WO2016182378A1 - Method and wireless device for transmitting uplink control information - Google Patents

Abstract

An embodiment of the present invention provides a method for transmitting uplink control information (UCI) by a wireless device (user equipment) by means of a physical uplink control channel (PUCCH) in a carrier aggregation (CA) environment in which five or more carriers are aggregated. A method can comprise the steps of: determining, on the basis of the size of uplink control information, whether or not cyclical redundancy check (CRC) is to be generated; if CRC has been decided to be generated, generating CRC for detecting an error in the uplink control information; mapping the generated CRC and the uplink control information on a PUCCH; and transmitting the PUCCH on which the CRC and uplink control information have been mapped.

Description

Uplink control information transmission method and wireless device

The present invention relates to mobile communications.

Third Generation Partnership Project (3GPP) Long Term Evolution (LTE), an enhancement to the Universal Mobile Telecommunications System (UMTS), is being introduced as a 3GPP release 8. 3GPP LTE uses Orthogonal Frequency Division Multiple Access (OFDMA) in downlink and Single Carrier-Frequency Division Multiple Access (SC-FDMA) in uplink. In addition, 3GPP LTE employs a multiple input multiple output (MIMO) with up to four antennas.

As disclosed in 3GPP TS 36.211 V10.4.0 (2011-12) "Evolved Universal Terrestrial Radio Access (E-UTRA); Physical Channels and Modulation (Release 10)", the physical channel in LTE is a downlink channel PDSCH (Physical Downlink) It may be divided into a shared channel (PDCCH), a physical downlink control channel (PDCCH), a physical uplink shared channel (PUSCH) and a physical uplink control channel (PUCCH) which are uplink channels.

Meanwhile, 3GPP LTE-Advanced (LTE-A), an evolution of 3GPP LTE, introduces carrier aggregation (CA) that can aggregate up to five carriers to cope with rapidly increasing data traffic. It was. However, the aggregation of five carriers alone is limited in dealing with the rapidly increasing data traffic. Therefore, in next generation mobile communication systems, the aggregation of more than five carriers is under discussion.

However, when more than five carriers are aggregated in this manner, the number of bits of control information to be transmitted through the PUCCH is increased. In addition, an increase in the number of bits of control information to be transmitted has a problem of inevitably increasing the ripple effect when an error occurs.

One disclosure of the present specification is to generate a Cyclical Redundancy Check (CRC) for error detection of uplink control information (UCI), and to generate the generated CRC and uplink control information (UCI) by using a physical uplink control channel (PUCCH). It aims to provide a method of transmitting through).

Another object of the present disclosure is to provide a wireless device capable of generating a CRC for error detection of uplink control information (UCI) and transmitting the generated CRC and uplink control information (UCI) through a PUCCH. It is done.

In order to achieve the above object, one disclosure of the present specification provides a user equipment that uses a physical uplink control channel (PUCCH) in a carrier aggregation (CA) environment that aggregates five or more carriers. It provides a method for transmitting uplink control information (UCI) through. The method may include determining whether to generate a Cycical Redundancy Check (CRC) based on the size of the uplink control information (UCI), and when determining to generate the CRC, an error of the uplink control information (UCI). Generating a CRC for detection, mapping the generated CRC and the uplink control information (UCI) to the PUCCH, and transmitting a PUCCH to which the CRC and uplink control information are mapped. have.

The determining of whether to generate the CRC may flexibly determine the size of the CRC to be generated based on the size of the uplink control information (UCI).

The step of determining whether to generate the CRC determines the size of the CRC so that the size of the CRC increases as the size of the uplink control information (UCI) increases, the size of the uplink control information (UCI) If the size is greater than or equal to the set threshold size, the size of the CRC may be determined such that the size of the CRC decreases as the size of the uplink control information (UCI) increases.

The determining of whether to generate the CRC includes the HARQ (Hybrid Automatic Repeat reQuest) ACK (ACKnowledgement) / NACK (Non-ACKnowledgement) and periodic CSI report (Periodic Channel State Information report) in the uplink control information (UCI). If so, a single CRC can be generated for the HARQ ACK / NACK and the periodic CSI report.

In the determining of whether to generate the CRC, when a plurality of pieces of information are transmitted through the uplink control information (UCI), the CRC may be generated only for information having a greater than or equal to a critical importance among the plurality of pieces of information.

The generating of the CRC may include payload of uplink control information (UCI) after the interleaving or scrambling is performed when interleaving or scrambling is performed on the uplink control information (UCI). The CRC may be generated based on a payload.

The mapping of the CRC and uplink control information (UCI) may map the CRC and uplink control information (UCI) so that the CRC may be disposed at a position preceding the uplink control information (UCI). .

The method may further include masking an additional information sequence in the CRC, wherein the additional information sequence includes information on bundling HARQ ACK / NACK, information on a setting value of a periodic CSI report, It may include any one of information on a scheduling request (SR), information on whether interleaving or scrambling is applied.

When the additional information sequence includes information on whether interleaving or scrambling is applied, the additional information sequence may further include information about an application target of the interleaving or scrambling, an applied interleaving pattern, or a scrambling sequence.

In order to achieve the above object, another disclosure of the present disclosure, in uplink carrier aggregation (CA) environment that aggregates five or more carriers (CA), uplink control information (PU) through physical uplink control channel (PUCCH) Provides a wireless device for transmitting Control Information (UCI). The wireless device may include a radio frequency (RF) unit and a processor for controlling the RF unit. The processor may determine whether to generate a CRC based on the size of the uplink control information (UCI), and if it is determined to generate the CRC, the CRC for error detection of the uplink control information (UCI). Generating, mapping the generated CRC and the uplink control information (UCI) to the PUCCH, and transmitting a PUCCH to which the CRC and uplink control information are mapped.

According to the present disclosure, in a carrier aggregation (CA) environment in which five or more carriers are aggregated, the CRC is added to the uplink control information (UCI) for transmission, thereby minimizing an increase in the number of bits due to the addition of the CRC.

1 illustrates an example of a wireless communication system.

2 shows a structure of a radio frame according to FDD in 3GPP LTE.

3 is an exemplary diagram illustrating a resource grid in 3GPP LTE.

4 shows a structure of a downlink subframe in 3GPP LTE.

5 shows a structure of an uplink subframe in 3GPP LTE.

6 shows an example of a transmission region according to a PUCCH format.

FIG. 7A illustrates a channel structure of PUCCH format 1b in a normal CP.

7b shows a channel structure of a PUCCH format 2 / 2a / 2b in a normal CP.

7C shows a channel structure of PUCCH format 3. FIG.

8A and 8B illustrate an example of a structure of a subframe in which DMRS for a PUSCH is transmitted.

9 is an exemplary diagram illustrating an environment of a heterogeneous network in which a macro cell and a small cell are mixed.

10 is an exemplary diagram illustrating a concept of improved carrier aggregation (eCA).

FIG. 11 illustrates some embodiments of a CRC generation method when simultaneously transmitting a HARQ ACK / NACK and a periodic CSI report.

12 illustrates some embodiments of a CRC generation method according to the size of uplink control information (UCI).

13 shows an example of an arrangement order of uplink control information (UCI) and CRC.

14 is a flowchart illustrating a method of transmitting uplink control information (UCI) according to the present specification.

15 is a block diagram illustrating a wireless communication system in which the present disclosure is implemented.

Hereinafter, the present invention is applied based on 3rd Generation Partnership Project (3GPP) long term evolution (LTE) or 3GPP LTE-A (LTE-Advanced). This is merely an example, and the present invention can be applied to various wireless communication systems. Hereinafter, LTE includes LTE and / or LTE-A.

It is to be noted that the technical terms used herein are merely used to describe particular embodiments, and are not intended to limit the present invention. In addition, the technical terms used in the present specification should be interpreted as meanings generally understood by those skilled in the art unless they are specifically defined in this specification, and are overly inclusive. It should not be interpreted in the sense of or in the sense of being excessively reduced. In addition, when the technical terms used herein are incorrect technical terms that do not accurately represent the spirit of the present invention, it should be replaced with technical terms that can be understood correctly by those skilled in the art. In addition, the general terms used in the present invention should be interpreted as defined in the dictionary or according to the context before and after, and should not be interpreted in an excessively reduced sense.

Also, the singular forms used herein include the plural forms unless the context clearly indicates otherwise. In the present application, terms such as “consisting of” or “having” should not be construed as necessarily including all of the various components, or various steps described in the specification, and some of the components or some of the steps are included. It should be construed that it may not be, or may further include additional components or steps.

In addition, terms including ordinal numbers, such as first and second, as used herein may be used to describe various components, but the components should not be limited by the terms. The terms are used only for the purpose of distinguishing one component from another. For example, without departing from the scope of the present invention, the first component may be referred to as the second component, and similarly, the second component may also be referred to as the first component.

When a component is said to be "connected" or "connected" to another component, it may be directly connected to or connected to that other component, but other components may be present in between. On the other hand, when a component is said to be "directly connected" or "directly connected" to another component, it should be understood that there is no other component in between.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings, and the same or similar components will be given the same reference numerals regardless of the reference numerals, and redundant description thereof will be omitted. In addition, in describing the present invention, when it is determined that the detailed description of the related known technology may obscure the gist of the present invention, the detailed description thereof will be omitted. In addition, it should be noted that the accompanying drawings are only for easily understanding the spirit of the present invention and should not be construed as limiting the spirit of the present invention by the accompanying drawings. The spirit of the invention should be construed to extend to all changes, equivalents, and substitutes in addition to the accompanying drawings.

As used herein, a base station (base station) generally refers to a fixed station for communicating with a wireless device, and includes an evolved-nodeb (eNodeB), an evolved-nodeb (eNB), and a base transceiver system (BTS). It may be called in other terms such as an access point.

Further, hereinafter, the term UE (User Equipment), which is used, may be fixed or mobile, and may include a device, a wireless device, a terminal, a mobile station (MS), and a user terminal (UT). It may be called in other terms such as Subscriber Station (SS) and Mobile Terminal (MT).

1 illustrates an example of a wireless communication system.

As can be seen with reference to FIG. 1, a wireless communication system includes at least one base station (BS) 20. Each base station 20 provides a communication service for a particular geographic area (generally called a cell) 20a, 20b, 20c. The cell can in turn be divided into a number of regions (called sectors).

The UE 10 typically belongs to one cell, and the cell to which the UE 10 belongs is called a serving cell. A base station that provides a communication service for a serving cell is called a serving BS. Since the wireless communication system is a cellular system, there are other cells adjacent to the serving cell. Another cell adjacent to the serving cell is called a neighbor cell. A base station that provides communication service for a neighbor cell is called a neighbor BS. The serving cell and the neighbor cell are determined relatively based on the UE.

Hereinafter, downlink (DL) means communication from the base station 20 to the UE 10, and uplink (UL) means communication from the UE 10 to the base station 20. In downlink, the transmitter may be part of the base station 20 and the receiver may be part of the UE 10. In uplink, the transmitter may be part of the UE 10 and the receiver may be part of the base station 20.

On the other hand, a wireless communication system can be largely divided into a frequency division duplex (FDD) method and a time division duplex (TDD) method. According to the FDD scheme, uplink transmission and downlink transmission are performed while occupying different frequency bands. According to the TDD scheme, uplink transmission and downlink transmission are performed at different times while occupying the same frequency band. The channel response of the TDD scheme is substantially reciprocal. This means that the downlink channel response and the uplink channel response are almost the same in a given frequency domain. Therefore, in a TDD based wireless communication system, the downlink channel response can be obtained from the uplink channel response. In the TDD scheme, since the uplink transmission and the downlink transmission are time-divided in the entire frequency band, the downlink transmission by the base station and the uplink transmission by the UE cannot be performed at the same time. In a TDD system in which uplink transmission and downlink transmission are divided into subframe units, uplink transmission and downlink transmission are performed in different subframes.

Hereinafter, the LTE system will be described in more detail.

2 is 3GPP In LTE  A structure of a radio frame according to FDD is shown.

The radio frame illustrated in FIG. 2 may refer to section 5 of 3GPP TS 36.211 V10.4.0 (2011-12) "Evolved Universal Terrestrial Radio Access (E-UTRA); Physical Channels and Modulation (Release 10)".

Referring to FIG. 2, a radio frame includes 10 subframes, and one subframe includes two slots. Slots in a radio frame are numbered from 0 to 19 slots. The time taken for one subframe to be transmitted is called a transmission time interval (TTI). TTI may be referred to as a scheduling unit for data transmission. For example, one radio frame may have a length of 10 ms, one subframe may have a length of 1 ms, and one slot may have a length of 0.5 ms.

The structure of the radio frame is merely an example, and the number of subframes included in the radio frame or the number of slots included in the subframe may be variously changed.

Meanwhile, one slot may include a plurality of orthogonal frequency division multiplexing (OFDM) symbols. How many OFDM symbols are included in one slot may vary depending on a cyclic prefix (CP). One slot in a normal CP includes 7 OFDM symbols, and one slot in an extended CP includes 6 OFDM symbols. Here, the OFDM symbol is only for representing one symbol period in the time domain because 3GPP LTE uses Orthogonal Frequency Division Multiple Access (OFDMA) in downlink (DL), and multiple access scheme or name There is no limit on. For example, the OFDM symbol may be called by other names such as a single carrier-frequency division multiple access (SC-FDMA) symbol, a symbol period, and the like.

3 is 3GPP In LTE  Representation of the resource grid It is an illustration .

Referring to FIG. 3, a slot includes a plurality of OFDM symbols in a time domain and N _RB resource blocks ( _RBs ) in a frequency domain. For example, in the LTE system, the number of resource blocks (RBs), that is, N _RBs may be any one of 6 to 110.

The RB is a resource allocation unit and includes a plurality of subcarriers in one slot. For example, if one slot includes 7 OFDM symbols in the time domain and the resource block includes 12 subcarriers in the frequency domain, one resource block includes 7 × 12 resource elements (REs). It may include.

Meanwhile, the number of subcarriers in one OFDM symbol may be selected and used among 128, 256, 512, 1024, 1536, and 2048.

In 3GPP LTE of FIG. 3, a resource grid for one uplink slot may be applied to a resource grid for a downlink slot.

4 is 3GPP In LTE  This indicates the structure of a downlink subframe.

In FIG. 4, seven OFDM symbols are included in one slot by assuming a normal CP.

The DL subframe is divided into a control region and a data region in the time domain. The control region includes up to three OFDM symbols preceding the first slot in the subframe, but the number of OFDM symbols included in the control region may be changed. The physical downlink control channel (PDCCH) and other control channels are allocated to the control region, and the physical downlink shared channel (PDSCH) is allocated to the data region.

In 3GPP LTE, physical channels include physical downlink shared channels (PDSCHs), physical uplink shared channels (PUSCHs), physical downlink control channels (PDCCHs), physical control format indicator channels (PCFICH), and physical hybrids (PHICH). ARQ Indicator CHannel) and PUCCH (Physical Uplink Control CHannel).

5 is 3GPP In LTE  This indicates the structure of an uplink subframe.

Referring to FIG. 5, an uplink (UL) subframe may be divided into a control region and a data region in a frequency domain. A physical uplink control channel (PUCCH) for transmitting uplink control information is allocated to the control region. The data region is allocated a PUSCH (Physical Uplink Shared CHannel) for transmitting data (in some cases, control information may also be transmitted).

PUCCH for one UE is allocated to an RB pair in a subframe. Resource blocks belonging to a resource block pair occupy different subcarriers in each of a first slot and a second slot. The frequency occupied by RBs belonging to the RB pair allocated to the PUCCH is changed based on a slot boundary. This is called that the RB pair allocated to the PUCCH is frequency-hopped at the slot boundary.

The UE may obtain frequency diversity gain by transmitting uplink control information through different subcarriers over time. m is a location index indicating a logical frequency domain location of a resource block pair allocated to a PUCCH in a subframe.

The uplink control information transmitted on the PUCCH includes HARQ (Hybrid Automatic Repeat reQuest) ACK (Non-ACKnowledgement) / NACK (Non-ACKnowledgement), Channel Quality Indicator (CQI) indicating the downlink channel state, scheduling that is an uplink radio resource allocation request. Scheduling Request (SR).

The PUSCH is mapped to an uplink-shared channel (UL-SCH) which is a transport channel. The uplink data transmitted on the PUSCH may be a transport block which is a data block for the UL-SCH transmitted during the transmission time interval (TTI). The transport block may be user information. Alternatively, the uplink data may be multiplexed data. The multiplexed data may be multiplexed of a transport block and control information for the UL-SCH. For example, control information multiplexed with data may include CQI, Precoding Matrix Indicator (PMI), HARQ, and Rank Indicator (RI). Or, the uplink data may consist of control information only.

6 PUCCH  Represents the transmission area according to the format It is an illustration .

The PUCCH formats will be described with reference to FIG. 6.

PUCCH format 1 carries a scheduling request (SR). In this case, an OOK (On-Off Keying) method may be applied. PUCCH format 1a carries ACK / NACK (Acknowledgement / Non-Acknowledgement) modulated by a Binary Phase Shift Keying (BPSK) scheme for one codeword. PUCCH format 1b carries ACK / NACK modulated by Quadrature Phase Shift Keying (QPSK) for two codewords. PUCCH format 2 carries a channel quality indicator (CQI) modulated in a QPSK scheme. PUCCH formats 2a and 2b carry CQI and ACK / NACK.

The table below shows the PUCCH format.

format	Modulation method	Total number of bits per subframe	Explanation
Format 1	Undefined	Undefined	Scheduling Request (SR)
Format 1a	BPSK	One	ACK / NACK of 1-bit HARQ, with or without SR
Format 1b		QPSK	2	ACK / NACK of 2 bit HARQ, with or without SR
Format 2	QPSK	20	CSI and 1 or 2 bits HARQ ACK / NACK for Extended CP
Format 2a	QPSK + BPSK	21	CSI and 1 bit HARQ ACK / NACK
Format 2b	QPSK + BPSK	22	CSI and 2-bit HARQ ACK / NACK
Format 3	QPSK	48	There may or may not be multiple ACK / NACKs and CSI, SR for carrier aggregation

Each PUCCH format is mapped to a PUCCH region and transmitted. For example, the PUCCH format 2 / 2a / 2b is mapped and transmitted to resource blocks (resource blocks having m = 0 and 1 in FIG. 6) allocated to the terminal. A mixed PUCCH resource block (mixed PUCCH RB) may be transmitted by being mapped to an adjacent resource block (for example, m = 2 resource block) in the center direction of the band to the resource block to which the PUCCH format 2 / 2a / 2b is allocated. . PUCCH format 1 / 1a / 1b through which SR and ACK / NACK are transmitted may be arranged in an Rb with m = 4 or m = 5. The number of resource blocks (NRBs) that can be used in PUCCH format 2 / 2a / 2b through which CQI is transmitted may be indicated to the UE through the broadcast signal.

7a normal  From CP PUCCH  The channel structure of the format 1b is shown.

One slot includes seven OFDM symbols, and three OFDM symbols become a reference signal for demodulation, that is, a DeModulation Reference Signal (DMRS) OFDM symbol, and four OFDM symbols are data OFDM symbols for an ACK / NACK signal. do.

In PUCCH format 1b, a modulation symbol d (0) is generated by modulating an encoded 2-bit ACK / NACK signal with Quadrature Phase Shift Keying (QPSK).

Cyclic Shift (CS) index I _cs may vary according to slot number n _s in a radio frame and / or symbol index 1 in slot.

Having four data OFDM symbols for transmission of the ACK / NACK signal in a slot in the normal CP, the Let cyclic shifts corresponding to indexes in each of the data OFDM symbols _cs0 I, I _{cs1, cs2} I, I _cs3.

The modulation symbol d (0) is spread to the cyclically shifted sequence r (n, I _cs ). When the one-dimensional spread sequence corresponding to the (i + 1) -th OFDM symbol in the slot is m (i),

{m (0), m (1), m (2), m (3)} = {d (0) r (n, I _cs0 ), d (0) r (n, I _cs1 ), d (0 ) r (n, I _cs2 ), d (0) r (n, I _cs3 )}.

In order to increase the terminal capacity, the one-dimensional spread sequence may be spread using an orthogonal sequence. An orthogonal sequence w _i (k) where spreading factor K = 4, where i is a sequence index, 0 ≦ k ≦ K−1, uses the following sequence.

Index (i)	K = 4	K = 3
	[w i (0), w i (1), w i (2), w i (3)]	[w i (0), w i (1), w i (2)]
0	[+1, +1, +1, +1]	[+1, +1, +1]
One	[+1, -1, +1, -1]	[+1, e j2 ∏ / 3 , e j4 ∏ / 3 ]
2	[+1, -1, -1, +1]	[+1, e j4 ∏ / 3 , e j2 ∏ / 3 ]

Different spreading coefficients may be used for each slot.

Therefore, given any orthogonal sequence index i, the two-dimensional spreading sequence {s (0), s (1), s (2), s (3)} can be expressed as follows.

{s (0), s (1), s (2), s (3)} = {w _i (0) m (0), w _i (1) m (1), w _i (2) m ( 2), w _i (3) m (3)}

Two-dimensional spread sequences {s (0), s (1), s (2), s (3)} are transmitted in the corresponding OFDM symbol after IFFT (Inverse Fast Fourier transform) is performed. As a result, the ACK / NACK signal is transmitted on the PUCCH.

The reference signal of the PUCCH format 1b is also transmitted by shifting the base sequence r (n) by cyclic shift and spreading it in an orthogonal sequence. When the cyclic shift indexes corresponding to three RS OFDM (Reference Signal OFDM) symbols are I _cs4 , I _cs5 , and I _cs6 , three cyclic shifted sequences r (n, I _cs4 ) and r (n, I _cs5 ), r (n, I _cs6 ) can be obtained. These three circular shifted sequences are spread to the orthogonal sequence w ^RS _i (k) with K = 3.

The orthogonal sequence index i, the cyclic shift index I _cs, and the resource block index m are parameters necessary for configuring a PUCCH and are resources used to distinguish a PUCCH (or a terminal). If the number of available cyclic shifts is 12 and the number of available orthogonal sequence indexes is 3, PUCCHs for a total of 36 terminals may be multiplexed into one resource block.

In 3GPP LTE, a resource index n ⁽¹⁾ _PUCCH is defined so that the UE acquires the three parameters for configuring the _PUCCH . Resource index n ⁽¹⁾ _PUCCH = n _CCE + N ⁽¹⁾ _PUCCH , where n _CCE is a downlink resource allocation (DCI) for scheduling downlink data corresponding to a corresponding PDCCH (ie, ACK / NACK signal). Is the number of the first CCE used for transmission of the PDCCH including N, where N ⁽¹⁾ _PUCCH is a parameter that the base station informs the terminal in an upper layer message.

The time, frequency, and code resources used for transmitting the ACK / NACK signal are called ACK / NACK resources or PUCCH resources. As described above, the index of the ACK / NACK resource (referred to as ACK / NACK resource index or PUCCH index) required for transmitting the ACK / NACK signal on the PUCCH is orthogonal sequence index i, cyclic shift index I _cs , resource block At least one of the index m and the index for obtaining the three indexes. The ACK / NACK resource may include at least one of an orthogonal sequence, a cyclic shift, a resource block, and a combination thereof.

7b is normal  From CP PUCCH  format 2 / 2a A channel structure of / 2b is shown.

Referring to FIG. 7B, in the normal CP, OFDM symbols 1 and 5 (ie, second and sixth OFDM symbols) are used for a reference signal (DMRS) for demodulation and the remaining OFDM symbols are used for CQI transmission. In the case of an extended CP, OFDM symbol 3 (ie, a fourth symbol) is used for DMRS.

Ten CQI information bits are channel coded, for example, at a 1/2 code rate, resulting in 20 coded bits. Reed-Muller code may be used for channel coding. After scrambling, QPSK constellation mapping is performed to generate QPSK modulation symbols (d (0) to d (4) in slot 0). Each QPSK modulation symbol is modulated with a cyclic digit shift of a length 12 basic RS sequence r (n) and then IFFT and transmitted in each of the 10 SC-FDMA symbols in the subframe. 12 uniformly spaced cyclic shifts allow 12 different terminals to be orthogonally multiplexed in the same PUCCH resource block. As the RS sequence applied to the OFDM symbols 1 and 5, a basic RS sequence r (n) having a length of 12 may be used.

7c PUCCH  The channel structure of format 3 is illustrated.

Referring to FIG. 7C, PUCCH format 3 is a PUCCH format using a block spreading technique. The block spreading technique is a method of spreading a symbol sequence obtained by modulating multi-bit ACK / NACK in a time domain using a block spreading code.

In PUCCH format 3, a symbol sequence (for example, an ACK / NACK symbol sequence) is spread and transmitted in the time domain by a block spreading code. An orthogonal cover code (OCC) may be used as the block spreading code. Control signals d of various terminals may be multiplexed by the block spreading code. In PUCCH format 2, symbols transmitted in each data symbol (for example, d (0), d (1), d (2), d (3), d (4), etc.) of FIG. 7B are different, and CAZAC ( While UE multiplexing is performed using a cyclic digit shift of a constant amplitude zero auto-correlation) sequence, in PUCCH format 3, a symbol sequence consisting of one or more symbols is transmitted over a frequency domain of each data symbol, and a block spreading code There is a difference in spreading in the time domain by performing UE multiplexing. In FIG. 7C, a case in which two DMRS symbols are used in one slot is illustrated. However, the present invention is not limited thereto, and an orthogonal cover code having three DMRS symbols and a spreading factor value of 4 may be used. The DMRS symbol may be generated from a CAZAC sequence having a specific cyclic shift and may be transmitted in a form in which a plurality of DMRS symbols in a time domain are multiplied by a specific orthogonal cover code.

<Uplink Reference Signal>

Hereinafter, an uplink reference signal (RS) will be described.

Reference signals are generally transmitted in sequence. The sequence of the reference signal may be any sequence without particular limitation. The reference signal sequence may use a PSK-based computer generated sequence. Examples of PSKs include binary phase shift keying (BPSK) and quadrature phase shift keying (QPSK). Alternatively, the reference signal sequence may use a constant amplitude zero auto-correlation (CAZAC) sequence. Examples of CAZAC sequences are ZC-based sequences, ZC sequences with cyclic extensions, ZC sequences with truncation, etc. There is this. Alternatively, the reference signal sequence may use a pseudo-random (PN) sequence. Examples of PN sequences include m-sequences, computer generated sequences, Gold sequences, and Kasami sequences. In addition, the reference signal sequence may use a cyclically shifted sequence.

The uplink reference signal may be divided into a demodulation reference signal (DMRS) and a sounding reference signal (SRS). DMRS is a reference signal used for channel estimation for demodulation of a received signal. DMRS may be combined with transmission of PUSCH or PUCCH. The SRS is a reference signal transmitted by the terminal to the base station for uplink scheduling. The base station estimates an uplink channel through the received sounding reference signal and uses the estimated uplink channel for uplink scheduling. SRS is not combined with transmission of PUSCH or PUCCH. The same kind of base sequence can be used for DMRS and SRS. Meanwhile, precoding applied to DMRS in uplink multi-antenna transmission may be the same as precoding applied to PUSCH. Cyclic shift separation is a primary scheme for multiplexing DMRS. In the 3GPP LTE-A system, the SRS may not be precoded and may also be a reference signal specific to the antenna.

The reference signal sequence r _{u, v} ^(α) (n) may be defined based on the basic sequence b _{u, v} (n) and the cyclic shift α by the following equation.

In Equation 1, M _sc ^RS = m * N _sc ^RB (1 ≦ m ≦ N _RB ^{max, UL} ) is a length of a reference signal sequence. N _sc ^RB represents the size of a resource block represented by the number of subcarriers in the frequency domain, and N _RB ^{max, UL} represents the maximum value of an uplink bandwidth expressed in multiples of N _sc ^RB . The plurality of reference signal sequences may be defined by differently applying α, which is a cyclic shift value, from one basic sequence.

The basic sequence b _{u, v} (n) is divided into a plurality of groups, where u∈ {0,1,... , 29} represents a group number, and v represents a basic sequence number within a group. The base sequence depends on the length of the base sequence (M _sc ^RS ). Each group of the length for which 1 ≤ m ≤ 5 a, and a length with respect to m contains one base sequence (v = 0) of M _sc ^RS 6 ≤ m ≤ n _RB ^{max, UL} m M _sc ^RS It contains two basic sequences (v = 0, 1). The sequence group number u and the base sequence number v in the group may change over time, such as group hopping or sequence hopping.

When the length of the reference signal sequence is 3N _sc ^RB or more, the basic sequence may be defined by the following equation.

In the above equation, q represents the root index of the ZCoff (Zadoff-Chu) sequence. N _ZC ^RS is the length of the ZC sequence and may be given as a maximum prime number smaller than M _sc ^RS . The ZC sequence having the root index q may be defined by Equation 4.

In the above equation q may be given by the following equation.

When the length of the reference signal sequence is 3N _sc ^RB or less, the basic sequence may be defined by the following equation.

The following table is an example of defining φ (n) when M _sc ^RS = N _sc ^RB .

The following table is an example of defining φ (n) when M _sc ^RS = 2 * N _sc ^RB .

Hopping of the reference signal may be applied as follows.

The sequence group number u of the slot n _s may be defined based on the group hopping pattern f _gh (n _s ) and the sequence shift pattern f _ss by the following equation.

There may be 17 different group hopping patterns and 30 different sequence shift patterns. Group hopping may or may not be applied by Group-hopping-enabled parameters, which are cell specific parameters provided by higher layers. In addition, group hopping for the PUSCH may not be applied to a specific UE by a disable-sequence-group-hopping parameter which is a UE-specific parameter. PUCCH and PUSCH may have the same group hopping pattern and may have different sequence shift patterns.

The group hopping pattern f _gh (n _s ) is the same for PUSCH and PUCCH and may be defined by the following equation.

In the above equation, c (i) is a pseudo-random sequence that is a PN sequence and may be defined by a Gold sequence of length-31. Equation below shows an example of the gold sequence c (n).

Where Nc = 1600, x ₁ (i) is the first m-sequence and x ₂ (i) is the second m-sequence. A pseudo random sequence generator is used at the beginning of each radio frame

Can be initialized to

The definition of the sequence shift pattern f _ss may be different for PUCCH and PUSCH. The sequence shift pattern f _ss ^{PUCCH of the PUCCH} may be given as ^PUCCH = N _ID ^cell mod 30. The sequence shift pattern f _ss ^PUSCH = (f _ss ^PUCCH + Δ _ss ) mod 30 of the ^PUSCH may be given by Δ _ss ∈ {0, 1,... , 29} may be configured by a higher layer.

Sequence hopping can be applied only to a reference signal sequence whose length is longer than 6N _sc ^RB . For a reference signal sequence whose length is shorter than 6N _sc ^RB , the base sequence number v = 0 in the base sequence group is given. For a reference signal sequence whose length is longer than 6N _sc ^RB , the base sequence number v in the base sequence group in slot n _s may be defined by Equation 9.

c (i) may be represented by the example of Equation 8 above. Sequence hopping may or may not be applied by Sequence-hopping-enabled parameters, which are cell specific parameters provided by higher layers. In addition, sequence hopping for the PUSCH may not be applied to a specific UE by a Disable-sequence-group-hopping parameter which is a UE-specific parameter. A pseudo random sequence generator is used at the beginning of each radio frame

Can be initialized to

The PUSCH DMRS sequence r _PUSCH ^(λ) (.) According to the layer λ (0,1, ..., γ-1) may be defined by Equation 10.

In the above equation m = 0,1,... N = 0,... , M _sc ^RS -1. M _sc ^RS = M _sc ^PUSCH . The orthogonal sequence w ^(λ) (m) may be determined according to the table described below.

The cyclic shift in the slot n _s is given by α = 2πn _cs / 12, n _cs can be defined by the following equation.

In the above equation, n ⁽¹⁾ _DMRS may be determined according to a cyclicShift parameter provided by a higher layer. The table below shows an example of n ⁽¹⁾ _DMRS determined according to the cyclicShift parameter.

Parameter		n (1) DMRS
0	0
One	2
2	3
3	4
4	6
5	8
6	9
7	10

In the above equation, n ⁽²⁾ _{DMRS, λ} may be determined by a DMRS cyclic shift field in DCI format 0 for a transport block according to a corresponding PUSCH transmission. The following table is an example of n ⁽²⁾ _{DMRS, λ} determined according to the DMRS cyclic shift field.

	n (2) DMRS, λ				[w (λ) (0) w (λ) (1)]
DMRS circular shift field	λ = 0	λ = 1	λ = 2	λ = 3	λ = 0	λ = 1	λ = 2	λ = 3
000	0	6	3	9	[1 1]	[1 1]	[1 -1]	[1 -1]
001	6	0	9	3	[1 -1]	[1 -1]	[1 1]	[1 1]
010	3	9	6	0	[1 -1]	[1 -1]	[1 1]	[1 1]
011	4	10	7	One	[1 1]	[1 1]	[1 1]	[1 1]
100	2	8	5	11	[1 1]	[1 1]	[1 1]	[1 1]
101	8	2	11	5	[1 -1]	[1 -1]	[1 -1]	[1 -1]
110	10	4	One	7	[1 -1]	[1 -1]	[1 -1]	[1 -1]
111	9	3	0	6	[1 1]	[1 1]	[1 -1]	[1 -1]

n _PN (n _s ) may be defined by the following equation.

c (i) may be represented by the example of Equation 8 above, and may be applied cell-specific of c (i). A pseudo random sequence generator is used at the beginning of each radio frame

Can be initialized to

The vector of the reference signal may be precoded by the following equation.

In the above equation, P is the number of antenna ports used for PUSCH transmission. W is a precoding matrix. P = 1, W = 1, γ = 1 for PSUCH transmission using a single antenna port. Also, P = 2 or 4 for spatial multiplexing.

For each antenna port used for PUSCH transmission, the DMRS sequence is multiplied by an amplitude scaling factor β _PUSCH and mapped in order to the resource block. The set of physical resource blocks used for mapping is the same as the set of physical resource blocks used for corresponding PUSCH transmission. Within the subframe, the DMRS sequence may first be mapped to a resource element in an increasing direction in the frequency domain and in a direction in which the slot number increases. The DMRS sequence may be mapped to a fourth SC-FDMA symbol (SC-FDMA symbol index 3) in the case of a normal CP and a third SC-FDMA symbol (SC-FDMA symbol index 2) in the case of an extended CP.

8A and 8B PUSCH  for DMRS  An example of the structure of a transmitted subframe.

The structure of the subframe of FIG. 8A shows a case of a normal CP. The subframe includes a first slot and a second slot. Each of the first slot and the second slot includes seven SC-FDMA symbols. Fourteen SC-FDMA symbols in a subframe are symbol indexed from 0 to 13. Reference signals may be transmitted over SC-FDMA symbols with symbol indices of 3 and 10. The reference signal may be transmitted using a sequence. A ZCoff (Zadoff-Chu) sequence may be used as the reference signal sequence, and various ZC sequences may be generated according to a root index and a cyclic shift value. The base station may estimate different channels of the plurality of UEs through an orthogonal sequence or a quasi-orthogonal sequence by allocating different cyclic shift values to the UE. The positions of the frequency domains occupied by the reference signal in the two slots in the subframe may be the same or different. The same reference signal sequence is used in two slots. Data may be transmitted through the remaining SC-FDMA symbols except for the SC-FDMA symbol to which the reference signal is transmitted.

The structure of the subframe of FIG. 8B shows a case of an extended CP. The subframe includes a first slot and a second slot. Each of the first slot and the second slot includes six SC-FDMA symbols. Twelve SC-FDMA symbols in the subframe are symbol indexed from 0 to 11. Reference signals are transmitted over SC-FDMA symbols with symbol indices of 2 and 8. Data is transmitted through the remaining SC-FDMA symbols except for the SC-FDMA symbol to which the reference signal is transmitted.

<Carrier aggregation>

A carrier aggregation (CA) system will now be described.

The carrier aggregation system refers to aggregating a plurality of component carriers (CC). By the carrier aggregation, the meaning of the existing cell has been changed. According to carrier aggregation, a cell may mean a combination of a downlink component carrier and an uplink component carrier or a single downlink component carrier.

In the carrier aggregation, a cell may be divided into a primary cell, a secondary cell, and a serving cell. A primary cell means a cell operating at a primary frequency, and is a cell in which a UE performs an initial connection establishment procedure or a connection reestablishment procedure with a base station, or a handover procedure in a handover procedure. It means the cell indicated by the head cell. The secondary cell refers to a cell operating at the secondary frequency. Once the RRC (Radio Resource Control) connection is established, the secondary cell is established and used to provide additional radio resources.

As described above, in the carrier aggregation system, unlike a single carrier system, a plurality of CCs, that is, a plurality of serving cells, may be supported.

Such a carrier aggregation system may support cross-carrier scheduling. Cross-carrier scheduling is a resource allocation of a PDSCH transmitted on another component carrier through a PDCCH transmitted on a specific component carrier and / or other components other than the component carrier basically linked with the specific component carrier. A scheduling method for resource allocation of a PUSCH transmitted through a carrier.

Introduction of small cells

Meanwhile, in the next generation mobile communication system, in order to process more traffic, a small cell having a small cell coverage radius is expected to be added within the coverage of the existing cell. Since the existing cell has greater coverage than the small cell, it may be referred to as a macro cell. Hereinafter, a description will be given with reference to FIG. 9.

9 illustrates an environment of a heterogeneous network in which macro and small cells are mixed. It is an illustration .

Referring to FIG. 9, the macro cell of the existing base station 200 is a heterogeneous network environment in which a macro cell overlaps with a small cell of one or more small base stations 300a, 300b, 300c, and 300d. Since the existing base station provides greater coverage than the small base station, it is also called a macro base station (Macro eNodeB, MeNB). In this specification, the terms macro cell and macro base station are used interchangeably. The UE connected to the macro cell 200 may be referred to as a macro UE. The macro UE receives a downlink signal from the macro base station and transmits an uplink signal to the macro base station.

In such a heterogeneous network, the coverage gap of the macrocell can be filled by setting the macrocell as a primary cell and setting the small cell as a secondary cell. In addition, by setting the small cell as the primary cell (Pcell) and the macro cell as the secondary cell (Scell), it is possible to improve the overall performance (boosting).

Meanwhile, the small cell may use a frequency band currently allocated to LTE / LTE-A or use a higher frequency band (eg, a band of 3.5 GHz or more). On the other hand, in the future LTE-A system, the small cell is not used independently, it is also considered to use only as a macro-assisted small cell (macro-assisted small cell) that can be used with the help of the macro cell.

Such small cells 300a, 300b, 300c, and 300d may have a similar channel environment, and because they are located at close distances to each other, interference between small cells may be a big problem.

To reduce this interference effect, small cells 300b and 300c may expand or reduce their coverage. Such expansion and contraction of coverage is called cell breathing. For example, as shown, the small cells 300b and 300c may be turned on or off depending on the situation.

<Enhanced Carrier Aggregation: eCA )>

10 shows improved carrier aggregation ( eCA Representing the concept of It is an illustration .

As shown in FIG. 10, in the next system, for improving the existing carrier aggregation (CA) that could aggregate up to five carriers for the purpose of supporting a rapidly increasing amount of downlink traffic, up to X carriers Considering to aggregate. Here, the value of X may be 8, 16, or 32.

However, such an increase in the number of aggregated carriers may rapidly increase the number of bits for uplink control information (UCI) such as HARQ ACK / NACK or channel state information (CSI). In addition, an increase in the number of bits for the uplink control information (UCI) may increase the ripple effect when an error occurs. Therefore, the next system considers introducing a Cycical Redundancy Check (CRC) when transmitting uplink control information (UCI) such as HARQ ACK / NACK or CSI through PUCCH. In this case, the base station can check the error of the uplink control information (UCI) through the CRC check after the PUCCH detection.

<Disclosure of this specification>

One disclosure of the present specification proposes a mapping method for transmitting a CRC in transmitting uplink control information (UCI). In addition, one disclosure of the present specification proposes a method for generating a CRC upon simultaneous transmission of HARQ ACK / NACK and CSI. In the present specification, the size of the CRC may be 4, 8, or 16 bits, and may be a single parity bit. The generator polynomial for CRC generation can use D + 1 if the CRC is a single parity bit, D ⁴ + D + 1 if the CRC is 4 bits, and 8 bits for the CRC. You can also use D ⁸ + D ⁷ + D ⁴ + D ³ + D + 1.

<CRC generation method>

The CRC can be used for error detection, but since the number of bits transmitted through the PUCCH can be increased, a suitable generation method and a transmission method need to be considered. In the next system, it may be considered to simultaneously transmit HARQ ACK / NACK and a single or a plurality of periodic CSI reports through the PUCCH. Alternatively, it may be considered to simultaneously transmit a plurality of periodic CSI reports on the PUCCH. The following describes a method of generating a CRC when simultaneously transmitting a HARQ ACK / NACK and a periodic CSI report.

11 is HARQ ACK Of NACK  And simultaneous periodic CSI reporting CRC  Some of the produce way Example  Indicates.

1) As illustrated in (a) of FIG. 11, a single CRC may be generated for HARQ ACK / NACK and periodic CSI reporting to be transmitted through PUCCH. That is, when an error occurs in HARQ ACK / NACK or periodic CSI report, the error may be detected through the CRC. In this case, it is unknown whether any uplink control information (UCI) has caused an error, but there is an advantage that the number of CRC bits can be efficiently used.

2) As shown in FIG. 11B, a CRC may be generated only for HARQ ACK / NACK, and a CRC may not be generated for periodic CSI reporting. Basically, HARQ ACK / NACK and periodic CSI reporting have different performance requirements. In addition, since HARQ ACK / NACK is generally considered as more important information than periodic CSI reporting, even when HARQ ACK / NACK and periodic CSI reporting are simultaneously transmitted, it is considered to detect only an error of HARQ ACK / NACK through CRC. Can be.

3) As shown in FIG. 11C, a CRC for each of HARQ ACK / NACK and a periodic CSI report can be generated. However, by generating different lengths of CRC for each of the HARQ ACK / NACK and the periodic CSI report, the degree of error detection for each of the HARQ ACK / NACK and the periodic CSI report can be changed. However, in this case, due to an increase in the number of bits due to the CRC, the error correction capability for the PUCCH itself may be reduced. Meanwhile, when there are a plurality of periodic CSI reports, a single CRC may be generated for the entire periodic CSI report, and a separate CRC may be generated for each. Furthermore, when there are a plurality of periodic CSI reports, a plurality of CRCs of different lengths may be generated for each of the plurality of periodic CSI reports on the basis of group (group) or reporting type (reporting type).

The HARQ ACK / NACK and the periodic CSI report as described above are just one example, and are not the HARQ ACK / NACK, the periodic CSI report, but the first uplink control information (UCI) and the second uplink control information (UCI). It can be expressed as. In addition, it may be assumed that the first uplink control information UCI has a higher priority or importance than the second uplink control information UCI.

As another example of the CRC generation method according to the present specification, a CRC may be generated only for a RI (Rank Indicator), and a CRC may not be generated for periodic CSI reporting. As another example of the CRC generation method, a CRC is generated for uplink control information (UCI) for a primary cell (Pcell) or a group including a primary cell, and a CRC is generated for other cells or other groups. May not be created.

More specifically, the first uplink control information (UCI) and the second uplink control information (UCI) may be the same type of uplink control information (UCI), constant of the same type of uplink control information (UCI) CRC can be generated for each size. For example, the first uplink control information (UCI) and the second uplink control information (UCI) are set to different subsets within the payload of the same HACK ACK / NACK, each of CRCs for the first uplink control information (UCI) and the second uplink control information (UCI) may be generated. In this case, when an error occurs in some CRCs, it is possible to prevent the entirety from being processed as NACK, which may be advantageous in terms of ACK-to-NACK errors. Meanwhile, the first uplink control information (UCI) and the second uplink control information (UCI) may be encoded through the same encoder, but may be encoded through independent encoders. May be

Meanwhile, when the scheduling request SR is encoded and transmitted through the same encoder together with the HARQ ACK / NACK, the scheduling request SR may be treated like the HARQ ACK / NACK and the CRC may be generated together. ) And a separate CRC for HARQ ACK / NACK. Here, when generating separate CRCs for the scheduling request SR and the HARQ ACK / NACK, the CRC may not be generated for the scheduling request SR. In addition, when the periodic CSI report is simultaneously transmitted with HARQ ACK / NACK, a CRC may be generated together with the periodic CSI report and the scheduling request (SR). Alternatively, the CRC may be generated together with the HARQ ACK / NACK and the scheduling request (SR), the CRC may not be generated for the periodic CSI report, or a separate CRC may be generated for the periodic CSI report.

12 shows uplink control information ( UCI ) According to the size of CRC  Some of the produce way Example  Indicates.

Basically, CRC can cause degradation in PUCCH performance itself. Accordingly, the present specification proposes to determine whether to generate a CRC according to the size of the payload transmitted through the PUCCH or the size of uplink control information (UCI) to which the CRC is applied. For example, suppose that a CRC is generated for uplink control information (UCI) including HARQ ACK / NACK. In this case, as shown in FIG. 12A, the CRC for HARQ ACK / NACK may be generated only when the number of bits of HARQ ACK / NACK exceeds 22 bits. Alternatively, the CRC for HARQ ACK / NACK may be generated only when the number of configured cells exceeds five.

More specifically, the size of the CRC may be determined using the size of the payload transmitted through the PUCCH or the size of the uplink control information (UCI) to which the CRC is applied as a parameter. That is, the size of the CRC may be variably determined according to the size of the payload transmitted through the PUCCH or the size of uplink control information (UCI) to which the CRC is applied. For example, the size of the CRC is set by a high layer, and as the size of the payload transmitted through the PUCCH or the size of the uplink control information (UCI) to which the CRC is applied increases, the size of the CRC is increased. It can also be considered to be larger. When the PUCCH is transmitted, the greater the CRC occupies in the payload transmitted through the PUCCH, the more deteriorated the performance of the PUCCH due to the CRC, and such performance degradation alleviates the advantages of using the CRC. On the other hand, the smaller the CRC occupies in the payload transmitted through the PUCCH during PUCCH transmission, the weaker the performance degradation due to the CRC, which can maximize the advantage of using the CRC.

More specifically, as shown in (b) of FIG. 12, when the size of the uplink control information (UCI) payload to which the CRC is applied exceeds 22 bits but is 32 bits or less, the size of the CRC Can be set to 1 bit (single parity). As shown in FIG. 12C, when the size of the uplink control information (UCI) payload to which the CRC is applied exceeds 32 bits but is less than 64 bits, the size of the CRC may be set to 4 bits. In addition, as shown in (d) of FIG. 12, when the size of the uplink control information (UCI) payload to which the CRC is applied exceeds 64 bits, the size of the CRC may be set to 8 bits. Alternatively, when the size of the uplink control information (UCI) payload to which the CRC is applied is 64 bits or less, the size of the CRC may be set to 8 bits. have. The above-described example is just one example, and the section setting based on the size of the uplink control information (UCI) payload to which the CRC is applied and the size of the CRC set in the corresponding section may be changed. Will be self explanatory.

The size of the HARQ ACK / NACK payload to which the CRC is applied and the size of the CRC may have a direct proportional relationship. That is, in order to increase the error correction capability, as the size of the HARQ ACK / NACK payload increases, the size of the CRC may also be increased.

On the contrary, the size of the HARQ ACK / NACK payload to which the CRC is applied and the size of the CRC may have an inverse relationship. That is, the HARQ ACK / NACK payload has no error, but in order to reduce the probability that an error occurs in the CRC itself, the size of the CRC may be set smaller as the size of the HARQ ACK / NACK payload increases.

If an error is detected by the CRC and information on all HARQ ACKs is processed as a NACK, an error amplification by the CRC may be expanded as the size of the HARQ ACK increases. In order to reduce this limit, the size of the CRC increases as the size of the HARQ ACK increases, but may be considered to decrease the size of the CRC when the size of the HARQ ACK increases above a predetermined threshold size. More specifically, HARQ ACK or uplink control information (UCI) is distinguished by a specific size (size), CC or CC group, and generates a CRC for each distinguished unit Can be.

In this case, the size of the CRC may be 0, and when the size of the CRC is 0, it may be interpreted as not generating the CRC. In addition, when uplink control information (UCI) is transmitted through a PUSCH rather than a PUCCH, the size of the CRC may be set to be the same as that of the PUCCH, or may be set independently of the PUCCH.

In addition, in generating the CRC, the reference for the size of the HARQ ACK / NACK payload may be any one of a configured cell, an activated cell, or a scheduled cell. This criterion may be the same as the criterion for determining the size of the CRC, and may be independent of the criterion for determining the size of the CRC. For example, the size of the HARQ ACK / NACK payload may be determined based on the scheduled cell, but the size of the CRC may be determined based on the activated cell or the configured cell.

If interleaving and / or scrambling is performed on uplink control information (UCI) to which CRC is applied, interleaving and / or uplink control information (UCI) to be applied to CRC is performed. Alternatively, scrambling may be performed first, and a CRC may be generated based on an uplink control information (UCI) payload on which interleaving and / or scrambling are performed. In this case, there is a benefit that the deinterleaving and / or descrambling operations can only be performed if no error is verified through the CRC. However, the present invention is not limited thereto, and a CRC may be generated based on an original uplink control information (UCI) payload in which interleaving and / or scrambling is not performed. In this case, interleaving and / or scrambling may be performed only for the uplink control information (UCI) payload excluding the CRC, and may be performed for the payload including both the uplink control information (UCI) and the CRC.

<CRC Transmission Method via PUCCH>

Basically, the CRC may be continuously arranged in the payload to which the CRC is applied, encoded through the same encoder, and then mapped and transmitted in the data region of the PUCCH. However, CRC for uplink control information (UCI) may be transmitted through RS modulation without performing channel coding. In this case, the reference signal modulation transmits data by mapping specific data to some DMRS symbols when a plurality of DMRSs exist in a slot, thereby comparing a DMRS including no data with a DMRS including data at a receiving end. That's how. For example, when the size of the CRC is 2 bits or less, the second DMRS symbol of each slot is used for data transmission. When the size of the CRC is larger than 2 bits, the resource block (RB) unit or subcarrier group unit is used. Reference signal modulation may be performed. In addition, when the PUCCH is configured with four resource blocks (RBs), two bits of information on the CRC may be transmitted in the second DMRS symbol of each resource block (RB).

13 shows an example of an arrangement order of uplink control information (UCI) and CRC.

Basically, in encoding and transmitting the CRC through the same encoder as the uplink control information (UCI), the position of the CRC may be basically located at the next position of the uplink control information (UCI). However, in this specification, as shown in FIG. 13, it is proposed to arrange the CRC at a position ahead of the uplink control information (UCI). In this case, the CRC is located on the tail bits side when encoding using a tail-bit convolutional code (TBCC) to avoid a situation in which an initial / final state is designated and the uplink control information ( Known bits located at the end of the UCI may serve as tail bits of the TBCC, thereby improving the performance of the TBCC.

<PUCCH CRC masking>

If the size of the CRC is more than the predetermined size, additional information may be transmitted through masking to the CRC. The following describes additional information that may be considered when CRC masking in generating a CRC for uplink control information (UCI).

1) The bundling scheme information for HARQ ACK / NACK or an indication of a set set in the RRC may be masked in the CRC. For example, when bundling is not performed, the CRC may be masked with an all-zero sequence, and when bundling, the CRC may be masked with an all-one sequence. .

2) An indicator of the size or configuration information of the HARQ ACK / NACK payload may be masked to the CRC. Specifically, a sequence used for masking may be differently applied according to the number of bits constituting the HARQ ACK / NACK payload or a cell group corresponding to the HARQ ACK / NACK feedback. The UE may dynamically determine a number of bits or a target cell group constituting the HARQ ACK / NACK payload based on a cell scheduled to the UE based on the masked sequence.

3) If the setting value for the periodic CSI report can be changed dynamically, after indicating some set in the information or RRC, an indicator indicating this can be masked and transmitted to the CRC.

4) The indicator for the cell or CSI procedure information that is subject to periodic CSI reporting may be masked to the CRC. In detail, a sequence used for masking may be differently applied according to a cell or a CSI process index that is a target of periodic CSI reporting. The UE may dynamically select and report a cell or CSI procedure index suitable for itself (having better channel quality) based on the masked sequence.

5) The indicator for the scheduling request (SR) information may be masked to the CRC. In detail, the UE may apply a sequence used for masking differently according to whether the scheduling request SR is positive or negative. In this case, a separate bit for the scheduling request (SR) indicator may not be configured on the PUCCH payload.

6) Before performing encoding on uplink control information (UCI), interleaving and / or scrambling may be performed on uplink control information (UCI). This is to prevent the performance of the CRC from dropping according to the position of the value or 0 of the uplink control information (UCI) sequence. In this case, the UE may interleave according to the information of the uplink control information (UCI) to be transmitted (for example, the size of the uplink control information (UCI), the value of the uplink control information (UCI), the location of a known bit, and the like). And / or otherwise apply scrambling, information related to the application of interleaving and / or scrambling (e.g. whether interleaving and / or scrambling is applied, what is interleaving and / or scrambling applied to, how it is applied, the applied interleaving pattern or the scrambling to be used) Sequence, etc.) can be masked and transmitted to the CRC. For example, when a plurality of interleaving patterns exist, an indicator for a pattern set by a higher layer or a preset pattern may be masked and transmitted to the CRC. In addition, the UE may prevent all outputs of the TBCC from being the same value through scrambling in order to improve TBCC performance when all HARQ ACK / NACK is ACK during HARQ ACK / NACK transmission.

The CRC masking methods as described above may be independently applied to each CRC when generating the CRC for each type of uplink control information (UCI).

Meanwhile, the next system considers a bit reverse order (BRO) form as an interleaving method. The BRO method expresses an input sequence index of an interleaver as a bit and sets the value expressed in decimal in the reverse order as an output sequence index. The size of the interleaver is 2 It can be expressed as an exponent of. For example, if the size of the interleaver is 8 bits, input sequence indexes 0 (000), 1 (001), 2 (010), 3 (011), 4 (100), 5 (101), and 6 (110). The output sequence index for, 7 (111) is 0 (000), 4 (100), 2 (010), 6 (110), 1 (001), 5 (101), 3 (011), 7 (111) Can be If it is assumed that the size of the uplink control information (UCI) is always an exponent of 2, additional processing for some bits may be required when the BRO interleaver is applied.

Basically, with respect to the size K of the uplink control information (UCI), the BRO interleaver may be configured based on the minimum value of the exponent values of 2 greater than K. Then, for the index exceeding the size K of the uplink control information (UCI), the method ignores the corresponding position and writes the next output index, or replaces the position with a known bit and writes the next output index, or uplink control. One of the methods of restricting the size K of the information UCI to be an exponential form of 2 may be applied. For example, when the size of the uplink control information (UCI) is 5, the size of the BRO interleaver is 8, according to the first of the above-described schemes are interleaved in the form of 0, 4, 2, 1, 3, According to the second scheme, interleaving may be performed in the form of 0, 4, 2, known bits, 1, known bits, 3, and known bits.

Alternatively, for the size K of the uplink control information UCI, the BRO interleaver may be configured based on a maximum value of two exponent values smaller than K, and interleaving may be performed on some input bits. More specifically, in order to improve the performance of the TBCC, interleaving may be performed to perform only a low bit index or a high bit index portion so that the last or first bits may be set to known bits. Here, setting from the last bit to the well-known bit (i.e., performing only the interleaved low bit index portion) compensates for the performance degradation caused by the lack of tail bits in the TBCC (compared to typical terminated convolutional code with tail bits). To do this. In this case, for example, when the size of the uplink control information (UCI) is 5 as described above, the size of the BRO interleaver is 4 bits and may be interleaved in the form of 0, 2, 1, 3, and 4.

As another method, the interleaving pattern may be changed according to the size of uplink control information (UCI) based on the configured serving cell. For example, consider sorting by selecting X bits at the beginning of the input sequence and X bits at the end. Here, the X bit may be 1 bit. More specifically, when the size of the uplink control information (UCI) is 8, interleaving may be performed in the form of 0, 7, 1, 6, 2, 5, 3, and 4. In other words, if the input sequence b (i), i = 0, 1, 2,?, K-1, and the output sequence c (i), i = 0, 1, 2,?, K-1, It can be represented by the following equation.

Where K is odd,

Will not count.

14 is uplink control information according to the present specification ( UCI ) Indicating the transmission method It is a flowchart .

Referring to FIG. 14, in a carrier aggregation (CA) environment in which five or more carriers are aggregated, the UE may transmit uplink control information (UCI) and CRC for error detection of uplink control information together through a PUCCH.

More specifically, the UE determines whether to generate a CRC based on the size of uplink control information (UCI) (S100). If the UE determines to generate the CRC, the UE may variably determine the size of the CRC to be generated based on the size of the uplink control information (UCI). In addition, the UE determines the size of the CRC such that the size of the CRC increases as the size of the uplink control information (UCI) increases, but uplink control information when the size of the uplink control information (UCI) is greater than or equal to a preset threshold size. As the size of the UCI increases, the size of the CRC may be determined to be smaller.

In addition, when the uplink control information (UCI) includes HARQ ACK / NACK and periodic CSI reporting, the UE may generate a single CRC for the HARQ ACK / NACK and periodic CSI reporting. Furthermore, when a plurality of pieces of information are transmitted through the uplink control information (UCI), the UE may generate a CRC only for information having a degree of importance or more than a critical importance among the plurality of pieces of information.

If the UE determines to generate a CRC, the UE generates a CRC for error detection of uplink control information (UCI) (S200). Here, when interleaving or scrambling is performed on the uplink control information (UCI), the UE may generate a CRC based on the payload of the uplink control information (UCI) after the interleaving or scrambling is performed.

The UE maps the generated CRC and uplink control information (UCI) to the PUCCH (S300). Here, the UE may map the CRC and the uplink control information (UCI) so that the CRC may be disposed at a position preceding the uplink control information (UCI).

Meanwhile, the UE may mask the additional information sequence in the CRC. Here, the additional information sequence may include any one of information on bundling of HARQ ACK / NACK, information on setting values of periodic CSI reporting, information on scheduling request (SR), and information on whether interleaving or scrambling is applied. It may be, but is not limited thereto. If the additional information sequence includes information on whether interleaving or scrambling is applied, the additional information sequence may further include information on an application target of interleaving or scrambling, an applied interleaving pattern, or a scrambling sequence.

The UE transmits the PUCCH to which the CRC and the uplink control information (UCI) are mapped (S400).

15 illustrates a wireless communication system in which the present disclosure is implemented. Block diagram .

The base station 200 includes a processor 201, a memory 202, and an RF unit 203. The memory 202 is connected to the processor 201 and stores various information for driving the processor 201. The RF unit 203 is connected to the processor 201 to transmit and / or receive a radio signal. The processor 201 implements the proposed functions, processes and / or methods. In the above-described embodiment, the operation of the base station may be implemented by the processor 201.

The UE 100 includes a processor 101, a memory 102, and an RF unit 103. The memory 102 is connected to the processor 101 and stores various information for driving the processor 101. The RF unit 103 is connected to the processor 101 and transmits and / or receives a radio signal. The processor 101 implements the proposed functions, processes and / or methods.

The processor may include application-specific integrated circuits (ASICs), other chipsets, logic circuits, and / or data processing devices. The memory may include read-only memory (ROM), random access memory (RAM), flash memory, memory card, storage medium and / or other storage device. The RF unit may include a baseband circuit for processing a radio signal. When the embodiment is implemented in software, the above-described technique may be implemented as a module (process, function, etc.) for performing the above-described function. The module may be stored in memory and executed by a processor. The memory may be internal or external to the processor and may be coupled to the processor by various well known means.

In the exemplary system described above, the methods are described based on a flowchart as a series of steps or blocks, but the invention is not limited to the order of steps, and certain steps may occur in a different order or concurrently with other steps than those described above. Can be. In addition, those skilled in the art will appreciate that the steps shown in the flowcharts are not exclusive and that other steps may be included or one or more steps in the flowcharts may be deleted without affecting the scope of the present invention.

Claims (15)

1. In a carrier aggregation (CA) environment that aggregates five or more carriers, a user equipment transmits uplink control information (UCI) through a physical uplink control channel (PUCCH) As a way to,

   Determining whether to generate a Cyclic Redundancy Check (CRC) based on the size of the uplink control information (UCI);

   Generating a CRC for error detection of the uplink control information (UCI) when determining to generate the CRC;

   Mapping the generated CRC and the uplink control information (UCI) to the PUCCH; And

   And transmitting the PUCCH to which the CRC and the uplink control information are mapped.
2. The method of claim 1, wherein determining whether to generate the CRC

   And a method of flexibly determining a size of a CRC to be generated based on a size of the uplink control information (UCI).
3. The method of claim 2, wherein determining whether to generate the CRC

   The size of the CRC is determined so that the size of the CRC increases as the size of the uplink control information UCI increases, but when the size of the uplink control information UCI is greater than or equal to a preset threshold size, the uplink control And determining the size of the CRC so that the size of the CRC decreases as the size of the information UCI increases.
4. The method of claim 1, wherein determining whether to generate the CRC

   If the UL control information (UCI) includes HARQ (Hybrid Automatic Repeat reQuest) HARQ ACK (Non-ACKnowledgement) / NACK (Non-ACKnowledgement) and periodic CSI report (periodic Channel State Information report), the HARQ ACK / NACK and And generating a single CRC for periodic CSI reporting.
5. The method of claim 1, wherein determining whether to generate the CRC

   When a plurality of pieces of information are transmitted through the uplink control information (UCI), generating a CRC only for information having a greater than or equal to a critical importance among the plurality of pieces of information.
6. The method of claim 1, wherein generating the CRC

   When interleaving or scrambling is performed on the uplink control information UCI, the payload of uplink control information UCI after the interleaving or scrambling is performed. Uplink control information transmission method, characterized in that for generating a CRC.
7. The method of claim 1, wherein the mapping of the CRC and uplink control information (UCI)

   And mapping the CRC and uplink control information (UCI) so that the CRC can be located at a position preceding the uplink control information (UCI).
8. According to claim 1,

   Masking a sequence of additional information in the CRC;

   The additional information sequence includes information on bundling HARQ ACK / NACK, information on a setting value of a periodic CSI report, information on a scheduling request (SR), and information on whether interleaving or scrambling is applied. Uplink control information transmission method, characterized in that it comprises any one.
9. The method of claim 8,

   When the additional information sequence includes information on whether interleaving or scrambling is applied, the additional information sequence further includes information on an application target of the interleaving or scrambling, an applied interleaving pattern, or a scrambling sequence. Uplink control information transmission method.
10. A wireless device for transmitting uplink control information (UCI) through a physical uplink control channel (PUCCH) in a carrier aggregation (CA) environment that aggregates five or more carriers,

    RF (Radio Frequency) unit;

    And a processor for controlling the RF unit, wherein the processor

    Determining whether to generate a CRC based on the size of the uplink control information (UCI);

    Generating a CRC for error detection of the uplink control information (UCI) when determining to generate the CRC;

    Mapping the generated CRC and the uplink control information (UCI) to the PUCCH; And

    And transmitting a PUCCH to which the CRC and uplink control information are mapped.
11. The method of claim 10, wherein the processor is

    And flexibly determining a size of a CRC to be generated based on the size of the uplink control information (UCI).
12. 12. The system of claim 11, wherein the processor is

    The size of the CRC is determined so that the size of the CRC increases as the size of the uplink control information UCI increases, but when the size of the uplink control information UCI is greater than or equal to a preset threshold size, the uplink control And determining the size of the CRC such that the size of the information (UCI) increases as the size of the CRC decreases.
13. The method of claim 10, wherein the processor is

    If the uplink control information (UCI) includes the HARQ ACK / NACK and the periodic CSI report, characterized in that for generating a single CRC for the HARQ ACK / NACK and the periodic CSI report.
14. The method of claim 10, wherein the processor is

    And when a plurality of pieces of information are transmitted through the uplink control information (UCI), generating a CRC only for information having a greater than or equal to a critical importance among the plurality of pieces of information.
15. The method of claim 10, wherein the processor is

    And mapping the CRC and uplink control information (UCI) so that the CRC can be located at a position ahead of the uplink control information (UCI).

Images