KR20150074831A - Method and apparatus for transmitting control information for mtc - Google Patents

Abstract

The specification relates to a method and a device for transmitting control information for machine-type communication (MTC) user equipment (UE) in a wireless communication system. The method comprises the steps of: determining the number of orthogonal frequency division multiplexing (OFDM) symbols used in transmitting a physical downlink control channel (PDCCH), based on physical hybrid ARQ indicator channel (PHICH) duration; generating PHICH constitution information for directing the PHICH duration and the number of OFDM symbols; and transmitting a physical broadcasting channel (PBCH) including the PHICH constitution information to the MTC UE. When the PHICH duration is normal PHICH duration and the number of total downward link resource blocks is 10 or less, and the number of OFDM symbols is 2.

Description

TECHNICAL FIELD The present invention relates to a method and apparatus for transmitting control information for MTC (Machine-Type Communication)

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to wireless communication, and more particularly, to a method and apparatus for transmitting control information for MTC.

Machine-type communication (MTC) is a form of data communication that involves one or more entities that do not require human interaction. That is, the MTC refers to a concept that a machine other than a user equipment (UE) used by a human user communicates using an existing wireless communication network. The terminal used in the MTC may be called an MTC terminal (MTC UE), and may be a machine for measuring the level of a dam, a vending machine for an MTC UE, and the like.

Since the characteristics of an MTC UE are different from those of a general terminal, a service optimized for MTC communication may be different from a service optimized for human-to-human communication. The MTC is based on different market scenarios, data communication, low cost and effort, potentially a very large number of MTC UEs, a large service area and low traffic per MTC UE, compared to current mobile network communication services. Can be characterized. According to this feature, the signaling overhead for the MTC UE may cause degradation of system performance. Thus, a method is needed that can reduce the signaling overhead for the MTE UE.

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and it is an object of the present invention to provide control information for a MTC, in particular, a CFI (Control Format Indicator)

Another object of the present invention is to provide a CFI configuration method and apparatus for MTC that can prevent waste of radio resources.

According to an aspect of the present invention, a method of transmitting control information for a MTC (Machine-Type Communication) user equipment (UE) in a wireless communication system is provided. The method of transmitting control information includes determining the number of orthogonal frequency division multiplexing (OFDM) symbols used for transmission of a Physical Downlink Control Channel (PDCCH) based on a PHICH (Physical Hybrid ARQ Indicator Channel) , Generating PHICH configuration information indicating the PHICH period and the number of OFDM symbols, and transmitting a PBCH (Physical Broadcasting Channel) including the PHICH configuration information to the MTC UE, wherein the PHICH period is A normal PHICH period, and the number of OFDM symbols is 2 when the total number of downlink resource blocks is 10 or less.

According to another aspect of the present invention, when the PHICH period is a general PHICH period and the total number of downlink resource blocks exceeds 10, a carrier configured with four cell-specific antenna ports and supporting a PDSCH In the MBSFN subframe on the uplink, the number of OFDM symbols may be implemented to be two.

According to another aspect of the present invention, when the PHICH period is an extended PHICH period and the total number of downlink resource blocks is 10 or less, a subframe of a TDD (Time Division Duplex) of a non-MBSFN (non-MBSFN) If the frame is not a frame 1 and a frame 6 but is not a subframe composed of PRS, the number of OFDM symbols may be 4.

According to another aspect of the present invention, a method for receiving control information by a MTC (Machine-Type Communication) user equipment (UE) in a wireless communication system is provided. The method includes receiving a Physical Broadcast Channel (PBCH) including PHICH (Physical Hybrid ARQ Indicator Channel) configuration information from a base station, receiving a PHICH period and a PDCCH (Physical Downlink Control Channel) indicated by the PHICH configuration information, Receiving a PHICH and a PDCCH from the base station based on a number of Orthogonal Frequency Division Multiplexing (OFDM) symbols used for transmission of the total downlink resource block, wherein the PHICH period is a normal PHICH period, When the number of OFDM symbols is 10 or less, the number of OFDM symbols may be 2.

According to another aspect of the present invention, when the PHICH period is a general PHICH period and the total number of downlink resource blocks exceeds 10, the PDCCH is configured with four cell-specific antenna ports, In the MBSFN subframe on the carrier, the number of OFDM symbols may be implemented to be two.

According to another aspect of the present invention, when the PHICH period is an extended PHICH period and the total number of downlink resource blocks is 10 or less, a subframe of a TDD (Time Division Duplex) of a non-MBSFN (non-MBSFN) If the frame is not a frame 1 and a frame 6 but is not a subframe composed of PRS, the number of OFDM symbols may be 4.

According to another aspect of the present invention, an apparatus for transmitting control information for a MTC (Machine-Type Communication) user equipment (UE) in a wireless communication system is provided. The control information transmission apparatus includes an OFDM symbol for determining the number of Orthogonal Frequency Division Multiplexing (OFDM) symbols used for transmission of a Physical Downlink Control Channel (PDCCH) based on a PHICH (Physical Hybrid ARQ Indicator Channel) A PHICH configuration information generation unit for generating PHICH configuration information indicating the number of PHICH periods and the number of OFDM symbols, and a transmission unit for transmitting a PBCH (Physical Broadcasting Channel) including the PHICH configuration information to the MTC UE Wherein the number of the OFDM symbols is 2 when the PHICH period is a normal PHICH period and the total number of downlink resource blocks is 10 or less.

According to another aspect of the present invention, when the PHICH period is a general PHICH period and the total number of downlink resource blocks exceeds 10, the PDCCH is configured with four cell-specific antenna ports, In the MBSFN subframe on the carrier, the number of OFDM symbols may be implemented to be two.

According to another aspect of the present invention, when the PHICH period is an extended PHICH period and the total number of downlink resource blocks is 10 or less, a subframe of a TDD (Time Division Duplex) of a non-MBSFN (non-MBSFN) If the frame is not a frame 1 and a frame 6 but is not a subframe composed of PRS, the number of OFDM symbols may be 4.

According to another aspect of the present invention, there is provided an apparatus for receiving control information by a MTC (machine-type communication) user equipment (UE) in a wireless communication system, the apparatus comprising: a PBCH (Physical Hybrid ARQ Indicator Channel) Based on a PHICH period indicated by the PHICH configuration information and a number of Orthogonal Frequency Division Multiplexing (OFDM) symbols used for transmission of a Physical Downlink Control Channel (PDCCH) The number of the OFDM symbols is 2 when the PHICH period is a normal PHICH period and the total number of downlink resource blocks is 10 or less.

According to another aspect of the present invention, when the PHICH period is a general PHICH period and the total number of downlink resource blocks exceeds 10, the PDCCH is configured with four cell-specific antenna ports, In the MBSFN subframe on the carrier, the number of OFDM symbols may be implemented to be two.

According to another aspect of the present invention, when the PHICH period is an extended PHICH period and the total number of downlink resource blocks is 10 or less, a subframe of a TDD (Time Division Duplex) of a non-MBSFN (non-MBSFN) If the frame is not a frame 1 and a frame 6 but is not a subframe composed of PRS, the number of OFDM symbols may be 4.

According to the present invention, the number of orthogonal frequency division multiplexing (OFDM) symbols used for transmission of a physical downlink control channel (PDCCH) can be informed without separate control format indicator (CFI) signaling for the MTC UE. In addition, the limitation of the number of OFDM symbols for PDCCH transmission is relaxed, and waste of radio resources can be prevented.

1 shows an example of MTC (Machine-Type Communication) to which the present invention is applied.
2 shows a flow of a control information transmission method for an MTC according to the present invention.
3 shows a flow of a control information receiving method for an MTC according to the present invention.
4 is a data flow diagram of control information for the MTC according to the present invention.
5 is a block diagram illustrating a terminal receiving control information for the MTC and a base station transmitting control information for the MTC according to 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 shows an example of MTC (Machine-Type Communication) to which the present invention is applied.

MTC (Machine-Type Communication) is also referred to as M2M (Machine-to-Machine Communication), and is an information exchange between MTC UEs 11 and 12 via a base station 15 not involving human interaction, And refers to information exchange between the MTC UE 11 and the MTC server 18. [

The MTC server 18 is an entity communicating with the MTC UE 11. The MTC server executes the MTC application and provides the MTC UE 11 with the MTC specific service.

The MTC UE 11 is a wireless device that provides MTC, and may be fixed or mobile. The MTC UE is also referred to as an M2M UE.

MTC can be a major source of revenue for operators and has huge potential in terms of operators. A new MTC access technology is under development to operate efficient M2M (Machine to Machine) systems with fewer people. However, it is more efficient for service providers to provide services to MTC UEs by utilizing already developed wireless access technologies. Therefore, it is important for carriers to understand how Long Term Evolution (LTE) is a competitive wireless access technology to efficiently support MTC. The MTC UE may use a number of MTC UEs sufficient to build its own eco-system. Reducing the cost of an MTC UE is an important driving force for implementing the concept of "the Internet of things".

MTC UEs used in many applications require low operating power consumption and can communicate with intermittent and small burst transmissions.

In addition, since MTC devices are used substantially inside a deep building, it is required that the coverage be improved over the conventional LTE cell coverage range.

The concept and cost analysis for providing a low cost MTC UE can be described. The criteria for cost analysis is a single band, a single Radio Access Technology (RAT), and one UE within a bandwidth category of 20 MHz. Concepts for providing low cost MTC UEs include:

- Reduced maximum bandwidth

- Single receive RF chain

- Reduced maximum speed

- Reduced transmit power

- Half duplex operation

- Reduced Supported Downlink Transmission Modes

The maximum bandwidth supported by a typical LTE UE is 20 MHz. One way to reduce UE cost is to lower the maximum bandwidth supported by the UE at 20 MHz (e.g., 1.4 MHz, 3 MHz, or 5 MHz). The maximum bandwidth reduction may be applied to the downlink and / or uplink, the RF and / or baseband component, the data and / or the control channel. More specifically, the following options for downlink (DL) and uplink (UL) may be considered as a method for reducing the bandwidth.

- The downlink (DL)

Option DL-1: Bandwidth reduction of RF and baseband

Option DL-2: Bandwidth reduction for baseband for data and control channels

Option DL-3: Bandwidth reduction of the data channel in baseband while the control channel is allowed to be used for carrier bandwidth

- The uplink (UE)

Option UL-1: Bandwidth reduction for RF and baseband

Option UL-2: No reduction in bandwidth (this option has no impact on coverage, power consumption, specifications, performance, or UE cost)

These options assume that the reduced bandwidth can not be lower than 1.4 MHz, and the position of the reduced bandwidth frequency is assumed to be fixed at the center of the carrier bandwidth. The options of the downlink and uplink may be combined. In addition, the methods for reducing the bandwidth are not limited to the above options, and may be variously modified. For example, the option DL-3 can be extended as follows.

- If the frequency location of the data channel is set semi-statically, it may be expected that the same cost savings as DL-3 will be provided due to the effect of some additions.

- If the frequency position of the data channel is allowed to change dynamically, it will be equal to one of the techniques for a reduced peak rate that limits the number of PRBs (Physical Resource Blocks).

The cost savings and the impact of the specification may vary depending on the option. Also, when the maximum bandwidth is reduced, degradation of coverage may occur as compared to the normal LTE UEs as follows.

One) Downlink

- PDSCH: In the case of options DL-1, DL-2, and DL-3, PDSCH coverage may be affected due to loss of frequency selective scheduling gain.

- Downlink control channel (PCFICH / PHICH / PDCCH):

Performance of the Physical Control Format Indicator Channel (PCFICH), the Physical Hybrid-ARQ Indicator Channel (PHICH), and the PDCCH are expected to be degraded due to the loss due to the frequency diversity in the options DL-1 and DL-2 . The degree of degradation, or degradation, of coverage is determined by which solution is adopted for the PCFICH / PHICH / PDCCH within the reduced bandwidth. A new PCFICH / PHICH / PDCCH design can be considered to improve coverage.

In the case of option DL-3, no loss due to frequency diversity occurs because the PCFICH / PHICH / PDCCH is still transmitted along the carrier bandwidth. If the CRS (Cell-specific Reference Signal) is processed in the entire carrier bandwidth as currently performed, the performance of the PCFICH / PHICH / PDCCH will be maintained. However, if the CRS is processed within the narrowband of the PDSCH region where channel estimation errors occur more frequently, it may affect coverage.

2) Uplink (only for option UL-1)

- The coverage of the PUCCH is even smaller due to loss of frequency diversity.

- The coverage of the PUCCH may be further reduced due to loss in frequency hopping gain or frequency selective scheduling gain.

- The coverage of the PRACH is not affected.

The Physical Control Format Indicator Channel (PCFICH) carries a CFI (Control Format Indicator), which is information on the number of OFDM symbols used for transmission of the PDCCH in a subframe. Table 1 shows the number of OFDM symbols usable for the PDCCH in one subframe.

Subframe

일 때, PDCCH를 위한 OFDM 심볼의 수

, The number of OFDM symbols for the PDCCH

, The number of OFDM symbols for the PDCCH In frame structure type 2, subframes 1 and 6 1, 2 2 One or two cell-specific antenna ports, and the MBSFN subframe on the carrier supporting the PDSCH, 1, 2 2 (MBSFN) subframe on a carrier that is configured with four cell-specific antenna ports and supports the PDSCH, 2 2 Frame on a carrier that does not support PDSCH 0 0 (Non-MBSFN) subframe (excluding subframe 6 in frame structure type 2) composed of PRS (positioning reference signal) 1, 2, 3 2, 3 In all other cases 1, 2, 3 2, 3, 4

The PCFICH may be sent to the UE if the number of OFDM symbols for the PDCCH is greater than zero.

In the present invention, the respective conditions of the subframe in Table 1 are defined as follows.

Case 1: Frame Structure In Type 2, subframes 1 and 6

Case 2: One or two cell-specific antenna ports, and the MBSFN subframe on the carrier supporting the PDSCH

Case 3: MBSFN subframe on a carrier that is composed of four cell-specific antenna ports and supports PDSCH

Case 4: Non-MBSFN (non-MBSFN) subframe composed of PRS (excluding subframe 6 in frame structure type 2)

Case 5: All other cases

The PHICH (Physical Hybrid ARQ Indicator Channel) duration can be set by an upper layer as shown in Table 2.

PHICH cycle Non-MBSFN subframe MBSFN sub-frame on carrier supporting PDSCH Subframes 1, 6 in frame structure type 2 In all other cases Normal One One One Extended (extended) 2 3 2

Referring to Table 2, in the case of the MBSFN subframe on the carrier supporting the PDSCH and in the case of the subframes 1 and 6 in the non-MBSFN subframe and the frame structure type 2 (i.e., TDD (Time Division Duplex) Is an OFDM symbol and the extended PHICH period is two OFDM symbols. In other cases, the generic PHICH period is one OFDM symbol and the extended PHICH period is three OFDM symbols.

As mentioned above, in a reduced bandwidth for a low-cost enhanced coverage MTC UE, the performance of the PCFICH may be degraded due to loss due to frequency diversity. In the conventional bandwidth, PCFICH exists as a frequency axis at each position where the total system bandwidth is divided into four quadrants. However, in the case of the options DL-1 and DL-2 mentioned above, since the bandwidth for the MTC UE is reduced as compared with the system bandwidth, a loss occurs in some of the four frequency diversities. If a repetition of PCFICH is applied to improve coverage (e.g., on the time axis), the flexibility of the CFI indication in each subframe is reduced or the downlink spectrum efficiency is reduced.

Therefore, a new mechanism for removing the existing PCFICH and indicating the CFI value for the MTC UE can be considered. The following methods can be considered for this purpose.

(Method 1) Fixed CFI value

The CFI value may be defined as a fixed value (e.g., CFI = 2 or CFI = 3) fixed between the MTC UE and the base station (eNodeB). By a fixed CFI value, the normal UE and the MTC UEs can be scheduled by the eNodeB. However, in this case, the flexibility of the CFI of common UEs may be limited.

(Method 2) Directed through PBCH (Physical Broadcasting Channel)

The CFI value may be indicated to the MTC UE over the PBCH using the PHICH period. However, in this case, the flexibility of the CFIs of the normal UEs other than the MTC UEs may be affected if a normal PHICH duration is used.

Method 1 and Method 2 remove the PCFICH for MTC UEs and replace the CFI indicated by the PCFICH, which includes information on the number of OFDM symbols used for transmission of the PDCCH in the subframe, These are the methods that can be considered to construct.

However, in the case of the method 1, since only one CFI value fixed for the MTC UEs is used, there may be a serious limitation on the CFI value configuration of the general UEs as well as the MTC UEs. In general, the number of OFDM symbols used for transmission of a PDCCH in a subframe can be determined according to the number of scheduled UEs and accordingly the amount of PDCCH required. The number of OFDM symbols may have a value of 1 to 4. However, fixed CFI values have limited flexibility. For example, when the CFI value is fixed to a high value (for example, 3), if the number of scheduled UEs and the amount of PDCCH configured accordingly is small, the OFDM symbol allocated to the PDCCH is unnecessary. The downlink spectrum efficiency is reduced due to waste of radio resources. Conversely, if the CFI value is fixed to a low value (for example, 1), the number of UEs to be scheduled and the amount of PDCCHs constituted thereby are large, the number of OFDM symbols that can be allocated to the PDCCH is limited, Is severely limited.

On the other hand, in the case of the method 2, two CFI values can be used according to the PHICH duration, so that the CFI configuration can be more flexible than the method 1. In other words, referring to Table 2, the CFI value of the normal PHICH period is 1, the MBSFN subframe on the carrier supporting the PDSCH and the non-MBSFN (non-MBSFN) subframe in the case of the extended PHICH period In subframes 1 and 6 of TDD, the CFI value is 2, and in other cases, the CFI value is 3. However, when setting the CFI value directly in conjunction with the PHICH period, the following issues may exist.

일 때의 케이스 3 및

일때의 케이스 1 내지 케이스 5): 방법 2에 의해서 일반(normal) PHICH 주기에서는 CFI가 1로 지시되는데 반해, 표 1의 PCFICH에 의하면 CFI 값이 1을 지원하지 않기 때문에, 서로 상반된다.1) If the CFI value indicated by PCFICH in Table 1 can not be 1 (

Case 3 < / RTI >

Case 1 to Case 5): According to the method 2, CFI is indicated as 1 in a normal PHICH cycle, whereas PCIICH in Table 1 does not support a CFI value.

일 때의 케이스 5): 방법 2에 의해서 확장(extended) PHICH 주기에서는 CFI가 3으로 지시되는데 반해, 표 1의 PCFICH에 의하면 CFI는 최대 4까지 지시될 수 있기 때문에, 서로 상반된다.2) When the CFI value indicated by the PCFICH in Table 1 is 4

Case 5): In Method 2, the CFI is indicated as 3 in the extended PHICH cycle, whereas the CFI in the PCFICH in Table 1 is inconsistent as it can be indicated up to 4.

Therefore, in order to solve the problems of the method 1 and the method 2, it is preferable that the CFI is defined or configured so as not to be incompatible with the PHICH period. Therefore, this embodiment indicates the CFI for the MTC UEs using the PHICH period as in the method 2, but instead of directly associating with the PHICH period, the two PHICH periods ( For example, a normal PHICH period, an extended PHICH period) to indicate a specific CFI value optimized.

In the following embodiment, a CFI value used for MTC UEs in a general PHICH cycle is defined as A, and a CFI value used for MTC UEs in an extended PHICH cycle is defined as B. For example, if the CFI value is set in the PHICH period of method 2, then A is always 1 and B is a subframe 1 of the TDD among the MBSFN subframe on the carrier supporting the PDSCH and the non-MBSFN (non-MBSFN) And 2 in the case of 6 and 3 in other cases. However, if the A and B values are directly related to the PHICH period, the same problem as described above may occur. Therefore, in the present invention, an example in which the specific CFI values A and B optimized by using the two PHICH periods (general PHICH period, extended PHICH period) according to the respective conditions of the subframe in Table 1 will be described .

For example, according to this embodiment, the CFI values A and B constructed (or defined) using the PHICH period are as shown in Table 3 or Table 4.

Subframe

일 때, PDCCH를 위한 OFDM 심볼의 수

, The number of OFDM symbols for the PDCCH

, The number of OFDM symbols for the PDCCH Normal PHICH duration Extended (extended)
PHICH duration Normal PHICH duration Extended (extended)
PHICH duration In frame structure type 2, subframes 1 and 6 One 2 2 2 One or two cell-specific antenna ports, and the MBSFN subframe on the carrier supporting the PDSCH, One 2 2 2 (MBSFN) subframe on a carrier that is configured with four cell-specific antenna ports and supports the PDSCH, 2 2 2 2 Frame on a carrier that does not support PDSCH 0 0 0 0 (Non-MBSFN) subframe (excluding subframe 6 in frame structure type 2) composed of PRS (positioning reference signal) One 3 2 3 In all other cases One 3 2 4

Subframe

일 때, PDCCH를 위한 OFDM 심볼의 수

, The number of OFDM symbols for the PDCCH

, The number of OFDM symbols for the PDCCH Normal PHICH duration Extended (extended)
PHICH duration Normal PHICH duration Extended (extended)
PHICH duration In frame structure type 2, subframes 1 and 6 One 2 2 2 One or two cell-specific antenna ports, and the MBSFN subframe on the carrier supporting the PDSCH, One 2 2 2 (MBSFN) subframe on a carrier that is configured with four cell-specific antenna ports and supports the PDSCH, 2 2 2 2 Frame on a carrier that does not support PDSCH 0 0 0 0 (Non-MBSFN) subframe (excluding subframe 6 in frame structure type 2) composed of PRS (positioning reference signal) 2 3 2 3 In all other cases 2 3 2 4

Referring to Table 3 and Table 4, A and B are as follows.

일 때:

when:

1) Case 1 (in frame structure type 2, subframes 1 and 6): A = 1, B = 2

2) Case 2 (MBSFN subframe on a carrier that is composed of one or two cell-specific antenna ports and supports PDSCH): A = 1, B = 2

3) Case 3 (MBSFN subframe on a carrier that is composed of four cell-specific antenna ports and supports PDSCH): A = 2, B = 2

4) Case 4 (non-MBSFN) sub-frame (except subframe 6 in frame structure type 2) composed of PRS: A = 1 (or A = 2), B = 3

5) Case 5 (all other cases): A = 1 (or A = 2), B = 3

일 때:

when:

1) Case 1 (in frame structure type 2, subframes 1 and 6): A = 2, B = 2

2) Case 2 (MBSFN subframe on a carrier that consists of one or two cell-specific antenna ports and supports PDSCH): A = 2, B = 2

3) Case 3 (MBSFN subframe on carrier with PDSCH support, consisting of 4 cell-specific antenna ports): A = 2, B = 2

4) Case 4 (non-MBSFN) sub-frame (excluding sub-frame 6 in frame structure type 2) composed of PRS: A = 2, B = 3

5) Case 5 (all other cases): A = 2 (or A = 3), B = 4

2 shows a flow of a control information transmission method for an MTC according to the present invention.

Referring to FIG. 2, the base station determines the number of OFDM symbols for configuring the PDCCH based on the period of the PHICH (S210). Here, if the period of the PHICH is a general PHICH period, the number of OFDM symbols for constructing the PDCCH is A. If the period of the PHICH is the extended PHICH period, the number of OFDM symbols for constructing the PDCCH is B; Here, the values of A and B can be defined according to the embodiments of Tables 3 and 4 above. In determining the number of OFDM symbols for constructing the PDCCH, not only the period of the PHICH but also the number of downlink resource blocks (N ^DL _RB ) and the type of subframe can be considered together (see Tables 3 and 4) Reference).

The base station generates PHICH configuration information indicating the number of OFDM symbols and the PHICH period for configuring the PDCCH determined in step S210 (S230). The PHICH configuration information can be defined as shown in the following table.

- ASN1START PHICH-Config :: = SEQUENCE { phich-Duration ENUMERATED {normal, extended}, phich-Resource ENUMERATED {oneSixth, half, one, two} } - ASN1STOP

Referring to Table 5, the phich-Duration field (PHICH period) can indicate normal or extended, and the phich-Resource field has a value of 1/6, 1/2, 1, .

Then, a PBCH (Physical Broadcasting Channel) including the PHICH configuration information is transmitted to the terminal (S250). The base station may configure the PHICH and the PDCCH based on the PHICH configuration information and the number of OFDM symbols for configuring the PDCCH determined in step S210, and transmit the PHICH and the PDCCH to the mobile station in step S270.

3 shows a flow of a control information receiving method for an MTC according to the present invention.

Referring to FIG. 3, the UE receives a Physical Broadcast Channel (PBCH) including PHICH configuration information from a base station (S310). PHICH configuration information can be defined as shown in Table 5. The UE receives the PHICH and the PDCCH from the base station based on the PHICH period indicated by the PHICH configuration information and the number of OFDM symbols used for transmission of a Physical Downlink Control Channel (PDCCH) ).

4 is a data flow diagram of control information for the MTC according to the present invention.

The base station determines the number of OFDM symbols for configuring the PDCCH based on the period of the PHICH (S410). Here, if the period of the PHICH is a general PHICH period, the number of OFDM symbols for constructing the PDCCH is A. If the period of the PHICH is the extended PHICH period, the number of OFDM symbols for constructing the PDCCH is B; Here, the values of A and B can be defined according to the embodiments of Tables 3 and 4 above. In determining the number of OFDM symbols for constructing the PDCCH, not only the period of the PHICH but also the number of downlink resource blocks (N ^DL _RB ) and the type of subframe can be considered together (see Tables 3 and 4) Reference).

The base station generates PHICH configuration information indicating the number of OFDM symbols and the PHICH period for configuring the PDCCH determined in step S410 (S420). PHICH configuration information can be defined as shown in Table 5.

Then, the PBCH (Physical Broadcasting Channel) including the PHICH configuration information is transmitted to the MS (S430). The base station may configure the PHICH and the PDCCH based on the PHICH configuration information and the number of OFDM symbols for configuring the PDCCH determined in step S410 and transmit the PHICH and the PDCCH to the mobile station in step S440.

5 is a block diagram illustrating a terminal receiving control information for the MTC and a base station transmitting control information for the MTC according to the present invention.

Referring to FIG. 5, the terminal 500 includes a receiving unit 505 and a transmitting unit 520. The receiving unit 505 receives PBCH, PHICH, and PDCCH from the base station. The PBCH includes PHICH configuration information. PHICH configuration information can be defined as shown in Table 5. PHICH and PDCCH are received based on the PHICH period indicated by the PHICH configuration information and the number of Orthogonal Frequency Division Multiplexing (OFDM) symbols used for transmission of Physical Downlink Control Channel (PDCCH). The transmitting unit 520 transmits the uplink signal to the base station.

The base station 550 includes an OFDM symbol number determination unit 555, a PHICH configuration information generation unit 560, a transmission unit 565, and a reception unit 570.

The OFDM symbol number determination unit 555 determines the number of OFDM symbols for configuring the PDCCH based on the period of the PHICH. Here, if the period of the PHICH is a general PHICH period, the number of OFDM symbols for constructing the PDCCH is A. If the period of the PHICH is the extended PHICH period, the number of OFDM symbols for constructing the PDCCH is B; Here, the values of A and B can be defined according to the embodiments of Tables 3 and 4 above. In determining the number of OFDM symbols for constructing the PDCCH, not only the period of the PHICH but also the number of downlink resource blocks (N ^DL _RB ) and the type of subframe can be considered together (see Tables 3 and 4) Reference).

The PHICH configuration information generation unit 560 generates the PHICH configuration information indicating the number of OFDM symbols and the PHICH period for configuring the PDCCH determined by the OFDM symbol number determination unit 555. [ PHICH configuration information can be defined as shown in Table 5.

The transmitting unit 565 transmits PBCH, PHICH, and PDCCH to the UE. The PBCH includes the PHICH configuration information. The PHICH is based on the PHICH configuration information generated by the PHICH configuration information generation unit 560 and the PDCCH is based on the number of OFDM symbols determined by the OFDM symbol number determination unit 555. [ The receiving unit 570 receives the uplink signal from the UE.

According to the present invention, the CFI instruction for the MTC UE can be more flexible. In addition, the limitation of the number of OFDM symbols for PDCCH transmission is relaxed, and waste of radio resources can be prevented.

The foregoing description is merely illustrative of the technical idea of the present invention, and various changes and modifications may be made by those skilled in the art without departing from the essential characteristics of the present invention. Therefore, the embodiments disclosed in the present invention are intended to illustrate rather than limit the scope of the present invention, and the scope of the technical idea of the present invention is not limited by these embodiments. The 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 (12)

A method of transmitting control information for a MTC (Machine-Type Communication) user equipment (UE) in a wireless communication system,
Determining a number of Orthogonal Frequency Division Multiplexing (OFDM) symbols used for transmission of a Physical Downlink Control Channel (PDCCH) based on a PHICH (Physical Hybrid ARQ Indicator Channel) duration;
Generating PHICH configuration information indicating the PHICH period and the number of OFDM symbols; And
Transmitting a Physical Broadcast Channel (PBCH) including the PHICH configuration information to the MTC UE
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Wherein the number of OFDM symbols is 2 when the PHICH period is a normal PHICH period and the total number of downlink resource blocks is 10 or less.
2. The method of claim 1, wherein when the PHICH period is a general PHICH period and the total number of downlink resource blocks exceeds 10, an MBSFN (4-cell-specific) antenna port on a carrier supporting PDSCH Wherein the number of the OFDM symbols in the subframe is two.
2. The method of claim 1, wherein when the PHICH period is an extended PHICH period and the total number of downlink resource blocks is 10 or less, a subframe 1 of a TDD (Time Division Duplex) of a non-MBSFN (non-MBSFN) 6, and the number of OFDM symbols is 4 when the subframe is not a PRS.
A method for receiving control information by a MTC (Machine-Type Communication) user equipment (UE) in a wireless communication system,
Receiving a Physical Broadcasting Channel (PBCH) including PHICH (Physical Hybrid ARQ Indicator Channel) configuration information from a base station; And
Receiving a PHICH and a PDCCH from the base station based on a PHICH period indicated by the PHICH configuration information and a number of Orthogonal Frequency Division Multiplexing (OFDM) symbols used for transmission of a Physical Downlink Control Channel (PDCCH)
, ≪ / RTI &
Wherein the number of OFDM symbols is 2 when the PHICH period is a normal PHICH period and the total number of downlink resource blocks is 10 or less.
5. The method of claim 4, wherein, when the PHICH period is a general PHICH period and the total number of downlink resource blocks exceeds 10, an MBSFN on a carrier configured with four cell- specific antenna ports and supporting a PDSCH Wherein the number of OFDM symbols is 2 in a subframe.
5. The method of claim 4, wherein, when the PHICH period is an extended PHICH period and the total number of downlink resource blocks is 10 or less, subframe 1 of TDD (Time Division Duplex) of non-MBSFN (non- 6, and the number of the OFDM symbols is 4 when the subframe is not a PRS.
An apparatus for transmitting control information for a MTC (Machine-Type Communication) user equipment (UE) in a wireless communication system,
An OFDM symbol number determination unit for determining the number of orthogonal frequency division multiplexing (OFDM) symbols used for transmission of a physical downlink control channel (PDCCH) based on a physical hybrid ARQ indicator channel (PHICH) duration;
A PHICH configuration information generator for generating PHICH configuration information indicating the PHICH period and the number of OFDM symbols; And
A transmission unit for transmitting a PBCH (Physical Broadcasting Channel) including the PHICH configuration information to the MTC UE;
, ≪ / RTI &
Wherein the number of OFDM symbols is 2 when the PHICH period is a normal PHICH period and the total number of downlink resource blocks is 10 or less.
[8] The method of claim 7, wherein when the PHICH period is a general PHICH period and the total number of downlink resource blocks exceeds 10, an MBSFN Wherein the number of the OFDM symbols in the subframe is two.
[8] The method of claim 7, wherein when the PHICH period is an extended PHICH period and the total number of downlink resource blocks is 10 or less, a subframe 1 of TDD (Time Division Duplex) among non-MBSFN (non- 6, and the number of the OFDM symbols is 4 when the sub-frame is not a PRS.
A control information receiving apparatus by a MTC (Machine-Type Communication) user equipment (UE) in a wireless communication system,
Receives a Physical Broadcast Channel (PBCH) including PHICH (Physical Hybrid ARQ Indicator Channel) configuration information from a base station,
And a receiver for receiving the PHICH and the PDCCH from the base station based on a PHICH period indicated by the PHICH configuration information and a number of Orthogonal Frequency Division Multiplexing (OFDM) symbols used for transmission of a Physical Downlink Control Channel (PDCCH) ,
Wherein the number of OFDM symbols is 2 when the PHICH period is a normal PHICH period and the total number of downlink resource blocks is 10 or less.
11. The method of claim 10, wherein when the PHICH period is a general PHICH period and the total number of downlink resource blocks exceeds 10, an MBSFN (MBSFN) configured with four cell- specific antenna ports and supporting a PDSCH Wherein the number of the OFDM symbols in the subframe is two.
11. The method of claim 10, wherein, when the PHICH period is an extended PHICH period and the total number of downlink resource blocks is 10 or less, subframe 1 of TDD (Time Division Duplex) of non-MBSFN (non- 6, and the number of the OFDM symbols is 4 when the subframe is not a PRS.

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