KR101643226B1 - Method and apparatus of transmittingcontrol information - Google Patents

Abstract

A method for receiving control information from a terminal in a wireless communication system, the method comprising: transmitting a resource indicator for a demodulation reference signal (DM-RS) to a physical downlink control channel (DM- RS field, and mapping a resource indicator associated with the DM-RS to the control information according to a predetermined condition, the predetermined condition being indicative of a mapping of the DMRS and the control information in the PDCCH To a control information receiving method.

Description

[0001] METHOD AND APPARATUS OF TRANSMITTING CONTROL INFORMATION [0002]

The present invention relates to a method and apparatus for transmitting control information in a wireless communication system. More particularly, the present invention relates to a method and apparatus for transmitting control information using a demodulation reference signal (DM-RS) resource.

Background of the Invention [0002] Wireless communication systems are widely deployed to provide various types of communication services such as voice and data. Generally, a wireless communication system is a multiple access system capable of supporting communication with multiple users by sharing available system resources (bandwidth, transmission power, etc.). Examples of multiple access systems include a code division multiple access (CDMA) system, a frequency division multiple access (FDMA) system, a time division multiple access (TDMA) system, an orthogonal frequency division multiple access (OFDMA) system, a single carrier frequency division multiple access (MC-FDMA) system, and a multi-carrier frequency division multiple access (MC-FDMA) system. In a wireless communication system, a terminal can receive information from a base station through a downlink (DL), and a terminal can transmit information to a base station through an uplink (UL). The information transmitted or received by the terminal includes data and various control information, and various physical channels exist depending on the type and use of information transmitted or received by the terminal.

It is an object of the present invention to provide a method of transmitting control information effectively in a wireless communication system.

It is another object of the present invention to provide a method for performing efficient resource management by transmitting various control information through a DM-RS resource used in a wireless communication system.

It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory and are not restrictive of the invention, unless further departing from the spirit and scope of the invention as defined by the appended claims. It will be possible.

A method for receiving control information of a mobile station in a wireless communication system according to an embodiment of the present invention for solving the above-mentioned problems is characterized in that a resource indicator related to a demodulation reference signal (DM-RS) Receiving, via a DM-RS field of a physical downlink control channel, a resource indicator associated with the DM-RS according to a predetermined condition; Indicates whether or not information indicating a mapping of the DMRS and the control information is included in the PDCCH.

The control information receiving method according to an embodiment of the present invention may further include receiving DM-RS configuration information including the mapping rule for mapping the resource indicator related to the DM-RS to the control information from the base station .

Here, the predetermined condition may include a case where a specific field value in the DM-RS field is a predetermined value indicating the control information.

The DM-RS field includes a plurality of subfields, wherein a first subfield of the plurality of subfields indicates a type of the control information, and a second subfield indicates a value of the control information.

The control information may include DM-RS index information related to the operation control of the MIMO system. Alternatively, the control information may include downlink carrier indication information for feedback of information according to channel estimation. Alternatively, the control information may include uplink carrier indication information for resource allocation in uplink transmission. Alternatively, the control information may include information about a feedback transmission mode indicating a set of feedback information including at least one uplink control information to be feedback-transmitted at the terminal. Alternatively, the control information may include information about a change in a sounding reference signal (SRS) configuration to be transmitted to the repeater. Alternatively, the control information may include parameter information related to a CoMP system to be used in a Coordinated Multi-Point (CoMP) system. Alternatively, the control information may include piggybacking control information indicating a multicarrier transmission mode in which a signal can be transmitted using a control channel and a shared channel simultaneously, or a transmission mode for maintaining a single carrier priority. Alternatively, the control information may include indication information for distinguishing multiple MCS / TBS operations that may be used for uplink transmission. Alternatively, the control information may include indication information indicating a power control parameter for a plurality of transmission antennas.

According to another aspect of the present invention, there is provided a method for transmitting a reference signal to a terminal in a wireless communication system, the method comprising: receiving a plurality of demodulation reference signals (DM-RS) And transmitting the specific DM-RS to the BS through a Physical Uplink Shared Channel (PUSCH) among the plurality of DM-RSs, RS is selected in a first DM-RS set during data transmission and is selected in a second DM-RS set in case of transmission of specific control information, and the value of the specific control information is selected in the DM-RS set in the second DM- Can be mapped.

The control information receiving method according to another embodiment of the present invention further includes receiving DM-RS configuration information including a mapping rule for mapping the specific control information to a DM-RS in the second DM-RS set can do.

The control information may include information on the number of successfully decoded PDCCHs among physical downlink control channels (PDCCHs) received from the base station. Alternatively, the control information may include the number of physical antennas of the base station and the configuration information of the power amplifier that can be used independently and satisfy predetermined conditions through downlink signal measurement received from the base station. Alternatively, the control information includes indication information about the terminal capability required when the terminal enters the cell area, and the indication information about the terminal capability includes a number of available physical antennas of the base station, Configuration, a multiple-input multiple-output system, or information on multi-carrier performance. Alternatively, the control information may include indication information indicating a specific PUSCH to which data among the plurality of PUSCHs is picked back. Alternatively, the control information may include any one of intra-cell interference information on which the terminal is located, an acknowledgment signal on a signal received from the base station, and carrier integration triggering information.

According to another aspect of the present invention, there is provided a mobile communication system including a receiving module for receiving a radio signal, a transmitting module for transmitting a radio signal, And a processor for performing a control operation by mapping a resource indicator related to a demodulation reference signal (DM-RS) at regular times to control information according to a predetermined condition, wherein the DM-RS resource indicator is a physical downlink Wherein the predetermined condition indicates whether or not information indicating a mapping of the DMRS and the control information is included in the PDCCH, The DM-RS configured based on the information about the DM-RS configuration indicated by the -RS resource indicator is transmitted to the base station It can be performed to transfer.

It is to be understood that both the foregoing general description and the following detailed description of the present invention are exemplary and explanatory and are intended to provide further explanation of the present invention by those skilled in the art. And can be understood and understood.

According to embodiments of the present invention, various control information can be efficiently transmitted in a wireless communication system.

Also, according to embodiments of the present invention, various control information can be efficiently transmitted by reusing DM-RS resources for control information transmission.

It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory and are not restrictive of the invention, unless further departing from the spirit and scope of the invention as defined by the appended claims. It will be possible.

BRIEF DESCRIPTION OF THE DRAWINGS The accompanying drawings, which are included to provide a further understanding of the invention and are incorporated in and constitute a part of the specification, illustrate embodiments of the invention and, together with the description, serve to explain the principles of the invention.
1 is a diagram showing a network structure of an E-UMTS.
2 is a diagram showing the structure of a radio frame used in LTE.
3 is a diagram illustrating a physical channel in a LTE system and signal transmission using the same.
4 is a diagram showing a structure of a downlink sub-frame.
5 is a diagram showing a structure of an uplink subframe.
6 is a diagram illustrating an example of a process in which a base station transmits a reference signal through a downlink channel according to an embodiment of the present invention.
7 is a diagram illustrating an example of a process in which a base station transmits a reference signal on a downlink channel according to another embodiment of the present invention.
8 is a block diagram illustrating a base station and a terminal in which embodiments of the present invention can be performed.

The configuration, operation and other features of the present invention can be easily understood by the embodiments of the present invention described with reference to the accompanying drawings. Embodiments of the present invention may be used in various wireless access technologies such as CDMA, FDMA, TDMA, OFDMA, SC-FDMA, and MC-FDMA. CDMA can be implemented with radio technologies such as UTRA (Universal Terrestrial Radio Access) or CDMA2000. The TDMA may be implemented in a wireless technology such as Global System for Mobile communications (GSM) / General Packet Radio Service (GPRS) / Enhanced Data Rates for GSM Evolution (EDGE). OFDMA may be implemented with wireless technologies such as IEEE 802.11 (Wi-Fi), IEEE 802.16 (WiMAX), IEEE 802.20, and Evolved UTRA (E-UTRA). UTRA is part of the Universal Mobile Telecommunications System (UMTS). The 3rd Generation Partnership Project (3GPP) long term evolution (LTE) is a part of E-UMTS (Evolved UMTS) using E-UTRA. LTE-A (Advanced) is an evolved version of 3GPP LTE.

The following embodiments mainly focus on the case where technical features of the present invention are applied to a 3GPP system, but the present invention is not limited thereto.

Although the present invention is described based on LTE-A, the concepts and proposals of the present invention and embodiments thereof can be applied to other systems using multiple carriers (e.g., IEEE 802.16m system) without limitation.

1 is a diagram showing a network structure of an E-UMTS. E-UMTS is also referred to as an LTE system. Communication networks are widely deployed to provide various communication services such as voice and packet data.

Referring to FIG. 1, an E-UMTS network includes an Evolved Universal Terrestrial Radio Access Network (E-UTRAN), an Evolved Packet Core (EPC), and a User Equipment (UE). The E-UTRAN includes one or more base stations (eNode B) (eNB) 11 and one or more terminals 10 may be located in one cell. The Mobility Management Entity / System Architecture Evolution (MME / SAE) gateway 12 may be located at the end of the network and may be connected to an external network. The downlink refers to communication from the base station 11 to the terminal 10, and the uplink refers to communication from the terminal to the base station.

The terminal 10 is a communication device carried by a user and the base station 11 is a fixed station that generally communicates with the terminal 10. [ The base station 11 provides the terminal 10 with the user plane and the end point of the control plane. One base station 11 may be arranged for each cell. An interface for transmitting user traffic or control traffic may be used between the base stations 11. The MME / SAE gateway 12 provides the terminal 10 with an endpoint of session and mobility management functions. The base station 11 and the MME / SAE gateway 12 may be connected via the S1 interface.

The MME provides various functions including distribution of paging messages to base stations 11, security control, dormant mobility control, SAE bearer control, and encryption and integrity protection of non-connection layer (NAS) signaling. The SAE gateway host provides various functions including end-of-plane packet switching and user plane switching for terminal 10 mobility support. The MME / SAE gateway 12 is referred to herein simply as a gateway and includes both an MME and an SAE gateway.

A plurality of nodes may be connected between the base station 11 and the gateway 12 via the S1 interface. The base stations 11 may be interconnected via an X2 interface and neighboring base stations may have a mesh network structure with an X2 interface.

2 illustrates a structure of a radio frame used in LTE.

Referring to FIG. 2, the radio frame has a length of 10 ms (327200 * T _s ) and includes 10 equal-sized subframes. Each subframe has a length of 1 ms and includes two 0.5 ms slots. T _s represents the sampling time and T _s = 1 / (15 kHz * 2048) = 3.2552 * 0 ^-8 (about 33 ns). A slot includes a plurality of Orthogonal Frequency Division Multiplexing (OFDM) symbols in the time domain and a plurality of Resource Blocks (RBs) in the frequency domain. In an LTE system, one resource block includes 12 subcarriers * 7 (6) OFDM (or SC-FDMA) symbols. Frame structure types 1 and 2 are used for FDD and TDD, respectively. Frame structure type 2 includes two half-frames, each half-frame includes five sub-frames, a downlink piloting time slot (DwPTS), a guard period (GP) , And an uplink Piloting Time Slot (UpPTS). The structure of the above-described radio frame is merely an example, and the number / length of subframe, slot, or OFDM (or SC-FDMA) symbols can be variously changed.

3 illustrates a physical channel in a LTE system and signal transmission using the same.

When the terminal is turned on or newly enters a cell, the terminal performs an initial cell search operation such as synchronizing with the base station (S301). To this end, the terminal receives a primary synchronization channel (P-SCH) and a secondary synchronization channel (S-SCH) from a base station and synchronizes with the base station, Information can be obtained. Then, the terminal can receive the physical broadcast channel from the base station and acquire the in-cell broadcast information. Upon completion of the initial cell search, the UE receives more specific system information by receiving a Physical Downlink Control Channel (PDCCH) and a physical downlink control channel (PDSCH) according to the information on the PDCCH (S302).

On the other hand, if the base station is initially connected or there is no radio resource for signal transmission, the terminal can perform a random access procedure (RACH) on the base station (steps S303 to S306). To this end, the UE transmits a specific sequence through a Physical Random Access Channel (PRACH) (S303 and S305), and receives a response message for the preamble on the PDCCH and the corresponding PDSCH ( S304 and S306). In case of the contention-based RACH, a contention resolution procedure can be additionally performed.

The UE having performed the procedure described above transmits a PDCCH / PDSCH reception (S307) and a Physical Uplink Shared Channel (PUSCH) / Physical Uplink Control Channel (PUSCH) as general uplink / Control Channel: PUCCH) (S308).

The control information that the UE transmits to the Node B via the uplink or receives from the Node B includes a downlink / uplink ACK / NACK signal, scheduling request (SR) information, channel quality indicator (CQI) A precoding matrix indicator (PMI), a rank indication (RI), and the like. In the case of the 3GPP LTE system, the UE can transmit control information such as CQI / PMI / RI as described above through PUSCH and / or PUCCH.

4 is a diagram showing a structure of a downlink sub-frame.

Referring to FIG. 4, a subframe includes an L1 / L2 control information region for transmitting scheduling information and other control information, a data region for transmitting downlink data, . The control region starts from the first OFDM symbol of the subframe and includes one or more OFDM symbols. The size of the control area can be set independently for each subframe. Various control channels including PDCCH (Physical Downlink Control Channel) are mapped to the control area. The PDCCH is allocated to the first n OFDM symbols of the subframe as the physical downlink control channel. The PDCCH includes one or more Control Channel Elements (CCEs). The CCE includes nine neighboring Resource Element Groups (REGs). The REG includes four neighboring REs, excluding the reference signal. RE is a minimum resource unit defined by one subcarrier * one OFDM symbol.

5 illustrates a structure of an uplink subframe.

Referring to FIG. 5, a sub-frame 500 having a length of 1 ms, which is a basic unit of uplink transmission, is composed of two 0.5 ms slots 501. Assuming a length of a normal cyclic prefix (CP), each slot is composed of seven symbols 502, and one symbol corresponds to one SC-FDMA symbol. A resource block (RB) 503 is a resource allocation unit corresponding to 12 slots in the frequency domain and one slot in the time domain. The uplink subframe is divided into a data area 504 and a control area 505. The data area includes an uplink shared channel (PUSCH) and is used to transmit data signals such as voice and video. The control region includes an uplink control channel (PUCCH) and is used to transmit control information. The PUCCH includes an RB pair (RB pair) located at both ends of the data area on the frequency axis and hopping the slot to the boundary.

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Following the description of the DMRS, the DM-RS in the uplink sub-frame is mapped to 12 REs per resource block and transmitted. The number of cyclic shifts that can be used in the DM-RS sequence is defined differently according to the CP length, and the number of available cyclic shifts for the normal CP and the extended CP can be variously implemented.

However, regardless of the number of circular movements, circular movements are not all used. For data transmission and demodulation, only one cyclic shift is used to demodulate one rank or one layer for data transmission. In particular, when there is one power amplifier in the uplink transmission of the LTE system, this means that only Rank 1 transmission is possible. That is, when a resource corresponding to 12 sequences corresponding to a DM-RS is used based on one RB in the resource structure, up to 8 degrees of freedom may be actually used for DM-RS transmission Can be used. The UE may configure the DM-RS sequence to be used on the uplink channel according to the information indicated by the base station, or configure the DM-RS according to the DM-RS sequence circulation movement information shared by the base station and the UE to perform uplink transmission.

Accordingly, the base station can indicate through the PDCCH field that the terminal can use not only the eight degrees of freedom in DM-RS configuration, but also the degree of freedom used to transmit additional information. That is, the degree of freedom may be used to transmit additional information for uplink data transmission with other downlink / uplink control information.

Therefore, the present invention proposes a method of transmitting various control information using the degree of freedom in the LTE-A system. Hereinafter, a control information transmitting method will be described with DM-RS as an example of a reference signal.

One. My 1 Embodiment (Transmission of control information from the base station to the terminal)

In general, the BS transmits circular movement information on the uplink DM-RS to the UE on the PDCCH. The terminal receiving the data transmits a DM-RS together with data and / or control information through a PUSCH by configuring a predetermined uplink DM-RS according to the instruction information of the base station.

The present invention provides a method and a system for indicating an uplink DM-RS by directing an uplink DM-RS through a PDCCH in a base station, And then re-interpreted as control information according to the control information.

In general, the DM-RS field may use the downlink control information (DCI) format used in the existing LTE system. DCI format 0 is used to schedule the PUSCH.

6 is a diagram illustrating an example of a process in which a base station transmits control information through a downlink channel according to an embodiment of the present invention.

Referring to FIG. 6, the BS transmits DM-RS configuration information to the MS (S601). Here, the 'DM-RS configuration information' includes information on a mapping rule that the 'DM-RS resource indicator' transmitted by the base station through the PDCCH can be reinterpreted as control information.

The 'DM-RS resource indicator' may be defined as information about the number of times of the circular movement of the DM-RS sequence transmitted to the base station by the terminal or information reinterpreted as control information according to the mapping rule. For example, if 3 bits are allocated to the DM-RS resource indicator and set to '010', the legacy system interprets DM-RS as applying 3 cycles of DM-RS sequence through '101' can do. According to an embodiment of the present invention, the DM-RS resource indicator set to '010' may be re-analyzed to refer to any of the control information described below, Is a rule for interpreting the information represented by "

The mapping rule to the control information of the DM-RS resource indicator may be arbitrarily set by the base station and transmitted to the base station and / or the base station and / or the terminal.

Then, the base station transmits DM-RS indication information including the DM-RS resource indicator to the terminal (S602). The 'DM-RS indication information' refers to a first DM-RS resource indicator indicating a cyclic shift of a DM-RS to be transmitted to the base station by the UE, and / or a second DM-RS resource indicator that can be reinterpreted as control information Information. That is, the DM-RS indication information may include a plurality of DM-RS resource indicators according to the configuration type, and the number of bits allocated to the indication information may vary according to the number of indicators included.

In this step, the BS may select any one of various control information that can be transmitted through the DM-RS indicator, and map the DM-RS resource indicator to the DM-RS resource indicator. The control information that can be re-interpreted via the DM-RS resource indicator according to an embodiment of the present invention will be briefly described below.

In order to configure the DM-RS indication information, the BS considers the degree of freedom for the DM-RS in the entire sequence for DM-RS transmission, and determines the type of control information to be transmitted through the DM-RS resource, Can be configured.

The BS divides a field for transmitting DM-RS indication information (hereinafter, referred to as a DM-RS field) into a plurality of fields and outputs a DM-RS resource indicator indicating the DM-RS circular movement and / Or a DM-RS resource indicator that is reinterpreted as control information. In this case, the DM-RS resource indicator indicating the DM-RS circular movement can indicate the position or value of a new DM-RS to be configured in the UE.

The DM-RS field according to an embodiment of the present invention can be used for a downlink control command or an uplink control command as well as a field including a DM-RS resource indicator for DM-RS configuration used in an existing legacy system Lt; RTI ID = 0.0 > DM-RS < / RTI > resource indicator. For example, a DM-RS field including a plurality of subfields may be configured such that a first subfield of the plurality of subfields indicates a type of the control information, and a second subfield indicates a value of the control information .

Also, the DM-RS field segmentation can be selectively performed in the case of a complementary process added to determine the DM-RS index calculation. For example, if there is a higher layer configuration on the mapping table between the bit string and the DM-RS index or on the index that starts the DM-RS, the number of bits constituting the DM-RS resource indicator may be reduced, The segmentation process can be reduced.

Also, the usage amount of the DM-RS field may be changed according to the field configuration method considering the number of control information that can be transmitted through the DM-RS field among a plurality of predefined control information.

In step S603, the UE receiving the DM-RS indication information determines whether to re-interpret the DM-RS resource indicator included in the indication information as the control information according to the mapping rule previously set or transmitted from the base station (S603) .

At this time, if the DM-RS resource indicator is re-interpreted as control information, the UE can detect control information from the DM-RS resource indicator and perform a control operation according to the detected control information. In accordance with the transmitted control information, the terminal may perform a control operation to be instructed or perform an operation required for operation of the terminal (S604).

Alternatively, the DM-RS signal newly configured according to the DM-RS resource indicator may be transmitted to the base station through the PUSCH or the PUCCH as in the existing legacy system (S605).

Hereinafter, the control information that can be transmitted through the DM-RS indication information transmitted from the base station to the UE through the PDCCH is as follows.

One) MIMO  Motion control information

The DM-RS index can be used as the PMI indicator or rank information according to the position of the index assigned to the DM-RS.

2) The downlink carrier direction information for feeding back information according to the channel estimation

Since a carrier to be monitored by a UE may include multiple downlink carriers, the BS may use a DM-RS index to transmit control information indicating a carrier to be used for reporting channel measurement information. Alternatively, the DM-RS index may be used to indicate a downlink carrier ID in a terminal group space or cell-specific carrier space including one or more terminals. The DM-RS index and the downlink carrier may be mapped to one-to-one or one-to-many. The measurement carrier indicator may be defined as a bit (carrier bit or bitmap) that is newly allocated to the PDCCH. A field including the measured carrier indicator may be referred to as a Carrier Indication Field (CIF), and a separate CIF may be included in the PDCCH when the measured carrier indicator is transmitted.

Alternatively, the mapping between the DM-RS index and the downlink carrier index can be performed implicitly in terms of overhead, unlike the method of allocating a new bit by configuring CIF on the PDCCH. In this case, the bits included in the CIF can be utilized as a carrier index.

3) Uplink carrier indication for resource allocation

The uplink target carrier may be defined by DM-RS bit selection. According to an embodiment of the present invention, a carrier indicator may be transmitted for uplink resource allocation in an asymmetric carrier set through a DM-RS field. The carrier indicator may likewise be transmitted via the carrier indication field (CIF). 1 bit or 2 bits may be allocated to the uplink carrier indicator in consideration of the number of uplink simultaneous transmission carriers. Information on resource allocation may be applied implicitly in the DM-RS selection or explicitly applied to the divided bits of the DM-RS indication bit. The uplink carrier indication information indicates a target carrier for uplink transmission. The DM-RS indication information means that a subset of the DM-RS candidates is for a specific uplink carrier, and may be determined at the base station or predefined in the system configuration.

Meanwhile, additional bits included in the CIF can be used as a carrier index when implicitly transmitting uplink carrier indication information for resource allocation.

4) Feedback on uplink control feedback mode  Instruction information

Generally, in a legacy system operation, a UE can feedback-transmit feedback information including CQI, RI, and ACK / NACK information to a base station through one PUSCH according to channel measurement. In this case, when the number of pieces of information to be feedback-transmitted becomes large, it is inefficient to transmit all pieces of feedback information through one PUSCH.

Therefore, the base station determines one or more feedback information to be simultaneously transmitted through the PUSCH transmission, and outputs feedback mode indication information related to the feedback information set including the determined at least one feedback information to the DM-RS field Lt; / RTI > That is, when the control information that the UE desires to feedback-transmit is piggybacked on the shared channel, the feedback information can be controlled according to the base station indication transmitted on the DM-RS on the PDCCH.

The UE may transmit the feedback information through the PUCCH or the PUSCH and the PUCCH. The selected DM-RS may indicate the transmission mode (actual content) of the UCI in the piggybacked information.

5) Sounding  Reference signal operation instruction information

In a general LTE-A system, a UE can know changed SRS configuration information whenever a sounding reference signal (SRS) configuration is changed. On the other hand, relays do not know when the changed SRS configuration information is changed. In addition, a repeater that recognizes a change in the SRS configuration information needs to request change information. However, according to this relay operation, the uplink SRS configuration must be known in advance by the PDCCH information. For example, the SRS operation indication information may be transmitted via the DM-RS field in terms of the DM-RS index position. The SRS operation indication information may be included in the SRS configuration information such as the periodicity or the antenna configuration for the next SRS transmission. The SRS operation indication information may include precoding matrix indication (PMI) information, antenna number information used for simultaneous transmission, SRS position information, and SRS overhead information.

6) CoMP  Related parameters

A Coordinated Multi-Point (CoMP) system is a system for improving the throughput of a user at a cell boundary by applying an improved MIMO transmission in a multi-cell environment. The CoMP system can reduce inter-cell interference in a multi-cell environment. With the CoMP system, a UE can receive data jointly from a multi-cell base station. In addition, each base station can simultaneously support one or more MSs MS1, MS2,... MSK using the same radio frequency resource, thereby improving the performance of the system. Also, the base station can perform a space division multiple access (SDMA) method based on channel state information between the base station and the terminal.

In case of CoMP operation, the base station can control a subset of the corresponding CoMP cell set or a specific cell ID, and can transmit CoMP-related parameters such as the cell ID through the DM-RS field for control operation.

The CoMP related parameter information may be transmitted via the DM-RS field so that the corresponding CoMP measurement of a particular cell may be reported in the assigned resource. Also, the uplink CoMP operation may be enabled according to the DM-RS operation. In the case of the uplink CoMP operation, the base station can instruct the terminal in advance of information on a common virtual resource used for the reception mode or the CoMP reference signal transmission. That is, the base station can simultaneously transmit the root sequence index and the circular movement information of the CoMP cell set through the DM-RS field.

MIMO systems can be extended to CoMP systems by transmitting CoMP related parameter information.

7) Piggybacking  Control information ( piggybacking control information )

There is a first uplink transmission mode which is a legacy transmission mode for maintaining a single carrier priority in the LTE-A system and a second uplink transmission mode which is used for multicarrier transmission in which a control channel and a shared channel can be simultaneously transmitted.

In order to support these two modes of operation, it is required to define a method of indicating the transmission mode setting. For example, it is possible to define a transmission mode through upper layer signaling, or to transmit indication information indicating whether to perform piggybacking on the PDCCH.

However, since the transmission mode indication information is necessary when simultaneously transmitting the control information and the data, the transmission mode can be implicitly indicated. This indication information may be included in the DM-RS field and transmitted. Since the indication information can be defined as a DM-RS moving position, a specific DM-RS position means control channel piggybacking, and another position means that piggybacking is not performed.

8) MCS / TBS  Distinguishing direction information

If there are multiple MCS / TBS tables that can be used for uplink transmission, the MCS / TBS operation can be distinguished by measurement, and the MCS / TBS operation distinction can be indicated as upper layer signaling or direct indication on the PDCCH . The specific DM-RS index can be used as information for indicating the distinguished MCS / TBS by directly indicating the indication information with a predetermined bit or indicating the operation distinguishing indication information implicitly on the DM-RS index. The different MCS / TBS tables may be multiple sets of MCS / TBS, any subset or limited set of MCS / TBS.

9) Power control parameter

According to the current power control mechanism, it is necessary to indicate additional power control parameters for multiple transmit antennas. The added power control parameter may be used either at the antenna itself or at the power gain offset. For example, power control may be defined as an increase (one circular movement index) or a decrease (another index). As another example, the power control target may be defined as one cyclic shift (antenna / power amplifier 1), another cyclic shift (antenna / power amplifier 2), etc., separately defined for each cyclic shift.

2. Second Example  (Control information transmission from the terminal to the base station)

The terminal can construct and transmit a DM-RS based on the DM-RS indication information transmitted from the base station.

As described above, the DM-RS indicated in the PDCCH can be reused in another cyclic shift according to a higher layer signaling or a predetermined information mapping process which can be defined by a predetermined rule.

The terminal can select the DM-RS according to the control information desired to be transmitted. The set of DM-RSs used for DM-RS selection may be defined as the total number of cyclic shifts or defined as limited cyclic shifts defined explicitly / implicitly through higher layer signaling or specific. The cyclic shift set may include a DM-RS used in the legacy terminal or an unused cyclic shift not included in the mapping table. Therefore, when it is assumed that the total number of DM-RSs that can be arbitrarily selected based on the unused cyclic shift is Na (Na> 1), the terminal can select control information to be transmitted based on one or more DM-RSs among Na have.

7 is a diagram illustrating an example of a process in which a base station transmits a reference signal on a downlink channel according to another embodiment of the present invention.

Referring to FIG. 7, in step S701, the BS transmits DM-RS configuration information on a mapping rule, which can be used to re-interpret the DM-RS resource indicator as control information, to the terminal. The description thereof is the same as that described in step S601 in Fig. 6, so that the same explanation will be omitted for the sake of simplicity in this specification. The mapping rules for interpreting the DM-RS resource indicator as control information may be preset in the base station and / or the terminal, as opposed to transmitting in the base station.

Thereafter, the terminal can select a DM-RS to be transmitted (S702).

The DM-RS set includes a first set of DM-RSs to be selected for data transmission and a second set of DM-RSs that can be re-interpreted as control information. If the number of DM-RSs included in the second DM-RS set is Na (Na> 1), the second DM-RS set is composed of DM-RSs that the terminal can arbitrarily select based on unused cyclic movement. , The UE may select one or more DM-RSs among Na and transmit control information. The selected control information may be received from the base station in the previous step or may be mapped to the DM-RS according to a predetermined mapping rule. Then, the terminal transmits the DM-RS mapped to the selected control information to the base station (S703).

Then, the base station performs detection for the transmitted DM-RS (S704). At this time, when the detected DM-RS belongs to the unused DM-RS set, the base station maps or interprets the DM-RS detected according to the signaling or predetermined mapping rule as the control information. In the case of LTE, since four DM-RSs (specifically, cyclic shifts to the DM-RS sequences) out of the 12 DM-RSs that can be configured using one sequence belong to the unused DM-RS set, Bit information to the BS using the DM-RS.

Hereinafter, the control information that can be transmitted through the DM-RS is as follows.

One) DTX  Instruction information

The UE can receive a plurality of PDCCHs from the base station and transmit indication information indicating the number of received PDCCHs to the BS in the DM-RS field through the PUCCH or PUSCH. When the number of UE-selectable cyclic shifts (Na) of the DM-RS is greater than the number of downlink carriers combined, the UE selects the proper DM-RS cyclic shift among the Na sets, thereby detecting the number of successfully decoded PDCCHs To the base station.

The number of suitable DM-RSs selected by the UE may be defined as an offset value for a starting part or a cyclic shift value of an indicated index of the PDCCH. Here, the offset value may be defined as a value excluding one PDCCH from the number of received PDCCHs (offset value = number of PDCCH received-1).

2) random Access  And LTE -A terminal capability ( capability ) Instruction Information

The control information reported by the terminal to the base station may include, for example, the number of available physical antennas, the configuration of a power amplifier that can be used independently, and information on MIMO or multi-carrier performance. The information about the terminal capability may be required in an initial access procedure in which a terminal, such as a random access procedure, performs cell entry. In the existing LTE system, since there is a negotiation process (legacy negotiation process) for exchanging the terminal capability before the terminal is actually connected to the base station, the information about the terminal capability can be transmitted according to the existing negotiation process . A negotiation process for an LTE-A specific terminal capability in the absence of a new scheme for negotiation between the LTE-A terminal and the base station with respect to the terminal capability information (e.g., LTE-A specific terminal capability) Can be performed after the legacy negotiation step. In this case, a separate negotiation step for the terminal capability needs to be added, thereby adding latency at the time of terminal capability negotiation. Therefore, it is desirable to keep the number of steps required to perform the initial access procedure the same as the existing LTE, rather than adding a step for negotiating terminal capabilities.

The distinction between LTE and LTE-A terminals A first message for random access, a second message as a preamble response message, and a third message. For example, when the first message is used to distinguish the LTE terminal from the LTE-A terminal in the random access procedure, the LTE-A terminal allocates a preamble (first preamble) distinguished from the legacy preamble Second preamble) sequence can be used. Then, the base station can use the PDCCH differentiated from the PDCCH for the LTE preamble response message when transmitting the LTE-A preamble response message (second message). The PDCCH used for the second message transmission can be distinguished using a Random Access-Radio Network Temporary Identifier (RA-RNTI) for the LTE terminal and the LTE-A terminal. Then, the LTE-A terminal receives the random access response distinguished from the LTE-A base station, and in response thereto, reports information about the terminal capability to the third message by including the information on the terminal capability.

An LTE-A terminal capability, such as carrier aggregation capability, number of physical antennas, number of power amplifiers, and CoMP related capability, may be transmitted over a shared channel or a DM-RS index.

When transmitting the LTE-A capability on the shared channel, it may be necessary to allocate a different demodulation coding or other uplink grant than that used in the existing LTE random access message 3. For this, the PDCCH for the random access response may be configured differently from the existing LTE, or the random access response may be interpreted differently from the existing LTE according to the upper layer configuration. If there is a PDCCH for the LTE-A terminal separately, there is no need to define an implicitly distinct interpretation of the third message transmission. For example, the transmission format for the third message may be predefined and the transmission format (modulation and coding scheme) may be indicated by the PDCCH.

If there is no PDCCH defined separately for the LTE-A terminal, the LTE-A terminal can interpret the same RAR as in the existing LTE. Accordingly, the content of the third message transmitted by the LTE-A terminal may be different from the content of the third message transmitted by the legacy LTE terminal. Information to interpret RAR differently can be defined in the LTE-A system information. If the shared channel is not used for LTE-A capability transmission, information about the corresponding LTE-A terminal capability may be transmitted via the DM-RS loop transfer selection. That is, the number of available physical antennas, the configuration of the power amplifier that can be used independently, the MIMO, or the multicarrier performance can be indicated by a specific DM-RS selection in a possible DM-RS circular movement set.

The discrimination of the LTE terminal and the LTE-A terminal by the preamble means that the LTE-A terminal preamble (or the LTE-A terminal preamble) is allocated in the designated preamble sequence or unusable sequence range (limited by the parameter configuration of the first preamble group and the second preamble group) Lt; / RTI > If the preamble is not distinguished, the LTE-A base station may arbitrarily transmit another PDCCH so that the LTE-A terminal receives the transmitted PDCCH and operates differently from the LTE terminal. If an implied interpretation is applied, the associated indication information may be identified as clear indication information through the system information or may be identified in the base station version information, such as an LTE-A base station.

3) Scheduling Request Information

Considering the detection reliability of the scheduling request, the scheduling request information may be transmitted on the shared channel (e.g., PUSCH) via the DM-RS. That is, the UE may indicate a scheduling request (On / Off) state or another scheduling request (On / Off / buffer state) according to a specific circular movement selection.

4) Piggybacking  Information

In the case of LTE-A uplink transmission, the transmission signal may include a plurality of cluster signals. That is, the generated signal can be transmitted through a plurality of different regions (clusters) in a frequency band or an uplink carrier and carry different information at the same time, such as data or control information. In this case, the terminal may use a method of picking back control information on a resource concatenation or data. That is, the UE can select a single transmission band as a primary transmission band for signal transmission, encode another shared channel as a primary transmission band, or collect control signals and piggyback the selected common transmission band to a selected primary transmission band. Information about piggybacking or concatenation within that transmission band may be indicated by the DM-RS selected from the Na cyclic shifts.

5) Interference indicator ( Interference Indicator )

The LTE-A UE can report the interference occurring in the channel while transmitting the DM-RS through the PUSCH. The interference indicator may correspond to a particular downlink subband or total system bandwidth. In addition, the interference indicator may also indicate a downlink carrier index, which means that the corresponding carrier shows a minimum interference level or a maximum interference level.

On the other hand, the interfering indicator may also indicate a corresponding cell ID in a particular reporting cell set. If desired, the Na cycling movement selection may indicate a combination of the associated parameters, such as the interference indicator itself and the carrier ID or cell index.

6) ACK / NACK  Instruction information

The UE may indicate an ACK / NACK signal indicating whether the signals transmitted from the base station are acknowledged by the DM-RS circular movement selection. ACK / NACK puncturing according to the legacy scheme can be prevented when ACK / NACK is transmitted by including it in the DM-RS field among Na circulation moves. Or, ACK / NACK to be transmitted additionally using general ACK / NACK transmission method used in the legacy system is transmitted through the DM-RS field among Na circulation movements.

7) Carrier integration Triggering ( carrier aggregation triggering ) Information

If the LTE-A terminal wishes to change the carrier-integrated configuration, the terminal may transmit the carrier-integrated triggering indication information via the DM-RS field. In general, a terminal operates in a configured carrier integrated mode. However, if there is a need to change the carrier configuration due to low traffic load or high traffic load compared to the current carrier integration, a new carrier-integrated configuration can be initiated by selecting the DM-RS among the Na cyclic shifts.

8) Emergency indicator emergency indicator )

When in an unforeseeable or urgent situation, the terminal must transmit an indicator of an emergency to the base station via any route. One of the various methods of indicating an emergency in an LTE-A terminal is to transmit it via the DM-RS cyclic shift selection among the Na cyclic shifts via the DM-RS field.

As described above, the control information that the UE may arbitrarily select and transmit to the BS may be transmitted at least one time through the DM-RS field, and the indication information indicating the transmitted control information need not be separately signaled.

The base station can read the control information using the mapping rule based on the predetermined DM-RS indicator information with respect to the control information transmitted from the UE, and perform the control operation accordingly.

The embodiments of the present invention described above can be supported for MIMO operation. That is, each transmit antenna (port) may support each DM-RS, and the DM-RS used at each antenna (port) may be independently selected from a predefined cyclic shift set.

Alternatively, the DM-RS cyclic shift may be signaled / selected / defined only for one reference transmit antenna (port), and another DM-RS cyclic shift may be determined to be a predetermined offset from the reference DM-RS cyclic shift.

The DM-RS transmission may be associated with data traffic or may be transmitted without other symbols.

According to the second exemplary embodiment of the present invention, when the PUSCH is used, the UE transmits various control information through the DM-RS selection. When the control information is transmitted through the DM-RS field on the PUSCH, But only the DM-RS can be transmitted.

Further, in addition to the control information described in the above-described embodiments, other control information may be transmitted through the DM-RS, and the respective control information may be independently transmitted or grouped by separate signaling rather than DM-RS .

Hereinafter, a base station and a terminal capable of performing embodiments of the present invention will be described with reference to FIG.

8 is a block diagram illustrating a base station and a terminal in which embodiments of the present invention can be performed.

The terminal can operate as a transmitting apparatus in the uplink and as a receiving apparatus in the downlink. In addition, the base station may operate as a receiving apparatus in an uplink and operate as a transmitting apparatus in a downlink. That is, the terminal and the base station may include a transmitting apparatus and a receiving apparatus for transmitting information or data.

The transmitting apparatus and the receiving apparatus may include a processor, a module, a part and / or a means for performing embodiments of the present invention. In particular, the transmitting apparatus and the receiving apparatus may include a module (means) for encrypting a message, a module for interpreting an encrypted message, an antenna for transmitting and receiving a message, and the like.

Referring to FIG. 8, the left side shows a base station belonging to a DAS in the structure of a transmitting apparatus, and the right side shows a terminal entering a cell served by a DAS base station in the structure of a receiving apparatus. The transmitting apparatus and the receiving apparatus may include antennas 801 and 802, receiving modules 810 and 820, processors 830 and 840, transmitting modules 850 and 860, and memories 870 and 880.

The antennas 801 and 802 include a receiving antenna for receiving a radio signal from the outside and transmitting the received radio signal to the receiving modules 810 and 820 and a transmitting antenna for transmitting signals generated from the transmitting modules 850 and 860 to the outside . The antennas 801 and 802 may be provided with two or more antennas when a multi-antenna (MIMO) function is supported.

The receiving modules 810 and 820 can decode and demodulate the radio signal received from the outside through the antenna and restore the original data to the processors 830 and 840. The receiving module and the antenna may be represented as a receiving unit for receiving a radio signal without separation as shown in FIG.

Processors 830 and 840 typically control the overall operation of the transmitting or receiving device. In particular, a controller function, a service characteristic, and a MAC (Medium Access Control) frame variable control function, a handover function, an authentication and encryption function, and the like are performed to perform the embodiments of the present invention .

Transmission modules 850 and 860 may perform predetermined coding and modulation on data to be transmitted from the processors 830 and 840 to be transmitted to the outside and then transmit the data to the antennas. The transmission module and the antenna may be represented as a transmission unit for transmitting a radio signal without separation as shown in FIG.

The memories 870 and 880 may store a program for processing and controlling the processors 830 and 840 and may store input / output data (UL grant, System information, a station identifier (STID), a flow identifier (FID), an operation time, and the like.

The memories 870 and 880 may be a flash memory type, a hard disk type, a multimedia card micro type, a card type memory (e.g., SD XD memory, etc.), a random access memory (RAM), a static random access memory (SRAM), a read-only memory (ROM), an electrically erasable programmable read-only memory (EEPROM), a programmable read- ), A magnetic memory, a magnetic disk, and / or an optical disk.

The processor 830 of the transmitting apparatus performs an overall control operation on the base station and performs at least one of control information to be transmitted to each terminal according to the embodiment of the present invention described above with reference to FIG. To be transmitted through the indication information for the demodulation reference signal (DM-RS) to be used.

Specifically, the processor 830 of the transmitter transmits 'DM-RS configuration information', which includes information on the mapping rules used to re-interpret the indicator indicating the cyclic movement of the DM-RS sequence used in the legacy system, And transmit it to the receiving apparatus through the transmitting module 850. [ Also, 'DM-RS indication information' including a DM-RS resource indicator indicating the cyclic movement information for the DM-RS to be configured in the receiving apparatus and / or a DM-RS resource indicator which can be reinterpreted as control information is configured And transmit it to the receiving device through the transmitting module 850.

In addition, as described above with reference to FIG. 7, control information can be derived based on the DM-RS transmitted from the receiving apparatus to perform a control operation.

The processor 840 of the receiving apparatus performs the overall control operation of the terminal. 6, a DM-RS used for channel measurement is configured on the basis of the DM-RS indication information transmitted from the transmitting apparatus through the receiving module 820, and is transmitted to the transmitting module 860, Or re-interprets the DM-RS indication information as control information, and performs the control operation accordingly.

In addition, according to the embodiment of the present invention described above with reference to FIG. 7, the DM-RS field may be included in one or more DM-RS fields of the control information to be transmitted by the UE based on the DM-RS field space information transmitted from the BS, have.

The processors 830 and 840 may be configured to transmit the respective control information described above in the embodiments of the present invention via separate signaling rather than DM-RS. The base station includes a controller function for performing the above-described embodiments of the present invention, orthogonal frequency division multiple access (OFDMA) packet scheduling, time division duplex (TDD) packet scheduling and channel multiplexing , MAC frame variable control function according to service characteristics and propagation environment, high speed traffic real time control function, handover function, authentication and encryption function, packet modulation / demodulation function for data transmission, high speed packet channel coding function and real time modem control function Etc. may be performed through at least one of the modules described above, or may include additional means, modules, or portions for performing such functions.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The foregoing description of the preferred embodiments of the invention disclosed herein has been presented to enable any person skilled in the art to make and use the present invention. While the present invention has been particularly shown and described with reference to preferred embodiments thereof, it will be understood by those skilled in the art that various changes and modifications may be made therein without departing from the spirit and scope of the invention as defined by the appended claims. For example, those skilled in the art can utilize each of the configurations described in the above-described embodiments in a manner of mutually combining them.

Accordingly, the present invention is not intended to be limited to the embodiments shown herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims (21)

A method for a terminal to receive control information in a wireless communication system,
Receiving a resource indicator for a demodulation reference signal (DM-RS) from a base station through a DM-RS field of a physical downlink control channel; And
And mapping the resource indicator related to the DM-RS to the control information according to a predetermined condition,
Wherein the predetermined condition indicates whether information indicating a mapping of the DM-RS and the control information is included in the PDCCH. The method according to claim 1,
Further comprising the step of receiving DM-RS configuration information including a mapping rule mapping the resource indicator related to the DM-RS from the base station to the control information. The method according to claim 1,
Wherein the predetermined condition includes a case where a specific field value in the DM-RS field is a predetermined value indicating the control information. The method of claim 3,
The DM-RS field includes a plurality of subfields,
Wherein a first subfield of the plurality of subfields indicates a type of the control information and a second subfield indicates a value of the control information. The method according to claim 1,
Wherein the control information comprises DM-RS index information associated with operation control of the MIMO system. The method according to claim 1,
Wherein the control information includes downlink carrier indication information for feeding back information according to channel estimation. The method according to claim 1,
Wherein the control information comprises uplink carrier indication information for allocating resources in an uplink transmission. The method according to claim 1,
Wherein the control information includes information on a feedback transmission mode indicating a feedback information set including one or more uplink control information to be feedback-transmitted in the terminal. The method according to claim 1,
Wherein the control information includes information about a change in a sounding reference signal (SRS) configuration to be transmitted to a repeater. The method according to claim 1,
Wherein the control information includes parameter information related to a CoMP system to be used in a Coordinated Multi-Point (CoMP) system. The method according to claim 1,
Wherein the control information includes piggybacking control information indicating a multicarrier transmission mode in which a signal can be transmitted using a control channel and a shared channel simultaneously or a transmission mode for maintaining a single carrier priority. A method for receiving control information. The method according to claim 1,
Wherein the control information includes indication information for distinguishing between multiple MCS / TBS operations that can be used for uplink transmission. The method according to claim 1,
Wherein the control information includes indication information indicating a power control parameter for a plurality of transmission antennas. A method for transmitting a reference signal by a terminal in a wireless communication system,
Receiving information for identifying a plurality of demodulation reference signals (DM-RSs) from a base station; And
Transmitting a specific DM-RS from the plurality of DM-RSs to the BS through a Physical Uplink Shared Channel (PUSCH)
The particular DM-RS is selected in the first DM-RS set for data transmission and in the second DM-RS set for specific control information transmission,
Wherein the value of the specific control information is mapped to a DM-RS in the second set of DM-RSs. 15. The method of claim 14,
Further comprising receiving DM-RS configuration information including a mapping rule for mapping the specific control information to a DM-RS in the second DM-RS set. 15. The method of claim 14,
Wherein the specific control information includes information on the number of successfully decoded PDCCHs among physical downlink control channels (PDCCHs) received from the base station. 15. The method of claim 14,
Wherein the specific control information includes the number of physical antennas of the base station and the configuration information of the power amplifier that satisfy predetermined conditions through downlink signal measurement received from the base station and can be used independently. 15. The method of claim 14,
Wherein the specific control information includes indication information about a capability of the terminal requested when the terminal enters the cell area,
Wherein the indication information on the terminal capability includes information on the number of available physical antennas of the base station, a configuration of a power amplifier that can be used independently, and a multi-input multiple output system or multicarrier performance. 15. The method of claim 14,
Wherein the specific control information includes indication information indicating a specific PUSCH to which data among a plurality of PUSCHs are piggybacked. 15. The method of claim 14,
Wherein the control information includes any one of intra-cell interference information on which the terminal is located, an acknowledgment signal on a signal received from the base station, and carrier integration triggering information. In a wireless communication system,
A receiving module for receiving a wireless signal;
A transmission module for transmitting a radio signal; And
And a processor for performing a control operation by mapping a resource indicator related to a demodulation reference signal (DM-RS) received from the base station through the reception module to control information according to a predetermined condition,
The DM-RS resource indicator is received through a DM-RS field of a physical downlink control channel,
Wherein the predetermined condition indicates whether information indicating a mapping of the DM-RS and the control information is included in the PDCCH,
Wherein the processor is configured to transmit the DM-RS configured based on the information about the DM-RS configuration indicated by the DM-RS resource indicator to the base station through the transmission module.

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