic reference signal of the reference signal transmitting apparatus is included in the downlink allocation information. Setting a first field to provide retransmission version information, a value indicating a transmission of new data to a second field, and generating a radio control signal including the downlink allocation information; Transmitting to the reference signal transmission device; And receiving an aperiodic reference signal from the reference signal transmitter.

According to another aspect of the present invention, there is provided a method of transmitting an aperiodic reference signal, the method comprising: receiving a radio control signal including downlink allocation information from a reference signal receiving apparatus, instructing transmission of new data in the downlink allocation information; And transmitting a non-periodic reference signal to the reference signal receiving apparatus when a value is set in the second field and the first field for providing retransmission version information is indication information for instructing aperiodic reference signal transmission. .

An aperiodic reference signal receiving apparatus according to another embodiment of the present invention includes an instruction information generation unit for generating indication information indicating the transmission of the aperiodic reference signal of the reference signal transmitting apparatus, and the retransmission version of the indication information in downlink allocation information. A coding unit for setting a first field for providing information, a value for indicating transmission of new data in a second field, and including the downlink allocation information in a physical control channel to generate a radio control signal, and And a transmitter / receiver for transmitting a radio control signal to the reference signal transmitter and receiving an aperiodic reference signal from the reference signal transmitter after the transmission.

In accordance with yet another aspect of the present invention, an aperiodic reference signal transmitting apparatus includes a transceiver for transmitting and receiving a signal to and from a reference signal receiving apparatus, a reference signal generator for generating a reference signal, and the transceiver assigning a downlink from the reference signal receiving apparatus. Receiving a radio control signal containing information, a value instructing transmission of new data in the downlink allocation information is set in the second field, and a first field providing retransmission version information is used for aperiodic reference signal transmission. And a control unit controlling the transceiver and the reference signal generator to transmit the aperiodic reference signal to the reference signal receiving device in the case of indicating indication information.

In a method for receiving an aperiodic reference signal according to another embodiment of the present invention, a retransmission version of downlink assignment information includes indication information indicating that the reference signal reception apparatus requires configuration information for aperiodic transmission of the reference signal transmission apparatus. Information is set in the Redundancy Version (RV) field providing information, a value indicating the transmission of new data is set in the New Data Indicator (NDI) field, and includes the downlink allocation information and is a PDCCH (Physical Downlink Control CHannel). Generating a radio control signal, transmitting the radio control signal to the reference signal transmission device, and receiving an aperiodic reference signal from the reference signal transmission device according to the setting information indicated by the indication information; The indication information is one or two bits in size, and one or more pieces of information necessary for transmitting the aperiodic reference signal are used. Characterized in that the information indicating the set containing the image.

A method of transmitting an aperiodic reference signal according to another embodiment of the present invention includes receiving a radio control signal including downlink allocation information and a physical downlink control channel (PDCCH) from a reference signal receiving apparatus, the downlink allocation If the value of the NDI (New Data Indicator) field in the information is a value indicating the transmission of new data, the indication information indicating the setting information required for aperiodic reference signal transmission is provided in a redundancy version (RV) field providing retransmission version information. And transmitting the aperiodic reference signal to the reference signal receiving apparatus according to the setting information indicated by the extracted indication information, wherein the indication information has a size of 1 or 2 bits. Characterized in that the information indicating the set containing one or more information required for the transmission of the reference signal.

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

2 illustrates a subframe and time slot structure of transmission data applicable to an embodiment of the present invention, and a general structure of a time-slot according to an embodiment of the present invention.

3 illustrates an example of periodic SRS transmission in a communication system to which the present embodiment can be applied.

4 is a diagram illustrating an example of SRS frequency hopping.

5 is a diagram illustrating the structures of

DCI formats

0 and 1 including triggering information of aperiodic SRS.

FIG. 6 is a diagram illustrating a configuration for reusing and providing information on a specific field in a DCI format for triggering information of an aperiodic SRS according to one embodiment of the present specification.

FIG. 7 is a diagram illustrating a process of interpreting by a UE when the base station according to an embodiment of the present disclosure transmits triggering information of aperiodic SRS by reusing information of a specific field in a DCI format as shown in FIG. 6.

8 is a diagram illustrating a configuration for reusing and providing information on a specific field in a DCI format for triggering information of an aperiodic SRS according to another embodiment of the present specification.

9 is a diagram illustrating a process of reusing and providing information of a specific field in a DCI format for triggering information of an aperiodic SRS according to another embodiment of the present specification.

10 is a diagram illustrating a process of receiving a reference signal by the reference signal receiving apparatus according to an embodiment of the present specification.

11 is a diagram illustrating a process of transmitting aperiodic reference signal by the apparatus for transmitting a reference signal according to an embodiment of the present specification.

12 is a diagram illustrating a configuration of a reference signal receiving apparatus according to an embodiment of the present specification.

FIG. 13 is a diagram illustrating a configuration of a reference signal transmission apparatus according to an embodiment of the present specification.

Hereinafter, some embodiments of the present invention will be described in detail through 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 addition, in describing the present invention, when it is determined that the detailed description of the related well-known configuration or function may obscure the gist of the present invention, the detailed description thereof will be omitted.

Wireless communication systems are widely deployed to provide various communication services such as voice and packet data.

Referring to FIG. 1, a wireless communication system includes a user equipment (UE) 10 and a base station 20 (base station, BS, eNB). The terminal 10 and the base station 20 apply an extended channel-referenced reference signal generation technique as described in the following embodiments, which will be described in detail with reference to FIG. 3 or below.

Terminal 10 in the present specification is a generic concept that means a user terminal in wireless communication, WCDMA, UE (User Equipment) in LTE, HSPA, etc., as well as MS (Mobile Station), UT (User Terminal) in GSM ), SS (Subscriber Station), wireless device (wireless device), etc. should be interpreted as including the concept. Hereinafter, the terminal, the user terminal and the UE will be used interchangeably.

The base station 20 or cell generally refers to all devices, functions, or specific areas communicating with the terminal 10, and includes a Node-B, an evolved Node-B, and a BTS (Base). It may be called other terms such as Transceiver System, Access Point, Relay Node.

That is, in the present specification, the base station 20 or the cell should be interpreted in a comprehensive sense indicating some areas covered by the base station controller (BSC) in the CDMA, the NodeB of the WCDMA, and the like. It is meant to cover various coverage areas such as microcell, picocell, femtocell and relay node communication range.

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

There is no limitation on the multiple access scheme applied to the wireless communication system. Various multiple access techniques such as Code Division Multiple Access (CDMA), Time Division Multiple Access (TDMA), Frequency Division Multiple Access (FDMA), Orthogonal Frequency Division Multiple Access (OFDMA), OFDM-FDMA, OFDM-TDMA, OFDM-CDMA Can be used.

The uplink transmission and the downlink transmission may use a time division duplex (TDD) scheme that is transmitted using different times, or may use a frequency division duplex (FDD) scheme that is transmitted using different frequencies.

One embodiment of the present invention is resource allocation in the fields of asynchronous wireless communication evolving into Long Term Evolution (LTE) and LTE-advanced through GSM, WCDMA, HSPA, and synchronous wireless communication evolving into CDMA, CDMA-2000 and UMB. Can be applied to 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.

A wireless communication system to which an embodiment of the present invention is applied may support uplink and / or downlink HARQ, and may use a channel quality indicator (CQI) for link adaptation. In addition, multiple access schemes for downlink and uplink transmission may be different. For example, downlink uses Orthogonal Frequency Division Multiple Access (OFDMA), and uplink uses Single Carrier-Frequency Division Multiple Access (SC-FDMA). ) Is the same as can be used.

The layers of the radio interface protocol between the terminal and the network are based on the lower three layers of the Open System Interconnection (OSI) model, which are well known in communication systems. The physical layer may be divided into a second layer (L2) and a third layer (L3), and the physical layer belonging to the first layer provides an information transfer service using a physical channel.

One radioframe or radio frame may consist of 10 subframes 210, and one subframe may include two

slots

202 and 203. In general, the basic unit of data transmission is a subframe unit, and downlink or uplink scheduling is performed on a subframe basis.

One slot may include a plurality of OFDM symbols in the time domain and at least one subcarrier in the frequency domain (frequency band), and one slot may be seven (for Normal CP) or six (for Extended CP). It may include an OFDM symbol of. For example, if a subframe consists of two time slots, each time slot may include seven symbols in the time domain and twelve subcarriers or subcarriers in the frequency domain, such that time is defined as one slot. The frequency domain may be referred to as a resource block or a resource block (RB), but is not limited thereto.

In 3GPP LTE systems, the transmission time of a frame is divided into TTIs (transmission time intervals) of 1.0 ms duration. The terms "TTI" and "sub-frame" may be used in the same sense, and a radio frame or frame according to an embodiment of the present specification is 10 ms long and includes 10 TTIs. can do.

202 illustrates a general structure of a time-slot according to an embodiment of the present invention.

As described above, the TTI is a basic transmission unit, where one TTI includes two

time slots

202 and 203 of equal length, each time slot having a duration of 0.5 ms. Have

Time-slot 202 includes seven long blocks (LB) 211 for a symbol. LBs are separated into cyclic prefixes (CP) 212. Collectively, one TTI or subframe may include 14 LB symbols, but the present specification is not limited to such a frame, subframe or time-slot structure. As described above, the subframe may include six LB symbols, that is, 12 LB symbols per slot, and the number of such symbols may be variously increased or decreased according to the operation status of the network.

Meanwhile, in the LTE communication system, which is one of the current wireless communication methods, a demodulation reference signal (DMRS) and a sounding reference signal are defined in uplink.

Meanwhile, three reference signals are defined in the downlink, a cell specific reference signal (CRS), an MBSFN reference signal (Multicast / Broadcast over Single Frequency Network Reference Signal; MBSFN-RS), and a UE specific reference signal (UE-). specific reference signal).

That is, in a wireless communication system, the terminal transmits a reference signal for uplink channel estimation or measurement, which is a type of reference signal, to a single base station to transmit uplink channel information to the base station. An example of the channel estimation reference signal may be a sounding reference signal (SRS) used in LTE and LTE-Advanced, which has the same function as a pilot channel for an uplink channel.

In the following description, a process and method for controlling aperiodic transmission of a reference signal will be described. The reference signal means a signal transmitted between the terminal and the base station. An embodiment of the reference signal will be described based on a channel estimation reference signal and a sounding reference signal (SRS), which is an embodiment thereof. However, the present invention is not limited to a reference signal for SRS or channel estimation or channel measurement. It should be understood as a concept including all kinds of reference signals used in a link or a downlink.

Such SRS should be able to deliver uplink channel information for all bands including not only the band used by each UE but also the band available to the UE to the base station. In other words, the SRS needs to be transmitted over the entire subcarrier band.

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]

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 0 to 7, and is set for each UE by signaling through a higher layer such as RRC (Radio Resource Control).

Table 1

The transmission subframe of the periodic sounding reference signal (Periodic SRS) is determined by srsSubframeConfig of Table 1. srs-SubframeConfig is a cell-specific parameter and is transmitted in a higher layer, and SRS transmission is possible in the last symbol of a subframe satisfying [Equation 2]. In Equation 2, T _SFC is a subframe configuration period.

Is an offset, and these may be determined as cell specific parameters or may be predetermined values according to srs-SubframeConfig. SRS transmission is possible on the last symbol of n _s that satisfies the above value. n _s is the index of the slot.

[Equation 2]

The base station informs each terminal of the transmission period and offset of the SRS through the SRS configuration index of Table 2, which is a UE-specific parameter. The transmission period is one of {2,5,10,20,40,80,160,320}, and the offset has the number of branches equal to the size of the transmission period for each transmission period. For example, when ISRS = 20, the transmission period is 20ms and the offset is 3ms.

TABLE 2

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 in each case, a transmission period and an actual transmission subframe offset are defined.

That is, when the srsSubframeConfiguration value is 8 (1000 in binary), this means that the SRS is transmitted in the second and third subframes every five subframes.

Referring to FIG. 3, as an example, when the srsSubframeConfiguration value is 8 (1000 in binary), a configuration of transmitting an SRS in second and third subframes every five subframes is illustrated.

Here, the SRS may be transmitted in the last symbol of each subframe. For example, when one subframe consists of 14 symbols (in the case of Normal Cyclic Prefix), when the SRS is transmitted in the 14th symbol, and consists of 12 symbols (in the case of Extended Cyclic Prefix), SRS is transmitted in the 12th symbol. Of course, the position of the symbol in which the SRS is transmitted herein is not limited thereto.

According to the SRS configuration shown in Table 1 and FIG. 3, the SRS is transmitted periodically (periodic) for each radio frame or transmission period for each cell (base station).

When srcSubframeConfiguration is 8 in Table 1, the configuration period is 5 subframes, and the transmission offsets are 2 and 3.

FIG. 3 shows a case in which an SRS can be transmitted in the last symbol of # 2 and # 3 subframes every five subframes.

The necessary items for setting bandwidth information in SRS transmission are as follows. Depending on the bandwidth of the system, it can be configured as follows.

[Table 3] 80RB <Bandwidth of entire system

Setting information for 100 RB

Table 4 6RB

The bandwidth of the entire system

Setting information for 40 RB

[Table 5] 40RB <Bandwidth of entire system

Setting information for 60 RB

[Table 6] 60RB <Bandwidth of entire system

Setting information for 80 RB

Tables 3, 4, 5, and 6 show SRS bandwidth (BW, BandWidth) configuration, and show two parameters for SRS transmission. The first is C _SRS which represents a SRS bandwidth configuration in a cell as a cell-specific parameter. One of the four SRS bandwidths determined by the C _SRS is selected for the UEs in the cell, and the size of the SRS bandwidth to be transmitted by the UE is determined through the B _SRS , which is a UE-specific parameter. C _SRS and B _SRS are parameters transmitted from higher layers and their values depend on the system bandwidth.

Looking more closely, the bandwidth of the entire system, BW is 80RB (Resource Block) <system BW

In case of 100RB (Resource Block), the setting in Table 3 can be used. C _SRS (SRS BW configuration parameter) is a cell-specific information determined per cell (cell-specific) is a 3-bit size parameter, B _SRS (SRS BW parameter) is information (UE-specific) set for each UE is a 2-bit parameter. Therefore, when C _SRS = 0 and B _SRS = 1, a user of a corresponding cell may have 48 RBs of the total 96 RBs as the SRS BW. Whether to transmit to the upper 48RB or the lower 48RB of the 96RB is determined by the SRS start position that comes down to the RRC signaling (signaling). The SRS start position consists of 5 bits, and each position can be represented by dividing the entire system BW into up to 24 pieces.

4 is a diagram illustrating an example of SRS frequency hopping. 40 <RB (resource block) as shown in Table 5

SRS hopping is shown when the system bandwidth is 60. When C _SRS = 2 and B _SRS = 2, the UE

Has the value of. The above values are used for frequency hopping and the SRS transmission bandwidth (

) Becomes 4RB. Figure 4 shows an example of the leap of SRS transmission on the frequency axis with the application of these values. The number on the left side of FIG. 4 means an RB index. m _{SRS, n} means the amount of bandwidth to send SRS when Bsrs = n.

In order to efficiently transmit various SRSs, a dynamic aperiodic SRS transmission is required. This enables efficient use of limited SRS resources by transmitting dynamic aperiodic SRS signals to a terminal having a large amount of data to transmit, and can increase transmission efficiency by using frequency selective scheduling. In the present specification, a process of transmitting an A-SRS triggering signal using downlink allocation is described. For downlink allocation, a new DCI format (Downlink Control Information format, DCI format) may be configured or a certain area of information may be reused or changed in the existing DCI format. In the case of DCI format 0 and DCI format 1, a new triggering region may be allocated as shown in FIG. 5.

5 is a diagram illustrating the structures of

DCI formats

0 and 1 including triggering information of aperiodic SRS. 510 shows that aperiodic SRS triggering information is included as in 515 in the configuration of DCI format 0. 520 shows that aperiodic SRS triggering information is included as in 525 in the configuration of DCI format 1A. 5 shows a case where a new field is added to indicate aperiodic SRS triggering.

The format 600 of FIG. 6 may be applied to the DCI formats 1 / 1A / 1B / 1D. In this case, there are fields of 1 bit of NDI (New Data Indicator) 610 and 2 bits of Redundancy Version (620). In downlink allocation, the NDI 610 is a 1-bit field indicating whether a transport block (TB) currently transmitted is new-transmission or re-transmission. 2-bit field that indicates information for combining in retransmission. If the NDI field 610 indicates a new transmission (NDI = 0), the RV field 620 may be used as information for A-SRS triggering as in the embodiment of the present specification. When the value of the NDI field 610 is 0, the information (information for combining at retransmission) that the RV field 620 intends to provide is information which is not referenced by the user terminal. Therefore, when the value of the NDI field is 0, when A-SRS triggering is required, that is, new transmission is performed, and when A-SRS triggering is required, A-SRS triggering information is included in the RV field 620 and provided to the UE. In this case, A-SRS triggering information can be provided without changing the existing DCI format and without increasing blind decoding. The format 600 of FIG. 6 may be applied to the DCI format 1 / 1A / 1B / 1D, and the size of N may vary according to each format.

That is, indication information indicating aperiodic reference signal transmission is set in the RV field providing retransmission version information in downlink allocation information, and a value indicating a transmission of new data, for example, a value such as 0, is set in the NDI field. When setting and transmitting the radio control signal including the downlink allocation information, the user terminal, even if the value of the NDI field in the received information instructs the transmission of new data, such as 0, the value of the RV field is promised in advance If the indication information is related to the transmission of the non-periodic reference signal, it may be determined that the transmission of the aperiodic indication information is triggered.

The UE checks the DCI format by receiving a Psychological Downlink Control Channel (PDCCH) transmitted by the base station (S710). The NDI field and the RV field described above with reference to FIG. 6 are identified in the DCI format (S720). That is, blind decoding of the PDCCH in the search space is performed to check the values in the DCI format.

If the NDI field is 0 (S730), if not 0, that is, in case of retransmission, the RV field is checked (S735). On the other hand, when the NDI field is 0, the RV field is checked, and when it is not '11', since it is not related to A-SRS triggering (S745), it performs another function in relation to the DCI format. On the other hand, if the RV field is checked and '11', this indicates A-SRS triggering. The A-SRS triggering is confirmed (S750), and then the A-SRS is transmitted at a frequency and time previously scheduled with the base station. (S760). That is, in FIG. 7, if 'NDI = 0' is confirmed as a new transmission, 'NDI = 1' means retransmission, and if 'NDI = 1', the UE is retransmission, and thus RD (Redundancy Version) value is incremental redundancy (IR). It is used as 'Combining' information. On the contrary, if 'NDI = 0', RV 2-bit can be confirmed as information for A-SRS triggering. That is, the UE recognizes A-SRS triggering information included in downlink allocation by sequentially or simultaneously recognizing NDI and RV values. The values of NDI and RV in FIG. 7 may be variously applied in the implementation process. That is, in the present specification, when the value of the NDI is 0 and the RV value is 11, the present invention is information indicating A-SRS triggering, and the value of each field may be variously set in the implementation process. That is, the meaning of the NDI value and the RV value can be determined as needed or according to what value is set and used in the network.

The format 800 of FIG. 8 may be applied to the DCI formats 2 / 2A / 2B. It can be applied when two or more transport blocks (TB, 802, 804) are included. 8 looks at the case of two TBs. There are fields of 1 bit of NDI (New Data Indicator) 810 and 2 bits of RV (Redundancy Version, 820) for TB 1 802, and 1 bit of NDI (New Data Indicator, 830) and RV (for TB 2 804). Redundancy Version (840) There is a 2 bit field. If at least one TB corresponds to a new transmission in each of the

NDIs

810 and 830 and the

RVs

820 and 840 for the two

TBs

802 and 804, the NDI value of the corresponding TB is 0 and the RV value is A. Can be set as SRS triggering information. That is, when TB 1 is a new transmission, since the value of the NDI field 810 is set to 0 and the information that the RV field 820 intends to provide (information for combining at retransmission) is not information referenced by the user terminal, If the A-SRS triggering information is included in the RV field 820 and provided to the UE, the A-SRS triggering information can be provided without changing the existing DCI format and without increasing blind decoding. Of course, when TB2 is a new transmission, the NDI 830 and the RV field 840 may also be used. Alternatively, when both TBs are new transmissions, the RV field for one or more TBs may be used as an information setting region for A-SRS triggering. That is, in a system using two or more TBs, since an NDI or RV field may be set for each TB, A-SRS triggering may be used using information previously set among these or information set for all TBs.

The format 800 of FIG. 8 may be applied to the DCI formats 2 / 2A / 2B, and the size of N may vary according to each format.

9 is a diagram illustrating a process of reusing and providing information of a specific field in a DCI format for triggering information of an aperiodic SRS according to another embodiment of the present specification. Unlike FIG. 7, FIG. 9 may be applied when a plurality of transport block information is included. 9 illustrates a process of sequentially checking A-SRS triggering information when two TBs are used. First, triggering information on A-SRS transmission is checked with respect to TB1, and when NDI (TB1) = 0 and RV (TB1) = 11, it is determined that A-SRS triggering is commanded. If TB1 is retransmission, check whether A-SRS triggering is performed on NDI and RV of TB2 in the same manner. Looking in more detail as follows.

The UE checks the DCI format by receiving the PDCCH transmitted by the base station (S910). The NDI field and the RV field for TB 1 described above with reference to FIG. 8 are identified in the DCI format (S915). That is, blind decoding of the PDCCH in the search space is performed to check the values in the DCI format.

If the NDI field is 0 (S920), if not 0, that is, in case of retransmission, the RV field is checked and combined (S925). In addition, a process of checking whether or not A-SRS triggering is performed on TB2 is performed. On the other hand, if the NDI field is 0, the RV field is checked (S930), and if it is not '11', since it is not related to A-SRS triggering (S935), a process of checking whether A-SRS is triggered on TB2 is performed. do.

On the other hand, by checking the RV field (S930), if it is '11', this indicates the A-SRS triggering, and confirms the A-SRS triggering (S940). After confirming, the A-SRS is transmitted at a frequency and time previously agreed with the base station (S990).

If the TB1 fails to confirm the A-SRS triggering, the process proceeds to S950. That is, the NDI field and the RV field for TB2 are checked (S950). If the NDI field is 0 (S960), if not 0, that is, in case of retransmission, the RV field is checked and combined (S965). On the other hand, if the NDI field is 0, the RV field is checked (S970), and if it is not '11', this is not related to A-SRS triggering and both TB1 and TB 2 do not indicate A-SRS triggering. On the other hand, if the RV field is checked (S970) and '11', this indicates A-SRS triggering and confirms A-SRS triggering (S980). After confirming, the A-SRS is transmitted at a frequency and time previously agreed with the base station (S990). NDI values and RV values in FIG. 9 may be variously applied in the implementation process. That is, in the present specification, when the value of the NDI is 0 and the RV value is 11, the present invention is information indicating A-SRS triggering, and the value of each field may be variously set in the implementation process.

In FIG. 9, the NDI and RV values are sequentially checked for TB1 and TB2, but the NDI and RV values may be checked at the same time or in a different order. In addition, the triggering indication information of the A-SRS may be included in both of the two or more TBs, not necessarily confirming the NDI and RV values of the A-SRS in only one TB.

In FIG. 7 and FIG. 9, a user terminal transmits an A-SRS, and parameters for A-SRS transmission may be divided into a cell-specific parameter and a UE-specific parameter. One embodiment of the present specification may transmit the RRC signaling signal.

Cell-specific parameters are srs-SubframeConfig described in Table 1, srs-BandwidthConfig (C _SRS ) of Tables 3, 4, 5, and 6, and UEs in the same cell use the same value. UE specific parameters include srs-Bandwidth (B _SRS ) of Tables 3, 4, 5, 6,

And, the frequency and hopping information (freqDomainPosition, srs-HoppingBandwidth, transmissionComb, srs-Timer) necessary for transmitting the SRS can be allocated as new information for the A-SRS. Here, the srs-Timer is used when the A-SRS signal is transmitted a predetermined number of times by one A-SRS triggering rather than an activation / deactivation signaling technique for A-SRS transmission.

Of course, when the value of the NDI is 0, it can be used as activation / deactivation information for A-SRS transmission using the RV value. For example, when the RV is '11', information for triggering A-SRS transmission is transmitted, and as a result, A-SRS is transmitted. When the NDI value is 0 and the RV is '10' in the received DCI format, transmission of the A-SRS may be stopped.

As described above, A-SRS triggering may be indicated by using 2 bits of the RV field. This is an embodiment of the present specification and means that a value of another field may be used without necessarily using 2 bits of the RV field. For example, four states can be indicated by adding a separate 2 bit to the DCI format. In this case, one state (1-state) is used for (No aperiodic SRS) indicating that no SRS is sent. The remaining three states may be indicated by a parameter set or set for configuring the A-SRS.

For example, looking at SRS triggering and parameter setting using two bits, it can be configured as shown in Table 7.

TABLE 7

In the configuration of Table 7, state 4 (state-4) indicates deactivation of A-SRS and other states (states 1, 2, and 3) can be used to indicate a set of parameters for three types of A-SRS transmission. have. In Table 7, the state information has a value of 1 to 4, and the information for transmitting the SRS is matched according to each state information. Therefore, even if the base station provides only the state information using two bits to the user terminal, the user terminal can check the information necessary for SRS transmission matching the corresponding state information. Information about this set is provided through RRC in advance, and using one of

state

1, 2, and 3 state information, which of the three sets of RRC parameters provided is used to indicate A-SRS transmission. can do. SRS parameters that can be set using RRC include bandwidth, frequency domain location, hopping band, comb information, cyclic shift, period, antenna number (SrsBandwidth, FrequencyDomainposition, SrsHoppoingBandith (if hopping is supported), transmissionComb, cyclic shift , duration (if multi-shot SRS is supported), number of antenna ports), and the like. A state indicating the set (pair) of parameters may be A-SRS indication information.

That is, according to the embodiments of the present specification, Aperiodic SRS triggering / configuration through DL grant may use 'NDI' and 'RV' included in the downlink allocation. In this case, the RV field may also be 2-bit and indicate A-SRS triggering in an implementation manner such as 2-bit newly added for the purpose of A-SRS triggering / configuration in DCI format 4. One embodiment of the present specification includes one-to-one mapping of each state of the RV field to each 2-bit state added to indicate A-SRS in DCI format 4. In this case, as in DCI format 4, 1-state of 4-states of the RV field may indicate 'No aperiodic SRS', and the remaining 3-states may indicate A-SRS configuration parameter set. . As shown in Table 8 below, the A-SRS configuration parameter set information to be transmitted to the RRC may be shared with the DCI format 4.

[Table 8] Use of each state when RV field is used for Aperiodic SRS triggering

In addition, the 3-state for A-SRS triggering of DCI format 4 may include A-SRS triggering / configuration information on multiple CCs. In this case, each state of the RV field may be used as indicated by each state of 2-bit added for A-SRS triggering of DCI format 4, and thus, multiple CCs may be used by using DL grant. A-SRS triggering is also possible. That is, by using the 2-bit of the RV field according to an embodiment of the present specification can be used in the same technique as 2bit added to DCI format 4 for A-SRS triggering can overcome the constraints of 1bit triggering.

10 is a diagram illustrating a process of receiving a reference signal by the reference signal receiving apparatus according to an embodiment of the present specification. 10 may be implemented in a base station, a relay, and the like, and may also be implemented in an apparatus for only receiving a reference signal combined with the base station or a relay.

First, the reference signal receiving apparatus sets indication information indicating aperiodic reference signal transmission of the reference signal transmitting apparatus in a first field of the downlink allocation information (S1010). Here, the first field is a field for providing retransmission version information and means the RV field described above. According to the foregoing, in order to indicate transmission of an aperiodic reference signal to the RV field, the downlink allocation information indicates transmission of new data, and more specifically, transmission of data is indicated through a second field. This means an NDI field. The indication includes triggering an aperiodic transmission of the reference signal. The first field and the second field, for example, the RV field and the NDI field may be located in one downlink allocation information as described with reference to FIG. 6 or 8.

In operation S1020, a radio control signal including the downlink allocation information is generated. One embodiment of the radio control signal means a PDCCH, and the downlink allocation information may be DCI format 1 / 1A / 1B / 1D or DCI format 2 / 2A / 2B. The radio control signal is transmitted to the reference signal transmitter (S1030). Thereafter, an aperiodic reference signal is received from the reference signal transmitter (S1040).

The indication information of S1010 triggers the transmission of the aperiodic reference signal, and the indication information for notifying the transmission stop of the transmitted aperiodic reference signal may be set in the first field. That is, after receiving the aperiodic reference signal, it is determined whether to stop receiving the aperiodic reference signal. This may determine whether the reception of the reference signal is sufficient, and if the number of A-SRS transmissions is included in the A-SRS triggering, reception of the reference signal is no longer necessary according to the corresponding information. Instructions indicating that the transmission of the aperiodic reference signal of the reference signal transmission device is stopped are set in the first field (S1050). As described above, the reference signal transmission apparatus transmits the aperiodic reference signal by setting the NDI value of the DCI format to indicate transmission of new data and setting the value of the RV field, which is the first field, to a predetermined value. Include information promised to stop. In operation S1060, a radio control signal including the downlink allocation information is generated. When the generated radio control signal is transmitted to the user terminal (S1070), the reference signal transmission device stops transmitting the aperiodic reference signal.

Here, the first field may include two or more. That is, when there are two or more transport blocks, the downlink allocation information may include information on two or more transport blocks, and the first field may be included in the information on each transport block.

Accordingly, any one of the first fields included in each transport block may be set to indicate transmission of the aperiodic reference signal. As described above with reference to FIG. 9, when the RS indicates a new transmission and at least one transport block having an RV field of '11', the reference signal transmission apparatus may identify the transmission of the aperiodic reference signal.

In the process of Figure 10 is a process of providing information indicating the transmission of the aperiodic reference signal. Accordingly, information on which frequency band and at what time the aperiodic reference signal is transmitted may be separately provided. That is, the reference signal receiving apparatus may transmit information necessary for transmitting the aperiodic reference signal to the reference signal transmitting apparatus using higher layer signaling. Of course, it is possible to specify the number of times to transmit the A-SRS by adjusting the value of the RV. For example, when the RV is 01, the SRS transmission may be instructed once in the case of 10, twice in the case of 10, and three times in the case of 11, and a different number of times may be set as necessary.

11 is a diagram illustrating a process of transmitting aperiodic reference signal by the apparatus for transmitting a reference signal according to an embodiment of the present specification. 11 may be implemented in a user terminal (UE), and may also be implemented in an apparatus only for transmitting a reference signal coupled to the user terminal (UE).

The reference signal transmission apparatus receives a radio control signal including downlink allocation information from the reference signal receiving apparatus (S1110). In operation S1120, it is determined whether the first field in the downlink allocation information is indication information indicating aperiodic reference signal transmission. When the first field is the indication information indicating the transmission of the aperiodic reference signal, the aperiodic reference signal is transmitted to the reference signal receiving apparatus (S1130). Here, the first field is a field for providing retransmission version information and means the RV field described above. According to the above description, the RV field includes information indicating transmission of an aperiodic reference signal. This means that the downlink allocation information indicates transmission of new data. It is indicated through a field, which means an NDI field. The indication includes triggering an aperiodic transmission of the reference signal. One embodiment of the radio control signal means a PDCCH, and the downlink allocation information may be DCI format 1 / 1A / 1B / 1D or DCI format 2 / 2A / 2B. The first field and the second field, for example, the RV field and the NDI field may be located in one downlink allocation information as described with reference to FIG. 6 or 8.

Thereafter, when the process of transmitting the aperiodic reference signal is performed, the indication information indicating to stop the transmission of the aperiodic reference signal may be received again. That is, after transmitting the aperiodic reference signal as in S1130, a radio control signal including downlink allocation information is received from the reference signal receiving apparatus (S1140). In addition, it is determined whether the first field in the downlink allocation information is indication information for instructing to stop aperiodic reference signal transmission (S1150), and the indication information for instructing that the first field in the downlink aperiodic transmission stops. If it is, the transmission of the aperiodic reference signal is stopped (S1160).

Therefore, any one of the first fields included in each of the transport blocks is set to indicate the transmission of the aperiodic reference signal so that the radio control signal can be received in step S1110 or S1140. As described above with reference to FIG. 9, when the RS indicates a new transmission and at least one transport block having an RV field of '11', the reference signal transmission apparatus may identify the transmission of the aperiodic reference signal.

In the process of FIG. 11, the aperiodic reference signal is transmitted by receiving information indicating transmission of the aperiodic reference signal. Therefore, information on which frequency band and at what time the aperiodic reference signal is transmitted may be separately received. That is, the apparatus for transmitting a reference signal may receive information necessary for transmitting the aperiodic reference signal from the apparatus for receiving a reference signal using higher layer signaling. Of course, it is possible to specify the number of times to transmit the A-SRS by adjusting the value of the RV. For example, when the RV is 01, the SRS transmission can be instructed once in the case of 10, twice in the case of 10, and three times in the case of 11, and can be set to another value as necessary.

12 is a diagram illustrating a configuration of a reference signal receiving apparatus according to an embodiment of the present specification. 12 may be implemented in a base station, a relay, and the like, and may also be implemented in an apparatus for only receiving a reference signal combined with the base station or a relay.

The overall configuration is composed of an instruction information generator 1210, a coding unit 1220, and a transceiver 1230. The instruction information generator 1210 generates instruction information for instructing aperiodic reference signal transmission of the reference signal transmission apparatus, and the coding unit 1220 sets the instruction information to the first field in the downlink allocation information and performs the downlink. Link assignment information is included in a physical control channel to generate a radio control signal. Here, the first field is a field for providing retransmission version information and means the RV field described above. According to the foregoing, in order to indicate transmission of an aperiodic reference signal to the RV field, the downlink allocation information indicates transmission of new data, and more specifically, transmission of data is indicated through a second field. This means an NDI field. The indication includes triggering an aperiodic transmission of the reference signal. One embodiment of the radio control signal means a PDCCH, and the downlink allocation information may be DCI format 1 / 1A / 1B / 1D or DCI format 2 / 2A / 2B. The first field and the second field, for example, the RV field and the NDI field may be located in one downlink allocation information as described with reference to FIG. 6 or 8.

The transceiver 1230 transmits the radio control signal to the reference signal transmitter, and receives the aperiodic reference signal from the reference signal transmitter after the transmission.

Therefore, any one of the first fields included in each transport block may be set to indicate transmission of the aperiodic reference signal. As described above with reference to FIG. 9, when the RS indicates a new transmission and at least one transport block having an RV field of '11', the reference signal transmission apparatus may identify the transmission of the aperiodic reference signal.

On the other hand, the indication information indicating the transmission stop of the transmitted aperiodic reference signal can be set. That is, after receiving the aperiodic reference signal, the instruction information generator 1210 generates instruction information for instructing to stop transmitting the aperiodic reference signal of the reference signal transmitter, and the coding unit 1220 The indication information is set in a first field of downlink assignment information and the downlink assignment information is included in a physical control channel to generate a radio control signal. The transceiver 1230 transmits the radio control signal to the reference signal transmitter, and the reference signal transmitter no longer transmits the aperiodic reference signal.

Meanwhile, the apparatus of FIG. 12 may separately provide information on which frequency band and at what time a non-periodic reference signal is to be transmitted. That is, the reference signal receiving apparatus may transmit information necessary for transmitting the aperiodic reference signal to the reference signal transmitting apparatus by using higher layer signaling. Such higher layer signaling may be performed through the transceiver 1230.

FIG. 13 is a diagram illustrating a configuration of a reference signal transmission apparatus according to an embodiment of the present specification. 13 may be implemented in a user terminal (UE), and may also be implemented in an apparatus for only transmitting a reference signal coupled to the user terminal (UE).

The configuration of the reference signal transmitting apparatus includes a controller 1310, a reference signal generator 1320, and a transceiver 1330. The transceiver 1330 transmits and receives a signal with a reference signal receiving apparatus, and the reference signal generator 1320 generates a reference signal.

In addition, the control unit 1310 controls the transceiver 1330 and the reference signal generator 1320. In detail, the transceiver 1330 includes a radio including downlink assignment information from the reference signal receiver. The transceiver 1330 receives a control signal and transmits the aperiodic reference signal to the reference signal receiving apparatus when the first field in the downlink allocation information is indication information for instructing aperiodic reference signal transmission. The reference signal generator 1320 may be controlled.

Here, the first field is a field for providing retransmission version information and means the RV field described above. According to the above description, the RV field includes information indicating transmission of an aperiodic reference signal. This means that the downlink allocation information indicates transmission of new data. It is indicated through a field, which means an NDI field. The indication includes triggering an aperiodic transmission of the reference signal. One embodiment of the radio control signal means a PDCCH, and the downlink allocation information may be DCI format 1 / 1A / 1B / 1D or DCI format 2 / 2A / 2B. The first field and the second field, for example, the RV field and the NDI field may be located in one downlink allocation information as described with reference to FIG. 6 or 8.

Thereafter, when the process of transmitting the aperiodic reference signal is performed, the indication information indicating to stop the transmission of the aperiodic reference signal may be received again.

That is, after the transceiver 1330 transmits the aperiodic reference signal, the radio receiver receives a radio control signal including downlink allocation information from the reference signal receiving apparatus, and the first field in the downlink allocation information is aperiodic. In case of the indication information indicating to stop transmitting the reference signal, the controller 1310 may control the transceiver 1330 and the reference signal generator 1320 to stop the transmission of the aperiodic reference signal. .

The apparatus of FIG. 13 is a process of receiving information indicating transmission of an aperiodic reference signal and transmitting an aperiodic reference signal. Therefore, information on which frequency band and at what time the aperiodic reference signal is transmitted may be separately received. That is, the apparatus for transmitting a reference signal may receive information necessary for transmitting the aperiodic reference signal from the apparatus for receiving a reference signal using higher layer signaling. This may be done in the transceiver 1330.

When a specific DCI format is used for aperiodic reference signal, for example, aperiodic SRS transmission, a downlink allocation and usage scheme is limited, and the degree of freedom is reduced. Of course, this does not effectively solve the difficulty of efficient SRS allocation when transmitting information about an aperiodic SRS by only uplink allocation.

On the other hand, if information necessary for transmitting the aperiodic reference signal is transmitted using a new field, many changes such as an increase in the blind decoding level according to the size change of the existing format are required. According to an embodiment of the present specification, by using the fields included in the existing downlink allocation (New data indicator Field, Redundancy Version Field), it is determined whether the retransmission is to transmit the A-SRS triggering information when the new transmission. Therefore, by reusing the fields in the existing downlink allocation can be applied to all DCI formats without changing the size of the DCI format. That is, signal transmission is generally applicable regardless of the downlink transmission mode. As a result, it is possible to effectively allocate resources after channel information acquisition, and to obtain fast channel information by reducing delay time for aperiodic SRS signal transmission. Third, in a time division duplex, aperiodic SRS may be used as downlink transmission information. Unnecessary uplink allocation can be prevented by sending an aperiodic SRS triggering signal through downlink allocation.

The above description is merely illustrative of the technical idea of the present invention, and those skilled in the art to which the present invention pertains may make various modifications and changes without departing from the essential characteristics of the present invention. Therefore, the embodiments disclosed in the present invention are not intended to limit the technical idea of the present invention but to describe 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.

CROSS-REFERENCE TO RELATED APPLICATIONCROSS-REFERENCE TO RELATED APPLICATION

This patent application is filed with the U.S. Patent Application No. 10-2010-0078540 filed in Korea on August 13, 2010 and the patent application No. 10-2011-0001895 filed in Korea on January 7, 2011. Priority is claimed under section (a) (35 USC § 119 (a)), all of which is incorporated by reference in this patent application. In addition, if this patent application claims priority for the same reason as above for a country other than the United States, all the contents thereof are incorporated into this patent application by reference.

Claims

The reference signal receiving apparatus sets the instruction information indicating the aperiodic reference signal transmission of the reference signal transmitting apparatus to the first field providing retransmission version information in the downlink allocation information, and sets a value indicating the transmission of the new data. Setting a field and generating a radio control signal including the downlink allocation information;

Transmitting the radio control signal to the reference signal transmission device; And

Receiving an aperiodic reference signal from the reference signal transmission device.
The method of claim 1,

After receiving the aperiodic reference signal

Instruction information indicating to stop aperiodic reference signal transmission of the reference signal transmission apparatus is set in the first field, a value indicating transmission of new data is set in the second field, and the downlink allocation information Generating a radio control signal comprising a; And

And transmitting the radio control signal to the user terminal.
The method of claim 1,

The downlink allocation information includes information on at least two transport blocks, and wherein the first field is included in the information on each transport block, respectively.
The method of claim 3, wherein

Generating the radio control signal further comprises setting the indication information in at least one of a first field for the two or more transport blocks.
The method of claim 1,

And transmitting a set including one or more information necessary for transmitting the aperiodic reference signal to the reference signal transmitting apparatus and state information indicating the set using higher layer signaling. How to receive.
Receiving a radio control signal including downlink allocation information from a reference signal receiving apparatus;

When a value indicating transmission of new data in the downlink allocation information is set in a second field and the first field providing retransmission version information is indication information indicating aperiodic reference signal transmission, an aperiodic reference signal Transmitting the aperiodic reference signal to the reference signal receiving apparatus.
The method of claim 6,

After transmitting the aperiodic reference signal

Receiving a radio control signal including downlink allocation information from the reference signal receiving apparatus;

The aperiodic reference signal when a value indicating transmission of new data in the downlink assignment information is set in the second field and the first field is indication information indicating to stop transmitting the aperiodic reference signal Stopping the transmission of the non-periodic reference signal.
The method of claim 6,

The downlink allocation information includes information on two or more transport blocks, and wherein the first field is included in the information on each transport block, respectively.
The method of claim 8,

The transmitting step

Transmitting the aperiodic reference signal when the indication information is included in at least one of the first fields for the two or more transport blocks.
The method of claim 6,

And receiving from the reference signal receiving apparatus a set including one or more pieces of information necessary for transmitting the aperiodic reference signal and state information indicating the set using higher layer signaling. How to send.
An instruction information generator configured to generate instruction information for instructing aperiodic reference signal transmission of the reference signal transmitter;

The indication information is set in a first field for providing retransmission version information in downlink allocation information, a value indicating transmission of new data is set in a second field, and the downlink allocation information is included in a physical control channel. A coding unit generating a radio control signal; And

And a transmitter / receiver for transmitting the radio control signal to the reference signal transmitter and receiving an aperiodic reference signal from the reference signal transmitter after the transmission.
The method of claim 11,

The transceiver unit transmits a set including one or more pieces of information necessary for transmitting the aperiodic reference signal and state information indicating the set to the reference signal transmitting apparatus using higher layer signaling. Signal receiving device.
Transmitting and receiving unit for transmitting and receiving a signal with a reference signal receiving device;

A reference signal generator for generating a reference signal;

The transceiver receives a radio control signal including downlink allocation information from the reference signal receiving apparatus, and a value instructing transmission of new data in the downlink allocation information is set in a second field, and retransmission version information is received. And a control unit controlling the transceiver and the reference signal generator to transmit the aperiodic reference signal to the reference signal receiving apparatus when the first field to be provided is indication information indicating the transmission of the aperiodic reference signal. Signal transmission device.
The method of claim 13,

And the transmitter / receiver receives a set including one or more pieces of information necessary for transmitting the aperiodic reference signal and state information indicating the set using higher layer signaling from the reference signal receiving apparatus.
The reference signal receiving apparatus sets indication information indicating setting information necessary for aperiodic reference signal transmission of the reference signal transmitting apparatus in a redundancy version (RV) field providing retransmission version information in downlink allocation information, and transmits new data. Setting a value indicating a to a New Data Indicator (NDI) field and generating a radio control signal including the downlink allocation information and a physical downlink control channel (PDCCH);

Transmitting the radio control signal to the reference signal transmission device; And

And receiving an aperiodic reference signal from the reference signal transmitting apparatus according to the setting information indicated by the indication information, wherein the indication information is one or two bits in size, one necessary for transmitting the aperiodic reference signal. A method for receiving an aperiodic reference signal, characterized in that the information indicates a set including the above information.
Receiving a radio control signal including downlink allocation information from a reference signal receiving apparatus and being a physical downlink control channel (PDCCH);

If the value of the New Data Indicator (NDI) field in the downlink allocation information is a value indicating transmission of new data, the RV (Redundancy Version) field indicating retransmission version information indicates configuration information necessary for aperiodic reference signal transmission. Extracting indication information to be performed; And

And transmitting the aperiodic reference signal to the reference signal receiving apparatus according to the setting information indicated by the extracted indication information, wherein the indication information has a size of 1 or 2 bits and is used to transmit the aperiodic reference signal. And information indicating an aggregation comprising one or more pieces of information required.