KR102598083B1 - Method and apparatus for downlink control channel resource element mapping in wireless communication systems - Google Patents

Abstract

The present disclosure relates to a method of operating a terminal for mapping downlink control channel resource elements in a wireless communication system, receiving an EPDCCH PRB from a base station, and NZP-FrequencyDensity set in the NZP CSI-RS included in the received EPDCCH PRB. It includes performing resource element mapping for the received EPDCCH PRB according to the value.

Description

Downlink control channel resource element mapping method and device in a wireless communication system {METHOD AND APPARATUS FOR DOWNLINK CONTROL CHANNEL RESOURCE ELEMENT MAPPING IN WIRELESS COMMUNICATION SYSTEMS}

The present invention relates to a wireless communication system, and more specifically, to a method and device for mapping downlink control channel resource elements.

In order to meet the increasing demand for wireless data traffic following the commercialization of the 4G communication system, efforts are being made to develop an improved 5G communication system or pre-5G communication system. For this reason, the 5G communication system or pre-5G communication system is called a Beyond 4G Network communication system or a Post LTE system. To achieve high data rates, 5G communication systems are being considered for implementation in ultra-high frequency (mmWave) bands (such as the 60-gigabit (70GHz) band). In order to alleviate the path loss of radio waves in the ultra-high frequency band and increase the transmission distance of radio waves, the 5G communication system uses beamforming, massive array multiple input/output (massive MIMO), and full dimension multiple input/output (FD-MIMO). ), array antenna, analog beam-forming, and large scale antenna technologies are being discussed. In addition, to improve the network of the system, the 5G communication system uses advanced small cells, advanced small cells, cloud radio access networks (cloud RAN), and ultra-dense networks. , Device to Device communication (D2D), wireless backhaul, moving network, cooperative communication, CoMP (Coordinated Multi-Points), and interference cancellation. Technology development is underway. In addition, the 5G system uses FQAM (Hybrid FSK and QAM Modulation) and SWSC (Sliding Window Superposition Coding), which are advanced coding modulation (ACM) methods, and advanced access technologies such as FBMC (Filter Bank Multi Carrier) and NOMA. (non-orthogonal multiple access), and SCMA (sparse code multiple access) are being developed.

Meanwhile, the Internet is evolving from a human-centered network where humans create and consume information to an IoT (Internet of Things) network that exchanges and processes information between distributed components such as objects. IoE (Internet of Everything) technology, which combines IoT technology with big data processing technology through connection to cloud servers, etc., is also emerging. In order to implement IoT, technological elements such as sensing technology, wired and wireless communication and network infrastructure, service interface technology, and security technology are required. Recently, sensor networks for connection between things, and machine to machine communication (Machine to Machine) are required to implement IoT. , M2M), and MTC (Machine Type Communication) technologies are being researched. In an IoT environment, intelligent IT (Internet Technology) services that create new value in human life can be provided by collecting and analyzing data generated from connected objects. IoT is used in fields such as smart home, smart building, smart city, smart car or connected car, smart grid, healthcare, smart home appliances, and advanced medical services through the convergence and combination of existing IT (information technology) technology and various industries. It can be applied to .

Accordingly, various attempts are being made to apply the 5G communication system to the IoT network. For example, technologies such as sensor network, Machine to Machine (M2M), and MTC (Machine Type Communication) are being implemented by 5G communication technologies such as beam forming, MIMO, and array antenna. . The application of cloud radio access network (cloud RAN) as the big data processing technology described above can be said to be an example of the convergence of 3eG technology and IoT technology.

As various services can be provided as described above and with the development of mobile communication systems, there is a need for a method to provide these services smoothly.

The disclosed embodiment seeks to provide a method and device that can effectively provide services in a wireless communication system.

A method of operating a terminal for mapping downlink control channel resource elements in a wireless communication system according to some embodiments includes receiving an EPDCCH PRB from a base station; And it may include performing resource element mapping for the EPDCCH PRB according to the NZP-FrequencyDensity value set in the NZP CSI-RS included in the received EPDCCH PRB.

The disclosed embodiment provides a method and device that can effectively provide services in a wireless communication system.

Figure 1 is a diagram showing the basic structure of a time-frequency resource area, which is a radio resource area in LTE, LTE-A, 5G or similar systems according to some embodiments of the present disclosure.
Figure 2 shows a method of allocating PDCCH and EPDCCH (Enhanced PDCCH), which are downlink physical channels on which DCI is transmitted in the frequency-time resource domain, in LTE, LTE-A, 5G or similar systems according to some embodiments of the present disclosure. This is a drawing for explanation.
Figure 3 is a diagram illustrating an EPDCCH resource mapping method according to some embodiments of the present disclosure.
Figures 4 and 5 are diagrams illustrating the search space of EPDCCH of LTE, LTE-A, 5G or similar systems according to some embodiments of the present disclosure.
Figure 6 is a block diagram showing the structure of a terminal according to some embodiments of the present disclosure.
Figure 7 is a block diagram showing the structure of a base station according to some embodiments of the present disclosure.

Hereinafter, embodiments of the present disclosure will be described in detail with reference to the attached drawings. Additionally, in describing the present disclosure, if it is determined that a detailed description of a related known function or configuration may unnecessarily obscure the gist of the present invention, the detailed description will be omitted. In addition, the terms described below are terms defined in consideration of the functions in the present disclosure, and may vary depending on the intention or custom of the user or operator. Therefore, the definition should be made based on the contents throughout this specification.

The advantages and features of the present disclosure and methods for achieving them will become clear by referring to the embodiments described in detail below along with the accompanying drawings. However, the present disclosure is not limited to the embodiments disclosed below and may be implemented in various different forms, and the present embodiments are merely intended to ensure that the disclosure is complete and to provide common knowledge in the technical field to which the present disclosure pertains. It is provided to fully inform those who have the scope of the invention, and the present disclosure is only defined by the scope of the claims. Like reference numerals refer to like elements throughout the specification.

At this time, it will be understood that each block of the processing flow diagrams and combinations of the flow diagram diagrams can be performed by computer program instructions. These computer program instructions can be mounted on a processor of a general-purpose computer, special-purpose computer, or other programmable data processing equipment, so that the instructions performed through the processor of the computer or other programmable data processing equipment are described in the flow chart block(s). It creates the means to perform functions. These computer program instructions may also be stored in computer-usable or computer-readable memory that can be directed to a computer or other programmable data processing equipment to implement a function in a particular manner, so that the computer-usable or computer-readable memory It is also possible to produce manufactured items containing instruction means that perform the functions described in the flowchart block(s). Computer program instructions can also be mounted on a computer or other programmable data processing equipment, so that a series of operational steps are performed on the computer or other programmable data processing equipment to create a process that is executed by the computer, thereby generating a process that is executed by the computer or other programmable data processing equipment. Instructions that perform processing equipment may also provide steps for executing the functions described in the flow diagram block(s).

Additionally, each block may represent a module, segment, or portion of code that includes one or more executable instructions for executing specified logical function(s). Additionally, it should be noted that in some alternative execution examples it is possible for the functions mentioned in the blocks to occur out of order. For example, it is possible for two blocks shown in succession to be performed substantially simultaneously, or it is possible for the blocks to be performed in reverse order depending on the corresponding function.

At this time, the term '~unit' used in this embodiment refers to software or hardware components such as FPGA (Field Programmable Gate Array) or ASIC (Application Specific Integrated Circuit), and '~unit' performs certain roles. do. However, '~part' is not limited to software or hardware. The '~ part' may be configured to reside in an addressable storage medium and may be configured to reproduce on one or more processors. Therefore, as an example, '~ part' refers to components such as software components, object-oriented software components, class components, and task components, processes, functions, properties, and procedures. , subroutines, segments of program code, drivers, firmware, microcode, circuitry, data, databases, data structures, tables, arrays, and variables. The functions provided within the components and 'parts' may be combined into a smaller number of components and 'parts' or may be further separated into additional components and 'parts'. Additionally, components and 'parts' may be implemented to regenerate one or more CPUs within a device or a secure multimedia card. Additionally, in the embodiment, ‘~ part’ may include one or more processors.

In the following description of the present disclosure, if a detailed description of a related known function or configuration is determined to unnecessarily obscure the gist of the present disclosure, the detailed description will be omitted. Hereinafter, embodiments of the present disclosure will be described with reference to the attached drawings.

Terms used in the following description to identify a connection node, terms referring to network entities, terms referring to messages, terms referring to interfaces between network objects, and various identification information. Referring terms, etc. are exemplified for convenience of explanation. Accordingly, the present disclosure is not limited to the terms described below, and other terms referring to objects having equivalent technical meaning may be used.

For convenience of description below, the present disclosure uses terms and names defined in the 3rd Generation Partnership Project Long Term Evolution (3GPP LTE) standard. However, the present disclosure is not limited by the above terms and names, and can be equally applied to systems complying with other standards. In this disclosure, eNB may be used interchangeably with gNB for convenience of explanation. That is, a base station described as an eNB may represent a gNB. Additionally, the term terminal can refer to mobile phones, NB-IoT devices, sensors, as well as other wireless communication devices.

Hereinafter, the base station is the entity that performs resource allocation for the terminal and may be at least one of gNode B, eNode B, Node B, BS (Base Station), wireless access unit, base station controller, or node on the network. A terminal may include a UE (User Equipment), MS (Mobile Station), a cellular phone, a smartphone, a computer, or a multimedia system capable of performing communication functions. Of course, it is not limited to the above examples.

In particular, the present disclosure is applicable to 3GPP NR (5th generation mobile communication standard). In addition, this disclosure provides intelligent services (e.g., smart home, smart building, smart city, smart car or connected car, healthcare, digital education, retail, security and safety-related services) based on 5G communication technology and IoT-related technology. etc.) can be applied. In the present invention, eNB may be used interchangeably with gNB for convenience of explanation. That is, a base station described as an eNB may represent a gNB. Additionally, the term terminal can refer to mobile phones, NB-IoT devices, sensors, as well as other wireless communication devices.

Wireless communication systems have moved away from providing early voice-oriented services to, for example, 3GPP's HSPA (High Speed Packet Access), LTE (Long Term Evolution or E-UTRA (Evolved Universal Terrestrial Radio Access)), and LTE-Advanced. Broadband wireless that provides high-speed, high-quality packet data services such as communication standards such as (LTE-A), LTE-Pro, 3GPP2's High Rate Packet Data (HRPD), UMB (Ultra Mobile Broadband), and IEEE's 802.16e. It is evolving into a communication system.

As a representative example of the broadband wireless communication system, the LTE system uses Orthogonal Frequency Division Multiplexing (OFDM) in the downlink (DL), and Single Carrier Frequency Division Multiplexing (SC-FDMA) in the uplink (UL). Access) method is adopted. Uplink refers to a wireless link in which a terminal (UE (User Equipment) or MS (Mobile Station)) transmits data or control signals to a base station (eNode B, or base station (BS)), and downlink refers to a wireless link in which the base station transmits data or control signals to the base station (eNode B, or base station (BS)). It refers to a wireless link that transmits data or control signals. The above multiple access method usually distinguishes each user's data or control information by allocating and operating the time-frequency resources to carry data or control information for each user so that they do not overlap, that is, orthogonality is established. do.

As a future communication system after LTE, that is, the 5G communication system must be able to freely reflect the various requirements of users and service providers, so services that simultaneously satisfy various requirements must be supported. Services considered for the 5G communication system include enhanced Mobile BroadBand (eMBB), massive Machine Type Communication (mNTC), and Ultra Reliability Low Latency Communication (URLLC). There is.

According to some embodiments, eMBB may aim to provide more improved data transmission rates than those supported by existing LTE, LTE-A, or LTE-Pro. For example, in a 5G communication system, eMBB must be able to provide a peak data rate of 20Gbps in the downlink and 10Gbps in the uplink from the perspective of one base station. In addition, the 5G communication system may need to provide the maximum transmission rate and at the same time provide an increased user perceived data rate. In order to meet these requirements, the 5G communication system may require improvements in various transmission and reception technologies, including more advanced multi-antenna (MIMO; Multi Input Multi Output) transmission technology. In addition, while the current LTE transmits signals using a maximum of 20 MHz transmission bandwidth in the 2 GHz band, the 5G communication system uses a frequency bandwidth wider than 20 MHz in the 3 to 6 GHz or above 6 GHz frequency band, meeting the requirements of the 5G communication system. Data transfer speed can be satisfied.

At the same time, mMTC is being considered to support application services such as Internet of Things (IoT) in 5G communication systems. In order to efficiently provide the Internet of Things, mMTC requires support for access to a large number of terminals within a cell, improved coverage of terminals, improved battery time, and reduced terminal costs. Since the Internet of Things provides communication functions by attaching various sensors and various devices, it must be able to support a large number of terminals (for example, 1,000,000 terminals/km ² ) within a cell. Additionally, due to the nature of the service, terminals supporting mMTC are likely to be located in shaded areas that cannot be covered by cells, such as the basement of a building, so wider coverage may be required compared to other services provided by the 5G communication system. Terminals that support mMTC must be composed of low-cost terminals, and because it is difficult to frequently replace the terminal's battery, a very long battery life time, such as 10 to 15 years, is required.

Lastly, in the case of URLLC, it is a cellular-based wireless communication service used for specific purposes (mission-critical), such as remote control of robots or machinery, industrial automation, It can be used for services such as unmanned aerial vehicles, remote health care, and emergency alerts. Therefore, the communication provided by URLLC may need to provide very low latency (ultra-low latency) and very high reliability (ultra-reliability). For example, a service supporting URLLC must satisfy an air interface latency of less than 0.5 milliseconds and may have a packet error rate of 10 ^-5 or less. Therefore, for services supporting URLLC, the 5G system must provide a smaller Transmit Time Interval (TTI) than other services, and at the same time, a design that requires allocating wide resources in the frequency band to ensure the reliability of the communication link. Specifications may be required.

The three services considered in the above-described 5G communication system, namely eMBB, URLLC, and mMTC, can be multiplexed and transmitted in one system. At this time, different transmission/reception techniques and transmission/reception parameters can be used between services to satisfy the different requirements of each service. However, the above-described mMTC, URLLC, and eMBB are only examples of different service types, and the service types to which this disclosure is applied are not limited to the above-described examples.

In addition, hereinafter, embodiments of the present invention will be described using LTE, LTE-A, LTE Pro or 5G (or NR) systems as an example, but embodiments of the present invention can also be applied to other communication systems with similar technical background or channel type. You can. In addition, the embodiments of the present invention may be applied to other communication systems through some modifications without significantly departing from the scope of the present invention at the discretion of a person with skilled technical knowledge. Downlink and uplink transmission in a wireless communication system To support transmission of channels, related downlink control information (Downlink Control Information, DCI) is required. In conventional LTE, DCI is transmitted through PDCCH (Physical Downlink Control Channel), a separate physical channel through which downlink control information is transmitted. PDCCH is transmitted every subframe across the entire system band. One PDCCH carries one DCI message, and since multiple terminals can be scheduled simultaneously on the downlink and uplink, multiple PDCCHs are transmitted simultaneously within each cell. A cell-specific reference signal (CRS), a cell common reference signal, is used as a reference signal (RS) for decoding of the PDCCH. CRS is an always-on signal transmitted in every subframe across the entire band, and scrambling and resource mapping vary depending on the cell ID (identity). All terminals that monitor the PDCCH estimate the channel using CRS and perform decoding on the PDCCH. Since CRS is a reference signal transmitted in a broadcast manner to all UEs, UE-specific beamforming cannot be used. Therefore, the multi-antenna transmission technique for LTE's PDCCH is limited to open-loop transmission diversity.

As various technologies such as CA (Carrier Aggregation) and CoMP (Coordinated MultiPoint) are supported in conventional LTE, it has become difficult to secure sufficient transmission capacity to transmit downlink control signals using only the previously used PDCCH. Accordingly, in LTE Release 11, EPDCCH (Enhanced PDCCH) was added as a physical channel for transmitting DCI. EPDCCH was designed to satisfy requirements such as increased control channel transmission capacity, frequency axis adjacent cell interference control, frequency-selective scheduling, and coexistence with existing LTE terminals. Since DMRS (Demodulation Reference Signal), a UE-specific reference signal, is used as a reference signal for decoding of EPDCCH, UE-specific beamforming can be used for EPDCCH. Therefore, in the case of EPDCCH, the multi-antenna transmission technique using precoding is supported, and depending on the resource allocation method, the transmission diversity technique using precoder cycling and the MU-MIMO (Multiuser MIMO) transmission technique are supported. Supports.

The EPDCCH described above maps EPDCCH REs by calculating CCE and REG, excluding REs used for other RSs and channels, such as CRS, DMRS, and CSI-RS, in PRBs within the configured band. Meanwhile, in LTE-A Rel-14, as the number of CSI-RS ports increases, CSI-RS density 1/2 and 1/3 RE/RB/port were newly introduced to reduce the CSI-RS transmission burden. Accordingly, it may be possible for the CSI-RS RE pattern to vary for each PRB, and in this case, EPDCCH RE mapping assumes the same RE mapping pattern for all EPDCCH RBs, so there is a problem in which CCE and REG calculations for each RB become ambiguous. This disclosure seeks to provide various methods to solve this problem.

Hereinafter, the frame structure in LTE, LTE-A, 5G or similar systems will be described in more detail with reference to the drawings.

Figure 1 is a diagram showing the basic structure of a time-frequency resource area, which is a radio resource area in LTE, LTE-A, 5G or similar systems according to some embodiments of the present disclosure.

Referring to Figure 1, the horizontal axis represents the time domain and the vertical axis represents the frequency domain. The minimum transmission unit in the time domain is an OFDM symbol. N _symb (102) OFDM symbols are gathered to form one slot (106), and two slots are gathered to form one subframe (105). The length of the slot is 0.5ms, the length of the subframe can be defined as 1.0ms, and the radio frame 114 is a time domain unit consisting of 10 subframes. The minimum transmission unit in the frequency domain is a subcarrier, and the bandwidth of the entire system transmission bandwidth can be composed of a total of N _BW (104) subcarriers. However, these specific numbers may be applied variably depending on the system.

The basic unit of resources in the time-frequency domain is a resource element (112, RE), which can be represented by an OFDM symbol index and a subcarrier index. The resource block 108 (Resource Block, RB or Physical Resource Block, PRB) can be defined as N _symb (102) consecutive OFDM symbols in the time domain and N _RB (110) consecutive subcarriers in the frequency domain. Accordingly, one PRB 108 may be composed of N _symb x N _RB REs 112. A PRB pair is a unit of two PRBs concatenated on the time axis and may be composed of N _symb x 2 x N _RB REs (112).

In general, the minimum transmission unit of data may be a PRB unit. In an LTE system, N _symb = 7 and N _RB = 12, and N _BW and N _RB may be proportional to the bandwidth of the system transmission band. However, these specific numbers may be applied variably depending on the system.

Next, we will explain downlink control information (DCI) in LTE, LTE-A, 5G or similar systems.

In LTE, LTE-A, 5G or similar systems, scheduling information for downlink data or uplink data can be transmitted from the base station to the terminal through downlink control information (DCI). DCI defines various formats, whether it is scheduling information for uplink data (UL grant) or scheduling information for downlink data (DL grant), whether it is compact DCI with a small size of control information, and whether it is a compact DCI using multiple antennas. It can be operated by applying a determined DCI format depending on whether spatial multiplexing is applied, whether it is DCI for power control, etc. For example, DCI format 1, which is scheduling control information (DL grant) for downlink data, may be configured to include at least the following control information.

- Resource allocation type 0/1 flag: Notifies whether the resource allocation method is type 0 or type 1. Type 0 applies the bitmap method to allocate resources in RBG (resource block group) units. The basic unit of scheduling in the LTE system is the RB (resource block) expressed as time and frequency domain resources, and the RBG is composed of a plurality of RBs and becomes the basic unit of scheduling in the type 0 method. Type 1 allows allocation of a specific RB within the RBG.

- Resource block assignment: Notifies the RB allocated to data transmission. The resources represented are determined by system bandwidth and resource allocation method.

- Modulation and coding scheme (MCS): Notifies the modulation method used for data transmission and the size of the transport block, which is the data to be transmitted.

- HARQ process number: Notifies the HARQ process number.

- New data indicator: Notifies whether it is HARQ initial transmission or retransmission.

- Redundancy version: Notifies the redundancy version of HARQ.

- Transmit Power Control (TPC) command for PUCCH (Physical Uplink Control CHannel): Notifies the transmit power control command for PUCCH, an uplink control channel.

DCI can be transmitted through the downlink physical control channel PDCCH or EPDCCH (Enhanced PDCCH) through channel coding and modulation processes.

A CRC (Cyclic Redundancy Check) is attached to the DCI message payload, and the CRC is scrambled with an RNTI (Radio Network Temporary Identifier) corresponding to the terminal's identity. Different RNTIs may be used depending on the purpose of the DCI message, for example, UE-specific data transmission, power control command, or random access response. The RNTI may not be transmitted explicitly but may be transmitted included in the CRC calculation process. When receiving a DCI message transmitted on the PDCCH, the terminal checks the CRC using the allocated RNTI, and if the CRC check result is correct, it can know that the message was sent to the terminal.

Next, the downlink control channel through which DCI is transmitted in LTE, LTE-A, 5G or similar systems will be described with reference to the drawings.

Figure 2 shows a method of allocating PDCCH and EPDCCH (Enhanced PDCCH), which are downlink physical channels on which DCI is transmitted in the frequency-time resource domain, in LTE, LTE-A, 5G or similar systems according to some embodiments of the present disclosure. This is a drawing for explanation.

Referring to FIG. 2, the PDCCH (201) is time-multiplexed with the PDSCH (203), a data transmission channel, and can be transmitted across the entire system bandwidth. The area of the PDCCH 201 can be expressed as the number of OFDM symbols, which can be indicated to the UE by a CFI (Control Format Indicator) transmitted through a PCFICH (Physical Control Format Indicator Channel). By allocating the PDCCH (201) to the OFDM symbol that comes at the beginning of the subframe, the UE can decode the downlink scheduling assignment as quickly as possible, thereby reducing the decoding delay for the DL-SCH (Downlink Shared Channel), that is, the overall downlink Link transmission delay can be reduced. One PDCCH carries one DCI message, and since multiple terminals can be scheduled simultaneously on the downlink and uplink, multiple PDCCHs can be transmitted simultaneously within each cell.

The CRS 204 may be used as a reference signal for decoding the PDCCH 201. The CRS 204 may be transmitted every subframe across the entire band, and scrambling and resource mapping may vary depending on the cell ID (Identity). Since the CRS 204 is a reference signal commonly used by all terminals, terminal-specific beamforming cannot be used. Therefore, the multi-antenna transmission technique for LTE's PDCCH may be limited to open-loop transmission diversity. The number of CRS ports can be implicitly known to the terminal from decoding of the PBCH (Physical Broadcast Channel).

Resource allocation of the PDCCH 201 is based on CCE (Control-Channel Element), and one CCE may be composed of 9 REGs (Resource Element Groups), that is, a total of 36 REs (Resource Elements). The number of CCEs required for a specific PDCCH (201) may be 1, 2, 4, or 8, which may vary depending on the channel coding rate of the DCI message payload. In this way, different numbers of CCEs can be used to implement link adaptation of the PDCCH (201).

The terminal must detect a signal without knowing information about the PDCCH (201), and in LTE, a search space representing a set of CCEs is defined for blind decoding. The search space consists of a plurality of sets at the aggregation level (AL) of each CCE, which is not explicitly signaled but can be implicitly defined through a function and subframe number based on the terminal identity. Within each subframe, the terminal performs decoding on the PDCCH (201) for all possible resource candidates that can be created from CCEs in the set search space, and information declared as valid for the terminal through CRC confirmation. can be processed.

The search space can be classified into a terminal-specific search space and a common search space. A certain group of UEs or all UEs may search the common search space of the PDCCH 201 to receive cell common control information such as dynamic scheduling or paging messages for system information. For example, scheduling allocation information of DL-SCH for transmission of SIB (System Information Block)-1 including cell operator information, etc. can be received by examining the common search space of the PDCCH 201. In addition, UE-specific DCI, such as scheduling information for uplink data and scheduling information for downlink data, may be transmitted through a mode UE-specific search space.

As various technologies such as CA (Carrier Aggregation) and CoMP (Coordinated MultiPoint) are supported in conventional LTE, it has become difficult to secure sufficient transmission capacity to transmit downlink control signals using only the previously used PDCCH. Accordingly, in LTE Release 11, EPDCCH (202) was added as a physical channel for transmitting downlink DCI. EPDCCH was designed to satisfy the following requirements.

- Increased control channel transmission capacity

- Frequency axis adjacent cell interference control

- Frequency-selective scheduling

- MBSFN subframe support

- Coexistence with existing LTE terminals

Referring to FIG. 2, the EPDCCH (202) can be frequency-multiplexed and transmitted with the PDSCH (203). The base station can appropriately allocate resources of the EPDCCH (202) and PDSCH (203) through scheduling, thereby effectively supporting coexistence with data transmission for existing LTE terminals. However, since the EPDCCH 202 is allocated and transmitted throughout one subframe on the time axis, there is a problem that there is a loss in terms of transmission delay time. A plurality of EPDCCHs 202 constitute one EPDCCH set 206, and allocation of the EPDCCH 202 set may be made in units of PRB (Physical Resource Block) pairs. Location information for the EPDCCH set 206 can be set UE-specifically, and this can be signaled through RRC (Remote Radio Control). Up to two EPDCCH sets 206 can be configured for each terminal, and one EPDCCH set 206 can be multiplexed and configured simultaneously for different terminals.

In EPDCCH 202, DMRS (Demodulation Reference Signal, 205) can be used as an RS for decoding. The DMRS 205 of the EPDCCH 202 uses the same pattern as the PDSCH 203. However, unlike the PDSCH (203), the DMRS (205) in the EPDCCH (202) can support up to four antenna ports, {107, 108, 109, 110}. The DMRS 205 of the EPDCCH 202 is transmitted only in the corresponding PRB where the EPDCCH 202 is transmitted. In other words, if the EPDCCH (202) is not mapped and transmitted in a PRB, the DMRS (205) for decoding the EPDCCH (202) in that PRB is not transmitted.

The RS sequence for the DMRS 205 of the EPDCCH 202 can be defined as follows.

[Formula 1]

The initial sequence used to generate the pseudo-random sequence c(n) in [Equation 1] can be defined as follows.

[Formula 2]

는 하기와 같이 단말-특정의 상위계층 시그널링을 통해 설정될 수 있다.In [Formula 2]

Can be set through terminal-specific upper layer signaling as follows.

값(즉, i={0, 1})이 설정될 수 있다. 전술한 바와 같이 DMRS(205)는 단말-특정의 시퀀스가 사용될 수 있고, 이를 통해 단말 별 DMRS(205)를 구별할 수 있다. EPDCCH(202)에 대한 프리코딩은 기지국이 설정할 수 있고, 단말-특정 빔포밍을 사용할 수 있다. DMRS(205)를 통해 단말들은 어떠한 프리코딩이 사용되었는지 알지 못해도 EPDCCH(202)에 대한 디코딩을 수행할 수 있다.For the two EPDCCH sets (206) that can be set for each terminal, two

A value (i.e., i={0, 1}) may be set. As described above, the DMRS 205 may use a terminal-specific sequence, through which the DMRS 205 for each terminal can be distinguished. Precoding for EPDCCH 202 can be set by the base station, and UE-specific beamforming can be used. Through the DMRS 205, UEs can perform decoding on the EPDCCH 202 without knowing what precoding was used.

The port configuration information of the DMRS (205) may vary depending on the EPDCCH (202) transmission method. In the case of the localized transmission method, the antenna port corresponding to one EPDCCH (202) can be randomly selected based on the ID of the terminal. When different terminals share the same time/frequency resources, that is, when multiuser MIMO (Multiuser MIMO) transmission is used, a DMRS antenna port may be allocated to each terminal. Alternatively, the DMRS 205 can be shared and transmitted. In this case, it can be distinguished by the DMRS 205 scrambling sequence set as upper layer signaling. In the case of the distributed transmission method, up to two antenna ports of the DMRS 205 can be supported, and a diversity technique of the precoder cycling method can be supported. The DMRS 205 can be shared for all REs transmitted within one PRB pair.

Next, the EPDCCH resource mapping method will be explained with reference to the drawings.

Figure 3 is a diagram illustrating an EPDCCH resource mapping method according to some embodiments of the present disclosure.

In Figure 3, one PRB pair is shown as an example. There may be 16 EREGs (Enhanced REGs, 301) within one PRB. REs in one PRB pair are {0,1,2,… It can be mapped to the EREG (301) index corresponding to ,15}. At this time, the RE to which the DMRS 303 is mapped is excluded from numbering. A set of REs corresponding to each index constitutes one EREG (301). For example, in the PRB pair shown in FIG. 3, there are a total of 9 REs (307) mapped to index 0, and these 9 REs constitute ERGE0 (304). Soon, REs numbered with each index x (x={0,1,2,…,15}) constitute EREGx. In explaining the present disclosure, for convenience, the EREG 301 existing in one PRB pair will be illustrated and described using a logical mapping method as 305 in FIG. 3.

Resource allocation of EPDCCH is based on ECCE (Enhanced CCE, 302), and one ECCE (302) may consist of 4 or 8 EREGs (301). The number of EREGs 301 per ECCE 302 may vary depending on CP length and subframe setting information. Figure 3 shows an example in which four EREGs 301 constitute one ECCE 302. More specifically, at 305 in FIG. 3, EREG0, EREG4, EREG8, and EREG12 are assigned to ECCE0, EREG1, EREG5, EREG9, and EREG13 are assigned to ECCE1, EREG2, EREG6, EREG10, and EREG14 are assigned to ECCE2, and EREG3, EREG7, EREG11, and EREG15 maps to ECCE3, respectively. Therefore, when four EREGs 301 constitute one ECCE 302, a total of four ECCEs 302 may exist within one PRB pair. In explaining the present disclosure, for convenience, the ECCE 302 existing in one PRB pair will be illustrated and described using a logical mapping method as 306 in FIG. 3.

EPDCCH transmission method can be classified into localized or distributed transmission depending on the mapping method between ECCE (302) and EREG (301). In the localized transmission method, all EREGs 301 constituting the ECCE 302 may exist within the same PRB pair. On the other hand, in the distributed transmission method, EREGs 301 constituting the ECCE 302 may exist in different PRB pairs among multiple PRB pairs set for EPDCCH transmission.

Next, we will explain the search space in EPDCCH.

EPDCCH can only support UE-specific search space. The search space for EPDCCH can be defined as follows.

According to the definition of the EPDCCH search space described above, the search space is a set of candidate control channels consisting of ECCEs that the terminal must attempt to decode on a given aggregation level, and the EPDCCH is an aggregation of 1, 2, 4, 8, 16, and 32. It can have levels. Since there are several aggregation levels that bundle multiple ECCEs into one bundle, the terminal can have multiple search spaces depending on the aggregation level. The aggregation level of EPDCCH can be 1, 2, 4, 8, 16, and 32, which is based on system parameters such as CP length, subframe settings, EPDCCH format, localized/distributed transmission method, and total number of ECCEs. It can be determined by . An example of the number of PDCCH candidates that the UE must monitor in the search space defined according to the aggregation level in EPDCCH may be shown in [Table 1] below.

[Table 1]

는 EPDCCH set p에 대해 설정된 PRB pair의 수를 의미한다. [표 1]의 Case 3은 각각 서브프레임 구조, DCI 포맷, 시스템 대역폭 등의 시스템 파라미터로 결정되는 시나리오를 의미할 수 있다. 이에 대한 자세한 내용은 본 개시를 설명함에 있어서 불필요하므로 생략하도록 한다. [표 1]에 대해 하나의 예를 들어 설명하면, EPDCCH set이 4개의 PRB pair로 구성되어 있을 경우 aggregation level 1, 2, 4, 8에 대 각각 6, 6, 2, 2개의 EPDCCH 후보군들이 존재할 수 있고, 따라서 단말은 전체 탐색공간에서 하나의 DCI 포맷에 대하여 총 14번의 블라인드 디코딩을 수행할 수 있음을 의미한다. 만약 해당 탐색공간에서 두 개의 DCI 포맷에 대한 탐색을 수행할 경우, 28번의 블라인드 디코딩이 수행될 수 있다.In [Table 1]

means the number of PRB pairs set for EPDCCH set p. Case 3 in [Table 1] may refer to a scenario determined by system parameters such as subframe structure, DCI format, and system bandwidth. Detailed information regarding this is unnecessary in explaining the present disclosure and will therefore be omitted. To explain [Table 1] as an example, if the EPDCCH set consists of 4 PRB pairs, there will be 6, 6, 2, and 2 EPDCCH candidates for aggregation levels 1, 2, 4, and 8, respectively. This means that the terminal can perform blind decoding a total of 14 times for one DCI format in the entire search space. If a search is performed for two DCI formats in the corresponding search space, blind decoding can be performed 28 times.

Figures 4 and 5 are diagrams illustrating the search space of EPDCCH of LTE, LTE-A, 5G or similar systems according to some embodiments of the present disclosure.

Figure 4 shows an example in which one EPDCCH set 401 consists of four PRB pairs 402. Note that there are four ECCEs (410) in one PRB pair (402), and for convenience in describing the present disclosure, they are expressed as a logical mapping method (306) for the ECCEs of FIG. 3 described above. . Figure 4 shows an example of the search space for aggregation level 1 (403), aggregation level 2 (404), and aggregation level 4 (405). According to the definition of the search space described above, one EPDCCH candidate 406 can be mapped to one ECCE 410 at aggregation level 1 (403), and one EPDCCH candidate 406 at aggregation level 2 (404). Can be mapped to two ECCEs (410), and at aggregation level 4 (405), one EPDCCH candidate (408) can be mapped to four ECCEs (410). In the example of FIG. 4, in the case of aggregation level 1 (403), there are 4 EPDCCH candidates 406, and in the case of aggregation level 2 (404), there are 4 EPDCCH candidates 407, and aggregation level 4 ( In the case of 403), there are two EPDCCH candidates 408.

According to an example of the EPDCCH search space shown in FIG. 4, one EPDCCH can be transmitted through one PRB pair for a specific aggregation level. Referring to FIG. 4, when EPDCCH is transmitted at aggregation level 1 (403), one of the search space corresponding to aggregation level 1 (403), that is, the EPDCCH candidate 406 set {ECCE0, ECCE4, ECCE8, ECCE12} EPDCCH may be transmitted by being mapped to a resource, and each EPDCCH candidate 406 may exist one in each of a total of four PRB pairs 402 constituting the EPDCCH set 401. As a result, one EPDCCH can be transmitted in one PRB pair. If EPDCCH is mapped and transmitted to ECCE0 at aggregation level 1 (403), it can be transmitted through PRB pair #0 (411), and if it is mapped and transmitted to ECCE8, it can be transmitted through PRB pair #02 (413). there is.

Figure 5 shows an example in which one EPDCCH set 501 consists of four PRB pairs (511, 512, 513, and 514). Note that there are four ECCEs 504 in one PRB pair, and for convenience in describing the present disclosure, they are expressed as a logical mapping method 306 for the ECCEs of FIG. 3 described above. Figure 5 shows an example of a search space for aggregation level 8 (502). According to the definition of the search space described above, at aggregation level 8 503, one EPDCCH candidate 503 can be mapped to 8 ECCEs (e.g., ECCE0, ECCE1, ECCE2, ECCE3, ECCE4 ECCE5, ECCE6, ECCE7). . In the example of FIG. 5, in the case of aggregation level 8 (503), there is one EPDCCH candidate (503) in the given EPDCC set (501). According to an example of the search space of the EPDCCH shown in FIG. 5, one EPDCCH uses two PRB pairs (e.g., PRB pair #0 (511) and PRB pair #1 (512) for a specific aggregation level 8 (502). ) can be transmitted through.

When performing EPDCCH RE mapping in FIG. 3, the UE and base station may not include REs that satisfy the following conditions in EREG allocation.

According to the above description, n _EPDCCH is the number of REs available for EPDCCH transmission within one PRB pair consisting of two adjacent slots. Among the REs within the PRB pair, CRS, NZP (non-zero power) CSI-RS, REs used as ZP (zero power) CSI-RS and EPDCCH DMRS are excluded.

Meanwhile, according to the explanation below, in the case of NZP CSI-RS, one of the {1, 1/2, 1/3} frequency densities can be set as upper layer signaling, and if the frequency density is not set or the frequency density is 1 It can be seen that CSI-RS is transmitted to every PRB. On the other hand, if the set CSI-RS frequency density is less than 1, the PRB subset through which CSI-RS is transmitted can be determined according to the comb offset value set by upper layer signaling. For example, when the frequency density is 1/2, when NZP-TransmissionComb is 0, CSI-RS can be transmitted in every even PRB, and when NZP-TransmissionComb is 1, CSI-RS can be transmitted in every odd PRB. You can. Additionally, when the frequency density is 1/3, CSI-RS can be transmitted in every first PRB when NZP-TransmissionComb is 0, and CSI-RS can be transmitted in every second PRB when NZP-TransmissionComb is 1. When NZP-TransmissionComb is 2, CSI-RS can be transmitted in every third PRB.

According to the above explanation, if the CSI-RS with the upper layer parameter NZP-FrequencyDensity set to 1/2 or 1/3 overlaps with an EPDCCH PRB pair and the EPDCCH bandwidth is more than 2 PRB, the base station and the terminal have different EPDCCH RE mapping for each PRB. There may be confusion regarding accurate EREG and ECCE allocation. To solve this problem, the present disclosure seeks to provide EPDCCH RE mapping methods considering the CSI-RS RE mapping pattern.

Hereinafter, embodiments of the present disclosure will be described in detail with reference to the attached drawings. At this time, it should be noted that in the attached drawings, identical components are indicated by identical symbols whenever possible. Additionally, detailed descriptions of well-known functions and configurations that may obscure the gist of the present disclosure will be omitted.

In addition, in describing embodiments of the present disclosure in detail, the main target will be LTE, LTE-A, or 5G systems, but the main gist of the present disclosure is also applicable to other communication systems with similar technical background and channel type. It can be applied with slight modifications without significantly departing from the scope of the disclosure, which may be possible at the discretion of a person skilled in the technical field of the disclosure.

<First embodiment>

The first embodiment provides the first method of EPDCCH RE mapping according to CSI-RS frequency density.

For example, the base station will not set an NZP-FrequencyDensity smaller than 1 within an EPDCCH PRB pair (or within a subframe where EPDCCH is transmitted) to prevent different CSI-RS RE patterns for each PRB depending on the CSI-RS frequency density setting. You can. The terminal may not expect “NZP CSI-RS with NZP-FrequencyDensity of 1/2 or 1/3” and EPDCCH PRB pair to be transmitted in the same PRB (or subframe).

According to the first embodiment, the base station can transmit a CSI-RS with an NZP-FrequencyDensity of 1/2 or 1/3 in a resource area without an EPDCCH PRB (i.e., a subframe in which EPDCCH is not transmitted), and the terminal can transmit a CSI-RS with an NZP-FrequencyDensity of 1/2 or 1/3. Mapping implementation blocks can be reused.

<Second Embodiment>

The second embodiment provides a second method of EPDCCH RE mapping according to CSI-RS frequency density. The second embodiment may be an embodiment that further expands the first embodiment.

For example, in order to prevent different CSI-RS RE patterns for each PRB according to the CSI-RS frequency density setting, the base station connects ZP CSI-RS REs for each PRB within an EPDCCH PRB pair (or within a subframe in which EPDCCH is transmitted). It may be possible to set NZP and ZP CSI-RS REs so that the union of NZP CSI-RS REs all have the same RE pattern. This is when “NZP CSI-RS with NZP-FrequencyDensity of 1/2 or 1/3” is set in the same PRB (or subframe) as the EPDCCH PRB pair and only some of the NZP-TransmissionComb values are used for CSI-RS transmission. This may mean that REs corresponding to the remaining NZP-TransmissionComb values should be set to ZP CSI-RS RE.

For example, when NZP-FrequencyDensity is 1/2, only NZP-TransmissionComb 0 is used for CSI-RS transmission, and REs corresponding to NZP-TransmissionComb 1 correspond to NZP-TransmissionComb 1 if they are not set to NZP CSI-RS RE. REs that do this must be set to the ZP CSI-RS RE pattern. Similar application is possible even when NZP-FrequencyDensity is 1/3, but detailed explanation is omitted.

As another example, when multiple CSI-RS configurations are aggregated to set up a {12, 16, 20, 24, 28, 32}-port non-precoded CSI-RS resource, each CSI-RS configuration has a different NZP. It may also be possible to satisfy the above condition using TransmissionComb values. For example, if a 16-port CSI-RS resource consisting of two 8-port CSI-RS configurations is set to NZP-FrequencyDensity 1/2, the first CSI-RS configuration uses NZP-TransmissionComb 0 and the second CSI-RS configuration may be able to maintain the same RE mapping pattern for each EPDCCH PRB pair using NZP-TransmissionComb 1. At this time, the terminal implementation can be further simplified by making the resourceConfig values indicated by each CSI-RS configuration the same (i.e., each CSI-RS configuration all specifies REs in the PRB at the same location). Here, the upper layer parameter resourceConfig refers to the row value referred to as CSI-RS config in [Table 2] below (one of 0 to 31), and the number of CSI-RS ports in each CSI-RS configuration (number of CSI reference signals configured ) in combination with one (k', l') pair, that is, the CSI-RS RE location within the PRB can be specified. In addition, it can be similarly applied to {12, 20, 24, 28, 32} port CSI-RS resources, but detailed description of all cases will be omitted.

As another example, it may be possible to use two or three beamformed CSI-RS resource pairs. For example, in the case of NZP-FrequencyDensity 1/2, different NZP-TransmissionComb values are assigned to two NZP CSI-RS pairs with the same resourceConfig value, or in the case of NZP-FrequencyDensity 1/3, three pairs with the same resourceConfig value are assigned. By assigning different NZP-TransmissionComb values to each NZP CSI-RS pair, the NZP CSI-RS REs at the same location in all PRBs within the EPDCCH band are identical to the case where the union of NZP CSI-RS REs is NZP-FrequencyDensity 1. It may be possible to enable it to be used.

According to the second embodiment, the base station can transmit a CSI-RS with NZP-FrequencyDensity of 1/2 or 1/3 regardless of the EPDCCH PRB, and the terminal can reuse the existing EPDCCH RE mapping implementation block.

[Table 2] CSI-RS RE mapping table

<Third Embodiment>

The third embodiment provides a third method of EPDCCH RE mapping according to CSI-RS frequency density.

For example, in order to prevent different CSI-RS RE patterns for each PRB according to the CSI-RS frequency density setting, the terminal sets the NZP-FrequencyDensity value within the EPDCCH PRB pair (or within the subframe in which the EPDCCH is transmitted) with the upper layer setting value. Regardless, it can always be assumed to be 1. In other words, if “NZP CSI-RS with NZP-FrequencyDensity of 1/2 or 1/3” and EPDCCH PRB pair are transmitted in the same PRB (or subframe), the UE performs CSI-RS measurement according to the corresponding settings, but EPDCCH RE Mapping (or EPDCCH rate matching) can be performed assuming NZP-FrequencyDensity 1.

According to the third embodiment, the base station can transmit a CSI-RS with NZP-FrequencyDensity of 1/2 or 1/3 regardless of the EPDCCH PRB, and the terminal can reuse the existing EPDCCH RE mapping implementation block.

<Fourth Embodiment>

The fourth embodiment is a modification of the third embodiment, and the base station and the terminal transmit within the EPDCCH PRB pair (or when the EPDCCH is transmitted) to prevent different CSI-RS RE patterns for each PRB according to the CSI-RS frequency density setting. You can promise that the NZP-FrequencyDensity value (within the subframe) will always be fixed to 1 regardless of the upper layer setting value. In other words, if “NZP CSI-RS with NZP-FrequencyDensity of 1/2 or 1/3” and EPDCCH PRB pair are not transmitted in the same PRB (or subframe), the UE transmits CSI by referring to the set NZP-FrequencyDensity and NZP-TransmissionComb values. -Perform RS measurement, but if “NZP CSI-RS with NZP-FrequencyDensity of 1/2 or 1/3” and EPDCCH PRB pair are transmitted in the same PRB (or subframe), CSI-RS assuming NZP-FrequencyDensity 1 Measurements can be performed. This may mean that EPDCCH RE mapping (or EPDCCH rate matching) in the base station and terminal is also always performed assuming NZP-FrequencyDensity 1.

According to the fourth embodiment, the base station can transmit a CSI-RS with NZP-FrequencyDensity of 1/2 or 1/3 regardless of the EPDCCH PRB, and the terminal can reuse the existing EPDCCH RE mapping implementation block.

<Embodiment 5>

The fifth embodiment provides a fifth method of EPDCCH RE mapping according to CSI-RS frequency density.

For example, in order to prevent different CSI-RS RE patterns for each PRB according to the CSI-RS frequency density setting, the UE sets the NZP-FrequencyDensity value less than 1 within the EPDCCH PRB pair (or within the subframe in which the EPDCCH is transmitted). EPDCCH RE mapping can be performed as is on the corresponding CSI-RS RE. That is, if “NZP CSI-RS with NZP-FrequencyDensity of 1” and EPDCCH PRB pair are transmitted in the same PRB (or subframe), the UE excludes the corresponding NZP CSI-RS RE from EPDCCH RE mapping, but “NZP CSI-RS with If NZP-FrequencyDensity of 1/2 or 1/3” and EPDCCH PRB pair are transmitted in the same PRB (or subframe), the corresponding NZP CSI-RS RE may not be excluded from EPDCCH RE mapping. The base station performs puncturing on the EPDCCH RE corresponding to the NZP CSI-RS RE of NZP-FrequencyDensity 1/2 or 1/3 in the EPDCCH PRB pair that is subsequently transmitted (i.e., the base station does not transmit the EPDCCH RE in the corresponding RE) and NZP Interference to CSI-RS can be managed.

According to the fifth embodiment, the base station can transmit a CSI-RS with NZP-FrequencyDensity of 1/2 or 1/3 regardless of the EPDCCH PRB, and the terminal can reuse the existing EPDCCH RE mapping implementation block.

In the description of the above-described embodiments, each embodiment has been described independently, but in actual application, it may be possible to operate in several combinations. For example, in the case of a CSI-RS resource set to NZP-FrequencyDensity 1/2, considering that the CSI-RS frequency density is relatively high and the impact of EPDCCH puncturing is large, the method of the third embodiment is followed, and NZP-FrequencyDensity 1/3 is used. In the case of a CSI-RS resource set to , it may be possible to follow the method of the fifth embodiment, considering that the CSI-RS frequency density is relatively low and the influence of EPDCCH puncturing can be ignored. In addition, various combinations may be possible.

In order to perform the above embodiments of the present invention, the processor, transceiver, and memory of the terminal are each shown in FIG. 6. The transmission and reception method of the terminal for performing the EPDCCH RE mapping method corresponding to the above-described first to fifth embodiments is shown, and in order to perform this, the processor, transceiver, and memory of the terminal must each operate according to the embodiment. do.

Figure 6 is a block diagram showing the structure of a terminal according to some embodiments of the present disclosure.

Referring to FIG. 6, the terminal of the present disclosure may include a processor 601, a transceiver 602, and a memory 603. However, the components of the terminal are not limited to the examples described above. For example, the terminal may include more or fewer components than the aforementioned components. In addition, the processor 601, the transceiver 602, and the memory 603 may be implemented in the form of a single chip. The processor 601 operates the terminal according to the above-described embodiment of the present disclosure. A series of processes can be controlled. For example, the processor 602 of the terminal can control downlink control channel reception and RS, data channel transmission and reception methods using OFDM signals according to embodiments of the present disclosure. The processor 601 may be composed of a plurality of processors, and the processor 601 executes a program stored in the memory 603 to generate a second signal in response to the first signal received from the base station through the transceiver 602. It can be controlled to determine the processing time required to transmit to the base station. Additionally, according to some embodiments, the EPDCCH RE mapping assumption of the UE may be controlled differently depending on the EPDCCH RE mapping method according to the embodiment of the present disclosure.

The transceiver unit 602 can transmit and receive signals to and from the base station. Signals that the terminal transmits and receives from the base station may include control information and data. According to some embodiments, the transceiver 602 may be comprised of an RF transmitter that up-converts and amplifies the frequency of a transmitted signal, and an RF receiver that amplifies the received signal with low noise and down-converts the frequency. Additionally, the transceiver 602 may receive a signal through a wireless channel and output it to the processor 601, and transmit the signal output from the processor 601 through a wireless channel.

The memory 603 can store programs and data necessary for operation of the terminal. Additionally, the memory 603 may store control information or data included in signals transmitted and received by the terminal. The memory 603 may be composed of a storage medium such as ROM, RAM, hard disk, CD-ROM, and DVD, or a combination of storage media. Additionally, the memory 603 may be composed of a plurality of memories. According to some embodiments, the memory 603 may store a program for transmitting and receiving a modulation signal, and may store a program for setting the group modulation method described above and transmitting and receiving the group modulation method.

Figure 7 is a block diagram showing the structure of a base station according to some embodiments of the present disclosure.

Referring to FIG. 7, the base station may include a processor 701, a transceiver 702, and a memory 703. According to the above-described communication method of the base station, the processor 701, transceiver 702, and memory 703 of the base station can operate. However, the components of the base station are not limited to the above examples. For example, a base station may include more or fewer components than those described above. In addition, the processor 701, the transceiver 702, and the memory 703 may be implemented in the form of a single chip.

The processor 701 can control a series of processes so that the base station can operate according to the embodiment of the present invention described above. For example, the processor 2401 of the base station can control downlink control channel allocation and transmission using OFDM signals, RS, and data channel resource mapping and transmission and reception methods according to embodiments of the present disclosure. The processor 1001 may be comprised of a plurality of processors, and the processor 1001 may control transmission of the first signal to the terminal by executing a program stored in the memory 1003. Additionally, according to some embodiments, the processor 701 may determine an EPDCCH RE mapping method according to conditions and control each component of the base station to transmit the EPDCCH accordingly.

The transceiver unit 702 can transmit and receive signals to and from the terminal. Signals transmitted and received from the terminal may include control information and data. According to some embodiments, the transceiver 702 may be composed of an RF transmitter that up-converts and amplifies the frequency of a transmitted signal, and an RF receiver that amplifies the received signal with low noise and down-converts the frequency. However, this is only an example of the transceiver 702, and the components of the transceiver 701 are not limited to the RF transmitter and RF receiver.

Additionally, the transceiver 702 may receive a signal through a wireless channel and output it to the processor 701, and transmit the signal output from the processor 701 through a wireless channel.

The memory 703 can store programs and data necessary for the operation of the base station. Additionally, the memory 703 may store control information or data included in signals obtained from the base station. The memory 703 may include a storage medium such as ROM, RAM, hard disk, CD-ROM, and DVD, or a memory consisting of a combination of storage media. Additionally, the memory 703 may be composed of a plurality of memories.

Methods according to embodiments described in the claims or specification of the present disclosure may be implemented in the form of hardware, software, or a combination of hardware and software.

When implemented as software, a computer-readable storage medium that stores one or more programs (software modules) may be provided. One or more programs stored in a computer-readable storage medium are configured to be executable by one or more processors in an electronic device (configured for execution). One or more programs include instructions that cause the electronic device to execute methods according to embodiments described in the claims or specification of the present disclosure.

These programs (software modules, software) include random access memory, non-volatile memory including flash memory, read only memory (ROM), and electrically erasable programmable ROM. (EEPROM: Electrically Erasable Programmable Read Only Memory), magnetic disc storage device, Compact Disc-ROM (CD-ROM: Compact Disc-ROM), Digital Versatile Discs (DVDs), or other types of It can be stored in an optical storage device or magnetic cassette. Alternatively, it may be stored in a memory consisting of a combination of some or all of these. Additionally, multiple configuration memories may be included.

In addition, the program can be accessed through a communication network such as the Internet, Intranet, LAN (Local Area Network), WLAN (Wide LAN), or SAN (Storage Area Network), or a combination of these. It may be stored in an attachable storage device that can be accessed. This storage device can be connected to a device performing an embodiment of the present disclosure through an external port. Additionally, a separate storage device on a communications network may be connected to the device performing embodiments of the present disclosure.

In the specific embodiments of the present disclosure described above, elements included in the present disclosure are expressed in singular or plural numbers depending on the specific embodiment presented. However, singular or plural expressions are selected to suit the presented situation for convenience of explanation, and the present disclosure is not limited to singular or plural components, and even components expressed in plural may be composed of singular or singular. Even expressed components may be composed of plural elements.

Meanwhile, the embodiments of the present disclosure disclosed in the specification and drawings are merely provided as specific examples to easily explain the technical content of the present disclosure and aid understanding of the present disclosure, and are not intended to limit the scope of the present disclosure. In addition, the specification and drawings disclose preferred embodiments of the present disclosure, and although specific terms are used, these are merely used in a general sense to easily explain the technical content of the present disclosure and aid understanding of the disclosure. It is not intended to limit the scope of the disclosure. That is, it is obvious to those skilled in the art that other modifications based on the technical idea of the present disclosure can be implemented. Additionally, each of the above embodiments can be operated in combination with each other as needed. For example, a base station and a terminal may be operated by combining parts of one embodiment of the present disclosure and another embodiment.

Claims (20)

In a method for a terminal to transmit and receive a signal,
Receiving Channel State Information Reference Signal (CSI-RS) resource configuration information and Enhanced Physical Downlink Control Channel (EPDCCH) resource configuration information from a base station;
At least one CSI-RS RE (Resource Element) identified based on the CSI-RS resource configuration information and at least one EPDCCH RE identified based on the EPDCCH resource configuration information are connected to the same PRB (Physical Resource Block) or the same sub identifying whether or not it is located in at least one of the frames;
When the at least one CSI-RS RE and the at least one EPDCCH RE are located in at least one of the same PRB or the same subframe, the frequency density of the at least one CSI-RS RE is 1/ identifying with a first value other than 2 or 1/3; and
Based on the first value, receiving the at least one CSI-RS RE.
The method of claim 1, wherein identifying the frequency density with the first value excluding the 1/2 or the 1/3 comprises:
A method of identifying the frequency density as 1.
The method of claim 1, wherein identifying the frequency density with the first value excluding the 1/2 or the 1/3 comprises:
Assuming the frequency density to be 1 or actually determining it to be 1.
According to clause 1,
When the CSI-RS RE and the EPDCCH RE are transmitted on the same PRB and the same subframe, puncturing is performed on the EPDCCH RE.
According to clause 1,
When the CSI-RS resource configuration information includes a plurality of CSI-RS settings, each of the plurality of CSI-RS settings has a different NZP-TransmissionComb value.
In a method for a base station to transmit and receive signals,
Transmitting Channel State Information Reference Signal (CSI-RS) resource configuration information and Enhanced Physical Downlink Control Channel (EPDCCH) resource configuration information to the terminal;
At least one CSI-RS RE (Resource Element) identified based on the CSI-RS resource configuration information and at least one EPDCCH RE identified based on the EPDCCH resource configuration information are connected to the same PRB (Physical Resource Block) or the same sub When located in at least one of the frames, setting the frequency density of the at least one CSI-RS RE to a first value excluding 1/2 or 1/3;
Based on the first value, transmitting the at least one CSI-RS RE.
The method of claim 6, wherein identifying the frequency density with the first value excluding the 1/2 or the 1/3 comprises:
A method of setting the frequency density to 1.
The method of claim 6, wherein identifying the frequency density with the first value excluding the 1/2 or the 1/3 comprises:
Assuming the frequency density to be 1 or actually determining it to be 1.
According to clause 6,
When the CSI-RS RE and the EPDCCH RE are transmitted on the same PRB and the same subframe, puncturing is performed on the EPDCCH RE.
According to clause 6,
When the CSI-RS resource configuration information includes a plurality of CSI-RS settings, each of the plurality of CSI-RS settings has a different NZP-TransmissionComb value.
In a terminal for transmitting and receiving signals,
Transmitter and receiver; and
At least one processor connected to the transceiver, wherein the at least one processor includes:
Receive CSI-RS (Channel State Information Reference Signal) resource setting information and EPDCCH (Enhanced Physical Downlink Control Channel) resource setting information from the base station,
At least one CSI-RS RE (Resource Element) identified based on the CSI-RS resource configuration information and at least one EPDCCH RE identified based on the EPDCCH resource configuration information are connected to the same PRB (Physical Resource Block) or the same sub Identify whether it is located in at least one of the frames,
When the at least one CSI-RS RE and the at least one EPDCCH RE are located in at least one of the same PRB or the same subframe, the frequency density of the at least one CSI-RS RE is 1/ Identifies by the first value excluding 2 or 1/3,
A terminal that receives the at least one CSI-RS RE based on the first value.
12. The method of claim 11, wherein the at least one processor:
A terminal that identifies the frequency density as 1.
12. The method of claim 11, wherein the at least one processor:
A terminal that assumes the frequency density to be 1 or actually determines it to be 1.
According to clause 11,
When the CSI-RS RE and the EPDCCH RE are transmitted on the same PRB and the same subframe, puncturing is performed on the EPDCCH RE.
According to clause 11,
When the CSI-RS resource configuration information includes a plurality of CSI-RS settings, each of the plurality of CSI-RS settings has a different NZP-TransmissionComb value.
In a base station for transmitting and receiving signals,
Transmitter and receiver; and
At least one processor connected to the transceiver, wherein the at least one processor includes:
Transmits CSI-RS (Channel State Information Reference Signal) resource setting information and EPDCCH (Enhanced Physical Downlink Control Channel) resource setting information to the terminal,
At least one CSI-RS RE (Resource Element) identified based on the CSI-RS resource configuration information and at least one EPDCCH RE identified based on the EPDCCH resource configuration information are connected to the same PRB (Physical Resource Block) or the same sub When located in at least one of the frames, set the frequency density of the at least one CSI-RS RE to a first value excluding 1/2 or 1/3,
Based on the first value, a base station transmits the at least one CSI-RS RE.
17. The method of claim 16, wherein the at least one processor:
A base station that sets the frequency density to 1.
17. The method of claim 16, wherein the at least one processor:
A base station that assumes the frequency density to be 1 or actually determines it to be 1.
According to clause 16,
When the CSI-RS RE and the EPDCCH RE are transmitted on the same PRB and the same subframe, puncturing is performed on the EPDCCH RE.
According to clause 16,
When the CSI-RS resource configuration information includes a plurality of CSI-RS settings, each of the plurality of CSI-RS settings has a different NZP-TransmissionComb value.