WO2013168976A1

WO2013168976A1 - Transmission end, terminal, csi-rs transmission subframe signaling method, and csi-rs transmission subframe checking method

Info

Publication number: WO2013168976A1
Application number: PCT/KR2013/003978
Authority: WO
Inventors: 윤성준; 안재현
Original assignee: 주식회사 팬택
Priority date: 2012-05-11
Filing date: 2013-05-07
Publication date: 2013-11-14
Also published as: KR20130126353A

Abstract

The present invention relates to an apparatus and method for enabling a terminal to receive a reference signal for channel measurement from a plurality of transmission ends in a coordinated multipoint (CoMP) environment in which the terminal may communicate with the plurality of transmission ends.

Description

Transmitter, UE, CSI-RS transmission subframe signaling method, and CSI-RS transmission subframe confirmation method

The present invention relates to an apparatus and method for allowing a terminal to receive a reference signal for channel measurement from a plurality of transmission terminals in a CoMP (Coordinated Multi-Point) environment in which the terminal can communicate with a plurality of transmission terminals.

As communication systems have evolved, consumers, such as businesses and individuals, have used a wide variety of wireless terminals. Mobile communication systems such as LTE (Long Term Evolution) and LTE-A (LTE Advanced) of the current 3GPP series are high-speed and large-capacity communication systems that can transmit and receive various data such as video and wireless data, beyond voice-oriented services. Therefore, there is a demand for developing a technology capable of transmitting a large amount of data corresponding to a wired communication network. As one method for transmitting a large amount of data, a method (CoMP (Coordinated Multi-Point)) may be used in which a plurality of transmitters cooperate to communicate with a terminal.

In order to measure the downlink channel so as to efficiently perform the downlink communication, a channel status information reference signal (CSI-RS), which is a reference signal for measuring the downlink channel, may be transmitted from a transmitting end. When the terminal communicates with a plurality of cooperative transmission terminals, it is necessary to measure the downlink channel for each transmission terminal, and thus the terminal should receive the CSI-RS transmitted from the plurality of transmission terminals.

In order to receive the CSI-RS transmitted from the transmitter, the UE receives configuration information on the CSI-RS from the transmitter. The configuration information includes CSI-RS transmission subframe information indicating a subframe in which the CSI-RS is transmitted. However, in some subframes among the CSI-RS transmission subframes, the CSI-RS may not be transmitted to avoid collision with a channel or a signal used for another purpose. In an environment in which a plurality of transmitting terminals cooperate to communicate with a terminal, the terminal should be able to identify a subframe in which the CSI-RS is not transmitted in order to avoid signal collisions not only with the transmitting terminal to which the terminal belongs but also with other transmitting terminals.

An object of the present invention is to provide an apparatus and method for allowing a terminal to receive a reference signal for channel measurement from a plurality of transmission terminals in a CoMP (Coordinated Multi-Point) environment in which the terminal can communicate with a plurality of transmission terminals. It is done.

According to an embodiment of the present invention, in a system in which one terminal can communicate in cooperation with a plurality of transmission terminals, the transmission terminal is represented by a period and an offset and a CSI-RS (Channel Status Information-Reference Signal) is transmitted. A parameter setting unit for generating a parameter indicating subframes in which CSI-RSs are actually transmitted and / or subframes in which CSI-RSs are not actually transmitted among the scheduled CSI-RS transmission subframes; And a transmitter for transmitting the generated parameter to the terminal.

Another embodiment of the present invention is a terminal capable of communicating in cooperation with a plurality of transmission terminals, which are represented by a period and an offset and are scheduled to transmit CSI-RS (Channel Status Information-Reference Signal) CSI-RS transmission subframes A parameter receiver configured to receive a parameter indicating subframes in which CSI-RSs are actually transmitted and / or subframes in which CSI-RSs are not actually transmitted; And a subframe checking unit for checking subframes in which the CSI-RS is actually transmitted using the received parameter.

According to another embodiment of the present invention, in a system in which one terminal communicates with a plurality of transmission terminals, a method for signaling a CSI-RS transmission subframe by a transmission terminal includes a period and Among the CSI-RS transmission subframes in which the CSI-RS is expected to be transmitted and expressed as an offset, a parameter is generated that indicates subframes in which the CSI-RS is actually transmitted and / or subframes in which the CSI-RS is not actually transmitted. step; And it provides a CSI-RS transmission subframe signaling method comprising the step of transmitting the parameter to the terminal.

Another embodiment of the present invention is a method in which a terminal identifies a channel status information-reference signal (CSI-RS) transmission subframe in a system in which one terminal communicates with a plurality of transmission terminals. Receiving a parameter indicating subframes in which CSI-RSs are actually transmitted and / or subframes in which CSI-RSs are not actually transmitted among CSI-RS transmission subframes in which CSI-RSs are expected to be transmitted. ; And identifying subframes in which the CSI-RS is actually transmitted using the parameter.

According to the present invention described above, in a CoMP (Coordinated Multi-Point) environment in which a terminal may communicate with a plurality of transmission terminals, the terminal may receive a reference signal for channel measurement from the plurality of transmission terminals.

1 illustrates an example of a wireless communication system in which a terminal communicates with one transmission terminal.

2 illustrates an example of a wireless communication system in which a terminal communicates with a plurality of transmission terminals.

3 is a flowchart illustrating a CSI-RS transmission subframe signaling method according to an embodiment.

4 is an exemplary diagram for describing a bitmap transmitted through higher layer signaling.

5 is a flowchart illustrating a CSI-RS transmission subframe signaling method according to another embodiment.

6 is an exemplary diagram for describing a bit value transmitted through higher layer signaling.

7 is a block diagram illustrating a configuration of a transmission terminal according to an embodiment.

8 is a block diagram illustrating a configuration of a terminal according to an embodiment.

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 an example of a wireless communication system in which a terminal communicates with one transmitting end (eg, a base station).

Referring to FIG. 1, a wireless communication system includes a user equipment (UE) 10 and a transmission point (TP) 20 that performs uplink and downlink communication with the terminal 10.

In the present specification, the terminal 10 is a comprehensive concept of a terminal in wireless communication. In addition, a user station (UE) in WCDMA, LTE, HSPA, etc., as well as a mobile station (MS) and user terminal (UT) in GSM It should be interpreted as a concept including a subscriber station (SS), a wireless device, and the like.

The transmitting end 20 may be a base station (BS), which is generally a station for communicating with the terminal 10, and includes a node-B, an evolved node-B, and a sector ( Other terms may be referred to as a sector, a site, a base transceiver system (BTS), an access point, a relay node, and the like.

In addition, the transmission stage 20 is meant to cover all of the various coverage areas, such as megacell, macrocell, microcell, picocell, femtocell, radio resource head (RRH) and relay node communication range.

In order to check the downlink channel status, the transmitter 20 may transmit a channel status information reference signal (CSI-RS) which is a reference signal for channel status information. The terminal 10 may receive the CSI-RS, measure channel status, and transmit a channel status report.

Information on the period and offset of the timing (subframe) at which the transmitter 20 transmits the CSI-RS may be transmitted to the terminal 10 through higher layer signaling. Table 1 below shows a configuration for a subframe in which a CSI-RS transmitted through a higher layer is transmitted.

TABLE 1

The I _CSI-RS is a value transmitted from the transmitting terminal 20 to the terminal 10 through higher layer signaling such as RRC (Radio Resource Control), and may have a value of 0 to 154 with an size of 8 bits. The T _CSI-RS is a value representing the period in which the CSI-RS is transmitted in subframe units and may be 5, 10, 20, 40, or 80 subframes. Δ _CSI-RS is a value indicating an offset of a subframe in which the CSI-RS is transmitted in subframe units. T _CSI-RS and Δ _CSI-RS may be determined by ICSI-RS delivered through a higher layer.

Even in a subframe configured to transmit the CSI-RS through the higher layer signaling, the CSI-RS may not be transmitted in the next subframe.

A. In the case of a frame structure type (FS) 2, that is, a time division duplex (TDD), the CSI-RS is not transmitted in a special subframe. The special subframe may exist at subframe index # 1 or at subframe indexes # 1 and # 6 in one radio frame (consisting of 10 subframes), and a subframe in which uplink and downlink transmission exist simultaneously. to be. The special subframe may be configured in a 5 ms (5 subframe) or 10 ms (10 subframe) period.

B. CSI-RS is not transmitted in case of subframe where CSI-RS transmission collides with Primary Synchronization Signal (PSS) / Secondary Synchronization Signal (SSS), Physical Broadcast CHannel (PBCH), or System Information Block 1 (SIB1) message. Do not.

PSS: FS 1, ie, in case of Frequency Division Duplex (FDD), is transmitted in subframe indexes # 0 and # 5, and in FS 2 (TDD), it is transmitted in subframe indexes # 1 and # 6. That is, it may be configured in a 5 ms (5 subframe) period.

SSS: transmitted in subframe indexes # 0 and # 5. That is, it may be configured in a 5 ms (5 subframe) period.

PBCH: transmitted in subframe index # 0. The PBCH is configured in 40 ms (40 subframe) periods, but is divided and mapped four times in one period. Therefore, each divided PBCH within a 40 ms period may be mapped and transmitted at subframe index # 0 every 10 ms (10 subframes).

SIB1: SIB1 is a subframe index of the SFN (specific radio frame) when a value obtained by modularly calculating a SFN (which may correspond to an index of a radio frame) to 8 (SFN mod 8) is 0. In # 5, it is transmitted through PDSCH (Physical Downlink Shared CHannel). That is, it may be configured as a period of 80 ms (80 subframes).

A. A CSI-RS is not transmitted in a subframe configured for transmission of a paging message. In the case of FS 1 (FDD), it is transmitted at subframe indexes # 0, # 4, # 5, or # 9 of a specific SFN at intervals of 32, 64, 128, or 256 SFNs. In the case of FS 2 (TDD), it is transmitted in subframe indexes # 0, # 1, # 5, or # 6 of a specific SFN at intervals of 32, 64, 128, or 256 SFNs. That is, it may consist of a period of 320 ms (320 subframes), 640 ms (640 subframes), 1280 ms (1280 subframes), or 2560 ms (2560 subframes).

The terminal 10 communicating with one transmitting end may know which subframe among the subframes scheduled to transmit the CSI-RS will not be transmitted. That is, the terminal 10 transmits a special subframe, a subframe in which a special subframe, a CSI-RS and a PSS, an SSS, a PBCH, or an SIB1 collide by information transmitted through higher layer signaling or a predefined rule, and a paging message is transmitted. Knowing subframes are known. The terminal 10 may know that the CSI-RS is not transmitted in these subframes.

On the other hand, in order to increase the communication efficiency of the communication network, the terminal receives information from a plurality of transmission terminals at the same time, or a plurality of transmission terminals are controlled by the same scheduler (scheduler) while transmitting information to the same terminal through the cooperative communication The use of coordinated multi-point (CoMP) wireless communication systems is being considered.

2 illustrates an example of a CoMP system in which a terminal communicates with a plurality of transmission terminals.

In the example of FIG. 2, the terminal 10 communicates with a plurality of transmission terminals 20 -A and 20 -B. The CoMP system shown in FIG. 2 is a homogeneous network in which a plurality of transmission terminals 20 -A and 20 -B have the same or similar level of coverage area (eg, a plurality of macro base stations), or The plurality of transmission terminals 20 -A and 20 -B may be a heterogeneous network having different levels of coverage area (eg, macro base station and RRH). The plurality of transmission terminals 20 -A and 20 -B may have the same or different cell IDs.

In the example of FIG. 2, the terminal 10 uses a cell of the transmitting end 20 -A as a serving cell and communicates with the transmitting ends 20 -A and 20 -B. For channel state measurement for downlink communication, the terminal 10 receives the CSI-RS A from the transmitting end 20-A and receives the CSI-RS B from the transmitting end 20-B. The configuration information for the CSI-RS A and the CSI-RS B may be all transmitted from the transmitting end 20-A, or may be transmitted from the transmitting end 20-A and the transmitting end 20-B, respectively. However, the configuration information for each of the CSI-RS (for example, CSI-RS A, CSI-RS B) is transmitted from the serving cell (for example, the transmitter 20-A) to which the UE belongs. It is common to be. In this case, the configuration information may be transmitted through higher layer signaling such as RRC. Parameters transmitted through higher layer signaling for CSI-RS configuration include information on CSI-RS transmit antenna ports (antennaPortsCount) (2 bits in total) and information on CSI-RS resources (resourceConfig) (5 bits in total). It may include information on the CSI-RS transmission subframe (subframeConfig) (8-bit value in total), information on the CSI-RS transmission power (Pc), and the like. In addition, when generating a sequence for the CSI-RS in a CoMP environment, a virtual cell ID (X) (9-bit total value) that may be used instead of the cell ID may be included in configuration information delivered through higher layer signaling. The transmitter 20-A transmits both information related to the CSI-RS A transmitted from the transmitter 20-A and information related to the CSI-RS B transmitted from the transmitter 20-B through higher layer signaling. I can deliver it.

In this case, since the terminal 10 belongs to the transmission terminal 20 -A, the terminal 10 includes a time point (for TDD) at which a special subframe of the transmission terminal 20 -A is configured, PSS / SSS, PBCH, When the subframe for the transmission of the SIB1 message or the like is configured, and when the subframe for the transmission of the paging message is configured. However, since the terminal 10 does not belong to the transmission terminal 20 -B, the terminal 10 includes a time point at which a special subframe of the transmission terminal 20 -B is configured (for TDD), PSS / SSS, and PBCH. , When the subframe for the transmission of the SIB1 message, etc. is configured, and when the subframe for the transmission of the paging message is configured.

If the setting of the transmitting end 20-A and the setting of the transmitting end 20-B are related, the terminal 10 sets the setting of the transmitting end 20-B from the setting of the transmitting end 20-A. It may be possible to infer. However, even when the setting of the transmitting end 20-A and the setting of the transmitting end 20-B are related, the transmission subframe of the transmitting end 20-A and the subframe of the transmitting end 20-B are related. When this synchronization is not in place, analogy can be difficult.

Accordingly, a method for allowing the terminal 10 to know not only the cell to which it belongs but also a subframe that does not transmit CSI-RS caused by another cell or a transmitting end to which it does not belong may be required.

3 is a flowchart illustrating a CSI-RS transmission subframe signaling method according to an embodiment of the present invention.

Referring to FIG. 3, the transmitting terminal 20-A to which the terminal 10 belongs transmits a parameter for CSI-RS configuration through higher layer signaling such as RRC (Radio Resource Control) (S310). The parameter for CSI-RS configuration may be set for each of one or more transmission terminals that may communicate with the terminal or may communicate with the terminal, and may be delivered to the terminal. That is, in the example of FIG. 2, the parameters for setting the CSI-RS are the parameters for setting the CSI-RS of the transmitting terminal 20-A to which the terminal belongs and the CSI-RS of the transmitting terminal 20-B to which the terminal does not belong. Contains parameters for configuration.

Parameters for configuring the CSI-RS include the above-described information on the CSI-RS transmission antenna port (antennaPortsCount), information on the CSI-RS resource (resourceConfig), information on the CSI-RS transmission subframe (subframeConfig), CSI-RS Information Pc about transmit power, and a virtual cell ID (X) that can be used for CSI-RS sequence generation.

In addition, the parameter for configuring the CSI-RS indicates a subframe in which the CSI-RS is not transmitted by the CSI-RS or the like by a special subframe, PSS / SSS, PBCH, SIB1, or paging message among the CSI-RS transmission subframes. It may include a bitmap. The bitmap may be configured with a CSI-RS transmission period (P _A ) (5, 10, 20, 40, or 80 subframes) as one bit value, and actually for each CSI-RS transmission period, the CSI-RS May indicate whether the subframe is transmitted or not. The bitmap may have a configuration period of bitmap information of 'P _B ' and may be configured of the number of bits of P _B / P _A.

In the example of FIG. 4, the period P _A of the CSI-RS transmission subframe is 40 ms (40 subframes) based on the information (subframeConfig) (I _CSI-RS in Table 1) for the CSI-RS transmission subframe. Is determined. On the other hand, the bitmap information construction period (P _B ) is assumed to be 320 ms (320 subframes) as a value transmitted or previously set by higher layer signaling. In this case, the bitmap may consist of 8 (= P _B / P _A ) bits.

Of the eight CSI-RS transmission subframes, the subframe in which the CSI-RS is actually transmitted is 0 and the subframe in which the CSI-RS is not transmitted is 1, or the subframe in which the CSI-RS is transmitted is 1, and the CSI-RS is transmitted. A subframe in which no RS is transmitted may be zero.

In the example of FIG. 4, a second CSI-RS transmission subframe period (CSI-RS transmission period index # 1) and a sixth CSI-RS transmission period (CSI-RS transmission period index) of eight CSI-RS transmission subframe periods. If the CSI-RS transmission subframe belonging to # 5) is a subframe in which CSI-RS is not actually transmitted by a special subframe, PSS / SSS, PBCH, SIB1, paging message, etc., the bitmap consists of '01000100'. Can be.

In a first example, the bitmap information construction period P _B may be a predefined value. When the period P _A of the CSI-RS transmission subframe is determined based on the information (subframeConfig) for the CSI-RS transmission subframe, the number of bits of the bitmap will be P _B / P _A. In this example, the number of bits of the bitmap may be changed according to the period P _A of the CSI-RS transmission subframe.

For example, the bitmap information construction period P _B is 160 ms, 320 ms, 640 ms, 1280 ms, or 2, which is an exponential multiple of 2 of the CSI-RS transmission period P _A , where ⁱ and i are integers. It may be one of 2560 ms, but is not limited thereto. In one example, the bitmap information configuration period P _B is preset to 320 ms, and the period P _A of the CSI-RS transmission subframe is based on the information about the CSI-RS transmission subframe (subframeConfig). When determined to be 40 ms, the bitmap may have a size of 8 (= P _B / P _A ) bits and indicate whether or not the CSI-RS is actually a subframe for each CSI-RS transmission subframe.

In a second example, the number of bits P _B / P _{A of the} bitmap may be a predefined value. When the period P _A of the CSI-RS transmission subframe is determined based on the information (subframeConfig) for the CSI-RS transmission subframe, the bitmap information configuration period will be P _B. In this example, the bitmap information configuration period may be changed according to the period P _A of the CSI-RS transmission subframe.

For example, the number of bits in the bitmap may be one of 2, 4, 8, 16, or 32 as an exponential multiple of 2 (2 ⁱ , i is an integer). In one example, when the number of bits of the bitmap is preset to 8 and the period P _A of the CSI-RS transmission subframe is determined to be 40 ms based on the information (subframeConfig) for the CSI-RS transmission subframe. The bitmap information configuration period P _B may be 320 ms. Thus, for each CSI-RS transmission subframe with a period of 320 ms, it may be indicated whether or not the CSI-RS is a subframe in which the CSI-RS is actually transmitted.

In a third example, information about the number of bits P _B / P _A of the bitmap may be delivered through higher layer signaling. When the period P _A of the CSI-RS transmission subframe is determined based on the information (subframeConfig) for the CSI-RS transmission subframe, the bitmap is based on the number of bits of the bitmap and the period of the CSI-RS transmission subframe. The information composition cycle can be calculated. In this example, the bitmap information configuration period may be changed according to the information about the period P _A of the CSI-RS transmission subframe and the number of bits of the bitmap.

For example, the number of bits in a bitmap is a value that is an exponential multiple of 2 (2 ^{i + j} ), i is a predetermined value as a natural number of 1 or more, and j is an integer of 0 to k, which is conveyed through higher layer signaling. May be a value. In this case, the number of bits of the bitmap may have a value of 2 ⁱ , 2 ^{i + 1} , 2 ^{i + 2} , ..., 2 ^{i + k-1} , or 2 ^{i + k} , and the period of constructing the bitmap information (P _B ) may have a value of 2 ⁱ P _A , 2 ^{i + 1} P _A , 2 ^{i + 2} P _A , ..., 2 ^{i + k-1} P _A , or 2 ^{i + k} P _A . To specify the number of bits (or bitmap information construction period) of the bitmap, the value of j may be delivered through higher layer signaling, and the number of bits for indicating j value may be

Can be.

For example, when i = 1, k = 3, the bitmap information construction period P _B is twice, four times, eight times, or sixteen times the period P _A of the CSI-RS transmission subframe. 2 bits are required for information for indicating how many times of these, that is, information for indicating a bitmap information construction period. This 2-bit information can indicate whether or not the CSI-RS is actually a subframe for each CSI-RS transmission subframe within the bitmap information construction period P _B. The size of the bitmap may be 2 bits, 4 bits, 8 bits, or 16 bits, and each bit corresponds to one CSI-RS transmission subframe.

For another example, when i = 2, k = 3, the bitmap information construction period P _B is four times, eight times, sixteen times, or thirty-two times the period P _A of the CSI-RS transmission subframe. 2 bits are required for information for indicating how many times of these, that is, information for indicating a bitmap information construction period. This 2-bit information can indicate whether or not the CSI-RS is actually a subframe for each CSI-RS transmission subframe within the bitmap information construction period P _B. The size of the bitmap may be 4 bits, 8 bits, 16 bits, or 32 bits, and each bit corresponds to one CSI-RS transmission subframe.

For another example, when i = 1, k = 7, the bitmap information construction period P _B is 2 times, 4 times, 8 times, 16 times the period P _A of the CSI-RS transmission subframe. It can be 32 times, 64 times, 128 times, or 256 times, and three bits are required for information indicating how many times of these, that is, information indicating a bitmap information construction period. The 3-bit information can indicate whether or not the CSI-RS is actually a subframe for each CSI-RS transmission subframe within the bitmap information construction period P _B. The bitmap may be 2 bits, 4 bits, 8 bits, 16 bits, 32 bits, 64 bits, 128 bits, or 256 bits, and each bit corresponds to one CSI-RS transmission subframe.

Referring back to FIG. 3, the terminal 10 receives a bitmap through higher layer signaling, and then, among the CSI-RS transmission subframes, the subframe and the CSI-RS are actually transmitted among the CSI-RS transmission subframes. The subframe that is not transmitted is checked (S320).

The transmitter 20-A or 20-B may include a subframe for transmitting a special subframe, a PSS / SSS, a PBCH, and a SIB1 message among the configured CSI-RS transmission subframes, and a subframe for transmitting a paging message. Except for actually transmitting the CSI-RS in the subframe in which the CSI-RS is transmitted (S330), the UE 10 measures the channel by receiving the CSI-RS in the subframe in which the CSI-RS is actually transmitted (S330). S340).

5 is a flowchart illustrating a CSI-RS transmission subframe signaling method according to another embodiment of the present invention.

Referring to FIG. 5, the transmitting end 20-A to which the terminal 10 belongs transmits a parameter for configuring CSI-RS through higher layer signaling such as RRC (Radio Resource Control) (S510). The parameter for CSI-RS configuration may be set for each of one or more transmission terminals that may communicate with the terminal or may communicate with the terminal, and may be delivered to the terminal. That is, in the example of FIG. 2, the parameters for setting the CSI-RS are the parameters for setting the CSI-RS of the transmitting terminal 20-A to which the terminal belongs and the CSI-RS of the transmitting terminal 20-B to which the terminal does not belong. Contains parameters for configuration.

Also, the parameter for CSI-RS configuration is one subframe in which the CSI-RS is not transmitted by the CSI-RS due to a special subframe, PSS / SSS, PBCH, SIB1, paging message, etc. among the CSI-RS transmission subframes. It may include a bit value indicating.

The bit value may be a value indicating one subframe that does not actually transmit the CSI-RS among CSI-RS transmission subframes within a specific period P _B. The CSI-RS is not transmitted in the subframe designated as the bit value among the CSI-RS transmission subframes within the specific period P _B , and the CSI-RS is transmitted in the remaining subframes. When the period of the CSI-RS transmission subframe is P _A (for example, 5, 10, 20, 40, or 80 subframes), P _B / P _A CSI-RS transmissions within a specific period P _B There may be a subframe, and the bit value indicates a subframe in which the CSI-RS is not transmitted, and may have a value of 0 to P _B / P _A -1, and the number of bits for the bit value is

Can be.

In the example of FIG. 6, the period P _A of the CSI-RS transmission subframe is 40 ms (40 subframes) based on the information (subframeConfig) (I _CSI-RS in Table 1) for the CSI-RS transmission subframe. Is determined. On the other hand, the specific period (P _B ) is assumed to be 320 ms (320 subframes) as a value that is transmitted to higher layer signaling or preset. In this case, the bit value may have a value of 000 to 111.

In the example of FIG. 6, a CSI-RS transmission subframe belonging to a sixth CSI-RS transmission subframe period (CSI-RS transmission period index # 5) out of eight CSI-RS transmission subframe periods is a special subframe, PSS / In the case of a subframe in which the CSI-RS is not actually transmitted by the SSS, the PBCH, the SIB1, the paging message, or the like, the bit value may be '101' (5).

The specific period P _B may be one of 320 ms (320 subframes), 640 ms (640 subframes), 1280 ms (1280 subframes), or 2560 ms (2560 subframes) equal to the transmission period of the paging message. have. Considering all the subframes for transmission of the special subframe, PSS / SSS, PBCH, and SIB1, these subframes may correspond to subframe indexes # 0 and # 5, which are 5 ms (5 subframe) periods ( Or, in the case of TDD, it may correspond to subframe indexes # 1 and # 6). Since the period P _A of the CSI-RS transmission subframe is a multiple of 5 ms (5 subframes), the CSI-RS transmission subframe includes a subframe for transmission of a special subframe, PSS / SSS, PBCH, or SIB1. It always matches or does not always match. That is, when the CSI-RS transmission subframe is configured with subframe indexes # 0 or # 5 (when configured with # 1 or # 6 in the case of TDD), CSI-RS transmission may not be possible every time. In order to prevent such a case, the transmitter will configure the subframes for transmitting the CSI-RS transmission subframe and the special subframe, PSS / SSS, PBCH, and SIB1 to be different from each other. Therefore, it may be possible to consider only subframes in which CSI-RS cannot be actually transmitted by paging message transmission among CSI-RS transmission subframes, and a specific period P _B may be set equal to the transmission period of a paging message. have.

In a first example, the specific period P _B is a predefined value 320 ms (320 subframes), 640 ms (640 subframes), 1280 ms (1280 subframes), or 2560 ms (2560 subframes). It may be one of, but is not limited thereto. When the period P _A of the CSI-RS transmission subframe is determined based on the information (subframeConfig) for the CSI-RS transmission subframe, the range of the bit value is 0 to P _B / P _A −1, and the bit value The number of bits of

Will be. In this example, the range and number of bits of the bit value may be changed according to the period P _A of the CSI-RS transmission subframe.

For example, the specific period P _B is preset in 320 ms (320 subframes), and the period P _A of the CSI-RS transmission subframe is set in the information (subframeConfig) for the CSI-RS transmission subframe. When it is determined based on 40 subframes, the bit value has a range of '000' to '111' and can be represented by 3 bits.

In a second example, the specific period P _B is indicated via higher layer signaling and is 320 ms (320 subframes), 640 ms (640 subframes), 1280 ms (1280 subframes), or 2560 ms (2560 subframes). ), But is not limited thereto. The transmitting end may transmit a value indicating a specific period P _B through higher layer signaling. That is, the transmitting end transmits a value indicating a specific period P _B and a value indicating a subframe in which the CSI-RS is not transmitted within the specific period P _B through higher layer signaling. When the period P _A of the CSI-RS transmission subframe is determined based on the information (subframeConfig) for the CSI-RS transmission subframe, the range of the bit value is 0 to P _B / P _A −1, and the bit value The number of bits of

Will be. In this example, the range and number of bits of the bit value may be changed according to the value indicating the specific period P _B and the period P _A of the CSI-RS transmission subframe.

For example, which of 320, 640, 1280, or 2560 subframes is designated as a specific period P _B may be indicated by a 2-bit value through higher layer signaling. For (P _B g., 2-bit value is '00' of the case 320 sub-frame, "01" in case of 640 sub-frames, in the case of "10" of 1280 sub-frame, and when the "11" every particular with 2560 sub-frame ) Can be set. The specific period P _B is determined to be 320 subframes by the 2-bit value, and the period PA of the CSI-RS transmission subframes is determined to 40 subframes by the information (subframeConfig) for the CSI-RS transmission subframe. At this time, the bit value indicating the subframe in which the CSI-RS is not transmitted may be configured with 3 bits.

In a third example, the specific period P _B may be determined as a multiple of the CSI-RS transmission subframe period P _A. The specific period P _B may be an exponent (2 ⁱ ) times 2 of the CSI-RS transmission subframe period P _A , where the multiple is a value previously promised as one value or indicated by one of several Can be.

For example, the specific period P _B may be fixed to 32 times the CSI-RS transmission subframe period P _A. In this case, the bit value indicating the subframe in which the CSI-RS is not transmitted has a range of '00000' to '11111', and the number of bits for indicating the bit value will be 5 bits.

As another example, the specific period P _B may be indicated as one of 32 times, 64 times, 128 times, and 256 times the CSI-RS transmission subframe period P _A. In this case, a value for indicating how many times the period P _B is the CSI-RS transmission subframe period P _A may be delivered through higher layer signaling. If the specific period P _B is one of 32 times, 64 times, 128 times, and 256 times the CSI-RS transmission subframe period P _A , the value for indicating how many times will be 2 bits. When it is determined how many times the specific period P _B is the CSI-RS transmission subframe period P _A , the bit value indicating the subframe in which the CSI-RS is not transmitted is determined.

Will have the number of bits.

On the other hand, there may be a case where there is no subframe that does not actually transmit the CSI-RS within a specific period (P _B ) (that is, CSI-RS is transmitted in all CSI-RS transmission subframes within a specific period (P _B )). May be the case). In this case, the bit value may be a specific value indicating that there is no subframe that does not actually transmit the CSI-RS. Alternatively, the bit value may not be set and may not be transmitted to the terminal 10.

Referring back to FIG. 5, the terminal 10 receives a bit value through higher layer signaling, and then a subframe in which the CSI-RS is actually transmitted and the CSI-RS are transmitted among the CSI-RS transmission subframes using the bit value. The subframe that is not transmitted is checked (S520).

The transmitter 20-A or 20-B may include a subframe for transmitting a special subframe, a PSS / SSS, a PBCH, and a SIB1 message among the configured CSI-RS transmission subframes, and a subframe for transmitting a paging message. Except for actually transmitting the CSI-RS in the subframe in which the CSI-RS is transmitted (530), the UE 10 measures the channel by receiving the CSI-RS in the subframe in which it is confirmed that the CSI-RS is actually transmitted ( S540).

7 is a block diagram showing the configuration of a transmission stage according to an embodiment of the present invention.

Referring to FIG. 7, the transmitter 700 generates a first parameter setting unit 710 and a parameter setting unit 710 for generating a first parameter for determining timing (period and offset) of a subframe in which the CSI-RS is to be transmitted. Setting a second parameter including information on a subframe in which the CSI-RS is actually transmitted (or a subframe in which the CSI-RS is not transmitted) among the subframes in which the CSI-RS is determined by the parameter set in FIG. A parameter transmitter 730 for transmitting a second parameter set by the second parameter setting unit 720, a first parameter set by the first parameter setting unit 710 and a second parameter set by the second parameter setting unit 720, and a CSI− CSI-RS transmitter 740 for transmitting the RS.

The first parameter setting unit 710 generates a first parameter that determines the period and offset of the subframe in which the CSI-RS is to be transmitted. The first parameter may be SubframeConfig of Table 1 and may be an 8-bit value of 0 to 154.

The second parameter setting unit 720 determines a subframe in which the CSI-RS is actually transmitted (or a subframe in which the CSI-RS is not transmitted) among the subframes in which the CSI-RS is transmitted. The CSI-RS may not be transmitted in a special subframe (in case of TDD) among the subframes in which the CSI-RS is to be transmitted and in a subframe in which the PSS / SSS / PBCH / SIB1 / paging message is transmitted.

The second parameter setting unit 720 may include a second parameter including information on a subframe in which the CSI-RS is actually transmitted (or a subframe in which the CSI-RS is not transmitted) among the subframes in which the CSI-RS is transmitted. Create

In one example, the second parameter may be a bitmap. Whether or not the CSI-RS is transmitted in each CSI-RS transmission subframe may be represented by one bit in the bitmap.

The information construction period P _B of the bitmap may be a predefined fixed value. The size (bit number) of the bitmap may be determined according to the period P _A of the CSI-RS transmission subframe.

Alternatively, the size (number of bits) of the bitmap may be a predefined fixed value. The information configuration period P _B of the bitmap may be determined according to the period P _A of the CSI-RS transmission subframe.

Alternatively, the size (number of bits) of the bitmap may be a value selected from among a plurality of values. In this case, the second parameter may further include information indicating the size of the bitmap in addition to the bitmap. The information configuration period P _B of the bitmap may be determined according to the information indicating the size of the bitmap and the period P _A of the CSI-RS transmission subframe.

In another example, the second parameter can be a bit value. When the CSI-RS is not transmitted in one of the CSI-RS transmission subframes within a specific period P _B , the bit value may be a value indicating one subframe in which the CSI-RS is not transmitted.

The specific period P _B may be a predefined fixed value. The range of bit values may be determined according to the period P _A of the CSI-RS transmission subframe.

Alternatively, the specific period P _B may be a value selected from a plurality of values. In this case, the second parameter may further include information indicating a specific period P _B in addition to the bit value. The range of the bit value may be determined according to the information indicating the specific period P _B and the period P _A of the CSI-RS transmission subframe.

Alternatively, the range of the bit value (or a multiple indicating how many times the period P _A of the CSI-RS transmission subframe is a predetermined period P _B ) may be a predefined fixed value. The specific period P _B may be determined according to the period P _A of the CSI-RS transmission subframe.

Alternatively, the range of the bit value (or a multiple indicating how many times a particular period (P _B) the period (P _A of a CSI-RS subframe transmission)) may be a value selected from a plurality of values. In this case, the second parameter may further include information indicating a multiple in addition to the bit value. The specific period P _B may be determined according to the information indicating the multiple and the period P _A of the CSI-RS transmission subframe.

The parameter transmitter 730 transmits the first parameter set by the first parameter setter 710 and the second parameter set by the second parameter setter 720 to the terminal belonging to the transmitter 700 through higher layer signaling. . The parameter transmitted from the parameter transmitter 730 may include a first parameter and a second parameter set by the transmitter 700, as well as a first transmitter set by another transmitter capable of communicating with or communicating with a terminal belonging to the transmitter 700. Parameters and second parameters. Thus, in the CoMP environment, the terminal can receive the CSI-RS from a plurality of transmitters.

The CSI-RS transmitter 740 transmits the CSI-RS in a designated subframe based on the first parameter set by the first parameter setter 710 and the second parameter set by the second parameter setter 720.

8 is a block diagram illustrating a configuration of a terminal according to an embodiment of the present invention.

Referring to FIG. 8, the terminal 800 includes a parameter receiver 810, a subframe confirmation unit 820 for identifying a subframe in which the CSI-RS is to be transmitted, a CSI-RS receiver 830 for receiving the CSI-RS, And a channel measuring unit 840 performing channel measurement using the received CSI-RS.

The parameter receiver 810 receives a first parameter indicating a period and an offset of a CSI-RS transmission subframe through which the CSI-RS is transmitted through higher layer signaling. In addition, the parameter receiver 810 differs from a second parameter indicating a subframe in which the CSI-RS is actually transmitted (or a subframe in which the CSI-RS is not transmitted) among the CSI-RS transmission subframes indicated by a period and an offset. Receive via layer signaling. The set of the first parameter and the second parameter received by the parameter receiver 810 may be plural, depending on a transmitting end through which the terminal 800 may communicate.

The subframe checking unit 820 extracts the period and offset of the CSI-RS transmission subframe using the first parameter, and determines the CSI-RS transmission subframe using the period and the offset. The subframe identifying unit 820 identifies a subframe in which the CSI-RS is actually transmitted among the CSI-RS transmission subframes using the second parameter. When a plurality of sets of the first parameter and the second parameter are received by the parameter receiver 810, the subframe checking unit 820 confirms the subframe through which the CSI-RS is transmitted for each set.

The CSI-RS receiver 830 receives the CSI-RS transmitted by the transmitter. In this case, the transmitting end transmitting the CSI-RS may be a transmitting end to which the terminal 800 belongs or an adjacent transmitting end.

The channel measuring unit 840 performs channel measurement using the received CSI-RS.

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 under No. 119 (a) (35 USC § 119 (a)) of the Patent Application No. 10-2012-0050421 filed with Korea on May 11, 2012. All content is incorporated by reference in this patent application. In addition, if this patent application claims priority for the same reason for countries other than the United States, all its contents are incorporated into this patent application by reference.

Claims

In a system in which one terminal can communicate in cooperation with a plurality of transmission terminals, the transmission terminal,

Among the CSI-RS transmission subframes in which the CSI-RS transmission subframes, which are expressed as a period and an offset and are supposed to transmit a CSI-RS, are not actually transmitted, and / or the CSI-RS is actually transmitted. A parameter setting unit generating a parameter indicating subframes not to be generated; And

And a transmitter for transmitting the generated parameter to a terminal.
The method of claim 1,

The parameter is a transmission end, characterized in that consisting of a bitmap corresponding to one bit for each of the predetermined CSI-RS transmission subframes.
The method of claim 1,

And the parameter is configured with a bit value indicating a subframe in which the CSI-RS is not actually transmitted.
A terminal capable of communicating in cooperation with a plurality of transmission terminals,

Among the CSI-RS transmission subframes in which the CSI-RS transmission subframes, which are expressed as a period and an offset and are supposed to transmit a CSI-RS, are not actually transmitted, and / or the CSI-RS is actually transmitted. A parameter receiver configured to receive a parameter indicating subframes not to be used; And

And a subframe checking unit for checking subframes in which CSI-RS is actually transmitted using the received parameter.
The method of claim 4, wherein

The parameter is characterized in that the terminal is configured with a bitmap corresponding to one bit for each of the predetermined CSI-RS transmission subframes.
The method of claim 4, wherein

The parameter is characterized in that the terminal is configured with a bit value indicating a subframe that is not actually transmitted CSI-RS.
In a system in which one terminal communicates in cooperation with a plurality of transmission terminals, a method of signaling a CSI-RS transmission subframe by a transmission terminal,

Among the CSI-RS transmission subframes in which the CSI-RS is expected to be transmitted, expressed as a period and an offset, a parameter indicating subframes in which the CSI-RS is actually transmitted and / or subframes in which the CSI-RS is not actually transmitted. Generating; And

CSI-RS transmission subframe signaling method comprising the step of transmitting the parameter to the terminal.
The method of claim 7, wherein

The parameter is a CSI-RS transmission subframe signaling method comprising a bitmap corresponding to one bit for each of the predetermined CSI-RS transmission subframes.
The method of claim 7, wherein

The parameter is a CSI-RS transmission subframe signaling method, characterized in that consisting of a bit value indicating a subframe in which the CSI-RS is not actually transmitted.
In a system in which one terminal communicates in cooperation with a plurality of transmission terminals, a method in which a terminal checks a CSI-RS transmission subframe,

Among the CSI-RS transmission subframes in which the CSI-RS is expected to be transmitted, expressed as a period and an offset, a parameter indicating subframes in which the CSI-RS is actually transmitted and / or subframes in which the CSI-RS is not actually transmitted. Receiving; And

And identifying subframes in which the CSI-RS is actually transmitted using the parameter.
The method of claim 10,

And wherein the parameter comprises a bitmap corresponding to one bit for each of the predetermined CSI-RS transmission subframes.
The method of claim 10,

The parameter is a CSI-RS transmission subframe confirmation method, characterized in that consisting of a bit value indicating a subframe in which the CSI-RS is not actually transmitted.