Base station, distributed unit, radio unit, and scheduling method

Abstract

To provide a method, a base station apparatus, a distributed unit (DU) and a radio unit (RU) which are able to avoid inter-cell interference, and a scheduling method practiced in each of the base station apparatus and the DU.SOLUTION: A base station schedules traffic (downlink / uplink) in units of groups in each cell, and determines and schedules the allocation order of resources (sub-frames, slots, RBs) in a group to be different for each cell, so that inter-cell scheduling occupancy is distributed.SELECTED DRAWING: Figure 5

Description

[Technical field]

[0001] The present invention relates to a technique for avoiding inter-cell interference.

[0002] This application claims priority to Korean Application No. 10-2023-0075633, filed on June 13, 2023, the entire contents of which are incorporated herein by reference for all purposes. [Background technology]

[0003] 5G has a lean-carrier design, which means that interference has a greater impact on downlink / uplink performance than LTE, in which a cell-specific reference signal (CRS) is always transmitted.

[0004] The main cause of interference is when a downlink signal transmitted by an adjacent cell affects the reception of a downlink signal by a user equipment (UE) located in a serving cell, and when an uplink signal transmitted by a user equipment (UE) located in an adjacent cell affects the UL reception of the serving cell, i.e., inter-cell interference.

[0005] Therefore, research and development of techniques for minimizing inter-cell interference is one of the important issues.

[0006] The existing base station scheduling method allocates resources sequentially from the earliest slot or sub-frame in which downlink or uplink scheduling is possible when data to be transmitted is received from a higher layer or an uplink scheduling request is received from a terminal (UE).

[0007] Although such existing scheduling methods may appear efficient, they are not efficient in terms of inter-cell interference in situations where adjacent cells exist.

[0008] In particular, in a TDD system, when following the existing scheduling method, the scheduling occupancy rate for the first downlink slot (or subframe) or the first uplink slot (or subframe) is higher than that for other slots (or subframes).

[0009] As a result, when following existing scheduling methods, there is a problem that inter-cell interference occurs frequently / largely in the first downlink slot (or subframe) or the first uplink slot (or subframe), where the scheduling occupancy rate is higher than in other slots (or subframes).

[0010] In the present invention, we propose a new technical solution that enables the distribution of scheduling occupancy rates, moving away from the existing scheduling method, which has the characteristic that the scheduling occupancy rate is high at the same position (e.g., the first downlink / uplink slot) between cells. Summary of the Invention [Problem to be solved by the invention]

[0011] The problem to be solved by the present invention is to realize a new technical solution that enables the distribution of scheduling occupancy rates, moving away from the existing scheduling method that has the characteristic that the scheduling occupancy rate is high at the same position (e.g., the first downlink / uplink slot) between cells. [Means for solving the problem]

[0012] A base station device according to one embodiment of the present invention includes: a memory including an instruction; and a processor that executes the instruction to allocate traffic to a cell according to groups of unit resources preset for the cell, and when allocating traffic to the groups, determines an allocation order of unit resources within the group to be different from each other in order to avoid inter-cell interference in the cell.

[0013] A distributed unit (DU) according to one embodiment of the present invention includes: a memory including an instruction; and a processor that executes the instruction to allocate traffic to a cell according to a group of unit resources preset for the cell, and determines an allocation order of unit resources within the group based on inter-cell interference in the cell when allocating traffic to the group.

[0014] Specifically, when allocating traffic for each group, the processor may determine an allocation order of unit resources within a group by using an interference level for each unit resource measured for the cell.

[0015] Specifically, the processor checks the interference level for each unit resource in the group derived based on the interference level for each unit resource measured from an RU (Radio Unit) of the cell, and when allocating traffic to the group, can determine the allocation order of unit resources in the group based on the interference level for each unit resource in the group.

[0016] Specifically, the processor may determine an allocation order in order from unit resources with the lowest interference level to those with the highest interference level based on the interference level of each unit resource in the group.

[0017] Specifically, the unit resource may be a subframe, or each slot in a subframe, or each Resource Block (RB) in a slot.

[0018] According to one embodiment of the present invention, a radio unit (RU) interoperating with a distributed unit (DU) includes: a memory including an instruction; and a processor that executes the instruction to measure an interference level for each unit resource, transmits information related to the measurement to the DU, and enables the DU to determine an allocation order of unit resources within a group by using the transmitted information when allocating traffic for each group. The DU executes the instruction to measure an interference level for each unit resource, transmits information related to the measurement to the DU, and allocates traffic for each group of unit resources pre-defined for the cell of the RU.

[0019] Specifically, the information transmitted by the processor to the DU may be information measuring the interference level per unit resource, or information calculating the interference level per unit resource in the group using the measured interference level per unit resource.

[0020] A scheduling method performed in a base station device according to one embodiment of the present invention includes a step of allocating traffic for each group of unit resources preset for a cell; when allocating traffic for each group, the step may determine an allocation order of unit resources within the group to be different from each other in order to avoid inter-cell interference in the cell.

[0021] To achieve the above object, a scheduling method performed in a distributed unit (DU) according to a fifth aspect of the present invention includes a step of allocating traffic to a group of unit resources preset for a cell; and when allocating traffic to the group, the step determines an allocation order of unit resources within the group based on inter-cell interference in the cell.

[0022] Specifically, in the step of allocating traffic for each group, an allocation order of unit resources within a group may be determined using an interference level for each unit resource measured for the cell. Effect of the Invention

[0023] According to an embodiment of the present invention, a specific technical configuration is realized in which traffic (downlink / uplink) is scheduled on a group basis in each cell, and the allocation order of resources (subframes, slots, RBs) within the group is determined and scheduled differently for each cell.

[0024] As a result, according to the present invention, it is possible to break away from the existing scheduling method, which has the characteristic that the scheduling occupancy rate between cells is high at the same position (e.g., the first downlink / uplink slot), and distribute the scheduling occupancy rate between cells, thereby avoiding inter-cell interference and improving downlink / uplink transmission performance. [Brief description of the drawings]

[0025] [Figure 1] FIG. 1 is an illustrative diagram showing a state of inter-cell interference. [Diagram 2] 1 is a diagram showing the configuration of a DU and a RU according to an embodiment of the present invention. [Diagram 3] 1 is an exemplary diagram showing an example of a configuration for a group of unit resources (e.g., slots) proposed in the present invention. [Figure 4A] 1 is a diagram illustrating an embodiment of scheduling using an interference level for each unit resource (eg, slot) in a group in accordance with the present invention. [Figure 4B] 1 is a diagram illustrating an embodiment of scheduling using an interference level for each unit resource (eg, slot) in a group in accordance with the present invention. [Diagram 5] 1 is a diagram illustrating an example of determining an allocation order using an interference level for each unit resource (e.g., slot) in a group in accordance with the present invention. [Figure 6] FIG. 10 is an illustrative diagram showing an effect of avoiding inter-cell interference obtained by applying the present invention. [Figure 7] 1 is a diagram showing an embodiment in which a unit resource is applied as an RB in the present invention. [Figure 8] 13 is a diagram showing an embodiment in which cell information (eg, PCI) or a third external device is used in the present invention. [Figure 9A] 13 is a diagram showing an embodiment in which cell information (eg, PCI) or a third external device is used in the present invention. [Figure 9B] 13 is a diagram showing an embodiment in which cell information (eg, PCI) or a third external device is used in the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0026] Various embodiments of the present invention will now be described with reference to the accompanying drawings.

[0027] The present invention relates to a technique for avoiding inter-cell interference.

[0028] 5G has a lean-carrier design, which means that interference has a greater impact on downlink / uplink performance than LTE, in which a cell-specific reference signal (CRS) is always transmitted.

[0029] The main cause of interference is when a downlink signal transmitted by an adjacent cell affects the reception of a downlink signal by a user equipment (UE) located in the serving cell, and when an uplink signal transmitted by a user equipment (UE) located in an adjacent cell affects the UL reception of the serving cell, i.e., inter-cell interference.

[0030] FIG. 1 illustrates such an inter-cell interference situation.

[0031] As can be seen from FIG. 1, in the case of downlink, a downlink interference situation may occur in which a DL signal for UE#2 acts as interference to UE#1.

[0032] In the case of the uplink, an uplink interference situation may occur in which the UL signal of UE#1 acts as interference to the reception of the UL signal of UE#2.

[0033] Therefore, research and development of techniques for minimizing such inter-cell interference is an important issue.

[0034] Meanwhile, the base station's scheduling method is a method of allocating resources sequentially from the earliest slot or subframe in which downlink or uplink scheduling is possible when data to be transmitted is received from a higher layer or an uplink scheduling request is received from a terminal (UE).

[0035] Although such existing scheduling methods may appear efficient, they are not efficient in terms of inter-cell interference in situations where adjacent cells exist.

[0036] In particular, in a TDD system, when following the existing scheduling method, the scheduling occupancy rate for the first downlink slot (or subframe) or the first uplink slot (or subframe) is higher than that for other slots (or subframes).

[0037] This is because downlink data cannot be transmitted during uplink transmission, so data transmitted from a higher layer is buffered and then transmitted from the first approaching DL scheduling possible position (i.e., the first downlink slot (or subframe)) (the same applies to UL scheduling).

[0038] As a result, when following existing scheduling methods, there is a problem that inter-cell interference occurs frequently / largely in the first downlink slot (or subframe) or the first uplink slot (or subframe), where the scheduling occupancy rate is higher than in other slots (or subframes).

[0039] In the present invention, we aim to move away from the existing scheduling method, which is characterized by high scheduling occupancy rates at the same position (e.g., the first downlink / uplink slot) between cells, and realize a new technical solution that enables distribution of scheduling occupancy rates.

[0040] More specifically, the aim is to realize a new technical solution (scheduling technique) that enables distribution of scheduling occupancy rates by scheduling traffic (downlink / uplink) on a group basis in each cell and determining and scheduling the allocation order of resources (subframes, slots, RBs) differently within the group for each cell.

[0041] Hereinafter, with reference to FIG. 2, the technical solution proposed in the present invention, that is, the configuration of a distributed unit (DU) and a radio unit (RU) for implementing a new scheduling technique, will be described in detail.

[0042] Prior to a detailed description, the present invention can be applied to existing 4G (LTE), 5G (NR), upcoming 6G, etc., and can be applied to all TDD (Time Division Duplex) and FDD (Frequency Division Duplex) systems, and can be applied to all existing RAN (Radio Access Network) systems and Open RAN (O-RAN) systems.

[0043] The core feature of the present invention is to realize a technique for minimizing inter-cell interference by differently allocating slots (or subframes) and / or RBs for each cell, and to propose an operation of an RU to effectively determine the allocation order.

[0044] In the following description, for convenience of explanation, the features and various embodiments of the present invention will be described based on the 5G (NR) standard.

[0045] FIG. 2 shows the configurations of a distributed unit 10 (hereinafter, referred to as DU 10) and a radio unit 20 (hereinafter, referred to as RU 20) according to an embodiment of the present invention.

[0046] The base station device can be configured to include such a DU 10 and RU 20.

[0047] Therefore, a base station device to which the present invention is applied may include a memory (not shown) including an instruction word, and a processor (corresponding to DU 10 and / or RU 20 in FIG. 2) that executes the instruction word to allocate traffic according to groups of unit resources set for a cell, and when allocating traffic according to the groups, determines the allocation order of unit resources within the groups to be different from each other in order to avoid inter-cell interference in the cells.

[0048] The following describes in detail the configuration of the DU 10 and the RU 20 according to the embodiment of the present invention.

[0049] First, the DU 10 according to the embodiment of the present invention will be described with reference to FIG.

[0050] The DU 10 according to an embodiment of the present invention may include a memory (not shown) including an instruction word, and a processor (hereinafter, described as an allocation order determination unit 11 and a scheduling unit 12) that executes the instruction word to allocate traffic to a group of unit resources preset for a cell, and determines an allocation order of unit resources within the group based on inter-cell interference in the cell when allocating traffic to the group.

[0051] More specifically, the DU 10 can allocate traffic to each cell (e.g., Cell 1, 2, . . . ) of each RU 20 (e.g., RU 1, 2, . . . ) associated with itself according to a group of unit resources preset thereto.

[0052] Here, the unit resource may be a subframe, or each slot in a subframe, or each Resource Block (RB) in a slot.

[0053] That is, the scheduling unit 12 configured in the DU 10 of the present invention can allocate traffic for each cell (e.g., Cell 1, 2, . . . ) linked with the DU 10 by subframe, slot, or RB group.

[0054] However, in the following description, for convenience of explanation, a unit resource will be referred to as a slot, and an embodiment will be described in which traffic is allocated by groups of slots.

[0055] That is, the scheduling unit 12 configured in the DU 10 can allocate DL / UL traffic to each cell (eg, Cell 1, 2, . . . ) linked with the DU 10 in slot group units.

[0056] Therefore, according to the present invention, during traffic transmission for the Nth group, traffic to be transmitted from the N+1th group can be collected and buffered.

[0057] The group of slots proposed in this invention can be structured as follows. FDD system: Grouping according to the number of consecutive slots set in advance (DL / UL can be set separately) TDD system: 1) Group consecutive slots of the same type 2) Grouping according to the number of consecutive slots set in advance (DL / UL can be set separately)

[0058] In this regard, FIG. 3 shows an example of a configuration related to the groups proposed in the present invention.

[0059] Explaining with reference to FIG. 3, in the case of an FDD system, an example is shown in which four consecutive DL slots and three consecutive UL slots are configured as one group (Set#1, #2, #3, . . . ).

[0060] In the case of a TDD system, examples of the above-mentioned methods 1) and 2) for forming groups are shown in the figure.

[0061] The above-mentioned method 1) is a method for bundling / composing consecutive slots of the same type into one group (Set) (Case #1).

[0062] On the other hand, the above-mentioned method 2) is a method of configuring consecutive slots into one group (Set) based on a preset number of consecutive slots like an FDD system (Case #2). Figure 3 shows an example of bundling / configuring 8 DL and 6 UL consecutive slots into a group (Set).

[0063] As can be seen from FIG. 3, TDD systems differ from FDD systems in that DL and UL are intermixed and there may be slot separation within a bundle.

[0064] Therefore, a base station device to which the present invention is applied, in particular, a DU10 in the base station device, can assign / schedule DL / UL traffic for each cell (e.g., Cell1, 2, ...) linked to itself on a group basis as proposed by the present invention.

[0065] Specifically, when the DU 10 allocates / schedules DL or UL traffic of the Nth group, the DU 10 can buffer data to be transmitted from the N+1th group.

[0066] Also, once the DU 10 completes the transmission of the Nth group, it can allocate / schedule the previously buffered data, i.e., the DL or UL traffic of the N+1th group.

[0067] In particular, in the present invention, in the present invention, in the method of allocating / scheduling DL / UL traffic in slot (or subframe, or RB) group units as described above, a method of determining the allocation order of slots (or subframes, or RBs) within a group differently in order to avoid inter-cell interference is proposed.

[0068] To this end, the allocation order determination unit 11 configured in the DU 10 of the present invention performs the function of determining the allocation order of unit resources, i.e., slots (or subframes, or RBs), within a group according to inter-cell interference in a cell when allocating traffic by slot (or subframe, or RB) group as described above.

[0069] In the following description, as in the above embodiment, for convenience of explanation, the unit resource is referred to as a slot, and an embodiment in which the allocation order of slots within a group is determined will be described.

[0070] To explain a specific embodiment, when the allocation order determination unit 11 allocates traffic by group to each cell (e.g., Cell 1, 2, ...) linked to the DU 10, it can determine the allocation order of slots within the group by using the slot-by-slot interference level measured for each cell (e.g., Cell 1, 2, ...).

[0071] Referring to Cell 1 formed by RU 1 (20) among the cells (e.g., Cell 1, 2, ...) shown in FIG. 2, when the allocation order determination unit 11 allocates traffic by group to Cell 1, it can determine the allocation order of slots within the group by using the interference level by slot measured in the corresponding Cell 1.

[0072] More specifically, the allocation order determination unit 11 checks the slot-by-slot interference level within a group derived based on the slot-by-slot interference level measured from an RU (hereinafter, RU1(20)) of a cell (hereinafter, Cell1), and when allocating traffic by group, can determine the allocation order of each slot within the group based on the confirmed slot-by-slot interference level within the group.

[0073] In the following, an embodiment of a method for determining the allocation order of slots within a group will be described.

[0074] In this embodiment, the allocation order of each slot in a group is determined basically using the interference level for each slot measured / transmitted by the RU.

[0075] More specifically, in the first embodiment, an RU (hereinafter, RU1(20)) of the present invention can measure an interference level for each unit resource (eg, slot) and transmit information related to the measurement to the DU10.

[0076] The "information" transmitted to the DU 10 at this time may be information indicating that the RU1 (20) has measured the interference level for each slot.

[0077] That is, for example, RU1 (20) can measure an interference level for each slot in its own Cell1 and transmit such measurement information to DU10 periodically, when detecting a change in the surrounding environment, or at the request of DU10.

[0078] In this case, DU10 can calculate / derive the slot-by-slot interference level within the group by averaging the interference levels for each slot index within the group based on the group configuration information for Cell1 of the corresponding RU1(20) using the slot-by-slot interference level measurement information transmitted from RU1(20).

[0079] Therefore, the DU 10 (allocation order determination unit 11) can sequentially determine the allocation order of slots in the group in order of increasing interference level from the unit resource, i.e., the slot, with the lowest interference level, based on the interference level per slot in the group derived through the above-mentioned average calculation.

[0080] Meanwhile, in a second embodiment of the present invention, an RU (hereinafter, RU1(20)) can measure an interference level for each unit resource (eg, slot) and transmit information related to the measurement to the DU10.

[0081] The "information" transmitted to the DU 10 at this time may be information obtained by RU1 (20) measuring the interference level for each slot and then calculating the average interference level for each slot index in the group related to its own Cell1.

[0082] That is, for example, RU1 (20) may acquire and know group configuration information related to its own Cell1 from DU 10.

[0083] Then, RU1 (20) measures the interference level per slot in its own Cell1, and calculates / derives the interference level per slot in the group by averaging the interference levels per slot index in the group based on the group configuration information related to its own Cell1.

[0084] Next, RU1 (20) can transmit slot-by-slot interference level information for Cell1 derived through measurement and average calculation as described above to DU10 periodically, when detecting a change in the surrounding environment, or at the request of DU10.

[0085] Then, DU10 (allocation order determination unit 11) can sequentially determine the allocation order of slots in the group based on the interference level for each slot in the group transmitted from RU1 (20) in order of increasing interference level from the unit resource, i.e., the slot, with the lowest interference level.

[0086] Therefore, when DU 10 (scheduling unit 12) allocates / schedules DL / UL traffic for Cell 1 on a group basis, it can allocate / schedule the DL / UL traffic in accordance with the allocation order of slots within the group determined by the allocation order determination unit 11.

[0087] Meanwhile, in the above-mentioned second embodiment, more specifically, RU1 (20) may directly determine the allocation order of slots in the group based on the slot-by-slot interference level for Cell1 derived through measurement and average calculation, and may transmit the determined allocation order to DU10 periodically, when detecting a change in the surrounding environment, or at the request of DU10.

[0088] In this case, when DU10 (scheduling unit 12) allocates / schedules DL / UL traffic for Cell1 on a group basis, it can allocate / schedule DL / UL traffic according to the slot allocation order within the group transmitted from RU1 (20).

[0089] Therefore, in the present invention, when DU10 allocates / schedules DL or UL traffic of the Nth group for each cell (e.g., Cell1, 2, ...), it buffers data to be transmitted from the N+1th group, and when the transmission of the Nth group is completed, it can allocate / schedule the previously buffered data, i.e., DL or UL traffic of the N+1th group, according to the slot allocation order within the group determined for the corresponding cell.

[0090] Next, an RU 20 according to an embodiment of the present invention will be described with reference to FIG.

[0091] According to an embodiment of the present invention, the RU 20 may include a memory (not shown) including an instruction word, and a processor (hereinafter described as an interference level measurement unit 21 and an information transmission unit 22) that executes the instruction word to measure an interference level for each unit resource, transmits information related to the measurement to the DU 10, and enables the DU 10 to allocate traffic for each group of unit resources pre-defined for the cell of the RU 20, and determine an allocation order of unit resources within the group using the information when allocating traffic for the group.

[0092] In the following description, for convenience of explanation, a unit resource will be referred to as a slot, and an embodiment will be described in which traffic is allocated by groups of slots.

[0093] The interference level measurement unit 21 can measure an interference level for each slot in a cell of the RU 20 .

[0094] The information transmission unit 22 can transmit information related to the slot-by-slot interference level measured by the interference level measurement unit 21 to the DU 10 periodically, when detecting a change in the surrounding environment, or at the request of the DU 10.

[0095] At this time, like the first embodiment described above, the "information" transmitted to the DU 10 may be information indicating the interference level for each slot measured by the RU 20 (interference level measuring unit 21).

[0096] In the case of this first embodiment, the DU 10 can calculate / derive the slot-by-slot interference level in the group by averaging the interference levels for each slot index in the group based on the group configuration information related to the cell of the corresponding RU 20 using the slot-by-slot interference level measurement information transmitted from the RU 20.

[0097] Therefore, for the cell of RU 20, DU 10 can sequentially determine the allocation order of slots in the group in order from the unit resource, i.e., the slot with the lowest interference level to the slot with the highest interference level, based on the interference level per slot in the group derived through the above-mentioned average calculation.

[0098] Meanwhile, as in the second embodiment described above, the "information" to be transmitted to the DU 10 may be information obtained by the RU 20 measuring the interference level for each slot and then averaging the interference levels for each slot index within a group for its own cell.

[0099] In this second embodiment, the DU 10 can sequentially determine the allocation order of slots in the group for the cell of the RU 20 based on the interference level for each slot in the group transmitted from the RU 20, in order of increasing interference level from the unit resource, i.e., the slot, with the lowest interference level.

[0100] Therefore, in the present invention, when DU10 allocates / schedules DL or UL traffic of the Nth group for each cell (e.g., Cell1, 2, ...), it buffers data to be transmitted from the N+1th group, and when the transmission of the Nth group is completed, it can allocate / schedule the previously buffered data, i.e., DL or UL traffic of the N+1th group, according to the slot allocation order within the group determined for the corresponding cell.

[0101] 4A and 4B are diagrams illustrating an embodiment of scheduling using an interference level for each unit resource (eg, slot) in a group in the present invention.

[0102] Case #1 shown in FIG. 4A is an example in which the DU 10 determines the allocation order of slots within a group, and corresponds to the first example described above.

[0103] Specifically, 1. RU 20 measures the interference level for each slot, and 2. transmits it to DU 10. 3. DU 10 processes (e.g., calculates the average) the transmitted interference level for each slot according to group configuration information for the cell of RU 20, and 4. determines the allocation order of slots within the group.

[0104] Meanwhile, Case #2 shown in FIG. 4B is an embodiment in which the RU 20 determines the slot allocation order within a group, and corresponds to the above-mentioned second embodiment.

[0105] To explain, 1. DU 10 transmits group configuration information to RU 20 in advance, 2. RU 20 measures the interference level for each slot, 3. processes (e.g., averages) the measured interference level for each slot to determine the allocation order of slots within a group, and 4. RU 20 transmits the determined allocation order of slots within a group to DU 10.

[0106] FIG. 5 shows an example of allocation order determination using interference levels for each unit resource (eg, slot) in a group in the present invention.

[0107] That is, in the above first and second embodiments, an example is given of how the slot allocation order is determined depending on the interference level of slots within a group.

[0108] According to the embodiment of FIG. 5, five slots are configured as one group for DL.

[0109] Therefore, as shown in FIG. 5, based on the interference level per slot in the group derived through processing (e.g., average calculation) of the interference level per slot, allocation order 1 can be determined for the slot (index 2) with the lowest interference level, and allocation orders 2, 3, 4, and 5 can be determined for each slot (index 0→1→4→3) in order of increasing interference level.

[0110] A low interference level means that the frequency of data transmission from adjacent cells in the corresponding slot is low. The interference level for each slot is measured / processed / derived differently for each cell (e.g. Cell1, 2, ...).

[0111] In other words, in the present invention, for each cell (e.g., Cell 1, 2, ...), a method is used to schedule data with the highest priority to the slot with the lowest interference level based on the slot-by-slot interference level in the group derived through processing (e.g., average calculation) of the slot-by-slot interference level, thereby making it possible to distribute the scheduling occupancy rate between cells rather than concentrating it in the same position (e.g., the first downlink / uplink slot), thereby reducing the probability of inter-cell interference.

[0112] FIG. 6 is an exemplary diagram showing an effect of avoiding inter-cell interference obtained by applying the present invention.

[0113] Figure 6 shows the existing situation when the proposed technology of the present invention is not applied. As can be seen from this, in Cell1 and Cell2, in the case of DL, data transmitted from the upper layer of the uplink transmission is buffered, and then data is scheduled and transmitted from the first slot position where DL transmission is possible.

[0114] This shows that since the scheduling occupancy rate is high at the same position (e.g., the first DL slot) in both adjacent Cell1 and Cell2, interference will occur at eight DL slots between Cell1 and Cell2 with a high probability.

[0115] On the other hand, FIG. 6 shows a situation where the "proposed technology is applied" of the present invention (for example, four DL slots are configured as one group).

[0116] As can be seen, in Cell1 and Cell2, the interference levels for each slot are measured / processed / derived differently, and therefore the allocation order of slots within the group is also determined differently and used for scheduling.

[0117] Therefore, when the present invention is applied, in the case of DL, in Cell1 and Cell2, as in the conventional case, data transmitted from the upper layer for uplink transmission is buffered, and then data is scheduled and transmitted from the first slot position where DL transmission is possible. However, since the slot allocation order within the group is different for each cell, the scheduling occupancy rate between cells is distributed rather than being concentrated in the same position (e.g., the first DL slot), which reduces the probability of inter-cell interference (8 DL slots → 4 DL slots).

[0118] Furthermore, the present invention can be extended to a technique for determining the allocation order of RBs within each slot, rather than just the allocation order of slots within a group.

[0119] For example, FIG. 7 shows an embodiment in which the present invention can be applied to determine that the allocation order of slots in a group is the same, but the allocation order of RBs within a slot is different.

[0120] As can be seen from Figure 7, by applying this method to determine the allocation order of RBs within a slot, the probability of inter-cell interference can be reduced even when the data to be transmitted is smaller than one slot, thereby effectively eliminating the effects of inter-cell interference.

[0121] As described above, according to the present invention, by implementing a specific technical configuration in which traffic (downlink / uplink) is scheduled on a group basis in each cell and the allocation order of resources (subframes, slots, RBs) within the group is determined and scheduled differently for each cell, the scheduling occupancy rate between cells can be distributed without being concentrated in the same position (e.g., the first downlink / uplink slot).

[0122] As a result, according to the present invention, by breaking away from the existing scheduling method characterized in that the scheduling occupancy rate between cells is high at the same position (e.g., the first downlink / uplink slot), it is possible to distribute the scheduling occupancy rate between cells, thereby achieving the effects of avoiding inter-cell interference and improving downlink / uplink transmission performance.

[0123] Meanwhile, in the above, the interference level for each unit resource (subframe, slot, RB) measured in the corresponding cell is used as a criterion for determining the allocation order of unit resources (subframe, slot, RB) within a group.

[0124] In addition, the present invention can be extended to a method of determining the allocation order of unit resources (subframes, slots, RBs) within a group using various criteria.

[0125] As an example, in the present invention, the allocation order of unit resources (subframes, slots, RBs) within a group can be determined by using cell information (eg, PCI, Physical Cell Identifier).

[0126] As another example, in the present invention, the allocation order of unit resources (subframes, slots, RBs) within a group can also be determined using a third external device such as a RIC (RAN Intelligent Controller) of an O-RAN system.

[0127] First, with reference to FIG. 8, an example of determining the allocation order using cell information (eg, PCI) will be described.

[0128] In the present invention, N different allocation orders are predefined, and an allocation order according to a result value of MOD N operation on the PCI (or cell ID) of a cell can be determined from the defined N allocation orders.

[0129] For example, FIG. 8 shows an embodiment in which an FDD system in which six slots form one group has three different allocation orders predefined.

[0130] In this case, assuming a cell with PCI=103, a MOD N (N=3) operation on PCI=103 results in a value of 1. Therefore, in the present invention, traffic (downlink / uplink) is allocated / scheduled for the cell in group (6 DL / UL slots) units, and when traffic is allocated / scheduled by group, it can be allocated / scheduled according to the allocation order (5, 6, 1, 2, 3, 4) defined for PCI MOD3=1 out of the three allocation orders (PCI MOD3=0, 1, 2).

[0131] As can be seen from Figure 8, the predefined allocation order can be configured to prevent overlapping as much as possible, so that the probability of interference occurring between cells with different PCI MOD values ​​is lower than when the proposed invention is not applied.

[0132] Therefore, in the case of FIG. 8, if the amount of data transmitted from a cell with PCI=103 is within two slots, there should be no interference with the first two slots of an adjacent cell whose result of the MOD N (N=3) calculation is 0 or 2.

[0133] Next, an example of determining the allocation order using a third external device (RIC) will be described with reference to FIG.

[0134] As shown in FIG. 9A, in the present invention, an external device (RIC) can determine the allocation order of unit resources (subframes, slots, RBs) within a group for each cell based on the geographical location information of the cell (Case #1).

[0135] That is, as can be seen from Case #1 in Figure 9, the external device (RIC) knows the location information for each RU / cell of each base station device, and based on this, in the present invention, the external device (RIC) can determine the allocation order for each RU / cell so that the allocation order between adjacent cells does not overlap as much as possible.

[0136] Case #1 in FIG. 9A shows an example in which the order of slot allocation within two types of groups (bundles) is determined based on cell location information.

[0137] For convenience, it is assumed that the cells are located in one dimension, and in the case of Case #1 of FIG. 9A, inter-cell interference can be avoided by crossing / determining and transmitting so that adjacent cells have slot allocation orders within different groups.

[0138] On the other hand, as shown in FIG. 9B, in the present invention, an external device (RIC) can determine the allocation order of unit resources (subframes, slots, RBs) in a group for each cell based on slot-by-slot transmission success rate information collected from each base station device (or DU) (Case #2).

[0139] That is, as can be seen from Case #2 in FIG. 9B, the external device (RIC) can collect slot-specific transmission success rate information from each base station device (or DU), and based on this, can predict inter-cell interference and determine the allocation order of slots within a group for each cell in a direction that reduces the interference.

[0140] Specifically, the external device (RIC) can determine the allocation order of slots in a group for each cell by updating the allocation order of slots in a group already allocated to the corresponding cell based on the collected slot-by-slot transmission success rate information.

[0141] For example, as shown in the table in Case #2 of Figure 9B, in a situation where the transmission success rate of slot index 3 has dropped significantly but the existing / currently highest allocation order 1 has been assigned, the external device (RIC) can re-determine the allocation order of slots within the group by exchanging the allocation orders of slot index 2, which has the highest transmission success rate but is the final allocation order, with slot index 3 using an update method.

[0142] As described above, according to various embodiments of the present invention, by implementing a specific technical configuration in which traffic (downlink / uplink) is scheduled on a group basis in each cell and the allocation order of resources (subframes, slots, RBs) within the group is determined and scheduled differently for each cell, the scheduling occupancy rate between cells can be distributed rather than concentrated in the same position (e.g., the first downlink / uplink slot).

[0143] As a result, according to the present invention, by breaking away from the existing scheduling method that has the characteristic that the scheduling occupancy rate between cells is high at the same position (e.g., the first downlink / uplink slot), and proposing a new scheduling technique that enables the distribution of the scheduling occupancy rate between cells, it is possible to derive the effects of avoiding inter-cell interference and improving downlink / uplink transmission performance.

[0144] The base station device, the distributed unit, the wireless unit, and the scheduling method according to the embodiments of the present invention may be embodied in the form of program instructions executable by various computer means and recorded on a computer-readable medium. The computer-readable medium may include program instructions, data files, data structures, and the like, alone or in combination. The program instructions recorded on the medium may be specially designed and configured for the present invention, or may be known and available to those skilled in the art of computer software. Examples of computer-readable recording media include magnetic media such as hard disks, floppy disks, and magnetic tapes, optical media such as CD-ROMs and DVDs, magneto-optical media such as floptical disks, and hardware devices specially configured to store and execute program instructions, such as ROMs, RAMs, flash memories, and the like. Examples of program instructions include high-level language codes that can be executed by a computer using an interpreter, as well as machine language codes such as those produced by a compiler. The hardware devices may be configured to operate as one or more software modules to perform the operations of the present invention, and vice versa.

[0145] Although the present invention has been described in detail above with reference to preferred embodiments, the present invention is not limited to the above embodiments, and it can be said that the technical concept of the present invention extends to the extent that anyone having ordinary knowledge in the technical field to which the present invention pertains can make various modifications or alterations without departing from the gist of the present invention as claimed in the following claims.

Claims

1. In the base station device, A memory containing an instruction word; and a processor that executes the command to allocate traffic to a cell according to a group of unit resources preset for the cell, and determines an allocation order of unit resources within the group to be different from each other in order to avoid inter-cell interference in the cell when allocating traffic to the group.

2. In the Distributed Unit (DU), A memory containing an instruction word; and A processor that executes the command to allocate traffic to a cell according to a group of unit resources preset for the cell, and determines an allocation order of unit resources within the group according to inter-cell interference in the cell when allocating traffic to the group.

3. The processor is The distributed unit according to claim 2, wherein when allocating traffic to each group, an allocation order of unit resources within a group is determined by using an interference level for each unit resource measured in the cell.

4. The processor is determining an interference level for each unit resource in the group derived based on an interference level for each unit resource measured from a radio unit (RU) of the cell; The distributed unit according to claim 3, wherein when allocating traffic to each group, an allocation order of unit resources within the group is determined based on an interference level for each unit resource within the group.

5. The processor is The distributed unit according to claim 4 , wherein the allocation order is determined in order from the unit resource with the lowest interference level to the unit resource with the highest interference level based on the interference level of each unit resource in the group.

6. The above unit resources are: The distributed unit according to claim 2, characterized in that the distributed unit is a subframe, or each slot in a subframe, or each resource block (RB) in a slot.

7. In a radio unit (RU) in communication with a distributed unit (DU), A memory containing an instruction word; and By executing the command, an interference level for each unit resource is measured, and information related to the measurement is transmitted to the DU. A wireless unit comprising: a processor that enables the DU, which allocates traffic for each group of unit resources preset for the cell of the RU, to determine an allocation order of unit resources within the group using the transmitted information when allocating traffic for each group.

8. The information that the processor communicates to the DU is: Information on the measurement of the interference level for each unit resource, or The wireless unit according to claim 7, wherein the information is obtained by calculating an interference level for each unit resource in the group using the measured interference level for each unit resource.

9. A scheduling method performed by a base station device, Allocating traffic to a group of unit resources preset for a cell; The method according to the above step, wherein when allocating traffic to each of the groups, an allocation order of unit resources within each group is determined to be different from each other in order to avoid inter-cell interference in the cells.

10. A scheduling method performed in a distributed unit (DU), comprising: Allocating traffic to a group of unit resources preset for a cell; The method according to claim 1, wherein the step of allocating traffic by group includes determining an allocation order of unit resources within a group according to inter-cell interference in the cell.

11. The above steps are: The method of claim 10, wherein when allocating traffic to each group, an allocation order of unit resources within a group is determined using an interference level for each unit resource measured in the cell.

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