JP6027247B2 - Transfer and reception of control information - Google Patents

Description

  The present disclosure relates to transferring control information at a transmission / reception point and receiving control information at a user terminal. In particular, the present disclosure relates to a method and apparatus for transferring control information for a user terminal that receives downlink control information via a downlink control channel newly introduced (defined) in a data area (eg, a transmission / reception point). About. Furthermore, the present disclosure relates to a method and apparatus (eg, user terminal) for receiving control information.

  Wireless communication systems have been designed to transfer large volumes of data to many subscribers. However, it is difficult to increase the capacity of the wireless communication system due to limited resources in the control area. Use of a downlink control channel located in the data area to overcome such limitations may be required to transfer downlink control information.

On the other hand, existing control channel elements (Control Channel Elements (CCEs)) are associated with allocation of downlink control channels in the control region. Enhanced Control Channel Elements (ECCEs) have been newly defined to allocate downlink control channels in the data domain. Therefore, a resource allocation scheme associated with newly defined ECCS may be required.

  The present embodiment provides an Enhanced Control Channel Element (ECCE) / Enhanced Resource Element Group (EREG) mapping method for downlink control channel transfer in the data area. Also, the present embodiment provides a method and apparatus for performing ECCE indexing in a distributed enhanced physical downlink control channel (EPDCCH) set.

According to at least one embodiment, there is provided a method for transferring control information at a transmission / reception point to a user terminal through a pair of data regions of two or more physical resource blocks (PRBs) in a subframe. Is done. This method forms enhanced control channel elements (Enhanced Control Channel Elements (ECCEs)), and (i) a resource element (Resource Elements (Res)) in each of the two or more PRB pairs is a frequency priority scheme. (Ii) resource elements (Res) having the same index are included in the same enhanced resource element group (Enhanced Resource Element Group (EREG)), and (iii) ) each of the ECCE, when dividing by one of the different EREG index 4 or 2, corresponding to different EREG index have the same remainder 4 (Iv) The EREG included in each of the ECCEs is located in a pair of two or more PRBs, and transfers control information to the user terminal through at least one of the ECCEs. includes to Rukoto, multiple number of the EREG constituting each of the ECCE may not reach the number of pairs of the PRB, each of the ECCE is selected by being hopped at intervals of a predetermined index Configuring the ECCE to be mapped to an EREG included in each PRB pair.

According to another embodiment, a method is provided for receiving control information at a user terminal from a transmission / reception point through a data region of a pair of two or more physical resource blocks (PRBs) in a subframe. The The method receives radio signals through at least one enhanced control channel element (Enhanced Control Channel Elements (ECCEs)), and (i) a resource element (Resource Elements (Res)) in each of the two or more PRB pairs. Are indexed repeatedly using 16 numbers according to the frequency priority method, and (ii) resource elements (Res) having the same index are the same improved resource element group (Enhanced Resource Element Group (EREG)). (Iii) each of the ECCEs has a different E with the same remainder when dividing a different EREG index by one of 4 or 2. 4 or 8 EREGs corresponding to the REG index are included, and (iv) the EREG included in each of the ECCEs is located in a pair of two or more PRBs, and obtains the control information from the received radio signal If the number of EREGs constituting each of the ECCEs is less than the number of PRB pairs, the ECCEs associated with the reception of the radio signals are hopped at a constant index interval. Mapping to an EREG included in a plurality of selected PRB pairs.

According to another embodiment, a transmission / reception point is provided for transferring control information to a user terminal through a pair of data areas of two or more physical resource blocks (PRBs) in a subframe. The transmit / receive points are configured to form enhanced control channel elements (Enhanced Control Channel Elements (ECCEs)), and (i) the resource elements (Resource Elements (Res)) of each of the two or more PRB pairs are Indexes are repeatedly indexed using 16 numbers according to the frequency priority scheme, and (ii) resource elements (Res) having the same index are grouped into the same enhanced resource element group (Enhanced Resource Element Group (EREG)). And (iii) each of the ECCEs has a different EREG index with the same remainder when dividing a different EREG index by one of 4 or 2. (Iv) the EREG included in each of the ECCEs includes a control unit located in a pair of two or more PRBs, and at least one of the ECCEs. A transmission unit that transfers control information to the user terminal, and when the number of EREGs constituting each of the ECCEs is less than the number of PRB pairs, each of the ECCEs The ECCE is configured to be mapped to EREGs included in a plurality of PRB pairs selected by hopping at a constant index interval.

According to another embodiment, a user terminal is provided that receives control information from a transmission / reception point through a data region of a pair of two or more physical resource blocks (PRBs) in a subframe. The user terminal receives a radio signal through at least one enhanced control channel element (Enhanced Control Channel Elements (ECCEs)), and (i) a resource element (Resource Elements (Res)) of each of the two or more PRB pairs. ) Is indexed repeatedly using 16 numbers according to the frequency priority method, and (ii) resource elements (Res) having the same index are the same enhanced resource element group (Enhanced Resource Element Group (EREG)). (Iii) Each of the ECCEs has a different E with the same remainder when dividing a different EREG index by one of 4 or 2. It includes 4 or 8 EREGs corresponding to the REG index, and (iv) the EREGs included in each of the ECCEs may be located in two or more PRB pairs. The control unit can acquire the control information from the received radio signal, and when the number of the EREGs constituting each of the ECCEs is less than the number of the PRB pairs, the control unit is associated with reception of the radio signal . Each of the ECCEs may be located in an EREG included in a plurality of PRB pairs selected by hopping at a constant index interval.

1 is a diagram illustrating an example of a wireless communication system to which at least one embodiment is applied. The figure of the example of the structure of the downlink resource in a LTE (Long Term Evolution) or LTE-A (LTE-Advanced) system, Comprising: One resource block pair in case of normal CP (normal cyclic prefix). The figure of two EPDCCH transfer types, local EPDCCH transfer and distributed EPDCCH transfer. A RE (Resource Element) of a PRB (Physical Resource Block) pair that is EREG-indexed by a symbol-based cyclic shift with respect to one transfer antenna port (CRS (Cell-specific Reference Signal) port CRS port 0) Mapping diagram. FIG. 6 is a diagram of RE mapping of a PRB pair that is EREG indexed with symbol-based cyclic shift for two transfer antenna ports (CRS ports 0 and 1). FIG. 6 is a diagram of RE mapping of PRB pairs that are EREG indexed with symbol-based cyclic shift for four forward antenna ports (CRS ports 0, 1, 2, and 3). FIG. 5 is a diagram of RE mapping of a PRB pair that is EREG indexed without cyclic shift for one transfer antenna port (CRS port 0). Diagram of RE mapping of PRB pairs indexed without cyclic shift for two forwarding antenna ports (CRS ports 0 and 1). Diagram of RE mapping of PRB pairs ERG indexed without cyclic shift for 4 forwarding antenna ports (CRS ports 0, 1, 2, and 3). FIG. 3 is an ECCE configuration diagram of a distributed EPDCCH set configured by two EPRBs according to the first embodiment. The ECCE block diagram in the dispersion | distribution EPDCCH set comprised by 8 EPRB which concerns on Embodiment 1. FIG. The ECCE block diagram in the distributed EPDCCH set which concerns on Embodiment 2-1. The ECCE block diagram in the distributed EPDCCH set which concerns on Embodiment 2-2. The ECCE block diagram in the distributed EPDCCH set which concerns on Embodiment 2-3. The flowchart which shows the method of the control information transfer in the transmission / reception point which concerns on at least 1 embodiment. The flowchart which shows the method of control information reception of the user terminal which concerns on other embodiment. The block diagram of the transmission / reception point which concerns on some embodiment. The block diagram of the user terminal which concerns on some embodiment.

  Hereinafter, exemplary embodiments of the present invention will be described with reference to the accompanying drawings. In the following description, the same constituent elements have the same reference numerals as much as possible even if they are displayed on other drawings. In describing this embodiment, if it is determined that a specific description of a related known configuration or function may obscure the gist of the present invention, a detailed description thereof will be omitted.

  The wireless communication system in at least one embodiment is widely used to provide various communication services such as voice and packet data. The wireless communication system includes a user equipment (User Equipment: UE) and at least one transmission / reception point. The user terminal in this specification is a comprehensive concept that means a terminal in wireless communication. Therefore, the user terminal (UE) is not only a user terminal in WCDMA (registered trademark) and LTE, high-speed packet access (HSPA), but also MS (Mobile Station) and UT (User Terminal) in GSM (registered trademark). , SS (Subscriber Station) and / or wireless device (wireless device) etc.

  The transmission / reception point may be referred to as a station that communicates with the user terminal. Such a transmission / reception point includes a base station (BS) or a cell, a node-B (Node-B), an eNB (evolved Node-B), a sector (Sector), a site (Site), and a BTS ( Base Transceiver System, Access Point, Relay Node, RRH (Remote Radio Head), RU (Radio Unit), and the like may be called different terms.

  That is, in this specification, a base station or a cell is a base station controller (BSC) in code division multiple access (CDMA), a NodeB in WCDMA (registered trademark), an eNB in LTE, or a sector (site). ) Etc. should be construed as a comprehensive meaning indicating some areas or functions covered. Thus, the concept of transmit / receive points, base stations and / or cells includes a wide range of areas such as megacells, macrocells, microcells, picocells, femtocells, and so on. Further, such a concept may include a range of communication such as a relay node, an RRH (Remote Radio Head), and an RU (Radio Unit).

  In this specification, a user terminal and a transmission / reception point are two transmission / reception entities used for embodying the technology or technical idea described in this specification, and are used as a comprehensive meaning and specifically referred to. It is not limited by terms or words. The user terminal and the transmission / reception point are two (Uplink or Downlink) transmission / reception entities used for embodying the technology or the technical idea described in the present invention, are used as a comprehensive meaning, and are specifically referred to. It is not limited by terms or words. Here, uplink (UL) transmission / reception means a method of transmitting / receiving data to / from a base station by a user terminal. Or downlink (DL) transmission / reception means the system which transmits / receives data to a user terminal by a base station.

  Multiple access techniques applied to a wireless communication system include CDMA (Code Division Multiple Access), TDMA (Time Division Multiple Access), FDMA (Frequency Division Multiple Access), OFDMA (Orthogonal Frequency Division Multiple Access), OFDM-FDMA, Various multiple access techniques such as OFDM-TDMA and OFDM-CDMA can be used. At least one embodiment includes asynchronous wireless communication that evolves to LTE and LTE-advanced via GSM®, WCDMA®, HSPA, and synchronous wireless communication that evolves to CDMA, CDMA-2000, and UMB. Applicable to resource allocation such as field. This embodiment should not be construed as being limited or restricted to a specific wireless communication field, but should be construed as including all technical fields to which the idea of the present invention can be applied.

  In uplink transfer and downlink transfer, at least one of a TDD (Time Division Duplex) method and an FDD (Frequency Division Duplex) method can be used. Here, the TDD can perform uplink / downlink transfer using different times. The FDD can perform uplink / downlink transmission using different frequencies.

  Further, in an LTE or LTE-A system that complies with a corresponding standard, an uplink and a downlink can be configured based on one carrier or carrier pair. Uplink and / or downlink are controlled through control channels such as PDCCH (Physical Downlink Control CHannel), PCFICH (Physical Control Format Indicator CHannel), PHICH (Physical Hybrid ARQ Indicator CHannel), and PUCCH (Physical Uplink Control CHannel). Transfer information. Data is configured and transferred by data channels such as PDSCH (Physical Downlink Shared CHannel) and PUSCH (Physical Uplink Shared CHannel).

  In this specification, the term cell refers to a component carrier having a coverage of a signal transferred from a transmission point or a transmission / reception point or a coverage of a signal transferred from a transmission / reception point (transmission point or transmission / reception point). carrier), the transmission / reception point itself. Here, the term “transmission / reception point” means a transmission point for transmitting / transmitting a signal, a reception point for receiving a signal (reception point), and a combination (transmission / reception point) thereof.

  FIG. 1 illustrates an example of a wireless communication system to which at least one embodiment is applied.

  Referring to FIG. 1, a wireless communication system 100 includes a coordinated multi-point transmission / reception system (CoMP system) in which two or more transmission / reception points cooperate to transmit a signal, and cooperative multi-antenna transmission. It can be one of a coordinated multi-antenna transmission system and a cooperative multi-cell communication system. Here, the CoMP system can cooperatively transfer signals between a plurality of transmission / reception points. The CoMP system 100 may include a plurality of transmission / reception points 110, 112 and at least one user terminal (UE) 120 and 122.

  The transmission / reception point may be one of a transmission / reception point (for example, eNB) 100 and a transmission / reception point (for example, RRH) 112, as shown in the figure. Here, the eNB 110 may be a base station or a macro cell (or a macro node). The RRH 112 may be at least one pico cell having a high transfer power that is connected to the eNB 110 via an optical cable or an optical fiber and is wire-controlled. Further, the RRH 112 may be at least one pico cell having high transfer power or low transfer power in the macro cell region. The transmission / reception point eNB 110 and the RRH 112 may have the same cell ID, or may have different cell IDs.

  Hereinafter, downlink (DL) means a communication or communication path from the transmission / reception points 110 and 112 to the user terminal 120. Uplink (UL) means a communication or communication path from the user terminal 120 to the transmission / reception points 110 and 112. In the downlink, the transmitter may be part of the transmit / receive points 110 and 112 and the receiver may be part of the user terminals 120 and 122. In the uplink, the transmitter may be part of the user terminal 120 and the receiver may be part of the transmit / receive points 110 and 112.

  Hereinafter, a situation in which a signal is transmitted and received through a channel such as PUCCH, PUSCH, PDCCH, and / or PDSCH may be described as a form of transferring or receiving PUCCH, PUSCH, PDCCH, and / or PDSCH.

  eNB 110 performs downlink transfer to user terminals (eg, 120 and / or 122). The eNB 110 transfers the PDSCH corresponding to the main physical channel for unicast transmission. In addition, the eNB (eg, 110) transfers the PDCCH for transferring downlink control information such as scheduling required for PDSCH reception and scheduling approval information for transfer on the uplink data channel (eg, PUSCH). can do. Hereinafter, transmission / reception of a signal via a channel may be described as transmission / reception of the channel.

  In wireless communication, one radio frame (radio frame) is composed of 10 subframes, and one subframe is composed of two slots. The radio frame has a length of 10 ms, and the subframe has a length of 1.0 ms. In general, the basic unit of data transmission is a subframe unit, and downlink or uplink scheduling is performed in subframe units. In the case of a normal cyclic prefix (CP), one slot includes 7 OFDM symbols. In the case of an extended cyclic prefix (extended cyclic prefix), one slot includes six OFDM (Orthogonal Frequency Division Modulation) symbols.

  In radio communication, the frequency domain can be configured in units of subcarriers at intervals of 15 kHz, for example.

  In the downlink, time-frequency resources can be determined in units of resource blocks (RBs). The resource block can be composed of one slot on the time axis and 180 kHz (12 subcarriers) on the frequency axis. A resource element composed of one subcarrier (2 slots) on the time axis and 12 subcarriers on the frequency axis can be called a resource block pair (RBP). The total number of resource blocks varies depending on the system bandwidth.

  A resource element (RE) can be composed of one OFDM symbol on the time axis and one subcarrier on the frequency axis. One resource block pair may include 14 × 12 (for normal CP) or 12 × 12 (for extended CP) resource elements.

  FIG. 2 is an example of a downlink resource structure in an LTE (Long Term Evolution) or LTE-A (LTE-Advanced) system, and illustrates a pair of resource blocks in the case of a normal CP (normal cyclic prefix). To do.

  Referring to FIG. 2, in the case of normal CP, one resource block pair consists of 14 OFDM symbols (l = 0, 1,..., 13) and 12 subcarriers (k = 0,...). 11). In the embodiment illustrated in FIG. 2, one resource block pair may include 14 OFDM symbols. Of the 14 symbols, the area (l = 0 to 2) consisting of the three front OFDM symbols is PCFICH (Physical Control Format Information CHannel), PHICH (Physical Hybrid ARQ Indicator CHannel), PDCCH (Physical Downlink Control CHannel). The control area 210 may be allocated for a control channel such as The remaining area (l = 3 to 13) may be a data area 220 allocated for a data channel such as PDSCH (Physical Downlink Shared CHannel). Although FIG. 2 illustrates that three OFDM symbols are allocated for the control region 210, one to four OFDM symbols may be allocated for the control region 210 in some embodiments. is there. The size information of the OFDM symbol in the control area 210 can be transmitted via PCFICH. Here, the size information can be set to the number of OFDM symbols.

  The PDCCH can be transferred over the entire system band, and the PDSCH can be transferred based on resource blocks. The user terminal confirms the corresponding PDCCH (for example, PDCCH allocated to the user terminal), and enters micro sleep mode when there is no data (for example, data for the user terminal) in the corresponding PDCCH. be able to. Therefore, the power consumption of the user terminal can be reduced in the data area 120.

  Referring to FIG. 2, a reference signal can be mapped to a specific resource element in the downlink. That is, the common reference signal (or cell-specific reference signal (CRS) 230, demodulation reference signal (DM-RS) (or UE-specific reference signal (DeModulation Reference Signal or UE)). -specific Reference Signal)) 232 and 234, Channel Status Information Reference Signal (CSI-RS), etc. can be transmitted through the downlink, etc. In FIG. Only 234 is shown.

  The CRS 230 in the control region 210 can be used for channel estimation for decoding the PDCCH. The CRS 230 in the data area 220 can be used for downlink channel measurements. Channel estimation for data decoding in the data region 220 can be performed using DM-RS 232 and / or 234. DM-RSs 232 and 234 are multiplexed as reference signals for multiple layers using orthogonal codes. For example, in the case of four layer transfers, two different reference signals are multiplexed for each reference signal group by applying an orthogonal code of length 2 to two reference signal resource elements that are continuous on the time axis. can do. In the case of eight layer transfers, four different reference signals are multiplexed for each reference signal group by applying a quadrature signal of length 4 to four reference signal resource elements distributed along the time axis. Can be

  In the case of one layer transfer or two layer transfer, the reference signal of each layer can be transferred using only one DM-RS group (for example, DM-RS group 1 (232)). An RS group (eg, DM-RS group 2 (234)) can be used for data transfer. The DM-RS corresponding to each layer is transmitted by applying the same precoding applied to the corresponding layer. Therefore, the receiving side (for example, user terminal) can decode data without the precoding information applied at the transmitting end (for example, base station).

  In order to efficiently use limited resources in a wireless communication system, a control channel is required. However, the resource of the control area 210 becomes a system overhead and reduces the resource of the data area 220 used for data transfer. In an OFDM-based LTE system, one resource-block pair (RBP) can be composed of 14 or 12 OFDM symbols. Of these OFDM symbols, a maximum of three OFDM symbols are used for the control region 210 and the remaining OFDM symbols are used for the data region 220. On the other hand, in the LTE-A system capable of transferring data to a larger number of users, the increase in system capacity is limited by the resources of the conventional limited control area (for example, 210). Therefore, in order to increase control channel resources, a control channel transmission / reception method for multiple users using a space division multiplexing technique or the like in the data region 220 may be required. In other words, such a method is to transmit and receive control channels in the data region 220. For example, the control channel transferred in the data region 220 may be referred to as an extended PDCCH or an enhanced PDCCH (EPDCCH), but is not limited thereto.

  In the existing (or existing) 3GPP LTE / LTE-A rel-8 / 9/10 system, for the reception of downlink DCI, all user terminals are the first, second, or first from the downlink subframe. It depends on the PDCCH (Physical Downlink Control Channel) transferred through the third OFDM symbol (when system band> 10 PRB) or the second, third or fourth OFDM symbol (system band ≦ 10 PRB) from the beginning. The basic unit of PDCCH transfer for any user terminal may be a control channel element (CCE). Here, one CCE can be composed of nine resource element groups (REG). One REG can be composed of four continuous resource elements (RE) on the frequency axis. In particular, four consecutive resource elements (RE) of one REG transfer different physical channels (eg, PCFICH, PHICH) and physical signals (eg, CRS) existing in the PDCCH region of the corresponding downlink subframe. Can be selected from the remaining resource elements (RE) excluding resource elements (RE).

  In order to perform EPDCCH resource mapping for an arbitrary user terminal, REG of conventional PDCCH and EREG (Enhanced REG) or ECCE (Enhanced CCE) corresponding to CCE can be introduced or defined in EPDCCH.

  Unlike the above-described legacy PDCCH, the EPDCCH newly introduced (defined) in the 3GPP LTE / LTE-Arelease11 and the system related thereto is a DwPTS (Downlink Pilot Time Slot) of a downlink subframe or a special subframe. Allocated to the PDSCH region. In addition, 3GPP LTE / LTE-A release 11 and its subsequents are defined to allocate K EPDCCH sets for user terminals configured to receive DCI (Downlink Control Information) via the EPDCCH. To do. Here, each of the EPDCCH sets can be configured with a group of 'M' PRBs. M is a natural number greater than or equal to 1 and less than or equal to the number of PRBs associated with the downlink band. The maximum value of K can be selected as one of 2, 3, 4, and 6. Also, each EPDCCH set determined for any user terminal may have a different M value.

  In addition, each EPDCCH set can be determined as one of a distributed type or a localized type, and can be signaled according to the determined type.

Depending on the EPDCCH transfer type, the EPDCCH set may be a localized type or a distributed type. M described above is a local type and can be 1 or 2 ⁿ (n = 1, 2, 3, 4, 5), but is not limited thereto. On the other hand, M may be 2, 4, 8, 16 in a distributed manner, but is not limited thereto.

  FIG. 3 illustrates two EPDCCH transmission types, localized EPDCCH transmission and distributed EPDCCH transmission.

The number of downlink PRBs (Physical Resource Blocks) is N _PRB . Here, the downlink PRB can configure a system band supported by an arbitrary cell configured by a communication carrier. In this case, as shown in FIGS. 3a and 3b, the transfer type of EPDCCH may correspond to one of local EPDCCH transfer and distributed EPDCCH transfer. Therefore, the ECCE structure and the number of REs (Resource Elements) constituting one ECCE may vary depending on each EPDCCH transfer type. Instead, the ECCE structure and the number of REs (Resource Elements) constituting one ECCE may be the same regardless of the EPDCCH transfer type.

  The local EPDCCH transfer illustrated in FIG. 3a means that one ECCE is transferred in one resource block pair (for example, one PRB pair). On the other hand, the distributed EPDCCH transfer illustrated in FIG. 3b means that one ECCE is transferred while being located in at least two resource block pairs (for example, two PRB pairs).

On the other hand, K EPDCCH sets can be allocated for one user terminal. In this case, each of the EPDCCH set because a distributed type or localized type, _{K L} number of localized type of EPDCCH and _{K D} number of distributed type EPDCCH for one user terminal can be allocated. That is, the sum of K _L and K _D can be K (K _L + K _D = K).

  In the case of newly defined EREG / ECCE, a total of 16 EREGs (EREG # 0 to EREG # 15) can be included in one PRB pair constituting each EPDCCH set. In particular, one PRB pair consists of (i) frame structure type, (ii) subframe configuration, (iii) CP (Cyclic Prefix) length, and (iv) legacy PDCCH control. Regardless of the size of the area and / or the presence or absence of (v) the remaining reference signals excluding DM-RS (eg, CRS, CSI-RS, PRS, etc.), a total of 16 EREGs can be included.

  Specifically, in the case of a normal cyclic prefix (CP), one PRB pair constituting an EPDCCH set may include a total of 168 resource elements (REs) (for example, 12 × 14 = 168 REs). it can. In this case, EREG indexing is performed on the remaining elements (RE) (eg, 144 REs) obtained by removing 24 resource elements (RE) for DM-RS from 168 resource elements (REs). Can be carried out. In other words, EREG indexing can be performed using 16 numbers (eg, 0, 1, 2,..., 15) in a frequency first and then time manner. Therefore, resource elements (REs) can be numbered (indexed) from 0 to 15. Similarly, in the case of the extended cyclic prefix (CP), one PRB pair constituting an EPDCCH set may include a total of 144 resource elements (RE) (for example, 12 × 12 = 144 REs). it can. In this case, EREG indexing is performed on the remaining resource elements (RE) (for example, 128 REs) obtained by removing 16 resource elements (RE) for DM-RS from 144 resource elements (Res). Can be accomplished. In other words, EREG indexing can be performed using 16 numbers (eg, 0, 1, 2,..., 15) in a frequency first and then time manner. Accordingly, the corresponding resource elements (REs) can be numbered (indexed) from 0 to 15.

  Embodiments related to EREG indexing for one pair of PRBs constituting a certain EPDCCH set in a normal DL subframe corresponding to a normal cyclic prefix (CP) are shown in FIGS. 9. 4 to FIG. 9, the portion that is displayed with diagonal lines but not numbered indicates a resource element (RE) used for DM-RS, and the number is described while being displayed with grids or diagonal lines. The part indicates a resource element (RE) used for CRS transfer.

  FIG. 4 illustrates a resource element (RE) mapping of a physical resource block (PRB) pair that is EREG-indexed with a symbol-based cyclic shift for one transfer antenna port (eg, CRS port 0).

  Referring to FIG. 4, EREG can be numbered (for example, indexed) from 0 to 15 by a frequency priority method (that is, a method that prioritizes frequency and then uses time). In the embodiment illustrated in FIG. 4, the indexing can be performed using a symbol-based cyclic shift. More specifically, as shown in FIG. 4, after the resource element (RE) of the first symbol 400 is indexed as 11 (ie, index 11), the adjacent resource element (RE) of the second symbol 410 is 12 ( That is, it is continuously indexed as index 12). After the resource element (RE) of the second symbol 420 is indexed as 7 (ie, index 7) by the same method, the adjacent resource element (Re) of the third symbol 430 is continuously 8 (ie, index 8). ) Is indexed.

  The physical resource block (PRB) pair illustrated in FIG. 4 may be associated with CRS port 0. As shown in FIG. 4, a CRS can be mapped to 8 resource elements (RE). In other embodiments, the CRS may be mapped to resource elements (Res) at other locations by frequency shifts.

  FIG. 5 illustrates a resource element (RE) mapping of a pair of physical resource blocks (PRBs) EEG indexed with symbol-based cyclic shift for two forward antenna ports (eg, CRS ports 0 and 1). Yes. FIG. 6 illustrates an RE mapping of a PRB pair that is EREG indexed with symbol-based cyclic shift for four forward antenna ports (eg, CRS ports 0, 1, 2, and 3).

  The resource element (RE) shown in FIGS. 5 and 6 can be indexed by symbol-based cyclic shift in the same manner as shown in FIG. In FIG. 5, the CRS can be mapped to 8 additional REs for CRS ports 0 and 1 as well as the REs for the CRS illustrated in FIG. In FIG. 6, the CRS can map to CRS ports 0, 1, 2 and 3 as well as the RE for the CRS illustrated in FIG.

  When EREG indexing is performed for each OFDM symbol, FIGS. 4 to 6 illustrate an embodiment in which a cyclic shift is applied, and FIGS. 7 to 9 are embodiments in which a cyclic shift is not applied. Is illustrated.

  FIG. 7 illustrates a RE mapping of a pair of PRBs that are EREG indexed without cyclic shift for one transfer antenna port (eg, CRS port 0). FIG. 8 illustrates the RE mapping of a pair of PRBs that are EREG indexed without cyclic shift for two forwarding antenna ports (eg, CRS ports 0 and 1). FIG. 9 illustrates the RE mapping of a pair of PRBs that are EREG indexed without cyclic shift for four forward antenna ports (eg, CRS ports 0, 1, 2, and 3).

  7 to 9, the CRS can be mapped in the same way as in FIGS. However, the indexing method used may be different.

  Referring typically to FIG. 7, EREG is numbered (eg, indexed) in a frequency-first manner (ie, a frequency first and then time manner). )it can. In the embodiment illustrated in FIG. 7, the indexing can be performed without a symbol-based cyclic shift. More specifically, as shown in FIG. 7, after the resource element (RE) of the first symbol 700 is indexed as 11 (that is, index 11), the resource element (RE) of the second symbol 710 that is the next order. Are continuously indexed as 12 (ie, index 12). Here, RE 710 indexed as 12 is not adjacent to RE 700 indexed as 11. In the same manner, after the resource (RE) of the second symbol 720 is indexed as 7 (ie, index 7), the adjacent resource element (Re) of the third symbol 730 in the next order is 8 (ie, index). 8) can be continuously indexed. Here, RE 730 indexed as 8 is not adjacent to RE 700 indexed as 7.

  4 to 9, REs having the same index are grouped into one EREG. Accordingly, a total of 16 EREGs (for example, EREG # 0 to EREG # 15) can be allocated to one PRB pair. 4-9 illustrate an embodiment associated with a normal CP PRB pair. That is, one PRB pair of the normal CP can include a total of 16 EREGs. Similarly, a total of 16 EREGs (EREG # 0 to EREG # 15) can be assigned to PRB pairs of extended CPs.

  Each of the EREGs (EREG # 0, EREG # 1,..., EREG # 15) set as one PRB pair according to FIGS. 4 to 9 can be composed of 9 REs. However, as shown in FIGS. 4 to 9, the number of REs that can actually be used for EPDCCH transmission per EREG may vary depending on the number of transfer antenna ports (or CRS port numbers) and the legacy PDCCH size.

  Referring again to FIG. 4, the total number of REs corresponding to index # 0 is nine. However, if the region associated with the first three OFDM symbols (l = 0-2) is determined as the control region, the RE in this control region cannot transfer the EPDCCH, and from the RE that can be used for EPDCCH transfer. Excluded. Therefore, EREG # 0 is composed of a total of 6 usable REs. In the case of EREG corresponding to index # 1, the total number of REs indexed as # 1 is nine. In this case, (i) is RE in the control region (for example, the region associated with the first three OFDM symbols (l = 0 to 2)), and (ii) RE in which the CRS is mapped (for example, in FIG. RE) labeled 440 is excluded. Therefore, EREG # 1 can be composed of a total of 5 usable REs.

  Each ECCE serving as a basic unit of EPDCCH transmission may include N EREGs depending on the subframe type and the length of the CP. Specifically, the value of N can be determined as follows.

  In at least one embodiment, for (i) normal subframes of normal CPs, and (ii) normal CPs and special subframes of configuration 3, 4, and 8 special subframes, The value of N can be determined as 4 (N = 4). That is, in this case, when 16 EREGs are included in one PRB pair, since each ECCE is 4 EREGs, a total of 4 ECCEs can be configured.

  In another embodiment, (i) a normal subframe of an extended CP, (ii) a special subframe of normal CP and special subframe configurations 1, 2, 6, 7, and 9, and (iii) an extended CP For special subframes with special subframe configurations 1, 2, 3, 5, and 6, the value of N can be set to 8 (N = 8). In this case, when 16 EREGs are included in one PRB pair, since each ECCE is 8 EREGs, a total of 2 ECCEs can be configured.

  For a certain downlink subframe (ie, normal DL subframe), the existing PDCCH can be transmitted through the first, second, or third OFDM symbol from the beginning, or the second, third, or fourth OFDM symbol from the beginning. One CCE can be composed of nine REGs. Therefore, the CCE of PDCCH can be composed of 9 × 4 = 36 REs.

  However, in the case of EPDCCH, as described with reference to FIGS. 4 to 9, the legacy control region size (for example, the size of the control region of legacy PDCCH) and other reference signals (for example, CRS, CSI-RS, etc.) EREG indexing is performed for each RE without taking into account the RE used for. For this reason, the number of REs that can actually be used for EPDCCH transfer varies depending on the legacy control region size in a certain downlink subframe and the presence or absence of other reference signals (for example, CRS, CSI-RS, etc.). In other words, the number of REs that can be used for EPDCCH transfer may change for each EREG. Therefore, in the case of ECCE that is actually a basic unit of EPDCCH transfer, there may be RE imbalances in which the number of REs that can actually be used differs for each ECCE.

  In order to overcome such problems, the present embodiment provides a method for mapping EREGs constituting each ECCE. In particular, the present embodiment provides a method for performing ECCE / EREG mapping (or ECCE to EREG mapping) in a distributed EPDCCH set (for example, a distributed type EPDCCH set).

  In the case of distributed EPDCCH transmission, in order to maximize the frequency diversity gain, EREGs constituting one ECCE are distributed to M PRB pairs included in the corresponding EPDCCH set. Can be configured. In view of these points, the present embodiment provides a method for performing ECCE / EREG mapping in a distributed type EPDCCH set.

  Specifically, as described above, the present embodiment provides a method of configuring each ECCE with a pair of M PRBs configuring a distributed type EPDCCH set. In particular, this embodiment considers legacy PDCCH and CRS transferred through the downlink pilot time slot (DwPTS) region of all downlink subframes and special subframes. Accordingly, the present embodiment provides a relatively optimal ECCE / EREG mapping method that takes into account the number of REs that can be used for EPDCCH transfer in the corresponding PRB pair.

  4 to 9, each EREG (EREG # 0, EREG # 1,..., EREG # 15) configured in one PRB pair may include nine REs. However, the number of REs that can be used for each EREG is determined by the number of CRS ports and the size of the legacy PDCCH, as illustrated in FIGS. Here, the usable RE may indicate an RE that can be used for EPDCCH transfer. When the EPDCCH set is configured by the legacy PDCCH size and CRS port settings corresponding to the normal downlink subframe as illustrated in FIG. 4, the following <Table 1> to <Table 3> are EPDCCH: The number of REs that can be used for each EREG index in one PRB pair included in the set can be indicated.

  Table 1 above shows the number of usable resource elements (REs) for each EREG according to each CRS port setting when the legacy PDCCH size is '1' OFDM symbol. Here, <Table 1> is created based on EREG indexing to which no cyclic shift is applied.

  Table 2 above shows the number of usable REs for each EREG according to each CRS port setting when the legacy PDCCH size is '2' OFDM symbol. Here, Table 2 is created based on EREG indexing to which no cyclic shift is applied.

  Table 3 above shows the number of usable REs for each EREG according to each CRS port setting when the legacy PDCCH size is '3' OFDM symbol. At this time, Table 3 is created based on EREG indexing to which no cyclic shift is applied.

  Referring to Table 1 to Table 3, it can be seen that the number of REs that can be used for EPDCCH transfer differs for each EREG. For this reason, the number of REs that can be used for each EREG may differ depending on the method for assigning EREG to ECCE.

  In consideration of this situation, the present embodiment provides an ECCE / EREG mapping method in a distributed type EPDCCH set.

  When a certain EPDCCH set is configured with M PRB pairs, the PRB pair associated with the present embodiment is improved to distinguish the PRB corresponding to the unit of the existing PDSCH transfer with an improved physical resource block (EPRB). ) (Enhanced Physical Resource Block). The EPRB index is displayed as EPRB # m. More specifically, the M EPRBs are arranged in the ascending order of the indexes of PRB pairs (that is, PRB indexes) constituting the EPDCCH set. . . , EPRB # (M-1) can be numbered (ie, indexed). In other words, EPRB indexing can be performed sequentially from the smallest PRB pair to the largest PRB pair. Here, the smallest PRB pair may be the PRB pair having the lowest PRB index, and the largest PRB pair may be the PRB pair having the largest PRB index.

Embodiment 1

  For distributed EPDCCH transmission, Embodiment 1 can provide a method for maximizing frequency diversity gain, which is an important performance indicator. More specifically, in the first embodiment, when the distributed EPDCCH set includes M EPRBs, each ECCE constituting the distributed EPDCCH set may be configured through N distributed EPRBs according to the following two conditions.

  If 'condition 1-1' (ie, N ≧ M), each ECCE is mapped to N / M EREGs for each EPRB, and a total of M EPRBs (ie, EPRB # m (m = 0, 1, 2, ..., M-1)) and can be mapped to N EREGs. Here, each ECCE can be composed of N EREGs.

  In the case of 'condition 1-2' (ie, N <M), each ECE is mapped with one EREG for each EPRB. Thus, each ECCE is mapped to N corresponding EREGs through a total of N distributed EPRBs. Here, each ECCE can be composed of N EREGs. Here, N corresponding EPRBs correspond to N EPRBs having an M / N EPRB interval among the M EPRBs constituting the corresponding EPDCCH set.

  For example, two PRB pairs (M = 2) are configured in a normal cyclic prefix (CP) normal downlink subframe to form a distributed EPDCCH set for 'EPDCCH user terminal'. Can be assigned. Here, the EPDCCH user terminal indicates a user terminal to which the EPDCCH is applied. In this case (ie, when M = 2), the indexing procedure of the two PRB pairs that make up the corresponding EPDCCH set corresponds from the smallest PRB pair (eg, the PRB pair with the smallest PRB index). It can be performed sequentially in ascending order of PRB index. Therefore, the two PRB pairs can be indexed as EPRB # 0 and EPRB # 1, respectively. In this case, the number of EREGs constituting one ECCE in the normal downlink subframe of the normal CP may be 4 (N = 4). Therefore, according to the above condition 1-1, each ECCE includes (i) 2 (= 4/2) EREGs allocated to EPRB # 0 and (ii) two EREGs allocated to EPRB # 1. It can be composed of EREGs.

  FIG. 10 is an ECCE configuration diagram of a distributed EPDCCH set configured by two EPRBs according to the first embodiment.

  Referring to FIG. 10, the distributed EPDCCH set can be configured with two PRB pairs of EPRB # 0 and EPRB # 1. According to the above condition 1-1, each ECCE can be composed of four EREGs including (i) two EREGs assigned to EPRB # 0 and (ii) two EREGs assigned to EPRB # 1.

  In other embodiments, 8 PRB pairs (M = 8) may be allocated for the distributed EPDCCH set for EPDCCH user terminals in the normal downlink normal downlink subframe. Here, the EPDCCH user terminal indicates a user terminal to which the EPDCCH is applied. In this case (ie, when M = 8), the indexing procedure for the 8 PRB pairs that make up the corresponding EPDCCH set is determined from the smallest PRB pair (ie, the PRB pair with the low PRB index) to the corresponding PRB. Can be performed sequentially in ascending order of the index. Therefore, the eight PRB pairs are respectively EPRB # 0, EPRB # 1,. . . , EPRB # 7. Even in this case, the number of EREGs constituting one ECCE in the normal downlink subframe of the normal CP may be 4 (N = 4). Thus, each ECCE can be configured with one EREG selected for each distributed EPRB. Here, the distributed EPRBs may correspond to N (N = 4) having an EPRB interval of M / N = 8/4 = 2. In other words, four EREGs may be mapped for the corresponding ECCE transfer. More specifically, one ECCE includes (i) one EREG selected from EPRB # 0, (ii) one EREG selected from EPRB # 2, and (iii) one EREG selected from EPRB # 4. And (iv) 4 EREGs including one EREG selected from EPRB # 6. Instead, one ECCE is (i) one EREG selected from EPRB # 1, (ii) one EREG selected from EPRB # 3, and (iii) one EREG selected from EPRB # 5, And (iv) 4 EREGs including 1 EREG selected from EPRB # 7.

  FIG. 11 is an ECCE configuration diagram of a distributed EPDCCH set including eight EPRBs according to the first embodiment.

  Referring to FIG. 11, the distributed EPDCCH set may be configured with 8 PRB pairs from EPRB # 0 to EPRB # 7. As shown in FIG. 11, one ECCE can be configured by assigning one EREG to each EPRB # 0, EPRB # 2, EPRB # 4, and EPRB # 6 according to the above condition 1-2.

Embodiment 2

  In order to configure one ECCE with a distributed EPDCCH set, together with the EPRB mapping method described in Embodiment 1 above, an EREG selection method (that is, a method of selecting an EREG (or a plurality of EREGs) in a corresponding EPRB ) Is defined. Here, the following three types of ECCE / EREG mapping methods are provided by combining the “EREG selection method” and the “EPRB hopping method of the first embodiment”.

Embodiment 2-1.

  As a first embodiment, a corresponding ECCE may be configured by 'EREG having the same index' selected from each of the EPRBs mapped to configure one ECCE according to the first embodiment. More specifically, in order to construct one ECCE, N / M EREGs can be mapped for each EPRB in the case of the above condition 1-1. On the other hand, in the case of the condition 1-2, one EREG can be mapped for each EPRB. In this case, each ECCE can be configured by mapping 'EREG' having the same index. The total number (16 / N) × M ECCEs (ECCE # i, i = 0, 1, 2,..., (16 / N) × M) constituting the corresponding EPDCCH set is (i) Indexing can be done in order of lowest EREG index and (ii) EPRB index associated with ECCE. That is, when ECCE is configured according to the EPRB mapping of Embodiment 1 above, the ECCE index is selected from the corresponding EPRB (ie, the EPRB determined by Embodiment 1 for each ECCE). Can be performed sequentially from the ECCE associated with the smallest EREG (ie, the EREG with the smallest EREG index). That is, the corresponding ECCEs can be numbered (ie, indexed) sequentially from ECCE # 0. In addition, as in the case of the above condition 1-2, each ECCE is mapped to N different EPRBs, and the EREG index selected from the EPRBs constituting each corresponding ECCE is the same during the ECCE. ECCE indexing can start with the ECCE mapped to the smallest EPRB index. That is, the EREGs constituting the ECCE # i in the corresponding EPDCCH set can be determined by the following <Equation 1> and <Equation 2>.

<Formula 1>
i = 0, 1,. . . , (16 / N) × M−1, N ≧ M,
ECCE # i = {EREG #n of EPRB #m}.

  In Equation 1, m = 0, 1,. . . , M−1 and n = n (i),. . . , N (i) + (N / M) −1, and n (i) = i × (N / M).

<Formula 2>
i = 0, 1,. . . , (16 / N) × M−1, N <M,
ECCE # i = {EREG #n (i) of EPRB #m (a)}.

  In Equation 2, a = 0, 1,. . . , N−1, m (a) = (M / N) × a + (i mod (M / N), and n (i) = [i × N / M], where [x ] Represents a maximum integer not exceeding x.

  FIG. 12 is an ECCE configuration diagram in the distributed EPDCCH set according to the embodiment 2-1.

  In FIG. 12, the number of EREGs constituting the ECCE (“N”) is “4” (N = 4), and “i” corresponding to the ECCE index (that is, ECCE index #i) is “ It may be 0 ′ (i = 0).

  FIG. 12a is a configuration diagram of ECCE according to the above-described <Equation 1>. Referring to FIG. 12a, the number (“M”) of EPRBs constituting the EPDCCH set may be ‘2’ (M = 2). If such variable values (for example, N = 4, i = 0, and M = 2) are applied to the above-described <Equation 1>, n (i) = i × N / M = 0 × 4/2 = 0, n (i) + N / M−1 = 1. Accordingly, ECCE # 0 may be {EREG # 0 and EREG # 1 of EPRB # 0, and EPRB # 1}. In other words, as shown in FIG. 12a, (i) EREG # 0 and EREG # 1 selected from EPRB # 0, (ii) EREG # 0 and EREG # 1 selected from EPRB # 1, and ECCE # 1. 0 can be configured.

  FIG. 12B is a configuration diagram of ECCE according to the above-described <Equation 2>. Referring to FIG. 12b, the number (“M”) of EPRBs constituting the EPDCCH set may be '8' (M = 8). When such variable values (for example, N = 4, i = 0, and M = 8) are applied to the above-described <Equation 2>, n (i) = [i × N / M] = [0 × 4]. / 8] = [0] = 0, m (a) = (M / N) × a + (i mod (M / N)) = (8/4) × a + (0 mod (8/4)) = 2a + 0 = 2a. For a = 0, 1, 2, 3, m (a) = {0, 2, 4, 6}. Accordingly, ECCE # 0 may be {EREG # 0 of EPRB # 0, EPRB # 2, EPRB # 4, EPRB # 6}. In other words, as shown in FIG. 12b, (i) EREG # 0 selected from EPRB # 0, (ii) EREG # 0 selected from EPRB # 2, and (iii) EREG # selected from EPRB # 4. 0, (iv) ECE # 0 selected from EPRB # 6 may constitute ECCE # 0.

Embodiment 2-2

  In another embodiment, a corresponding ECCE may be configured with an 'EREG with a shifted index' selected from each of the EPRBs mapped to configure one ECCE according to Embodiment 1. According to the first embodiment, the hopping size of an EPRB index for selecting an EREG that constitutes a certain ECCE is (i) one EPRB (in the case of the above condition 1-1), or (ii) M / N EPRBs (In the case of the above-mentioned condition 1-2).

  Hereinafter, this embodiment will be specifically described in relation to the above description (for example, hopping size). When the distributed EPDCCH set is composed of M EPRBs (for example, EPRB # 0 to EPRB # (M-1)), the EPRB for EREG selection (for example, the EPRB for which EREG is selected) is M EPRBs. Can be mapped (ie, determined) through the EPRB hopping procedure. Here, the EPRB hopping procedure may start with EREG # 0 of EPRB # 0 and have a hopping size according to the conditions of Embodiment 1 above. The EREG used for ECCE configuration can be determined by selecting one EREG for each mapped EPRB (ie, selecting one EREG from each of the mapped EPRBs through the EPRB hopping procedure). In particular, in this case, each time EPRB hopping is performed, the EREG index selected from the corresponding EPRB can be increased by ‘1’ (see FIG. 9B). If the last EPRB (largest EPRB) constituting the corresponding EPDCCH set is reached before mapping the Nth EREG to configure a certain ECCE, the first EPRB (ie, the smallest EPRB) is also reached. Cyclic shifting back to can be applied to continue EREG mapping.

  That is, when the hopping size according to the first embodiment is “1”, that is, when N ≧ M (for example, N = 4, M = 3), ERB # 0 is selected from EPRB # 0, and EPRB # 1 is selected. EREG # 1 can be selected, and EREG # 2 can be selected from EPRB # 2. After returning to EPRB # 0 again, EPRB # 0 to EREG # 3 can be selected again. Therefore, N EREGs can be selected and mapped through a total of M EPRBs. In particular, when N> M, one EPRB (or a plurality of EPRBs) can be selected once or more.

  Thus, when the first ECCE / EREG mapping for selecting N EREGs is completed as described above, the second ECCE / EREG mapping can be performed from the next EPRB. More specifically, the second ECCE is mapped through the EPRB hopping procedure and the EREG selection procedure. Here, the EPRB hopping procedure starts with EREG # 0 of EPRB # 1 and has the same hopping size (ie, the hopping size used for the initial ECCE / EREG mapping). The EPRB for the second ECCE mapping can be determined through the EPRB hopping procedure. A total of N EREGs for the configuration of the second ECCE can be determined (ie, selected) by selecting one EREG for each determined EPRB. In particular, in this case, each time EPRB hopping is performed, the EREG index selected from the 'corresponding EPRB' (ie, each EPRB determined through the EPRB hopping procedure) can be increased by one. The EREG mapping that constitutes the Mth ECCE (that is, ECCE # (M−1)) can be started from EREG # 0 of EPRB # (M−1). Here, EPRB # (M−1) may correspond to the last EPRB constituting the corresponding EPDCCH set.

  When the first turn (that is, ECCE / EREG mapping for the configuration of ECCE # 0 to ECCE # (M-1)) is completed as described above, all the EPRBs constituting the corresponding EPDCCH set ( For example, EREG (for example, EREG # 0 to EREG # (N-1)) included in each of EPRB # 0 to EPRB # (M-1) is mapped to ECCE # 0 to ECCE # (M-1). Can be used. Then, starting from EREG #N of EPRB # 0, the second round (ie, ECCE / EREG mapping for the configuration of ECCE #M to ECCE # (2M-1)) can be started through the same process. Therefore, ECCE # M to ECCE # (2M-1) can be mapped through the second round.

  As described above, if 16 / N times are performed according to the value of N, the total number (16 / N) × M ECCEs constituting the corresponding EPDCCH set can be mapped.

  The ECCE / EREG mapping method for an arbitrary distributed EPDCCH set according to Embodiment 2-2 can be expressed by the following <Equation 3> and <Equation 4>.

<Formula 3>
i = 0, 1,. . . , (16 / N) × M−1 and N ≧ M,
ECCE # i = {EREG #n (a) of EPRB #m (a)}.

  In Equation 3, a = 0, 1,. . . , N−1, m (a) = (i mod M) + a−M × [{(i mod M) + a} / M], and n (a) = N × [i / M] + a is there. Here, [x] represents a maximum integer not exceeding x.

<Formula 4>
i = 0, 1,. . . , (16 / N) × M−1 and N <M,
ECCE # i = {EREG #n (a) of EPRB #m (a)}.

In Equation 4, a = 0, 1,. . . , N−1, m (a) = (i mod M) + (M / N) × a−M × [{(i mod M) + a} / M].
And n (a) = N × [i / M] + a. Here, [x] represents a maximum integer not exceeding x.

  FIG. 13 is an ECCE configuration diagram of the distributed EPDCCH set according to the embodiment 2-2.

  In FIG. 13, the number (“N”) of EREGs constituting the ECCE may be “4” (N = 4), and the index “i” of the ECCE may be “0” (i = 0).

  FIG. 13a shows the configuration of ECCE according to the above-described <Equation 3>. Referring to FIG. 13a, the number (“M”) of EPRBs constituting the EPDCCH set may be ‘2’ (M = 2). If such variable values (for example, N = 4, i = 0, and M = 2) are applied to the above-described <Equation 3>, (i) (for a = 0) m (0) = 0 And n (0) = 0, (ii) (for a = 1) m (1) = 1 and n (1) = 1, and (iii) (for a = 2) m ( 2) = 0 and n (2) = 2, and (iv) (for a = 3) m (3) = 1 and n (3) = 3. Accordingly, ECCE # 0 may be {EREG # 0 of EPRB # 0, EREG # 1 of EPRB # 1, EREG # 2 of EPRB # 0, EREG # 3 of EPRB # 1}. As shown in FIG. 13a, EREG # 0 may be selected from EPRB # 0 and EREG # 1 may be selected from EPRB # 1. Thereafter, EPRB # 0 to EREG # 2 can be selected, and EPRB # 1 to EREG # 3 can be selected. ECCE # 0 may be configured by the selected EREG.

  FIG. 13 b shows the configuration of ECCE according to the above-described <Equation 4>. Referring to FIG. 13b, the number (“M”) of EPRBs constituting the EPDCCH set is “8” (M = 8). When such variable values (for example, N = 4, i = 0, and M = 8) are applied to the above-described <Equation 4>, (i) (for a = 0) m (0) = 0 And n (0) = 0, (ii) m (1) = 2 and n (1) = 1 (for a = 1), and (iii) m (for a = 2) 2) = 4 and n (2) = 2, and (iv) (for a = 3) m (3) = 6 and n (3) = 3. Accordingly, ECCE # 0 may be {EREG # 0 of EPRB # 0, EREG # 1 of EPRB # 2, EREG # 2 of EPRB # 4, EREG # 3 of EPRB # 6}. In other words, as shown in FIG. 13b, (i) ERB # 0 is selected from EPRB # 0, (ii) EREG # 1 is selected from EPRB # 1, and (iii) EREG # 2 is selected from EPRB # 4 (Iv) EREG # 3 can be selected from EPRB # 6. ECCE # 0 may be configured by the selected EREG.

Embodiment 2-3

  Similar to embodiment 2-2 above, a total of N EREGs can be selected and mapped by selecting one EREG from each of the EPRBs determined through EPRB hopping. However, the EREG selection / mapping is different from the embodiment 2-2, and instead of increasing the EREG index by 1 each time EPRB hops, the EREG index is increased by 16 / N by the above-mentioned 'N' value. You can select and carry out. That is, if the distributed EPDCCH set includes M EPRBs (for example, EPRB # 0 to EPRB # (M-1)), the EPRB for EREG selection (that is, the EPRB for which EREG is selected) is M pieces. Of the EPRBs, it can be mapped (ie, determined) through an EPRB hopping procedure. Here, the EPRB hopping procedure may start with EREG # 0 of EPRB # 0 and have a hopping size according to the conditions of the first embodiment. The EREG used to configure the ECCE can be determined by selecting one EREG for each mapped EPRB (ie, selecting one EREG from each of the mapped EPRBs through the EPRB hopping procedure).

At this time, every time the EPRB hopping is performed once, the “corresponding EPRB” (that is, the EREG index selected from each EPRB determined through the EPRB hopping procedure is set one by one as in the embodiment 2-2). However, according to the embodiment 2-3, each time an EPRB hopping is performed once, the corresponding EPR is increased.
The EREG index selected from B can be increased by 16 / N (determined by the N value). Here, 16 / N may be referred to as an EREG hopping size. For example, when the number of EPRBs allocated for the distributed EPDCCH set (“M”) is 8 (ie, M = 8) and the EPDCCH set is configured with normal downlink subframes of normal CP (ie, , N = 4), the EPRB hopping size can be determined as M / N = 2 according to the conditions of the first embodiment. In addition, Embodiment 2-3
ER to select from the EPRBs that make up each ECCE
The EG hopping size can be determined as 16/4 = 4 .

  Therefore, the first ECCE (ie, ECCE # 0) constituting the corresponding EPDCCH set is (i) EREG # 0 of EPRB # 0, (ii) EREG # 4 of EPRB # 2, and (iii) EPRB # 4. It may be composed of EREG # 8 and (iv) EREG # 12 of EPRB # 6. Similarly, the second ECCE (that is, ECCE # 1) constituting the corresponding EPDCCH set is (i) EREG # 0 of EPRB # 1, (ii) EREG # 4 of EPRB # 3, (iii) EPRB #. 5 EREG # 8, and (iv) EPRB # 7 EREG # 12. Thus, the last ECCE of the first turn, ie, the Mth ECCE of the corresponding EPDCCH set (ie, ECCE # (M−1)) is (i) EREG # 0 of EPRB # 7, (Ii) EREG # 4 of EPRB # 1, (iii) EREG # 8 of EPRB # 3, and (iv) EREG # 12 of EPRB # 5. In this example, ECCE # 7 corresponds to ECCE # (M-1).

  When the first round (that is, ECCE / EREG mapping for the configuration of ECCE # 0 to ECCE # (M-1)) is completed as described above, all the EPRBs (for example, EPRB) configuring the corresponding EPDCCH set are completed. Among EREGs included in # 0 to EPRB # (M−1)), there are M (for example, EREGs having EREG indexes corresponding to “[modulo 16 / N” operation value = 0]). , ECCE # 0 to ECCE # (M-1)). Here, EREG having an EREG index corresponding to “[value of“ modulo 16 / N ”= 0” is “modulo 16 / N” (for example, “modulo 4” in this example). When performed on each EREG index, indicates an EREG having an ERGE index corresponding to [modulo operation value = 0]. M may be 8 in this example.

  In the second round (ie, ECCE / EREG mapping for the configuration of ECCE #M to ECCE # (2M-1)), the corresponding ECCE mapping is the (M + 1) th ECCE (ie, ECCE #) in the same way. M), and can end with the 2Mth ECCE (ie, ECCE # (2M-1)). Here, the (M + 1) -th ECCE (that is, ECCE #M) is set to (i) EREG # 1 of EPRB # 0, (ii) EREG # 5 of EPRB # 2, and (iii) EREG # 9 of EPRB # 4. And (iv) can be mapped to EREG # 13 of EPRB # 6. 2M-th ECCE (i.e., ECCE # (2M-1)) is (i) EREG # 1 of EPRB # 7, (ii) EREG # 5 of EPRB # 1, (iii) EREG # 9 of EPRB # 3, And (iv) can be mapped to EREG # 13 of EPRB # 5.

  As described above, if 16 / N times are performed according to the N value, the total number (16 / N) × M ECCEs constituting the corresponding EPDCCH set can be mapped. At this time, if the last EPRB (that is, the largest EPRB) included in the corresponding EPDCCH set is reached before mapping the Nth EREG for configuring a certain ECCE, the first EPRB (that is, the most) EREG mapping can continue to be performed by applying cyclic shifting back to (small EPRB).

  The ECCE / EREG mapping method for the distributed EPDCCH set according to the present embodiment 2-3 can be expressed by the following <Equation 5> and <Equation 6>.

<Formula 5>
i = 0, 1,. . . , (16 / N) × M−1, and for N ≧ M,
ECCE # i = {EREG #n (a) of EPRB #m (a)}.

In <Formula 5>, a = 0, 1,. . . , N-1
m (a) = (i mod M) + a−M × [{(i mod M) + a} / M]
N (a) = N × [i / M] + (16 / N) × a. Here, [x] represents a maximum integer not exceeding x.

<Formula 6>
i = 0, 1,. . . , (16 / N) × M−1, and for N <M,

  ECCE # i = {EREG #n (a) of EPRB #m (a)}.

In Equation 6, a = 0, 1,. . . , N-1
m (a) = (i mod M) + (M / N) × a−M × [{(i mod M) + a} / M]
N (a) = N × [i / M] + (16 / N) × a. Here, [x] represents a maximum integer not exceeding x.

  FIG. 14 shows an ECCE configuration in a distributed EPDCCH set according to the embodiment 2-3.

  In FIG. 14, the number of EREGs constituting the ECCE (“N”) is “4” (N = 4), and “i” (that is, ECCE index #i) corresponding to the ECCE index is “0” (i = 0).

  FIG. 14a shows the configuration of the ECCE according to the above <Formula 5>. Referring to FIG. 14a, the number (“M”) of EPRBs constituting the EPDCCH set is “2” (M = 2). When such variable values (for example, N = 4, i = 0, and M = 2) are applied to the above-described <Equation 5>, (i) (for a = 0) m (0) = 0 And n (0) = 0, (ii) (for a = 1) m (1) = 1 and n (1) = 4, and (iii) (for a = 2) m ( 2) = 0 and n (2) = 8, and (iv) (for a = 3) m (3) = 1 and n (3) = 12. Accordingly, ECCE # 0 may be {EREG # 0 of EPRB # 0, EREG # 4 of EPRB # 1, EREG # 8 of EPRB # 0, EREG # 12 of EPRB # 1}. In other words, as shown in FIG. 14a, EPRB # 0 to EREG # 0 may be selected, and EPRB # 1 to EREG # 4 may be selected. Thereafter, EPRB # 0 to EREG # 8 may be selected, and EPRB # 1 to EREG # 12 may be selected. ECCE # 0 can be configured by the selected EREG.

  FIG. 14 b shows the configuration of the ECCE according to the above <Formula 6>. Referring to FIG. 14B, the number (“M”) of EPRBs constituting the EPDCCH set is “8” (M = 8). When such variable values (for example, N = 4, i = 0, and M = 8) are applied to the above-described <Equation 6>, (i) (for a = 0) m (0) = 0 N (0) = 0, (ii) (for a = 1) m (1) = 2, n (1) = 4 and (iii) (for a = 2) m ( 2) = 4, n (2) = 8, and (iv) (for a = 3) m (3) = 6, n (3) = 12. Accordingly, ECCE # 0 may be {EREG # 0 of EPRB # 0, EREG # 4 of EPRB # 2, EREG # 8 of EPRB # 4, EREG # 12 of EPRB # 6}. In other words, as shown in FIG. 14b, (i) EPRB # 0 to EREG # 0 are selected, (ii) EPRB # 2 to EREG # 4 are selected, and (iii) EPRB # 4 to EREG # 8 is selected. (Iv) EPRB # 6 to EREG # 12 may be selected. ECCE # 0 can be configured by the selected EREG.

  As described above, among the resource elements (RE) constituting the EREG, there may be an RE that cannot be used for EPDCCH transfer due to the size of the legacy PDCCH control region and the presence of a reference signal (for example, CRS). Therefore, there may be an imbalance in the number of REs that can be used for EPDCCH transmission per EREG. When the ECCE is configured according to the embodiment 2-2 and the embodiment 2-3, the number of REs that can be used for each ECCE will be described in more detail.

  If the size of the legacy PDCCH is '2' OFDM symbol, the number of REs that can be used may be as described in Table 3 above.

  In such a case, the ECCE can be configured while increasing the EREG index (that is, the EREG index to be selected from the corresponding EPRB) by ‘1’ according to the embodiment 2-2. Table 4 below may indicate the number of REs that can be used per ECCE when ECCE is configured according to Embodiment 2-2.

  Referring to Table 4, in the case of one transfer antenna port (“1 Tx CRS”), an ECCE composed of EREGs from EREG # 0 to EREG # 3 includes 25 REs that can be used. The ECCE composed of EREGs EREG # 12 to EREG # 15 includes 31 REs that can be used. Therefore, the difference in the number of REs that can be used between two ECCEs can be six.

  Similarly, when the legacy PDCCH size is '2' OFDM symbol, Table 5 below may indicate the number of REs that can be used by the ECCE in which the ECCE is configured according to Embodiment 2-3.

  Referring to Table 5, in the case of one transfer antenna port (“1 Tx CRS”), an ECCE composed of EREG # 0, EREG # 4, EREG # 8, and EREG # 12 can be used. It can contain 28 REs. An ECCE composed of EREG # 1, EREG # 5, EREG # 9, and EREG # 13 may include 29 REs that can be used. Thus, the difference in the number of REs that can be used between two ECCEs can be one. The difference (for example, 1) in the number of usable REs between the ECCEs according to the embodiment 2-3 is smaller than the difference (for example, 6) in the number of usable REs between the ECCEs according to the embodiment 2-2. There can be. In addition, the number of REs that can be used during ECCE configured according to Embodiment 2-3 for two transfer antenna ports (“2Tx CRS”) and four transfer antenna ports (“4Tx CRS”). The difference between can be '0'.

  The embodiment in which the first embodiment is combined with the second embodiment has been described. However, the present embodiment is not limited to this. Further, the embodiment described in the second embodiment may be independent of the first embodiment.

  For example, according to the embodiment 2-1, the ECCE can be configured by EREGs having the same index. In the case of an EPDCCH set composed of 8 EPRBs, one ECCE corresponds to an EREG (for example, EREG # 0) having the same index in EPRB # 0, EPRB # 2, EPRB # 4, and EPRB # 6. EREG) can be selected and configured. However, Embodiment 2-1 may be independent of Embodiment 1. Therefore, in this case, one ECCE corresponds to an EREG (for example, EREG # 0) having the same index in four consecutive EPRBs (for example, EPRB # 0, EPRB # 1, EPRB # 2, EPRB # 3). EREG) can be selected and configured.

  Other examples related to Embodiment 2 independent of Embodiment 1 are described below. According to the embodiment 2-2, one ECCE can be configured by continuous index EREGs (for example, EREG # 0, EREG # 1, EREG # 2, EREG # 3). In the case of an EPDCCH set composed of two EPRBs, (i) EPRB # 0 to EREG # 0 are selected, (ii) EPRB # 1 to EREG # 1 are selected, and (iii) EPRB # 0 to EREG # 2 (Iv) EPRB # 1 to EREG # 3 can be selected and one ECCE can be configured. However, Embodiment 2-2 may be independent of Embodiment 1. In this case, (i) ERB # 0 is selected from EPRB # 0, and (ii) EREG # 1, EREG # 2, and EREG # 3 are selected from EPRB # 1, and one ECCE can be configured.

  Similarly, Embodiment 2-3 may be independent of Embodiment 1. More specifically, ECCE can be configured by selecting EREG while sequentially increasing the EREG index by 16 / N without hopping EPRB. For example, in an EPDCCH set composed of two EPRBs, (i) EPRG # 0 to EREG # 0, EREG # 4, EREG # 8 are selected, and (ii) EPRB # 1 to EREG # 12 are selected and 1 Two ECCEs can be configured.

  As described above, Embodiment 1 and Embodiment 2 can provide an ECCE / EREG mapping method in a distributed EPDCCH set. In Embodiment 2-1, the ECCE / EREG mapping function can be defined by <Equation 1> and <Equation 2>. In the embodiment 2-2, the ECCE / EREG mapping function can be defined by <Equation 3> and <Equation 4>. In Embodiment 2-3, the ECCE / EREG mapping function can be defined by <Equation 5> and <Equation 6>. However, <Equation 1> to <Equation 6> represent exemplary functional equations reflecting the respective embodiments, and are based on the concepts of Embodiment 2-1, Embodiment 2-2, and Embodiment 2-3. It can be expressed by other types of functional mathematical expressions.

  FIG. 15 is a flowchart illustrating a method for transferring transmission / reception point control information according to at least one embodiment.

  Referring to FIG. 15, a transmission / reception point can transfer control information to a user terminal through a data area of a pair of two or more physical resource blocks (PRB) in a subframe. In step S1510, the transmit / receive point may configure (or form) improved control channel elements (ECCEs) (or may be described as allocating ECCE). Here, the resource element (RE) of each pair of two or more PRBs uses 16 numbers (eg, 0, 1, 2,..., 15) as frequency priority schemes (ie, frequency is given priority first). Then, it can be indexed repeatedly by the time method). Resource elements (REs) having the same index can be included in the same enhanced resource element group (EREG). Each ECCE may include an EREG (eg, 4 or 8 EREGs) corresponding to an EREG having the same modulo value. More specifically, in step S1510, each of the ECCEs is (i) four EREGs with different indexes having the same remainder (eg, 0, 1, 2, or 3) divided by 4, or (ii) 2 Can be composed of 8 EREGs with different indexes (for example, 0 or 1) that are different from each other.

  In step S1510, the EREGs constituting the ECCE can be positioned in pairs in two or more PRBs.

  For the example of the index assigned to the PRB pair, the contents described above with reference to FIGS. 4 to 9 can be referred to. 4 and 7, EREG can be numbered (i.e., indexed) by a frequency priority method (i.e., frequency is given priority first, and then time is given). As shown in FIG. 4, indexing can be performed using symbol-based cyclic shift. More specifically, the resource element (RE) indicated by “400” in the first symbol is indexed as 11 (ie, index 11), and the RE indicated by adjacent “410” in the second symbol is 12 consecutive. (Ie, index 12) can be indexed. On the other hand, as in the embodiment shown in FIG. 7, indexing can be performed without symbol-based cyclic shift. Therefore, in this case, as shown in FIG. 7, the resole element (RE) indicated by “700” of the first symbol is indexed as 11 (that is, index 11) and is assigned by “710” of the second symbol. The indicated RE can be indexed continuously as 12 (index 12). An RE indexed as 12 (“710”) is not adjacent to an RE indexed as 11 (“700”).

  The transmission / reception points are (i) EREG corresponding to different indexes having the same remainder (for example, 0, 1, 2, or 3) divided by 4, or (ii) remainder (for example, 0 or 1) divided by 2 ECCE can be configured using EREGs corresponding to the same different indexes.

  For example, the ECCE can be configured with EREGs corresponding to different indexes having the same remainder (for example, 0, 1, 2, or 3) divided by 4. More specifically, EREG # 0, EREG # 4, EREG # 8, and EREG # 12 can constitute one ECCE. One other ECCE can be configured by EREG # 1, EREG # 5, EREG # 9, and EREG # 13. One other ECCE can be configured by EREG # 2, EREG # 6, EREG # 10, and EREG # 14. Other ECCEs can be configured by EREG # 3, EREG # 7, EREG # 11, and EREG # 15. Further, the EREG index groups corresponding to the ECCEs are {0, 4, 8, 12}, {1, 5, 9, 13}, {2, 6, 10, 14}, or {3, 7, 11, 15 }.

  In another embodiment, when an ECCE is configured with EREGs corresponding to different indexes having the same remainder (for example, 0 or 1) divided by 2, EREG # 0, EREG # 2, EREG # 4, EREG # 6 , EREG # 8, EREG # 10, EREG # 12, and EREG # 14 can constitute one ECCE. EREG # 1, EREG # 3, EREG # 5, EREG # 7, EREG # 9, EREG # 11, EREG # 13, and EREG # 15 can constitute another ECCE. Moreover, the EREG index group corresponding to each ECCE can be expressed as {0, 2, 4, 6, 8, 10, 12, 14} or {1, 3, 5, 7, 9, 11, 13, 15}. .

  The EREGs that make up the ECCE can be located in pairs in more than one PRB. That is, the EPDCCH can be transferred to a distributed type. More specifically, PRB pairs that allocate ECCE at a transmission / reception point may form a distributed type EPDCCH set (ie, a distributed EPDCCH set).

  The transmission / reception points can configure (or assign) ECCE by distributing EREGs to pairs of PRBs so that frequency diversity gain is maximized. Such an ECCE configuration method can be embodied according to the first embodiment, but is not limited thereto.

  Referring to FIG. 11 again, the transmission / reception point configures the ECCE by selecting EREG at EPRB # 2, EPRB # 4, and EPRB # 6 while hopping two PRBs from EPRB # 0 by eight PRB pairs. can do. The transmission / reception point can configure (assign) the ECCE using the EREG of the PRRB pair (for example, EPRB # 0, EPRB # 2, EPRB # 4, and EPRB # 6) determined by the hopping procedure. More specifically, as described above, a transmission / reception point can be configured as one ECCE with (i) EREGs corresponding to different indexes having the same remainder when divided by 4, or (ii) divided by 2. An ECCE can be configured with EREGs corresponding to different indexes having the same remainder.

  More specifically, EPRB # 0 to EREG # 0 may be selected, EPRB # 2 to EREG # 4 may be selected, EPRB # 4 to EREG # 8 may be selected, and EPRB # 6 to EREG # 12 may be selected. The selected EREG can constitute an ECCE. In another embodiment, (i) select EPRB # 0 to EREG # 12, (ii) select EPRB # 2 to EREG # 8, (iii) select EPRB # 4 to EREG # 4, and (iv ) The ECCE can be configured by selecting EREG # 0 from EPRB # 6.

  The EREG index is [0, 1, 2,. . . , 15], (i) a combination of EREGs corresponding to different indexes having the same remainder divided by 4, or (ii) EREGs corresponding to different indexes having the same remainder divided by 2. The combinations can be limited. Considering such a combination, the EREG index (EREG index group) assigned to ECCE is {0, 4, 8, 12}, {1, 5, 9, 13}, {2, 6, 10, 14 } And {3, 7, 11, 15}. Instead, the EREG index assigned to ECCE is {0, 2, 4, 6, 8, 10, 12, 14} and {1, 3, 5, 7, 9, 11, 13, 15}. There can be one.

  Referring again to FIG. 15, in step S1520, the transmission / reception point can transfer control information to the user terminal through at least one configured ECCE.

  Here, the control information can be transferred via the EPDCCH that is a control channel defined in the data area 220. An EPDCCH can be assigned to at least one ECCE in a PRB pair.

  FIG. 16 is a flowchart for a method of receiving control information of a user terminal according to another embodiment.

  Referring to FIG. 16, a user terminal can receive control information from a transmission / reception point through a data region of two or more PRB pairs in a subframe.

  In step S1610, the user terminal can receive a radio signal (which can be referred to as a “radio signal”) through at least one ECCE. Here, in each of the two or more PRB pairs, the resource element (RE) uses 16 numbers (for example, 0, 1, 2,..., 15) as frequency priority schemes (that is, frequency is given priority first). Can be indexed repeatedly according to the time system. Resource elements (REs) having the same index can be included in the same EREG. Each of the at least one ECCE may include an EREG that corresponds to an EREG having the same modulo value. More specifically, each of the at least one ECCE is (i) four EREGs with different indices that are the same as the remainder (eg, 0, 1, 2, or 3) divided by 4, or (ii) 2 The remainder (for example, 0 or 1) can be composed of eight EREGs having the same different index. In step S1620, the user terminal can obtain control information from the received radio signal.

  In step S1610, the EREGs forming the ECCE can be positioned in two or more PRB pairs.

  The example of the index assigned to the PRB pair can refer to the contents described above with reference to FIGS. 4 and 7, EREG can be numbered (that is, indexed) by a frequency priority method (that is, frequency is given priority first, and then time is given). . In the embodiment illustrated in FIG. 4, the symbol-based cyclic shift can be used to perform indexing. More specifically, as shown in FIG. 4, the resource element (RE) indicated by “400” in the first symbol is indexed as 11 (ie, index 11) and then indicated by “410” in the second symbol. Adjacent REs can be indexed consecutively as 12 (ie, index 12). On the other hand, as shown in FIG. 7, indexing can be performed without a symbol-based cyclic shift. Therefore, in this case, after the resource element (RE) indicated by “700” of the first symbol is indexed as 11 (that is, index 11), the RE indicated by “710” of the second symbol is continuous. 12 (ie, index 12). The RE indexed as 12 (“710”) is not adjacent to the RE indexed as 11 (“700”).

  The ECCE is (i) EREG corresponding to different indexes having the same remainder divided by 4 (for example, 0, 1, 2, or 3), or (ii) the remainder divided by 2 (for example, 0 or 1). Can be composed of EREGs corresponding to the same different indexes. In other words, such an EREG may be allocated for ECCE configuration.

  For example, the ECCE can be configured with EREGs corresponding to different indexes having the same remainder (for example, 0, 1, 2, or 3) divided by 4. More specifically, EREG # 0, EREG # 4, EREG # 8, and EREG # 12 can constitute one ECCE. One other ECCE can be configured by EREG # 1, EREG # 5, EREG # 9, and EREG # 13. One other ECCE can be configured by EREG # 2, EREG # 6, EREG # 10, and EREG # 14. Other ECCEs can be configured by EREG # 3, REG # 7, EREG # 11, and EREG # 15. Further, the EREG index group corresponding to each ECCE is {0, 4, 8, 12}, {1, 5, 9, 13}, {2, 6, 10, 14}, or {3, 7, 11, 15 }.

  In another embodiment, when the ECCE is configured with EREGs corresponding to different indexes having the same remainder (for example, 0 or 1) divided by 2, EREG # 0, EREG # 2, EREG # 4, EREG # 6 , EREG # 8, EREG # 10, EREG # 12, and EREG # 14 can constitute one ECCE. EREG # 1, EREG # 3, EREG # 5, EREG # 7, EREG # 9, EREG # 11, EREG # 13, and EREG # 15 can constitute another ECCE. Also, the EREG index group corresponding to each ECCE can be expressed as {0, 2, 4, 6, 8, 10, 12, 14} or {1, 3, 5, 7, 9, 11, 13, 15}.

  The EREGs that make up the ECCE can be located in two or more PRB pairs. That is, the EPDCCH can be transferred to a distributed type. A pair of PRBs to which ECCE is allocated at a transmission / reception point can form a distributed type EPDCCH set (that is, a distributed EPDCCH set).

  An ECCE can be configured (or allocated) by distributing EREGs to PRB pairs so that a frequency diversity gain is maximized. Such an ECCE configuration method can be embodied according to the first embodiment, but is not limited thereto.

  Referring again to FIG. 11, ECCE can be configured by selecting EREGs at EPRB # 2, EPRB # 4, and EPRB # 6 while hopping two PRBs from EPRB # 0 in eight PRB pairs. The ECCE can be composed of a 'PRB pair determined by a hopping procedure' (eg, EPRB # 0, EPRB # 2, EPRB # 4, and EPRB # 6). More specifically, as described above, ECCE corresponds to (i) EREG corresponding to different indexes having the same remainder divided by 4 or (ii) corresponding to different indexes having the same remainder divided by 2. EREG to be selected can be configured.

  More specifically, EPRB # 0 to EREG # 0 may be selected, EPRB # 2 to EREG # 4 may be selected, EPRB # 4 to EREG # 8 may be selected, and EPRB # 6 to EREG # 12 may be selected. The selected EREG can constitute an ECCE. In another embodiment, (i) select EPRB # 0 to EREG # 12, (ii) select EPRB # 2 to EREG # 8, (iii) select EPRB # 4 to EREG # 4, and (iv ) The ECCE can be configured by selecting EREG # 0 from EPRB # 6.

  The EREG index is [0, 1, 2,. . . , 15], (i) a combination of EREGs corresponding to different indexes having the same remainder divided by 4, or (ii) EREGs corresponding to different indexes having the same remainder divided by 2. The combinations can be limited. Considering such a combination, the EREG index (ie, EREG index group) assigned to the ECCE is {0, 4, 8, 12}, {1, 5, 9, 13}, {2, 6, 10, 14} and {3, 7, 11, 15}. Instead, the EREG index assigned to ECCE is 1 of {0, 2, 4, 6, 8, 10, 12, 14} and {1, 3, 5, 7, 9, 11, 13, 15}. Can be one.

  Referring also to FIG. 16, in step S1620, the user terminal can obtain control information.

  FIG. 17 is a diagram illustrating a configuration of a transmission / reception point according to some embodiments.

  Referring to FIG. 17, a transmission / reception point 1700 according to the present embodiment can transfer control information to a user terminal through a data region of two or more PRB pairs in a subframe. The transmission / reception point 1700 according to the present embodiment may include a control unit 1710, a transmission unit 1720, and a reception unit 1730.

  The control unit 1710 can configure (or generate) ECCE (or “allocated ECCE” hereinafter). More specifically, the resource element (RE) in each of two or more PRB pairs is frequency-prioritized using 16 numbers (eg, 0, 1, 2,..., 15) (ie, Indexing can be repeated by frequency first) and then by time. REs having the same index can be included in the same enhanced resource element group (EREG). Each ECCE may include an EREG (eg, 4 or 8 EREG) corresponding to an EREG index having the same modulo value. More specifically, the control unit 1710 (i) a remainder obtained by dividing by 4 (for example, 0, 1, 2, or 3) is different from the four EREGs having the same index, or (ii) a remainder obtained by dividing by 2. (For example, 0 or 1) can be composed of eight EREGs having the same different index.

  The control unit 1710 can control the “ECCE configuration” (or ECCE allocation) so that the EREGs configuring the ECCE are located in a pair of two or more PRBs. That is, the EPDCCH can be transferred to a distributed type. More specifically, PRB pairs to which ECCE is allocated at the transmission / reception point 1700 can form a distributed type EPDCCH set (that is, a distributed PDCCH set).

  The EREG index is [0, 1, 2,. . . , 15], (i) a combination of EREGs corresponding to different indexes having the same remainder divided by 4, or (ii) EREGs corresponding to different indexes having the same remainder divided by 2. The combinations can be limited. Considering such a combination, the EREG index (sometimes referred to as “EREG index group”) assigned to ECCE is {0, 4, 8, 12}, {1, 5, 9, 13}, {2 , 6, 10, 14} and {3, 7, 11, 15}. Instead, the EREG index group assigned to ECCE is {0, 2, 4, 6, 8, 10, 12, 14} and {1, 3, 5, 7, 9, 11, 13, 15}. Can be one of the following.

  In addition, the controller 1710 controls the operation of the transmission / reception point 1700 according to a method of performing ECCE / EREG mapping for EPDCCH transfer and / or a method of performing ECCE indexing on a certain distributed EPDCCH set.

  The transmission unit 1720 transfers control information to the user terminal through at least one ECCE.

  The transmission unit 1720 and the reception unit 1730 can transmit and receive signals, messages, data, and information necessary for performing the above-described embodiment in association with the user terminal.

  FIG. 18 is a diagram illustrating a configuration of a user terminal according to some embodiments.

  Referring to FIG. 18, the user terminal 1800 according to the present embodiment can receive control information from a transmission / reception point (eg, transmission / reception point 1700) through a data region of two or more PRB pairs in a subframe. User terminal 1800 can include a receiving unit 1810, a control unit 1820, and a transmitting unit 1830.

  The receiving unit 1810 can receive a radio signal through at least one ECCE. Here, in each of the two or more PRB pairs, the resource element (RE) uses 16 numbers (for example, 0, 1, 2,..., 15) and uses a frequency priority scheme (ie, frequency). Indexing can be performed repeatedly according to the time system). Resource elements (REs) having the same index can be included in the same EREG. Each of the at least one ECCE includes EREGs corresponding to EREG indexes having the same modulo value. More specifically, each of the at least one ECCE is (i) four EREGs with different indices that are the same as the remainder (eg, 0, 1, 2, or 3) divided by 4, or (ii) 2 The remainder (for example, 0 or 1) can be composed of eight EREGs having the same different index.

  The EREGs that form the ECCE can be located in pairs in more than one PRB. More specifically, a pair of PRBs to which ECCE is allocated at the transmission / reception point 1700 can form a distributed type EPDCCH set (that is, a distributed PDCCH set).

  The EREG index is [0, 1, 2,. . . , 15], (i) a combination of EREGs corresponding to different indexes having the same remainder divided by 4, or (ii) EREGs corresponding to different indexes having the same remainder divided by 2. The combinations can be limited. Looking at such combinations, the EREG index (ie, “EREG index group”) assigned to the ECCE is {0, 4, 8, 12}, {1, 5, 9, 13}, {2, 6 , 10, 14} and {3, 7, 11, 15}. Instead, the EREG index groups assigned to ECCE are {0, 2, 4, 6, 8, 10, 12, 14} and {1, 3, 5, 7, 9, 11, 13, 15}. There can be one.

  The control unit 1820 acquires control information from the received radio signal. In addition, the control unit 1820 controls processing necessary for implementing the above-described embodiment (that is, processing of the user terminal 1800). In more detail, the controller 1820 controls the operation of the user terminal 1800 according to a method of performing ECCE / EREG mapping for EPDCCH transfer and / or a method of performing ECCE indexing in an arbitrary distributed EPDCCH set.

  The reception unit 1810 and the transmission unit 1830 can transmit and receive signals, messages, data, and information necessary for performing the above-described embodiment in association with transmission / reception points.

  Although the technical standard contents referred to in the above-described embodiments have been omitted for the sake of brevity, the related contents of the technical standards can form part of the present specification. Therefore, addition of standard related content to the specification and / or claims should be construed as being included within the scope of the present invention.

  More particularly, the included document may form part of the present specification with a portion of the published document. Therefore, addition of standard related content and part of standard documents to the present specification and / or claims should be construed as falling within the scope of the present invention.

  The above description is merely illustrative of the technical idea of the present invention, and various modifications, changes, and substitutions are possible without departing from the essential characteristics of the present invention. Therefore, the embodiments disclosed in the present invention are not intended to limit the technical idea of the present invention, but are for explanation, and the scope of the technical idea of the present invention is limited to such an embodiment. It is not a thing. The protection scope of the present invention should be construed in accordance with the claims, and all technical ideas within the equivalent scope should be construed as being included in the scope of the right of the present invention.

References to other applications

  This patent application is filed in Korean Patent Application No. 10-2012-0103584 filed in Korea on September 18, 2012, and in Japanese Patent Application No. 10-2012-0145368 filed in Korea on December 13, 2012. In contrast, 35U. S. C§119 (a) claims priority, all of which is incorporated by reference into this patent application.

Claims (20)

A method of transferring control information at a transmission / reception point to a user terminal through a pair of data areas of two or more physical resource blocks (Physical Resource Blocks (PRB)) in a subframe,
An enhanced control channel element (Enhanced Control Channel Elements (ECCEs)) is formed, and (i) resource elements (Resource Elements (Res)) in each of the two or more PRB pairs include 16 elements according to a frequency priority scheme. (Ii) Resource elements (Res) having the same index are included in the same enhanced resource element group (Enhanced Resource Element Group (EREG)), and (iii) the ECCE each different EREG when dividing by one of the index 4 or 2, 4 or 8 corresponding to different EREG index have the same remainder By weight of EREG, that you transfer the EREG included in each of (iv) the ECCE is located in two or more pairs of PRB, among the ECCE, the control information to the user terminal through at least one Including
When the number of EREGs constituting each of the ECCEs is less than the number of PRB pairs, each of the ECCEs is included in a plurality of PRB pairs selected by hopping at a constant index interval. Configuring the ECCE to be mapped to an EREG. The method of claim 1, wherein the fixed index interval is determined based on the number of EREGs and the number of PRB pairs.   The method of claim 1, wherein the two or more PRB pairs are included in an enhanced physical downlink control channel (EPDCCH) set formed in a distributed manner.   The EREG index groups corresponding to each of the ECCEs are {0, 4, 8, 12}, {1, 5, 9, 13}, {2, 6, 10, 14}, and {3, 7, 11, 15. The method of claim 1, wherein the method is selected as one of 15}.   The EREG index groups corresponding to each of the ECCEs are {0, 2, 4, 6, 8, 10, 12, 14} and {1, 3, 5, 7, 9, 11, 13, 15}. The method of claim 1, selected as one. A method of receiving control information at a user terminal from a transmission / reception point through a pair of data areas of two or more physical resource blocks (Physical Resource Block (PRB)) in a subframe,
Receive radio signals through at least one enhanced control channel element (Enhanced Control Channel Elements (ECCEs)), and (i) a resource element (Resource Elements (Res)) in each of the two or more PRB pairs is a frequency priority scheme. And (ii) resource elements (Res) having the same index are included in the same enhanced resource element group (Enhanced Resource Element Group (EREG)), (Iii) Each of the ECCEs has a different EREG index with the same remainder when dividing a different EREG index by one of 4 or 2. (Iv) the EREG included in each of the ECCEs is located in a pair of two or more PRBs;
Obtaining the control information from the received radio signal ;
When the number of EREGs constituting each of the ECCEs is less than the number of PRB pairs, each of the ECCEs associated with reception of the radio signal is selected by being hopped at a constant index interval. Mapped to an EREG included in a plurality of PRB pairs. The method of claim 6, wherein the constant index interval is determined based on the number of EREGs and the number of PRB pairs .   7. The method of claim 6, wherein the two or more PRB pairs are included in one enhanced physical downlink control channel (EPDCCH) set formed in a distributed manner. The EREG index groups corresponding to each of the ECCEs are {0, 4, 8, 12}, {1, 5, 9, 13}, {2, 6, 10, 14}, and {3, 7, 11, 15. The method of claim 6, wherein the method is selected as one of 15}. The EREG index group corresponding to each of the ECCEs is {0, 2, 4,
6, 8, 10, 12, 14} and 1 of {1, 3, 5, 7, 9, 11, 13, 15}
The method of claim 6, wherein the method is selected as one. A transmission / reception point for transferring control information to a user terminal through a pair of data areas of two or more physical resource blocks (Physical Resource Blocks (PRB)) in a subframe,
It is configured to form enhanced control channel elements (Enhanced Control Channel Elements (ECCEs)), and (i) the resource elements (Resource Elements (Res)) of each of the two or more PRB pairs are 16 according to a frequency priority scheme. (Ii) Resource elements (Res) having the same index are included in the same enhanced resource element group (Enhanced Resource Element Group (EREG)), and (iii) ) each of the ECCE, when dividing by one of the different EREG index 4 or 2, 4 corresponds to a different EREG index have the same remainder or Or (iv) the EREG included in each of the ECCEs is a control unit located in a pair of two or more PRBs, and control information is transmitted to the user through at least one of the ECCEs. A transmission unit for transferring to the terminal,
When the number of EREGs constituting each of the ECCEs is less than the number of pairs of PRBs, the control unit selects a plurality of ECCEs that are selected by being hopped at a constant index interval. A transmission / reception point implemented to configure ECCE to be mapped to EREG included in a PRB pair. The transmission / reception point according to claim 11, wherein the fixed index interval is determined based on the number of EREGs and the number of PRB pairs .   The transmission / reception point according to claim 11, wherein the pair of two or more PRBs are included in one enhanced physical downlink control channel (EPDCCH) set formed in a distributed manner.   The EREG index groups corresponding to each of the ECCEs are {0, 4, 8, 12}, {1, 5, 9, 13}, {2, 6, 10, 14}, and {3, 7, 11, The transmission / reception point according to claim 11, selected as one of 15}.   The EREG index groups corresponding to each of the ECCEs are {0, 2, 4, 6, 8, 10, 12, 14} and {1, 3, 5, 7, 9, 11, 13, 15}. The transmission / reception point according to claim 11, which is selected as one. A user terminal that receives control information from a transmission / reception point through a pair of data areas of two or more physical resource blocks (Physical Resource Blocks (PRB)) in a subframe;
Receive radio signals through at least one enhanced control channel element (Enhanced Control Channel Elements (ECCEs)), and (i) each resource element (Resource Elements (Res)) of the two or more PRB pairs is a frequency priority scheme. And (ii) resource elements (Res) having the same index are included in the same enhanced resource element group (Enhanced Resource Element Group (EREG)), (iii) each of the ECCE is different EREG when dividing by one of the index 4 or 2, pairs different EREG index have the same remainder And (iv) the EREG included in each of the ECCEs obtains the control information from the reception unit located in a pair of two or more PRBs and the received radio signal. and a control unit, only contains the
When the number of EREGs constituting each of the ECCEs is less than the number of PRB pairs, each of the ECCEs associated with reception of the radio signal is selected by being hopped at a constant index interval. A user terminal mapped to an EREG included in a plurality of PRB pairs. The terminal of claim 16, wherein the constant index interval is determined based on the number of EREGs and the number of PRB pairs .   The terminal of claim 16, wherein the two or more PRB pairs are included in one enhanced physical downlink control channel (EPDCCH) set formed in a distributed manner. The EREG index group corresponding to each ECCE is {0, 4, 8, 12
}, {1, 5, 9, 13}, {2, 6, 10, 14}, and {3, 7, 11, 15}, selected as one of the terminals of claim 16. The EREG index group corresponding to each of the ECCEs is {0, 2, 4, 6,
The terminal according to claim 16, selected as one of 8, 10, 12, 14} and {1, 3, 5, 7, 9, 11, 13, 15}.