Method and apparatus for dynamically sharing frequency resources in a wireless communication system

Abstract

A method performed by a first base station includes: sending information indicating that a signal for channel measurement is to be sent to a second base station to a channel measurement target terminal, the channel measurement target terminal being determined from terminals that communicate with the first base station using a first frequency resource; sending information indicating that a signal for channel measurement is to be sent from the channel measurement target terminal to a second base station; receiving measurement information about a channel between the second base station and the channel measurement target terminal from the second base station; determining a shared frequency resource to be shared with the second base station from the first frequency resource based on the measurement information about the channel between the second base station and the channel measurement target terminal; and sending information about the shared frequency resource to the second base station.

Description

Technical Field

[0001] The present disclosure generally relates to a method and apparatus for dynamically sharing frequency resources in a wireless communication system. Background Art

[0002] Considering the development of mobile communication from generation to generation, technology mainly used for services for humans, such as voice calls, multimedia services and data services, has been developed. After the commercialization of the 5th generation (5G) communication system, it is expected that the number of devices connected to the communication network will grow exponentially. Examples of networked devices may include vehicles, robots, drones, household appliances, displays, smart sensors connected to various infrastructures, construction machinery and factory equipment. It is expected that mobile devices will evolve in various form factors, such as augmented reality glasses, virtual reality headsets and hologram devices. In order to provide various services by connecting hundreds of billions of devices and things in the 6th generation (6G) era, efforts have been made to develop improved 6G communication systems. For these reasons, 6G communication systems are called super 5G systems.

[0003] The 6G communication system, which is expected to be commercialized around 2030, will have a peak data rate of 1,000 gigabits per second (bps) and a radio latency of less than 100 microseconds (μsec), and will therefore be 50 times faster than the 5G communication system and have 1 / 10 of its radio latency.

[0004] In order to achieve such high data rates and ultra-low latency, it has been considered to implement 6G communication systems in the terahertz band (e.g., 95 GHz to 3 terahertz band). It is expected that since the path loss and atmospheric absorption in the terahertz band are more serious than in the millimeter wave (mmWave) band introduced in 5G, the technology that can ensure the signal transmission distance (coverage) will become more critical. It is necessary to develop multi-antenna transmission technology as the main technology to ensure coverage, including radio frequency (RF) elements, antennas, new waveforms with better coverage than orthogonal frequency division multiplexing (OFDM) schemes, beamforming and massive multiple input multiple output (MIMO) technology, full-dimensional MIMO (FD-MIMO) technology, array antennas and massive antennas. In addition, new technologies for improving the coverage of terahertz band signals have been discussed, such as metamaterial-based lenses and antennas, orbital angular momentum (OAM) technology, and reconfigurable smart surface (RIS) technology.

[0005] In addition, in order to improve spectrum efficiency and overall network performance, 6G communication systems have adopted technologies such as full-duplex technology for implementing uplink (UE transmission); downlink (Node B transmission) to simultaneously use the same frequency resources and network technology for utilizing satellites, high altitude platform stations (HAPS); an improved network structure for supporting mobile Node Bs for network operation optimization and automation; technology for using AI in wireless communications to improve overall network operations by considering AI from the initial stage of developing 6G technology and internalizing end-to-end AI support functions; and next-generation distributed computing technology for overcoming the limitations of UE computing capabilities through achievable ultra-high performance communications and computing resources on the network (multi-access edge computing (MEC) and cloud computing).

[0006] It is expected that such research and development of 6G communication systems will bring the next generation of hyper-connected experience to every corner of life. In particular, it is expected that services such as truly immersive extended reality (XR), high-fidelity mobile holograms, and digital replicas can be provided through 6G communication systems. Summary of the invention

[0007] Solution to the problem

[0008] According to one aspect of the present disclosure, a method for sharing frequency resources with a second base station performed by a first base station in a wireless communication system includes: sending information indicating that a signal for channel measurement is to be sent to a second base station to a channel measurement target terminal, the channel measurement target terminal being determined from terminals that communicate with the first base station using a first frequency resource; sending information indicating that a signal for channel measurement is to be sent from the channel measurement target terminal to the second base station; receiving measurement information about a channel between the second base station and the channel measurement target terminal from the second base station; determining a shared frequency resource to be shared with the second base station from the first frequency resource based on the measurement information about the channel between the second base station and the channel measurement target terminal; and sending information about the shared frequency resource to the second base station. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] The above and other aspects, features and advantages of certain embodiments of the present disclosure will become more apparent through the following description in conjunction with the accompanying drawings, in which:

[0010] Figure 1 is a diagram showing a basic structure of a time-frequency domain, i.e., a radio resource domain, in a wireless communication system according to an embodiment;

[0011] Figure 2 is a diagram illustrating a downlink control channel in a wireless communication system according to one embodiment;

[0012] Figure 3is a diagram illustrating transmission resources of a downlink control channel in a wireless communication system according to an embodiment;

[0013] Figure 4 is a diagram showing a configuration of a control resource set in a wireless communication system according to an embodiment;

[0014] Figure 5 is a diagram showing a configuration of a downlink resource block (RB) structure in a wireless communication system according to an embodiment;

[0015] Figure 6 is a diagram describing a method performed by a first base station of a first mobile network operator to share frequency resources with a second base station of a second mobile network operator according to one embodiment;

[0016] Figure 7 is a diagram showing a situation in which a first base station and a second base station communicate with a terminal using a shared frequency resource according to an embodiment;

[0017] Figure 8 is a flowchart of a method for sharing frequency resources with a second base station, performed by a first base station, according to an embodiment;

[0018] Fig. 9 is a flowchart of a method for sharing frequency resources with a first base station, performed by a second base station, according to an embodiment;

[0019] Fig.10 is a diagram showing a signal structure for channel measurement according to one embodiment;

[0020] Fig.11 is a sequential flow chart of a method of sending and receiving a signal for channel measurement according to one embodiment;

[0021] Fig.12 is a sequential flow chart of a method for sharing frequency resources according to one embodiment;

[0022] Fig.13 is a flowchart of a method for determining whether to stop sharing a shared frequency resource, performed by a first base station according to an embodiment;

[0023] Fig.14 is a flowchart of a method for determining whether to stop sharing a shared frequency resource, performed by a second base station, according to an embodiment;

[0024] Fig.15 is a sequential flow chart of a method for performing scheduling and data transmission and reception using a shared frequency according to one embodiment;

[0025] Fig.16is a sequential flow chart of a method for performing scheduling and data transmission and reception using a shared frequency according to one embodiment;

[0026] Fig.17 is a flowchart of a method for sharing frequency resources with a second base station, performed by a first base station, according to an embodiment;

[0027] Fig.18 is a flowchart of a method for sharing frequency resources with a second base station, performed by a first base station, according to an embodiment;

[0028] Fig.19 is a block diagram showing the structure of a first base station according to an embodiment; and

[0029] Fig. 20 is a block diagram showing the structure of a second base station according to an embodiment. DETAILED DESCRIPTION

[0030] According to one aspect of the present disclosure, a method for sharing frequency resources with a second base station in a wireless communication system performed by a first base station includes: sending information to a channel measurement target terminal determined from a terminal communicating with the first base station using a first frequency resource, the information indicating that a signal for channel measurement is to be sent to the second base station; sending information to the second base station, the information indicating that a signal for channel measurement is to be sent from the channel measurement target terminal; receiving measurement information about a channel between the second base station and the channel measurement target terminal from the second base station; determining a shared frequency resource to be shared with the second base station from the first frequency resource based on the measurement information about the channel between the second base station and the channel measurement target terminal; and sending information about the shared frequency resource to the second base station.

[0031] According to another aspect of the present disclosure, a method for sharing frequency resources with a first base station in a wireless communication system performed by a second base station includes: receiving information from the first base station, the information indicating that a signal for channel measurement will be sent from a channel measurement target terminal, and the channel measurement target terminal is determined from terminals that communicate with the first base station using first frequency resources; receiving a signal for channel measurement from the channel measurement target terminal; measuring a channel between the second base station and the channel measurement target terminal based on the signal for channel measurement and information indicating that a signal for channel measurement will be sent; sending measurement information about the channel between the second base station and the channel measurement target terminal to the first base station; and receiving information from the first base station about a shared frequency resource that the first base station will share with the second base station from the first frequency resource, wherein the shared frequency resource is determined based on the measurement information about the channel between the second base station and the channel measurement target terminal.

[0032] According to another aspect of the present disclosure, a first base station for sharing frequency resources with a second base station in a wireless communication system is provided. The first base station includes a communicator; a memory; and at least one processor, which is connected to the communicator and configured to: send information to a channel measurement target terminal determined from a terminal communicating with the first base station using a first frequency resource, the information indicating that a signal for channel measurement is to be sent to the second base station; send information to the second base station, the information indicating that a signal for channel measurement is to be sent from the channel measurement target terminal; receive measurement information about a channel between the second base station and the channel measurement target terminal from the second base station; determine a shared frequency resource to be shared with the second base station from the first frequency resource based on the measurement information about the channel between the second base station and the channel measurement target terminal; and send information about the shared frequency resource to the second base station.

[0033] A method and apparatus for dynamically sharing frequency resources in a wireless communication system are provided.

[0034] Various embodiments of the present disclosure are described with reference to the accompanying drawings. However, the various embodiments of the present disclosure are not limited to specific embodiments, and it should be understood that various modifications, equivalents and / or substitutions may be made to the embodiments described herein. With respect to the description of the accompanying drawings, similar parts may be marked with similar reference numerals.

[0035] Hereinafter, the operating principle of the present disclosure will be described in detail with reference to the accompanying drawings. When describing the present disclosure, when the detailed description of the relevant known function or configuration is determined to be unnecessary to obscure the details of the present disclosure, its detailed description may be omitted. The terms used herein are defined by considering the functions in the present disclosure, but these terms may change according to the intention of the user, a person of ordinary skill in the art, or a precedent. Therefore, it should be defined based on the content of the entire specification.

[0036] Throughout this disclosure, the expression “at least one of a, b, or c” indicates only a; only b; only c; both a and b; both a and c; both b and c; all of a, b, and c, or variations thereof.

[0037] Examples of the terminal may include a User Equipment (UE), a Mobile Station (MS), a cellular phone, a smart phone, a computer, or a multimedia system capable of performing a communication function.

[0038] In this disclosure, a controller may also be referred to as a processor.

[0039] Throughout the specification, a layer (or layer device) may also be referred to as an entity.

[0040] As used herein, for the convenience of description, terms used to identify access nodes, terms related to network entities, terms related to messages, terms related to interfaces between network entities, and terms related to various identification information are provided as examples. Therefore, the present disclosure is not limited to the terms used herein, and other terms referring to subjects with equivalent technical meanings can be used.

[0041] For ease of description, terms and names defined in the 3rd Generation Partnership Project Long Term Evolution (3GPP LTE) standard can be used. However, the present disclosure is not limited to these terms and names and can be equally applied to systems conforming to other standards. For ease of description, the term "eNB" used in the present disclosure can be used interchangeably with the term "gNB". That is, a base station described as an eNB can represent a gNB.

[0042] In general wireless communication systems, specific frequency resources are allocated specifically for specific services. Typically, in the case of cellular communications, the state leases specific frequency resources to specific mobile network operators, and the specific mobile network operators exclusively utilize the allocated specific frequency resources to maintain the cellular network. However, since the frequency resources allocated to each mobile network operator are not fully utilized except in time and space conditions with very high data traffic, these resources are wasted.

[0043] To improve this situation, a scenario where dynamic frequency sharing is implemented between mobile network operators can be considered. Frequency resources with priority use rights are allocated to each operator, but when the number of allocated frequency resources is small, other operators can be allowed to use these frequency resources. In the above scenario, operators do not need to be allocated unnecessary many frequencies in order to cope with the maximum traffic situation. Therefore, a system for dynamically sharing frequencies between mobile network operators will become a foundational technology for 6G or 5G that can efficiently operate increasingly scarce frequency resources.

[0044] A method will be described in which a base station of one mobile network operator dynamically shares or reuses frequencies with a base station of another mobile operator in the case of implementing dynamic frequency sharing between mobile network operators. For dynamic frequency sharing between base stations of different mobile network operators, the base station of the mobile network operator may need information about a terminal communicating with a base station of another mobile network operator and a terminal communicating with the mobile network operator itself. Therefore, a method will be described below in which a base station of a mobile network operator obtains channel information about a terminal communicating with a base station of another mobile network operator. In addition, a method will be described in which a terminal group capable of performing simultaneous transmission between base stations of a mobile network operator is formed by channel information obtained by a base station of a mobile network operator. In addition, a scheduling method of a base station in the case of dynamic frequency sharing will be described.

[0045] Figure 1 The diagram shows a basic structure of a time-frequency domain, namely, a radio resource domain, in a wireless communication system according to an embodiment.

[0046] exist Figure 1 In FIG. 1 , the horizontal axis represents the time domain and the vertical axis represents the frequency domain. The smallest transmission unit in the time domain is an OFDM symbol. 符号 OFDM symbols 101 may constitute a time slot 102, and two time slots may constitute a subframe 103. The length of the time slot 102 may be 0.5 milliseconds (ms), and the length of the subframe 103 may be 1.0 ms. A radio frame 104 is a time domain unit including 10 subframes. The minimum transmission unit in the frequency domain is a subcarrier. The entire system transmission bandwidth may include N sc BW Subcarriers 105. The basic unit of resources in the time-frequency domain is a resource element (RE) 106, which can be represented by an OFDM symbol index and a subcarrier index. A physical resource block (PRB) 107 can be represented by N subcarriers in the time domain. 符号 consecutive OFDM symbols 107 and N in the frequency domain SC RB Therefore, one RB 107 includes N consecutive subcarriers 108. 符号 xN sc RB RE 106. Generally speaking, the minimum transmission unit of data can be RB unit. In LTE system, N 符号 =7,N sc RB =12, and N sc BW and N sc RB It can be proportional to the system transmission bandwidth. However, these specific values ​​can be variably controlled depending on the system.

[0047] Next, downlink control information (DCI) in LTE and LTE-A systems will be described in detail.

[0048] Scheduling information for downlink data or uplink data in the LTE system can be sent from the base station to the terminal through DCI. DCI can define several formats. DCI formats defined according to whether the information is scheduling information for uplink data or scheduling information for downlink data, whether the DCI is a compact DCI with a small amount of control information, whether spatial multiplexing using multiple antennas is applied, and whether the DCI is a DCI for power control can be applied and operated. For example, DCI format 1, which is scheduling control information for downlink data, is configured to include at least the following control information:

[0049] - Resource allocation type 0 / 1 flag: Notifies whether the resource allocation scheme is type 0 or type 1. Type 0 allocates resources in units of RB groups (RBGs) by applying a bitmap scheme. In the LTE system, the basic unit of scheduling is an RB represented by time domain and frequency domain resources, and an RBG includes multiple RBs and becomes the basic unit of scheduling in the type 0 scheme. Type 1 allows allocation of specific RBs within an RBG.

[0050] - Resource Block Allocation: Notifies the RBs allocated for data transmission. Determines the resources represented according to the system bandwidth and resource allocation scheme.

[0051] - Modulation and Coding Scheme (MCS): Notifies the modulation scheme used for data transmission and the size of a transport block as data to be sent.

[0052] -Hybrid Automatic Repeat Request (HARQ) process number: notifies the HARQ process number.

[0053] - New data indicator: notifies whether HARQ transmission is HARQ initial transmission or HARQ retransmission.

[0054] - Redundancy version: Notifies the redundancy version of HARQ.

[0055] - Transmit Power Control (TPC) Command for Physical Uplink Control Channel (PUCCH): Notifies the transmit power control command for PUCCH.

[0056] The DCI may be transmitted through a Physical Downlink Control Channel (PDCCH) through a channel coding and modulation process.

[0057] A cyclic redundancy check (CRC) can be attached to the DCI message payload. The CRC can be scrambled by the radio network temporary identifier (RNTI) corresponding to the terminal identity. Different RNTIs are used according to the purpose of the DCI message (e.g., UE-specific data transmission, power control command, or random access response). That is, the RNTI is not sent explicitly, but is included in the CRC calculation process and then sent. When a DCI message sent via the PDCCH is received, the terminal can check the CRC by using the allocated RNTI. When the result of checking the CRC is correct, the terminal can know that the corresponding message has been sent to the terminal.

[0058] Figure 2 is a diagram illustrating a downlink control channel in a wireless communication system according to one embodiment.

[0059] refer to Figure 2 , showing the PDCCH 201 through which the DCI of LTE is transmitted. Figure 2, PDCCH 201 is time-multiplexed with PDSCH 202, which is a data transmission channel, and is sent through the entire system bandwidth. The area of ​​PDCCH 201 is represented by the number of OFDM symbols, and this can be indicated to the terminal as a control format indicator (CFI) sent through a physical control format indicator channel (PCFICH). By assigning PDCCH 201 to the OFDM symbol at the beginning of the subframe, the terminal can decode the downlink scheduling allocation as quickly as possible. This can reduce the decoding delay of the downlink shared channel (DL-SCH), that is, the overall downlink transmission delay. Since one PDCCH can carry a DCI message and can schedule multiple terminals for the downlink and uplink at the same time, multiple PDCCHs can be sent simultaneously in each cell. As a reference signal for decoding PDCCH 201, a cell-specific reference signal (CRS) 203 can be used. CRS 203 can be sent for each subframe over the entire frequency band, and scrambling and resource mapping can vary according to the cell identity (ID). Since CRS 203 is a reference signal shared by all terminals, UE-specific beamforming cannot be used. Therefore, the multi-antenna transmission scheme for PDCCH of LTE can be limited to open-loop transmission diversity. Of course, the present disclosure is not limited to the above examples. The number of CRS ports can be implicitly notified to the terminal from the decoding of the physical broadcast channel (PBCH).

[0060] Resource allocation of PDCCH 201 can be based on control channel elements (CCE). One CCE can be nine resource element groups (REGs) and can include a total of 36 REs. The number of CCEs required for a specific PDCCH 201 can be 1, 2, 4 or 8, which can depend on the channel coding rate of the DCI message payload. Therefore, different numbers of CCEs can be used to implement link adaptation of PDCCH 201. The terminal should detect the signal in a state where the terminal does not know the information about PDCCH 201. In LTE, a search space representing a group of CCEs is defined for blind decoding. The search space includes multiple sets of aggregation levels (AL) of each CCE, and this can not be explicitly signaled and can be implicitly defined by subframe numbers and functions through terminal identification. In each subframe, the terminal can decode PDCCH 201 for all possible resource candidates that can be created from the CCE in the configured search space, and can process the information that is valid for the corresponding terminal through CRC check.

[0061] The search space can be classified into a UE-specific search space and a common search space. A certain terminal group or all terminals can search the common search space of PDCCH 201 to receive cell common control information, such as a paging message or dynamic scheduling for system information. For example, scheduling allocation information (including cell operator information) of DL-SCH for transmission of system information block (SIB)-1 can be received by searching the common search space of PDCCH 201.

[0062] The entire PDCCH region in LTE includes a set of CCEs in a logical region, and there is a search space including a set of CCEs. The search space can be classified into a common search space and a UE-specific search space, and the search space for LTE PDCCH can be defined as follows:

[0063]

[0064]

[0065] According to the above definition of the search space for PDCCH, the UE-specific search space may not be explicitly signaled and may be implicitly defined by the subframe number and function through the terminal identification. In other words, because the UE-specific search space may change according to the subframe number. Therefore, the UE-specific search space may change over time. In this way, the problem (blocking problem) that a specific terminal among multiple terminals cannot use the search space due to other terminals can be solved. When all CCEs searched by the terminal have been used by other terminals scheduled in the same subframe and therefore the terminal is not scheduled in the corresponding subframe, this problem may not occur in the next subframe due to the change in the search space over time. For example, even when the UE-specific search spaces of terminal #1 and terminal #2 partially overlap each other in a specific subframe, it can be expected that the overlap in the next subframe will be different from the above overlap because the UE-specific search space will change for each subframe.

[0066] The common search space is defined as a set of pre-specified CCEs, because according to the definition of the search space of the PDCCH, a certain group of terminals or all terminals must receive the PDCCH. In other words, the common search space may not change according to the terminal identification or subframe number. Although there is a common search space for transmitting various system messages, the common search space can also be used to send control information for each terminal. In this way, the common search space can be used as a solution to the phenomenon that the terminal cannot be scheduled due to the lack of available resources in the UE-specific search space.

[0067] A search space is a set of candidate control channels, including CCEs that a terminal must try to decode at a given aggregation level. Since there are various aggregation levels that constitute a bundle from 1, 2, 4 or 8 CCEs, a terminal can have multiple search spaces. In LTE PDCCH, the number of PDCCH candidates to be monitored by a terminal in a search space defined according to the aggregation level is defined by the following Table 1.

[0068] Table 1

[0069]

[0070]

[0071] According to Table 1, the UE-specific search space can support aggregation levels {1, 2, 4, 8}, and in this case, the number of PDCCH candidates can be {6, 6, 2, 2}. The common search space can support aggregation levels {4, 8}, and in this case, the number of PDCCH candidates can be {4, 2}. The common search space only supports aggregation levels {4, 8} in order to improve coverage characteristics because system messages usually have to reach the cell edge.

[0072] The DCI sent to the common search space may be defined only for a specific DCI format, such as 0 / 1A / 3 / 3A / 1C, which corresponds to purposes such as power control for a terminal group or a system message. In the common search space, DCI formats with spatial multiplexing may not be supported. The present disclosure is not limited to the above examples. The downlink DCI format to be decoded in the UE-specific search space may vary according to the transmission mode configured for the corresponding terminal. Because the transmission mode is configured by radio resource control (RRC) signaling, there is no specified indication of the exact subframe number of whether the corresponding configuration is valid for the corresponding terminal. Therefore, the terminal can operate by always performing decoding of DCI format 1A regardless of the transmission mode so as not to lose communication.

[0073] The search space in LTE and LTE-A and the method of sending and receiving downlink control channels and downlink control information have been described above, and the downlink control channel in the 5G communication system currently under discussion will be described in more detail with reference to the accompanying drawings.

[0074] Figure 3 is a diagram illustrating transmission resources of a downlink control channel in a wireless communication system according to one embodiment.

[0075] refer to Figure 3, the basic unit REG of time and frequency resources constituting the control channel includes one OFDM symbol 301 in the time domain and 12 subcarriers 302 (i.e., one RB) in the frequency domain. In configuring the basic unit of the control channel, by assuming that the basic unit in the time domain is one OFDM symbol 301, the data channel and the control channel can be time-multiplexed within one subframe. By placing the control channel in front of the data channel, the processing time of the user can be reduced, and thus the delay time requirement can be easily met. By configuring the basic unit in the frequency domain of the control channel as one RB 302, frequency multiplexing between the control channel and the data channel can be performed more efficiently.

[0076] Can be cascaded Figure 3 The control channel regions with various sizes are configured by using the REG 303 shown. For example, when the basic unit for allocating a downlink control channel in 5G is a CCE 304, one CCE 304 may include a plurality of REGs 303. Figure 3 In the example shown, when REG 303 includes 12 REs and one CCE 303 includes 6 REGs 304, one CCE 303 may include 72 REs. When a downlink control resource set is configured, the downlink control resource set may include multiple CCEs 304. A specific downlink control channel may be transmitted after being mapped to one or more CCEs 304 according to an aggregation level AL in the control resource set. The CCEs 304 in the control resource set are distinguished by numbers. In this case, numbers may be assigned to the CCEs 304 according to a logical mapping scheme.

[0077] Figure 3 The basic unit of the downlink control channel shown (ie, REG 303) may include both the RE to which the DCI is mapped and the area to which the demodulation reference signal (DMRS) 305 (a reference signal used to decode the DCI) is mapped. Figure 3 As shown, DMRS 305 may be transmitted in three REs within one REG 303. For reference, since DMRS 305 is transmitted using the same precoding as the control signal mapped in REG 303, the terminal may decode the control information even without information about which precoding the base station applies.

[0078] Figure 4 is a diagram showing the configuration of a control resource set in a wireless communication system according to an embodiment.

[0079] Figure 4 An example is shown in which control resource set #1 401 and control resource set #2 402 are configured in a system bandwidth (410) on a frequency axis and a time slot (420) on a time axis (assuming that one time slot is Figure 4 7 OFDM symbols in the system). Control resource set #1 401 and control resource set #2 402 may be configured with a specific sub-band 403 within the entire system bandwidth 410 on the frequency axis. Control resource set #1 401 and control resource set #2 402 may be configured with one or more OFDM symbols in the time domain, and this may be defined as a control resource set duration 404. Figure 4 In the example shown, control resource set #1 401 is configured as a control resource set duration of two symbols, and control resource set #2 402 is configured as a control resource set duration of one symbol.

[0080] The base station can configure the control resource set of 5G for the terminal through higher layer signaling (e.g., system information, master information block (MIB) or RRC signaling). Configuring the control resource set for the terminal refers to providing information such as the location of the control resource set, subband, resource allocation of the control resource set, or duration of the control resource set. For example, multiple pieces of information shown in Table 2 below can be included in the provided information.

[0081] Table 2

[0082]

[0083] The present disclosure is not limited to the above examples. Figure 2 In addition to the configuration information, various information required to send a downlink control channel can be configured in the terminal.

[0084] Next, DCI in 5G will be described in detail.

[0085] In the 5G system, scheduling information about uplink data (or physical uplink shared channel (PUSCH)) or downlink data (or physical downlink data channel (PDSCH)) is sent from the base station to the terminal through DCI. The terminal can monitor the fallback DCI format and non-fallback DCI format about PUSCH or PDSCH. The fallback DCI format may include a fixed field between the base station and the terminal, and the non-fallback DCI format may include a configurable field.

[0086] The fallback DCI for scheduling PUSCH may include multiple pieces of information as shown in Table 3 below.

[0087] Table 3

[0088]

[0089]

[0090] The non-fallback DCI for scheduling PUSCH may include multiple pieces of information as shown in Table 4 below.

[0091] Table 4

[0092]

[0093]

[0094]

[0095] The fallback DCI for scheduling PDSCH may include multiple pieces of information as shown in Table 5 below.

[0096] Table 5

[0097]

[0098] The non-fallback DCI for scheduling PDSCH may include multiple pieces of information as shown in Table 6 below.

[0099] Table 6

[0100]

[0101]

[0102] DCI can be sent via PDCCH through a channel coding and modulation process. CRC can be attached to the DCI message payload. CRC can be scrambled by the RNTI corresponding to the terminal identifier. Different RNTIs are used according to the purpose of the DCI message (for example, UE-specific data transmission, power control command, or random access response). In addition, the RNTI is not sent explicitly, but is included in the CRC calculation process and then sent. When a DCI message sent via PDCCH is received, the terminal can use the allocated RNTI to check the CRC. When the result of checking the CRC is correct, the terminal can know that the corresponding message has been sent to the terminal.

[0103] The DCI that schedules PDSCH for system information (SI) may be scrambled by the SI-RNTI. The DCI that schedules PDSCH for a random access response (RAR) message may be scrambled by the RA-RNTI. The DCI that schedules PDSCH for a paging message may be scrambled by the P-RNTI. The DCI that notifies the slot format indicator (SFI) may be scrambled by the SFI-RNTI. The DCI that notifies the transmit power control (TPC) may be scrambled by the TPC-RNTI. The DCI that schedules UE-specific PDSCH or PUSCH may be scrambled by the cell RNTI (C-RNTI).

[0104] When a specific terminal is scheduled for a data channel (ie, PUSCH or PDSCH) through the PDCCH, data may be transmitted and received together with the DMRS in the scheduled resource region.

[0105] Figure 5 is a diagram showing a configuration of a downlink resource block (RB) structure in a wireless communication system according to one embodiment.

[0106] Figure 5 The example shown indicates a case where a specific terminal uses 14 OFDM symbols as one slot (or subframe) in downlink, transmits a PDCCH (501) in two initial OFDM symbols, and transmits a DMRS (502) in the third symbol. Figure 5 In the case of, in a specific RB in which the PDSCH is scheduled, the PDSCH (503) is transmitted while mapping data to REs, wherein DMRS is not transmitted in the third symbol and REs from the fourth symbol to the last symbol. Figure 5 The subcarrier spacing Δf represented in is 15 kilohertz (kHz) in the case of LTE / LTE-A system, and in the case of 5G system, one of {15, 30, 60, 120, 240, 480} kHz can be used.

[0107] Hereinafter, when there are a plurality of frequency resources and the use priority is configured differently for each frequency resource for different base stations, a method performed by a base station to obtain permission to use a certain frequency resource from another base station that is authorized to use a specific frequency resource with a higher priority and then uses the certain frequency resource will be described. More specifically, a method performed by different mobile network operators to share frequency resources held by each mobile network operator between base stations will be described.

[0108] Figure 6 is a diagram for describing a concept of a method performed by a first base station of a first mobile network operator to share frequency resources with a second base station of a second mobile network operator according to one embodiment.

[0109] refer to Figure 6 , the first mobile network operator can manage the first base station 10 and can provide services through the first frequency resources 610. In addition, the first base station 10 can use all or part of the first frequency resources 610 to communicate with the terminal.

[0110] The first terminal 630 may be a terminal subscribed to a communication service provided by a first mobile network operator, and the second terminal 640 may be a terminal subscribed to a communication service provided by a second mobile network operator. The first terminal 630 may receive a communication service from the first mobile network operator through the first base station 10, and the second terminal 640 may receive a communication service from the second mobile network operator through the second base station 20.

[0111] The first mobile network operator can provide communication services to the first terminal 630 by the first frequency resource 610 owned or managed by the first mobile network operator. However, even through the second frequency resource 620 not owned or managed by the first mobile network operator, the first mobile network operator can also provide communication services to the first terminal 630. For example, the first mobile network operator can communicate with the first terminal 630 through the first base station 10 using the second frequency resource 620 owned or managed by the second mobile network operator. Hereinafter, the terminal group (such as the first terminal 630) that communicates with the first base station 10 through the first frequency resource 610 will be referred to as the first terminal group. In addition, the terminal group (such as the second terminal 640) that communicates with the second base station 20 through the second frequency resource 620 will be referred to as the second terminal group.

[0112] When the first base station 10 communicates through the first frequency resource 610, the first base station 10 may be referred to as a primary base station (P-BS) relative to the first frequency resource 610. The first frequency resource 610 may be referred to as a primary carrier (P-carrier) relative to the first base station 10. In addition, when the first base station 10 communicates through the second frequency resource 620, the first base station 10 may be referred to as a secondary base station (S-BS) relative to the second frequency resource 620. The second frequency resource 620 may be referred to as a secondary carrier (S-carrier) relative to the first base station 10. Similarly, when a terminal communicates with a P-BS through a P-carrier, the terminal may be referred to as a primary user equipment (P-UE), and when a terminal communicates with an S-BS through an S-carrier, the terminal may be referred to as a secondary user equipment (S-UE).

[0113] In order for the second base station 20 to use the first frequency resource, the second base station 20 may have to negotiate with the first base station 10 to use the first frequency resource as an S carrier. During the negotiation process, the time and conditions for the availability of the S carrier may be negotiated. After the negotiation is completed, the second base station 20 may regard the first frequency resource as one of the frequency resources that the second base station 20 can use.

[0114] Figure 7 is a diagram illustrating a situation in which a first base station and a second base station communicate with a terminal using a shared frequency resource according to an embodiment.

[0115] refer to Figure 7 , the first base station 10 can communicate with the first terminal 630 using the first frequency resource 610. In addition, the second base station 20 can communicate with the second terminal 20 using the first frequency resource 610 shared by the first base station 10.

[0116] In this case, the signal sent by the second base station 20 to the second terminal 640 using the first frequency resource 610 may interfere with the signal sent and received between the first base station 10 and the first terminal 630. Similar to the first case 710, when the distance between the first terminal 630 and the second base station 20 is long, the interference strength may be weak, and the first base station 10 and the first terminal 630 can communicate normally using the first frequency resource 610. However, similar to the second case 720, when the distance between the first terminal 630 and the second base station 20 is short, the interference strength may be strong, and the first base station 10 and the first terminal 630 may not be able to communicate normally using the first frequency resource 610.

[0117] Therefore, in order to share the first frequency resource with the second base station 20, the first base station 10 needs to know measurement information about the channel state between the second base station 20 and the terminal communicating with the first base station 10 using the first frequency resource, and how to use the measurement information to determine which frequency resource to share.

[0118] Figure 8 is a flowchart of a method performed by a first base station and sharing frequency resources with a second base station according to an embodiment.

[0119] In step 810 , the first base station 10 transmits information instructing to transmit a signal for channel measurement to the second base station 20 , to a channel measurement target terminal determined from among terminals communicating with the first base station 10 using a first frequency resource.

[0120] In order to share the first frequency resource with the second base station 20, the first base station 10 may need to obtain measurement information about the channel between the second base station 20 and the terminal included in the first terminal group. To this end, the first base station 10 may determine at least one terminal to instruct the second base station 20 to send a signal for channel measurement. For example, the first base station 10 may determine a channel measurement target terminal from the terminals included in the first terminal group to instruct the sending of a signal for channel measurement.

[0121] The first base station 10 can determine at least one channel measurement target terminal from the terminals included in the first terminal group based on the position similarity to indicate the sending of a signal for channel measurement. In addition, the first base station 10 can determine a representative terminal from the determined channel measurement target terminals, and can send information only to the representative terminal to indicate the transmission of a signal for channel measurement. In addition or alternatively, the first base station 10 can determine at least one channel measurement target terminal based on the channel determined to be measured for sharing the first frequency resource to indicate the sending of a signal for channel measurement to the second base station 20. In the following, for ease of explanation, the terminal determined to indicate the sending of a signal for channel measurement from the terminals included in the first terminal group is referred to as a channel measurement target terminal.

[0122] The information indicating that a signal for channel measurement is transmitted may include information about resources for transmitting the signal for channel measurement. The information about resources for transmitting the signal for channel measurement may be different for each channel measurement target terminal. For example, resources such as different time, frequency, and spatial streams may be allocated to each terminal in order to transmit the signal for channel measurement.

[0123] The resources used to send the signal for channel measurement may include symbols of a certain duration or longer, and the information about the resources of the signal for channel measurement may include information about symbols of a certain duration or longer. The channel measurement target terminal may not know the physical distance to the second base station 20, and the signal for channel measurement may be sent without considering the physical distance. Therefore, the timing at which the second base station 20 receives the transmitted signal for channel measurement may be inconsistent with each other. Generally, the signal sent by the terminal may include multiple orthogonal frequency division multiplexing access (OFDMA) symbols in a subframe as the minimum transmission unit. When a general OFDMA symbol with a short symbol time length is used to send a signal for channel measurement, in the case of synchronization mismatch, the timing at which the signal arrives at the second base station 20 is inconsistent with each other, and therefore, the second base station 20 may not receive the signal for channel measurement.

[0124] Fig.10 is a diagram showing a signal structure for channel measurement according to one embodiment.

[0125] In order to send a signal for channel measurement, such as Fig.10 As shown, it may be necessary to use symbols 1020 whose symbol time length 1025 is a certain time length or longer (i.e., a certain size or smaller subcarrier spacing) instead of symbols (such as general symbols 1010) with a short symbol time length 1015. These symbols can be similar to random access channel (RACH) symbols that can be used when uplink synchronization is not matched in LTE or NR.

[0126] The information indicating the transmission of the signal for channel measurement may include information about the sequence to be used to transmit the signal for channel measurement. The channel measurement target terminal may simultaneously transmit the signal for channel measurement to the second base station 20 through the same resource. Therefore, the first base station 10 may instruct the channel measurement target terminal to transmit the signal for channel measurement based on the sequence so as to distinguish between the terminals.

[0127] The sequence used to transmit the signal for channel measurement may be a Zadoff-Chu sequence. Alternatively, the sequence used to transmit the signal for channel measurement may be a maximum length sequence (MLS) (or m-sequence).

[0128] In step 820 , the first base station 10 may transmit, to the second base station 20 , information indicating that a signal for channel measurement is to be transmitted from the channel measurement target terminal.

[0129] When the first base station 10 sends information indicating that a signal for channel measurement will be sent to the second base station 20 from at least one terminal (i.e., a channel measurement target terminal) (determined from the terminals included in the first terminal group), it may mean that the first base station 10 instructs the second base station 20 to receive the signal for channel measurement, and obtains measurement information about the channel between the second base station 20 and the channel measurement target terminal based on the received signal, and sends the measurement information to the first base station 10.

[0130] The information indicating that a signal for channel measurement is to be sent may include information about resources for sending signals for channel measurement. For example, the information about resources for sending signals for channel measurement may include information about resources such as time, frequency and / or spatial streams for sending signals for channel measurement for each terminal. The information about resources for sending signals for channel measurement can be used to receive signals for channel measurement and can also be used to identify a channel measurement target terminal. In addition, the information about resources for sending signals for channel measurement can be used to perform channel measurement.

[0131] The information indicating that a signal for channel measurement is to be transmitted may include information about a time when the second base station 20 performs monitoring in order to receive a signal for channel measurement. The second base station 20 may be in a state where synchronization information of the first base station 10 has not yet been obtained. The first base station 10 may transmit information about how much time (Δt) it takes from a point in time when the first base station 10 transmits information indicating that a signal for channel measurement is to be transmitted until the signal for channel measurement arrives at the first base station 10. The second base station 20 may perform monitoring in order to receive a signal for channel measurement within a time interval determined based on the information about Δt received from the first base station 20 and a point in time when the first base station 10 transmits information indicating that a measurement signal for a channel is to be transmitted.

[0132] In addition, the information indicating that a signal for channel measurement is to be transmitted may include information about a time (t=t1) at which the channel measurement target terminal transmits a signal for channel measurement to the second base station 20. The second base station 20 may be synchronized with the first base station 10 based on the information about the time (t=t1) at which the signal for channel measurement is transmitted.

[0133] Fig.11 is a sequential flow chart of a method of transmitting and receiving a signal for channel measurement according to one embodiment.

[0134] refer to Fig.11 In step 1112, the first base station 10 instructs the first channel measurement target terminal 1101 to send a signal for channel measurement at t=t1 using a sequence (sequence 1), and in step 1114 instructs the first channel measurement target terminal 1101 to send a signal for channel measurement at t=t1 using a sequence (sequence 2). In addition, in step 1120, while sending information indicating that a signal for channel measurement is to be sent to the second base station 20, the first base station 10 may send information about the time when monitoring will be performed in order to receive a signal for channel measurement (for example, including information indicating that the signal for channel measurement will arrive after Δt from the time point when the signal for channel measurement has been sent). Based on the information received from the first base station 10, the second base station 20 receives the signal for channel measurement in step 1130 and may be synchronized with the first base station 10.

[0135] The information indicating that a signal for channel measurement is to be transmitted may include information about a sequence for transmitting the signal for channel measurement. The information about the sequence may be used as information for identifying a channel measurement target terminal.

[0136] The information indicating that a signal for channel measurement is to be sent may include information about the maximum permissible interference level (or strength) of the signal sent by the second base station 20 to the signal between the first base station 10 and the channel measurement target terminal. In order to communicate with the terminals included in the first terminal group, the first base station 10 may determine the total permissible interference level of the signals sent and received by the terminals included in the first terminal group. Specifically, the first base station 10 may determine the maximum permissible interference level from the determined total permissible interference levels by the second base station 20 that shares or is scheduled to share a frequency. The first base station 10 may send information about the maximum permissible interference level caused by the second base station 20 to the second base station 20. The maximum permissible interference level caused by the signal sent by the second base station 20 may become a reference for determining the maximum power of the signal sent by the second base station 20 using the shared frequency shared by the first base station 10.

[0137] The information indicating that a signal for channel measurement is to be transmitted may include information used by the second base station 20 to measure a channel between the second base station 20 and the channel measurement target terminal. For example, the information used to perform channel measurement may include information about a propagation model for channel measurement, information about the location of the channel measurement target terminal, and information about a difference between a frequency band in which a signal for channel measurement is to be transmitted and a candidate shared frequency band (e.g., a difference in channel characteristics due to a difference in frequency interval and frequency band).

[0138] The first base station 10 may add at least one of information about resources for transmitting a signal for channel measurement, information about a time for performing monitoring in order to receive a signal for channel measurement, information about a sequence for transmitting a signal for channel measurement, and information for measuring a channel between the second base station 20 and a channel measurement target terminal, or any combination thereof, to the information indicating that a signal for channel measurement is to be transmitted. The first base station 10 may transmit all the information to the second base station 20 at once, or may transmit the information separately as separate pieces of information to the second base station 20.

[0139] Reference again Figure 8 In step 830, the first base station 10 receives measurement information about a channel between the second base station 20 and the channel measurement target terminal from the second base station 20.

[0140] The measurement information about the channel between the second base station 20 and the channel measurement target terminal may be a response (or feedback) to the information indicating that a signal for channel measurement is to be transmitted. The measurement information about the channel between the second base station 20 and the channel measurement target terminal may be information measured by the second base station 20 based on the signal for channel measurement received from the channel measurement target terminal. In step 820, in order to perform channel measurement, the second base station 20 can use the information received from the first base station 10.

[0141] The measurement information about the channel may include a measurement result (e.g., reception strength) of a signal for channel measurement received from the channel measurement target terminal. In addition, the measurement information about the channel may include information about the maximum transmission power (P_max (UE_ID)) that the second base station 20 can use to transmit a signal through each channel between the second base station 20 and the channel measurement target terminal. When the second base station 20 uses the same frequency resources as those used by the first base station 10 and the channel measurement target terminal to transmit a signal, the maximum transmission power may refer to the maximum transmission power that the second base station 20 can use within a range not exceeding the maximum allowable interference level of the signal between the first base station 10 and the channel measurement target terminal. In addition, in step 820, the information about the maximum transmission power may be measured by the second base station 20 based on the information about the maximum allowable interference level (or strength) sent by the first base station 10. The information about the maximum transmission power may be measured for each channel measurement target terminal (i.e., for each channel), and may include information about the terminal corresponding to each channel.

[0142] Steps 810 to 830 may be performed to determine whether there is a situation suitable for the first base station 10 to share the first frequency resource with the second base station 20. Steps 810 to 830 may be performed temporarily or periodically and may be performed under specific conditions. For example, when the second base station 20 requests the first base station 10 to share the first frequency resource, the first base station 10 may perform steps 810 to 830 to determine whether to share the first frequency resource with the second base station 20.

[0143] Steps 810 to 830 may be replaced by the following operations. By using methods such as a propagation model or location-based channel measurement, the first base station 10 is able to use the location information of the second base station 20 and the location information of the channel measurement target terminal to determine the maximum transmission power that the second base station 20 can use so as to send a signal through each channel between the second base station 20 and the channel measurement target terminal, and may send information about the determined maximum transmission power to the second base station 20. Alternatively, the first base station 10 may provide the location information about at least one terminal included in the first terminal group to the second base station 20, and may enable the second base station 20 to determine the above-mentioned maximum transmission power based on the location information about the at least one terminal.

[0144] In step 840 , the first base station 10 determines a shared frequency resource to be shared with the second base station 20 from among the first frequency resources based on measurement information on a channel between the second base station 20 and the channel measurement target terminal.

[0145] The first base station 10 may determine to share all or part of the first frequency resources with the second base station 20. That is, the first base station 10 may determine the frequency band to be shared with the second base station 20 from the frequency band of the first frequency resources. For example, the first base station 10 may determine to share all or part of the first frequency resources based on the measurement information received from the second base station 20 about the channel between the second base station 20 and the channel measurement target terminal. Hereinafter, sharing frequency resources may refer to all or part of the first frequency resources that the first base station 10 determines to share with the second base station.

[0146] The first base station 10 may determine at least one terminal from the terminals included in the first terminal group that will communicate with the first base station 10 using the determined shared frequency resources. Hereinafter, a terminal group including at least one terminal communicating with the first base station 10 using shared frequency resources is referred to as a frequency sharing terminal group.

[0147] The first base station 10 may determine a frequency sharing terminal group including a terminal to be communicated with the first base station 10 using a shared frequency resource from a terminal communicating with the first base station 10 using a first frequency resource. For example, the first base station 10 may determine the frequency sharing terminal group based on information about the position of the terminal included in the first terminal group. The first base station 10 may determine a terminal group whose positions are adjacent to each other among the terminals included in the first terminal group as a frequency sharing terminal group. In addition, in step 830, the first base station 10 may determine the frequency sharing terminal group based on measurement information about a channel received from the second base station 20. The first base station 10 may determine a terminal group corresponding to a signal having similar strength received by the second base station 20 from a signal for channel measurement as a frequency sharing terminal group. In addition, the first base station 10 may determine a terminal group having a similar generated traffic pattern as a frequency sharing terminal group.

[0148] The first base station 10 may perform resource allocation (or scheduling) only within the shared frequency resources for the terminals included in the determined frequency sharing terminal group. In addition, the first base station 10 may not allocate resources to other terminals within the shared frequency resources.

[0149] The first base station 10 may allocate identifiers to the terminals included in the frequency sharing terminal group. The first base station 10 may allocate public identifiers to the terminals included in the frequency sharing terminal group. The first base station 10 may perform signaling on the terminals included in the frequency sharing terminal group based on the public identifier. The first base station 10 may allocate resources to the frequency sharing terminal based on the public identifier, or may notify a sequence to be used when transmitting a signal.

[0150] Based on the determined frequency sharing terminal group, the first base station 10 can determine the maximum transmission power that the second base station 20 can use in order to use the shared frequency resources to send signals. For example, based on the information about the maximum transmission power (P_max (UE_ID)) received in step S830, which can be used by the second base station 20 to send signals through each channel between the second base station 20 and the channel measurement target terminal, the first base station 10 can determine the maximum transmission power that the second base station 20 can use in order to use the shared frequency resources corresponding to each terminal included in the first terminal group to send signals. The first base station 10 can determine the minimum value from the maximum transmission power value corresponding to each terminal included in the frequency sharing terminal group as the maximum transmission power that can be used to send signals using the shared frequency corresponding to the frequency sharing terminal group. This is done to prevent interference at a level exceeding the interference tolerance from occurring in all terminals included in the frequency sharing terminal group.

[0151] The first base station 10 may determine a period for sharing the shared frequency resources or a condition for stopping sharing the shared frequency resources. When the determined period has passed or the condition for stopping sharing the shared frequency resources is met, the sharing of the shared frequency resources between the first base station 10 and the second base station 20 may be stopped.

[0152] In step 850, based on the measurement information about the channel, the first base station 10 transmits to the second base station 20 information about the shared frequency resources to be shared with the second base station 20 in the first frequency resources.

[0153] When the first base station 10 transmits information about the determined shared frequency resources to the second base station 20, the second base station 20 may be allowed to share the frequency resources.

[0154] The information about the shared frequency resources sent from the first base station 10 to the second base station 20 may include information about the frequency band of the shared frequency resources and information about the frequency sharing terminal group. The first base station 10 may determine the terminals that use the shared frequency resources for communication in groups (such as frequency sharing terminal groups, not single terminal units), and operate the shared frequency resources so that the overhead of the signaling to be sent and received by the first base station 10 can be reduced (for example, when the frequency resources are operated in terminals, signaling for each terminal is required), and user information about each terminal can be hidden. The present disclosure provides an embodiment of operating the terminals that are to use the shared frequency resources for communication in groups (such as frequency sharing terminal groups), but may also include an embodiment of operating the terminals that are to use the shared frequency resources for communication in units of individual terminals.

[0155] In addition, the information about the shared frequency resources may include information about the maximum transmission power that the second base station 20 can use to transmit signals using the shared frequency resources. In addition, the information about the shared frequency resources may include a period of sharing the shared frequency resources or a condition for stopping sharing the shared frequency resources.

[0156] Fig. 9 FIG. 1 is a flowchart of a method for sharing frequency resources with the first base station 10 and executed by the second base station 20 according to an embodiment. Fig. 9 In the description, briefly describe Figure 8 Description of duplicate content.

[0157] In step 910, the second base station 20 receives information from the first base station 10 indicating that a signal for channel measurement is to be sent from a channel measurement target terminal, which is determined from terminals that communicate with the first base station 10 using the first frequency resource (i.e., terminals included in the first terminal group). Step 910 may correspond to Figure 8 Step 820.

[0158] The information indicating that a signal for channel measurement is to be transmitted may include at least one of information about a resource for transmitting a signal for channel measurement or information about a sequence to be used for transmitting a signal for channel measurement. The information about a resource for transmitting a signal for channel measurement may include information indicating that the signal for channel measurement includes symbols of a certain duration or longer, and information indicating that the sequence to be used for transmitting a signal for channel measurement is a Zadoff-Chew sequence.

[0159] The information indicating that a signal for channel measurement is to be transmitted may include information on a time when the second base station 20 performs monitoring in order to receive the signal for channel measurement.

[0160] The information indicating that a signal for channel measurement is to be transmitted may include information on a maximum allowable interference level (or strength) of a signal transmitted by the second base station 20 with respect to a signal between the first base station 10 and the channel measurement target terminal.

[0161] In step 920, the second base station 20 receives a signal for channel measurement from the channel measurement target terminal.

[0162] The second base station 20 can monitor the signal based on information about the resources for sending the signal for channel measurement and information about the time when monitoring will be performed in order to receive the signal for channel measurement. For example, the second base station 20 can compare the signal received at the time (or time interval window) for performing monitoring notified by the first base station 10 with the information about the resources for sending the signal for channel measurement. In this way, the second base station 20 can obtain the signal for channel measurement from the monitored signal. In addition, the second base station 20 can be synchronized with the first base station 10 based on the information about the time for performing monitoring and the received signal for channel measurement.

[0163] Reference again Fig.11 , the second base station 20 may monitor the signal based on the information about the time when the monitoring will be performed so as to receive the signal for channel measurement, which is notified by the second base station 20 (for example, may include information indicating that the signal for channel measurement will arrive after Δt from the time point when the signal for channel measurement is transmitted). The second base station 20 obtains the signal for channel measurement through the monitoring in step 1130, which is transmitted by the first channel measurement target terminals 1101 and 1102. In addition, based on the information received from the first base station 10, the second base station 20 may receive the signal for channel measurement and may be synchronized with the first base station 10.

[0164] In step 930 , the second base station 20 may measure a channel between the second base station 20 and the channel measurement target terminal based on the information indicating that a signal for channel measurement is to be transmitted and the signal for channel measurement.

[0165] The second base station 20 may measure the received signal strength of the signal for channel measurement received from the channel measurement target terminal. In addition, the second base station 20 may determine the maximum transmission power (P_max (UE_ID)) that the second base station 20 can use to send a signal through each channel based on the information received from the first base station 10 about the maximum allowed interference level of the signal between the first base station 10 and the channel measurement target terminal. The second base station 20 may measure the channel for each channel measurement target terminal.

[0166] In step 940, the second base station 20 sends measurement information about the channel between the second base station 20 and the channel measurement target terminal to the first base station 10. Step 940 may correspond to Figure 8 Step 830.

[0167] The second base station 20 may send measurement information about the channel between the second base station 20 and the channel measurement target terminal to the first base station 10 as a response (or feedback) to the information indicating that a signal for channel measurement sent by the first base station 10 is to be sent. The measurement information about the channel may include a measurement result (e.g., received signal strength) of the signal for channel measurement received from the channel measurement target terminal. Specifically, the measurement information about the channel may include information about the maximum transmission power (P_max (UE_ID)) that the second base station 20 can use to send a signal through each channel between the second base station 20 and the channel measurement target terminal.

[0168] Steps 910 to 940 may be performed to determine whether it is a case where the first base station 10 shares the first frequency resource with the second base station 20. Steps 910 to 940 may be performed temporarily or periodically and may be performed under specific conditions. For example, steps 910 to 940 may be performed after the second base station 20 requests the first base station 10 to share the first frequency resource.

[0169] In step 950, the second base station 20 receives information about a shared frequency resource in the first frequency resource that the first base station 10 will share with the second base station 20 from the first base station 10. Step 950 may correspond to Figure 8 Step 850.

[0170] Receiving the information about the determined shared frequency resources from the first base station 10 by the second base station 20 may mean that the second base station 20 obtains permission for the shared frequency resources from the first base station 10 .

[0171] The information about the shared frequency resources may include at least one of information about the frequency band of the shared frequency resources, information about the frequency sharing terminal group, or information about the maximum transmission power that the second base station 20 can use to send a signal using the shared frequency resources. In addition, the information about the shared frequency resources may include a period for sharing the shared frequency resources or a condition for stopping sharing the shared frequency resources.

[0172] The frequency sharing terminal group may include terminals that will communicate with the first base station 10 using shared frequency resources from among terminals that communicate with the first base station 10 using the first frequency resources. The frequency sharing terminal group may be determined by the first base station 10 based on at least one of measurement information about a channel or information about the location of the terminal that communicates with the first base station 10 using the first frequency resources. In addition, the maximum transmission power that the second base station 20 can use in order to transmit a signal using the shared frequency resources may be determined by the first base station 10 based on the frequency sharing terminal group.

[0173] The second base station 20 can use the shared frequency resources to communicate with at least one terminal included in the second terminal group. For example, the second base station 20 can determine the terminal to be scheduled for the shared frequency resources from the second terminal group based on the information about the shared frequency resources. Based on the information about the maximum transmission power that the second base station 20 can use to send a signal using the shared frequency resources, the second base station 20 can determine the terminal to be scheduled for the shared frequency resources and the transmission power to be used to send a signal through the shared frequency resources from the second terminal group. For example, even when the second base station 20 sends a signal with the maximum transmission power that the second base station 20 can use, the terminal that does not receive the signal can be excluded from the terminal for scheduling the shared frequency resources.

[0174] The second base station 20 can schedule the shared frequency resources to the terminal based on the information about the frequency band of the shared frequency resources. In addition, the second base station 20 can schedule the shared frequency resources based on the period for sharing the shared frequency resources and the condition for stopping sharing the shared frequency resources configured by the first base station 10.

[0175] According to the above-described embodiments of the present disclosure, the first base station 10 can share all or part of the first frequency resource in the case where the second base station 20 is within a range in which interference with the terminals included in the first terminal group does not occur. In addition, the first base station 10 pre-provides information about a frequency sharing terminal group that communicates with the second base station 20 using shared frequency resources, while sharing the frequency resources with the second base station 20, so that the second base station 20 can freely schedule the shared frequency resources based on the information about the frequency sharing terminal group.

[0176] Fig.12is a sequential flow chart of a method for sharing frequency resources according to an embodiment. Fig.12 In the description, briefly describe Figure 8 and Fig. 9 Description of duplicate content.

[0177] In step 1210 , the first base station 10 sends information to the channel measurement target terminal 12 instructing the second base station 20 to send a signal for channel measurement.

[0178] In step 1220 , the first base station 10 transmits information indicating that a signal for channel measurement is to be transmitted from the channel measurement target terminal to the second base station 20 .

[0179] In step 1230, the channel measurement target terminal 12 transmits a signal for channel measurement to the second base station 20. The second base station 20 may receive the signal for channel measurement transmitted by the channel measurement target terminal 12 based on the information indicating that the signal for channel measurement is to be transmitted.

[0180] In step 1240 , the second base station 20 measures a channel between the second base station 20 and the channel measurement target terminal 12 .

[0181] In step 1250 , the second base station 20 sends measurement information about a channel between the second base station 20 and the channel measurement target terminal to the first base station 10 .

[0182] In step 1260, the first base station 10 determines, from the first frequency resources, a shared frequency resource to be shared with the second base station 20. The shared frequency resource may be determined based on measurement information about a channel.

[0183] In step 1270 , the first base station 10 sends information about shared frequency resources to the second base station 20 .

[0184] Fig.13 is a flowchart of a method for determining whether to stop sharing the shared frequency resources executed by the first base station 10 according to an embodiment. The first base station 10 may Figure 8 Execute after the steps Fig.13 steps.

[0185] In step 1310 , the first base station 10 sends information instructing the terminals included in the frequency sharing terminal group to send a signal for channel measurement to the second base station 20 .

[0186] In order to determine whether to continue to share the first frequency resource with the second base station 20, the first base station 10 needs to monitor the state change of the channel between the second base station 20 and the terminal included in the frequency sharing terminal group, and needs to obtain measurement information about the channel. To this end, the first base station 10 can send information indicating that a signal for channel measurement is periodically (or temporarily) sent to the second base station 20 to the terminal (or representative UE) included in the frequency sharing terminal group.

[0187] According to one embodiment, the information indicating that a signal for channel measurement is to be transmitted may include information on resources used to transmit the signal for channel measurement, information on a sequence to be used to transmit the signal for channel measurement, and the like.

[0188] In step 1320 , the first base station 10 receives, from the second base station 20 , measurement information on channels between the second base station 20 and the terminals included in the frequency sharing terminal group.

[0189] The measurement information about the channel between the second base station 20 and the terminal included in the frequency sharing terminal group may include a measurement result (e.g., reception strength) of a signal for channel measurement received from the channel measurement target terminal. In addition, based on the information about the maximum allowable interference level to the signal between the first base station 10 and the terminal included in the frequency sharing terminal group, the measurement information about the channel may include information about the maximum transmission power that the second base station 20 can use to send a signal through each channel between the second base station 20 and the terminal included in the frequency sharing terminal group.

[0190] In step 1330 , the first base station 10 determines whether to stop sharing the shared frequency resources with the second base station 20 based on measurement information on channels between the second base station 20 and the terminals included in the frequency sharing terminal group.

[0191] Based on the measurement information about the channel between the second base station 20 and the terminal included in the frequency sharing terminal group, the first base station 10 can measure the interference level of the frequency sharing terminal group by using the signal transmission of the second base station 20 of the shared frequency. The first base station 10 can compare the measured interference level with the maximum allowable interference level (or strength) of the signal between the first base station 10 and the channel measurement target terminal. When the measured interference level exceeds the maximum allowable interference level, the first base station 10 can determine to stop sharing the shared frequency resource with the second base station 20.

[0192] Based on the measurement information about the channel between the second base station 20 and the terminals included in the frequency sharing terminal group, the first base station 10 may determine to change the maximum transmission power that the second base station 20 can use in order to transmit a signal using the shared frequency resource.

[0193] In step 1340 , the first base station 10 sends information on whether to stop sharing the shared frequency resources with the second base station 20 to the second base station 20 .

[0194] The first base station 10 may transmit to the second base station 20 information indicating that sharing of the shared frequency resources will be stopped, information indicating that sharing of the shared frequency resources will be maintained, and information indicating that the maximum transmission power that the second base station 20 can use to transmit a signal using the shared frequency resources has changed.

[0195] Although referenced Fig.13 An embodiment of determining whether to stop sharing frequency resources by channel measurement is described, and the first base station 10 can stop sharing the shared frequency resources in response to a request from the second base station 20. For example, when the traffic of the second terminal group decreases and the shared frequency resources do not need to be used, when the first base station 10 provides a notification that a signal needs to be sent using a power greater than the maximum transmission power in order to use the shared frequency resources, the second base station 20 can request the first base station 10 to stop sharing the frequency resources. In addition, even when the period for sharing the shared frequency resources or the condition for stopping sharing the shared frequency resources is met (already referred to Figure 8 and Fig. 9 Description), the first base station 10 may stop sharing frequency resources.

[0196] Fig.14 FIG. 1 is a flowchart of a method for determining whether to stop sharing the shared frequency resources executed by the second base station 20 according to an embodiment. Fig. 9 After the step, the second base station 20 may execute Fig.14 steps.

[0197] In step 1410, the second base station 20 receives a signal for channel measurement from a terminal included in the frequency sharing terminal group. The second base station 20 may be in a state of synchronization with the first base station 10 or the first terminal group. Therefore, the second base station 20 may not need to Fig. 9 As in step 920 of the embodiment, signal information indicating that a signal for channel measurement is to be transmitted from the first base station 10 is received.

[0198] In step 1420, the second base station 20 measures channels between the second base station and the terminals included in the frequency sharing terminal group based on the received signal for channel measurement.

[0199] The second base station 20 measures the reception strength of the received signal for channel measurement. In addition, based on the information about the maximum permissible interference level to the signal between the first base station 10 and the terminal included in the frequency sharing terminal group, the second base station 20 can measure the maximum transmission power that the second base station 20 can use to transmit the signal through each channel between the second base station 20 and the terminal included in the frequency sharing terminal group.

[0200] In step 1430, the second base station 20 sends measurement information about a channel between the second base station 20 and the terminals included in the frequency sharing terminal group to the first base station 10. Step 1430 may correspond to Fig.13 Step 1320.

[0201] In step 1440, the second base station 20 receives information from the first base station 20 on whether to stop sharing the shared frequency resources with the first base station 10. Step 1440 may correspond to Fig.13 Step 1340.

[0202] The second base station 20 may determine whether to stop using the shared frequency resources to communicate with the terminals included in the second terminal group based on the information received from the first base station 10 on whether to stop sharing the shared frequency resources. Alternatively, when receiving information from the first base station 10 indicating that the maximum transmission power that the second base station 20 can use in order to send a signal using the shared frequency resources has changed, the second base station 20 may adjust the transmission power to be used for sending a signal using the shared frequency resources.

[0203] Although referenced Fig.14 An embodiment in which whether to stop sharing frequency resources is determined by channel measurement is described, and the second base station 20 may request the first base station 10 to stop sharing the shared frequency resources.

[0204] Fig.15 is a sequential flow chart of a method for performing scheduling and data transmission and reception using a shared frequency according to one embodiment. Figure 8 and Fig. 9 In contrast to the embodiment, Fig.15 An embodiment of a method of performing scheduling and data transmission and reception using a shared frequency when the first base station 10 does not determine a frequency sharing terminal group is shown.

[0205] In step 1510, the first base station 10 schedules shared frequency resources to the first terminal 151. The first terminal 151 may be a terminal included in the first terminal group and may be a terminal that determines that it can perform communication using shared frequency resources based on channel measurement information received by the first base station 10 from the second base station 20.

[0206] In step 1520, the first base station 10 sends scheduling information to the second base station 20 using the shared frequency resources of the first terminal 151. In addition, the first base station 10 may send information about the maximum transmission power that the second base station 20 can use in order to send signals using the shared frequency resources relative to the first terminal 151 (i.e., to mitigate interference that may affect the first terminal 151) to the second base station 20.

[0207] In step 1530 , the first base station 10 sends data to the first terminal 151 and receives data from the first terminal 151 according to the scheduling of the first terminal 151 .

[0208] In step 1540, based on the maximum transmission power that the second base station 20 can use in response to the first terminal 151 using shared frequency resources to send a signal, the second base station 20 determines that the second terminal 152 will use shared frequency resources from the terminals included in the second terminal group to communicate, and uses the shared frequency resources for scheduling.

[0209] In step 1550 , the second base station 20 transmits data to the second terminal 152 and receives data from the second terminal 152 using the shared frequency resources.

[0210] refer to Fig.15 , after the second base station 20 receives the scheduling information about the first terminal 151 that is to communicate using the shared frequency from the first base station 10, the second base station 20 can determine the maximum transmission power using the shared frequency, can determine that the second terminal 152 schedules the shared frequency resource, and can send and receive data. Therefore, due to the signaling delay between the first base station 10 and the second base station 20 and the scheduling delay of the second base station 20, as long as the first base station 10 sends and receives data to and from the first terminal 151, the second base station 20 may not be able to send and receive data to and from the second terminal 152 using the shared frequency. That is, even when the second base station 20 knows the information about the frequency band of the shared frequency resource, unless the second base station 20 receives the information about the terminal that communicates using the shared frequency resource from the first base station 10, it may be difficult for the second base station 20 to actually use the shared frequency resource for communication.

[0211] Fig.16 is a sequential flow chart of a method for performing scheduling and data transmission and reception using a shared frequency according to one embodiment. Figure 8 and Fig. 9 An embodiment of Fig.16 An embodiment of a method of performing scheduling and data transmission and reception using a shared frequency when the first base station 10 determines a frequency sharing terminal group is shown.

[0212] In step 1610, the first base station 10 sends information about the shared frequency band and information about the frequency sharing terminal group as information about the shared frequency resource. Step 1610 may correspond to Figure 8 Step 850.

[0213] In step 1620 , the first base station 10 uses the shared frequency resources to schedule the (1-1)th terminal 161 included in the frequency sharing terminal group.

[0214] In step 1630, the second base station 20 uses the shared frequency resources to schedule the (2-1)th terminal 163. Step 1630 may be performed before step 1620, that is, before the first base station 10 performs scheduling using the shared frequency resources.

[0215] In step 1621, the first base station 10 uses the shared frequency resources to transmit data to the (1-1)th terminal 161 and receives data from the (1-1)th terminal 161. In addition, in step 1631, the second base station 20 uses the shared frequency resources to transmit data to the (2-1)th terminal 163 and receives data from the (2-1)th terminal 163. Data transmission and reception between the first base station 10 and the (1-1)th terminal 161 and data transmission and reception between the second base station 20 and the (2-1)th terminal 163 can be performed simultaneously.

[0216] In step 1622, the first base station 10 uses the shared frequency resources to schedule the (1-2)th terminal 162 included in the frequency sharing terminal group. In addition, in step 1623, the first base station 10 uses the shared frequency resources to send data to the (1-2)th terminal 162 and receive data from the (1-2)th terminal 162.

[0217] In step 1632, the first base station 20 uses the shared frequency resources to schedule the (2-2)th terminal 164 included in the frequency sharing terminal group. In addition, in step 1633, the second base station 20 uses the shared frequency resources to send data to the (2-2)th terminal 164 and receive data from the (2-2)th terminal 164.

[0218] refer to Fig.16, the first base station 10 and the second base station 20 can freely perform scheduling using the shared frequency resources based on the information about the shared frequency resource group. When the frequency sharing period is configured, scheduling can be freely performed within the frequency sharing period. In this way, when the first base station 10 provides the second base station 20 with information about the shared frequency resource group that will use the shared frequency resources for communication (for example, information about transmission power) in advance, the second terminal group that is to be communicated by the second base station 20 using the shared frequency resources can be predetermined, and scheduling can be freely performed as needed, regardless of the scheduling of the first base station 10.

[0219] Fig.17 FIG. 1 is a flowchart of a method for sharing frequency resources with a second base station 20 and executed by a first base station 10 according to an embodiment. Figure 8 Compared with the embodiment in Fig.17 An embodiment of performing channel measurements for sharing frequency resources based on downlink signals is presented.

[0220] In step 1710, the first base station 10 sends information indicating that a signal for channel measurement is to be sent to the second base station 20.

[0221] The first base station 10 may instruct to send a signal for channel measurement to the second base station 10, so as to share the first frequency resource with the second base station 20 and obtain measurement information about the channel between the second base station 20 and the terminal included in the first terminal group. The information instructing to send the signal for channel measurement may include information about resources to be used by the second base station 20 for sending the signal for channel measurement, information to be included in the signal for channel measurement (for example, identification information of the second base station 20 or sequence information of the signal).

[0222] In step 1720, the first base station 10 sends information indicating receiving a signal for channel measurement and sends channel measurement information to a channel measurement target terminal determined from among the terminals communicating using the first frequency resource. The channel measurement target terminal may correspond to Figure 8 The channel measurement target terminal.

[0223] The first base station 10 may transmit, to the channel measurement target terminal, information indicating that a signal for channel measurement is to be transmitted from the second base station 20. The information indicating that a signal for channel measurement is to be transmitted may include information about resources for transmitting a signal for channel measurement, information about a time at which monitoring is to be performed in order to receive a signal for channel measurement, and information about a sequence for transmitting a signal for channel measurement.

[0224] The first base station 10 may transmit information about the maximum permissible interference level (or strength) of a signal between the first base station 10 and the channel measurement target terminal based on a signal transmitted by the second base station 20 to the channel measurement target terminal. In addition, the first base station 10 may transmit information about the transmission power of the second base station 20 based on a signal transmitted by the second base station 20 to the channel measurement target terminal.

[0225] The first base station 10 may notify the channel measurement target terminal of the information that must be included in the channel measurement information. For example, based on the signal for channel measurement received from the second base station 20, the first base station 10 may request the channel measurement target terminal to measure information about the strength of the signal sent by the second base station 20 and information about the maximum transmission power (P_max (UE_ID)) that the second base station 20 can use to send a signal through each channel between the second base station 20 and the channel measurement target terminal. The first base station 10 may send this information.

[0226] In step 1730 , the first base station 10 receives measurement information on a channel between the second base station 20 and the channel measurement target terminal from the channel measurement target terminal.

[0227] The measurement information about the channel received by the first base station 10 may include information about the strength of a signal measured based on a signal sent by the second base station 20 for channel measurement, and information about the maximum transmission power (P_max(UE_ID)) that the base station 20 can use to send a signal through each channel between the second base station 20 and the channel measurement target terminal.

[0228] In step 1740, the first base station 10 determines a shared frequency resource to be shared with the second base station from the first frequency resource based on the measurement information about the channel between the second base station 20 and the channel measurement target terminal. Step 1740 may correspond to Figure 8 That is, even in the case where channel measurement is performed based on a downlink signal, the channel measurement can be performed based on an uplink signal. Figure 8 The process of determining shared frequency resources based on channel measurement information is performed as in the case of .

[0229] In step 1750, the first base station 10 sends information about shared frequency resources to the second base station 20. Step 1750 may correspond to Figure 8 Step 850.

[0230] Fig.18 FIG. 1 is a flowchart of a method for sharing frequency resources with a second base station 20 and executed by a first base station 10 according to an embodiment. Fig. 9 Compared with the embodiment in Fig.18An embodiment of performing channel measurements for sharing frequency resources based on downlink signals is presented.

[0231] In step 1810, the second base station 20 receives information indicating that a signal for channel measurement is to be transmitted from the first base station 10. Step 1810 may correspond to Fig.17 Step 1710.

[0232] In step 1820, the second base station 20 sends a signal for channel measurement.

[0233] The second base station 20 can send a signal for channel measurement based on information about resources used to send a signal for channel measurement received from the first base station 10 to be used by the second base station 20, and information to be included in the signal for channel measurement (for example, identification information of the second base station 20 or sequence information of the signal).

[0234] In step 1830, the second base station 20 receives information about shared frequency resources from the first base station 10. Step 1830 may correspond to Fig. 9 Step 950.

[0235] Fig.19 is a block diagram showing the structure of a first base station according to an embodiment.

[0236] refer to Fig.19 , the first base station includes a processor 1910, a communicator 1920, and a memory 1930. However, the elements of the first base station 10 are not limited to the above examples. For example, the first base station 10 may include more or less elements than the above elements. In addition, the processor 1910, the communicator 1920, and the memory 1930 may be implemented in the form of a single chip.

[0237] The processor 1910 may control a series of processes in which the first base station may operate according to the above-described embodiments of the present disclosure. For example, the processor 1910 may control the elements of the first base station to perform a method for dynamically sharing frequency resources in a wireless communication system. The processor 1910 may include multiple processors. The processor 1910 may execute a program stored in the memory 1930 to perform operations according to the above-described embodiments.

[0238] The communicator 1920 can send a signal to the second base station, the terminal and receive a signal from the second base station, the terminal. The signal sent and received by the communicator 1920 may include control information and data. The communicator 1920 may include an RF transmitter that performs up-conversion and amplification on the frequency of the signal to be sent, and an RF receiver that performs low-noise amplification on the received signal and performs down-conversion on the frequency of the received signal. However, the communicator 1920 is only an embodiment, and the elements of the communicator 1920 are not limited to the RF transmitter and the RF receiver. In addition, the communicator 1920 can receive a signal through a radio channel, output the signal to the processor 1910, and send the output signal of the processor 1910 through the radio channel.

[0239] The memory 1930 may store programs and data necessary for the operation of the first base station 10. In addition, the memory 1930 may store control information or data included in the signal sent and received by the first base station. The memory 1930 may include a storage medium such as a read-only memory (ROM), a random access memory (RAM), a hard disk, a compact disc read-only memory (CD-ROM), and a digital versatile disk (DVD) or any combination thereof. In addition, the memory 1930 may include a plurality of memories. The memory 1930 may store a program for performing the operation according to the above-described embodiment.

[0240] Fig. 20 is a block diagram showing the structure of a second base station according to an embodiment.

[0241] refer to Fig. 20 , the second base station includes a processor 2010, a communicator 2020, and a memory 2030. However, the elements of the second base station 20 are not limited to the above examples. For example, the second base station may include more or fewer elements than the above elements. In addition, the processor 2010, the communicator 2020, and the memory 2030 may be implemented in the form of a single chip.

[0242] The processor 2010 may control a series of processes in which the second base station may operate according to the above-described embodiments of the present disclosure. For example, the processor 2010 may control the elements of the second base station to perform a method for dynamically sharing frequency resources in a wireless communication system. The processor 2010 may include multiple processors. The processor 2010 may execute a program stored in the memory 2030 to perform operations according to the above-described embodiments.

[0243] The communicator 2020 may send a signal to the second base station and receive a signal from the second base station. The signal sent to the second base station and the signal received from the second base station may include control information and data. The communicator 2020 may include an RF transmitter that performs up-conversion and amplification on the frequency of the signal to be sent, and an RF receiver that performs low-noise amplification on the received signal and performs down-conversion on the frequency of the received signal. However, the communicator 2020 is only an embodiment, and the elements of the communicator 2020 are not limited to the RF transmitter and the RF receiver. In addition, the communicator 2020 may receive a signal through a radio channel, output the signal to the processor 2010, and send the output signal of the processor 2010 through the radio channel.

[0244] The memory 2030 may store programs and data necessary for the operation of the second base station 20. In addition, the memory 2030 may store control information or data included in the signal sent and received by the second base station 20. The memory 2030 may include a storage medium such as a ROM, a RAM, a hard disk, a CD-ROM, and a DVD, or any combination thereof. In addition, the memory 2030 may include a plurality of memories. The memory 2030 may store a program for performing the operation according to the above-described embodiment.

[0245] Frequency resources can be dynamically shared in wireless communication systems.

[0246] The embodiments of the present disclosure described in this specification and the accompanying drawings are presented only as specific examples in order to easily explain the technical content of the present disclosure and help understand the present disclosure, and are not intended to limit the scope of the present disclosure. That is, it will be apparent to those skilled in the art that other modifications can be made based on the technical ideas of the present disclosure. In addition, the various embodiments of the present invention can be combined with each other as needed. For example, certain parts of the embodiments of the present disclosure can be combined with each other so as to operate the base station and the terminal. In addition, although the embodiments of the present disclosure have been presented based on the NR system, other modifications based on the technical ideas of the embodiments of the present disclosure can also be applied to other systems, such as frequency division duplex (FDD) or time division duplex (TDD) LTE systems.

[0247] In addition, embodiments of the present disclosure have been described and shown in this specification and the drawings. Although certain terms are used herein, they are used only in a general sense to easily describe the technical ideas of the present disclosure and to help understand the present disclosure, and are not intended to limit the scope of the present disclosure.

[0248] While the present disclosure has been particularly shown and described with reference to certain embodiments thereof, it will be understood by those skilled in the art that various changes in form and details may be made without departing from the spirit and scope of the present disclosure as defined by the appended claims and their equivalents.

Claims

1. A method for sharing frequency resources with a second base station in a wireless communication system, the method comprising: Sending information indicating that a signal for channel measurement is to be sent to the second base station to one or more channel measurement target terminals, where the one or more channel measurement target terminals are determined from terminals that communicate with the first base station using a first frequency resource; Sending to the second base station information indicating that the signal for channel measurement is to be sent from the one or more channel measurement target terminals; Receiving, from the second base station, measurement information about a channel between the second base station and the one or more channel measurement target terminals, wherein the measurement information includes information related to at least one first maximum transmission power of the second base station, the at least one first maximum transmission power corresponds to the one or more channel measurement target terminals, and the at least one first maximum transmission power is determined by the second base station; determining, from the first frequency resources, a shared frequency resource to be shared with the second base station based on the measurement information about the channel between the second base station and the one or more channel measurement target terminals; and sending information about the shared frequency resource to the second base station, The at least one first maximum transmission power is determined based on information related to a maximum allowed interference level.

2. The method of claim 1, wherein: Determining the shared frequency resource includes: determining, based on the information related to the at least one first maximum transmission power, a second maximum transmission power of the second base station when the second base station uses the shared frequency resource, The information related to the shared frequency resource includes information related to the second maximum transmission power.

3. The method according to claim 1, wherein the information indicating that the signal for channel measurement is to be transmitted comprises at least one of information about a resource for transmitting the signal for channel measurement or information about a sequence to be used for transmitting the signal for channel measurement, and The resource used to send the signal for channel measurement includes symbols of a certain duration or longer.

4. The method of claim 1, wherein the information indicating that the signal for channel measurement is to be sent includes at least one of information related to resources used to send the signal for channel measurement, information related to a time at which monitoring is to be performed in order to receive the signal for channel measurement, or information related to a sequence used to send the signal for channel measurement.

5. The method of claim 1, wherein the information indicating that the signal for channel measurement is to be sent includes information related to a maximum allowable interference level to a signal between the first base station and the one or more channel measurement target terminals caused by a signal sent by the second base station.

6. The method of claim 1, wherein determining the shared frequency resource comprises: determining a frequency sharing terminal group including terminals communicating with the first base station using the shared frequency resources from among the terminals communicating with the first base station using the first frequency resources; and determining, based on the frequency sharing terminal group, a second maximum transmission power of the second base station when the second base station uses the shared frequency resource, The information about the shared frequency resource includes at least one of information about a frequency band of the shared frequency resource, information about the frequency sharing terminal group, or information about the second maximum transmission power. 7 . The method of claim 6 , wherein the frequency sharing terminal group is determined based on at least one of the measurement information about a channel or information about a location of a terminal communicating with the first base station using the first frequency resource.

8. A method for sharing frequency resources with a first base station in a wireless communication system, the method comprising: receiving, from the first base station, information indicating that one or more channel measurement target terminals are to send signals for channel measurement, the one or more channel measurement target terminals being determined from terminals communicating with the first base station using a first frequency resource; receiving the signal for channel measurement from the one or more channel measurement target terminals; Measuring a channel between the second base station and the one or more channel measurement target terminals based on the signal for channel measurement and information indicating that the signal for channel measurement is to be sent, wherein measuring the channel includes determining at least one first maximum transmission power of the second base station corresponding to the one or more channel measurement target terminals; Sending measurement information about a channel between the second base station and the one or more channel measurement target terminals to the first base station, wherein the measurement information includes information related to the at least one first maximum transmission power of the second base station; and receiving, from the first base station, information about a shared frequency resource in the first frequency resource that the first base station will share with the second base station, wherein the shared frequency resource is determined based on the measurement information about a channel between the second base station and the one or more channel measurement target terminals, The at least one first maximum transmission power is determined based on information related to a maximum allowed interference level.

9. The method of claim 8, wherein: The information related to the shared frequency resource includes: a second maximum transmission power of the second base station when the second base station uses the shared frequency resource, and The second maximum transmission power is determined based on the at least one first maximum transmission power.

10. The method of claim 8, wherein the information indicating that the signal for channel measurement is to be transmitted comprises at least one of information about a resource for transmitting the signal for channel measurement, information about a time at which monitoring is to be performed in order to receive the signal for channel measurement, or information about a sequence for transmitting the signal for channel measurement, and The resource used to send the signal for channel measurement includes symbols of a certain duration or longer.

11. The method of claim 10, wherein receiving the signal for channel measurement comprises: monitoring a signal based on the information about the resource used to transmit the signal for channel measurement and the information about the time at which monitoring is to be performed in order to receive the signal for channel measurement; as well as The signal used for channel measurement is obtained from the monitored signal.

12. The method of claim 8, wherein the information indicating that the signal for channel measurement is to be sent includes information related to a maximum allowable interference level caused by a signal sent by the second base station to a signal between the first base station and the one or more channel measurement target terminals.

13. The method of claim 8, wherein the information about the shared frequency resource comprises at least one of information about a frequency band of the shared frequency resource, information about a frequency sharing terminal group, or information about a second maximum transmission power of the second base station when the second base station uses the shared frequency resource, wherein the frequency sharing terminal group includes terminals that communicate with the first base station using the shared frequency resources from among the terminals that communicate with the first base station using the first frequency resources, and in, The second maximum transmission power is determined based on the frequency sharing terminal group. 14 . The method of claim 13 , wherein the frequency sharing terminal group is determined based on at least one of the measurement information about a channel or information about a location of the terminal communicating with the first base station using the first frequency resource.

15. A first base station for sharing frequency resources with a second base station in a wireless communication system, the first base station comprising: communicator; Memory; as well as at least one processor connected to the communicator and configured to: Sending information indicating that a signal for channel measurement is to be sent to the second base station to one or more channel measurement target terminals, where the one or more channel measurement target terminals are determined from terminals that communicate with the first base station using a first frequency resource; Sending to the second base station information indicating that the signal for channel measurement is to be sent from the one or more channel measurement target terminals; Receiving, from the second base station, measurement information about a channel between the second base station and the one or more channel measurement target terminals, wherein the measurement information includes information related to at least one first maximum transmission power of the second base station, the at least one first maximum transmission power corresponds to the one or more channel measurement target terminals, and the at least one first maximum transmission power is determined by the second base station; determining, from the first frequency resources, a shared frequency resource to be shared with the second base station based on the measurement information about the channel between the second base station and the one or more channel measurement target terminals; and sending information about the shared frequency resource to the second base station, The at least one first maximum transmission power is determined based on information related to a maximum allowed interference level.

16. A second base station for sharing frequency resources with a first base station in a wireless communication system, the second base station comprising: communicator; Memory; as well as at least one processor connected to the communicator and configured to: receiving, from the first base station, information indicating that one or more channel measurement target terminals are to send signals for channel measurement, the one or more channel measurement target terminals being determined from terminals communicating with the first base station using a first frequency resource; receiving the signal for channel measurement from the one or more channel measurement target terminals; Measuring a channel between the second base station and the one or more channel measurement target terminals based on the signal for channel measurement and information indicating that the signal for channel measurement is to be sent, wherein measuring the channel includes determining at least one first maximum transmission power of the second base station corresponding to the one or more channel measurement target terminals; Sending measurement information about a channel between the second base station and the one or more channel measurement target terminals to the first base station, wherein the measurement information includes information related to the at least one first maximum transmission power of the second base station; and receiving, from the first base station, information about a shared frequency resource to be shared with the second base station from among the first frequency resources, the shared frequency resource being determined based on the measurement information about a channel between the second base station and the one or more channel measurement target terminals, The at least one first maximum transmission power is determined based on information related to a maximum allowed interference level.

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