KR20150090585A - Apparatus and method for determining uplink demodulation-reference signal sequence - Google Patents

Abstract

Disclosed are a method and an apparatus for determining an uplink demodulation - reference signal (DM-RS) sequence. According to the present invention, the method for determining the reduced DM-RS sequence comprises: a step in which a terminal receives information on the number of resource blocks allocated for the uplink DM-RS sequence reduced in a single slot of an uplink sub-frame; and a step in which the terminal determines the uplink DM-RS sequence to be mapped to the uplink sub-frame based on information on the number of the allocated recourse blocks, wherein the reduced uplink DM-RS sequence includes first and second reduced uplink DM-RS sequences which are generated based on a first circulation shift field value when the number of the allocated resource blocks is an even number, and the reduced uplink DM-RS sequence includes third and fourth reduced uplink DM-RS sequences which are generated based on a first circulation shift field value when the number of the allocated resource blocks is an odd number.

Description

[0001] APPARATUS AND METHOD FOR DETERMINING UPLINK DEMODULATION-REFERENCE SIGNAL SEQUENCE [0002]

The present invention relates to wireless communication, and more particularly, to a method and apparatus for determining a reference signal used in a wireless communication system supporting a small cell.

In a next generation communication system such as LTE-A (Advanced), a small cell based on a low-power node as well as a macro cell based on a high-power node (F2 Research is underway to provide wireless communication services indoors and outdoors through the Internet.

The small cell can be considered both in the frequency band that is the coverage of the macrocell and in the frequency band other than the coverage of the macrocell, and can be provided both in the indoor environment (in the cube) and in the outdoor environment (outside the cube). Also, an ideal or non-ideal backhaul network may be supported between macrocells and small cells, and / or between small cells. And the small cell can be provided both in a low density sparse deployment environment and / or a dense deployment environment.

SUMMARY OF THE INVENTION The present invention provides a method for determining an uplink DM-RS sequence.

Another aspect of the present invention is to provide an apparatus for performing a method for determining an uplink DM-RS sequence.

According to another aspect of the present invention, there is provided a method of determining a downlink DM (demodulation) -RS (reference signal) sequence, the method comprising: Receiving information on the number of resource blocks (s) allocated for the uplink DM-RS sequence based on information on the number of allocated resource blocks, RS sequence to be mapped to a link sub-frame, wherein if the number of allocated resource block (s) is an even number, the reduced uplink DM-RS sequence may include a first cyclic A first reduced uplink DM-RS sequence and a second reduced uplink DM-RS sequence generated based on a value of a shift field, and when the number of the allocated resource block (s) is an odd number,The reduced uplink DM-RS sequence includes a third reduced uplink DM-RS sequence and a fourth reduced uplink DM-RS sequence generated based on the value of the first cyclic shift field, If the number of the resource block (s) is even, the value of the first cyclic shift field is used to generate the first reduced uplink DM-RS sequence and the second reduced uplink DM-RS sequence (CS) determination value and a first orthogonal sequence based on a downlink control field (DCI), and when the number of allocated resource blocks is an odd number, a value of the first cyclic shift field Determines a second DCI-based CS decision value and a second orthogonal sequence for generating the third reduced uplink DM-RS sequence and the fourth reduced uplink DM-RS sequence, and wherein the first DCI based CS The decision value and the first orthogonal sequence are different from each other RS sequences and the second reduced uplink DM-RS sequences transmitted in the second DCI-based sequence are orthogonal to each other, the second reduced DC-RS sequence is determined to be orthogonal to the second reduced DC- CS decision value and the second orthogonal sequence are generated by combining the remaining reduced uplink DM-RS sequence transmitted in the other layer with each of the third reduced uplink DM-RS sequence and the fourth reduced uplink DM- The length of the first reduced uplink DM-RS sequence and the length of the second reduced uplink DM-RS sequence are each a multiple of 12, and the third reduced uplink DM-RS The length of the sequence and the length of the fourth reduced uplink DM-RS sequence may each be a multiple of six.

According to another aspect of the present invention, there is provided a terminal for performing an uplink DM (demodulation) -RS (reference signal) sequence determination method, And a processor selectively coupled to the RF unit, the processor comprising: a resource block allocated for the reduced uplink DM-RS sequence in one slot of the uplink sub-frame; RS to be mapped to the uplink sub-frame based on the information on the number of the resource block (s) allocated to the resource block (s) RS, the reduced uplink DM-RS sequence may include a first cyclic shift field generated based on the value of the first cyclic shift field, if the number of allocated resource blocks is an even number, RS sequence and a second reduced uplink DM-RS sequence, wherein if the number of allocated resource block (s) is an odd number, the reduced uplink DM-RS sequence includes the first A third reduced uplink DM-RS sequence generated based on the value of the cyclic shift field, and a fourth reduced uplink DM-RS sequence generated based on the value of the cyclic shift field, and when the number of allocated resource blocks is an even number, Wherein the value of the first cyclic shift field comprises a first downlink control field (DCI) based cyclic shift (CS) to generate the first reduced uplink DM-RS sequence and the second reduced uplink DM-RS sequence, And determining a first orthogonal sequence and a first orthogonal sequence if the number of allocated resource blocks is an odd number, the value of the first cyclic shift field is determined by the third reduced uplink DM-RS sequence And the fourth reduced uplink DM-RS sequence Wherein the first DCI-based CS decision value and the first orthogonal sequence are combined with the remaining reduced uplink DM-RS sequences transmitted on the different layer and the second DCI-based CS decision value and the second orthogonal sequence, respectively, RS sequence and the second reduced uplink DM-RS sequence of the second DCI-based CS decision value and the second orthogonal sequence are orthogonal, and the second DCI-based CS decision value and the second orthogonal sequence of the second reduced uplink DM- RS sequence and each of the third reduced uplink DM-RS sequence and the fourth reduced uplink DM-RS sequence are orthogonal, the first reduced uplink DM-RS sequence is determined to be orthogonal to the second reduced uplink DM- RS sequence and a length of the second reduced uplink DM-RS sequence are respectively a multiple of 12, the length of the third reduced uplink DM-RS sequence and the length of the fourth reduced uplink DM- The length of It may be multiples of each six.

In the small cell environment, the UE can newly define resources allocated for transmitting a reference signal and perform uplink transmission. By controlling the resources allocated to the uplink DM-RS in consideration of the channel environment of the small cells, it is possible to reduce the overhead of the uplink DM-RS, thereby increasing the data transmission efficiency of the UE in the small cell. In addition, even though the amount of resources used to transmit the uplink DM-RS is reduced, the number of uplink DM-RSs in a plurality of terminals and / or a plurality of layers can be reduced by applying OCC to each reference signal sequence. The orthogonality between the sequences can be guaranteed.

1 is a block diagram illustrating a wireless communication system to which the present invention is applied.
2 and 3 schematically show the structure of a radio frame to which the present invention is applied.
4 is a conceptual diagram illustrating transmission of an uplink DM-RS when a PUSCH is transmitted.
5 is a conceptual diagram showing that one basic reference signal sequence is generated as a plurality of reference sequences according to a cyclic shift.
6 shows an uplink DM-RS generated using an orthogonal cover code.
7 is a conceptual diagram showing a small cell environment.
8 is a conceptual diagram illustrating a method of mapping an uplink DM-RS sequence according to an embodiment of the present invention.
9 is a conceptual diagram illustrating a method of mapping an uplink DM-RS sequence according to an embodiment of the present invention.
10 is a conceptual diagram illustrating a method of mapping an uplink DM-RS sequence according to an embodiment of the present invention.
11 is a conceptual diagram illustrating a method of mapping an uplink DM-RS sequence according to an embodiment of the present invention.
12 is a conceptual diagram illustrating a method for ensuring orthogonality between layers and / or terminals according to an embodiment of the present invention.
13 is a conceptual diagram illustrating a method for ensuring orthogonality between layers and / or terminals according to an embodiment of the present invention.
FIG. 14 is a conceptual diagram illustrating a method for ensuring orthogonality between layers and / or terminals according to an embodiment of the present invention.
15 is a block diagram illustrating a wireless communication system according to an embodiment of the present invention.

Hereinafter, some embodiments will be described in detail with reference to exemplary drawings. It should be noted that, in adding reference numerals to the constituent elements of the drawings, the same constituent elements are denoted by the same reference symbols as possible even if they are shown in different drawings. In the following description of the embodiments 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 disclosure rather unclear.

The present invention will be described with reference to a communication network. The work performed in the communication network may be performed in a process of controlling the network and transmitting data by a system (e.g., a base station) that manages the communication network, The work can be done.

1 is a block diagram illustrating a wireless communication system to which the present invention is applied.

Referring to FIG. 1, a wireless communication system 10 is widely deployed to provide various communication services such as voice, packet data, and the like. The wireless communication system 10 includes at least one base station 11 (BS). Each base station 11 provides communication services for a particular geographical area or frequency domain and may be referred to as a site. A site may be divided into a plurality of areas 15a, 15b, and 15c, which may be referred to as sectors, and the sectors may have different cell IDs.

A user equipment (UE) 12 may be fixed or mobile and may be a mobile station (MS), a mobile terminal (MT), a user terminal (UT), a subscriber station (SS), a wireless device, (personal digital assistant), a wireless modem, a handheld device, and the like. The base station 11 generally refers to a station that communicates with the terminal 12 and includes an evolved-NodeB (eNodeB), a base transceiver system (BTS), an access point, a femto base station (Femto eNodeB) (ENodeB), a relay, a remote radio head (RRH), and the like. The cells 15a, 15b and 15c should be interpreted in a comprehensive sense to indicate a partial area covered by the base station 11 and include all coverage areas such as megacell, macrocell, microcell, picocell, femtocell to be.

Hereinafter, a downlink refers to a communication or communication path from the base station 11 to the terminal 12, and an uplink refers to a communication or communication path from the terminal 12 to the base station 11 . In the downlink, the transmitter may be part of the base station 11, and the receiver may be part of the terminal 12. In the uplink, the transmitter may be part of the terminal 12, and the receiver may be part of the base station 11. There is no limit to the multiple access scheme applied to the wireless communication system 10. [ (CDMA), Time Division Multiple Access (TDMA), Frequency Division Multiple Access (FDMA), Orthogonal Frequency Division Multiple Access (OFDMA), Single Carrier-FDMA , OFDM-CDMA, and the like. These modulation techniques increase the capacity of the communication system by demodulating signals received from multiple users of the communication system. The uplink transmission and the downlink transmission may be performed using a time division duplex (TDD) scheme transmitted at different times or a frequency division duplex (FDD) scheme using different frequencies.

The layers of the radio interface protocol between the terminal and the base station are divided into a first layer (L1), a second layer (L1), and a second layer (L2) based on the lower three layers of an Open System Interconnection A second layer (L2), and a third layer (L3). Among them, the physical layer belonging to the first layer provides an information transfer service using a physical channel.

There are several physical channels used in the physical layer. The physical downlink control channel (PDCCH) includes a resource allocation and transmission format of a downlink shared channel (DL-SCH), a resource of an uplink shared channel (UL-SCH) Resource allocation of an upper layer control message such as allocation information, a random access response transmitted on a physical downlink shared channel (PDSCH), transmission power control for individual terminals in an arbitrary terminal group : TPC) commands, and so on. A plurality of PDCCHs can be transmitted in the control domain, and the UE can monitor a plurality of PDCCHs.

Control information of the physical layer mapped to the PDCCH is referred to as downlink control information (DCI). That is, the DCI is transmitted on the PDCCH. The DCI may include an uplink or downlink resource allocation field, an uplink transmission power control command field, a control field for paging, a control field for indicating a random access response (RA response), and the like.

2 and 3 schematically show the structure of a radio frame to which the present invention is applied.

Referring to FIGS. 2 and 3, a radio frame includes 10 subframes. One subframe includes two slots. The time (length) for transmitting one subframe is called a transmission time interval (TTI). Referring to FIG. 2, for example, the length of one subframe (1 subframe) may be 1 ms and the length of one slot may be 0.5 ms.

A slot may contain a plurality of symbols in the time domain. For example, in the case of a radio system using OFDMA in a downlink (DL), the symbol may be an Orthogonal Frequency Division Multiplexing (OFDM) In the case of a radio system using Single Carrier-Frequency Division Multiple Access (FDMA), the symbol may be a Single Carrier-Frequency Division Multiple Access (SC-FDMA) symbol. On the other hand, the representation of the symbol period of the time domain is not limited by the multiple access scheme or the name.

The number of symbols included in one slot may vary according to the length of a CP (Cyclic Prefix). For example, one slot may include seven symbols in the case of a normal CP, and one slot may include six symbols in the case of an extended CP.

A resource block (RB) is a resource allocation unit, which includes time-frequency resources corresponding to 180 kHz on the frequency axis and 1 slot on the time axis. A resource element (RE) represents a smallest time-frequency unit to which a modulation symbol of a data channel or a modulation symbol of a control channel is mapped.

In a wireless communication system, it is necessary to estimate an uplink channel or a downlink channel for data transmission / reception, system synchronization acquisition, channel information feedback, and the like. A process of compensating for a distortion of a signal caused by a sudden change in channel environment and restoring a transmission signal is called channel estimation. It is also necessary to measure the channel state of the cell or other cell to which the terminal belongs. In general, a reference signal (RS) known between a UE and a transmission / reception point is used for channel estimation or channel state measurement.

In the case of the downlink channel estimation, since the UE knows the information of the reference signal, the UE estimates the channel based on the received reference signal and compensates the channel value so that the data transmitted from the base station can be accurately obtained. If the reference signal sent from the base station is p, the channel information experienced by the reference signal during transmission is h, the thermal noise generated by the terminal is n, and the signal received by the terminal is y, y = h p + n . Since the reference signal p is already known by the UE, if the LS (Least Square) scheme is used, the channel information

) Can be estimated.

&Quot; (1) "

Here, the channel estimation value estimated using the reference signal p

The

Value, so for accurate estimation of the h value

It is necessary to converge to zero.

In the case of the uplink channel estimation, similar to the downlink channel estimation described above, except that the transmitting entity of the reference signal is the terminal and the receiving entity is the base station.

The reference signal is typically generated by generating a signal from a sequence of reference signals. The reference signal sequence may be one or more of several sequences having superior correlation characteristics. For example, a Constant Amplitude Zero Auto-Correlation (CAZAC) sequence such as a Zadoff-Chu (ZC) sequence or a PN (pseudo-noise) sequence such as an m-sequence, a Gold sequence or a Kasami sequence May be used as the reference signal sequence, and various other sequences having superior correlation characteristics may be used depending on system conditions. The reference signal sequence may be cyclic extension or truncation to adjust the length of the sequence or may be used in various forms such as binary phase shift keying (BPSK) or quadrature phase shift keying (QPSK) And may be mapped to a RE (Resource element).

The downlink reference signal includes a cell-specific RS, a MBSFN reference signal, a UE-specific RS, a position reference signal PRS, RS and a channel state information (CSI) reference signal (CSI-RS).

The UE-specific reference signal is a reference signal received by a specific UE or a specific UE group in a cell and can be called a Demodulation RS (DM-RS) since it is mainly used for data demodulation of a specific UE or a specific UE group. have.

Similar to the downlink, the reference signal is also transmitted in the LTE uplink. In the LTE uplink, the uplink DM-RS and SRS can be used. The uplink DM-RS can be used by the base station for channel estimation for coherent demodulation of uplink physical channels (PUSCHs) and physical uplink control channels (PUCCHs) . Therefore, the uplink DM-RS is always transmitted as PUSCH or PUCCH and can be transmitted with the same bandwidth as the corresponding physical channels.

The uplink SRS can be used for channel estimation for channel dependent scheduling and link adaptation according to the uplink channel. The SRS can also be used for estimating the channel condition of the downlink when there is sufficient reciprocity between the uplink and downlink, that is, when the uplink and downlink channels exhibit sufficiently similar characteristics.

Hereinafter, in the embodiment of the present invention, the uplink DM-RS is additionally posted.

The uplink DM-RS is used for channel estimation for the coherent demodulation of the PUSCH to which the UL-SCH transport channel is mapped and for the coherent demodulation of the PUCCH that carries various types of L1 / L2 control signaling need. Although there are some differences, the basic uplink DM-RS structure can be the same for PUSCH and PUCCH. The difference is that the number and position of the SC-FDMA symbols transmitting the reference signal in one subframe may be different from each other.

4 is a conceptual diagram illustrating transmission of an uplink DM-RS when a PUSCH is transmitted.

Referring to FIG. 4, certain symbols may be used solely to transmit the uplink DM-RS. Therefore, the uplink reference signal is time multiplexed with other uplink transmissions from the same terminal. More specifically, in case of PUSCH transmission, the uplink DM-RS can be transmitted in the fourth symbol from the back of each uplink slot. That is, in the case of a normal CP, it can be transmitted in the fourth symbol (l = 3) from the beginning of each uplink slot. In case of an extended CP, a third symbol (l = 2). ≪ / RTI >

Thus, within a subframe, there may be a total of two transmissions of the reference signal once per slot.

In the case of PUCCH transmission, the number of symbols used for reference signal transmission and the exact positions of symbols used for transmission of reference signals in a slot may vary according to the PUCCH format. The basic structure of each reference signal transmission may be a frequency-domain reference signal mapped to a continuous input (continuous subcarrier) of the signal generator, irrespective of whether the type of uplink transmission is PUCCH or PUSCH. The bandwidth of the reference signal corresponding to the sequence length of the reference signal may be equal to the transmission bandwidth of the PUSCH / PUCCH measured by the number of subcarriers. This means that in the case of PUSCH transmission, it is necessary to be able to generate reference signal sequences of different lengths corresponding to possible PUSCH transmission bandwidths. Since the uplink resource allocation for PUCSH transmission is always performed in units of resource blocks having 12 subcarriers, the length of the sequence of reference signals may be a multiple of 12 as well.

Hereinafter, a method of generating a reference signal sequence of an uplink DM-RS (demodulation reference signal for PUSCH) for PUCSH will be described in detail. That is, in the embodiment of the present invention, the uplink DM-RS that is posted may indicate the uplink DM-RS with respect to the PUSCH.

The sequence of the uplink DM-RS for the PUSCH is

As a layer

Can be defined as shown in Equation (2) below.

&Quot; (2) "

Referring to Equation 2,

Denotes the length of the reference signal sequence as the number of subcarriers allocated for the reference signal sequence.

, ≪ / RTI >

Is the number of subcarriers included in one resource block. m is the number of the resource block (s) allocated for the PUSCH and the uplink DM-RS associated therewith

(Where m in Equation 2 is an index of an orthogonal sequence having a value of 0 or 1, and m (m) corresponding to the number of allocated resource block (s) It is a different parameter from. As described above, the length of the reference signal sequence may be defined as a multiple of the number of subcarriers included in one resource block.

It can be seen that the number of subcarriers allocated for the reference signal sequence corresponding to the length of the reference signal sequence is equal to the number of subcarriers allocated to the PUSCH.

≪ RTI ID = 0.0 >

The

. ≪ / RTI >

Is a cyclic shift,

And basic sequence

Lt; / RTI > The following equation (3)

.

&Quot; (3) "

As described above

Is the length of the reference signal sequence. Cyclic shift

According to one basic sequence

May be defined as a plurality of reference signal sequences.

Basic sequence

Can be defined by the Zadoff-Chu sequence. The definition of this basic sequence is described in 3GPP TS36.211 V11.4.0, 3rd Generation Partnership Project Technical Specification Group Radio Access Network Evolved Universal Terrestrial Radio Access (E-UTRA) Physical Channels and Modulation (Release 11 ) (Hereinafter referred to as 3GPP TS36.211).

5 is a conceptual diagram showing that one basic reference signal sequence is generated as a plurality of reference sequences according to a cyclic shift.

The uplink DM-RSs defined from different reference signal sequences generally have a non-zero cross-correlation, albeit relatively low. On the other hand, the reference signals defined by different phase rotations of the same basic reference signal sequence are orthogonal to each other and do not interfere with each other. E.g

Changes from 0 to 11, the cyclic shift

The value of

The reference signal sequence orthogonal to each other can be generated according to the change of the cyclic shift based on one basic sequence. That is, up to twelve orthogonal reference signals can be defined from one basic sequence.

Referring again to Equation (2)

Represents an orthogonal sequence such as an orthogonal cover code (OCC). Hereinafter, in an embodiment of the present invention, an orthogonal sequence may be defined and used in terms of an orthogonal cover code or OCC.

The orthogonal sequence can be used in a multiple antenna precoding scheme including uplink multiple antenna transmission, specifically spatial multiplexing. When spatial multiplexing is performed, a separate uplink DM-RS is required per layer. For example, if it is necessary to support simultaneous transmission of four spatially multiplexed layers, one terminal must be able to transmit four different uplink DM-RSs. In order to generate such different uplink DM-RSs, a plurality of mutually orthogonal reference signals are generated using different cyclic sequences as described above, or an orthogonal cover code is generated for two reference signal transmissions in a subframe code to generate two different reference signals.

6 shows an uplink DM-RS generated using an orthogonal cover code.

6 is the uplink DM-RS generated when the orthogonal cover code is [+1, +1] and the lower end of FIG. 6 is the uplink DM generated when the orthogonal cover code is [+1, -1] -RS. The plurality of orthogonal reference signals generated in this manner may be used, for example, in performing a multiple input multiple output (MIMO) -multiple input multiple output (MIMO).

If the upper layer parameter Activate-DMRS-with-OCC is not set or the temporary uplink-related DCI for the transport block associated with the corresponding PUSCH transmission is transmitted, When a temporary cell radio network identifier (RNTI) is used, the orthogonal sequence < RTI ID = 0.0 >

For the downlink control information (DCI) format 0,

. ≪ / RTI >

Otherwise, the orthogonal sequence

May be given by Table 1 below using the cyclic shift field of the most recent uplink-related DCI for the transport block associated with the corresponding PUSCH transmission.

<Table 1>

In Equation 2,

(Cyclic shift)

Slot

in

Can be defined as

Can be defined as Equation (4) below.

&Quot; (4) &quot;

In Equation 4,

Can be determined according to the value of the cyclic shift as shown in Table 2 below.

<Table 2>

Can be determined by the cyclic shift field in the uplink-related DCI format as shown in Table 1 above.

Can be determined by the following equation (5).

&Quot; (5) &quot;

In Equation (5), a pseudo-random sequence c (i) is defined by a Gold sequence of length 31 as follows.

&Quot; (6) &quot;

Here, Nc = 1600, the first m-sequence is initialized to x1 (0) = 1, x1 (n) = 0, n = 1,2, ..., The second m-sequence is transmitted at the beginning of each radio frame

Lt; / RTI &gt; If the upper layer

Or a retransmission of the same transport block as part of a random access grant or a contention based random access procedure is associated with a PUSCH transmission

The

Lt; / RTI &gt;

Is the physical cell identifier (PCI) of the cell. Otherwise

Lt; / RTI &gt;

Hereinafter, in the embodiment of the present invention, an uplink-related DCI format is posted.

DCI format 0 or DCI format 4 may be used for the scheduling of the PUSCH in one uplink cell. DCI format 4 was added in release 10 to support UL spatial multiplexing. The basis of the uplink resource allocation scheme is a single cluster scheme in which all of the resource block (s) are continuous in the frequency domain, but in release 10, transmission to a maximum of two clusters per component carrier And a multi-cluster scheme supporting the same.

DCI format 0 can be used to schedule uplink transmissions when spatial multiplexing on a component carrier is not used and has the same size as a control signaling message of compact downlink allocation (DCI Format 1A). The flag on the message may inform the UE about whether it is an uplink scheduling grant (DCI format 0) or a downlink scheduling assignment (DCI format 1A).

The information included in DCI format 0 and DCI format 4 is &quot; 3GPP TS36.212 V11.3.0, 3rd Generation Partnership Project; Technical Specification Group Radio Access Network; Evolved Universal Terrestrial Radio Access (E-UTRA); 5.3.3.1.1 FORMAT 0, 5.3.3.1.8 FORMAT 4 of Multiplexing and channel coding (Release 11) '(hereinafter 3GPP TS36.212). The information contained in each DCI format is shown below.

The DCI format 0 includes a carrier indicator, a DCI format differentiation flag, a frequency hopping flag, a resource block allocation and hopping resource a TPC command for a scheduled PUSCH, a cyclic shift and a cyclic shift for a DM-RS and an RNC, OCC index, UL index, downlink assignment index, CSI request, SRS request, resource allocation type, etc. . &Lt; / RTI &gt;

DCI format 4 can be used in the case of uplink transmission using spatial multiplexing on one component carrier.

DCI format 4 includes a carrier indicator, a resource block assignment, a PUSCH power for information (TPC command for PUSCH), cyclic shift and orthogonal code information (cyclic shift for DM-RS and OCC index) A UL index, a downlink assignment index, a CSI request, an SRS request, a resource allocation type, a transport block, Modulation and coding scheme (MCS) and new data indicator (NDI) information for each of the transport blocks 1 and / or 2.

Also, the DCI format 4 may include precoding information, and the precoding information may include information on the number of transmitted precoding matrix indicators (TPMI) and layers.

Table 3 below shows the number of bits allocated to the precoding information according to the number of antenna ports of the UE.

<Table 3>

The information included in the precoding information may be defined differently depending on the number of the antenna ports of the UE, and the number of the precoding matrix indicator and the layer transmitted.

Table 4 below shows the number of precoding matrix indicators and layers included in the precoding information when there are two antenna ports.

<Table 4>

Table 5 below shows the number of precoding matrix indicators and layers included in the precoding information when there are four antenna ports.

<Table 5>

Referring to Table 4 and Table 5, the precoding matrix indicator and the number of layers can be determined according to the value of the bits mapped to the precoding information.

7 is a conceptual diagram showing a small cell environment.

7, in 3GPP, a feasibility study for improving the technology of a small base station (eNodeB), which can be used to cover a small area compared with existing macro base stations, is performed among various technical standard items .

Referring to FIG. 7, the base station can be classified into a macro, a pico, a femto base station, or the like depending on the size of a coverage area. The macro base station may be a base station which is generally used and which covers a wider area than a pico base station. Therefore, the macro base station can use a relatively stronger power in transmission than the pico base station. A pico base station covers a small area for a hotspot or a coverage hole. Also, in general, the pico base station can use relatively less power than the macro base station. Therefore, the connection reliability of the pico base station may be lower than that of the macro base station. In 3GPP, a cell provided by a small base station, such as a pico base station, is called a small cell 750 in comparison with a macro base station. Research is underway on various schemes that can more efficiently use the network in a situation where the macro cell 700 by the macro base station and the small cell 750 by the small base station are mixed together, The load on the network can be controlled by offloading the traffic to the small cell 750 according to the load condition of the network 700, thereby increasing the efficiency. In addition, different types of QoS traffic processing can be handled using differences in the connection status of the macro cell 700 and the small cell 750. [ Research on dual connectivity is under way so that traffic can be transmitted and received by simultaneously connecting to the macro cell 700 and the small cell 750 on the side of the terminal.

Hereinafter, a method for generating a reduced uplink DM-RS sequence will be described in an embodiment of the present invention.

A reduced uplink DM-RS sequence according to an embodiment of the present invention may include a first reduced uplink DM-RS sequence and a second reduced uplink DM-RS sequence.

For example, the first reduced uplink DM-RS sequence of the reduced uplink DM-RS sequence to be disclosed in FIG. 8 and FIG. 9 may be a resource block (s) of an even slot (first slot in one subframe) May be mapped to even-numbered subcarriers or odd-numbered subcarriers in one symbol. Also, the second reduced uplink DM-RS sequence may be mapped to a first reduced uplink DM-RS sequence in one symbol constituting the resource block (s) of the odd slot (second slot in one subframe) And can be mapped to subcarriers having the same subcarrier index as that of the subcarriers. The default DM-RS sequence may be a sequence generated based on the method published in FIGS. 4 to 6 and mapped to the resource block (s).

The first reduced uplink DM-RS sequence and the second reduced uplink DM-RS sequence may be orthogonal sequences (e.g., orthogonal sequences) for the first reduced reference signal sequence and the second reduced reference signal sequence, OCC) (hereinafter referred to as &quot; OCC &quot;). Hereinafter, in an embodiment of the present invention, the reference signal sequence indicates a sequence of a DM-RS for an uplink before OCC is applied, and an uplink DM-RS sequence indicates a sequence of an uplink after OCC is applied to a reference signal sequence. It is used as a term to indicate the sequence of DM-RS.

In the method for generating a reduced uplink DM-RS sequence according to an embodiment of the present invention, regardless of whether the number of resource blocks (s) allocated for the uplink DM-RS sequence is an even number or an odd number, It is possible to guarantee the orthogonality of the reduced uplink DM-RS transmitted between the layers when the uplink DM-RS is transmitted to a plurality of layers.

Hereinafter, a reduced uplink DM-RS mapping method and a reduced uplink DM-RS generating method according to an embodiment of the present invention will be specifically described with reference to FIGS. 8 to 11. FIG. The reduced uplink DM-RS mapping method and generation method disclosed in FIGS. 8 to 11 is one example of the other various reduced uplink DM-RS mapping methods that are compared with the default DM-RS sequence and mapped to few resources Can be used.

8 is a conceptual diagram illustrating a method of mapping a reduced uplink DM-RS sequence according to an embodiment of the present invention.

8 illustrates a method for mapping a first reduced uplink DM-RS sequence 810 and a second reduced uplink DM-RS 820 in a resource block (s) for each slot included in a subframe Post. The reference signal sequence for generating the first reduced uplink DM-RS sequence 810 and the second reduced uplink DM-RS sequence 820 may be defined as a reduced reference signal sequence and used. A method for generating a reduced reference signal sequence for generating a first reduced uplink DM-RS sequence 810 and a second reduced uplink DM-RS sequence 820 will be described later.

8 shows a normal CP subframe defined by a single carrier-frequency division multiple access (SC-FDMA) symbol including a normal cyclic prefix (CP). One resource block (RB) of the normal CP subframe includes seven consecutive SC-FDMA symbols (l = 0 to 6) in the time domain and 12 subcarriers (k '= 0 ~ 11). The index of the SC-FDMA symbol may increase sequentially as the time increases. The index of the subcarriers constituting the resource block can be sequentially increased in the direction of increasing frequency. Referring to the upper part of FIG. 8, the location to which the first reduced uplink DM-RS sequence 810 is mapped in the time domain may be preceded in time in an even slot (first slot in one subframe) (L = 3), which is the fourth SC-FDMA symbol. That is, the first reduced uplink DM-RS sequence 810 in the time domain is allocated to a position where the index of the SC-FDMA symbol is l = 3 in the even slot (first slot in one subframe) of the normal CP subframe Lt; / RTI &gt;

The first reduced uplink DM-RS sequence 810 in the frequency domain may be mapped to some subcarriers of 12 subcarriers (subcarriers # 0 to # 12, k '= 0 to 11). For example, the first reduced uplink DM-RS sequence 810 may be mapped to subcarriers corresponding to even indexes (k '= 0, 2, 4, 6, 8, 10).

The second reduced uplink DM-RS sequence 820 in the time domain is a 4 th SC-FDMA symbol (l = 1, 2, 3, 4, 3). &Lt; / RTI &gt; In other words, the second reduced uplink DM-RS sequence 820 in the time domain is located at the position where the index of the SC-FDMA symbol is l = 3 in the odd number slot (second slot in one subframe) of the normal CP subframe Lt; / RTI &gt;

The second reduced uplink DM-RS sequence 820 in the frequency domain includes a first reduced uplink DM-RS sequence of 12 subcarriers (subcarriers # 0 to # 12, k '= 0 to 11) Carriers of the same index as the subcarriers to which the subcarrier 810 is mapped. For example, the second reduced uplink DM-RS sequence 820 may be mapped to subcarriers corresponding to even indexes (k '= 0, 2, 4, 6, 8, 10).

That is, the first reduced uplink DM-RS sequence 810 is located at l = 3 in the even slot (the first slot in one subframe) of the normal CP subframe in the time domain, It can be mapped to the position of the index. Also, the second reduced uplink DM-RS sequence 820 is located at a position of l = 3 in an odd slot (the second slot in one subframe) of the normal CP subframe in the time domain, an even subcarrier It can be mapped to the position of the index.

In other words, the first reduced uplink DM-RS sequence 810 is a sequence of subcarriers sequentially increasing in the SC-FDMA symbols of l = 3 in an even slot (first slot in one subframe) The index of the subcarrier may be even. In addition, the second reduced uplink DM-RS sequence 820 is mapped in order of sequentially increasing indexes of subcarriers in an SC-FDMA symbol with l = 3 of an odd slot, and the index of a subcarrier may be even .

A subcarrier having an even index can be represented by a subcarrier having a subcarrier index satisfying mod2 = 0 in another expression (subcarrier index). By using the reduced uplink DM-RS sequence mapping method according to the embodiment of the present invention, compared to the case of transmitting the existing default uplink DM-RS, it is possible to use different uplink DM-RS resources, The applied reduced uplink DM-RS sequence may be mapped.

8 shows an extended CP subframe defined by an SC-FDMA symbol including an extended cyclic prefix (CP). One resource block of the extended CP subframe may be defined as six consecutive SC-FDMA symbols (l = 0 to 5) in the time domain and 12 subcarriers (k '= 0 to 11) continuous in the frequency domain have.

Referring to the lower part of FIG. 8, the position to which the first reduced uplink DM-RS sequence 810 is mapped in the time domain is pre-coded in an even time slot (first slot in one subframe) (L = 2), which is the third SC-FDMA symbol. That is, the first reduced uplink DM-RS sequence 810 in the time domain is located at the position where the index of the SC-FDMA symbol is l = 2 in an even slot (first slot in one subframe) of the extended CP subframe Lt; / RTI &gt;

The first reduced uplink DM-RS sequence 810 in the frequency domain may be mapped to some subcarriers of 12 subcarriers (subcarriers # 0 to # 12, k '= 0 to 11). For example, the first reduced uplink DM-RS sequence 810 may be mapped to subcarriers corresponding to even indexes (k '= 0, 2, 4, 6, 8, 10).

Also, the second reduced uplink DM-RS sequence 820 in the time domain is a third SC-FDMA symbol (l = 1, 2, ..., 2). &Lt; / RTI &gt; That is, the second reduced uplink DM-RS sequence 820 in the time domain is located at the position where the index of the SC-FDMA symbol is l = 2 in the odd slot (second slot in one subframe) of the extended CP subframe Lt; / RTI &gt;

The second reduced uplink DM-RS sequence 820 in the frequency domain includes a first reduced uplink DM-RS sequence of 12 subcarriers (subcarriers # 0 to # 12, k '= 0 to 11) Carriers of the same index as the subcarriers to which the subcarrier 810 is mapped. For example, the second reduced uplink DM-RS sequence 820 may be mapped to subcarriers corresponding to even indexes (k '= 0, 2, 4, 6, 8, 10).

That is, the first reduced uplink DM-RS sequence 810 is located at l = 2 in an even slot (the first slot in one subframe) of the extended CP subframe in the time domain, an even subcarrier It can be mapped to the position of the index. Also, the second reduced uplink DM-RS sequence 820 is located at l = 2 in the odd-numbered slot (the second slot in one subframe) of the extended CP subframe in the time domain, It can be mapped to the position of the index.

In other words, the first reduced uplink DM-RS sequence 810 is a sequence of subcarriers sequentially increasing in the SC-FDMA symbol with l = 2 in an even slot (first slot in one subframe) The index of the subcarrier may be even. The second reduced uplink DM-RS sequence 820 is mapped in the order of increasing subcarrier indices sequentially in SC-FDMA symbols of l = 2 in an even slot (first slot in one subframe) , And the index of the subcarrier may be an even number.

The first reduced uplink DM-RS sequence 810 and the second reduced uplink DM-RS sequence 820 are mapped to even-numbered subcarriers as an example. The first reduced uplink DM-RS sequence 810 and the second reduced uplink DM- And the second reduced uplink DM-RS sequence may be mapped to odd-numbered subcarriers.

9 is a conceptual diagram illustrating a method of mapping an uplink DM-RS sequence according to an embodiment of the present invention.

9, a method for mapping the first reduced uplink DM-RS sequence 910 and the second reduced uplink DM-RS sequence 920 to odd-numbered subcarriers, as in FIG. 8, is posted.

The upper part of FIG. 9 posts about how the first reduced uplink DM-RS sequence 910 and the second reduced uplink DM-RS sequence 920 are mapped in the normal CP sub-frame.

9, the first reduced uplink DM-RS sequence 910 is a sequence of subcarriers sequentially in an SC-FDMA symbol with l = 3 in an even slot (first slot in one subframe) The index of the subcarrier may be an odd number. Also, the second reduced uplink DM-RS sequence 920 is mapped in order of sequentially increasing indexes of subcarriers in an SC-FDMA symbol of l = 3 in an odd slot (a second slot in one subframe) , And the index of the subcarrier may be an odd number.

A subcarrier having an odd index can be represented by a subcarrier having a subcarrier index satisfying mod2 = 1 in another expression (subcarrier index).

The lower part of FIG. 9 posts about how the first reduced uplink DM-RS sequence 910 and the second reduced uplink DM-RS sequence 920 are mapped in the extended CP subframe.

9, the first reduced uplink DM-RS sequence 910 is a sequence of subcarriers sequentially in an SC-FDMA symbol with l = 2 in an even slot (first slot in one subframe) The index of the subcarrier may be an odd number. Also, the second reduced uplink DM-RS sequence 820 is mapped in order of increasing index of subcarriers sequentially in SC-FDMA symbols of l = 2 in an odd slot (second slot in one subframe) , And the index of the subcarrier may be an odd number.

Hereinafter, in an embodiment of the present invention, a method for generating the reduced uplink DM-RS (the first reduced uplink DM-RS sequence and the second reduced DM-RS sequence) disclosed in FIGS. 8 and 9 is posted . The first reduced uplink DM-RS sequence and the second reduced uplink DM-RS sequence may be generated based on Equation (7) below.

Here, the first reduced uplink DM-RS sequence is mapped to subcarriers corresponding to even indexes (k '= 0, 2, 4, 6, 8, 10) in one resource block in the frequency domain, (K '= 1, 3, 5, 7, 9, 11) within one resource block in the frequency domain is assumed to be mapped to a subcarrier do.

&Quot; (7) &quot;

Referring to Equation (7), unlike Equation (2)

Can be reduced by half. In other words,

And may correspond to half of the number of subcarriers allocated to the PUSCH.

The length of the reference signal sequence may be expressed by the number of subcarriers allocated for the reference signal sequence as described above. Thus, according to an embodiment of the present invention

May be the number of subcarriers used to map the first reduced uplink DM-RS sequence or the second reduced uplink DM-RS sequence on the frequency domain.

That is, in the reduced uplink DM-RS sequence mapping method according to an embodiment of the present invention, a first reduced uplink signal sequence is generated based on a reduced reference signal sequence having a length 1/2 shorter than the length of a conventional reference signal sequence, Link DM-RS sequence and a second reduced uplink DM-RS sequence. The first reduced uplink DM-RS sequence and the second reduced uplink DM-RS sequence are added to the reduced reference signal sequence as OCC

Can be determined. For example, in the reduced reference signal sequence, the first sequence value of the OCC

To determine a first reduced uplink DM-RS sequence, and in a reduced reference signal sequence, a second sequence value of the OCC

May be applied to determine the second reduced uplink DM-RS sequence.

The reduced reference signal sequence may be generated based on Equation (8) below.

&Quot; (8) &quot;

Referring to equation (8), the reduced reference signal sequence is

(M) of the resource block (s) to which the number of subcarriers used for the uplink DM-RS reduced by the number of subcarriers in one resource block

), Which is a value obtained by multiplying a value obtained by multiplying the product by the product Also, the base sequence used to generate the reduced reference signal sequence (

) May also have a reduced sequence length.

Basic sequence (

(Physical cell ID or virtual cell ID) in the case of u and v, which are parameters required for generation of the virtual cell ID, may have different values. That is, if the slot or cell ID is different, the basic sequence may be different. A first reduced uplink DM-RS sequence and a second reduced uplink DM-RS sequence according to an embodiment of the present invention may be mapped in one symbol of different slots. That is, the first reduced uplink DM-RS sequence and the second reduced uplink DM-RS sequence may be generated based on different first reduced reference signal sequences and second reduced reference signal sequences.

Also, according to an embodiment of the present invention, a cyclic shift (cs) value per layer multiplied by a reference signal sequence

Can be determined as Equation (9) below.

&Quot; (9) &quot;

When the number m of resource block (s) allocated to map the reduced uplink DM-RS sequence is an even number as described above, the sequence generation method and the CS / OCC generation / Mapping method can be used as it is. However, if the number m of resource block (s) allocated to map the reduced uplink DM-RS sequence is an odd number, only an even-numbered sub-carrier or odd-numbered sub- , The number of subcarriers to which the reduced uplink DM-RS sequence is mapped may not be a multiple of 12. That is, the length of the reduced uplink DM-RS sequence may not be a multiple of 12. Therefore, when applying the cyclic shift and / or OCC that was previously used to determine the default uplink DM-RS sequence, the orthogonality between the sequences may be compromised.

In order to solve this problem, in the embodiment of the present invention, when the reduced uplink DM-RS sequence is mapped to the resource block (s), it is reduced to prevent the orthogonality of the reduced uplink DM- A cyclic shift (cs) value per layer multiplied by the reference signal sequence

Can be determined as shown in Equation (10) below.

&Quot; (10) &quot;

Referring to Equation (10), different equations may be used depending on whether the number of resource block (s) allocated to transmit the first reduced uplink DM-RS sequence or the second reduced uplink DM-RS sequence is an even number The value of the layer-by-layer cyclic shift can be determined. For example, if the number of resource block (s) allocated to be mapped to the first reduced uplink DM-RS sequence or the second reduced uplink DM-RS sequence is even (m mod2 = 0)

The value of the cyclic shift can be determined. On the contrary, when the number of resource blocks (s) allocated to be mapped to the first reduced uplink DM-RS sequence or the second reduced uplink DM-RS sequence is odd (m mod2 = 1)

The value of the cyclic shift can be determined.

If the number m of RBs to which the first reduced uplink DM-RS sequence or the second reduced uplink DM-RS sequence is mapped is mapped to six subcarriers for each resource block, The number of subcarriers to which the uplink DM-RS sequence or the second reduced uplink DM-RS sequence is mapped may be a multiple of 12. [ That is, the length of the reduced uplink DM-RS sequence is divided by 12. However, even when the number m of allocated resource block (s) is odd, the first reduced uplink DM-RS sequence or the second reduced uplink DM-RS sequence is mapped to six subcarriers in each resource block The number of mapped subcarriers may be a multiple of six.

That is, in Equation (10), orthogonality between the reduced uplink DM-RS sequences can be guaranteed by determining the phase of the cyclic shift to be used in the sequence differently according to the length of the generated uplink DM-RS sequence generated.

According to another embodiment of the present invention, only when the number m of allocated resource block (s) for the reduced uplink DM-RS sequence is even, the first reduced uplink DM-RS sequence Or to use a second reduced uplink DM-RS sequence. In this case, only when the number m of RBs allocated for the reduced uplink DM-RS sequence is an even number, only the first reduced uplink DM-RS sequence or the second reduced uplink DM- Sequence may be used. In this case

The value of the cyclic shift can be determined.

Even if the orthogonality of the reduced uplink DM-RS sequence is preserved in the same manner as in Equation (10), if a reduced uplink DM-RS sequence generated based on Table 1 is generated and transmitted in a plurality of layers, Can be damaged. An embodiment of the present invention discloses a method that does not compromise the orthogonality of a reduced uplink DM-RS sequence transmitted in a plurality of layers.

8 and 9 illustrate an example of a reduced uplink DM-RS. In addition, the reduced uplink DM-RS may be mapped to the resource block (s) in the same manner as in FIGS. 10 and 11. FIG.

Hereinafter, the reduced uplink DM-RS sequence disclosed in FIG. 10 and FIG. 11 is mapped to a first reduced uplink DM-RS sequence mapped to even-numbered subcarriers in one symbol and to odd-numbered subcarriers And a second reduced uplink DM-RS sequence to be transmitted. The first reduced uplink DM-RS sequence and the second reduced uplink DM-RS sequence may be a sequence generated by applying OCC to the first reduced reference signal sequence and the second reduced reference signal sequence. Hereinafter, in an embodiment of the present invention, the reference signal sequence indicates a sequence of a DM-RS for an uplink before OCC is applied, and an uplink DM-RS sequence indicates a sequence of an uplink after OCC is applied to a reference signal sequence. It is used as a term to indicate the sequence of DM-RS.

8 and 9, a first reduced reference signal sequence for generating a first reduced uplink DM-RS sequence and a second reduced uplink DM-RS sequence disclosed in FIGS. 10 and 11, and a second reduced reference signal sequence for generating a second reduced uplink DM- 2 The reduced candidate signal sequence may be the same sequence.

8 and 9, the amount of resources used for transmitting the uplink DM-RS can be reduced by using the reduced uplink DM-RS sequence mapping method as shown in FIG. 10 and FIG. In addition, although the amount of resources used to transmit the uplink DM-RS is reduced, orthogonality between sequences can be guaranteed by applying OCC to each reference signal sequence.

In addition, when using the reduced uplink DM-RS sequence mapping method disclosed in FIGS. 10 and 11, a first reduced uplink DM-RS sequence mapping method, in which OCC is applied on the same symbol in one slot unlike FIGS. 8 and 9, By using the RS and the second reduced uplink DM-RS, a reduced uplink DM-RS with OCC can be used without disabling group hopping and sequence hopping.

Hereinafter, the embodiment of the present invention specifically posts the reduced uplink DM-RS sequence.

10 is a conceptual diagram illustrating a method of mapping an uplink DM-RS sequence according to an embodiment of the present invention.

FIG. 10 illustrates a method for mapping a first reduced uplink DM-RS sequence 1010 and a second reduced uplink DM-RS 1020 in a subframe. As described above, the reference signal sequence for generating the first reduced uplink DM-RS sequence 1010 and the second reduced uplink DM-RS sequence 1020 may be the same sequence. A method for generating a reference signal sequence for generating the first reduced uplink DM-RS sequence 1010 and the second reduced uplink DM-RS sequence 1020 will be described later.

The upper part of FIG. 10 shows a normal CP subframe defined by an SC-FDMA symbol including a normal CP. One resource block of a normal CP subframe can be defined as 7 consecutive SC-FDMA symbols (l = 0 to 6) in the time domain and 12 subcarriers (k '= 0 to 11) continuous in the frequency domain have. The index of the SC-FDMA symbol may increase sequentially as the time increases. The index of the subcarrier can be sequentially increased in the direction of increasing frequency.

10, the locations to which the first reduced uplink DM-RS sequence 1010 and the second reduced uplink DM-RS sequence 1020 are mapped in the time domain are the even-numbered slots of the normal CP sub- (L = 3) preceding a time in the first slot (one slot in one subframe). That is, the first reduced uplink DM-RS sequence 1010 and the second reduced uplink DM-RS sequence 1020 in the time domain are even slots (the first slot in one subframe) of the normal CP subframe, The index of the SC-FDMA symbol may be mapped to a position of l = 3.

The first reduced uplink DM-RS sequence 1010 and the second reduced uplink DM-RS sequence 1020 in the frequency domain are divided into 12 subcarriers (subcarriers # 0 through # 11, k '= 0 To 11 and the remaining subcarriers, respectively. For example, the first reduced uplink DM-RS sequence 1010 is mapped to a specific subcarrier, and the second reduced uplink DM-RS sequence 1020 is mapped to a subcarrier Can be mapped to subcarriers.

For example, the first reduced uplink DM-RS sequence 1010 may be mapped to subcarriers of an even index (k '= 0, 2, 4, 6, 8, 10) The uplink DM-RS sequence 1020 may be mapped to subcarriers of odd indexes (k '= 1, 3, 5, 7, 9, 11). That is, the first reduced uplink DM-RS sequence 1010 is located at l = 3 in the even slot (the first slot in one subframe) of the normal CP subframe in the time domain, It can be mapped to the position of the index. Also, the second uplink DM-RS sequence 1020 is located at a position of l = 3 in the even slot (the first slot in one subframe) of the normal CP subframe in the time domain, the position of the odd subcarrier index Location. &Lt; / RTI &gt;

In other words, the first reduced uplink DM-RS sequence 1010 is mapped in order of decreasing subcarrier index sequentially in the SC-FDMA symbol with l = 3, and the index of the subcarrier may be even. Also, the second reduced uplink DM-RS sequence 1020 is mapped in order of sequentially increasing indexes of subcarriers in the SC-FDMA symbol with l = 3, and the index of the subcarriers may be odd.

A subcarrier having an even index can be represented by a subcarrier having a subcarrier index satisfying mod2 = 0 in another expression (subcarrier index). Similarly, a subcarrier having an odd index can be represented by a subcarrier having a subcarrier index satisfying mod2 = 1 in another expression (subcarrier index).

By using the reduced uplink DM-RS sequence mapping method as shown in FIGS. 10 and 11, a reduced uplink DM-RS sequence applying different OCCs in one symbol can be mapped. The reduced uplink DM-RS sequence applying different OCCs in one symbol is more effective for UEs moving with high mobility in a frequency-selective fading channel of a small cell Lt; / RTI &gt; For a UE with high mobility, a reduced uplink DM-RS sequence applying OCC between adjacent subcarriers rather than an uplink DM-RS sequence applying OCC between slots can have higher reliability in terms of orthogonality.

The lower part of FIG. 10 shows an extended CP subframe defined by an SC-FDMA symbol including an extended CP. One resource block of the extended CP subframe may be defined as six consecutive SC-FDMA symbols (l = 0 to 5) in the time domain and 12 subcarriers (k '= 0 to 11) continuous in the frequency domain have.

10, the positions where the first reduced uplink DM-RS sequence 1010 and the second reduced uplink DM-RS sequence 1020 are mapped in the time domain are the even slots of the extended CP subframe (L = 2) preceding a time in the first slot (one slot in one subframe). That is, the first reduced uplink DM-RS sequence 1010 and the second reduced uplink DM-RS sequence 1020 in the time domain are allocated to even slots (first slot in one subframe) Lt; RTI ID = 0.0 &gt; l = 2 &lt; / RTI &gt;

On the frequency domain, the extended CP subframe may be mapped to the first reduced uplink DM-RS 1010 and the second reduced uplink DM-RS 1020, similar to the normal CP subframe. That is, in the extended CP subframe, the first reduced uplink DM-RS sequence 1010 is mapped in order of increasing index of subcarriers sequentially in SC-FDMA symbols of l = 2, and the index of subcarriers is mapped to even Lt; / RTI &gt; Also, the second reduced uplink DM-RS sequence 1020 is mapped in order of sequentially increasing indexes of subcarriers in the SC-FDMA symbol with l = 2, and the index of the subcarriers may be an odd number. That the index of the subcarrier is an even number can indicate a subcarrier index satisfying (subcarrier index) mod2 = 0. In addition, when the index of the subcarrier is an odd number, it can indicate a subcarrier index satisfying (subcarrier index) mod2 = 1.

In FIG. 10, a first reduced uplink DM-RS (first slot in one subframe) mapped to an even slot (first slot in one subframe) and an even slot Sequence 1010 and the second reduced uplink DM-RS sequence 1020. [0064] According to an embodiment of the present invention, an odd-numbered slot (a second slot in one subframe) and an odd-numbered slot (a second slot in one subframe) of a normal CP subframe other than an even- The reduced uplink DM-RS sequence 1010 and the second reduced uplink DM-RS sequence 1020 may be mapped.

11 is a conceptual diagram illustrating a method of mapping an uplink DM-RS sequence according to an embodiment of the present invention.

In FIG. 11, the first reduced uplink DM-RS sequence (the first one in one subframe) and the second reduced uplink DM-RS sequence (the second one in one subframe) in the normal CP subframe 1110 and the second reduced uplink DM-RS 1120 are mapped.

The upper part of FIG. 11 shows a first reduced uplink DM-RS sequence 1110 and a second reduced uplink DM-RS 1120 in an odd slot (a second slot in one subframe) of the normal CP subframe Is mapped.

In the frequency domain, mapping can be performed in the same manner as described above with reference to FIG. The positions at which the first reduced uplink DM-RS sequence 1110 and the second reduced uplink DM-RS sequence 1120 are mapped in the time domain are odd-numbered slots of the normal CP subframe (the second Slot) preceding a time slot in the first SC-FDMA symbol (l = 3).

The lower part of FIG. 11 shows a first reduced uplink DM-RS sequence 1110 and a second reduced uplink DM-RS 1120 in an odd number slot (a second slot in one subframe) of the extended CP subframe Is mapped.

In the frequency domain, mapping can be performed in the same manner as described above with reference to FIG. The location to which the first reduced uplink DM-RS sequence 1110 and the second reduced uplink DM-RS sequence 1120 are mapped in the time domain is an odd-numbered slot of the extended CP subframe (the second Slot) preceding the time slot in the first SC-FDMA symbol (l = 2).

The method for generating the first reduced uplink DM-RS sequence and the second reduced uplink DM-RS sequence disclosed in FIGS. 10 and 11 will be described with reference to FIGS. 8 and 9, (A first reduced uplink DM-RS sequence and a second reduced DM-RS sequence). That is, the first reduced uplink DM-RS sequence and the second reduced uplink DM-RS sequence disclosed in FIGS. 10 and 11 may be generated based on Equations (7) to (10) as described above .

Therefore, as in the case of the reduced uplink DM-RS disclosed in FIGS. 8 and 9, when the number of the allocated resource block (s) allocated to the reduced uplink DM-RS disclosed in FIGS. 10 and 11 is odd The orthogonality of the reduced uplink DM-RS may be impaired. Therefore, when the number of resource block (s) allocated to the reduced uplink DM-RS is odd, the value of the cyclic shift can be determined based on Equation (10).

In the reduced uplink DM-RS sequence mapping method disclosed in FIGS. 10 and 11, as in the reduced uplink DM-RS sequence mapping method disclosed in FIGS. 8 and 9, Even if the orthogonality of the DM-RS sequence is preserved, if a reduced uplink DM-RS sequence generated based on Table 1 is generated and transmitted in a plurality of layers, the orthogonality between the reduced uplink DM-RS sequences is impaired . Hereinafter, an embodiment of the present invention discloses a method of not reducing the orthogonality between reduced uplink DM-RS sequences transmitted in a plurality of layers.

The OCC applied to each layer can be determined according to Table 1. Each layer can determine a first reduced uplink DM-RS sequence and a second reduced uplink DM-RS to be transmitted in each layer based on Equation (7).

When Table 1 is used to apply OCC to each of the plurality of layers, a cyclic shift (cs) value determined based on Equation (10) according to an embodiment of the present invention

RS-based DM-RS sequences, it may occur that the reduced DM-RS sequences can not be distinguished between the reduced uplink DM-RS sequences.

More specifically, when the number m of resource block (s) allocated to the reduced uplink DM-RS sequence is an even number,

Can be used to determine the cyclic shift. If the number (m) of resource block (s) allocated to the reduced uplink DM-RS sequence is an odd number,

Can be used to determine the cyclic shift. If the number m of resource block (s) allocated to the reduced uplink DM-RS sequence is an even number, it is the same as in the conventional case, but the resource blocks allocated to the reduced uplink DM- (M) is an odd number, the first layer

) And the second layer (

May not be distinguished from the uplink DM-RS sequence mapped to the uplink DM-RS sequence.

Specifically, as shown in Table 1, by the value of the CS field for the uplink DM-RS sequence of the DCI format associated with the most recent uplink,

Can be determined.

(For example, when the cyclic shift field is '000', the first layer has a value of 0 and the second layer has a value of 6). Difference of 6

Value is determined as the input value

The cyclic shift determined based on the value of the first layer and the second layer may be the same value. Specifically, Equation (6) for determining the value of the cyclic shift

Is used to determine the value of the cyclic shift,

If the value of &lt; RTI ID = 0.0 &gt;

(I.e., the origin). Therefore,

Values have the same cyclic shift value. Also, the same OCC [1,1] is applied to the first layer and the second layer, so that a downlink DM-RS sequence that is reduced between the first layer and the second layer is not distinguished.

Therefore, when the number m of the resource block (s) to which the downlink reduced downlink DM-RS sequence is mapped on the frequency axis is an odd number as shown in FIGS. 8 to 11, Can not be distinguished. Therefore, each terminal can only transmit the reduced uplink DM-RS in only one layer.

Hereinafter, in an embodiment of the present invention, when the number of resource block (s) mapped to the reduced uplink DM-RS sequence is an odd number, the value of cyclic shift and / or the value of OCC are set differently, Or methods for ensuring orthogonality between terminals. By using this method, it is possible to transmit an uplink DM-RS sequence ensuring orthogonality in a plurality of layers.

Table 6 below shows a first method for ensuring orthogonality between layers and / or terminals according to an embodiment of the present invention.

<Table 6>

Referring to Table 6, the value of the OCC for each layer

Shall remain the same as in Table 1. However, compared to Table 1,

The orthogonality between the layers can be guaranteed. Hereinafter, in the embodiment of the present invention

Is defined and used as a DC-based CS decision value.

Table 6 shows the existing second layer (Table 1) published in Table 1

) And the third layer (

) Were exchanged with each other.

In the case of using a single user (SU) -MIMO (multiple input multiple output) as a transmission method in Table 6, the value of the cyclic shift and / or the OCC is changed until the number of layers is four The orthogonality between the uplink DM-RS sequences can be guaranteed.

Also, when Table 6 is used, when MU (multi user) -MIMO is used as the transmission method, orthogonality can be guaranteed with the value of the cyclic shift and the OCC until the total number of layers is four. In the MU-MIMO environment, the total number of layers may mean the sum of the number of layers for each terminal.

The division of these four layers may be possible only in the cyclic shift field of some of the cyclic shift fields of Table 6. [ Also in Table 6, in the case of some cyclic shift fields, the uplink DM-RS sequence can not be distinguished. This will be specifically described in Fig.

12 is a conceptual diagram illustrating a method for ensuring orthogonality between layers and / or terminals according to an embodiment of the present invention.

12 shows the cyclic shift and OCC for ensuring orthogonality between the layers and / or the terminals published in Table 6. FIG.

If the value of the cyclic shift field is indicated as '000', '001', '010' or '111' in Table 6, uplink DM-RS sequence orthogonality can be guaranteed up to four layers.

Referring to FIG. 11, assuming that the value of the cyclic shift field is '000', the DCI-based CS decision value may have 0, 3, 6, and 9. If the DCI-based CS decision values are 0 and 3, there is a cyclic shift value between CS decision values 0 and 3

The two uplink DM-RS sequences can be distinguished even if the OCC is equal to [1,1]. Even when the DCI-based CS decision values are 6 and 9, the values of the cyclic shifts between the CS decision values 6 and 9

The uplink DM-RS sequence can be distinguished. However, in the case of DCI-based CS decision values 0 and 6 or 3 and 9, since the values of the cyclic shifts are different by 0 between CS decision values 0 and 6 and CS decision values 3 and 9, It can not be distinguished by value alone. In this case, it is possible to distinguish the uplink DM-RS sequence by using [1, -1] in case of 6 and 9, as opposed to using [1, 1] have.

If the value of the cyclic shift field is '011', '100', '101', or '110' in Table 6, orthogonality can be guaranteed up to two layers. That is, only the uplink DM-RS sequence of the first layer and the second layer can be distinguished.

Referring to FIG. 12, assuming that the value of the cyclic shift field is '011', the DCI-based CS decision value may have 4, 7, 10, 1. If the DCI-based CS decision values are 4 and 7, the value of the cyclic shift is between CS decision values 4 and 7

The two uplink DM-RS sequences can be distinguished even if the OCC is equal to [1,1]. Even if the DCI-based CS decision values are 10 and 1, the values of the cyclic shifts between the CS decision values 10 and 1

The uplink DM-RS sequence can be distinguished. However, when the DCI-based CS decision values are 4 and 10 or 7 and 1, the value of the cyclic shift is different by 0 between the CS decision values 4 and 10 and between the CS decision values 7 and 1, It can not be distinguished by value alone. However, even if DCI-based CS decision values are 10 and 1, the values of OCC are the same as those of DCI-based CS decision values 4 and 7, respectively. Therefore, the uplink DM-RS sequence of the first layer and the second layer can not be distinguished from the third layer and the fourth layer and the uplink DM-RS sequence. Therefore, when the value of the cyclic shift field is '011', it is possible to use an uplink DM-RS sequence distinguished only for two layers.

Table 7 below shows a second method for ensuring orthogonality between layers and / or terminals according to an embodiment of the present invention.

<Table 7>

Referring to Table 7, for each layer

(CS decision value based on DCI) is the same as in Table 1, and the value of the OCC for each layer

To ensure orthogonality between the layers.

In Table 7, in order to guarantee the orthogonality between the layers, the existing second layer (

) And the third layer (

) Were exchanged with each other.

When SU-MIMO is used as the transmission method, the orthogonality between the uplink DM-RS sequences can be guaranteed based on the value of the cyclic shift and / or the OCC until the number of layers is four, as in the conventional case.

When MU-MIMO is used as the transmission method, it is possible to ensure the orthogonality with the value of the cyclic shift and / or the OCC until the total number of layers is four. In the MU-MIMO environment, the total number of layers may mean the sum of the number of layers for each terminal.

The division of these four layers may be possible only in some of the cyclic shift fields in Table 7. [ Also in Table 7, a combination of some cyclic shifts and OCCs can not distinguish the uplink DM-RS sequence. This is described in Fig.

13 is a conceptual diagram illustrating a method for ensuring orthogonality between layers and / or terminals according to an embodiment of the present invention.

FIG. 13 shows a cyclic shift and OCC for ensuring orthogonality between inter-layer and / or inter-terminal as disclosed in Table 7. FIG.

If the value of the cyclic shift field is '000', '001', '010' or '111' in Table 7, orthogonality of up to four layers can be guaranteed.

Referring to FIG. 13, assuming that the value of the cyclic shift field is '000', the DCI-based CS decision value may have 0, 6, 3, and 9. When the DC-based CS decision values are 0 and 6, there is no difference in the cyclic shift value between the CS decision values 0 and 6. However, since the OCCs have different [1,1], [1, -1] Link DM-RS sequences can be distinguished. Similarly, even when the DCI-based CS decision values are 3 and 9, there is no difference in the cyclic shift values between the CS decision values 3 and 9, but since the OCCs have different [1,1] and [1, -1] RTI ID = 0.0 &gt; DM-RS &lt; / RTI &gt;

If the value of the cyclic shift field is '011', '100', '101', or '110' in Table 7, orthogonality can be guaranteed up to one layer. That is, it is impossible to distinguish only the uplink DM-RS sequence for a plurality of layers.

Referring to FIG. 13, assuming that the value of the cyclic shift field is '011', the DCI-based CS decision value may have 4, 10, 7, 1. If the DCI-based CS decision values are 4 and 10, there is no difference in the cyclic shift between CS decision values 4 and 10, and the OCC is equal to [1,1]. That is, the uplink DM-RS sequence of the first layer and the second layer can not be distinguished. Therefore, only the uplink DM-RS sequence in the first layer can be used.

Table 8 below shows a third method for ensuring orthogonality between layers and / or terminals according to an embodiment of the present invention.

<Table 8>

Referring to Table 8, the value of the OCC for each layer

Are the same as in Table 1,

(CS value determined based on DCI) may be changed to ensure orthogonality between layers.

Table 8 sets DCI based decision values to ensure orthogonality at all layers using all cyclic shift fields. The second layer (

), The third layer

), The fourth layer (

) &Lt; / RTI &gt; DCI-based CSI decision value of the first layer (

) And the modular 12 modular operation are set to 3, 1, and 4, respectively.

Based CS decision value for the first layer, a second DCI-based CS decision value for the second layer, a third DCI-based CS decision value for the third layer, a second DCI-based CS decision value for the second layer, When dividing by the fourth DCI-based CS decision value, the DCI-based CS decision value of the table of Table 8 can be determined on the basis of the following operation.

The modulo 12 computed value of the difference between the second DCI-based CS decision value and the first DCI-based CS decision value may be three. The value obtained by modulo 12 calculation of the difference between the third DCI-based CS decision value and the first DCI-based CS decision value is 1, and the difference between the fourth DCI-based CS decision value and the first DCI- One value may be four.

When SU-MIMO is used as the transmission method, the orthogonality between uplink DM-RS sequences can be guaranteed based on the value of the cyclic shift and / or the OCC until the number of layers is four, as in the conventional case. In addition, when MU-MIMO is used as the transmission method, orthogonality can be guaranteed with the value of the cyclic shift and the OCC until the number of layers for each terminal is four.

FIG. 14 is a conceptual diagram illustrating a method for ensuring orthogonality between layers and / or terminals according to an embodiment of the present invention.

FIG. 14 shows a cyclic shift and OCC for ensuring orthogonality between inter-layer layers and / or terminals posted in Table 8.

In Table 8, it is possible to guarantee orthogonality with respect to values of all cyclic shift fields.

Referring to FIG. 14, assuming that the value of the cyclic shift field is '000', the DCI-based CS decision value may have 0, 3, 1, and 4. If DCI-based CS decision values are 0 and 3, there is a difference in cyclic shift value between CS decision values 0 and 3

The two uplink DM-RS sequences can be distinguished even if the OCC is equal to [1,1]. Even if the DC-based CS decision values are 1 and 4, there is a cyclic shift value between the CS decision values 1 and 4

The uplink DM-RS sequence can be distinguished. On the other hand, when DCI-based CS decision values are 0 and 1 or 3 and 4, there is not a large difference in cyclic shift values between CS decision values 0 and 1 and CS decision values 3 and 4. In this case, the value of OCC is set to 1 by using DCI-based CS decision values 0, 3, and by using [1, -1] -RS sequence can be distinguished.

Table 8 as well as various tables may be defined to ensure orthogonality between layers and / or terminals.

Table 9 is also a table for ensuring orthogonality among layers and / or terminals according to the embodiment of the present invention.

<Table 9>

Referring to Table 9, the second layer (

), The third layer (

), The fourth layer (

The DCI-based CS decision value of the first layer (

) And a modular operation (modular 12) with the DCI-based CSI decision value of the DCI-based CSI decision value, the difference can be set to 3, 2, and 4, respectively.

That is, the modulo 12 calculation of the difference between the second DCI-based CS decision value and the first DCI-based CS decision value may be three. The value obtained by modulo 12 calculation of the difference between the third DCI-based CS decision value and the first DCI-based CS decision value is 2, and the difference between the fourth DCI-based CS decision value and the first DCI- One value may be four.

Table 10 is also a table for ensuring orthogonality among layers and / or terminals according to the embodiment of the present invention.

<Table 10>

In Table 10, the second layer (

), The third layer (

), The fourth layer (

) &Lt; / RTI &gt; based on the DCI format &lt; RTI ID = 0.0 &gt;

) And the modular operation (modular 12), the difference can be set to 3, 1, and 5, respectively.

That is, the modulo 12 calculation of the difference between the second DCI-based CS decision value and the first DCI-based CS decision value may be three. The value obtained by modulo 12 calculation of the difference between the third DCI-based CS decision value and the first DCI-based CS decision value is 1, and the difference between the fourth DCI-based CS decision value and the first DCI- One value can be 5.

Table 11 is also a table for ensuring orthogonality between layers and / or terminals according to the embodiment of the present invention.

<Table 11>

In Table 11, the second layer (

), The third layer (

), The fourth layer (

) &Lt; / RTI &gt; is based on the first layer (

) And the modular operation (modular 12), the difference can be set to 3, 2, and 5, respectively.

The modulo 12 computed value of the difference between the second DCI-based CS decision value and the first DCI-based CS decision value may be three. The value obtained by modulo 12 calculation of the difference between the third DCI-based CS decision value and the first DCI-based CS decision value is 2, and the difference between the fourth DCI-based CS decision value and the first DCI- One value can be 5.

That is, referring to Tables 6 to 11, the DCI-based CS decision value and the OCC are used for a first primary uplink DM-RS sequence, a second primary uplink DM-RS sequence, a first secondary uplink DM- The second secondary uplink DM-RS sequences may be determined to be orthogonal to each other.

Wherein the first primary uplink DM-RS sequence is a first uplink DM-RS sequence for a first layer of a plurality of layers, a second primary uplink DM-RS sequence is for a first layer of a plurality of layers, And indicates a second uplink DM-RS sequence. Also, the first secondary uplink DM-RS sequence may include a first secondary uplink DM-RS sequence for the remaining layers of the plurality of layers, a second secondary uplink DM-RS sequence for the remaining layers of the plurality of layers, Link Indicates the DM-RS sequence.

More specifically, the DCI-based CS decision value includes a first cyclic shift value for generating a first primary uplink DM-RS sequence and a second primary uplink DM-RS sequence and a first cyclic shift value for generating a first secondary uplink DM- Sequence and a second cyclic shift value for generating a second secondary uplink DM-RS sequence

Lt; / RTI &gt; If the difference between the first cyclic shift value and the second cyclic shift value is

RS sequence, a first secondary uplink DM-RS sequence and a second secondary uplink DM-RS sequence for generating a first primary uplink DM-RS sequence and a second primary uplink DM-RS sequence, The second OCC for generating the -RS sequence can be determined to be assigned to different codes.

That is, the method for determining a reduced uplink DM-RS sequence according to an embodiment of the present invention includes receiving information on the number of resource blocks (s) allocated for a reduced uplink DM-RS sequence by the UE And the UE may map the reduced uplink DM-RS sequence to the allocated resource block (s).

If the number of allocated resource block (s) is an even number, the reduced uplink DM-RS sequence is generated based on the value of the first circular shift field received by the UE, Sequence and a second reduced uplink DM-RS sequence.

If the number of allocated resource block (s) is an odd number, the reduced uplink DM-RS sequence is a third reduced uplink DM-RS sequence based on the value of the first circular shift field received by the UE, And a fourth reduced uplink DM-RS sequence.

If the number of allocated resource block (s) is even, the value of the first cyclic shift field is used to generate the first reduced uplink DM-RS sequence and the second reduced uplink DM-RS sequence A cyclic shift (CS) determination value based on a downlink control field (DCI), and a first orthogonal sequence. The length of the first reduced uplink DM-RS sequence and the length of the second reduced uplink DM-RS sequence may each be a multiple of twelve.

Or if the number of allocated resource block (s) is odd, the value of the first cyclic shift field is used to generate the third reduced uplink DM-RS sequence and the fourth reduced uplink DM-RS sequence A second DCI-based CS decision value and a second orthogonal sequence. The length of the third reduced uplink DM-RS sequence and the length of the fourth reduced uplink DM-RS sequence may each be a multiple of six.

That is, even if the value of the same cyclic shift field is used, different DCI-based CS decision values and orthogonal sequences can be determined according to whether the number of allocated resource block (s) is even or not.

The first DCI-based CS decision value and the first orthogonal sequence are generated such that the remaining reduced uplink DM-RS sequence transmitted in the other layer and the first reduced uplink DM-RS sequence are orthogonal and the remaining reduced uplink DM- RS sequence and the second reduced uplink DM-RS sequence may be orthogonal.

The second DCI-based CS decision value and the second orthogonal sequence are orthogonalized between the remaining reduced uplink DM-RS sequence transmitted in the other layer and the third reduced uplink DM-RS sequence, and the remaining reduced uplink DM -RS sequence and the fourth reduced uplink DM-RS sequence may be orthogonalized.

15 is a block diagram illustrating a wireless communication system according to an embodiment of the present invention.

15, a base station 1500 includes a processor 1510, a memory 1520, and a radio frequency (RF) unit 1530. The memory 1520 is coupled to the processor 1510 and stores various information for driving the processor 1510. [ RF section 1520 is coupled to processor 1510 to receive and / or transmit a wireless signal and / or a wireless signal (e.g., a reduced uplink DM-RS published herein). The processor 1510 may receive the uplink DM-RS sequence published herein and demodulate the uplink data based on the received uplink DM-RS. The operation of the base station of the serving cell in the above-described embodiment may be implemented by the processor 1510. [

The wireless device (or terminal) 1550 includes a processor 1560, a memory 1570, and an RF section 1580. The memory 1570 is coupled to the processor 1560 to store various information for driving the processor 1560. RF section 1580 is coupled to processor 1560 to receive a radio signal or transmit a radio signal (e.g., a reduced uplink DM-RS sequence published herein). Processor 1560 implements the functions, processes and / or methods proposed in the embodiments of Figs. 8-14 of the present invention. The operation of the terminal in any of the embodiments disclosed herein may be implemented by the processor 1560. [

The processor may comprise an application-specific integrated circuit (ASIC), other chipset, logic circuitry and / or a data processing device. The memory may include read-only memory (ROM), random access memory (RAM), flash memory, memory cards, storage media, and / or other storage devices. The RF unit may include a baseband circuit for processing the radio signal. When the embodiment is implemented in software, the above-described techniques may be implemented with modules (processes, functions, and so on) that perform the functions described above. The module is stored in memory and can be executed by the processor. The memory may be internal or external to the processor and may be coupled to the processor by any of a variety of well known means.

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 not intended to limit the scope of the present invention but to limit the scope of the technical idea of the present invention. The scope of protection of the present invention should be construed according to the following claims, and all technical ideas within the scope of equivalents should be construed as falling within the scope of the present invention.

Claims (10)

In a reduced uplink DM (demodulation) -RS (reference signal) sequence determination method,
Receiving information on the number of resource blocks (s) allocated to the UE for the reduced uplink DM-RS sequence in one slot of a UL subframe; And
And determining, by the UE, an uplink DM-RS sequence to be mapped to the uplink sub-frame based on information on the number of the allocated resource block (s)
If the number of allocated resource block (s) is an even number, the reduced uplink DM-RS sequence includes a first reduced uplink DM-RS sequence generated based on a value of a first cyclic shift field and a second reduced uplink DM- A reduced uplink DM-RS sequence,
If the number of the allocated resource block (s) is an odd number, the reduced uplink DM-RS sequence includes a third reduced uplink DM-RS sequence generated based on the value of the first cyclic shift field, 4 reduced uplink DM-RS sequence,
If the number of the allocated resource block (s) is even, the value of the first cyclic shift field is used to generate the first reduced uplink DM-RS sequence and the second reduced uplink DM-RS sequence (DCI) decision value and a first orthogonal sequence based on a first downlink control field (DCI)
If the number of allocated resource block (s) is an odd number, the value of the first cyclic shift field is used to generate the third reduced uplink DM-RS sequence and the fourth reduced uplink DM-RS sequence Determining a second DCI-based CS decision value and a second orthogonal sequence,
Wherein the first DCI-based CS decision value and the first orthogonal sequence are generated by combining the remaining reduced uplink DM-RS sequence transmitted on the different layer with each of the first reduced uplink DM-RS sequence and the second reduced uplink The link DM-RS sequence is determined to be orthogonal,
Wherein the second DCI-based CS decision value and the second orthogonal sequence are generated by combining the remaining reduced uplink DM-RS sequence transmitted in the different layer with each of the third reduced uplink DM-RS sequence and the fourth reduced uplink The link DM-RS sequence is determined to be orthogonal,
The length of the first reduced uplink DM-RS sequence and the length of the second reduced uplink DM-RS sequence are respectively a multiple of 12,
Wherein the length of the third reduced uplink DM-RS sequence and the length of the fourth reduced uplink DM-RS sequence are respectively a multiple of six. The method according to claim 1,
The third reduced uplink DM-RS sequence and the fourth reduced uplink DM-RS are transmitted in the first layer,
The remaining reduced uplink DM-RS sequence is transmitted in at least one of a second layer, a third layer and a fourth layer,
Wherein the DCI-based CS decision value comprises a first DCI-based CS decision value for the first layer, a second DCI-based CS decision value for the second layer, a third DCI-based CS decision value for the third layer, A fourth DCI-based CS decision value for the fourth layer,
A modulo 12 computed value of the difference between the second DCI-based CS decision value and the first DCI-based CS decision value is 3,
The modulo 12 computation of the difference between the third DCI based CS decision value and the first DCI based CS decision value is 1,
Wherein the fourth DCI-based CS decision value and the first DCI-based CS decision value are modulo-12 calculated. The method according to claim 1,
The third reduced uplink DM-RS sequence and the fourth reduced uplink DM-RS are transmitted in the first layer,
The remaining reduced uplink DM-RS sequence is transmitted in at least one of a second layer, a third layer and a fourth layer,
Wherein the DCI-based CS decision value comprises a first DCI-based CS decision value for the first layer, a second DCI-based CS decision value for the second layer, a third DCI-based CS decision value for the third layer, A fourth DCI-based CS decision value for the fourth layer,
A modulo 12 computed value of the difference between the second DCI-based CS decision value and the first DCI-based CS decision value is 3,
A modulo 12 computed value of the difference between the third DCI-based CS decision value and the first DCI-based CS decision value is 2,
Wherein the value obtained by modulo-12 calculation of the difference between the fourth DCI-based CS decision value and the first DCI-based CS decision value is five. The method according to claim 1,
The cyclic shift of the first reduced uplink DM-RS sequence and the second reduced uplink DM-RS sequence is determined by the following equation (1)
&Quot; (1) &quot;

The cyclic shift of the third reduced uplink DM-RS sequence and the fourth reduced uplink DM-RS sequence is determined by the following equation (2)
&Quot; (2) &quot;

remind

Wherein the at least one DM-RS sequence has an integer value from 0 to 11 for each layer. The method according to claim 1,
The first reduced uplink DM-RS sequence and the second reduced uplink DM-RS are mapped to be transmitted only through one of the first slot and the second slot of the uplink subframe,
The first reduced uplink DM-RS sequence and the second reduced uplink DM-RS are generated based on the same reduced reference signal sequence,
The first uplink DM-RS sequence and the second uplink DM-RS sequence are transmitted on one single carrier-frequency division multiple access (FDMA) symbol constituting the resource block (s) in the one slot A method for determining an uplink DM-RS sequence that is mapped to cross each other in a frequency domain. In a UE performing an uplink DM (demodulation) -RS (reference signal) sequence determination method,
A radio frequency (RF) unit configured to transmit and receive a wireless signal; And
And a processor selectively coupled to the RF unit,
The processor receives information on the number of resource blocks (s) allocated for the reduced uplink DM-RS sequence in one slot of the uplink sub-frame,
And determines an uplink DM-RS sequence to be mapped to the uplink subframe based on information on the number of the allocated resource block (s)
If the number of allocated resource block (s) is an even number, the reduced uplink DM-RS sequence includes a first reduced uplink DM-RS sequence generated based on a value of a first cyclic shift field and a second reduced uplink DM- A reduced uplink DM-RS sequence,
If the number of the allocated resource block (s) is an odd number, the reduced uplink DM-RS sequence includes a third reduced uplink DM-RS sequence generated based on the value of the first cyclic shift field, 4 reduced uplink DM-RS sequence,
If the number of the allocated resource block (s) is even, the value of the first cyclic shift field is used to generate the first reduced uplink DM-RS sequence and the second reduced uplink DM-RS sequence (DCI) decision value and a first orthogonal sequence based on a first downlink control field (DCI)
If the number of allocated resource block (s) is an odd number, the value of the first cyclic shift field is used to generate the third reduced uplink DM-RS sequence and the fourth reduced uplink DM-RS sequence Determining a second DCI-based CS decision value and a second orthogonal sequence,
Wherein the first DCI-based CS decision value and the first orthogonal sequence are generated by combining the remaining reduced uplink DM-RS sequence transmitted on the different layer with each of the first reduced uplink DM-RS sequence and the second reduced uplink The link DM-RS sequence is determined to be orthogonal,
Wherein the second DCI-based CS decision value and the second orthogonal sequence are generated by combining the remaining reduced uplink DM-RS sequence transmitted in the different layer with each of the third reduced uplink DM-RS sequence and the fourth reduced uplink The link DM-RS sequence is determined to be orthogonal,
The length of the first reduced uplink DM-RS sequence and the length of the second reduced uplink DM-RS sequence are respectively a multiple of 12,
Wherein the length of the third reduced uplink DM-RS sequence and the length of the fourth reduced uplink DM-RS sequence are respectively a multiple of six. The method according to claim 6,
The third reduced uplink DM-RS sequence and the fourth reduced uplink DM-RS are transmitted in the first layer,
The remaining reduced uplink DM-RS sequence is transmitted in at least one of a second layer, a third layer and a fourth layer,
Wherein the DCI-based CS decision value comprises a first DCI-based CS decision value for the first layer, a second DCI-based CS decision value for the second layer, a third DCI-based CS decision value for the third layer, A fourth DCI-based CS decision value for the fourth layer,
A modulo 12 computed value of the difference between the second DCI-based CS decision value and the first DCI-based CS decision value is 3,
The modulo 12 computation of the difference between the third DCI based CS decision value and the first DCI based CS decision value is 1,
Wherein the value obtained by modulo 12 calculation of the difference between the fourth DCI-based CS decision value and the first DCI-based CS decision value is four. The method according to claim 6,
The third reduced uplink DM-RS sequence and the fourth reduced uplink DM-RS are transmitted in the first layer,
The remaining reduced uplink DM-RS sequence is transmitted in at least one of a second layer, a third layer and a fourth layer,
Wherein the DCI-based CS decision value comprises a first DCI-based CS decision value for the first layer, a second DCI-based CS decision value for the second layer, a third DCI-based CS decision value for the third layer, A fourth DCI-based CS decision value for the fourth layer,
A modulo 12 computed value of the difference between the second DCI-based CS decision value and the first DCI-based CS decision value is 3,
A modulo 12 computed value of the difference between the third DCI-based CS decision value and the first DCI-based CS decision value is 2,
Wherein the value obtained by modulo 12 calculation of the difference between the fourth DCI-based CS decision value and the first DCI-based CS decision value is five. The method according to claim 6,
The cyclic shift of the first reduced uplink DM-RS sequence and the second reduced uplink DM-RS sequence is determined by the following equation (1)
&Quot; (1) &quot;

The cyclic shift of the third reduced uplink DM-RS sequence and the fourth reduced uplink DM-RS sequence is determined by the following equation (2)
&Quot; (2) &quot;

remind

Wherein the at least one DM-RS sequence has an integer value from 0 to 11 for each layer. The method according to claim 6,
The first reduced uplink DM-RS sequence and the second reduced uplink DM-RS are mapped to be transmitted only through one of the first slot and the second slot of the uplink subframe,
The first reduced uplink DM-RS sequence and the second reduced uplink DM-RS are generated based on the same reduced reference signal sequence,
The first uplink DM-RS sequence and the second uplink DM-RS sequence are transmitted on one single carrier-frequency division multiple access (FDMA) symbol constituting the resource block (s) in the one slot A terminal that is mapped to cross each other in the frequency domain.

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