Method and apparatus for allocating resource blocks to cell group in vran

Abstract

Looking back on the evolution of wireless communication across successive generations, technologies have primarily been developed for human-oriented services, including voice, multimedia, and data. The present disclosure provides a method for allocating resource blocks (RBs) to at least one cell group operated by a virtualized radio access network (vRAN), the method comprising: an operation of determining, on the basis of RB requirements for the at least one cell group, interference-concentrated RBs and interference-free RBs arranged at different, non-overlapping positions along a frequency axis; and an operation of allocating the determined interference-concentrated RBs and interference-free RBs to the at least one cell group, wherein the interference-concentrated RBs are RBs used for transmission in all of the cell groups, and the interference-free RBs are RBs not used for transmission in at least some of the cell groups.

Description

Method and device for allocating resource blocks to cell groups in VRAN

[0001] The present disclosure relates to a method and apparatus for allocating resource blocks, and more specifically, to a method and apparatus for allocating resource blocks in a vRAN environment.

[0002] Looking back at the evolution of wireless communication through successive generations, technologies have been developed primarily for human-oriented services, such as voice, multimedia, and data. Following the commercialization of 5G (5th-generation) communication systems, connected devices, which have been increasing explosively, are expected to be connected to communication networks. Examples of networked objects include vehicles, robots, drones, home appliances, displays, smart sensors installed in various infrastructures, construction machinery, and factory equipment. Mobile devices are expected to evolve into various form factors, such as augmented reality glasses, virtual reality headsets, and holographic devices. In the 6G (6th-generation) era, efforts are underway to develop improved 6G communication systems to connect hundreds of billions of devices and objects to provide diverse services. For this reason, 6G communication systems are referred to as "beyond 5G" systems.

[0003] In the 6G communication system predicted to be realized around 2030, the maximum transmission speed is tera (i.e., 1,000 gigabits) bps, and the wireless latency is 100 microseconds (μsec). In other words, compared to the 5G communication system, the transmission speed in the 6G communication system is 50 times faster, and the wireless latency is reduced to one-tenth.

[0004] To achieve such high data transmission speeds and ultra-low latency, 6G communication systems are being considered for implementation in the terahertz band (e.g., the 95 GHz to 3 terahertz (3 THz) band). In the terahertz band, due to more severe path loss and atmospheric absorption compared to the millimeter wave (mmWave) band introduced in 5G, the importance of technology capable of guaranteeing signal reach, or coverage, is expected to increase. As key technologies to ensure coverage, radio frequency (RF) devices, antennas, new waveforms that offer better coverage than orthogonal frequency division multiplexing (OFDM), beamforming, and multi-antenna transmission technologies such as massive multiple-input and multiple-output (massive MIMO), full-dimensional MIMO (FD-MIMO), array antennas, and large-scale antennas must be developed. In addition, new technologies are being discussed to improve coverage of terahertz band signals, including metamaterial-based lenses and antennas, high-dimensional spatial multiplexing technology using orbital angular momentum (OAM), and reconfigurable intelligent surface (RIS).

[0005] In addition, to improve frequency efficiency and system network, development is underway in 6G communication systems for full duplex technology, in which uplink and downlink simultaneously utilize the same frequency resources at the same time; network technology that integrates satellites and HAPS (high-altitude platform stations); network structure innovation technology that supports mobile base stations and enables network operation optimization and automation; dynamic spectrum sharing technology through collision avoidance based on spectrum usage prediction; AI-based communication technology that utilizes AI (artificial intelligence) from the design stage and internalizes end-to-end AI support functions to realize system optimization; and next-generation distributed computing technology that realizes services of complexity exceeding the limits of terminal computing capabilities by utilizing ultra-high performance communication and computing resources (mobile edge computing (MEC), cloud, etc.). In addition, attempts are continuing to further strengthen connectivity between devices, further optimize networks, promote the softwareization of network entities, and increase the openness of wireless communication through the design of new protocols to be used in 6G communication systems, the implementation of hardware-based security environments, the development of mechanisms for the safe utilization of data, and the development of technologies regarding privacy maintenance methods.

[0006] Due to the research and development of such 6G communication systems, it is expected that a new dimension of hyper-connected experience will become possible through the hyper-connectivity of 6G communication systems, which encompasses not only connections between objects but also connections between people and objects. Specifically, it is projected that 6G communication systems will enable the provision of services such as truly immersive extended reality (truly immersive XR), high-fidelity mobile holograms, and digital replicas. Furthermore, services such as remote surgery, industrial automation, and emergency response, which are provided through 6G communication systems with enhanced security and reliability, will be applied in various fields including industry, healthcare, automotive, and home appliances.

[0007] vRAN systems often fail to adequately consider frequency allocation for each cell when distributing complexity. Among cells using the same band, the frequency assigned to a terminal directly affects various performance indicators, such as frequency efficiency, interference levels, and transmission capacity. However, if resources are distributed without sufficiently considering the differences in frequency allocation between cells when distributing RBs, there are limitations in optimizing the overall performance of the system.

[0008] In vRAN, if resources are distributed simply based on inter-cell traffic load or service requirements, or if approaches to interference management based on frequency bands or optimization of frequency efficiency are not implemented, inefficient resource allocation may occur, such as network performance degradation due to reduced frequency efficiency in some cells and excessive resource waste in others.

[0009] The present disclosure provides a method for allocating resource blocks (RBs) to at least one group of cells operated by a virtualized radio access network (vRAN), comprising: determining interference concentrated RBs and interference free RBs that are non-overlappingly placed at different locations on the frequency axis based on RB requirements for the at least one group of cells; and allocating the determined interference concentrated RBs and interference free RBs to the at least one group of cells, wherein the interference concentrated RBs are RBs used for transmission in all of the at least one group of cells, and the interference free RBs are RBs not used for transmission in some of the at least one group of cells.

[0010] The present disclosure provides a virtualized radio access network (vRAN) device for allocating resource blocks (RBs) to at least one cell group, comprising: a transceiver; and at least one processor, wherein the at least one processor is configured to determine an interference concentrated RB and an interference free RB that are non-overlappingly positioned at different locations on the frequency axis based on RB requirements for the at least one cell group operated by the vRAN, and to allocate the determined interference concentrated RB and interference free RB to the at least one cell group, wherein the interference concentrated RB is an RB used for transmission in all of the at least one cell group, and the interference free RB is an RB not used for transmission in some of the at least one cell group.

[0011] The present disclosure provides a method for configuring user equipment (UE) at a base station within at least one cell group operated by a virtualized radio access network (vRAN), comprising: transmitting configuration information to the UE that specifies a time interval for allocating interference concentrated RBs and interference free RBs that are non-overlappingly positioned at different locations on the frequency axis; and receiving a channel quality information (CQI) report measured based on the configuration information, wherein the interference concentrated RB is an RB used for transmission in all of the at least one cell group, and the interference free RB is an RB not used for transmission in some of the at least one cell group.

[0012] In vRAN, if a resource allocation method tailored to the frequency band characteristics of each cell is introduced, frequency interference can be minimized, network capacity maximized, and system performance ultimately improved by more effectively utilizing the characteristics of each cell's frequency band.

[0013] Through the present disclosure, the impact of interference can be minimized when allocating L1 computing resources in vRAN, thereby maximizing the frequency efficiency of the resources.

[0014] FIG. 1 is a diagram illustrating a virtual radio access network (vRAN) according to one embodiment of the present disclosure.

[0015] Figure 2 is a diagram illustrating the computing resources required in a single vRAN by multiple cells.

[0016] Figure 3 is a diagram illustrating a case where vRAN distributes computing resources to multiple cells.

[0017] Figure 4 is a diagram showing an example of efficient resource allocation per cell.

[0018] Figure 5 is a diagram showing an example of an interference-free RB and an interference-concentrated RB.

[0019] FIG. 6a is a diagram illustrating a method for defining interference-free RBs and interference-concentrated RBs when only one cell exists per cell group.

[0020] FIG. 6b is a diagram illustrating a method for defining interference-free RBs and interference-concentrated RBs when there are multiple cells per cell group.

[0021] Figure 7 is a diagram illustrating a method of forming cell groups within a single DU.

[0022] Figure 8 is a diagram illustrating a method of forming cell groups within a plurality of DUs.

[0023] FIG. 9 is a diagram illustrating a method for setting interference-free RB and interference-concentrated RB when the required CPRB amounts of given cell groups are the same, according to one embodiment of the present disclosure.

[0024] FIG. 10 is a diagram illustrating a method for setting interference-free RB and interference-concentrated RB when the required CPRB amounts of given cell groups are different, according to one embodiment of the present disclosure.

[0025] FIG. 11 is a diagram illustrating an interference-free RB setting method when the required CPRB amounts of given cell groups are different, according to one embodiment of the present disclosure.

[0026] FIG. 12 is a diagram illustrating a method for setting primary interference RB and interference concentration RB when the required CPRB amounts of given cell groups are different, according to one embodiment of the present disclosure.

[0027] Figure 13a illustrates how vRAN distributes interference-free RBs according to the requirements of each cell group.

[0028] Figure 13b illustrates that vRAN distributes interference-free RBs evenly to each cell group.

[0029] Figure 13c illustrates how vRAN distributes interference-free RBs to each cell group using the time division multiplexing (TDM) method.

[0030] Figures 14a, 14b, and 14c illustrate the changes in the interference-free RB operation status of vRAN based on the resource utilization rate within the DU of vRAN.

[0031] Figure 14a illustrates the state change diagram when only the On / Off state of the interference-free RB operation is present.

[0032] Figure 14b illustrates the state change diagram when additional conditions other than the resource utilization rate within the DU of vRAN are considered.

[0033] Figure 14c illustrates the state change diagram when operating in an interference-free RB operation state and a primary interference RB operation state.

[0034] Figures 15a and 15b are diagrams illustrating a method of applying the interference-free RB operating mode differently over time.

[0035] FIG. 15a is a diagram illustrating a pre-defined slot setting without on / off triggering.

[0036] FIG. 15b is a diagram illustrating how a pre-defined slot set is set to RRC and then some of it is turned on / off to DCI (downlink control indicator), MAC (medium access control), CE (control element), etc.

[0037] Figure 16 is a diagram showing the signal-to-interference and noise ratio (SINR) by interference-free RB and interference-focused RB.

[0038] Figure 17 is a diagram illustrating the CSI-RS reporting method.

[0039] FIG. 18 is an exemplary diagram of a method for distributing resource blocks in terms of vRAN according to an embodiment of the present disclosure.

[0040] FIG. 19 illustrates the structure of a vRAN device according to an embodiment of the present disclosure.

[0041] Among the various technologies aimed at maximizing the efficiency and performance of mobile communication networks, the virtualized radio access network (vRAN) is a technology that virtualizes the radio access network to increase network flexibility and enable efficient resource management. The introduction of vRAN signifies a technological advancement in terms of network flexibility, scalability, and cost efficiency, and contributes to future 6G and subsequent mobile communication technologies.

[0042] In traditional radio access networks (RANs), various base station functions were implemented relying on dedicated hardware equipment; however, this reliance on hardware equipment imposed limitations on system flexibility and scalability. vRAN implements part or all of the radio access network in software on commercial off-the-shelf (COTS) hardware, thereby providing functions such as dynamic resource allocation, network slicing, and centralized management. vRAN enables network operators to reduce operational expenditures (OPEX) and provides services that meet diverse user demands.

[0043] vRAN can be broadly composed of a central unit (CU), a distributed unit (DU), and a radio unit (RU). The CU and the DU are software-implemented functions that can be flexibly deployed at various physical locations through network function virtualization (NFV) technology. The CU can primarily handle higher-level protocols, while the DU can handle lower-level protocols requiring real-time processing. Additionally, the RU is responsible for the transmission and reception of actual radio signals and can perform the role of a base station in a traditional RAN. In this disclosure, vRAN may be used with the same meaning as a base station in the traditional sense or with a different meaning. For example, since a CU or DU implemented in software by vRAN can perform the role of operating or scheduling an RU corresponding to a base station in the traditional sense, vRAN may have a different meaning from a base station. Meanwhile, since a single vRAN is an entity operating multiple RUs, i.e., base stations, the base station and vRAN are considered as a single entity, the vRAN may have the same meaning as the base station. In this disclosure, the term 'cell' is assumed to be a concept serviced by a single 'base station' and the terms are used separately, but examples have been provided where they have the same meaning.

[0044] FIG. 1 is a diagram illustrating a virtual radio access network (vRAN) according to one embodiment of the present disclosure.

[0045] vRAN (102) is a virtualization technology that applies virtualization technology to the wireless network domain to maximize efficiency by integrating processing functions that were previously performed at each base station into a general-purpose server (e.g., located in a centralized center). Virtualization of the RAN can be achieved through Network Function Virtualization (NFV) operations, in which case the RAN can be executed on a general-purpose server without special proprietary hardware.

[0046] In one embodiment, the vRAN (102) may be connected to a core network (101). Referring to FIG. 1, the vRAN (102) may include a centralized unit (CU) (120). The vRAN (102) may further include at least one DU (131, 132, 135) connected to the CU (120). The vRAN (102) may further include at least one RU (141, 142, 143, 144, 145, 146) connected to at least one DU (131, 132, 135). The vRAN (102) may include a schedule coordinator that schedules the wireless resources of at least one DU (131, 132, 135).

[0047] With the introduction of vRAN(102), mobile communication networks can provide the following effects.

[0048] The introduction of vRAN (102) brings about increased flexibility. vRAN (102) is combined with software-defined network (SDN) technology to enable dynamic allocation and optimization of network resources. As a result, network resources can be flexibly distributed according to changes in traffic.

[0049] In addition, there is also an effect of reducing operating costs. Compared to existing dedicated hardware-based RANs, vRAN (102) runs on general-purpose hardware, so it results in cost savings such as initial investment costs and maintenance costs.

[0050] In addition, the introduction of vRAN (102) has the effect of enabling scalability and centralized management. Centralization of network functions allows network operators to manage the network efficiently and provides network scalability. By reallocating functions between the CU (120) and the DU (131, 132, 135) or allocating additional resources as needed, network operators can respond quickly to a sudden increase in traffic.

[0051] In addition, the introduction of vRAN (102) has the effect of enabling quality of service assurance. vRAN (102) can ensure the quality of service (QoS) required for various services through network slicing. For example, vRAN (102) can maximize the quality of service by allocating optimized network resources to application services requiring ultra-low latency (ULL) and services requiring high volume of traffic, respectively.

[0052] In addition, the introduction of vRAN (102) has the effect of enabling intelligent network operation. vRAN (102) can be easily combined with machine learning (ML) and artificial intelligence (AI)-based network optimization technologies, thereby maximizing network operation efficiency. Optimal allocation of network resources and fault recovery are possible based on real-time traffic analysis.

[0053] A single vRAN (102) that implements CU (120) and DU (131, 132, 135) in software can support multiple cells. Network operators can manage multiple cells in various environments using a single vRAN (102) system. However, the number of cells that can be supported by a single vRAN (102) is determined by the processing performance and complexity of the general-purpose hardware on which the vRAN (102) runs. That is, the higher the performance of the vRAN (102) hardware, the more cells can be supported, but conversely, if the hardware resources are limited, the number of cells may be limited.

[0054] Additionally, vRAN (102) has a structure that allows multiple cells to share computing resources in order to manage the wireless network more efficiently. This structure enables cells to distribute and use required computing resources in real time, and if a specific cell lacks computing resources, more computing resources can be distributed to that specific cell to enable operation. Through the resource sharing and real-time resource distribution, vRAN (102) can optimize network performance and provides the flexibility to dynamically adjust the network according to traffic patterns or user requirements. However, the total amount of computing resources used by all cells cannot exceed the maximum computing capacity of the vRAN (102) hardware.

[0055] Figure 2 is a diagram illustrating the computing resources required in a single vRAN by multiple cells.

[0056] In FIG. 2, vRAN (102) is exemplified as operating in a 20 MHz bandwidth and providing computing resources capable of encoding 106 RBs (Resource blocks) of PDSCH (physical downlink shared channel) from each of the 8 cells in a 4-layer MIMO antenna environment with 4 transmitters and 4 receivers. To process all the requirements from the 8 cells, the vRAN (102) computes 848 RBs. However, the vRAN (102) may not be able to fully support the total requirements from the 8 cells. Depending on the hardware of the vRAN (102), the percentage of requirements from the cells that can be supported will vary. Note that the number of computing resources exemplified in FIG. 2 is merely an example.

[0057] Figure 3 is a diagram illustrating a case where vRAN distributes computing resources to multiple cells.

[0058] The present disclosure describes resources that a vRAN can allocate to one or more cells in units of RBs, and said RBs may be referred to as computational resource blocks (CPRBs). The present disclosure describes a method for distributing computing resources based on CPRBs. For example, the total amount of (computational) complexity allocated to the L1 (layer 1) functions of the vRAN may be converted into said CPRBs and distributed to each base station. Since said L1 functions are implemented in vRAN, they may be referred to as vL1 (virtualized L1). For example, if an L1 modem supports X RBs with four layers, the total number of RBs may be limited to X RBs with four layers. (RBs with one, two, or three layers may be converted into RBs with four layers.) The said CPRB may be used as a substitute concept for RBs (resource blocks), which are resources in the frequency and time axes used in base stations.

[0059] More specifically, the complexity consumed by the L1 functions (e.g., PDSCH encoding) implemented in the vRAN DU (131, 132, 135) is a value determined by the length of the encoding bits, the number of transport layers, etc., but can generally be replaced by a value that increases proportionally to the length of the RB allocated to each cell. Thus, the maximum complexity supported by vRAN is converted into the RB (resource block), and the cells belonging to vRAN can share and allocate the RB. vRAN can distribute the total supported RBs within the limits given to each cell. The amount of RBs in each cell may change depending on the result of the distribution. At this time, the total number of supported RBs and fair resource allocation (pair resource allocation) may be considered.

[0060] For example, as shown in Figure 3, assuming that vRAN supports up to 28 RBs and up to 4 cells (or base stations), an example is given in which each cell is allocated 8, 4, 10, and 6 RBs, respectively, as shown in the part inside the bold box. In this case, each cell (or base station) can freely allocate and use the corresponding RBs in the frequency domain.

[0061] Figure 4 is a diagram showing an example of efficient resource allocation per cell.

[0062] For example, as shown in Fig. 4, 15 resource blocks (RBs) can be equally allocated to each cell (cell #0, cell #1), and it can be assumed that the bandwidth of each cell is 20 RBs. Each cell can allocate RBs to user equipment (UEs) within the cell by using different starting points.

[0063] Within the cell, there may be center UEs (401, 403) and edge UEs (405, 407). In the example of FIG. 4, the edge UEs (405, 407) measured a received SINR of 0 dB when interference was present (e.g., when another UE from Cell #1 was assigned to a resource assigned to a UE from Cell #0), and a received SINR of 5 dB when interference was not present (e.g., when another UE from Cell #1 was not assigned to a resource assigned to a UE from Cell #0).

[0064] In the environment of Fig. 4, the center UE (401, 403) measured a received SINR of 20 dB when interference was present (e.g., when another UE from Cell #1 was assigned to a resource assigned to a UE from Cell #0), and a received SINR of 22 dB when interference was not present (e.g., when another UE from Cell #1 was not assigned to a resource assigned to a UE from Cell #0).

[0065] Assuming that 10 RBs are allocated to the center UE (401, 403) and 5 RBs to the edge UE (405, 407) in each cell, other allocation cases can be considered as shown in FIG. 4.

[0066] Case 1: 10 RBs are allocated to the center UE (401, 403) of each cell, and 5 RBs can be allocated to the edge UE (405, 407) of each cell from the remaining RB resource area. To reduce the interference effect between cells, the scheduling starting RBs of the 10 RBs to be allocated to the center UE (401, 403) of each cell can be staggered (differently arranged). In Case 1 of FIG. 4, the starting RB to be allocated to the center UE (401, 403) of cell #0 is RB 0 (401), and the starting RB to be allocated to the center UE (401, 403) of cell #1 is RB 10 (403).

[0067] Case 2: For the center UE (401, 403) of each cell, the interference effect is small, so RBs are arranged in a concentrated manner so that interference can affect each other. In this disclosure, RBs assigned to other cells that can interfere with one's own cell, i.e., RBs used for transmission in multiple cells are assigned, are referred to as interference concentrated RBs. For the edge UE (405, 407) of each cell, the interference effect is large (compared to the center UE (401, 403)), so RBs are arranged to avoid interference as much as possible. In this disclosure, RBs assigned to frequency resources not used for transmission in some of at least one cell group are referred to as interference free RBs so that RBs assigned to other cells do not interfere with one's own cell.

[0068] As shown in Figure 4, when assigned to Case 2, gains can be obtained in the arithmetic mean of the UE (user equipment) throughput. For example, in the table in Figure 4, the arithmetic mean (Average) is 37.44 for Case 1 and 38.45 for Case 2, so there is a gain in the arithmetic mean. Case 2 can also obtain a large gain in the geometric mean (gMean in the table in Figure 4), which represents the utility of the UE throughput. Generally, since the PF (proportional fair) scheduler used in base station schedulers is a scheduler designed to maximize the geometric mean, obtaining a large gain in the geometric mean may be more important.

[0069] Figure 5 is a diagram showing an example of an interference-free RB and an interference-concentrated RB.

[0070] In Figures 5(a) and 5(b), it is assumed that 8 RBs are assigned to cell G(group) #0, 5 to cell G#1, and 3 to cell G#2.

[0071] In FIG. 5(b), in order to create an interference-free RB, the blocks in FIG. 5(a) can be moved to create a section from the 5th to 10th section from the left where the blocks are arranged so as not to overlap with other cells. The section where the blocks are arranged so as not to overlap may be a section where an interference-free RB exists.

[0072] In FIG. 5(c), it is assumed that 6 RBs are assigned to cell G#0, 6 to cell G#1, and 6 to cell G#2. Here, there may be sections in the 5th to 10th section from the left where blocks are arranged so as not to overlap with other cells. The above sections where blocks are arranged so as not to overlap may be sections where interference-free RBs exist.

[0073] Figures 6a and 6b are diagrams regarding the method of defining interference-free RBs and interference-concentrated RBs.

[0074] FIG. 6a is a diagram illustrating a method for defining interference-free RBs and interference-concentrated RBs when only one cell exists per cell group.

[0075] In relation to one embodiment of the present disclosure, cells belonging to a vRAN may form a cell group. In the present disclosure, a cell group may be a group of cells that are allocated frequency domain resources in the same form. A cell group may be established based on a Cell ID. For example, cells with the same remainder (i.e., modulo operation) value when a Cell ID is divided by a specific value may be established as a single group. The specific value may be, for example, the number of cell groups. A cell group may include at least one cell. It should be noted that in the present disclosure, when the number of 'cells' included in each of the 'cell groups' is one, the term 'cell group' may be replaced with 'cell'.

[0076] For example, assuming that three base stations serving three different cell groups belong to a single vRAN and that the three base stations belonging to the vRAN share the CPRB supported by the vRAN, an example such as FIG. 6a can be considered for the case where the CPRB requirement calculated from the traffic demand of each base station exceeds a specific threshold. The base stations belonging to a single vRAN may be base stations using the same frequency band.

[0077] FIG. 6b is a diagram illustrating a method for defining interference-free RBs and interference-concentrated RBs when there are multiple cells per cell group.

[0078] As shown in Figures 6a and 6b, the bandwidth of each cell is total RBs, and each cell may have a required amount of CPRB equal to X RBs.

[0079] Cells belonging to cell group 0 may have interference-concentrated RBs from 0 to total RB*(1.5X-50) / 100, and interference-free RBs from total RB*(1.5X-50) / 100 to total RB*X / 100.

[0080] Cells belonging to cell group 1 may have interference-concentrated RBs from 0 to total RB*(1.5X-50) / 100, and interference-free RBs from total RB*X / 100 to total RB*(150-1.5X) / 100.

[0081] Cells belonging to cell group 2 may have interference-concentrated RBs from 0 to total RB*(1.5X-50) / 100, and interference-free RBs from total RB*(150-1.5X) / 100 to total RB.

[0082] As described above, when RBs are arranged according to the methodology exemplified in FIGS. 6a and 6b, they are divided into an interference concentrate RB area shown on the left and an interference free RB area shown individually on the right.

[0083] Alternatively, the arrangement order of the interference-focused RB region and the interference-free RB region is not limited to the examples in FIG. 6a and FIG. 6b, and the interference-free RB region may be placed first (i.e., on the left) on the frequency axis, and the interference-focused RB region may be placed after (i.e., on the right) the interference-free RB region.

[0084] At this time, the cells belonging to cell group 0 may have interference-concentrated RBs from total RB*(150-1.5X) / 100 to total RB, and interference-free RBs from 0 to total RB*(50-0.5X) / 100.

[0085] Cells belonging to cell group 1 may have interference-concentrated RBs ranging from total RB*(150-1.5X) / 100 to total RB, and interference-free RBs ranging from total RB*(50-0.5X) / 100 to total RB*(200-3X) / 100.

[0086] Cells belonging to cell group 2 may have interference-concentrated RBs ranging from total RB*(150-1.5X) / 100 to total RB, and interference-free RBs ranging from total RB*(200-3X) / 100 to total RB*(150-1.5X) / 100.

[0087] In an interference-intensive RB, all cells (or base stations) belonging to the vRAN perform transmission, and in an interference-free RB, only one of the cells (or base stations) belonging to the vRAN can exclusively occupy and use the resource. That is, the interference-intensive RB defined in the present disclosure corresponds to an RB where all coordinating cells (or base stations) transmit, and thus the terminal may feel relatively significant interference, and the interference-free RB corresponds to an RB where only some of the coordinating cells (or base stations) transmit, and thus the terminal is less affected by interference.

[0088] In the present disclosure, cooperative cell groups may be assumed to use the same frequency resource. Optionally, cooperative cell groups may be determined such that the cells belonging to said cell groups are geographically adjacent to each other. (See FIG. 6b)

[0089] Figure 7 is a diagram illustrating a method of forming cell groups within a single DU.

[0090] A cell group can be defined within a single DU implemented in vRAN. As shown in FIG. 7, one or more cell groups (701, 702, 703) serviced by the DU (710) may be included within a single DU (710).

[0091] Figure 8 is a diagram illustrating a method of forming cell groups within a plurality of DUs.

[0092] Cell groups may be defined among multiple DUs implemented in a single vRAN. The interference-free RB allocation method proposed in this disclosure may be applied to the same cell group (e.g., cell group 0) belonging to different DUs, but it is preferable that the amount of frequency resources used by the cells (801, 803, 805) included in the cell group be set equally. The method proposed in this disclosure may also be applied to cases where the amount of frequency resources used by the cells (801, 803, 805) belonging to the cell group is different, but in this case, the RB resource allocation pattern may be determined based on the maximum frequency resource among the cells within a specific cell group supported by the DU.

[0093] FIG. 9 is a diagram illustrating a method for setting interference-free RB and interference-concentrated RB when the required CPRB amounts of given cell groups are the same, according to one embodiment of the present disclosure.

[0094] For example, a method for setting interference-concentrated RBs and interference-free RBs is illustrated when the required CPRB amount or loading of the cell groups is the same as X, and the maximum RB amount transmittable in each cell group, determined by the cell bandwidth, is M. In FIG. 9, it is assumed that the vRAN consists of three cell groups (901, 903, 905).

[0095] At this time, the total CPRB required by all cell groups is 3X, and the total bandwidth RB corresponds to 3M. If calculated assuming that cell group 0 (901) uses M RB, the remaining RB available to cell group 1 (903) and cell group 2 (905) is 3X-M RB, and if calculated assuming that the remaining RB is divided between cell groups 1 and 2, each is allocated 3X / 2 -M / 2 RB as a resource. In the present disclosure, the 3X / 2 -M / 2 RB can be set as RB commonly used by all cell groups, that is, interference-concentrated RB.

[0096] If the resources allocated to each cell group are arranged in an arbitrary order (e.g., in order of lowest frequency or highest frequency), 3X / 2 - M / 2 RB (i.e., 1.5XM / 2 RB) becomes an interference-concentrated RB, and the remaining RBs in cell group 0 excluding the interference-concentrated RB, i.e., M - (1.5XM / 2) RBs = 1.5M - 1.5X RB, can become interference-free RBs.

[0097] If the vRAN divides the interference-free RB, 1.5M - 1.5X RB, equally into three parts and distributes M / 2 - 0.5X RB to cell groups 0, 1, and 2, the interference-concentrated RB and interference-free RB can be distributed as shown in Fig. 9.

[0098] An example of a method for determining the starting index and ending index of the interference-free RB and interference-concentrated RB for each cell group is as follows.

[0099] Since the interference concentration RB is distributed so that cell groups use the same frequency resources despite interference, the start and end positions of the interference concentration RB can be set identically for each cell group 0, 1, and 2 (901, 903, 905).

[0100] For example, the start of the interference-focused RB of cell groups 0, 1, and 2 (901, 903, 905) may be 0 RB, and the end of the interference-focused RB may be 1.5X - M / 2 RB. The example of the start and end RBs of the interference-focused RB can be applied in the same way when mapping from a PRB (physical resource block) to a VRB (virtual resource block).

[0101] For cell group 0, the starting position of the interference-free RB can be the same position as the end point of the interference-concentrated RB, which is 1.5X - M / 2 RB. The ending position of the interference-free RB of cell group 0 can be (1.5X - M / 2) + (M / 2-0.5X) RB, i.e., X RB.

[0102] For cell group 1, the starting position of the interference-free RB can be X RB. The ending position of the interference-free RB of cell group 1 can be X RB + (M / 2-0.5X) RB, that is, 0.5X + M / 2 RB.

[0103] For cell group 2, the starting position of the interference-free RB can be 0.5X + M / 2 RB. The ending position of the interference-free RB of cell group 2 can be M RB.

[0104] If the starting position value of the interference-free RB is a decimal value, a ceiling operation (e.g., ceiling operation) may be applied to the decimal value. Therefore, in the present disclosure, the combined area of ​​the interference-concentrated RB area and the interference-free RB area is not limited to a specific value (e.g., M), but may be designed to additionally include a margin area (e.g., 3 RBs) that assumes a sequential ceiling operation corresponding to the number of starting positions of the interference-free RB (e.g., 3).

[0105] FIGS. 10 and 11 are drawings illustrating a method for setting interference-free RB and interference-concentrated RB when the required CPRB amounts of given cell groups are different, according to one embodiment of the present disclosure.

[0106] In FIG. 10, a method for setting interference-concentrated RBs and interference-free RBs is illustrated when the required CPRB amounts (or loads) of given cell groups 0, 1, and 2 are different as X, Y, and Z, respectively, and the maximum RB amount transmittable in each cell group, determined by the cell bandwidth, is M. FIG. 10 assumes that the vRAN comprises three cell groups (1001, 1003, 1005).

[0107] In FIG. 10, the total CRB required by all cell groups is X+Y+Z, and the total bandwidth RB corresponds to 3M. If calculated assuming that cell group 0 (1001) uses M RB, the remaining RB available to cell groups 1 and 2 is (X+Y+Z)-M RB. If calculated assuming that the remaining RB is shared between cell groups 1 and 2, each can be allocated (X+Y+Z) / 2 - M / 2 RB as a resource. In the present disclosure, the (X+Y+Z) / 2 - M / 2 RB can be set as RB commonly used by all cell groups, i.e., interference-concentrated RB.

[0108] In FIG. 10, if the resources allocated to each cell group are arranged in an arbitrary order (e.g., in order of lowest frequency or highest frequency), (X+Y+Z) / 2 - M / 2 RB can be the interference-concentrated RB. The remaining RBs in cell group 0, excluding the interference-concentrated RB, i.e., M - ((X+Y+Z)-M) / 2 RB = (3M - (X+Y+Z)) / 2 RB, can be the interference-free RBs. If the vRAN distributes the interference-free RBs to cell groups 1 (1003) and 2 (1005) in a manner corresponding to each required RB amount, the distribution can be as shown in FIG. 10.

[0109] In FIG. 10, the method for setting interference-free RB and interference-concentrated RB when the required CPRB amounts of cell groups are different (e.g., X ≠ Y ≠ Z) is exemplified by generalizing the formula as follows. The maximum transmittable RB amount in each of N cell groups is M, and the required RB amount of cell group #n is a n For the case where , the amount of interference concentration RB can be defined as follows: (n = 0, 1, ..., N-1)

[0110] Amount of interference concentration RB common to N cell groups: (Formula 1)

[0111] The amount of interference-free RB of cell group #m is the required CPRB of cell group #m, i.e., a m interference-focused RB in Defined as RB minus RB, it can be calculated as shown in the following Equation 2. (m = 0, 1, ... N-1)

[0112] Amount of interference-free RB of the m-th cell group: (Equation 2)

[0113] Condition 1 for the above Equations 1 and 2 to hold is as follows.

[0114] Condition 1: < M

[0115] To reiterate condition 1 above, the interference-concentrated RB common among cell groups must be smaller than the maximum transmittable RB amount M of each cell. If the interference-concentrated RB is greater than or equal to M RB, all transmittable M RBs in each cell group are operated as interference-concentrated RBs because interference-free RBs cannot be operated.

[0116] Condition 2 for the above Equations 1 and 2 to hold is as follows.

[0117] Condition 2: > M

[0118] To reiterate Condition 2 above, the sum of the required CPRBs of each cell must be greater than the maximum transmittable RB amount M of each cell. If the sum of the required CPRBs of each cell is less than or equal to M RB, there is no need to operate interference-concentrated RBs, so the required CPRBs of each cell group are all operated as interference-free RBs. Figure 10 illustrates a method for setting interference-free RBs and interference-concentrated RBs when Condition 2 is satisfied, that is, when the sum of the required CPRBs of each cell is greater than the maximum transmittable RB amount M of each cell.

[0119] When condition 2 above is satisfied, that is, when the sum of the required CPRBs of each cell is greater than the maximum transmittable RB amount M of each cell, the method for determining the start and end indices of the interference-free RB and interference-concentrated RB for each cell group is as follows.

[0120] For cell groups 0 to 2 (1001, 1003, 1005), the start and end positions of the interference concentration RB can be determined identically. For example, the start of the interference concentration RB can be 0 RB, and the end can be (X+Y+Z) / 2-M / 2 RB. The above example regarding the start and end RBs of the interference concentration RB is also applicable in cases such as mapping from PRB to VRB.

[0121] For cell group 0 (1001), the starting position of the interference-free RB may be (X+Y+Z) / 2-M / 2 RB, which is the same as the end point of the interference-concentrated RB. The end position of the interference-free RB of cell group 0 (1001) may be X RB.

[0122] The interference-free area RB of cell group 1 (1003) is RB obtained by subtracting the interference concentration RB from the required CPRB Y, so it can be determined as Y-(X+Y+Z) / 2+M / 2 RB. For cell group 1 (1003), the starting position of the interference-free RB may be X RB. The ending position of the interference-free RB of cell group 1 (1003) will be determined by adding the interference-free RB area to the starting position. That is, the ending position of the interference-free area RB of cell group 1 (1003) may be X+Y-(X+Y+Z) / 2+M / 2 = (X+Y-Z+M) / 2 RB.

[0123] The interference-free area RB of cell group 2 (1005) is RB obtained by subtracting the interference concentration RB from the required CPRB Z, so it can be determined as Z-(X+Y+Z) / 2+M / 2 RB. For cell group 2 (1005), the starting position of the interference-free RB may be (X+Y-Z+M) / 2 RB. The ending position of the interference-free RB of cell group 2 (1005) may be M RB.

[0124] If the starting position value of the interference-free RB is a decimal value, a ceiling operation (e.g., ceiling operation) may be applied to the decimal value. Therefore, in the present disclosure, the combined area of ​​the interference-concentrated RB area and the interference-free RB area is not limited to a specific value (e.g., M), but may be designed to additionally include a margin area (e.g., 3 RB) that assumes a sequential ceiling operation corresponding to the number of starting positions of the interference-free RB (e.g., 3).

[0125] FIG. 11 is a diagram illustrating an interference-free RB setting method in the case where condition 2 above is not satisfied, that is, when the sum of the required CPRBs of each cell is less than or equal to the maximum transmittable RB amount M of each cell.

[0126] When the above condition 2 is not satisfied, X, Y, and Z can be sequentially distributed according to the requirements of each cell without interference-concentrated RBs, and interference-free RBs can be allocated so that they do not interfere with each other.

[0127] The method for determining the start and end indices of the interference-free RB for each cell group is as follows. For cell group 0 (1101), the start position of the interference-free RB may be 0 RB. For cell group 0 (1101), the end position of the interference-free RB may be X RB.

[0128] For cell group 1 (1103), the starting position of the interference-free RB may be X RB. For cell group 1 (1103), the ending position of the interference-free RB may be X+Y RB.

[0129] For cell group 2 (1105), the starting position of the interference-free RB may be X+Y RB. For cell group 2 (1105), the ending position of the interference-free RB may be X+Y+Z.

[0130] Alternatively, the starting position of the interference-free RB of one cell group and the ending position of the interference-free RB of another cell group may be spaced apart with a slight margin. FIG. 12 is a diagram illustrating a method for setting primary interference RB and interference-concentrated RB when the required CPRB amounts of given cell groups are different, according to one embodiment of the present disclosure.

[0131] FIG. 12 assumes a case where the required CPRB amounts (or loads) of given cell groups 0, 1, and 2 are different as X, Y, and Z, respectively. When setting an interference-free RB according to the present disclosure, if condition 2 is satisfied and condition 3 below is also satisfied, a 'first-order interference RB' rather than an interference-free RB may be set. Here, it is assumed that the vRAN consists of three cell groups.

[0132] Condition 3: >2M

[0133] Sum of the required CPRBs for each cell If this is larger than 2M (instead of M), the interference-free RB area, where there is no interference from RBs used by other cell groups, becomes very small, and the operational gain may not be significant. In this case, an RB area can be set where interference from RBs used by other cell groups is limited to only one.

[0134] In the present disclosure, when 'interference-free RB' is defined as an RB that guarantees no interference coming from other coordinated cell groups, 'first-order interference RB' refers to RBs that guarantee only one interference coming from other coordinated cell groups. That is, 'first-order interference RB' refers to RBs that are used for transmission in two of the cell groups and where interference occurs from only one cell group.

[0135] FIG. 12 illustrates a method for setting a first interference RB. The first interference RB can be set similarly to the method for setting an interference-free RB described in FIG. 10.

[0136] In FIG. 12, the total required CPRB in all cell groups (1201, 1203, 1205) corresponds to X+Y+Z, and the total bandwidth RB corresponds to 3M. Since the sum of the required CPRBs for each cell X+Y+Z > 2M according to Condition 3 above, if we assume, for example, that the first cell group (1201) uses M amount of resources, and similarly assume that the second cell group (1203) uses M amount of resources, the size of the resources used by the third cell group (1205) becomes X+Y+Z - 2M. In the present disclosure, the RB of X+Y+Z - 2M can be set as an RB commonly used by all cell groups, that is, an interference-concentrated RB.

[0137] If we sort the resources allocated to cell groups (1201, 1203, 1205) in order of lowest (or highest) frequency for all cell groups, (X+Y+Z) - 2M RB can be the interference-focused RB in all cell groups (1201, 1203, 1205). In cell group 0 (1201) and cell group 1 (1203), the remaining RBs excluding the interference-focused RBs—namely, M - ((X+Y+Z)-2M) RB = 3M - (X+Y+Z)) RB—can be the first-order interference RBs. (Refer to Fig. 12(b))

[0138] If vRAN distributes RBs to satisfy the CPRB requirements of all cell groups, the RBs may be divided as shown in Fig. 12(c).

[0139] The method for setting the first interference RB and interference concentration RB of Fig. 12(c) can be generalized into a formula and exemplified as follows.

[0140] When vRAN establishes N cooperative cell groups, the required CPRB amount or load of the nth cell group is a n Assuming this, the magnitude of the interference concentration RB common to the cell groups can be calculated as in Equation 3. (n = 0, 1, ..., N-1)

[0141] Amount of interference concentration RB of individual cells common to N cell groups: (Equation 3)

[0142] The amount of primary interference RB of cell group #m is the required CPRB of cell group #m, i.e., a m interference-focused RB in Defined as RB minus RB, it can be calculated as shown in the following Equation 4. (m = 0, 1, ..., N-1)

[0143] Amount of 1st interference RB of the m-th cell group: (Equation 4)

[0144] The method for determining the start and end indices of the primary interference RB and interference concentration RB for each cell group is as follows.

[0145] For all cell groups (1201, 1203, 1205), the start position and end position of the interference concentration RB are set to be the same. The start position of the interference concentration RB is the 0th RB, and the end position of the interference concentration RB may be X+Y+Z - 2M RB.

[0146] For cell group 0 (1201), the starting position of the first interference RB may be X+Y+Z - 2M, which is the end position of the interference concentration RB, and the end position of the first interference RB may be X.

[0147] The amount of primary interference RB required for cell group 1 (1203) can be determined by subtracting the interference concentration RB, (X+Y+Z)- 2M, from Y. For cell group 1 (1203), the starting position of the primary interference RB can be determined as a position leading M by the amount of primary interference RB required for cell group 1 (1203). That is, for cell group 1 (1203), the starting position of the primary interference RB can be M- (Y-(X+Y+Z-2M))= X+ZM RB, and for cell group 1 (1203), the ending position of the primary interference RB can be M.

[0148] As shown in FIG. 12(c), for cell group 2 (1205), the primary interference RB region can be divided into two regions. The starting position of the first region of the primary interference RB of cell group 2 (1205) can be determined as (X+Y+Z)-2M, the ending position of the interference concentration RB, and the ending position of the first region can be determined as X+ZM, which corresponds to the starting position of the primary interference RB of cell group 1 (1203). The starting position of the second region of the primary interference RB of cell group 2 (1205) can be determined as X, which is the ending position of the primary interference region of cell group 0 (1201), and the ending position of the second region can be determined as M.

[0149] Figure 13a illustrates how vRAN distributes interference-free RBs according to the requirements of each cell group.

[0150] vRAN can distribute interference-free RBs according to the requirements of each cell group as shown in Fig. 13a. For example, if the required RB amounts of cell groups 0, 1, and 2 are X, Y, and Z, respectively, they can be distributed such that the sum of the interference-free RBs and interference-concentrated RBs for each cell group is X, Y, and Z, respectively.

[0151] Figure 13b illustrates that vRAN distributes interference-free RBs evenly to each cell group.

[0152] vRAN can distribute interference-free RBs evenly as shown in Fig. 13b, regardless of the requirements of each cell group. For example, if the required RB amounts for cell groups 0, 1, and 2 are X, Y, and Z, respectively, they can be distributed such that the sum of the interference-free RBs and the interference-concentrated RBs for each cell group is (X+Y+Z) / 3. Since the method of distributing interference-free RBs evenly to cell groups can guarantee a minimum interference-free RB area for each cell, it can be applied when interference control is more important than providing the required amount for each cell group.

[0153] In the examples of FIGS. 13a and 13b, interference is eliminated by positioning the interference-free RB regions of different cell groups allocated during a single time interval (e.g., slot) at different locations on the frequency axis. FIG. 13c illustrates a method for eliminating interference by positioning the interference-free RB regions of different cell groups at different locations on the time axis.

[0154] Figure 13c illustrates how vRAN distributes interference-free RBs to each cell group using the time division multiplexing (TDM) method.

[0155] vRAN can allocate interference-free RBs in a TDM manner according to the required amount. For example, depending on the interference-free RB configuration method, during a specific time interval (e.g., slot) (e.g., 1310c), one cell group 0 may exclusively receive interference-free RBs by occupying 100% or M of the resources, while the remaining cell groups may only receive interference-intensive RBs during that time interval (e.g., 1310c). For example, if cell group 0 (1311c) exclusively receives interference-free RBs in slot 0 (1310c), then another cell group (e.g., cell group 1 (1312c)) may exclusively receive interference-free RBs in the next slot.

[0156] The group that monopolizes the interference-free RB per slot may vary by the decision of the vRAN coordinator. Alternatively, the cell group that monopolizes the interference-free RB per slot may change according to established rules. Or, the cell group that monopolizes the interference-free RB per slot may be adjusted based on conditions such as the amount of remaining traffic for each cell group.

[0157] Figures 14a, 14b, and 14c illustrate the changes in the interference-free RB operation status of vRAN based on the resource utilization rate within the DU of vRAN.

[0158] In the present disclosure, resource utilization rate is a ratio determined based on the amount of resources required by cell groups serviced by vRAN, and may mean the ratio of the available resources of vRAN to the amount of resources required by said cell groups.

[0159] Figure 14a illustrates the state change diagram when only the On / Off state of the interference-free RB operation is present.

[0160] A coordinator of vRAN may turn on (1401a) or off (1402a) the proposed method based on the resource utilization rate within the DU. For example, the coordinator may not apply the interference-free RB allocation method according to the proposal of the present disclosure if the L1 resource utilization rate within the DU is below a specific first threshold value (1402a). The first threshold value may be determined as a value that satisfies condition 2. That is, the first threshold value may be determined as the resource utilization rate in a state where the required CPRB of cell groups exceeds M.

[0161] Figure 14b illustrates the state change diagram when additional conditions other than the resource utilization rate within the DU of vRAN are considered.

[0162] The vRAN coordinator can turn the proposed technique on (1401b) or off (1402b) based on the resource utilization rate within the DU. Additionally, the vRAN coordinator can turn the interference-free RB operation state on or off over time. For example, the coordinator can turn the interference-free RB operation on (1401b) in even slots (or in even frames) and turn the interference-free RB operation off (1402b) in odd slots (or in odd frames). Alternatively, the coordinator can turn the interference-free RB operation state on (1401b) if edge UEs are dominant within the cell, and turn it off (1402b) otherwise. This is because when interference-free RB is operated, cell edge UEs mainly gain throughput, while cell center UEs may experience some throughput loss. Therefore, the interference control effect can be maximized by varying whether interference-free RB operation is performed over time.

[0163] Figure 14c illustrates the state change diagram when operating in an interference-free RB operation state and a primary interference RB operation state.

[0164] The vRAN coordinator can decide whether to operate in an interference-free RB operating state (1402c) or in a primary interference RB operating state (1403c) based on the resource utilization rate within the DU. For example, the coordinator may decide to operate in an interference-free RB operating state (1402c) if the resource utilization rate within the DU is greater than a first threshold value, and may decide to operate in a primary interference RB operating state (1403c) if the resource utilization rate is greater than a second threshold value. The first threshold value may be determined as a value that satisfies condition 2. That is, the first threshold value may be determined as a resource utilization rate in a state where the required CPRB of cell groups exceeds M. The second threshold value may be determined as a value that satisfies condition 3. That is, the second threshold value may be determined as a resource utilization rate in a state where the required CPRB of cell groups exceeds 2M.

[0165] FIGS. 15a and FIGS. 15b are diagrams illustrating a method of varying the application of the interference-free RB operating mode over time.

[0166] FIG. 15a is a diagram illustrating a pre-defined slot setting without on / off triggering.

[0167] FIG. 15b is a diagram illustrating how a pre-defined slot set is set to RRC and some of it is turned on / off to DCI (downlink control indicator), MAC (medium access control), CE (control element), etc.

[0168] According to the present disclosure, a method of operating interference-concentrated RBs and interference-free RBs separately may result in a relative gain for edge UEs and a relative loss of throughput for center UEs. Therefore, the operation technique according to the present disclosure may be operated so as not to be applied at the time (e.g., slot) when a center UE is scheduled, but to be applied when an edge UE is scheduled.

[0169] For example, vRAN can operate by fixing a pre-defined slot as in FIG. 15a. vRAN can utilize the pre-defined slot setting without on / off triggering of the proposed technique of the present disclosure. Here, the pre-defined slot setting can be pre-configured between vRAN and the terminal via a Radio Resource Control (RRC) message.

[0170] For example, vRAN can be operated using a set of pre-defined slots as shown in FIG. 15b. vRAN can set a pre-defined slot set to a terminal via an RRC message and then turn some of the pre-defined slot sets on / off using a DCI (downlink control indicator) and / or MAC (medium access control) CE (control element), etc.

[0171] When the interference-free RB area operation technique proposed in this disclosure is applied, the interference pattern experienced by the terminal may change. That is, the technique according to this disclosure may affect the terminal's measurements, particularly CSI (channel state information)-RS (reference signal) and CSI (channel state information)-IM (interference measurement). Therefore, the vRAN needs to inform the terminal of the location (location on the frequency axis and / or time axis) where the interference RB area operation technique is operating. Upon receiving information regarding the location where the interference-free RB area operation technique according to this disclosure is operating, it is desirable for the terminal to perform CSI measurements with the IM (interference management or interference mitigation) technique applied for the corresponding time interval (e.g., slot) and / or the corresponding frequency (e.g., RB). To this end, the base station may inform the terminal through RRC signaling (e.g., message) which slot the IM technique according to this disclosure is applied to.

[0172] For example, the base station can specify and notify the slot to which the IM technique is accurately applied via an RRC message using a static method.

[0173] For example, a base station can set patterns defining different subframes to which IM techniques are applied in a semi-dynamic manner through RRC messages in sets of 4, 8, or 16, and specify and indicate one of the patterns using DCI and MAC-CE bits.

[0174] For example, the base station may, using a semi-dynamic method, set some slots as fixed slots and others as flexible slots via RRC messages, and switch some of the flexible slots via MAC-CE to slots to which the proposed technique according to the present disclosure is applied or slots to which the proposed technique is not applied (slots of the conventional method). Additionally, the base station may use DCI to configure the remaining flexible slots among the flexible slots that are not set via MAC-CE.

[0175] For example, the base station may dynamically designate slots to which the proposed technique is applied and slots to which the proposed technique is not applied (conventional method slots) via DCI or MAC CE. When operating on a frame-by-frame basis, 10 bits may be required in DCI or MAC CE to specify ten subframes (i.e., slots). (Assuming a wireless frame structure where one slot corresponds to one subframe)

[0176] For example, an information element (IE) transmitted via an RRC message can be configured as follows.

[0177] IM-SlotConfig ::= SEQUENCE { slotIndex IM-SlotIndex,symbols CHOICE {all-IM-Conv NULL,all-IM-Prop NULL,explicit SEQUENCE { IM-conv-Symbols INTEGER (1..maxNrofSymbols-1)all-IM-prop-Symbols INTEGER (1..maxNrofSymbols-1)}}}

[0178] When a vRAN operates the IM technique proposed in this disclosure, the interference pattern experienced by the terminal changes, and this change in the interference pattern may affect the terminal's measurements, particularly CSI-RS (channel state information reference signal) and CSI-IM (channel state information interference measurement). In particular, there is a possibility that wideband CQI reports may be distorted due to the operation proposed in this disclosure. Furthermore, when a vRAN uses the technique proposed in this disclosure, the interference experienced by the terminal has a different SINR value than when an RB is assigned without interference consideration. That is, the terminal has different SINR values ​​for an interference-concentrated RB and an interference-free RB, respectively.

[0179] Figure 16 is a diagram showing the signal-to-interference and noise ratio (SINR) by interference-free RB and interference-focused RB.

[0180] The base station may set an interference-free RB when certain conditions are met. The said specific conditions refer to cases where the amount of DU (distributed unit) traffic is sufficient to allow for the setting of interference-concentrated RBs and interference-free RBs, or cases where the capacity of the cell requiring a connection with an adjacent cell reaches a pre-agreed level of capacity. There may be two types of interference patterns experienced by the terminal due to the operation of the present disclosure.

[0181] Interfered SINR (SINR_I) is the SINR of the terminal in interference-concentrated RBs, and interference-free SINR (SINR_IF) is the SINR of the terminal in interference-free RBs. In the formula of FIG. 16, S may represent the magnitude of the measured signal, N may represent the magnitude of the noise, and I_n may represent the magnitude of interference from cell group n.

[0182] Accordingly, the terminal may report different CQIs to the base station for different SINRs by considering the effects of the IM technique proposed in the present disclosure. For example, even if the base station is configured to report a wideband CQI rather than a subband CQI to the terminal, the terminal may report different CQIs for the interference-intensive RB area and the interference-free RB area, respectively, when it identifies the application of the IM technique proposed in the present disclosure. Alternatively, the terminal may report a difference in CQI because the PMI (precoding matrix indication) and RI (rank indication) may differ.

[0183] Examples of information required by a terminal to report CQI in consideration of the IM technique proposed in the present disclosure are as follows. The terminal may require frequency and / or temporal location information of interference-free RBs and interference-concentrated RBs. Additionally, the terminal may require resource elements (REs) and RB location information for interference measurement. Additionally, the terminal may require resource REs and RB location information for measuring a desired signal. Additionally, the terminal may require information on whether the base station is executing the IM technique proposed in the present disclosure. One or more of the information required by the terminal may be designed to be indicated in a combined form.

[0184] Examples of messages and IE for setting information required for a terminal to report CQI in consideration of the proposed IM technique of the present disclosure are as shown in Table 2 below.

[0185] For example, in addition to the existing CSI-IM set list, an IE (csi-IM-ResourceSetList-IF-RB SEQUENCE (SIZE (1..maxNrofCSI-IM-ResourceSetsPerConfig)) OF CSI-IM-ResourceSetId) intended for controlling IM can be added to the CSI RS resource set configuration. (This location is recognized as an interference-free RB.)

[0186] CSI-ResourceConfig-IM ::= SEQUENCE { csi-ResourceConfigId CSI-ResourceConfigId, csi-RS-ResourceSetList CHOICE { nzp-CSI-RS-SSB SEQUENCE { nzp-CSI-RS-ResourceSetList SEQUENCE (SIZE (1..maxNrofNZP-CSI-RS-ResourceSetsPerConfig)) OF NZP-CSI-RS-ResourceSetId OPTIONAL, csi-SSB-ResourceSetList SEQUENCE (SIZE (1..maxNrofCSI-SSB-ResourceSetsPerConfig)) OF CSI-SSB-ResourceSetId OPTIONAL }, csi-IM-ResourceSetList SEQUENCE (SIZE (1..maxNrofCSI-IM-ResourceSetsPerConfig)) OF CSI-IM-ResourceSetId csi-IM-ResourceSetList-IF-RB SEQUENCE (SIZE (1..maxNrofCSI-IM-ResourceSetsPerConfig)) OF CSI-IM-ResourceSetId }, bwp-Id BWP-Id, resourceType ENUMERATED { aperiodic, semiPersistent, periodic}, ...

[0187] For example, if an IM resource cell is assigned to the terminal while maintaining the CSI-RS resource set configuration, it can be configured to measure and report a different CQI for the assigned location. An example of an RRC configuration can take the form shown in Table 3 below.

[0188] IF-RB-Common ::= SEQUENCE { genericParameters IM-RBs,pdsch-ConfigCommonSetupRelease {pdsch-ConfigCommon}}IF-RBs ::= SEQUENCE { locationAndBandwidth INTEGER (0..37949),subcarrierSpacingSubcarrierSpacing,}

[0189] The base station may perform the operation of the proposed IM as a method of informing the terminal of the following combination of reference signal (RS) information for CQI measurement.

[0190] For example, a base station can provide the location of CSI-RS / IM and the location of interference-free RBs at the RB scale.

[0191] For example, a base station can provide the location of CSI-RS / IM and the location of interference-free REs in RE (resource element) units. Interference can be prevented by forcing that the interference-free REs not be used by neighboring cells.

[0192] For example, a base station can provide location information of CSI-RS / IM, interference-free RBs, and interference-concentrated RBs in units of RBs.

[0193] For example, a base station may add a separate CSI-RS resource set for interference-free RB application and provide a CSI-RS resource set for interference-free RB application.

[0194] Based on information regarding the locations of interference-focused RBs and interference-free RBs provided by the base station, the terminal can determine at least one of the frequency and temporal location of the interference-free RBs and interference-focused RBs, the resource element (RE) and / or RB location for interference measurement, the resource RE and / or RB location for desire signal measurement, or whether the base station is executing the corresponding operation.

[0195] The terminal can generate an interference-free RB CQI by measuring the CQI through the CSI RS and CSI IM corresponding to the interference-free RB identified in the above process.

[0196] In addition, the terminal can generate an interference-focused RB CQI by measuring the CQI through the CSI RS and CSI IM corresponding to the interference-focused RB identified in the above process.

[0197] In addition, the terminal can report the interference-free RB CQI and interference-intensive RB CQI generated in the above process to the base station.

[0198] For example, a terminal can combine interference-intensive CQI and interference-free CQI into a single CSI-RS report.

[0199] For example, the terminal can report interference-intensive CQI and interference-free CQI, respectively.

[0200] Due to the technique proposed in the present disclosure, when a terminal is assigned an RB from a base station, the terminal may experience different SINRs for interference-focused RBs and interference-free RBs. Additionally, differences in the modulation and coding scheme (MCS) for interference-focused RBs and interference-free RBs may occur. Therefore, the base station may assign different MCSs to the terminal for interference-focused RBs and interference-free RBs, respectively, to enable operation.

[0201] For example, the base station can be configured to use two codewords with two DCIs. In this case, the terminal must be able to expect two PDSCH allocation DCIs.

[0202] The base station may specify that two codewords can be used with a single DCI. For example, the base station may inform the terminal of the MCS difference. In this case, the terminal will be able to interpret the difference in resource allocation patterns based on the MCS difference. For example, assuming that RBs 0 through 12 have been allocated, the terminal can recognize through prior information exchange that RBs 10 through 12 are allocated as IF (interference-free) RBs, and RBs 0 through 9 are IC (interference-concentrated) RBs. By transmitting the MCS and MCS difference fields to the terminal via the DCI, the base station becomes able to identify the MCS to be applied to the IF RBs and IC RBs, respectively.

[0203] As another example, the base station may provide the terminal with two MCSs via DCI. In this case, since the two MCSs assume different codewords, they may be assigned different HARQ (hybrid automatic repeat and request) processing numbers (#).

[0204] The allocation of HARQ processing numbers by the base station may be individually notified to the terminal or operated via separate signaling.

[0205] Thus, the terminal can decode IF (interference-free) RB with a high MCS and decode interfered RB (e.g., interference-intensive RB) with a relatively low MCS.

[0206] Figure 17 is a diagram illustrating the CSI-RS reporting method.

[0207] FIG. 17(a) shows that the UE (1720) can periodically perform CSI-RS reports (1703a, 1705a, 1707a) in a periodic manner. The UE (1720) can continue to perform CSI-RS reports thereafter.

[0208] FIG. 17(b) is an aperioditic method in which the UE (1720) can repeat the report only for a certain period of time after triggering (1702b) the CSI-RS report (1704b).

[0209] FIG. 17(c) shows a semipersistent method in which the UE (1720) can periodically perform reports until the CSI-RS reports (1704c, 1706c) are deactivated after triggering (1702c).

[0210] FIG. 18 is an exemplary diagram of a method for distributing resource blocks in terms of vRAN according to an embodiment of the present disclosure.

[0211] The above vRAN can determine an interference concentrated RB and an interference free RB based on the RB requirements for at least one cell group belonging to the vRAN (1810).

[0212] The above vRAN may include an operation (1820) of assigning the interference-concentrated RB and the interference-free RB to the at least one cell group.

[0213] The interference-concentrated RB may be an RB used for transmission in all of the at least one cell group. The interference-free RB may be an RB not used for transmission in at least some of the at least one cell group.

[0214] The sum of the RB requirements for the at least one cell group may be less than or equal to the maximum RB amount that can be transmitted in the at least one cell group. In this case, the interference-concentrated RB may not be used.

[0215] The sum of the RB requirements for the at least one cell group may exceed the maximum amount of RB that can be transmitted in the at least one cell group. In this case, the interference-free RB may be an RB used for transmission in only one of the at least one cell groups.

[0216] The sum of the RB requirements for the at least one cell group may exceed twice the maximum amount of RB that can be transmitted in the at least one cell group. In this case, the interference-free RB may be an RB used for transmission in only two of the at least one cell groups, i.e., a first-order interference RB.

[0217] FIG. 19 illustrates the structure of a vRAN device according to an embodiment of the present disclosure.

[0218] Referring to FIG. 19, the vRAN (1900) may include at least one of a processor (1901) and a transceiver (1903). The vRAN (1900) may be implemented in dedicated hardware for separate vRAN (1900) functions or may be implemented in a general-purpose server along with other functions. The functions of the vRAN (1900) or the functions of the coordinator within the vRAN (1900) described with reference to FIG. 1 through 18 may be performed by the vRAN (1900) device of FIG. 19.

[0219] According to the operation method of the vRAN (1900) described above, the processor (1901) and transceiver (1903) of the vRAN (1900) may operate. However, the components of the vRAN (1900) are not limited to the examples described above. For example, the vRAN (1900) may include more components or fewer components than the components described above. Furthermore, the processor (1901) and the transceiver (1903) may be implemented in the form of a single chip. Additionally, the processor (1901) may include one or more processors.

[0220] Methods according to the embodiments described in the claims or specification of the present disclosure may be implemented in the form of hardware, software, or a combination of hardware and software.

[0221] When implemented as software, a computer-readable storage medium may be provided for storing one or more programs (software modules). One or more programs stored on the computer-readable storage medium are configured for execution by one or more processors within an electronic device. One or more programs may include instructions that cause the electronic device to execute methods according to the embodiments described in the claims or specification of this disclosure.

[0222] These programs (software modules, software) may be stored in random access memory, non-volatile memory including flash memory, ROM (Read Only Memory), EEPROM (Electrically Erasable Programmable Read Only Memory), magnetic disc storage devices, CD-ROM (Compact Disc-ROM), Digital Versatile Discs (DVDs), or other forms of optical storage devices, magnetic cassettes. Alternatively, they may be stored in memory composed of some or all of these. Additionally, each constituent memory may include multiple units.

[0223] Additionally, the above program may be stored on an attachable storage device that can be accessed via a communication network such as the Internet, Intranet, Local Area Network (LAN), Wide LAN (WLAN), or Storage Area Network (SAN), or a combination thereof. Such a storage device may be connected to a device performing an embodiment of the present disclosure through an external port. Additionally, a separate storage device on a communication network may be connected to a device performing an embodiment of the present disclosure.

[0224] In the specific embodiments of the present disclosure described above, the components included in the disclosure are expressed in a singular or plural form according to the specific embodiments presented. However, the singular or plural expression is selected to suit the situation presented for convenience of explanation, and the present disclosure is not limited to singular or plural components; even if a component is expressed in the plural form, it may be composed of a singular form, and even if a component is expressed in the singular form, it may be composed of a plural form.

[0225] Meanwhile, although specific embodiments have been described in the detailed description of the present disclosure, it is understood that various modifications are possible within the scope of the present disclosure. Therefore, the scope of the present disclosure should not be limited to the described embodiments, but should be defined by the claims set forth below as well as equivalents thereof.

Claims

1. A method for allocating a resource block (RB) to at least one cell group operated by the vRAN (virtualized radio access network), wherein An operation to determine an interference concentrated RB and an interference free RB that are non-overlappingly arranged at different locations on the frequency axis based on the RB requirements for at least one cell group; and The operation of assigning the determined interference-concentrated RB and interference-free RB to the at least one cell group, wherein The interference-focused RB is an RB used for transmission in all of the at least one cell group, and A method characterized in that the interference-free RB is an RB that is not used for transmission in at least some of the at least one cell group.

2. In Paragraph 1, A method characterized in that the sum of the RB requirements for at least one cell group exceeds the maximum RB amount that can be transmitted in at least one cell group.

3. In Paragraph 2, A method characterized in that the interference-free RB is an RB used for transmission in only one of the at least one cell group.

4. In Paragraph 1, A method characterized in that the sum of the RB requirements for at least one cell group exceeds twice the maximum RB amount that can be transmitted in at least one cell group.

5. In Paragraph 4, A method characterized in that the interference-free RB is an RB used for transmission in only two of the at least one cell group.

6. In Paragraph 1, A method characterized in that the amount of interference-concentrated RB is determined based on the sum of the RB requirements for the at least one cell group, the number of the at least one cell group, and the maximum amount of RB that can be transmitted in the at least one cell group.

7. In Paragraph 1, The amount of interference-free RB of the m-th cell group among the above at least one cell group is, A method characterized by being determined based on the RB requirement for the m-th cell group, the sum of the RB requirements for at least one cell group, the number of at least one cell group, and the maximum RB amount that can be transmitted in the at least one cell group.

8. In Paragraph 1, The above interference-free RB is, A method characterized by being evenly distributed among at least one cell group regardless of the difference in at least one RB requirement corresponding to at least one cell group.

9. In Paragraph 1, A method characterized in that the interference-free RB is assigned to only one of the at least one cell group during a first time interval, and is assigned to only one of the at least one cell group during a second time interval following the first time interval.

10. A virtualized radio access network (vRAN) device that allocates a resource block (RB) to at least one cell group, Transmitter / receiver; and It includes at least one processor, The above-mentioned at least one processor is, Based on the RB requirements for at least one cell group operated by the above vRAN, interference concentrated RBs and interference free RBs are determined to be non-overlappingly placed at different locations on the frequency axis, and It is configured to allocate the determined interference-concentrated RB and interference-free RB to the at least one cell group, and The interference-focused RB is an RB used for transmission in all of the at least one cell group, and A device characterized in that the interference-free RB is an RB that is not used for transmission in some of the at least one cell group.

11. In Paragraph 10, A device characterized in that the sum of the RB requirements for at least one cell group exceeds the maximum RB amount that can be transmitted in at least one cell group.

12. In Paragraph 11, A device characterized in that the interference-free RB is an RB used for transmission in only one of the at least one cell group.

13. In Paragraph 10, A device characterized in that the sum of the RB requirements for at least one cell group exceeds twice the maximum RB amount that can be transmitted in at least one cell group.

14. In Paragraph 13, A device characterized in that the interference-free RB is an RB used for transmission in only two of the at least one cell group.

15. A method for configuring user equipment (UE) at a base station within at least one cell group operated by a vRAN (virtualized radio access network), The operation of transmitting to the UE configuration information specifying a time interval for allocating interference concentrated RBs and interference free RBs that are non-overlappingly arranged at different positions on the frequency axis; and The operation includes receiving a CQI (channel quality information) report measured based on the above setting information, The interference-focused RB is an RB used for transmission in all of the at least one cell group, and A method characterized in that the interference-free RB is an RB that is not used for transmission in some of the at least one cell group.

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