KR20120093026A - Apparatus and method for allocating reference signal in communication system, and apparatus and method for receiving reference signal using the same - Google Patents

Abstract

PURPOSE: An apparatus and method for allocating a reference signal in a wireless communication system and an apparatus and method for receiving the reference signal using the same are provided to prevent the deterioration of terminal positioning and channel estimation performance by preventing the duplication of resources with a sub frame unit or an RE(Resource Element) unit. CONSTITUTION: PRS(Positioning Reference Signal) configuration information about one or more base stations or cells including oneself is identified(S1210). A CSI-RS(Channel State Information-Reference Signal) subframe is determined in order to maximally prevent from being overlapped with subframes formed for PRS transmission(S1220). A CSI-RS is allocated to only the n number of CSI-RS patterns from the N number of usable CSI-RS patterns when the CSI-RS subframe and the PRS transmission subframe are overlapped(S1230). A PRS is muted or punctured in order not to transmit the PRS to a corresponding RE(Resource Element)(S1240).

Description

Apparatus and Method for Allocating Reference Signal in communication system, and Apparatus and Method for Receiving Reference Signal using the same}

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a wireless communication system, and in particular, a positioning reference signal (hereinafter, referred to as a 'PRS' or a 'position reference signal') or a channel state information-reference signal in a wireless communication system. (Hereinafter, referred to as 'CSI-RS'), and a reference signal receiving apparatus and method using the same.

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

In the current mobile communication system, as a high-speed large-capacity communication system capable of transmitting and receiving various data such as video and wireless data beyond voice-oriented services, there is a demand for developing a technology capable of transmitting large-capacity data corresponding to a wired communication network. In addition, there is a need for an appropriate error detection method that can improve system performance by minimizing the reduction of information loss and increasing system transmission efficiency.

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

Among them, in order to measure the position of a user equipment (UE), each cell or base station transmits a Positioning Reference Signal (PRS) to the UE, and the corresponding UE transmits each of these signals at a specific time. The location reference signal from the base station is received and the location is measured.

To date, a communication system such as Long Term Evolution (LTE) employs a configuration of transmitting a location reference signal (PRS) in N subframes in succession with a specific period (T subframes).

In addition, in the next-generation communication technology such as LTE-A, which is currently being developed, uplink can support up to 8 antennas. Accordingly, in order to grasp channel information during downlink transmission, CRS defined only for the existing 4 antennas There is a limit to this, and for this purpose, CSI-RS (CSI-RS) is newly defined as a reference signal to identify channel state information of up to eight antennas.

In other words, a communication system using up to 8 × 8 multiple input multiple output antennas (MIMO) in both transmitting and receiving terminals has been discussed, and an antenna for receiving or transmitting a signal by a user equipment (UE) Different CSI-RSs must be transmitted for each port or antenna layer, and the user terminal receives the CSI-RS to estimate the channel state.

These PRSs and CSI-RSs are defined and used for different functions, but since they are allocated and transmitted in the time-frequency resource space of a subframe having a certain offset every specific period, two reference signals are allocated on the same resource space. In this case, since accurate reference signals are not available, there is a risk of deterioration of performance of position measurement (in case of PRS) or channel state estimation (in case of CSI-RS).

Accordingly, in the present invention, when the PRS and the CSI-RS are allocated and transmitted in the resource space, the PRS or the CSI-RS enables the two RSs not to overlap as much as possible, thereby improving the accuracy of the UE positioning or the performance of the channel estimation. We propose a transmission and reception technique.

An object of the present invention is to provide an apparatus and method for transmitting and receiving PRS or CSI-RS in a wireless communication system.

In addition, the present invention is to provide a technique for configuring a subframe to which two reference signals are transmitted in the allocation of PRS or CSI-RS in a wireless communication system so as not to overlap as much as possible.

In the present invention, in resource allocation of a PRS or CSI-RS in a wireless communication system, resource elements (hereinafter, referred to as' RE's) of a time-frequency resource space to which two reference signals are allocated are not duplicated as much as possible. It is intended to provide a technique that is configured to avoid.

In addition, the present invention is configured so that in the resource allocation of the PRS or CSI-RS in the wireless communication system, the subframes to which the two reference signals will be transmitted are not overlapped as much as possible, but the subframes to which the two reference signals are transmitted are duplicated. In this case, a technique for configuring a resource element (hereinafter, referred to as 'RE') in a time-frequency resource space to which two reference signals are allocated in a overlapping subframe is not duplicated as much as possible.

According to an embodiment of the present invention, in the wireless communication system, the second reference signal configuration information for one or more cells is allocated when the first reference signal, which is a reference target signal of PRS and CSI-RS, is allocated to the time-frequency resource space and transmitted. And identifying first reference signal configuration information such that the first reference signal transmission subframe is determined so as not to overlap with a subframe configured for transmission of the second reference signal. Provide a method.

According to another embodiment of the present invention, in the method of allocating PRS and CSI-RS, checking the PRS configuration information and the CSI-RS configuration information and confirming whether the PRS and CSI-RS are allocated to the same subframe. And allocating the CSI-RS only to the n CSI-RS patterns which are part of the available N CSI-RS patterns when the PRS and the CSI-RS should be allocated to the same subframe. To provide.

Another embodiment of the present invention is an apparatus for allocating a first reference signal, which is a reference target signal of PRS and CSI-RS, to a time-frequency resource space in a wireless communication system, and generating a first reference signal sequence. A generator, a second reference signal configuration information checking unit for identifying the second reference signal configuration information for one or more cells, and first reference signal configuration information for allocating the first reference signal sequence to a time-frequency resource region A reference signal allocation apparatus including a first reference signal resource allocator configured to determine first reference signal configuration information so as to determine the first reference signal configuration information so as not to overlap with the identified second reference signal configuration information in at least one unit of a subframe and an RE; to provide.

Another embodiment of the present invention is a method for receiving a reference signal in a wireless communication system, in which a terminal is generated by resource allocation so that duplication of a PRS sequence and a CSI-RS sequence is avoided as much as possible in units of at least one of a subframe and an RE from a base station. Receiving an OFDM signal, demodulating the received OFDM signal, extracting the PRS sequence and the CSI-RS sequence, and estimating location information and channel state information from the extracted PRS sequence and CSI-RS sequence It provides a reference signal receiving method comprising a.

Another embodiment of the present invention is an apparatus for receiving a reference signal in a wireless communication system,

A reception processor for receiving an OFDM signal generated by resource allocation from a cell or a base station such that a subframe unit or RE unit PRS sequence and a CSI-RS sequence are avoided as much as possible, and demodulating the OFDM signal to demodulate the PRS sequence and the CSI-RS sequence; A reference signal receiver includes a sequence extractor for extracting a sequence and a measurer for estimating position information and channel state information using the extracted PRS sequence and CSI-RS sequence.

1 is a diagram schematically illustrating a wireless communication system to which an embodiment of the present invention is applied.
2 illustrates a general subframe and time slot structure of transmission data that can be applied to an embodiment of the present invention.
3 illustrates a PRS signal pattern in a wireless communication system.
4 shows a signal transmission scheme of a PRS.
5 illustrates a CSI-RS signal pattern in a wireless communication system.
6 is a flowchart of a CSI-RS allocation method according to the first embodiment of the present invention.
FIG. 7 illustrates an example of a CSI-RS subframe configuration according to the CSI-RS resource allocation method of the embodiment of FIG. 6, in which FIG. 7A is in a synchronous reception state of a terminal, and FIG. 7B is in an asynchronous reception state of a terminal. Corresponding.
8 is a flowchart of a PRS allocation method in the first embodiment of the present invention.
FIG. 9 illustrates an example of a configuration of a PRS subframe using the PRS resource allocation method of the embodiment of FIG. 8, in which FIG. 9A corresponds to a first scheme and FIG. 9B corresponds to a second scheme.
10 is a flowchart of a reference signal allocation method according to a second embodiment of the present invention.
11 shows an example of a reference signal allocation pattern according to the second embodiment.
12 is a flowchart illustrating a reference signal allocation method according to an embodiment in which some of the first embodiment and the second embodiment are combined.
13 is a block diagram of an apparatus for allocating a reference signal according to an embodiment of the present invention.
14 is a functional block diagram of a reference signal transmission apparatus 1400 to which the present embodiments are applied.
15 is a flowchart illustrating a method for receiving a reference signal according to an embodiment of the present invention.
16 is a diagram showing the structure of a reference signal receiving apparatus according to the present embodiment.

Hereinafter, some embodiments of the present invention will be described in detail with reference to exemplary drawings. In adding reference numerals to the components of each drawing, it should be noted that the same reference numerals are assigned to the same components as much as possible even though they are shown in different drawings. In the following description of the present invention, a detailed description of known functions and configurations incorporated herein will be omitted when it may make the subject matter of the present invention rather unclear.

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

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

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

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

The base station 20 or cell generally refers to all devices or functions or specific areas that communicate with the terminal 10, and may include a Node-B, an evolved Node-B, and a sector. ), Site, Base Transceiver System (BTS), Access Point, Access Node, Relay Node, etc.

That is, in the present specification, the base station 20 or a cell is a part covered by a base station controller (BSC) in CDMA, a NodeB in WCDMA, an eNB (or a site) or a sector in LTE. It should be interpreted as a comprehensive meaning of an area or function, and encompasses various coverage areas such as megacell, macrocell, microcell, picocell, femtocell and relay node communication range.

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

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

The uplink transmission and the downlink transmission may use a time division duplex (TDD) scheme transmitted using different times, or use a frequency division duplex (FDD) scheme transmitted using different frequencies, or both. A hybrid division duplex (HDD) system, which is a complex form of the system, may be used.

The present invention should not be construed as being limited or limited to a specific wireless communication field, but should be construed as including all technical fields to which the spirit of the present invention can be applied.

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

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

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

The basic unit of data transmission is a subframe unit, and downlink or uplink scheduling is performed on a subframe basis. One slot may include a plurality of OFDM symbols in the region of the time axis and a plurality of subcarriers (or subcarriers) in the region of the frequency axis.

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

2 is a diagram illustrating various subframe and time slot structures of transmission data that may be applied to an embodiment of the present invention.

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

Referring to 2B of FIG. 2, the TTI is a basic transmission unit, and one TTI includes two time slots 202 of the same length, each time slot having a duration of 0.5 ms. Have The time-slot includes a plurality of long blocks (LB) 203 corresponding to each symbol. LBs are separated by cyclic prefix (CP) 204. At this time, the cyclic prefix includes a normal cyclic prefix (Normal CP) and an extended cyclic prefix (Extended CP) according to the length thereof. In the case of using a normal cyclic prefix (Normal CP), the plurality of LBs are included in a single time-slot, and in the case of using an extended cyclic prefix (Extended CP), the plurality of LBs are one Six or three are included in the time slot.

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

2C of FIG. 2 illustrates a configuration of one resource block (RB) 230 during one subframe or TTI 201 according to an embodiment of the present invention, wherein each TTI or subframe has a normal cyclic prefix in the time domain. In the case of (Normal CP), 14 symbols (axis) or an extended cyclic prefix (Extended CP) is divided into 12 (or 6) symbols (axis) 220. Each symbol (axis) may carry one OFDM symbol.

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

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

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

For example, in a resource region corresponding to a bandwidth of 180 kHZ in an area of the time axis and in an area of the frequency axis, when a normal cyclic prefix (Normal CP) is used and the frequency bandwidth per subcarrier is 15 kHz, A total of 14 (symbols) × 12 (subcarriers) = 168 REs may exist in each resource region of the above structure.

Meanwhile, as reference signals defined in downlink in the LTE communication system, cell-specific reference signals (CRSs) and MBSFN reference signals (Multicast / Broadcast over Single Frequency Network Reference Signals; MBSFN -RS and UE-specific reference signal, or DM-RS (Demodulation Reference Signal).

On the other hand, it is necessary to measure the location of the terminal to provide various location services in the wideband code division multiple access (WCDMA) and location information necessary for communication.

These positioning methods are largely 1) the cell coverage-based positioning method, 2) Observed Time Difference of Arrival (OTDOA) method, and 3) network-assisted GPS. It is based on three methods of assisted GPS methods. Each method is complementary rather than competitive, and is used appropriately for each different purpose.

Among these, the OTDOA method is based on measuring a location by measuring relative arrival times of RSs or pilots from different base stations or cells. In this case, the reference signal used at this time is a Positioning Reference Signal (PRS).

Since the location calculation uses triangulation, the UE must receive the reference signal RS from at least three different base stations or cells.

To facilitate OTDOA positioning and avoid near-far problems, the WCDMA standard uses IDL Periods in Downlink (IPDL) technology, during which the UE is located on the same frequency where the current UE is located. Even if a reference signal from a serving cell is strong, it should be able to receive a reference signal from a neighbor cell.

In addition, the LTE (Long Term Evolution) system developed from 3GPP series WCDMA is based on Orthogonal Frequency Division Multiplexing (OFDM), unlike the asynchronous CDMA (Code Division Multiple Access) method of WCDMA. Currently, in the WCDMA mentioned above, a new LTE system is considering a method for measuring position based on the OTDOA method, such as the positioning using the OTDOA method, and for this, the MBSFN subframe (Multicast Broadcast Single Frequency Network subframe) and the normal In each subframe structure of one or both of the subframes, a data region is emptied at regular intervals, and a reference signal for positioning, ie, PRS, is sent to the vacant region. This is under consideration.

In other words, for positioning in LTE, the new next-generation communication method based on OFDM, it is based on the OTDOA method in the existing WCDMA, but in the new resource allocation structure due to the change of the communication base such as the multiplexing method and the access method. It is necessary to reconsider the method of sending a reference signal for positioning and the configuration of the reference signal. Also, a more accurate positioning method is developed by the development of a communication system such as an increase in the UE's moving speed, a change in the interference environment between base stations, and an increase in complexity. It is required.

Accordingly, in the current LTE, a method in a Release 9 version has been determined regarding a method of configuring and transmitting and receiving a PRS in consideration of the above situation.

3 is a diagram illustrating a PRS pattern in a communication system considering only a macro cell.

The PRS pattern corresponds to a bandwidth of one subframe (corresponding to 1 ms) on the time axis and one resource block (RB) on the frequency axis, and typically has 12 subcarriers when the bandwidth per subcarrier is 15 kHz. Corresponding to).

As shown in FIG. 3, the PRS transmits the PRS by leaving a data region excluding a control region and a cell-specific reference signal (CRS) in a specific subframe, and includes a pattern for the PRS, That is, the RE to which the PRS sequence is assigned can be shifted six times on the frequency axis, thereby transmitting the location reference signals in different patterns for up to six base station (cell) groups. That is, all of the base stations (cells) transmit the PRS in one of a total of six patterns at a specific corresponding time, and the corresponding UE (UE) for each PRS measurement receives the PRS from each base station transmitted at this specific time. Receive and measure position.

The frequency shift is based on a physical cell ID (PCI), which is a base station (cell) number (ID), and there are only 6 possible patterns, but adjacent base stations (cells) are distributed through appropriate distribution of the base station (cell) number (ID). In order to reduce the interference between neighboring base stations (cells) by adjusting cell planning, ie, cell planning, so as not to use the same pattern as much as possible.

That is, the PRS pattern number may be defined as PCI mod 6.

FIG. 3 illustrates a case in which one or two PBCH antenna ports are used. In the case of four PBCH antenna ports, the PRS is not allocated to the second symbol axis (l = 1) of the odd slot in the illustrated resource space.

4 shows a method of transmitting a PRS.

As shown in FIG. 4, the PRS is transmitted in consecutive N subframes having specific periods (T subframes). In this case, the specific period may be one of 160ms, 320ms, 640ms, and 1280ms (1ms corresponds to one subframe. For example, if the period is 160ms, the PRS is transmitted every 160 subframes.) In this case, the information or the value of the specific period may be signaled at the upper end in the form of a combination with a specific offset value.

Therefore, if the specific period is T _PRS , the specific offset value is Δ _PRS , the value signaled at the upper end is I _PRS , and the consecutive N subframes are N _PRS , The location reference signal is transmitted in consecutive N _PRS subframes.

[Equation 1]

At this time, T _PRS is one of 160, 320, 640, 1280, △ _PRS has a value from 0 to T _{PRS -} 1. In addition, I _PRS expressed as a total of 12 bits (has a value from 0 to 4095) is T _PRS = 160 from 0 to 159, and offset value △ _{PRS at} that time, T _PRS = 320 days from 160 to 479. represents the time and the time offset value △ _PRS, 480 ~ 1119 by T _PRS = 640 il time and the time offset value △ _PRS, T _PRS = 1280 il time and the offset value △ _PRS of time until 1120-2399 . N _PRS is also a value transmitted from the upper end and is one of 1, 2, 4 and 6. In addition, n _f is a system frame number, n _s is a slot number.

For example, if N _PRS = 4 and I _PRS = 200 signaled from the upper end, since period T _PRS = 160 and offset △ _PRS = 40, 4 consecutive subframes every 160 subframes with 40 subframes as offsets. PRS is transmitted in the subframes.

At this time, not all base stations (cells) transmit PRS, but specific base stations (cells) transmit location reference signals in subframes configured to transmit PRS, but some other base stations (cells) do not transmit PRS. They may perform muting or blanking that transmits at zero power without transmitting PRS in subframes configured by a specific base station (cell) to transmit a location reference. This is one of methods for reducing the influence of the interference in consideration of the case where a large number of neighboring base stations (cells) having the same PRS pattern exist.

Muting may be performed for each transmission period (T _PRS ) of the _PRS . N _PRS subs configured to transmit a location reference within each period by viewing each transmission period (T _PRS ) as one bit and using 2, 4, 8, or 16 periods as bitmap information. For the frames, it is decided whether to actually transmit or mute the PRS. This bitmap information is configured for each base station (cell) and transmitted by an upper end.

For example, when the bitmap information is composed of four bits of bitmap information for four periods and its bit value is '1001' (when 1 is referred to as position reference signal and 0 is muting); Of course, on the contrary, bitmap information may be configured by transmitting a location reference signal with 0, muting 1), and N _PRS subframes configured to transmit location references within the first and fourth PRS transmission periods. For _PRS subframes, the N _PRS subframes configured to transmit location references within the second and third PRS transmission periods do not transmit PRS but transmit with zero power. muting).

In summary, the 'PRS (transmission) subframe' in which the PRS is transmitted may be configured by an upper layer through I _PRS , which is an index or a parameter. I _PRS denotes a cell-specific subframe configuration period T _PRS (= 160, 320, 640, 1280 ms) and Δ _PRS (= 0 to T _PRS -1) which is a subframe offset.

There are six PRS patterns (REs for PRS transmission, that is, information on time / frequency resource location) in one subframe, and are defined by PCI (Physical Cell ID). Specifically, the PRS pattern number is PCI mod 6 may be.

3 shows a possible PRS pattern in the case of a normal CP and an extended CP, and shows one of six patterns. The remaining patterns shift the shown pattern along the frequency axis.

For reference, PRS may be transmitted to antenna port number 6, 0 to 3 is CRS, 4 is MBSFN-RS, 5 is Rel-8 UE-specific RS (DM-RS), 6 is PRS, and 7 to 14 Rel-9 / 10 DM-RS, 15-22 may be used for CSI-RS, but is not limited thereto.

Meanwhile, the CSI-RS signal, which is a reference signal or a reference signal, is described as follows to identify channel information during downlink transmission.

The CRS, which is a cell-specific reference signal, may be included in all downlink subframes of a cell supporting physical downlink shared channel (PDSCH) transmission and transmitted. It may also be transmitted in one or multiple of antenna port numbers 0-3.

In addition, one reference signal is transmitted for each downlink antenna port, and an RE used for CRS transmission of one of the antenna ports in the slot cannot be used for another antenna port in the same slot.

When CRSs are mapped to REs of different time-frequency domains for each of four antenna ports, REs to which CRSs for each antenna port are allocated have a period of 6 for subcarriers, which are expressed as six frequency shift values. , The six frequency shift values V _shift Can be configured as PCI mod 6.

On the other hand, as described above, in some next-generation communication technology, up to eight antennas are supported in the downlink, and thus, in order to grasp channel information during downlink transmission, there is a limit to the CRS defined only for the existing four antennas. For this purpose, a reference signal called CSI-RS (hereinafter referred to as 'CSI-RS') may be newly defined to identify channel state information of up to eight antennas.

The CSI-RS, which is currently under discussion, includes 12 subcarriers corresponding to one resource block (RB) on a frequency axis for each cycle in a time cycle for each cell. As many as one RE (Resource Element) per antenna port in the region of.

That is, up to eight REs are allocated and transmitted for a total of eight antenna ports. In this case, T _{CSI - RS} corresponding to the predetermined period corresponds to a multiple of 5 ms of time consisting of five subframes. Specifically, TCSI-RS may be 5, 10, 20, 40, 80 ms, or the like. May be, but is not limited to.

If the duty cycle is 5ms, the CSI-RS is transmitted in a total of two subframes out of 10 subframes in one radio frame corresponding to 10ms. Therefore, if only the CSI-RS pattern for one subframe is defined, the other subframe needs to be allocated with a certain cycle.

In this specification, a duty cycle for transmitting the CSI-RS is defined as T _{CSI- RS} .

Meanwhile, a communication system using up to 8 × 8 multiple input multiple output antennas (MIMO) has been discussed in both transmitting and receiving terminals. Since a different CSI-RS must be transmitted for each antenna port or antenna layer, a transmitter is used. Needs to allocate CSI-RS for a total of eight antenna ports to be distinguished in the time-frequency domain, and in particular, it is necessary to allocate CSI-RS to distinguish between cells in a multi-cell environment.

In the present specification, the antenna layer refers to a data layer that can be logically simultaneously transmitted to multiple antenna ports in a base station or a mobile communication terminal. However, data of each antenna layer may be the same or different. Therefore, the number of antenna layers may be equal to or smaller than the number of antenna ports. On the other hand, the antenna port number is used to represent each time-frequency resource region. Therefore, when the antenna port number is different in the antenna port used for the same purpose, it means a time-frequency resource region that is spatially distinguished as different antennas.

For example, the antenna port numbers for CRSs using up to four antennas range from 0 to 3, with MBSFN-RS, LTE Rel-8 UE-specific RS (DM-RS), and Positioning (PRS) using up to one antenna each. Reference Signal) is 4, 5 and 6 antenna port numbers, respectively. In addition, the antenna port number of LTE Rel-10 DM-RS using up to 8 antennas is 7 to 14. In the case of CSI-RS, up to eight antennas are used, and subsequent antenna port numbers can be used. Antenna port numbers 15 to 22 are examples, so antenna port number 15 may be the first antenna port for CSI-RS transmission. In this case, when the antenna port number is different in each specific RS, it means that the antennas have time-resource regions that are spatially separated from each other.

Hereinafter, although described with reference to the antenna port, it may be applied to the antenna layer unit or the physical antenna reference.

A subframe in which the CSI-RS is transmitted may be referred to as a "CSI-RS subframe" or a "CSI-RS subframe", and the CSI-RS subframe is an upper layer through an index or a parameter I _{CSI - RS} . It can be configured by. I _{CSI - RS} is a cell-specific subframe configuration period T _{CSI -} represents an _{- (RS -1 = 0 ~ T} CSI) RS (= 5, 10, 20, 40, 80ms) and a subframe offset of Δ _{CSI- RS.}

The CS-RS pattern in which the CSI-RS is mapped to one subframe includes a normal structure of a subframe structure (hereinafter referred to as FS) and a cyclic shift (CP). It may be defined according to extended and the number of antenna ports (one of two, four, and eight).

Information on the CSI-RS pattern (REs for CSI-RS transmission, that is, information on time / frequency resource location) in one subframe is transmitted by an upper end, and the CSI-RS pattern is specifically a normal CP. In case of using (normal CP), 8 (= mandatory 5 and 3 optional) patterns when 8 CSI-RS transmit antennas are 8, and 16 (= mandatory 10 and 6 optional) 4 32 patterns (= mandatory 20 and optional 12) when there are 1 pattern or 2 patterns, and each cell is signaled at the upper end with 5 bits in consideration of a maximum of 32 patterns.

In the case of using Extended CP, when the number of CSI-RS transmit antennas is 8, 7 (= mandatory 4 and optional 3) patterns are used, and when 12, 12 (= mandatory 8 and When there are 6) optional patterns, 1 or 2 patterns, there are 28 patterns (= mandatory 16 and 12 optional) .In consideration of a total of 28 patterns, 5 bits are signaled at the upper end for each cell. .

Above, the mandatory case of the CSI-RS pattern number representation means a general case applied to both FS1 (FDD) and FS2 (TDD), and the optional case is only FS2 (TDD). Means additional cases that apply.

5 is defined as mandatory for both FS1 (FDD) and FS2 (TDD) and illustrates a possible CSI-RS pattern when having a normal CP and an extended CP, respectively.

That is, FIG. 5A illustrates all five CSI-RS patterns possible when the number of antenna ports is eight as a case of a mandatory having a normal CP, and FIG. 5B shows four CSIs available in the case of having an extended CP. -Show all the patterns of RS.

In FIG. 5 and below, numbers are numbers of respective antenna ports or antenna layers for CSI-RS transmission, and alphabet subscripts are identifiers indicating CSI-RS patterns.

As shown in FIG. 5A, when the antenna port has a normal CP and there are eight antenna ports (antenna port numbers 0 to 7), the antenna may have a total of five CSI-RS patterns up to a patterns to e patterns. have.

Although not shown, the CSI-RS patterns in the case of two or four CSI-RS antenna ports instead of eight are configured in a nested structure when the number of CSI-RS antenna ports is eight.

That is, the pattern when the number of CSI-RS antenna ports is four is composed of patterns divided within each specific pattern when the number of CSI-RS antenna ports is eight, so the total number of patterns is CSI-RS antenna This is doubled when the number of ports is eight. The pattern when the number of CSI-RS antenna ports is two is also composed of the divided patterns within each specific pattern when the number of CSI-RS antenna ports is four, so the total number of patterns is the number of CSI-RS antenna ports. It is twice as many as four.

For example, there are five CSI-RS patterns applied to the normal CP case in one subframe when the number of CSI-RS antenna ports is eight (a to e in FIG. 5), and the CSI-RS antenna When the number of ports is 4, the number is 10 (a to j), which is twice that, and when the number of CSI-RS antenna ports is 2, the number is 20 (a to t).

Meanwhile, FIG. 5B illustrates a case in which FS1 (Frame Structure 1, FDD) and FS2 (Frame Structure 2, TDD (except DwPTS of Special Subframe)) are applied in the same manner and are extended CP. do.

In the case of the extended CP as shown in FIG. 5B, a cell-specific reference signal (CRS), a control region, and a demodulation reference signal (DM-RS), which are previously used, are used among the total 12 symbols used for downlink. CSI-RSs can be allocated to the Rel-9 / 10 so that they do not overlap with the location of the Rel-9 / 10 region, and the antenna port has 8 extended antenna ports (antenna port numbers 0 to 7). ), It may have a total of four CSI-RS patterns from a pattern to d pattern.

Although not shown, the CSI-RS pattern when the number of CSI-RS antenna ports is two instead of eight is four, and the CSI-RS pattern has a nested structure when the number of CSI-RS antenna ports is eight. Same as above.

On the other hand, the CSI-RS pattern in the case of the additional (option) for FS2 (Frame Structure 2, TDD (except DwPTS of the special subframe)) is not shown separately, but in the case of normal CP, three CSI if the number of antennas is 8 -6 RS-RS patterns, 6 CSI-RS patterns if the number of antennas, 12 CSI-RS patterns are possible if the number of antennas is two.

In the case of an extended CP, three CSI-RS patterns are possible when the number of antennas is eight, six CSI-RS patterns when the number of antennas is four, and twelve CSI-RS patterns when the number of antennas is two.

 The characteristics of the PRS and CSI-RS as described above are summarized as follows.

[Table 1] Comparison of PRS and CSI-RS

On the other hand, configured by the higher layer (Configured by high layer) means that the base station (eNB or cell) is configured to transmit the reference signal to the UE through the cell-specific configuration information (cell-specific). In addition, the configuration information may be transmitted to each UE in the corresponding cell through RRC information and the like and used for demodulation. At this time, the subject constituting the specialized information for each cell may be an E-SMLC which is an upper end component in the case of PRS, and the CSI-RS may be a base station (eNB or cell), but is not limited thereto.

As described above, in 3GPP LTE, which is one of the OFDM-based systems, a Positioning Reference Signal (PRS), which is one of downlink reference signals defined in the LTE Rel-9 system, is used to determine the position of a user equipment (UE) by OTDOA (Position). Observed Time Difference of Arrival). Meanwhile, a channel-state information reference signal (CSI-RS) defined in the LTE Rel-10 system is used for channel measurement, followed by a cell-specific reference signal (CRS) defined in the LTE Rel-8 system. .

The PRS and the CSI-RS are transmitted in a specific transmission subframe with cell-specific periods and subframe offsets, respectively, and are subframes configured for transmission of respective reference signals. In a subframes configured for PRS or CSI-RS transmission, each cell is transmitted to a specific resource resource (RE) with a cell-specific pattern.

In this case, the transmission subframe defined for each reference signal (PRS or CSI-RS) may have a different value for each cell, and if there are no special constraints, the two reference signals are substantially the same in the same subframe. PRS and CSI-RS can be transmitted simultaneously.

In addition, when the two reference signals are transmitted in the same subframe, the patterns defined for each cell for each reference signal also overlap substantially, which may cause a collision problem.

When PRS and CSI-RS collide with each other, the following situation may occur and cause performance degradation on the system.

First, since the period of the transmission subframe that can be allocated for the PRS is a multiple of the period of the transmission subframe that can be allocated for the CSI-RS, the PRS of every subsequent period when the PRS and the CSI-RS collide in one subframe Each transmission subframe collides with the CSI-RS transmission subframe. This affects the accuracy of the Observed Time Difference of Arrival (OTDOA) measurement (OTDOA measurement accuracy) required for measuring the position of the user equipment (UE). Here, in the case of the Rel-9 UE performing positioning measurement, REs for all PRS transmissions in the collided subframe are used for positioning without information on the CSI-RS configuration. The REs collide with the CSI-RS to include REs in which information for the CSI-RS is mixed as well as the PRS. Therefore, the accuracy of the OTDOA measurement may be affected, causing performance degradation in UE location measurement.

In addition, in the case of Rel-10 UE performing positioning measurement, only the REs that do not collide with the CSI-RS among the REs for PRS transmission with information on the CSI-RS configuration may be used for the position measurement. I will try. However, even in this case, performance degradation may be caused by the reduction of REs for PRS transmission used for position measurement.

On the other hand, in the case of the Rel-10 UE which does not perform the position measurement but performs the CSI-RS measurement, the UE measures the CSI-RS without information on the PRS configuration. That is, the REs for CSI-RS transmission collide with the PRS to include REs in which information for the PRS is mixed as well as the CSI-RS. Therefore, this affects the CSI measurement accuracy.

Therefore, a need arises for allocating and transmitting each reference signal to avoid collision between two downlink reference signals, PRS and CSI-RS, in an OFDM based system.

Hereinafter, the allocation target reference signal among the PRS and the CSI-RS will be expressed as a first reference signal and a second reference signal that is the remaining reference signals.

Accordingly, according to an embodiment of the present invention, when the first reference signal, which is a reference target signal of PRS and CSI-RS, is allocated to the time-frequency resource space and transmitted, the second reference signal configuration information for one or more cells is checked. And determining configuration information (transmission subframe or allocation resource element) of the first reference signal so as not to overlap with a subframe or resource element configured for transmission of the second reference signal. It suggests an allocation method.

Of course, the method may further include allocating and transmitting the first reference signal to the determined subframe or the allocated resource element.

If the E-SMLC schedules the PRS, the aforementioned first reference signal is a PRS, the second reference signal is a CSI-RS, and a base station (eNB or cell) allocates and transmits the CSI-RS. The first reference signal will be a CSI-RS and the second reference signal will be a PRS.

As a specific method of allocating transmission subframes or REs of the PRS and the CSI-RS to the time-frequency resource space so as not to overlap as much as possible, the first embodiment avoids duplication in subframe units and avoids duplication in RE units. It can be roughly divided into the second embodiment.

According to the first embodiment, the step of identifying the second reference signal configuration information for one or more cells in the allocation of the first reference signal, which is a target reference signal of the PRS and CSI-RS in the time-frequency resource space, The method may include determining a transmission subframe of the first reference signal such that it does not overlap with a subframe configured for the transmission of the second reference signal.

In addition, the first embodiment is a method of limiting CSI-RS allocation in consideration of the given PRS configuration information (FIGS. 6 and 7), and in contrast, a method of controlling PRS allocation in consideration of the given CSI-RS configuration information (FIG. 8). , 9).

In addition, in the method of controlling PRS allocation in consideration of CSI-RS configuration information (FIGS. 8 and 9) in the first embodiment, the first method of configuring a PRS subframe again by completely avoiding the CSI-RS subframe (FIG. 9). A) and a second method of constructing a PRS subframe by avoiding CSI-RS subframes as much as possible, but performing PRS muting on the overlapping subframes (b of FIG. 9).

Meanwhile, according to the second embodiment, when the PRS and the CSI-RS are allocated to the same subframe, allocating the CSI-RS only to the n CSI-RS patterns which are part of the available N CSI-RS patterns, and the CSI If there is an RE to which the PRS should be allocated in the CSI-RS pattern to which the RS is allocated, the RE includes assigning the PRS and the CSI-RS by muting or puncturing not to transmit the PRS. It is configured by. In this case, when the number of antennas is 8, normal CP, and mandatory for both FDD / TDD, three CSI-RS patterns arranged on the 10th and 11th symbol axes among the total 5 CSI-RS patterns available. It is preferable to assign the CSI-RS only. (I.e., N = 5, n = 3)

In this case, a total of four REs among the 24 REs included in the three CSI-RS patterns are REs to which the original PRSs are assigned. In the second embodiment, PRSs are not allocated to the four REs, that is, muting. Or puncturing.

 Hereinafter, specific configurations of the first and second embodiments will be further described with reference to the drawings.

6 to 9 are views for the first embodiment, and Figs. 10 to 11 are for the second embodiment.

6 is a flowchart of a CSI-RS allocation method according to the first embodiment of the present invention.

According to an embodiment of the present invention, in order to allocate the CSI-RS, which is an allocation target reference signal among the PRS and the CSI-RS, to the time-frequency resource space, identifying PRS configuration information about one or more base stations or cells including itself. Step S610 and determining the CSI-RS configuration information so as not to overlap with the subframe configured for the PRS transmission (S620).

Here, the CSI-RS allocation method as shown in FIG. 6 may be performed in a base station or a cell, but is not limited thereto, and should be interpreted as including all components for scheduling CSI-RS transmission.

In addition, prior to S610 may include a step (S605) of receiving the PRS configuration information from one or more base stations (cells) or higher stages including the self, and the SRS confirms the transferred PRS configuration information. .

In addition, the method may further include allocating the CSI-RS to a specific RE of a specific subframe and transmitting the same to the UE according to the CSI-RS configuration information determined after S620 (S630).

When determining a CSI-RS subframe in step S620, subtract the number of consecutive PRS transmission subframes (N _PRS ) of a cell or a base station considered in its CSI-RS transmission period (T _{CSI -RS} ) (T _CSI-RS -N _PRS ) CSI-RS subframes can be selected among the server frames, but this is an ideal case.

That is, when the UE actually receives the PRS from several base stations or cells, it may be in an Asynchronous Receiving State due to the difference in time delay, so that when the UE determines its CSI-RS subframe, (T _{CSI - RS-} (N _PRS +1 or 2) after subtracting 1 or 2 from the number of consecutive PRS transmission subframes (N _PRS ) of the cell or base station considered in the RS transmission period (T _{CSI - RS} ) A CSI-RS subframe may be selected from among)) server frames. Or, considering the worst case from the above case, it could be easily unified to ' T _{CSI - RS-} ( N _PRS +2)'.

Here, if the N _PRSs of the cell or base station under consideration are different from each other, the largest value among the N _PRSs of the cell or base station under consideration is selected as the N _PRS applied to the scheme.

This will be described in more detail with reference to FIG. 7 below.

Referring to the embodiment of Figure 6 as described above in more detail as follows.

6: Method of Limiting CSI-RS Subframe Configuration Using Given PRS Configuration Information

In the embodiment of FIG. 6, the CSI-RS transmission subframe is configured to avoid a subframe for preconfigured PRS transmission.

More specifically, each base station (eNB) or cell,

a) receiving information about the PRS transmission subframe configuration (at this time, for the PRS transmission subframe configuration from the cell belonging to at least the corresponding base station (eNB), as well as all neighboring cells transmitting the PRS if necessary; Information (ex. I _PRS (PRS transmission period ( T _PRS ), transmission subframe offset (△ _PRS )), N _PRS (Number of consecutive transmission subframes within one period), etc.)

b) construct a CSI-RS transmission subframe by avoiding a subframe for PRS transmission based on the received PRS transmission subframe configuration information;

c) a corresponding reference signal is allocated to a subframe for the configured PRS transmission and a subframe for the CSI-RS transmission configured by the process of b).

The number of sub-frames (offset) to avoid the PRS in the _RS assigns a CSI-RS is received in the synchronous state 'T _{CSI-RS - -} Here, the b) given CSI-RS transmission period T _CSI in N _PRS , or ' T _{CSI - RS} ( N _PRS +2)' or ' T _{CSI - RS-} ( N _PRS +1)' in the asynchronous reception state. Or, considering the worst case from the above case, it could be easily unified to ' T _{CSI -RS-} ( N _PRS +2)'.

That is, when the terminal receives the PRS from a plurality of base stations or cells, an ideal case of receiving the PRS of all the cells in a synchronized state without delay is 'synchronous reception state', and a case where some delay occurs is 'asynchronous reception state'. Assume that

FIG. 7 illustrates an example of a CSI-RS subframe configuration according to the CSI-RS resource allocation method of the embodiment of FIG. 6, in which FIG. 7A is in a synchronous reception state of a terminal, and FIG. 7B is in an asynchronous reception state of a terminal. Corresponding.

FIG. 7 illustrates a subframe configuration in which a specific UE receives PRS from seven cells or base stations.

In FIG. 7, one grid means one subframe and shows a total of ten subframes horizontally, and a serving cell (that is, a cell to which the CSI-RS allocation method according to the present embodiment is applied) and six neighboring cells or It is exemplified by considering the PRS configuration of the base station. That is, it is assumed that the UE receives the PRS in the sixth and seventh subframes from each of seven cells from the top to the bottom.

In this case, a in FIG. 7 is a synchronous reception state. In this case, in determining the CSI-RS subframe, at least one of 1 to 5, 8 to 10 server frames except for the 6 and 7 subframes in which the PRS is transmitted. May be selected as the CSI-RS transmission subframe. That is, CSI-RS transmission period T _{CSI - RS -} the number of sub-frames (offset) to avoid a PRS within (Fig. 7, T _{CSI RS} assuming ereul 10ms) assigning a CSI-RS is' T _{CSI - RS} - N _PRS = (10-2) = 8 '.

Meanwhile, as shown in b of FIG. 7, when the terminal receives the PRS from the multiple cells, some delay occurs, resulting in the asynchronous reception state in which the PRS is asynchronously received, and thus, the actual multiple cells transmit the PRS. The 5th and / or 8th subframes, which are immediately preceding and / or immediately following the 6th, 7th subframe, may also be excluded from the CSI-RS subframe. That is, in FIG. 7B, the CSI-RS transmission period T _{CSI - RS} ( T _{CSI - RS in} Figure 7 In this example, the number of subframes (offsets) that can be allocated to the CSI-RS by avoiding the PRS within the range is' T _{CSI - RS-} ( N _PRS +1 or 2) = (10- (1 or 2)) = 7 or 6 '.

8 is a flowchart of a PRS allocation method in the first embodiment of the present invention.

According to the embodiment of FIG. 8, in order to allocate a PRS, which is an allocation target reference signal among PRSs and CSI-RSs, to the time-frequency resource space, identifying CSI-RS configuration information of one or more base stations or cells (S810). And determining (S820) the PRS (transmission) configuration information so as not to overlap with a subframe or resource element configured for transmission of the CSI-RS as much as possible.

Here, the PRS transmission configuration information includes at least one of PRS (transmission) subframe information for PRS transmission and PRS allocation RE which is a time-frequency resource space to which the PRS is allocated.

In step S810, the base station or cell in which the CSI-RS configuration information is confirmed may be a specific number of neighboring base stations or cells including itself.

In addition, the PRS allocation method as shown in FIG. 8 may be performed by an upper component, such as an E-SMLC, but is not limited thereto, and should be interpreted as including all components for scheduling PRS of each base station or cell.

In addition, the method may further include a step (S805) of receiving the CSI-RS configuration information from one or more base stations or cells before S810, and in S810, the CSI-RS configuration information is thus confirmed.

The method may further include transmitting the PRS configuration information determined after S820 to a corresponding base station or cell (S830), wherein the base station or cell that has received the PRS configuration information may specify a specific subframe according to the PRS configuration information. PRS is allocated to the RE and can be transmitted to the UE.

Here, the CSI-RS configuration information may include CSI-RS transmission period ( T _{CSI - RS} ) and transmission subframe offset (△ _{CSI - RS} ) information, which will be signaled in the form of I _{CSI - RS} as described above. Could be.

When determining the PRS (transmission) configuration information such that the subframe configured for transmission of the CSI-RS is not duplicated as much as possible, 1) the subframe to which the CSI-RS is transmitted and the PRS transmission subframe do not overlap at all; 1 and 2) a second method of determining that the subframe through which the CSI-RS is transmitted and the PRS transmission subframe do not overlap as much as possible, but muting the PRS for the redundant subframe.

Referring to the embodiment of Figure 8 in more detail as follows.

8: Method of Limiting PRS Subframe Configuration Using Given CSI-RS Configuration Information

In the embodiment of FIG. 8, the PRS transmission subframe is configured to avoid a subframe for preconfigured CSI-RS transmission, and may be further divided into a first scheme and a second scheme.

More specifically, the E-SMLC (upper end scheduling each base station eNB for positioning),

a) receiving information on CSI-RS transmission subframe configuration (i.e., CSI-RS configuration information) from each eNB or cell (ex. I _{CSI - RS)} (CSI-RS transmission period ( T _{CSI - RS} ), transmission subframe offset (△ _CSI-RS ), etc.)

b) construct a PRS transmission subframe of each cell by avoiding a subframe for CSI-RS transmission based on the CSI-RS transmission subframe configuration information of each base station or cell received;

c) E-SMLC transmits the determined PRS transmission subframe configuration information to the corresponding cell or base station

The base station or cell receiving the PRS configuration information from the E-SMLC allocates the PRS and CSI-RS to the terminal based on the preconfigured CSI-RS configuration information and the PRS configuration information received by the process of c).

Then, the terminal decodes the PRS and the CSI-RS to perform positioning and channel state estimation. According to the embodiment, since the time-frequency region to which the PRS and the CSI-RS are allocated does not overlap as much as possible, accurate positioning and channel estimation is performed. This becomes possible.

Meanwhile, in the first method, the PRS transmission subframe is not completely overlapped with the CSI-RS subframe, but in the second method, the PRS may be muted when there are some overlapping subframes.

That is, in the second scheme, the E-SMLC (upper stage scheduling each base station eNB for positioning) is:

a) receiving information on CSI-RS transmission subframe configuration (i.e., CSI-RS configuration information) from each base station (eNB) or a cell (ex. I _{CSI - RS);} (CSI-RS transmission period ( T _{CSI - RS} ), transmission subframe offset (CSI-RS)), etc.)

b) PRS transmission subframe of each cell is constructed by avoiding subframes for CSI-RS transmission as much as possible based on the CSI-RS transmission subframe configuration information of each base station or cell received (duplicate subframes may be generated) However, by generating PRS muting information for muting the PRS for the duplicate subframe,

c) The E-SMLC transmits PRS transmission subframe configuration information including PRS muting information to a corresponding cell or base station.

The base station or cell receiving the PRS configuration information from the E-SMLC allocates the PRS and the CSI-RS based on the preconfigured CSI-RS configuration information and the PRS configuration information (including PRS muting information) received by the process of c). To transmit to the terminal.

FIG. 9 illustrates an example of a configuration of a PRS subframe using the PRS resource allocation method of the embodiment of FIG. 8, in which FIG. 9A corresponds to a first scheme and FIG. 9B corresponds to a second scheme.

In FIG. 9, one lattice means one subframe, and a total of 13 subframes are shown horizontally. Considering the CSI-RS configuration of a total of seven neighboring cells or base stations (including their own base station / cell), To illustrate. That is, it is assumed that each of seven cells from top to bottom has a CSI-RS transmission period of 10, 5, 20, 5, 10, 10, and 10 ms, and transmits CSI-RS in a shaded subframe.

As in FIG. 9A, when the E-SMLC determines PRS configuration information of a specific cell or base station, the CSI-RS server frame of another identified cell / base station is completely excluded. That is, in FIG. 9A, the PRS configuration information is determined such that only one or more of the subframes (fourth, fifth, ninth, and tenth subframes) in which seven other cells / base stations do not transmit the CSI-RS at all. It is decided.

In the second scheme as shown in FIG. 9B, the PRS subframe is selected so as not to overlap with the CSI-RS subframe as much as possible, but the PRS is muted for the subframe overlapping with the CSI-RS subframe of some other cell / base station.

That is, in FIG. 9B, at least one of the 4th to 10th subframes is determined as the PRS transmission subframe so as not to overlap with the CSI-RS subframe as much as possible. Information will be determined.

Hereinafter, a second embodiment of avoiding collision in RE units will be described.

10 is a flowchart of a reference signal allocation method according to a second embodiment of the present invention.

In the method for allocating a PRS and a CSI-RS, the method for allocating a reference signal according to the second embodiment of the present invention includes: checking the PRS configuration information and the CSI-RS configuration information (S1010), in the same subframe. Confirming whether the PRS and the CSI-RS are allocated (S1020), when the PRS and the CSI-RS are allocated to the same subframe, only the CSI-RS patterns of the n CSI-RS patterns which are part of the N CSI-RS patterns available It may be configured to include a step (S1030).

In addition, if there is an RE to which the PRS should be allocated in the CSI-RS pattern to which the CSI-RS is allocated, the RE may further include muting or puncturing so as not to transmit the PRS (S1040). Can be.

In the second embodiment, a total of five CSI-RS patterns usable when the number of antennas (ports) to transmit the CSI-RS is 8, normal CP, and mandatory for both FS1 (FDD) and FS2 (TDD) It is preferable to assign the CSI-RS only to a total of three CSI-RS patterns arranged on the 10th and 11th symbol axes. (I.e., N = 5, n = 3)

In this case, a total of four REs among the 24 REs included in the three CSI-RS patterns are REs to which the original PRSs are assigned. In the second embodiment, PRSs are not allocated to the four REs, that is, muting. Or puncturing.

In addition, when the number of antennas (ports) to transmit CSI-RS is 4, normal CP, and mandatory for both FS1 (FDD) and FS2 (TDD), the 10th and 11th of the total 10 CSI-RS patterns available It is preferable to assign the CSI-RS only to a total of six CSI-RS patterns arranged on the symbol axis. (Ie N = 10, n = 6)

In addition, if the number of antennas (ports) to transmit CSI-RS is 2, normal CP, and mandatory for both FS1 (FDD) and FS2 (TDD), the 10th and 11th of the total 20 CSI-RS patterns available It is preferable to assign the CSI-RS only to a total of 12 CSI-RS patterns arranged on the symbol axis. (That is, N = 20, n = 12)

If the number of antennas (ports) to transmit CSI-RS is 8/4/2, extended CP and mandatory for both FS1 (FDD) and FS2 (TDD), the total of 4/8/16 CSI available In the -RS pattern, it is preferable to assign the CSI-RS only to a total of 2/4/8 CSI-RS patterns arranged on the fifth and sixth symbol axes or the eleventh and twelfth symbol axes. (I.e. when the number of antennas (ports) is 8, 4 and 2 respectively, N is 4, 8 and 16 respectively and n is 2, 4 and 8 respectively)

This second embodiment may be implemented alone or in combination with the first embodiment described above in some cases.

That is, although the second embodiment alone has the effect of avoiding collision between the PRS and the CSI-RS, even if according to the first embodiment, a subframe having the same PRS and the CSI-RS must be allocated. May be implemented in series with the first embodiment.

For example, in a method of limiting CSI-RS allocation in consideration of PRS configuration information given as shown in FIGS. 6 and 7 in the first embodiment, if a CSI-RS transmission period ( T _{CSI - RS} 6), a duplicate avoidance scheme as shown in FIGS. 6 and 7 may not be sufficient if the value is small and the number of consecutive transmission subframes N _{PRS of the PRS} is large. (I.e. the CSI-RS allocation limit is greater) Even, for example, T _{CSI - RS} In the special case of = 5 ms and N _PRS = 6, the above-described embodiments of FIGS. 6 and 7 are not applicable. The second embodiment can be configured in such a case.

FIG. 11 shows an example of a reference signal allocation pattern according to the second embodiment, and corresponds to a case where the number of antennas (ports) is eight, normal CPs, and mandatory for both FDD / TDD.

If the number of antennas (ports) is 8, normal CP, and mandatory for both FDD / TDD, as shown in FIG. 5, a total of 5 CSI-RS patterns are available (patterns a to e).

In the second embodiment, the CSI-RS is allocated to only some of the CSI-RS patterns.

In the second embodiment, some patterns for allocating the CSI-RS may be determined in the order of the smallest number of collisions with the RE for the PRS allocation in the pattern, but is not limited thereto.

As shown in FIG. 11, the CSI-RS is allocated to only three CSI-RS patterns having 0 or 1 REs for PRS allocation, that is, three CSI-RS patterns in the 10th and 11th symbol axes, among the total 5 patterns. .

In addition, as shown in FIG. 11, if there is an RE to which the PRS should be allocated in the CSI-RS pattern to which the CSI-RS is allocated, the RE is muted or punctured so as not to transmit the PRS. .

According to this second embodiment, some REs may not transmit PRS in the pattern for PRS transmission, but the ratio is not large. For example, in the resource space consisting of a total of one subframe (1ms) and 12 subcarriers (180Khz) in FIG. 11, as a result, a total of 14 REs are allocated for PRS transmission, but some REs (0 4) are not muted or punctured to transmit PRS, but instead transmit CSI-RS.

As shown in FIG. 11, according to the second embodiment, among the five CSI-RS patterns that can be allocated in the case where the number of antennas (ports) is eight, normal CP, and mandatory for both FDD / TDD, Only 3 patterns (for example, CSI-RS pattern can be assigned to a pattern, b pattern, and c pattern) can be assigned.In this case, when sending CSI-RS as a pattern, there are 2 REs overlapping with PRS and b pattern. When sending CSI-RS, there are 0 overlapping REs and when sending CSI-RS in c pattern, there are 2 overlapping REs. In a multi-cell environment such as CoMP or HeNet, CSI-RS is considered in consideration of multiple cells at the same time. Even when sending, only up to four REs (CSI-RS pattern a + b + c) overlap the PRS.

12 is a flowchart illustrating a reference signal allocation method according to an embodiment in which some of the first embodiment and the second embodiment are combined.

According to the embodiment of Figure 12, in order to allocate the PRS and CSI-RS in the time-frequency resource space, confirming the PRS configuration information for one or more base stations or cells including itself (S1210) and the PRS transmission Determining the CSI-RS subframe such that the CSI-RS subframe is overlapped with the PRS transmission subframe (S1220) so that the CSI-RS subframe is not overlapped with the subframe configured for the maximum number of available CSI-RS subframes. And allocating the CSI-RS to only n CSI-RS patterns which are some of the RS patterns (S1230).

In addition, when there is an RE to which the PRS should be allocated in the CSI-RS pattern to which the CSI-RS is allocated in step S1230, muting or puncturing the PRS so as not to transmit the PRS in the corresponding RE (S1240). It may further include.

In addition, as in the embodiment of FIG. 6, the method may further include a step (S1205) of receiving the PRS configuration information from one or more base stations (cells) or higher stages including itself before S1210. Check the PRS configuration information.

The method may further include allocating the CSI-RS and the PRS to a specific RE of a specific subframe according to the CSI-RS configuration information and the PRS configuration information determined after the S1230 or S1240 and transmitting the same to the UE.

In order to determine the CSI-RS subframe in step S1220, a given CSI-RS transmission period T _{CSI - RS} The number of subframes (offsets) that can be allocated to the CSI-RS to avoid the PRS within the ' T _{CSI - RS-} N _PRS , or ' T _CSI-RS- ( N _PRS +2)' or ' T _{CSI - RS-} ( N _PRS +1)', etc. in the asynchronous reception state. can be unified with _{'T CSI - - RS (N} PRS +2)' is the same as that of the first embodiment.

In addition, in steps S1230 and S1240, if the number of antennas (ports) to transmit the CSI-RS is 8, normal CP, and mandatory for both FS1 (FDD) and FS2 (TDD), the total of 5 CSI-RSs available. It is preferable to assign the CSI-RS only to a total of three CSI-RS patterns arranged on the 10th and 11th symbol axes among the RS patterns. (I.e., N = 5, n = 3)

In this case, a total of four REs among the 24 REs included in the three CSI-RS patterns are REs to which the original PRSs are allocated. In step S1240, the PRSs are not allocated to the four REs, that is, muting or popping. It is punching.

The detailed configuration of the embodiment according to FIG. 12 is summarized as follows.

Each base station (eNB) or cell,

a) receiving information on PRS transmission subframe configuration (at least information on PRS transmission subframe configuration from all neighboring cells transmitting PRS from a cell belonging to a corresponding base station (eNB) if necessary (ex. I _PRS (PRS transmission period ( T _PRS ), transmission subframe offset (△ _PRS )), N _PRS (Number of consecutive transmission subframes within one period), etc.)

b) Construct CSI-RS transmission subframe by avoiding subframe for PRS transmission as much as possible based on the received PRS transmission subframe configuration information

c) If the CSI-RS subframe and the PRS subframe overlap in step b) (whether duplication can be recognized through a) or b), within the subframe, PRS and CSI-RS transmission Assignable REs so that they do not overlap each other (i.e., assign CSI-RS to only some of the available CSI-RS patterns, and optionally mute or puncture to prevent PRS from being transmitted on all REs within CSI-RS allocation patterns) )

d) Allocating the corresponding reference signals (PRS and CSI-RS) to the UE to the subframe for the pre-configured PRS transmission and the CSI-RS transmission and the C configured by the process of b and c transmitted to the terminal

In addition, the embodiment as shown in FIG. 12 may include a configuration of signaling to the UE information of a PRS RE muted or punctured for transmission of the CSI-RS. Because of this, the UE must decode. Otherwise, if the muted or punctured PRS RE for the transmission of the CSI-RS is known as the RE for the PRS transmission and decoded, the information actually included is This is because there is a risk of deterioration of positioning performance since it is CSI-RS.

13 is a block diagram of an apparatus for allocating a reference signal according to an embodiment of the present invention.

Referring to FIG. 13, a reference signal resource allocation apparatus 1300 according to an embodiment of the present invention may include a reference signal sequence generator 1320, a second reference signal configuration information checking unit 1310, and a first reference signal resource allocator ( 1330). The first reference signal is a target reference signal for resource allocation in the time-frequency space among the PRS and the CSI-RS, and the second reference signal is the remaining reference signal.

In addition, the second reference signal configuration information receiver 1340 for receiving configuration information (one or more of a transmission period, an offset, the number of consecutive transmission subframes, and an allocation pattern) of the second reference signal from one or more adjacent cells / base stations or higher stages. ) May be further included.

The reference signal sequence generator 1320 receives external information such as system-specific information and generates a cell-specific PRS sequence or a CSI-RS sequence based thereon. In this case, the system-specific information may be one or more of base station information (cell ID, etc.), relay (relay) node information, terminal (user device) information, subframe number, slot number, OFDM symbol number, CP sizes, but is not limited thereto. It is not. The base station (cell) information may be, for example, base station antenna information, base station bandwidth degree, and base station cell ID information.

For example, the reference signal sequence generator 1310 may generate a PRS sequence or a CSI-RS sequence of each corresponding cell by receiving information such as a cell ID, a slot number, an OFDM symbol number, and a CP size.

The second reference signal configuration information confirming unit 1310 may function alone or in conjunction with the second reference signal configuration information receiving unit 1340, and may be configured to limit the allocation of the first reference signal. The second reference signal configuration information is checked.

The first reference signal resource allocator 1330 determines first reference signal configuration information for allocating the first reference signal sequence generated by the first reference signal sequence generator 1310 to the time-frequency resource region. The first reference signal configuration information is determined so as not to overlap with the transmission subframe and / or the RE of the second reference signal already confirmed.

That is, in the first reference signal resource allocator 1330, the PRS and the CSI-RS overlap each other as much as possible in the transmission subframe unit or the RE unit according to each embodiment described in connection with FIGS. 6 to 12 or a combination thereof. PRS configuration information or CSI-RS configuration information is determined so as not to.

That is, the first reference signal resource allocator 1330 is a first embodiment for avoiding duplication in units of subframes. The CSI-RS allocation is limited in consideration of given PRS configuration information (FIGS. 6 and 7; In contrast to the second reference signal, the CSI-RS is the first reference signal, a method of controlling PRS allocation in consideration of the given CSI-RS configuration information (FIGS. 8 and 9; PRS is the first reference signal and CSI-RS is the first reference signal). 2 reference signals) may be used. In a method of controlling PRS allocation in consideration of CSI-RS configuration information (FIGS. 8 and 9) in the first embodiment, a first method of configuring a PRS subframe by completely avoiding the CSI-RS subframe again (a in FIG. 9). ) And a second method (b of FIG. 9) for configuring a PRS subframe to avoid CSI-RS subframes as much as possible but performing PRS muting on the overlapping subframes.

In addition, when the first reference signal resource allocator 1330 allocates the PRS and the CSI-RS to the same subframe in order to avoid duplication in the RE unit, the n CSI-RS which is part of the available N CSI-RS patterns The CSI-RS can be assigned only to the pattern. In addition, if there is an RE to which the PRS should be allocated in the CSI-RS pattern to which the CSI-RS is assigned, muting or puncturing so that the PRS is not transmitted to the RE. can do.

For a more specific method of determining the first reference signal configuration information, description thereof is omitted in order to avoid overlapping with the description of FIGS. 6 to 12.

The first reference signal sequence assigned to the resource elements is then multiplexed with the base station transmission frame.

The first reference signal resource allocator 1330 is a resource allocation method for the PRS or the CSI-RS. The first reference signal resource allocator 1330 allocates resources to corresponding OFDM symbols and subcarrier (or subcarrier) positions according to a predetermined rule, and determines a predetermined frame timing. Performs a basic function of multiplexing with a base station transmission frame.

In addition, when the first reference signal is a PRS, the RS allocates each base station (eNB) inside or outside the E-SMLC, which is a component responsible for positioning at the upper end, or under the control of the E-SMLC. Alternatively, it may be implemented in the cell or in conjunction with it. When the first reference signal is CSI-RS, it may be implemented in the eNB or the cell or in conjunction with it.

Also, the first reference signal resource allocator 1330 may operate in conjunction with a resource element mapper which is a component of the base station apparatus. In some cases, the first reference signal resource allocator 1330 and the resource may be operated. The element mapper may be integrated to implement.

The entire base station apparatus or the reference signal transmission apparatus including the CSI-RS and / or the PRS will be described in more detail with reference to FIG. 14 below.

14 is a functional block diagram of a reference signal transmission apparatus 1400 to which the present embodiments are applied.

Referring to FIG. 14, the reference signal transmission apparatus 1400 according to the present embodiment includes a resource element mapper 1410, a reference signal assignment apparatus 1300 according to the present embodiment, and an OFDM signal processor ( 1430, and the like, and the reference signal allocating apparatus 1300 may be configured as shown in FIG. 13.

On the other hand, as shown by the dotted line, the reference signal transmission device 1400 may further include the configuration for the transmission of other data or information in addition to the CSI-RS, specifically, the configuration of the basic transmission device in the base station Elements such as a scrambler, a modulation mapper, a layer mapper, a layer mapper, a precoder, an OFDM signal generator, and the like may be further included, but in the present embodiment, such a configuration is included. This is not necessary.

On the other hand, the reference signal transmission device 1400 may be implemented in the communication system of the base station 10 of FIG. 1 or may be implemented in conjunction with it.

Referring to the basic operation of the reference signal transmission device 1400, bits input in the form of code words through channel coding in downlink are scrambled by a scrambler and then input to a modulation mapper. do. The modulation mapper modulates the scrambled bits into a complex modulation symbol, and the layer mapper maps the complex modulation symbol to one or more transport layers. The precoder then precodes the complex modulation symbol on each transmission channel of the antenna port. The resource element mapper then maps the complex modulation symbol for each antenna port to the corresponding resource element.

Meanwhile, according to the present embodiment, when the first reference signal sequence generator 1320 generates a reference signal sequence and transmits the reference signal sequence to the first reference signal resource allocator 1330, the first reference signal resource allocator 1330 may Alternatively, the CSI-RS or the PRS is allocated to the time-frequency domain according to the same method as described with reference to FIGS. 6 to 12 in conjunction with the resource element mapper, and multiplexed with the base station transmission frame at a predetermined frame timing.

In this case, the reference signal RS and the control signals including the PRS and / or the CSI-RS may be allocated to the resource elements first, and data received from the precoder may be allocated to the remaining resource elements, but is not limited thereto.

Thereafter, the OFDM signal processor 1430 generates a complex time domain OFDM signal for the time-frequency resource region to which the first reference signal sequence is allocated so that duplication with the second reference signal is avoided in units of subframes and REs. The complex time domain OFDM signal is transmitted through the corresponding antenna port.

According to an embodiment of the present invention, the RS 1300 and the resource element mapper 1410 may be implemented in hardware or software.

In particular, the first reference signal resource allocator 1330 of the reference signal allocation apparatus 1300 may be implemented to be integrated with the resource element mapper 1410 of the transmitting apparatus. In this case, the first reference signal resource allocator 1330 may be implemented. Or a resource element mapper 1410.

Although the signal generation structure of the downlink physical channel of the wireless communication system to which the embodiments are applied is described above with reference to FIG. 14, the present invention is not limited thereto. That is, the signal generation structure of the downlink physical channel of the wireless communication system to which the embodiments of the present invention are applied may omit other components, substitute or change other components, or add other components.

15 is a flowchart illustrating a method for receiving a reference signal according to an embodiment of the present invention.

The method of receiving a reference signal according to an embodiment of the present invention is generally performed by a terminal, but is not limited thereto.

In the method of receiving a reference signal according to the embodiment of FIG. 15, the UE receives an OFDM signal generated by resource allocation so that duplication of a PRS sequence and a CSI-RS sequence is avoided as much as possible in one or more units of a subframe and an RE from a base station ( S1510, demodulating the received OFDM signal to extract the PRS sequence and the CSI-RS sequence (S1520), and estimating the location information and the channel state information from the extracted PRS sequence and the CSI-RS sequence ( S1530) may be configured to include.

The OFDM signal received by the UE in step S1510 is generated by resource allocation such that duplication of PRS sequence and CSI-RS sequence is avoided as much as possible, and the scheme of FIG. 6 to FIG. Can be used.

That is, in order to avoid duplication on a subframe basis (one embodiment), a method of limiting CSI-RS allocation in consideration of given PRS configuration information (FIGS. 6 and 7; PRS is the second reference signal and CSI-RS is the first method). In contrast, a method of controlling PRS allocation in consideration of given CSI-RS configuration information (FIGS. 8 and 9; PRS is the first reference signal and CSI-RS is the second reference signal) may be used. When the PRS and the CSI-RS are allocated to the same subframe in order to avoid duplication in the RE unit (second embodiment), the CSI-RS is allocated only to the n CSI-RS patterns which are part of the available N CSI-RS patterns. Alternatively, if there is an RE to which the PRS should be allocated in the CSI-RS pattern to which the CSI-RS is allocated, a method of muting or puncturing such that the PRS is not transmitted may be used. The detailed description will be omitted in order to avoid duplication of explanation. .

The PRS sequence or CSI-RS sequence extraction in step S1520 is performed in conjunction with or included in a resource element de-mapping for extracting specific information (data or control signal, etc.) from the demodulated OFDM signal. Can be. That is, in the resource element demapping process after OFDM signal demodulation, only REs for PRS and CSI-RS are selected among all REs that are the targets of resource element demapping (this is the PRS pattern and the CSI-RS pattern). Corresponding to the PRS sequence and the CSI-RS sequence mapped to the REs.

Estimating the position information in step S1530 extracts the PRS sequence of each cell from the OFDM signal transmitted from each cell (preferably three or more pico cells or macro cells), and then auto-correlates the extracted PRS sequence. By measuring the peak by correlation, the delay time of the OFDM signal transmitted from each cell may be measured, and the location information of the terminal may be estimated by triangulation. .

16 is a diagram showing the structure of a reference signal receiving apparatus according to the present embodiment.

Referring to FIG. 16, a reference signal receiver 1600 of a terminal in a wireless communication system includes a reception processor 1610, a resource element de-mapper 1620, a reference signal sequence extractor 1630, and a measurement unit ( 1640) and the like, and although not shown, may further include a decoder, a controller, and the like. In this case, the receiver 1600 may be the terminal 10 of FIG. 1.

 The reception processor 1610 is resource-assigned to avoid duplication of OFDM signals generated by the RS 1300 according to the present embodiment, i.e., a subframe unit or RE unit PRS sequence and a CSI-RS sequence as much as possible. A function of receiving the generated OFDM signal from the cell or base station.

The resource element demapper 1620 demaps information allocated to respective resource elements in the received OFDM signal. The demapped information may include various reference signals such as cell-specific PRS or CSI-RS, in addition to control information and data information.

The sequence extractor 1630 may be a device included in or interlocked with the resource element demapper 1620, and in particular, the resource element demapper 1620 demaps information allocated to respective resource elements. Demaps the information related to the PRS and the CSI-RS to extract the PRS sequence and the CSI-RS sequence. Accordingly, the sequence extractor 1630 extracts the PRS sequence and the CSI-RS sequence in the reverse order of the reference signal allocation scheme according to one of the schemes described with reference to FIG. 14.

In addition, the measurement unit 1640 may estimate the location information of the corresponding UE from the PRS sequence for one or more cells (preferably three or more) extracted by the sequence extractor, and use the extracted CSI-RS sequence. It performs a function of estimating downlink channel state information.

In addition, the resource element demapper 1620 and the reference signal sequence extractor 1630 of the reference signal receiver 1600 according to the present embodiment are integrated and implemented to obtain information allocated to each resource element of the received OFDM signal. After demapping, a function of extracting a PRS sequence and a CSI-RS sequence of a cell transmitting the corresponding OFDM signal may be performed. In the present specification, these components will be collectively referred to as a reference signal sequence extractor 1630. .

The reference signal receiver 1600 is a device for receiving a signal transmitted from the reference signal transmitter 1400 in pairs with the wireless communication system or the reference signal transmitter 1400 described with reference to FIG. 14. Therefore, the reference signal receiving apparatus 1600 is composed of elements for signal processing of the reverse process of the reference signal transmitting apparatus 1400. Accordingly, it is to be understood that parts not specifically described with reference to the reference signal receiver 1600 may be replaced one-to-one with elements for signal processing in a reverse process of the reference signal transmitter 1400.

Using the above embodiments, in allocating and transmitting the reference signal PRS for positioning and the CSI-RS for channel estimation together in the resource space, by allocating and transmitting resources so as not to overlap as much as possible in subframe units or RE units, It is possible to prevent degradation of the positioning performance and the channel estimation performance of the terminal to the maximum.

Therefore, while simultaneously transmitting the PRS and CSI-RS, it is possible to accurately estimate the position of the terminal and estimate the channel state.

The foregoing description is merely illustrative of the technical idea of the present invention, and various changes and modifications may be made by those skilled in the art without departing from the essential characteristics of the present invention. Therefore, the embodiments disclosed in the present invention are intended to illustrate rather than limit the scope of 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.

Claims (15)

In the radio communication system, in the allocation of the first reference signal, which is a reference signal among PRS and CSI-RS, to be allocated to the time-frequency resource space,
Identifying second reference signal configuration information for one or more cells;
Determining first reference signal configuration information such that the first reference signal transmission subframe is determined such that the second reference signal is not overlapped with the subframe configured for transmission of the second reference signal;
Reference signal allocation method comprising a. The method of claim 1,
And receiving the second reference signal configuration information from at least one other base station or cell or higher level. The method of claim 1,
The first reference signal is a CSI-RS, the second reference signal is a PRS, and when determining a CSI-RS subframe for transmitting the CSI-RS, the PRS within a CSI-RS transmission period (T _{CSI - RS} ). (T _{CSI - RS} minus the number of subframes (N _PRS ) A reference signal allocation method, characterized in that CSI-RS subframes are selected from N _PRS ) server frames. The method of claim 1,
The first reference signal is a CSI-RS, the second reference signal is a PRS, and when determining a CSI-RS subframe for transmitting the CSI-RS, the PRS within a CSI-RS transmission period (T _{CSI - RS} ). Reference signal characterized in that the CSI-RS subframes are selected from among (T _{CSI - RS-} (N _PRS +1 or 2)) server frames minus one or two greater than the number of subframes (N _PRS ) Assignment method. The method of claim 1,
When the first reference signal is a PRS and the second reference signal is a CSI-RS, the CSI-RS is transmitted when the PRS subframe is determined so as not to overlap with a subframe configured for the transmission of the CSI-RS. And determining the PRS subframe such that the subframe and the PRS subframe do not overlap at all. The method according to claim 1,
The first reference signal is a PRS, the second reference signal is a CSI-RS, and the PRS subframe and the CSI- are determined as a result of determining the PRS subframe so as not to overlap with the subframe configured for the transmission of the CSI-RS. If the RS subframe partially overlaps, the reference signal allocation method, characterized in that muting the PRS in the overlapping subframe. The method of claim 1,
The first reference signal is a CSI-RS and the second reference signal is a PRS. As a result of determining the CSI-RS subframe for the CSI-RS transmission so as not to overlap with the PRS subframe for the PRS transmission, the PRS sub If the frame and the CSI-RS subframe partially overlap, further comprising allocating the CSI-RS only to the n CSI-RS patterns that are part of the N CSI-RS patterns available within the duplicated subframe. Reference signal allocation method characterized in that. The method of claim 7, wherein
And muting or puncturing the PSI to not transmit the PRS in the n CSI-RS patterns to which the CSI-RS is to be allocated. The method of claim 7, wherein
Total available when the number of antennas (ports) to transmit CSI-RS is M (M = 1,2,4,8), normal CP and mandatory for both FDD / TDD

Of 10 CSI-RS patterns in the 10th and 11th symbol axes

A reference signal allocation method, characterized in that CSI-RSs are assigned to only CSI-RS patterns. In the method of allocating PRS and CSI-RS,
Confirming the PRS configuration information and the CSI-RS configuration information;
Checking whether the PRS and the CSI-RS are allocated to the same subframe;
Allocating the CSI-RS only to the n CSI-RS patterns which are part of the N CSI-RS patterns available when the PRS and the CSI-RS are allocated to the same subframe;
Reference signal allocation method comprising a. The method of claim 10,
And muting or puncturing the PSI to not transmit the PRS in the n CSI-RS patterns to which the CSI-RS is to be allocated. The method of claim 10,
Total available when the number of antennas (ports) to transmit CSI-RS is M (M = 1,2,4,8), normal CP and mandatory for both FDD / TDD

Of 10 CSI-RS patterns in the 10th and 11th symbol axes

A reference signal allocation method, characterized in that CSI-RSs are assigned to only CSI-RS patterns. An apparatus for allocating a first reference signal, which is a reference target signal of PRS and CSI-RS, to a time-frequency resource space in a wireless communication system,
A reference signal sequence generator for generating the first reference signal sequence;
A second reference signal configuration information confirming unit for confirming the second reference signal configuration information for one or more cells;
Determine first reference signal configuration information for allocating the first reference signal sequence to a time-frequency resource region, so as not to overlap with the identified second reference signal configuration information in at least one unit of a subframe and an RE; A first reference signal resource allocator for determining one reference signal configuration information;
Reference signal allocation apparatus comprising a. A reference signal receiving method in a wireless communication system,
The terminal,
Receiving, from a base station, an OFDM signal generated by resource allocation such that a PRS sequence and a CSI-RS sequence are avoided as much as possible in units of at least one of a subframe and an RE;
Demodulating the received OFDM signal to extract the PRS sequence and the CSI-RS sequence;
Estimating location information and channel state information from the extracted PRS sequence and CSI-RS sequence;
Reference signal receiving method comprising a. Apparatus for receiving a reference signal in a wireless communication system,
A reception processor for receiving an OFDM signal generated by resource allocation so that a duplication of a subframe unit or RE unit PRS sequence and a CSI-RS sequence is avoided as much as possible;
A sequence extractor configured to demodulate the OFDM signal and extract the PRS sequence and the CSI-RS sequence;
A measurement unit estimating location information and channel state information using the extracted PRS sequence and CSI-RS sequence;
Reference signal receiving apparatus comprising a.

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