WO2012093911A2 - Method and device for transmitting and receiving aperiodic reference signal in communication system using multiple component carriers - Google Patents

Abstract

The present invention relates to a wireless communication system, and particularly, the invention transmits an aperiodic reference signal in a communication system using multiple component carriers, wherein: component carrier identification information, which is the target of an aperiodic reference signal transmission, is included in downlink control information that is transmitted through a physical control channel; and transmission parameter information for an aperiodic reference signal transmission of a corresponding CC is transmitted through separate signaling. According to the present invention, a terminal is capable of stably transmitting an aperiodic reference signal (for example, A-SRS) in a communication system using a plurality of component carriers (CCs), and particularly, an uplink grant and an A-SRS grant of the information of a DCI format 4 are configured relative to different CCs, thereby indicating more efficient A-SRS transmissions in a multi-cell environment.

Description

Method and apparatus for transmitting and receiving aperiodic reference signal in communication system using multi-element carrier

The present invention relates to a method and apparatus for aperiodic reference signal transmission and reception in a wireless communication system, in particular, a communication system using a multi-element carrier.

In particular, in transmitting an aperiodic reference signal in a communication system using a multi-component carrier, aperiodic to downlink control information (hereinafter referred to as "DCI") transmitted through a physical control channel. Component Carrier (hereinafter referred to as 'Component Carrier' or 'CC') identification information, which is a target of reference signal transmission, is included, and transmission parameter configuration information for aperiodic reference signal transmission of the CC includes separate signaling. Send it through.

As communication systems evolve, consumers, such as businesses and individuals, are demanding wireless terminals that support a variety of services.

Current mobile communication systems such as 3GPP, Long Term Evolution (LTE), and Long-Term Evolution-Advanced (LTE-A) (LTE-A) are used to provide video, wireless data, and the like. As a high-speed large-capacity communication system capable of transmitting and receiving various data, not only the development of technology capable of transmitting large-capacity data that is equivalent to a wired communication network is required, but also the system performance by minimizing the reduction of information loss and improving the system transmission efficiency. There is a need for an appropriate error detection method that can improve the performance.

In addition, in various current communication systems, various reference signals or reference signals have been proposed in order to provide information on a communication environment to the counterpart device through uplink or downlink.

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

On the other hand, these reference signals are generally generated by the transmission apparatus of the reference signal, that is, the UE in the case of the uplink reference signal, and periodically generated by the base station apparatus in the case of the downlink reference signal and transmitted to the reference signal receiving apparatus.

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 addition, unlike a communication system using one carrier consisting of one frequency band to date, a method of using a plurality of component carriers in a recently discussed wireless communication system has been discussed.

As described above, in case of a communication system using a plurality of CCs, each CC may function as one cell, and in a wireless communication system which is recently discussed, it is not necessary to transmit a channel estimation reference signal for each CC. However, the specific method is not determined.

In consideration of such a situation, there is a need for a specific transmission scheme of an aperiodic channel estimation reference signal in a communication system using a plurality of CCs.

An embodiment of the present invention provides a signaling method for aperiodic transmission of a reference signal in a communication system using a plurality of CCs.

An embodiment of the present invention provides an aperiodic SRS (hereinafter referred to as 'A-SRS') transmission and reception method in a communication system using a plurality of CCs.

An embodiment of the present invention provides a technique of using a predetermined field of downlink control information transmitted on a physical control channel to indicate a CC to transmit A-SRS in a communication system using a plurality of CCs.

According to an embodiment of the present invention, in a communication system using a plurality of CCs, identification information of a CC to transmit A-SRS is transmitted through a physical control channel, and A-SRS configuration parameter information is transmitted through separate signaling. to provide.

An embodiment of the present invention provides a technology capable of obtaining identification information of a CC for transmitting A-SRS through an A-SRS configuration parameter information indicator in a communication system using a plurality of CCs.

According to an embodiment of the present invention, a non-periodic reference signal reception method by an aperiodic reference signal receiver in a wireless communication system using a plurality of component carriers, and includes a physical control channel including information on the component carrier identification of the aperiodic reference signal Generating and transmitting downlink control information of the non-periodic reference signal, and generating and transmitting the non-periodic reference signal configuration parameter information of the component carrier identification information and the component-specific aperiodic reference signal for each component carrier signaled separately. It provides a non-periodic reference signal receiving method comprising the step of receiving.

Another embodiment of the present invention is an apparatus for receiving an Aperiodic Sounding Reference Signal (hereinafter referred to as 'A-SRS') in a wireless communication system using a plurality of CCs. A-SRS transmission target CC identification information generating unit for generating A-SRS transmission target CC identification information for indicating a CC to transmit the A-SRS of the link CC, and a downlink including the generated A-SRS transmission target CC identification information DCI processing unit for generating link control information (DCI), PDCCH transmission unit for transmitting the generated DCI to the physical control channel to the terminal, A-SRS transmission target CC that the terminal is determined by the A-SRS transmission target CC identification information It provides an aperiodic sounding reference signal receiver including an A-SRS receiver for receiving the A-SRS transmitted through.

Another embodiment of the present invention is a method for transmitting an A-SRS in a wireless communication system using a plurality of CCs, the method comprising the steps of: receiving a DCI including the A-SRS transmission target CC identification information on a physical control channel; Receiving A-SRS configuration parameter information to be used by the A-SRS transmission target CC through higher-level signaling separate from the physical control channel, and A-SRS to transmit A-SRS based on the A-SRS transmission target CC identification information. Determining the SRS transmission target CC, determining the A-SRS configuration parameter information to be used by the A-SRS transmission target CC, and generating the A-SRS using the determined A-SRS configuration parameter information. It provides a method for transmitting the aperiodic sounding reference signal comprising the step of transmitting through the A-SRS transmission target CC.

Another embodiment of the present invention is an apparatus for transmitting A-SRS in a wireless communication system using a plurality of CCs, the DCI receiving unit for receiving a DCI including the A-SRS transmission target CC identification information on a physical control channel, An RRC processing unit for receiving A-SRS configuration parameter information for each CC to be used by the A-SRS transmission target CC through RRC signaling, and an A-SRS transmission target CC for transmitting the A-SRS based on the A-SRS transmission target CC identification information. Using the A-SRS transmission target CC determination unit for determining the A-SRS configuration parameter information for determining the A-SRS configuration parameter information for use by the A-SRS transmission target CC, and the determined A-SRS configuration parameter information. By providing an A-SRS to provide an aperiodic sounding reference signal transmitter including an A-SRS transmitter for transmitting through the A-SRS transmission target CC.

Another embodiment of the present invention is a method for transmitting and receiving an A-SRS in a wireless communication system using a plurality of CCs, the A-SRS receiving apparatus A-SRS transmission target to downlink control information (DCI) of the physical control channel The component carrier identification information is included and transmitted to the SRS transmitting apparatus, and the SRS transmitting apparatus uses the A-SRS transmission parameter information for each component carrier signaled separately from the physical control channel and the A-SRS transmission target component carrier identification information. -SRS A-SRS is transmitted through a transmission target component carrier provides a method for transmitting and receiving a periodic sounding reference signal, characterized in that.

1 is a diagram schematically illustrating a wireless communication system to which an embodiment of the present invention is applied.

2 illustrates a general subframe and time slot structure of transmission data that can be applied to an embodiment of the present invention.

3 and 4 are tables showing configuration information of an SRS subframe that can be used in an embodiment of the present specification.

5 is a diagram illustrating configuration information on an SRS bandwidth.

6 and 7 illustrate examples of information that may be set in connection with SRS transmission in the present specification.

8 illustrates a component carrier structure of a multi-component carrier environment (CA environment) to which the embodiment is applied.

FIG. 9 illustrates an embodiment utilizing four states separated by two bits of DCI format 4 in a single element carrier environment.

10 is a flowchart illustrating an A-SRS receiving method according to an embodiment of the present invention.

FIG. 11 is an example of A-SRS transmission target CC identification information and an A-SRS configuration parameter set table matched when the terminal configures three CCs.

FIG. 12 illustrates an embodiment in which two CCs of a terminal are capable of A-SRS transmission simultaneously in both CCs.

FIG. 13 illustrates a data transmission state of each CC when an embodiment of the present invention is applied.

14 is a flowchart illustrating an A-SRS receiving method according to another embodiment.

15 is a functional block diagram of an A-SRS receiving apparatus according to an embodiment of the present invention.

16 is a flowchart illustrating an A-SRS transmission method according to an embodiment of the present invention.

17 is a functional block diagram of an A-SRS transmission apparatus according to an embodiment of the present invention.

Hereinafter, some embodiments of the present invention will be described in detail with reference to the accompanying drawings. In adding reference numerals to the components of each drawing, it should be noted that the same reference numerals are assigned to the same components as much as possible even though they are shown in different drawings. In addition, in describing the 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.

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

Wireless communication systems are used to provide various communication services such as voice, packet data, and the like.

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

Terminal 10 in the present specification is a generic concept that means a user terminal in wireless communication, WCDMA and the UE in GSM, LTE, HSPA, etc., as well as MS (MobileStation), UT (User Terminal), SS (Subscriber) in GSM It should be interpreted as a concept that includes both stations and wireless devices.

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

In the present specification, the terminal 10 and the base station 20 are two transmitting and receiving entities used to implement the technology or 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. .

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. In addition, a hybrid method combining the two methods may also be used.

One embodiment of the present invention can be applied to resource allocation in the field of asynchronous wireless communication evolving to LTE and LTE-A through GSM, WCDMA, HSPA, and synchronous wireless communication evolving to CDMA, CDMA-2000 and UMB. . The present invention should not be construed as being limited or limited to a specific wireless communication field, but should be construed as including all technical fields to which the spirit of the present invention can be applied.

Meanwhile, in an example of a wireless communication system to which an embodiment of the present invention is applied, one radio frame or radio frame includes 10 subframes, and one subframe includes two slots. can do.

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 region of the time axis and a plurality of subcarriers (or subcarriers) in the region of the frequency axis.

For example, a subframe consists of two time slots, and each time slot has seven symbols (Extended CP (cyclic extended) when using a normal cyclic prefix (CP) in the time domain. prefix)) and 180kHz bandwidth in the frequency domain (in general, one subcarrier has a bandwidth of 15kHz, so 180kHz bandwidth corresponds to a total of 12 subcarriers). It may include corresponding subcarriers. The time-frequency domain defined by one slot on the time axis and a bandwidth of 180 kHz on the frequency axis may be referred to as a resource block or a resource block (RB), but is not limited thereto.

2A illustrates a general subframe and time slot structure of transmission data that can be applied to an embodiment of the present invention.

Referring to FIG. 2A, the transmission time of a frame is divided into TTIs (transmission time intervals) of 1.0 ms duration. The terms TTI and subframe may be used in the same meaning, and the frame is 10 ms long and includes 10 TTIs.

2b illustrates a general structure of a time-slot according to an embodiment of the present invention.

Referring to FIG. 2B, a TTI is a basic transmission unit, where one TTI includes two time slots 202 of equal length, each time slot having a duration of 0.5 ms. The time-slot includes a plurality of long block LBs 203 corresponding to each symbol. LBs are separated by cyclic prefixes. In this case, the cyclic prefix includes a normal cyclic prefix and an extended cyclic prefix according to the length thereof. In the case of using the normal cyclic prefix, the plurality of LBs includes 7 in one time-slot and is extended. In the case of using a cyclic prefix, the plurality of LBs includes six or three in one time-slot.

Taken together, one TTI or subframe may contain 14 LB symbols when using normal cyclic prefixes, typically 12 LB symbols when using extended cyclic prefixes or 6 LB symbols in special cases. It may include, but the present specification is not limited to such a frame, subframe or time-slot structure.

2C illustrates the configuration of one resource block (RB) 230 during one subframe or TTI 201 according to an embodiment of the present invention, where each TTI or subframe is a case of normal cyclic prefix in the time domain. In the case of 14 symbols (axis) or extended cyclic prefix, 12 (or 6) symbols (axis) 203 are divided. Each symbol (axis) may carry one OFDM symbol.

In addition, the total system bandwidth of 20 MHz is divided or divided into subcarriers 205 having different frequencies. For example, as mentioned above, an area composed of one slot in the time domain and subcarriers corresponding to a bandwidth of 180 kHz in the frequency domain (typically 12 subcarriers when having a bandwidth of 15 kHz per subcarrier) is allocated. It may be called a block or resource block (RB).

For example, a bandwidth of 10 MHz within 1 TTI may include 50 RBs in the frequency domain.

Each grid space constituting the resource block RB may be referred to as a resource element (hereinafter, referred to as a RE).

For example, in a resource region corresponding to a bandwidth of 180 kHZ in an area of the time axis and in a region of the time axis, a normal cyclic prefix is used and the frequency bandwidth of one subcarrier is 15 kHz. There may be a total of 14 (symbols) × 12 (subcarriers) = 168 REs in each resource region.

Meanwhile, as one of the current wireless communication schemes, a demodulation reference signal (DMRS) and a sounding reference signal are defined as reference signals transmitted from a terminal to a base station in LTE and LTE-A communication systems.

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

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

In the following specification, a process and method of 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, which is an embodiment thereof. However, the present invention is not limited to an SRS or a reference signal for channel estimation or channel measurement. It should be understood as a concept that includes all kinds of reference signals used in the link.

3 and 4 are tables showing configuration information of an SRS subframe that can be used by one embodiment of the present specification.

The transmission subframe of the periodic sounding reference signal (Periodic SRS) is determined by srs-SubframeConfig, which is a parameter indicated by 310 of FIG. 3. The srs-SubframeConfig (4-bit) 310 is transmitted in a higher layer as a cell-specific parameter and SRS transmission is possible in the last symbol of a subframe satisfying Equation 1.

[Equation 1]

In Equation 1, 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.

3 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 offset of an actual transmission subframe are defined.

That is, when the srsSubframeConfiguration value is 8 (1000 in binary), for example, SRS is transmitted in the second and third subframes every 5 subframes (T _SFC is 5,

Is {2, 3}). In this case, 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.

By the SRS setting, the SRS may be transmitted periodically in each radio frame or transmission period for each cell (base station).

Meanwhile, the base station informs each terminal of the transmission period and offset of the SRS through the SRS configuration index (10-bit) 410 of FIG. 4, 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 I _SRS = 20, the transmission period is 20ms, and the offset is 3ms, which is the value of I _SRS minus 17.

5 is a diagram illustrating configuration information on an SRS bandwidth. SRS bandwidth configuration (SRS bandwidth configuration (3-bit), 510) and SRS bandwidth (SRS bandwidth (2-bit), 520). The SRS bandwidth setting (C _SRS ) is a cell specific parameter and the same value is transmitted to all terminals in the cell. On the other hand, SRS bandwidth B _SRS ) is a UE-specific parameter that can be assigned different values to each terminal. One of four SRS bandwidths determined by the C _SRSs is selected for the UEs in the cell, and the size of the SRS bandwidth that the UE transmits is determined through the UE-specific parameter B _SRS . C _SRS and B _SRS are parameters transmitted from higher layers and their values depend on the system bandwidth. 5 shows that the RB range indicating system bandwidth is 40 <RB.

In the example of 60, FIG. 5 shows that when C _SRS = 2 and B _SRS = 2, the UE

Has the value of. This is the SRS transmission bandwidth (

) Means 4RB and N ₂ is used as a value for the next SRS transmission. In other words, using the C _SRS value and the B _SRS value, the range of frequencies at which the SRS can be transmitted and the range of the corresponding frequencies (

Information N ₂ at which point can be started. That is, if C _SRS = 2 and B _SRS = 2, all four RBs (

= 4) means to transmit the SRS.

6 and 7 illustrate examples of information that may be set in connection with SRS transmission in the present specification. A comb means that the comb is configured to transmit by dividing the frequency bandwidth in transmitting the SRS. The comb parameter in FIG. 6 means information indicating that the SRS can be transmitted in the even or odd subcarriers in the SRS transmission. For example, Comb0 may refer to an even subcarrier and Comb1 may refer to an odd subcarrier. By using the Comb parameter, two terminals pointing to the same SRS resource on the frequency can be distinguished through a frequency position and an SRS bandwidth.

In FIG. 7, a total of eight cyclic shifts are shown. 3 bits of information may be transmitted to indicate a cyclic shift.

In order to transmit the SRS, it is necessary to set various information, that is, an area of a resource to which the SRS is to be transmitted, time information to transmit the SRS, and the like. In addition, in order to transmit an aperiodic SRS (hereinafter referred to as 'A-SRS' or 'aperiodic SRS'), information about these resources and time needs to be set. In addition, since aperiodic SRS may require fast SRS check at any particular time, it may be necessary to transmit and receive A-SRS faster through a physical channel than to transmit and receive information in RRC (Radio Resource Control).

Meanwhile, in the physical channel, transmission and reception of information related to uplink and information related to downlink may exist. In an embodiment of the present disclosure, we will look at including A-SRS-related information in one or two bits due to the limitation of information that can be loaded on a physical channel. Of course, the present invention can be applied to a larger range of information (3 bits or more) in addition to 1 to 2 bits in applying an embodiment of the present specification. However, each embodiment of the present invention will be described based on the minimum usable bit size.

An embodiment of a physical channel to include the 1 to 2 bits will be described based on DCI format 0 or DCI format 4.

DCI format 0 and DCI format 4 may be used as a transmission format of a physical control channel to include A-SRS transmission information.

For example, in DCI format 0, a new 1-bit for triggering A-SRS transmission may be added, thereby instructing transmission of A-SRS to be initiated, and A-SRS transmission parameter for specific A-SRS transmission. They may be transmitted in a separate higher stage signaling (eg, RRC) signal.

In addition, in DCI format 4, 2-bit may be added to indicate A-SRS transmission information, and one of these states (1-state) may not transmit A-SRS (No A-SRS Activation). It is used for indicating and can transmit information on the A-SRS transmission parameter using the remaining three states (3-state).

On the other hand, in one of the communication systems currently used, one carrier having a constant frequency bandwidth (up to 20 MHz) is used. In such a wireless communication system, the SRS and the A-SRS for one component carrier are determined by the UE in the above-described manner. Transmitting to base station.

However, in the new communication system being discussed recently, discussions are being made to expand the bandwidth to satisfy the required performance, and in order to increase the bandwidth, a unit carrier that an existing communication terminal can have is defined as an element carrier and these element carriers are defined. Up to five bundles are being discussed.

8 illustrates a component carrier structure of a multi-component carrier environment (CA environment) to which the embodiment is applied.

As shown in FIG. 8, in a CA environment, a plurality of conventional 20 MHz component carriers (eg, CC1 to CC4 represented by 110 to 140 of FIG. 8) may be bundled and used. For example, five component carriers may be bundled together. A technology that can be extended to have a bandwidth of up to 100 MHz, and a plurality of component carriers in such a manner is called a carrier aggregation technology (CA). The frequency bands that can be allocated as component carriers may be continuous or discontinuous.

With respect to carrier aggregation technology, a number of component carriers may be referred to as backwards compatible carriers (hereinafter referred to as "compatible carriers" or "BCs"), non-backwards compatibility carriers, and extension carriers. ) Can be divided into three types.

The compatible carrier is a carrier that can be applied to all existing versions of LTE, and may operate as a single (alone) carrier or as part of carrier aggregation. In time division duplex (TDD), the bandwidth and location of uplink and downlink should always be the same. In addition, in FDD (Frequency Division Duplex), uplink and downlink should always have cell-specific connection settings and may exist in pairs.

On the other hand, incompatible carriers (hereinafter referred to as "non-backwards compatibility carrier" or "non-compatible carriers" or "NBC") are not accessible to the UE by the communication system so far, and operate as a single (alone) if generated from a duplex distance. It is possible to do this, otherwise it is a carrier that operates only as part of a carrier aggregation.

In addition, an extension carrier (hereinafter referred to as an "extension carrier" or "ExC") may be operated as a part of at least one component carrier set including a carrier that cannot be operated singly (single) and can be used alone. Only used, it is a carrier used for bandwidth expansion.

In such a multi-carrier environment, one CC in which a UE initially establishes a connection (connection or RRC connection) among various CCs is called a primary CC (hereinafter referred to as a 'PCC' or 'main CC'). It is called.

Preferably, the PCC is responsible for a connection or RRC connection management function that manages a plurality of CCs provided by the UE and the BS and is responsible for signaling, and is connection information associated with the UE. Although it is used as a special element carrier that manages UE context and manages security key values for security setting between the terminal and the base station, it is not limited to these terms or functions.

In addition, such a major carrier (PCC) is connected to the terminal is always in the activation (Activation) state in the RRC connection mode (RRC Connection Mode).

In the above description, CCs allocated to UEs in addition to PCCs, which are initially connected with UEs (Connection or RRC Connection), among CCs, are also referred to as secondary CCs (hereinafter referred to as secondary CCs). SCC). Preferably, the subcarrier carrier (SCC) is an extended carrier for the additional resource allocation in addition to the main carrier (PCC) and can be divided into an activation or deactivation state.

In the present specification, the SCC is used as a comprehensive concept including all component carriers except the PCC among the multi-component carriers, and after the terminal configures some of the SCCs, the terminal is activated and then transmits and receives data therethrough. .

The activation state refers to a state in which downlink control information and downlink data information can be received. In addition, channel quality information (CQI) can be measured. On the other hand, the inactive state refers to a state in which downlink control information and downlink data information cannot be received. In addition, channel quality information (CQI) cannot be measured.

In addition, each SCC is downlink (hereinafter referred to as "DL" or "downlink" or "downlink") or uplink (hereinafter referred to as "UL" or "uplink" or "uplink"). It may be assigned and used separately for each.

In a multi-element carrier environment, when the terminal is connected to the base station, the PCC is connected to the RRC like a conventional single-element carrier and thus instructs periodic transmission of the SRS in the manner described above, and the terminal periodically sends the SRS accordingly. Can be transmitted to the base station.

However, in such a multi-component carrier (CA) environment, there is no situation in which aperiodic SRS transmission is not defined for various CCs such as PCC and other SCCs.

Meanwhile, in a communication system using one CC, the A-SRS transmission mechanism may be implemented as follows according to DCI format 0 definition or DCI format 4 usage.

1) Method using DCI format 0

In DCI format0, new 1-bit information may be added for triggering A-SRS transmission, and thus, instructing the UE to start A-SRS transmission on a corresponding CC. On the other hand, parameters for A-SRS transmission (SRS configuration parameters) are delivered to the terminal by higher-end signaling such as RRC. That is, parameters such as SrsBandwidth, FrequencyDomainposition, transmissionComb, and cyclic shift for A-SRS transmission are composed of one set, which is transmitted to the terminal through RRC signaling.

When the A-SRS transmission triggering bit of DCI format 0 becomes 1 (may be 0 according to definition), the UE allocates the last symbol A-SRS of the corresponding subframe, but includes frequency bandwidth, start position, comb, and cyclic The shift and the like may be determined according to a separate RRC transmitted A-SRS configuration parameter set. The time-frequency resource region to which the A-SRS is allocated is modulated into an OFDM signal and transmitted to the base station. The received base station estimates the channel state information of the corresponding channel using the A-SRS and can be used for later scheduling. .

2) Method using DCI format 4

Unlike DCI format 0, DCI format 4 can be defined to use two bits of information for A-SRS triggering or configuration, thus using a total of four states to determine the transmission state of the A-SRS. I can express it.

One of the four states (for example, the state represented by '00') is used to indicate "No A-SRS activation" that it does not transmit A-SRS. SRS transmission may be indicated.

That is, DCI format 4 may be added with two new bits related to A-SRS transmission, one of which is used to indicate that no A-SRS is transmitted, and 3 using three other states. Discussing different kinds of A-SRS configuration parameter sets is discussed, and FIG. 9 shows an example of such a scheme.

FIG. 9 illustrates an embodiment utilizing four states separated by two bits of DCI format 4 in a single element carrier environment.

As shown in FIG. 9, state 4 represents No A-SRS Activation among the four states indicated by the 2 bits related to A-SRS transmission of DCI format 4, and the remaining states 1 to 3 are respectively. It is defined to correspond to the first A-SRS configuration parameter set 910 to the third A-SRS configuration parameter set 930 which are three types of A-SRS configuration parameter sets.

For reference, in FIG. 9, matching of 2 bits related to A-SRS transmission of DCI format 4 and its state is merely exemplary.

The UE receives and stores the A-SRS configuration parameter set information or the A-SRS configuration parameter set table as semi-static in RRC as shown in FIG. 9, and the A-SRS of DCI format 4 transmitted by the base station. After checking two bits related to transmission, one of the four A-SRS configuration parameter sets among the four states is selected to transmit the A-SRS.

For example, if 2 bits related to A-SRS transmission of DCI format 4 transmitted by the base station is '01', the UE recognizes that it is in state 1, and thus is defined in the second A-SRS configuration parameter set 920 corresponding thereto. The A-SRS is transmitted based on the various parameters.

Using this scheme, the base station can dynamically use one of three types of A-SRS configuration parameter sets for a specific terminal, thereby obtaining A-SRS transmission gains.

However, this scheme using DCI format 4 reduces the number of branches for A-SRS allocation in a communication system using a single component carrier as described above. There may be some doubt as to how much it would benefit to use only one set of A-SRS configuration parameters and three sets in DCI format 4.

In addition, the above embodiments are all limited to the case of using a single CC, and when using a plurality of CCs in a CA environment, the definition of A-SRS transmission should be considered.

The present invention is proposed by such a request, and is a method for transmitting and receiving A-SRS in a communication system using a plurality of CCs, and the downlink control information of a physical control channel (for example, a base station) in an SRS receiver (for example, a base station). A-SRS transmission target component carrier identification information is included in DCI) and transmitted to an SRS transmitting apparatus (for example, a terminal, etc.), and the SRS transmitting apparatus separately transmits A-SRS transmission parameter information for each component carrier and the A-SRS signaled separately. The A-SRS is transmitted through the A-SRS transmission target component carrier using the SRS transmission component CC identification information.

The A-SRS transmission element CC identification information may be represented by one or more of four states represented by 2 bits, and the downlink control information may be DCI format 4, but is not limited thereto.

The 'A-SRS transmission element CC identification information' is not limited to its English language or expression, and means information of two or more bits additionally defined in DCI format 4 to indicate A-SRS transmission. It should be understood as comprehensive and may be interpreted as being distinct from a Carrier Indicator Field (CIF) which is already defined to distinguish component carriers in the PDCCH.

The A-SRS transmission parameter information may be included in an A-SRS transmission parameter set table including an A-SRS configuration parameter set allocated to each CC, but is not limited thereto.

In addition, the A-SRS transmission parameter information, the A-SRS configuration parameter set or the A-SRS transmission parameter set table may be transmitted to the SRS transmitter through higher-end signaling, and the higher-end signaling may be RRC. It is not limited to this.

A-SRS configuration parameter set for each component carrier includes SrsBandwidth (bandwidth information), FrequencyDomainposition (band position information), transmissionComb (transmission comb information), cyclic shift (cyclic shift information), and number of antenna ports (antenna port number information). , A-SRS transmission element carrier identification information may be included, and may include, but not limited to, SrsHoppoingBandwidth (hopping bandwidth information), duration (duration information), etc. according to whether or not SRS hopping is performed.

In addition, the component carrier for transmitting the DCI is a primary component carrier (PCC) or a secondary component carrier (SCC), and the A-SRS transmission target component carrier indicated by the A-SRS transmission target component carrier identification information is the primary CCI is transmitted It may be a separate uplink component carrier (UL CC) rather than the component carrier or the secondary component carrier.

That is, in one embodiment of the present invention, unlike DCI format 0, DCI format 4 may be defined to use 2-bit information for A-SRS triggering or configuration, and thus, A-SRS using a total of four states. It is possible to express the transmission state of, and one of four states (for example, the state represented by '11') is used to indicate "No A-SRS activation" that does not transmit A-SRS. In addition, the remaining three states can be used to designate the A-SRS transmission target CC to transmit the A-SRS. Of course, the A-SRS configuration parameter information to be used by each A-SRS transmission target CC may be transmitted to the UE through separate signaling (for example, higher layer signaling such as RRC signaling of layer 3).

Hereinafter, an embodiment of a reference signal to which the present invention can be applied will be described with reference to SRS, but is not limited thereto. As well as other uplink reference signals such as DM-RS, all the technical concepts of the present invention may be applied. It should be understood as a concept including a reference signal.

10 is a flowchart illustrating an A-SRS receiving method according to an embodiment of the present invention.

The A-SRS reception method according to the present embodiment is generally performed by an SRS receiver such as an eNB, but is not limited thereto. In the case of a downlink reference signal, the A-SRS reception method may be performed by a UE. .

First, the SRS receiving apparatus generates downlink control information of a physical control channel including A-SRS transmission target component carrier identification information and transmits the generated downlink control information to the SRS transmitting apparatus (S1010), and the SRS transmitting apparatus generates the A-SRS. And receiving the A-SRS transmitted through the A-SRS transmission target component carrier using the transmission target component carrier identification information and the separately signaled A-SRS configuration parameter information for each component carrier (S1020). have.

Further, optionally, the method may further include transmitting the A-SRS configuration parameter information (set table) for each CC to the A-SRS transmitting apparatus through RRC, which is a separate signaling (S1005).

The physical control channel is a physical downlink control channel (PDCCH), the downlink control information may be DCI format 4, and the A-SRS transmission element CC identification information may be represented by 2 bits. Hereinafter, the configuration will be described as an example, but is not limited thereto. Other channels, information, bits, and the like may be used.

The field defined in DCI format 4 used in this embodiment consists of a total of A bits (a ₀ to a _A-1 ) including zero padding bits, of which two bits are A-SRS transmissions according to the present embodiment. Can be used as the target CC identification information.

Meanwhile, DCI format 4 used in the present embodiment is used for scheduling of a PUSCH in one uplink cell having a multi-antenna port transmission mode, and includes a carrier identification field of 0 or 3 bits, a resource block allocation and a hopping resource. Allocation bits, TPC indication bits of scheduled PUSCH, cyclic shift and OCC index fields (3 bits) for DM-RS, 2 bits of UL index, 2 bits of downlink allocation index (DAI), CQI request 1 or 2 bits, 1 bit of a multi-cluster flag, and the like, but are not limited thereto.

Of course, DCI format 4 used in the present embodiment may further include a 2-bit field as 'A-SRS transmission target CC identification information' as described above, and 'A-SRS transmission target CC identification information' It is not limited to the terms or expressions, and may be expressed differently in other expressions such as an SRS Request or an A-SRS Request.

In addition, the A-SRS transmission target CC identification information used in this embodiment is all forms defined in the DCI to identify the CC to transmit the A-SRS or to indicate the A-SRS configuration of the CC in accordance with the spirit of the present invention The state indicating R-configured A-SRS Parameter Set, which is currently under discussion, should be interpreted as including the information or field of the A-SRS transmission target CC according to this embodiment. It can also be used as information.

FIG. 11 is an example of A-SRS transmission target CC identification information and an A-SRS configuration parameter set table matched when the terminal configures three CCs.

FIG. 11 illustrates a case in which a terminal to perform A-SRS transmission includes three CCs CC1 and CC3 among five CCs CC0 to CC4, among which CC1 functions as a PCC which is a primary component carrier.

Referring to FIG. 10 and FIG. 11, the base station 2 bit information for specifying a CC to be A-SRS transmission target among the fields of DCI format 4 included in the PDCCH of the CC1 CC1 that is connected to the RRC Create and send to the terminal.

In addition, the terminal receives and stores the CC-specific A-SRS configuration parameter set table shown in FIG. 11 through higher-level signaling such as separate RRC signaling.

Upon receiving the information of the DCI format 4 including the 2-bit A-SRS transmission target CC identification information, the UE checks which CC among the currently configured CCs to transmit the A-SRS from the identification information, and transmits separately. The A-SRS configuration parameter set of the corresponding A-SRS transmission target CC is determined from the CC-specific A-SRS configuration parameter set table shown in FIG.

Subsequently, the terminal may include various parameters included in the corresponding A-SRS configuration parameter set (SrsBandwidth (bandwidth information), FrequencyDomainposition (band position information), transmissionComb (transmission comb information), cyclic shift (cyclic shift information), and number of According to antenna ports (antenna port number information) SrsHoppoingBandwidth (hopping bandwidth information), duration (duration information, etc.), A-SRS is allocated to a corresponding time-frequency resource space and transmitted to a base station.

For example, when the base station transmits the A-SRS transmission target CC identification information of '01' to the terminal in the DCI format 4 included in the PDCCH of the PC1 CCC in FIG. 11, the terminal is signaled in advance in FIG. 11. By referring to the CC-specific A-SRS configuration parameter set table as follows, it is confirmed that '01', which is the corresponding CC identification information of the A-SRS transmission target, is CC2, and according to various parameters of the A-SRS configuration parameter set corresponding to CC2, The SRS is generated and transmitted to the base station.

In this case, among the parameters included in the A-SRS configuration parameter set, SrsBandwidth (bandwidth information) and FrequencyDomainposition (band position information) are information indicating a frequency bandwidth to transmit the A-SRS and a start position in frequency space. It may be defined in a manner similar to that defined in 5, but is not limited thereto.

In addition, transmissionComb (transmission comb information) may be information that selectively indicates to transmit the SRS in the even or odd subcarriers in the A-SRS transmission, for example, Comb0 is the even subcarrier, Comb1 is It may refer to an odd subcarrier. By using the transmissionComb parameter, two terminals indicating the same SRS resource on the frequency can be distinguished through the frequency location and the A-SRS bandwidth.

Cyclic shift information may represent three bits of information for representing a total of eight states separated by 45 degree intervals in a complex space.

FIG. 12 illustrates an embodiment in which two CCs of a terminal are capable of A-SRS transmission simultaneously in both CCs.

In FIG. 12, a terminal is configured with two CCs CC1 and CC2 among five CCs CC0 to CC4, and among them, CC1 functions as a PCC which is a primary component carrier.

In the embodiment of FIG. 12, unlike in the case of FIG. 11, one of three states (one state is used for No A-SRS Activation identification) that can be identified by two bits of A-SRS transmission object identification information is CC1 and CC2. It can be used to instruct to transmit A-SRS in all.

That is, in the case of state 3 represented by '10' among three states, A-SRS transmission target CC identification information may be configured to transmit A-SRS in both CC1 and CC2. In this case, A-SRS configuration of FIG. The parameter set table also matches the A-SRS configuration parameter set 1230 used when transmitting A-SRS in both CC1 and CC2.

Other detailed operations and definitions of A-SRS configuration parameters are the same as those of FIG. 11, and thus detailed descriptions thereof will be omitted to avoid duplication.

FIG. 13 illustrates a data transmission state of each CC when an embodiment of the present invention is applied.

In particular, FIG. 13 illustrates a case where cross-carrier scheduling for instructing A-SRS transmission is applied in FDD, and only control information indicating data transmission in UL CC1 using PDCCH of downlink DL CC1 which is a PCC. Rather, A-SRS transmission may be indicated through UL CC2. In this way, a method in which uplink data transmission and A-SRS transmission are independently indicated by different CCs may be similarly applied to TDD.

That is, in the nth subframe of FIG. 13, DCI format 4 information including 'A-SRS transmission target CC identification information 2 bits' indicating A-SRS transmission of UL CC2 is allocated in the PDCCH of DL CC1 (PCC). To transmit to the terminal. The PDCCH includes control information for transmitting predetermined data through UL CC1 in the n + 4th subframe.

In this case, among control information in the PDCCH, control information for transmitting predetermined data through the UL CC1 in the n + 4th subframe may be allocated to the CIF, and the CIF may be 3-bit information to represent 5 or more CCs. Can be.

Of course, the two bits of the 'A-SRS transmission target CC identification information' defined in the embodiment of the present invention may be understood as a concept distinct from the above-described CIF.

That is, 'A-SRS transmission target CC identification information' may be interpreted to mean two or more bits of information additionally defined in DCI format 4 to indicate A-SRS transmission in addition to the existing CIF, but is not limited thereto. no.

Upon receiving such PDCCH through DL CC1, which is a PCC, the UE confirms that the A-SRS should be transmitted in an n + 5th subframe through UL CC2, which is an SCC, by checking UL CC identification information of the A-SRS.

In addition, the terminal generates an A-SRS according to the A-SRS configuration parameter set of the corresponding CC2 with reference to the A-SRS configuration parameter set table as shown in FIG. 11 or 12 received through separate RRC signaling and transmits it to the base station. Done.

In addition, since such PDCCH includes control information for transmitting predetermined data through UL CC1 which is a PCC in the n + 4th subframe, as shown in FIG. 13, the UL CC1 is the n + 4th subframe. Transmits predetermined data through PUSCH.

Meanwhile, n ', which is a subframe in which the UL CC2 transmits the A-SRS, may be determined as the next subframe after the subframe in which the UL CC1 transmits the PUSCH, but is not limited thereto.

In addition, according to the current standard content, since the A-SRS should be allocated to the last symbol of the corresponding subframe, it is expressed as shown in FIG. 13 but is not limited thereto.

Referring back to FIG. 13, FIG. 13 illustrates an example in which uplink allocation and A-SRS transmission occur in different UL CCs through DCI format 4, and independently uplink allocation and A-SRS allocation are performed. Can be directed.

That is, when uplink allocation is required for UL CC1 and A-SRS transmission is required for UL CC2, the base station is linked with UL CC1 and System Information Block 2 (SIB2) to instruct the UE to allocate uplink for UL CC1. DCI format 4 indicating uplink allocation is transmitted through a DL CC, and the DCI format 4 transmitted at this time includes information for A-SRS transmission in UL CC2 (that is, 2-bit A- for indicating UL CC2). SRS transmission target CC identification information) is carried.

Then, as shown in FIG. 13, when the A-SRS transmission time point is n, the PDCCH transmission subframe indicating A-SRS triggering is n '> = n among the A-SRS subframes of the corresponding CC (ie, UL CC2). A-SRS is transmitted in the first subframe that satisfies +4.

14 is a flowchart illustrating an A-SRS receiving method according to another embodiment.

In the embodiment of FIG. 14, the A-SRS receiving apparatus (for example, the base station) checks the state of the terminal and selectively transmits A-SRS configuration parameter information and DCI format according to whether a single CC or a plurality of CCs are configured. Include configurations that adopt configurations.

First, the base station eNB checks the state of the terminal (S1410). Checking the state of the terminal may specifically refer to checking the number of CCs configured or activated in the corresponding terminal, but is not limited thereto. May be checked at the same time.

The information checked by the base station in step S1410 may include an activated UL CC of the terminal, a data buffer state of the terminal, a channel estimation state for each CC of the terminal, but is not limited thereto.

Next, it is determined whether the number of CCs configured or activated in the corresponding UE is a single CC or a multiple CC (S1420).

When it is confirmed that a single CC is configured or activated, the base station generates an A-SRS configuration parameter set for the single CC and transmits it to the UE through RRC (S1430), and 1 or A-SRS transmission indicating a single CC is indicated. DCI format information (or a PDCCH including the same) is generated to include 2 bits of information and transmitted to the terminal as a PDCCH of the physical layer (S1440).

In this case, the DCI format including information indicating A-SRS transmission of a single CC may be DCI format 0 including 1 bit of identification information or DCI format 4 having 2 bits of identification information.

In addition, when DCI format 4 is used, as described with reference to FIG. 9, two or more (up to three) A-SRS configuration parameter sets of a single CC are generated and transmitted to the terminal in table form, which is represented by 2 bits. Three of the four states may be used to selectively specify one of a plurality of A-SRS configuration parameter sets.

On the other hand, in step S1420, when it is determined that there are a plurality of UL CCs configured or activated in the terminal, the base station as shown in Figure 11 or 12, A-SRS configuration parameter information for each of a plurality of CCs to transmit the A-SRS (I.e., generate a CC-specific A-SRS configuration parameter set table, etc.) and transmit the RRC to the UE (S1450).

In addition, the base station determines the CC (s) to transmit the A-SRS from among a plurality of CCs, as described in the embodiment below in Figure 10, and then generates the A-SRS transmission target CC identification information that can identify it with 2 bits After including the information in the DCI format 4, the DCI format 4 information is transmitted to the terminal (S1460).

Of course, in FIG. 14, the DCI information transmission steps S1440 and S1460 are performed after the A-SRS configuration parameter information transmission steps S1430 and S1450 of the CC in the case of both a single CC and a plurality of CCs. However, the present invention is not limited thereto, and the order may be changed or performed simultaneously.

Next, the base station receives the A-SRS signal transmitted through the corresponding CC (s) (S1470).

Referring to step S1470 in more detail, in the case of a single CC, the terminal confirms the instruction to perform A-SRS transmission on the CC (ie, PCC) according to the A-SRS indication information (1 bit or 2 bits), After confirming the A-SRS configuration parameter set of the CC transmitted through the RRC, the A-SRS is generated and transmitted accordingly, and the base station receives the transmitted A-SRS.

In addition, in the case of multiple CCs, the terminal recognizes the 2-bit A-SRS transmission target CC identification information included in the DCI format 4 information, and the CC selected by using a separate RRC-specific CC-specific A-SRS configuration parameter set table Check the A-SRS configuration parameters. If the A-SRS is generated through the corresponding A-SRS configuration parameter and then transmitted to the base station through the corresponding CC, the base station receives the A-SRS.

Of course, even in this case, as described in FIG. 10, the A-SRS configuration parameter set for each component carrier may include SrsBandwidth (bandwidth information), FrequencyDomainposition (band position information), transmissionComb (transmission comb information), and cyclic. The information includes shift (cyclic shift information), number of antenna ports (antenna port number information), and may include SrsHoppoingBandwidth (hopping bandwidth information), duration (duration information), etc. according to whether or not SRS hopping is performed.

In addition, in FIG. 14, when a plurality of CCs are configured or activated, the component carrier for transmitting DCI is a primary component carrier (PCC) or a secondary component carrier (SCC), and the A-SRS transmission target component carrier identification information indicated by The A-SRS transmission target component carrier may be a separate uplink component carrier (UL CC) other than the primary component carrier or the secondary component carrier on which the DCI is transmitted.

15 is a functional block diagram of an A-SRS receiving apparatus according to an embodiment of the present invention.

A-SRS receiving apparatus 1500 according to an embodiment A-SRS transmission target CC identification information for generating A-SRS transmission target CC identification information for indicating a CC to transmit the A-SRS among a plurality of CC configured in the terminal The DCI processing unit 1520 for generating a DCI including the generation unit 1510, the generated A-SRS transmission target CC identification information (for example, 2 bits), and transmitting the generated DCI to the UE through a physical control channel. The PDCCH transmitter 1530 includes an A-SRS receiver 1540 for receiving an A-SRS transmitted through the A-SRS target CC determined by the terminal as the A-SRS target CC identification information.

In addition, the A-SRS receiving apparatus 1500 according to an embodiment generates separate signaling (for example, by generating CC-specific A-SRS configuration parameter information for use when a plurality of CCs configured in the terminal transmit the A-SRS). CC-specific A-SRS configuration parameter information processing unit 1550 to be transmitted to the terminal via RRC signaling, etc. may optionally be included.

The A-SRS transmission target CC identification information generation unit 1510 is a 2-bit A-SRS transmission target CC as mentioned in FIG. 11 or FIG. 12 to indicate a CC for transmitting the A-SRS among a plurality of CCs configured in the terminal. It performs the function of generating identification information. That is, the A-SRS transmission target CC identification information may be set to indicate A-SRS transmission for up to three CCs, and in some cases, two CCs may be instructed to transmit A-SRS simultaneously.

Of course, this is the case where the A-SRS transmission target CC identification information is 2 bits, but in some cases, the A-SRS transmission target CC identification information may be 2 bits or more, in which case more A-SRS transmission CC or combination thereof It may be displayed.

In addition, although not shown, the DCI processing unit 1520 multiplexes the information of the total A bits (a ₀ to a _A-1 ) including the 2-bit A-SRS transmission target CC identification information according to an embodiment of the present invention. A CRC is added to the information element multiplexer and the information of the total A bits (a ₀ to a _A-1 ) to add c ₀ , c ₁ ,... c CRC Attacher for generating information bits of _K-1 , c ₀ , c ₁ ,... c After receiving and encoding the information bits of _K-1 , d ₀ ⁽ⁱ⁾ , d ₁ ⁽ⁱ⁾ ,. d _D-1 ⁽ⁱ⁾ Rate coding is performed on the channel coder for generating the encoding information and the coded blocks are e ₀ ⁽ⁱ⁾ , e ₁ ⁽ⁱ⁾ ,... e _E-1 ⁽ⁱ⁾ may include a rate matcher for generating information.

The PDCCH transmitter 1530 allocates DCI information generated according to the present embodiment to the corresponding resource space of a specific subframe, performs OFDM modulation, and then transmits the DCI information to the terminal through the PDCCH.

The A-SRS receiving unit 1540 generates and transmits the A-SRS using the A-SRS transmission target CC determined by the A-SRS transmission target CC identification information and the A-SRS configuration parameters matched with the CC. Perform the function of receiving it.

Optionally, the CC-specific A-SRS configuration parameter information processor 1550 generates CC-specific A-SRS configuration parameter information for use when the UE transmits A-SRS to each of the A-SRS transmission target CCs, thereby generating RRC signaling and the like. Performs a function of transmitting to the terminal.

Of course, in the A-SRS receiving apparatus of FIG. 15, the DCI may be defined by the definition of DCI format 4, and the CC transmitting the DCI or the PDCCH and the CC for transmitting the A-SRS may not be the same. (For example, the CC transmitting the A-SRS configuration parameter information for each PDCCH and CC is a PCC, and accordingly, the UL CC transmitting the A-SRS may be an SCC, and the A-SRS configuration parameter for each PDCCH and CC may be used. CC transmitting information is PCC or SCC, and accordingly, UL CC transmitting A-SRS may be separate CC except PCC and SCC)

16 is a flowchart illustrating an A-SRS transmission method according to an embodiment of the present invention.

In principle, the A-SRS transmission method according to an embodiment is performed by the terminal. However, when the reference signal to which the present embodiment is applied is a downlink reference signal, it may be performed by the base station.

The A-SRS transmission method according to the present embodiment comprises the steps of receiving A-SRS configuration parameter information to be used by the A-SRS transmission target CC through separate higher-end signaling (S1610), and A-SRS transmission target CC identification information. Receiving a DCI including (S1620), Determining the A-SRS transmission target CC to transmit the A-SRS based on the A-SRS transmission target CC identification information (S1630), and the separate higher-end signaling Determining an A-SRS configuration parameter set of the target CC based on the A-SRS configuration parameter information to be used by the A-SRS transmission target CC received through S1640 and using the determined A-SRS configuration parameter information After generating the A-SRS and transmitting through the A-SRS transmission target CC (S1650) may be configured.

Hereinafter, each step will be described in more detail.

First, the UE receives the A-SRS configuration parameter information to be used by the A-SRS transmission target CC through RRC signaling. (S1610) In principle, the RRC signaling is performed through the CC transmitting the DCI, but is not limited thereto.

In addition, the terminal receives a DCI transmitted by the base station through the PDCCH (S1620). Of course, the receiving DCI may be data of DCI format 4 including 2 bits of A-SRS transmission target CC identification information, but is not limited thereto.

The A-SRS configuration parameter information includes SrsBandwidth (bandwidth information), FrequencyDomainposition (band location information), transmissionComb (transmission comb information), cyclic shift (cyclic shift information), number of antenna ports SrsHoppoingBandwidth (hopping bandwidth) Information), duration (duration information), etc., but is not limited thereto.

In addition, the A-SRS configuration parameter information received by the RRC in step S1610 may be a plurality of A-SRS configuration parameter set table that can be used by a single CC as shown in FIG. 9, or as shown in FIG. 11 or 12. It may also be a CC-specific A-SRS configuration parameter set table matched for each use separately.

Meanwhile, the terminal receiving the DCI and the A-SRS configuration parameter information determines the UL CC to which the A-SRS should be transmitted through the A-SRS transmission target CC identification information (2 bits) included in the DCI (S1630).

In particular, when determining the A-SRS transmission target CC, each of up to three CCs may be determined as the A-SRS transmission target CC as shown in FIG. 11, but as shown in FIG. You might decide. This may be implemented differently according to the number of bits of the A-SRS transmission target CC identification information and the number of UL CCs used by the terminal.

The A-SRS transmission target CC determined at this time may be the same CC as the CC which performed DCI transmission or RRC signaling, or may be different CCs.

In step S1640, the A-SRS configuration parameter set to be used by the corresponding A-SRS transmission target CC is determined using the A-SRS configuration parameter information for each CC received through the RRC as shown in FIG. 11 or 12.

In addition, S1650 is a process of generating an A-SRS using the determined A-SRS configuration parameter set information and transmitting the A-SRS to the eNB through the A-SRS transmission target CC.

Through the A-SRS transmitted in this way, the base station estimates the channel state of the corresponding A-SRS transmission CC and can be used for future scheduling. Particularly, all of the CCs (especially SCCs) configured by the user equipment without a separate process of uplink allocation It is possible to accurately estimate the channel state.

17 is a functional block diagram of an A-SRS transmission apparatus according to an embodiment of the present invention.

The A-SRS transmitting apparatus 1700 according to an embodiment includes a DCI receiver 1710 that receives a DCI including the A-SRS transmission target CC identification information, and an A-SRS transmission target CC to be used by the A-SRS transmission target CC through RRC signaling. An RRC processing unit 1720 that receives SRS configuration parameter information, and an A-SRS transmission target CC determination unit 1730 that determines an A-SRS transmission target CC to which the A-SRS is transmitted based on the A-SRS transmission target CC identification information. ), An A-SRS configuration parameter determiner 1740 for determining A-SRS configuration parameter information to be used by the A-SRS transmission target CC, and an A-SRS generated using the determined A-SRS configuration parameter information. Thereafter, the A-SRS transmission unit may be configured to include an A-SRS transmission unit 1750 to transmit through the CC.

The A-SRS transmitter 1700 is preferably implemented in the terminal (UE) or separately implemented in conjunction with the terminal, but is not limited thereto.

The DCI receiver 1710 performs a function of receiving a DCI transmitted from a base station through a PDCCH, and the DCI received may be DCI format 4 data including 2 bits of A-SRS transmission target CC identification information, but is not limited thereto. It doesn't happen.

The RRC processing unit 1720 receives A-SRS configuration parameter information to be used by the A-SRS transmission target CC as RRC signaling, and the received A-SRS configuration parameter information may be used by a single CC as shown in FIG. 9. 11 may be an A-SRS configuration parameter set table, or as shown in FIG. 11 or FIG. 12, a plurality of CC-matched A-SRS configuration parameter set tables may be used individually.

On the other hand, the RRC signaling is carried out through the CC, that is, the PCC transmitting the DCI, but is not limited thereto. Each A-SRS configuration parameter set information includes SrsBandwidth (bandwidth information), FrequencyDomainposition (band position information), and transmissionComb (transmission). Comb information), cyclic shift (cyclic shift information), number of antenna ports (antenna port number information), SrsHoppoingBandwidth (hopping bandwidth information), duration (duration information), and the like.

Of course, the DCI receiving unit 1710 and the RRC processing unit 1720 may be integrated into one component.

The A-SRS transmission target CC determination unit 1730 performs a function of determining the UL CC that should transmit the A-SRS through the A-SRS transmission target CC identification information (2 bits) included in the received DCI, The A-SRS transmission target CC determined when may be one of up to three CCs as shown in FIG. 11, but two or more CCs may be determined as A-SRS transmission target CCs simultaneously as shown in FIG. 12.

In addition, the determined A-SRS transmission target CC may be the same CC as the CC performing the DCI transmission or RRC signaling, A-SRS cross-carrier scheduling can be enabled as in the present invention and the DCI and RRC signaling CC Is PCC, and the determined A-SRS transmission target CC may be another SCC other than the PCC. In addition, the DCI and RRC signaling CC may be a PCC or SCC, and the determined A-SRS transmission target CC may be another CC other than the PCC and the SCC.

The A-SRS configuration parameter determiner 1740 uses the A-SRS configuration parameter set table for each CC received through the RRC as shown in FIG. 11 or FIG. 12 to determine the A-SRS to be used by the corresponding CC. Determine a set of configuration parameters.

The A-SRS transmitter 1750 generates an A-SRS using the determined A-SRS configuration parameter set information and transmits the A-SRS to the eNB via the A-SRS transmission target CC.

According to the above embodiments, in a communication system using a plurality of CCs, a CC for transmitting an aperiodic reference signal is indicated using downlink control information of a physical control channel, and a parameter required for aperiodic reference signal transmission. By separately signaling, a UE can stably transmit an aperiodic reference signal (for example, A-SRS) in a communication system using a plurality of CCs.

In particular, since uplink allocation (UL Grant) and A-SRS allocation of information of DCI format 4 may be configured for different CCs in a CA environment, more efficient A-SRS transmission may be indicated in a multi-cell environment. That is, since the DCI including the A-SRS transmission target CC identification information and the CC (for example, PCC) for transmitting the A-SRS configuration parameter information and the CC (for example, SCC) for actually transmitting the A-SRS may differ from each other. In the cell environment, there is an advantage in that channel estimation for UL CC is possible without uplink allocation for all UL CCs.

In addition, since the channel estimation for the UL CC is possible without uplink allocation for all UL CCs in a multi-cell environment, it is possible to provide a resource allocation opportunity, thereby providing a scheduling gain.

In addition, when there is no uplink data transmission (PUSCH) in the CC to transmit the A-SRS, since the A-SRS transmission can be indicated without a separate uplink allocation (UL grant), an unnecessary uplink for indicating the A-SRS transmission Link allocation can be prevented to reduce PDCCH signaling overhead.

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 APPLICATION

This patent application claims priority to US Patent Application No. 10-2011-0001994, filed with South Korea on January 7, 2011, pursuant to Article 119 (a) (35 USC § 119 (a)). All content is incorporated by reference in this patent application. In addition, if this patent application claims priority to a country other than the United States for the same reason, all its contents are incorporated into this patent application by reference.

Claims (14)

1. A non-periodic reference signal receiving method by an aperiodic reference signal receiving apparatus in a wireless communication system using a plurality of component carriers (CC),

   Generating and transmitting downlink control information of a physical control channel including carrier element identification information of aperiodic reference signal;

   Receiving an aperiodic reference signal generated and transmitted by using the aperiodic CC identification information of the aperiodic reference signal and aperiodic reference signal configuration parameter information for each CC signaled separately;

   Aperiodic reference signal receiving method comprising a.
2. The method of claim 1,

   The aperiodic reference signal is an aperiodic sounding reference signal (hereinafter referred to as 'A-SRS'), and the transmission target identification information of the aperiodic reference signal is A-SRS transmission target CC identification information. A non-periodic reference signal receiving method characterized in that.
3. The method of claim 2,

   The A-SRS transmission target CC identification information is a bit information, characterized in that the aperiodic reference signal.
4. The method of claim 2,

   The physical control channel is a physical downlink control channel (PDCCH), and the downlink control information is DCI format 4 information, characterized in that the aperiodic reference signal receiving method.
5. The method of claim 2,

   The A-SRS configuration parameter information for each CC includes A-SRS configuration parameter set information for each of two or more CCs, and the A-SRS configuration parameter information for each CC is transmitted by RRC signaling. Signal reception method.
6. The method of claim 5,

   The A-SRS configuration parameter set includes SrsBandwidth (bandwidth information), FrequencyDomainposition (band position information), transmissionComb (transmission comb information), cyclic shift (cyclic shift information), number of antenna ports (antenna port number information) SrsHoppoingBandwidth (hopping) Bandwidth information), duration (period information) information comprising a.
7. The method of claim 2,

   The CC transmitting the A-SRS transmission target CC identification information is a primary component carrier (PCC) or a secondary component carrier (SCC), and the CC transmitting the A-SRS is a component carrier (SCC) other than the PCC and SCC. A non-periodic reference signal receiving method characterized in that.
8. An apparatus for receiving an aperiodic sounding reference signal (hereinafter referred to as 'A-SRS') in a wireless communication system using a plurality of component carriers (CC),

   An A-SRS transmission target CC identification information generation unit for generating A-SRS transmission target CC identification information for indicating a CC for transmitting the A-SRS among a plurality of CCs configured in the terminal;

   A DCI processing unit for generating downlink control information (DCI) including the generated A-SRS transmission target CC identification information;

   A PDCCH transmitter for transmitting the generated DCI to the UE through a physical control channel;

   An A-SRS receiver configured to receive an A-SRS transmitted by the terminal through the A-SRS transmission target CC determined as the A-SRS transmission target CC identification information;

   Aperiodic sounding reference signal receiving apparatus comprising a.
9. The method of claim 8,

   The CC-based A-SRS configuration parameter information processing unit for generating a CC-specific A-SRS configuration parameter information for use when transmitting a plurality of CCs configured in the terminal to transmit to the terminal by RRC signaling, characterized in that it further comprises Aperiodic sounding reference signal receiver.
10. The method of claim 8,

    A-SRS transmission target CC identification information included in the DCI is aperiodic sounding reference signal receiving apparatus, characterized in that the 2 bits information.
11. A method of transmitting an aperiodic sounding reference signal (hereinafter referred to as 'A-SRS') in a wireless communication system using a plurality of component carriers (CC),

    Receiving a DCI including the A-SRS transmission target CC identification information through a physical control channel

    Receiving A-SRS configuration parameter information to be used by an A-SRS transmission target CC through the separate higher level signaling;

    Determining an A-SRS transmission target CC to which an A-SRS is transmitted based on the A-SRS transmission target CC identification information;

    Determining an A-SRS configuration parameter set of an A-SRS transmission target CC based on the A-SRS configuration parameter information;

    Generating an A-SRS using the determined A-SRS configuration parameter set information and transmitting the A-SRS through the A-SRS transmission target CC;

    Aperiodic sounding reference signal transmission method comprising a.
12. An apparatus for transmitting an aperiodic sounding reference signal (hereinafter referred to as 'A-SRS') in a wireless communication system using a plurality of component carriers (CC),

    A DCI receiver configured to receive a DCI including the A-SRS transmission target CC identification information through a physical control channel;

    An RRC processing unit for receiving A-SRS configuration parameter information for each CC to be used by the A-SRS transmission target CC through RRC signaling;

    An A-SRS transmission target CC determination unit which determines an A-SRS transmission target CC to which the A-SRS is to be transmitted based on the A-SRS transmission target CC identification information;

    An A-SRS configuration parameter determiner for determining A-SRS configuration parameter information to be used by the A-SRS transmission target CC;

    An A-SRS transmitter for generating an A-SRS using the determined A-SRS configuration parameter information and transmitting the A-SRS through the A-SRS transmission target CC;

    Apparatus for aperiodic sounding reference signal comprising a.
13. The method of claim 12,

    The A-SRS transmission target CC identification information included in the DCI is 2-bit information, and the A-SRS configuration parameter information for each CC is table information including an A-SRS configuration parameter set for each of two or more CCs. Aperiodic sounding reference signal transmitter.
14. A method of transmitting and receiving an aperiodic sounding reference signal (hereinafter referred to as 'A-SRS') in a wireless communication system using a plurality of component carriers (CC),

    In the A-SRS receiving apparatus, A-SRS transmission target element carrier identification information is included in downlink control information (DCI) of the physical control channel and transmitted to the SRS transmitting apparatus.

    The SRS transmitting apparatus transmits the A-SRS through the A-SRS transmission target component carrier using the A-SRS transmission parameter information for each component carrier and the A-SRS transmission target component carrier identification information separately signaled from the physical control channel. Aperiodic sounding reference signal transmission and reception method, characterized in that.

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