KR101363296B1 - Method of transmitting demodulation reference signal of fake multimedia broadcasting single frequency network subframe - Google Patents

Abstract

Disclosed are a DM-RS structure and a transmission method of a fake MBSFN subframe for transmitting a physical data sharing channel (PDSCH) on an MBSFN subframe. In the DM-RS transmission of the fake MBSFN subframe according to the present invention, the DM-RS is arranged from the third symbol of the subframe taking advantage of the characteristics of the MBSFN subframe, and in the case of rank 2 transmission, less resource allocation is performed by the CDM multiplexing scheme. In order to enable transmission of the DM-RS, and in the case of rank 4 transmission, the DMM-RS of 4 antennas can be transmitted orthogonally by combining the CDM scheme and the TDM or FDM scheme to maintain compatibility with the rank 2 transmission. In the rank 8 transmission, the orthogonal code having the length of twice the orthogonal code used in the rank 4 transmission has the same overhead as the rank 4 transmission while maintaining the orthogonality between the antennas added and the orthogonality with the antennas belonging to the rank 4 transmission. To be configured. Therefore, even when a PDSCH channel is mapped to a fake MBSFN subframe, efficient DM-RS transmission using the MBSFN subframe can be performed.

Description

DMC-RSS transmission method of fake MBSFN subframe {MULTIMEDIA BEMADULATION REFERENCE SIGNAL OF FAKE MULTIMEDIA BROADCASTING SINGLE FREQUENCY NETWORK SUBFRAME}

The present invention relates to a method of transmitting a demodulation reference signal (DM-RS), and more particularly, to a fake MBSFN sub-map that maps a physical data shared channel (PDSCH) channel to an MBSFN subframe in 3GPP LTE-Advanced. A structure of a DM-RS specialized for a frame and a method of transmitting the same are provided.

As a candidate technology of 4G mobile communication of 3GPP rel-8 Long-Term Evolution (LTE), which has been standardized by 3GPP, LTE-advanced, which is being actively standardized, is transmitted to terminal devices for more efficient downlink resource utilization. It has been decided to map a Physical Data Shared Channel (PDSCH) on a Multimedia Broadcasting Single Frequency Network (MBSFN) subframe.

FIG. 1 is a time-frequency resource arrangement for explaining a downlink CRS structure in which standard work is completed in 3GPP LTE.

FIG. 1 illustrates a frequency-time resource arrangement of one subframe (1ms) composed of two slots (0.5ms) in 3GPP LTE. In FIG. 1, the horizontal axis represents a time axis and the vertical axis represents a frequency axis. .

That is, the vertical axis is for distinguishing OFDM subcarriers arranged in frequency, and the horizontal axis is for discriminating OFDM symbols arranged in time. In the following drawings to have the same horizontal axis, vertical axis arrangement structure.

Referring to FIG. 1, the downlink RS structure of 3GPP LTE is a method of transmitting a cell-specific RS (CRS), and time-frequency in which four antennas are sequentially divided into R1, R2, R3, and R4. An example of being arranged in a resource (RE) is illustrated (Rank 4 transmission). In this way, each antenna transmits RS only to the RE designated for each antenna, and the RS position of the other antenna should be left blank. In this case, the RS sequence used is a pseudo-random sequence generated according to a cell identifier, a slot number, and an OFDM symbol number, and is configured to be changed for each symbol.

Meanwhile, the downlink RS of the current 3GPP LTE has a channel quality (CQI) reported by a demodulation RS (DM-RS) serving as a pilot signal for data demodulation and a user equipment (UE) to a base station (eNB). CSI-RS (Channel state information RS) for channel measurement for generating information is not separately defined, and only CRS is used as a common use of DM-RS and CSI-RS.

The problem of the CRS design was continuously pointed out during the standardization of LTE-advanced, the next version after the standardization of 3GPP LTE. In LTE-advanced, the DM-RS and CSI-RS for data demodulation are separated and received using RS. It was decided to standardize in order to improve the performance and efficiency of the resources required to transmit RS. In late August 2009, the baseline of the DM-RS structure for transmission up to rank 2 of 3GPP RAN WG1 meeting # 58 held in Shenzhen, China was determined.

In addition, in the LTE-advanced standardization process, in order to more efficiently and flexibly utilize downlink resources, physical information about a UE is also performed on a multimedia broadcasting single frequency network (MBSFN) subframe used for multimedia broadcast / multicast service (MBMS) transmission. A decision has been made to enable mapping of a physical data shared channel (PDSCH).

The MBSFN subframe is a subframe configured to have a longer cyclic prefix (CP) length than a normal subframe to accommodate a long delay due to the large coverage for MBMS transmission. The MBSFN subframe is located in an MBMS area where MBSFN transmission is performed. It is configured to inform UEs in advance whether a subframe transmitted in the future is scheduled to a normal subframe or an MBSFN subframe through a system information message broadcasted by existing base stations.

Accordingly, inefficiency of downlink resources occurs that data other than data for MBMS broadcasting for UEs cannot be transmitted within a period in which the MBSFN subframe is transmitted by the base stations existing in the MBMS area. For example, the MBSFN subframe resource is generated because MBMS data is not transmitted and is wasted.

The decision to enable mapping of the PDSCH channel to the UE even on the MBSFN subframe used for the MBMS transmission described above utilizes the MBSFN subframe in which the MBMS data is not filled for more flexible and efficient resource allocation in LTE-advanced. This is to enable data transmission to the terminal. However, despite these discussions and decisions, the DM-RS structure and its transmission method for a subframe (hereinafter, referred to as a 'fake' subframe) in which a PDSCH channel is mapped onto an MBSFN subframe Although not yet determined, it is necessary to determine a new DM-RS structure for the fake MBSFN subframe and its transmission method reflecting the characteristics of the MBSFN subframe different from the structure of the conventional normal subframe.

An object of the present invention is to provide a method of transmitting a demodulation reference signal (DM-RS) suitable for a downlink fake MBSFN subframe of 3GPP LTE-advanced.

In order to achieve the above object of the present invention, DM-RS for rank 2 transmission of a fake MBSFN subframe in which a physical data shared channel (PDSCH) channel is mapped onto a multimedia broadcasting single frequency network (MBSFN) subframe (Demodulation Reference Signal) transmission method, the DM-RS is located from the third symbol of the Fake MBSFN subframe to which the control channel is not mapped, DM-RS of the first antenna and DM-RS of the second antenna is CDM ( A DM-RS transmission method of a fake MBSFN subframe, which is arranged and transmitted in the same resource elements (REs) in a code-division multiplexing (RE) scheme.

In order to achieve the above object of the present invention, DM-RS for rank 4 transmission of a fake MBSFN subframe in which a physical data shared channel (PDSCH) channel is mapped onto a multimedia broadcasting single frequency network (MBSFN) subframe (Demodulation Reference Signal) transmission method, the DM-RS is located from the third symbol of the Fake MBSFN subframe to which the control channel is not mapped, the DM-RS of the first antenna and the DM-RS of the second antenna is CDM ( Code-Division Multiplexing (RE) arranged in the same Resource Element (RE), DM-RS of the third antenna and DM-RS of the fourth antenna is arranged in the same RE in the CDM scheme, the first and second REs in which the DM-RSs of the antennas are arranged and REs in which the DM-RSs of the third and fourth antennas are arranged are orthogonally arranged and transmitted in a frequency division multiplexing (FDM) method or a time division multiplexing (TDM) method. Fake MBSFN Featuring It provides a DM-RS transmission method in the Broken frame.

In order to achieve the above object of the present invention, DM-RS for rank 8 transmission of a fake MBSFN subframe in which a Physical Data Shared Channel (PDSCH) channel is mapped onto a multimedia broadcasting single frequency network (MBSFN) subframe (Demodulation Reference Signal) transmission method, the DM-RS is located from the third symbol of the Fake MBSFN subframe to which the control channel is not mapped, the DM-RS of the first antenna and the DM-RS of the second antenna is CDM ( Code-Division Multiplexing (RE) arranged in the same Resource Element (RE), DM-RS of the third antenna and DM-RS of the fourth antenna is arranged in the same RE in the CDM scheme, DM- of the fifth antenna DM-RSs of the RS and the sixth antenna are REs in which the DM-RSs of the first and second antennas are arranged in a CDM manner so as to be orthogonal to the DM-RSs of the first and second antennas, and orthogonal to each other. Tied four or more, the DM-RS of the first and second antennas are arranged The DM-RS of the seventh antenna and the DM-RS of the eighth antenna are orthogonal to the DM-RSs of the third and fourth antennas and are also orthogonal to each other in a CDM manner. Four or more REs in which the DM-RSs of the third and fourth antennas are arranged are bundled and arranged in the same REs as the REs in which the DM-RSs of the third and fourth antennas are disposed, and the first and second antennas And REs in which the DM-RSs of the fifth and sixth antennas are arranged, and REs in which the DM-RSs of the third, fourth, and seventh and eighth antennas are disposed are frequency division multiplexing (FDM) or time division multiplexing (TDM). In an embodiment, the present invention provides a DM-RS transmission method of a Fake MBSFN subframe, wherein the transmission is orthogonally arranged and transmitted.

In the case of using the DM-RS transmission method according to the present invention as described above, when the data transmission to the terminal using the MBSFN subframe is not filled with MBMS data for more flexible and efficient resource allocation in LTE-advanced In this case, DM-RS transmission using MBSFN subframes can be performed.

FIG. 1 is a time-frequency resource arrangement for explaining a downlink CRS structure in which standard work is completed in 3GPP LTE.
2A to 2C are time-frequency resource configuration diagrams for explaining a rank 2 DM-RS transmission structure of a fake MBSFN subframe according to the present invention.
3A to 3C are time-frequency resource arrangements for explaining the rank 4 DM-RS transmission structure of a fake MBSFN subframe according to the present invention.
4A to 4C are time-frequency resource allocation diagrams for explaining the rank 8 DM-RS transmission structure of a fake MBSFN subframe according to the present invention.

While the invention is susceptible to various modifications and alternative forms, specific embodiments thereof are shown by way of example in the drawings and will herein be described in detail.

It should be understood, however, that the invention is not intended to be limited to the particular embodiments, but includes all modifications, equivalents, and alternatives falling within the spirit and scope of the invention.

The terminology used in this application is used only to describe a specific embodiment and is not intended to limit the invention. Singular expressions include plural expressions unless the context clearly indicates otherwise. In this application, the terms "comprise" or "have" are intended to indicate that there is a feature, number, step, operation, component, part, or combination thereof described in the specification, and one or more other features. It is to be understood that the present invention does not exclude the possibility of the presence or the addition of numbers, steps, operations, components, components, or a combination thereof.

Unless defined otherwise, all terms used herein, including technical or scientific terms, have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. Terms such as those defined in commonly used dictionaries should be interpreted as having a meaning consistent with the meaning in the context of the relevant art and are to be interpreted in an ideal or overly formal sense unless explicitly defined in the present application Do not.

A "terminal" used in the present application includes a mobile station (MS), a user equipment (UE), a user terminal (UT), a wireless terminal, an access terminal (AT), a terminal, a subscriber unit, A subscriber station (SS), a wireless device, a wireless communication device, a wireless transmit / receive unit (WTRU), a mobile node, a mobile, or other terminology. Various embodiments of the terminal may be used in various applications such as cellular telephones, smart phones with wireless communication capabilities, personal digital assistants (PDAs) with wireless communication capabilities, wireless modems, portable computers with wireless communication capabilities, Devices, gaming devices with wireless communication capabilities, music storage and playback appliances with wireless communication capabilities, Internet appliances capable of wireless Internet access and browsing, as well as portable units or terminals incorporating combinations of such functions However, the present invention is not limited thereto.

As used herein, a 'base station' generally refers to a fixed point for communicating with a terminal, and includes a base station, a Node-B, an eNode-B, and a BTS. It may be called other terms such as a transceiver system, an access point.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. In order to facilitate the understanding of the present invention, the same reference numerals are used for the same constituent elements in the drawings and redundant explanations for the same constituent elements are omitted.

Although the exact name is not yet defined for the MBSFN subframe to which the PDSCH channel is mapped, the present invention will be referred to as a 'fake MBSFN subframe' for convenience. The fake MBSFN subframe used hereinafter refers to the MBSFN subframe to which the rel-10 PDSCH channel is mapped according to the determination of 3GPP. However, the technical spirit of the present invention may be applied regardless of the name. Care must be taken.

In the following description, the DM-RS configuration structure of a fake MBSFN subframe applied to 3GPP LTE-advanced, rank 2 transmission for arranging DM-RS while maintaining orthogonality for two antennas, and orthogonality for four antennas It will be described by dividing the rank 4 transmission for arranging DM-RS and the rank 8 transmission for arranging DM-RS by maintaining orthogonality for 8 antennas by maintaining DM.

However, hereinafter, for the convenience of description, the DM-RS arrangement structure will be described by dividing the rank 2 transmission, the rank 4 transmission, and the rank 8 transmission from each other. It should be noted that the basic concepts of transmission through a combination of and FDM or TDM schemes are not limited to the description of the corresponding rank transmission, and may be modified by mutual combination.

Meanwhile, in 3GPP, it is determined that both normal CP (4.7 ms) and extended CP (16.7 ms) can be applied to a fake MBSFN subframe. Accordingly, in FIGS. 2A to 2C, 3A to 3C, and 4A to 4C, a fake MBSFN subframe has a normal CP and thus one slot is composed of seven OFDM symbols. However, extended CP It should be noted that even when a slot has 6 OFDM symbols, it is applicable.

For rank 2 transmission

2A to 2C are time-frequency resource configuration diagrams for explaining a rank 2 DM-RS transmission structure of a fake MBSFN subframe according to the present invention.

2A to 2C, the DM-RS pattern is arranged from the third symbol section of the subframe. In the case of the MBSFN subframe, resources are allocated only to the second symbol interval (for reference, in the case of the MBSFN subframe, the control channel (PDCCH or PHICH) is allocated only to the second symbol interval, and the PDCCH is an uplink resource grant). 1 used only for the grant, and the CRS structure illustrated in FIG. 1 is used as it is for the terminal to measure the channel of the neighbor cells until the second symbol period (not shown in FIGS. 2A to 4C), fake MBSFN The DM-RS pattern for the subframe can be advanced to the second symbol interval. Through this, it is possible to improve the performance of channel estimation by distributing the DM-RS pattern as much as possible on the time axis.

In addition, the DM-RS of the first antenna and the DM-RS of the second antenna are arranged in the same resource elements (REs) by the CDM (Code-Division Multiplexing) scheme and transmitted. Characteristic of the RS transmission pattern.

First, FIG. 2A (CDM pattern # 0) shows a sequence of REs in which DM-RSs are located at the third and fourth symbols of a Fake MBSFN subframe, and a sequence located at the last symbol and the last symbol of the Fake MBSFN subframe. Shows an example of being disposed in the transmitted REs.

Next, FIG. 2B (CDM pattern # 1) shows that DM-RSs are disposed in adjacent REs located in a third symbol of a Fake MBSFN subframe and adjacent REs located in a symbol immediately before the last of the Fake MBSFN subframe and transmitted. An example is shown.

Finally, FIG. 2C (CDM pattern # 2) shows REs located in the third symbol of the first slot (even number slot) in which DM-RSs constitute the Fake MBSFN subframe, and REs located in the last symbol of the first slot; FIG. 3 shows an example in which the REs located in the third or fourth symbol of the second number slot and the REs of the last symbol of the second slot are transmitted. At this time, considering that the DM-RS is disposed in a balanced manner, either of the REs located in the third symbol or the fourth symbol of the second slot may be used.

However, as mentioned above, FIG. 2C is a subframe having a normal CP and assumes a case in which one slot is composed of seven symbols. In the case of a subframe having an extended CP, FIG. It would be desirable for the -RS to be deployed and transmitted.

Meanwhile, in the case of the DM-RS transmission pattern illustrated in FIG. 2C, two REs that are continuous in time or not adjacent in frequency should be collected and despreaded, and accordingly, an average channel estimation result is generated, thereby changing the channel state. There may be a limitation that it is suitable for a terminal having a low mobility (mobility) with almost no.

For rank 4 transmission

3A to 3C are time-frequency resource arrangements for explaining the rank 4 DM-RS transmission structure of a fake MBSFN subframe according to the present invention.

As in the case of the previous rank 2 transmission (FIGS. 2A to 2C), a characteristic point of the DM-RS structure of FIGS. 3A to 3C is that the DM-RS pattern can be arranged in the third symbol section of the subframe. Through this, it is possible to improve the performance of channel estimation by distributing the DM-RS pattern as much as possible on the time axis.

In the rank 4 DM-RS transmission structure of FIGS. 3A to 3C, the DM-RS of the first antenna and the DM-RS of the second antenna are arranged in the same resource elements (REs) in a code-division multiplexing (CDM) scheme. The DM-RS of the third antenna and the DM-RS of the fourth antenna are arranged in the same REs in the CDM scheme, and the REs in which the DM-RSs of the first and second antennas are arranged, and the third and fourth The REs in which the DM-RSs of the antennas are arranged are arranged to be orthogonally arranged and transmitted in a frequency division multiplexing (FDM) scheme or a time division multiplexing (TDM) scheme.

Hereinafter, since the description of the transmission structure illustrated in FIGS. 3A to 3C is the same as the description of the transmission structure illustrated in FIGS. 2A to 2C described above, a detailed description thereof will be omitted. That is, the DM-RS transmission for the first and second antennas is the same as for the Rank 2 transmission, and the DM-RS transmission for the third and fourth antennas is the DM-RS for the first and second antennas of the Rank 2 transmission. It is added in a similar way to RS transmission.

However, in order to maintain compatibility with the case of rank 2 transmission illustrated in FIGS. 2A to 2C, DM-RSs for the additional two antennas (third and fourth antennas) are DM-RS and FDM of the first and second antennas. An additional feature is that they are arranged orthogonally in a TDM manner or a TDM manner.

For rank 8 transfers

4A to 4C are time-frequency resource allocation diagrams for explaining the rank 8 DM-RS transmission structure of a fake MBSFN subframe according to the present invention.

As in the case of the previous rank 2 transmission and the rank 4 transmission (FIGS. 2A to 2C and 3A to 3C), the characteristic of the DM-RS structure of FIGS. 4A to 4C is that the DM-RS pattern is the third of the subframe. It can be placed in the symbol section.

Even in the case of rank 8 transmission, it can be seen that the DM-RS transmission of the first to fourth antennas maintains the same compatibility as the rank 4 transmission. That is, the DM-RS of the first antenna and the DM-RS of the second antenna are arranged in the same resource elements (REs) in a code-division multiplexing (CDM) scheme, and the DM-RS of the third antenna and the fourth antenna The DM-RS is placed in the same REs in the CDM manner.

In addition, the DM-RS of the fifth antenna and the DM-RS of the sixth antenna are orthogonal to the DM-RSs of the first and second antennas and are also orthogonal to each other. Four or more REs in which the DM-RSs are arranged are bundled, and the DM-RSs of the first and second antennas are arranged in the same REs as the REs in which the DM-RSs are arranged.

That is, the DM-RSs of the fifth and sixth antennas are orthogonal to each other using an orthogonal code having a double length of the orthogonal code used to make the DM-RSs of the first and second antennas orthogonal to each other. . In this case, the orthogonal code used to orthogonally cross the DM-RSs of the first and second antennas may be configured as a subset of the orthogonal code tree used to orthogonally cross the fifth and sixth antennas. It should be made to maintain orthogonality between DM-RSs of the first and second antennas and the fifth and sixth antennas. Hereinafter, the description of the DM-RS of the seventh antenna and the DM-RS of the eighth antenna may be described similarly to the description of the DM-RS of the fifth and sixth antennas, and thus the description thereof will be omitted.

Similarly, the REs in which the DM-RSs of the first, second, and fifth antennas are arranged, and the REs in which the DM-RSs of the third, fourth, and seventh and eighth antennas are arranged are FDM schemes (FIG. 4A). 4C) or TDM (FIG. 4B) orthogonally arranged and transmitted.

It will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention as defined in the appended claims. It will be possible.

Claims (12)

A method of transmitting a demodulation reference signal (DM-RS) for rank 2 transmission of a fake MBSFN subframe in which a physical data shared channel (PDSCH) channel is mapped on a multimedia broadcasting single frequency network (MBSFN) subframe, The DM-RS is located from the third symbol of the Fake MBSFN subframe to which a channel is not mapped.
DM-RS transmission of a Fake MBSFN subframe, wherein the DM-RS of the first antenna and the DM-RS of the second antenna are arranged and transmitted in the same resource elements (REs) in a code-division multiplexing (CDM) scheme. Way. The method of claim 1,
The DM-RSs are disposed and transmitted in consecutive REs located in the third and fourth symbols of the Fake MBSFN subframe, and consecutive REs located in the last symbol and the last symbol of the Fake MBSFN subframe. DM-RS transmission method of Fake MBSFN subframe. The method of claim 1,
The DM-RSs are disposed and transmitted in successive REs on a frequency axis located in a third symbol of a Fake MBSFN subframe and on consecutive frequency axes located in a symbol immediately before the last symbol of the Fake MBSFN subframe. DM-RS transmission method of Fake MBSFN subframe. The method of claim 1,
The DM-RSs include the REs located in the third symbol of the first slot and the REs located in the last symbol of the first slot, the REs located in the third symbol or the fourth symbol of the second slot constituting the Fake MBSFN subframe. DM-RS transmission method of a Fake MBSFN subframe, characterized in that located in the REs of the last symbol of the second slot. A method of transmitting a demodulation reference signal (DM-RS) for rank 4 transmission of a fake MBSFN subframe in which a physical data shared channel (PDSCH) channel is mapped on a multimedia broadcasting single frequency network (MBSFN) subframe, and is controlled. The DM-RS is located from the third symbol of the Fake MBSFN subframe to which a channel is not mapped.
The DM-RS of the first antenna and the DM-RS of the second antenna are arranged in the same resource elements (REs) in a code-division multiplexing (CDM) scheme, and the DM-RS of the third antenna and the DM-RS of the fourth antenna are RS is placed in the same REs in CDM manner,
REs in which the DM-RSs of the first and second antennas are arranged and REs in which the DM-RSs of the third and fourth antennas are arranged are orthogonal in a frequency division multiplexing (FDM) method or a time division multiplexing (TDM) method. DM-RS transmission method of the Fake MBSFN subframe, characterized in that arranged and transmitted. The method of claim 5, wherein
The DM-RSs are disposed and transmitted in consecutive REs located in the third and fourth symbols of the Fake MBSFN subframe, and consecutive REs located in the last symbol and the last symbol of the Fake MBSFN subframe. DM-RS transmission method of Fake MBSFN subframe. The method of claim 5, wherein
The DM-RSs are disposed and transmitted in successive REs on a frequency axis located in a third symbol of a Fake MBSFN subframe and on consecutive frequency axes located in a symbol immediately before the last symbol of the Fake MBSFN subframe. DM-RS transmission method of Fake MBSFN subframe. The method of claim 5, wherein
The DM-RSs include the REs located in the third symbol of the first slot and the REs located in the last symbol of the first slot, the REs located in the third symbol or the fourth symbol of the second slot constituting the Fake MBSFN subframe. DM-RS transmission method of a Fake MBSFN subframe characterized in that the transmission is arranged in the REs located in the last symbol of the second slot. A method of transmitting a demodulation reference signal (DM-RS) for transmitting rank 8 of a fake MBSFN subframe in which a physical data shared channel (PDSCH) channel is mapped on a multimedia broadcasting single frequency network (MBSFN) subframe, The DM-RS is located from the third symbol of the Fake MBSFN subframe to which a channel is not mapped.
The DM-RS of the first antenna and the DM-RS of the second antenna are arranged in the same resource elements (REs) in a code-division multiplexing (CDM) scheme, and the DM-RS of the third antenna and the DM-RS of the fourth antenna are RS is placed in the same REs in CDM manner,
The DM-RS of the fifth antenna and the DM-RS of the sixth antenna are orthogonal to the DM-RSs of the first and second antennas, and are also orthogonal to each other. Four or more REs arranged with the RS are bundled, and the DM-RSs of the first and second antennas are arranged in the same REs as the arranged REs, and the DM-RS of the seventh antenna and the DM-RS of the eighth antenna are And tying four or more REs in which the DM-RSs of the third and fourth antennas are arranged in a CDM manner so as to be orthogonal to the DM-RSs of the third and fourth antennas, and orthogonal to each other. The DM-RS of the antenna is placed in the same REs as the deployed REs,
REs in which the DM-RSs of the first, second, and fifth and sixth antennas are arranged, and REs in which the DM-RSs of the third, fourth, and seventh and eighth antennas are arranged are frequency division multiplexing (FDM) schemes. Or DM-RS transmission method of a fake MBSFN subframe, characterized in that orthogonally arranged and transmitted in a time division multiplexing (TDM) scheme. The method of claim 9,
The DM-RSs are disposed and transmitted in consecutive REs located in the third and fourth symbols of the Fake MBSFN subframe, and consecutive REs located in the last symbol and the last symbol of the Fake MBSFN subframe. DM-RS transmission method of Fake MBSFN subframe. The method of claim 9,
The DM-RSs are disposed and transmitted in successive REs on a frequency axis located in a third symbol of a Fake MBSFN subframe and on consecutive frequency axes located in a symbol immediately before the last symbol of the Fake MBSFN subframe. DM-RS transmission method of Fake MBSFN subframe. The method of claim 9,
The DM-RSs include the REs located in the third symbol of the first slot and the REs located in the last symbol of the first slot, the REs located in the third symbol or the fourth symbol of the second slot constituting the Fake MBSFN subframe. DM-RS transmission method of a Fake MBSFN subframe characterized in that the transmission is arranged in the REs located in the last symbol of the second slot.

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