KR20230157849A - Method and apparatus for controlling inter-cell interference in wireless communication system - Google Patents

Abstract

This disclosure relates to 5G or 6G communication systems to support higher data rates. According to various embodiments disclosed in this document, a method performed by a serving base station in a wireless communication system includes receiving information about an aggregated slot from an aggregated slot management device, the aggregated slot Based on information about, aggregating and scheduling traffic to be transmitted in a certain section into concentrated slots, determining separate AMC (adaptive modulation and coding) for concentrated slots and non-intensive slots, using the determined AMC It may include transmitting traffic in the concentrated slot.
In addition to this, various embodiments identified through the specification are possible.

Description

Method and apparatus for controlling inter-cell interference in a wireless communication system {METHOD AND APPARATUS FOR CONTROLLING INTER-CELL INTERFERENCE IN WIRELESS COMMUNICATION SYSTEM}

This disclosure relates to wireless communication systems, and more particularly to methods and devices for controlling inter-cell interference in wireless communication systems.

5G mobile communication technology defines a wide frequency band to enable fast transmission speeds and new services, and includes sub-6 GHz ('Sub 6GHz') bands such as 3.5 gigahertz (3.5 GHz) as well as millimeter wave (mm) bands such as 28 GHz and 39 GHz. It is also possible to implement it in the ultra-high frequency band ('Above 6GHz') called Wave. In addition, in the case of 6G mobile communication technology, which is called the system of Beyond 5G, Terra is working to achieve a transmission speed that is 50 times faster than 5G mobile communication technology and an ultra-low delay time that is reduced to one-tenth. Implementation in Terahertz (THz) bands (e.g., 3 terahertz bands at 95 GHz) is being considered.

In the early days of 5G mobile communication technology, there were concerns about ultra-wideband services (enhanced Mobile BroadBand, eMBB), ultra-reliable low-latency communications (URLLC), and massive machine-type communications (mMTC). With the goal of satisfying service support and performance requirements, efficient use of ultra-high frequency resources, including beamforming and massive array multiple input/output (Massive MIMO) to alleviate radio wave path loss in ultra-high frequency bands and increase radio transmission distance. Various numerology support (multiple subcarrier interval operation, etc.) and dynamic operation of slot format, initial access technology to support multi-beam transmission and broadband, definition and operation of BWP (Band-Width Part), large capacity New channel coding methods such as LDPC (Low Density Parity Check) codes for data transmission and Polar Code for highly reliable transmission of control information, L2 pre-processing, and dedicated services specialized for specific services. Standardization of network slicing, etc., which provides networks, has been carried out.

The development of the 5G mobile communication system includes new waveforms, full dimensional MIMO (FD-MIMO), array antennas, and large-scale antennas to ensure coverage in the terahertz band of 6G mobile communication technology. Multi-antenna transmission technology such as (Large Scale Antenna), metamaterial-based lenses and antennas to improve coverage of terahertz band signals, high-dimensional spatial multiplexing technology using OAM (Orbital Angular Momentum), and RIS (Reconfigurable Intelligent Surface) ) technology, as well as full duplex technology, satellite, and AI (artificial intelligence) to improve the frequency efficiency of 6G mobile communication technology and system network, from the design stage and end-to-end. End) It is based on the development of AI-based communication technology that realizes system optimization by internalizing AI support functions, and next-generation distributed computing technology that realizes services of complexity beyond the limits of terminal computing capabilities by utilizing ultra-high-performance communication and computing resources. It could be.

In communication/broadcasting systems, link performance can be significantly degraded by various channel noises, fading phenomena, and inter-symbol interference (ISI). Therefore, in order to implement high-speed digital communication/broadcasting systems that require high data throughput and reliability, such as next-generation mobile communication, digital broadcasting, and portable Internet, it is necessary to develop technology to overcome noise, fading, and inter-symbol interference.

Various embodiments of the present disclosure provide a method and apparatus performed by a serving cell for controlling inter-cell interference in a wireless communication system.

According to various embodiments of the present disclosure, a method performed by a serving base station in a wireless communication system includes receiving information about an aggregated slot from an aggregated slot management device, A step of aggregating and scheduling traffic to be transmitted in a certain section to a concentrated slot based on information, a step of determining separate AMC (adaptive modulation and coding) for the concentrated slot and a non-intensive slot, and using the determined AMC to select a concentrated slot It may include transmitting traffic to the terminal.

According to various embodiments of the present disclosure, a serving base station device in a wireless communication system includes a transceiver and at least one processor, and the at least one processor includes a centralized slot management device. It receives information about aggregated slots from the aggregated slot, and based on the information about the aggregated slot, traffic to be transmitted in a certain period is aggregated and scheduled in the aggregated slot, and separate AMC (AMC) is installed in the aggregated slot and the non-aggregated slot. adaptive modulation and coding) may be determined, and traffic in the concentrated slot may be transmitted to the terminal using the determined AMC.

According to various embodiments of the present disclosure, a method performed by a neighboring base station in a wireless communication system includes receiving information about an aggregated slot from an aggregated slot management device, It may include the step of aggregating and scheduling traffic to be transmitted in a certain period into a concentrated slot based on information about the traffic, and transmitting the traffic to the terminal in the concentrated slot.

According to various embodiments of the present disclosure, a device of a neighboring base station in a wireless communication system includes a transceiver and at least one processor, wherein the at least one processor operates in a concentration slot. Receives information about an aggregated slot from a management device, aggregates and schedules traffic to be transmitted in a certain period to an aggregated slot based on the information about the aggregated slot, and transfers the traffic from the aggregated slot to a terminal. You can set it to transmit.

1 illustrates an example of a radio resource area in a wireless communication system according to various embodiments of the present disclosure.
Figure 2 illustrates an example of radio resource allocation when a concentrated slot is set according to various embodiments of the present disclosure.
Figure 3 shows an example of radio resource allocation when a concentrated slot is set according to various embodiments of the present disclosure.
Figure 4 illustrates an example of radio resource allocation when a concentrated slot is set according to various embodiments of the present disclosure.
Figure 5 illustrates an example of radio resource allocation when a concentrated slot is set according to various embodiments of the present disclosure.
Figure 6 illustrates the buffer occupancy (BO) state of a base station when a concentrated slot is set according to various embodiments of the present disclosure.
Figure 7 shows a block diagram of resource allocation according to various embodiments of the present disclosure.
Figure 8 shows an example of the number of code-blocks (CB) and RB per CB according to modulation coding scheduling (MCS) level according to various embodiments of the present disclosure.
FIG. 9 illustrates a flow chart of operations for inter-cell interference control between a centralized slot management device and cells according to various embodiments of the present disclosure.
Figure 10 illustrates the operation of a serving base station according to various embodiments of the present disclosure.
Figure 11 illustrates the operation of an interfering base station according to various embodiments of the present disclosure.
FIG. 12 illustrates a graph of slot usage rate versus cycle time of intensive slots according to various embodiments of the present disclosure.
FIG. 13 illustrates a graph of slot utilization versus the period of concentrated slots according to various embodiments of the present disclosure.
Figure 14 shows a graph of data throughput versus signal to noise ratio (SNR) according to various embodiments of the present disclosure.
Figure 15 shows the structure of a base station in a wireless communication system according to various embodiments of the present disclosure.
In relation to the description of the drawings, identical or similar reference numerals may be used for identical or similar components.

청구되는 대상의 다양한 양상들이 도면들을 참조하여 설명되며, 상기 도면들에서 유사한 도면 부호들은 유사한 엘리먼트들을 지칭하도록 사용된다. 하기의 설명에서, 설명의 목적으로, 다수의 특정 세부사항들이 하나 이상의 실시예들의 충분한 이해를 제공하기 위해 설명된다. 그러나, 상기 실시예(들)은 이들 특정 세부사항들 없이 실행될 수 있음이 명백할 수 있다.

Various aspects of claimed subject matter are described with reference to the drawings, in which like reference numerals are used to refer to like elements. In the following description, for purposes of explanation, numerous specific details are set forth to provide a thorough understanding of one or more embodiments. However, it may be clear that the embodiment(s) may be practiced without these specific details.

Terms used in the present disclosure are merely used to describe specific embodiments and may not be intended to limit the scope of other embodiments. Singular expressions may include plural expressions, unless the context clearly indicates otherwise. Terms used herein, including technical or scientific terms, may have the same meaning as generally understood by a person of ordinary skill in the technical field described in this disclosure. Among the terms used in this disclosure, terms defined in general dictionaries may be interpreted to have the same or similar meaning as the meaning they have in the context of related technology, and unless clearly defined in this disclosure, have an ideal or excessively formal meaning. It is not interpreted as In some cases, even terms defined in the present disclosure cannot be interpreted to exclude embodiments of the present disclosure.

Terms referring to signals used in the following description (e.g. message, signal, signaling, sequence, stream), terms referring to resources (e.g. symbol, slot) , subframe, radio frame, subcarrier, RE (resource element), RB (resource block), BWP (bandwidth part), opportunity (Occasion), for operation Terms referring to data (e.g. step, method, process, procedure), terms referring to data (e.g. information, parameter, variable, value ( value, bit, symbol, codeword), terms referring to channels, terms referring to control information (e.g. downlink control information (DCI), medium access control code word (MAC CE) Element), RRC (radio resource control (RRC) signaling), terms referring to network entities, terms referring to device components, etc. are exemplified for convenience of explanation. Accordingly, the present disclosure is not limited to the terms described below, and other terms having equivalent technical meaning may be used.

Various embodiments are described herein with respect to a wireless terminal and/or base station. A wireless terminal may refer to a device that provides voice and/or data connectivity to a user. The wireless terminal may be connected to a computing device, such as a laptop computer or desktop computer, or may be a self-contained device such as a personal digital assistant (PDA). A wireless terminal may also be referred to as a system, subscriber unit, subscriber station, mobile station, mobile, mobile device, remote station, remote terminal, access terminal, user terminal, terminal, wireless communication device, user agent, user device, or user equipment. there is. A wireless terminal is a subscriber station, wireless device, cellular telephone, PCS telephone, cordless telephone, Session Initiation Protocol (SIP) telephone, wireless local loop (WLL) station, personal digital assistant (PDA), portable device with wireless connectivity capability, or It could be any other processing device connected to the wireless modem. A base station (eg, access point) may refer to a device in an access network that communicates with wireless terminals over one or more sectors over a wireless interface. A base station may comprise an Internet Protocol (IP) network and act as a router between wireless terminals and the rest of the access network by converting received air interface frames into IP packets. The base station also coordinates management of attributes for the air interface.

Terms used in the present disclosure are merely used to describe specific embodiments and may not be intended to limit the scope of other embodiments. Singular expressions may include plural expressions, unless the context clearly indicates otherwise. All terms used herein, including technical or scientific terms, may have the same meaning as commonly understood by a person of ordinary skill in the technical field of the present disclosure. Terms defined in commonly used dictionaries can be interpreted as having the same or similar meaning as the meaning they have in the context of related technology, and unless clearly defined in the present disclosure, are not interpreted in an ideal or excessively formal sense. . In some cases, even terms defined in the present disclosure cannot be interpreted to exclude embodiments of the present disclosure.

When two base stations are placed adjacent to each other and a portion of the coverage of the two base stations overlaps, a strong downlink (DL) signal from one base station may cause interference to a terminal served by one base station. That is, inter-cell interference (ICI) may occur between a serving cell formed by base stations and an interfering cell adjacent to the serving cell that causes interference.

Unlike the LTE system, the NR system is designed based on the Ultra-Lean principle to minimize always-on transmission, so it may not interfere with adjacent cells if there is no actual data to transmit. Therefore, ICI control in the 5G NR system is attracting attention as one of the representative technologies for improving network performance.

1 illustrates an example of a radio resource area in a wireless communication system according to various embodiments of the present disclosure.

In various embodiments of the present disclosure, the radio resource area may include a time-frequency area structure. According to one embodiment, the wireless communication system may include a NR communication system.

Referring to Figure 1, in the radio resource area, the horizontal axis represents the time domain and the vertical axis represents the frequency domain. The length of the wireless frame 104 is 10 ms. The radio frame 104 may be a time domain section consisting of 10 subframes. The length of the subframe 203 is 1 ms. The unit in the time domain may be orthogonal frequency division multiplexing (OFDM) and/or discrete fourier transform (DFT)-spread-OFDM (DFT-s-OFDM) symbols, and may be Nsymb OFDM and/or DFT-s-OFDM symbols. Symbols 101 may be gathered together to form one slot 102. In various embodiments, the OFDM symbol may include a symbol for transmitting and receiving signals using an OFDM multiplexing method, and the DFT-s-OFDM symbol may include DFT-s-OFDM or single carrier frequency division (SC-FDMA) Multiple access) May include symbols for transmitting and receiving signals using a multiplexing method. The minimum transmission unit in the frequency domain is a subcarrier, and the carrier bandwidth constituting the resource grid may be composed of a total of NscBW subcarriers 105. In addition, in this disclosure, embodiments related to downlink signal transmission and reception are described for convenience of explanation, but this is also applicable to embodiments related to uplink signal transmission and reception.

In some embodiments, the number of slots 102 constituting one subframe 103 and the length of the slots 102 may vary depending on the subcarrier spacing. This subcarrier spacing is called numerology ( ) can be referred to as. That is, the subcarrier spacing, the number of slots included in the subframe, the length of the slot, and the length of the subframe can be variably configured. For example, in an NR communication system, when the subcarrier spacing (SCS) is 15 kHz, one slot 102 constitutes one subframe 103, and the slot 102 and the subframe 103 The length of may be 1 ms each. Additionally, for example, when the subcarrier spacing is 30 kHz, two slots may constitute one subframe 103. At this time, the length of the slot is 0.5ms and the length of the subframe is 1ms.

In some embodiments, the subcarrier spacing, the number of slots included in the subframe, the length of the slot, and the length of the subframe may be variably applied depending on the communication system. For example, in the case of an LTE system, the subcarrier interval is 15 kHz, and two slots constitute one subframe. In this case, the length of the slot may be 0.5 ms and the length of the subframe may be 1 ms. As another example, for NR systems, the subcarrier spacing ( ) can be one of 15kHz, 30kHz, 60kHz, 120kHz, 240kHz, and the subcarrier spacing ( ), the number of slots included in one subframe may be 1, 2, 4, 8, or 16.

In the time-frequency domain, the basic unit of resources may be a resource element (RE) 106, and the resource element 106 may be expressed as an OFDM symbol index and a subcarrier index. A resource block may include multiple resource elements. In the NR system, a resource block (RB) (or physical resource block (PRB)) 107 is located in the frequency domain. It can be defined as consecutive subcarriers. Number of subcarriers =12. The frequency domain may include common resource blocks (CRBs). A physical resource block (PRB) may be defined in the bandwidth part (BWP) in the frequency domain. CRB and PRB numbers may be determined differently depending on the subcarrier spacing. In the LTE system, RB is in the time domain. in the frequency domain with consecutive OFDM symbols. It can be defined as consecutive subcarriers.

In NR and/or LTE systems, scheduling information for downlink data or uplink data may be transmitted from the base station to the terminal through downlink control information (DCI). In various embodiments, DCI may be defined according to various formats, and each format determines whether the DCI includes scheduling information for uplink data (e.g., UL grant) and scheduling information for downlink data (DL resource allocation). ), compact DCI with a small size of control information, fall-back DCI, spatial multiplexing using multiple antennas, and/or DCI for power control. For example, NR DCI format 1_0 or NR DCI format 1_1 may include scheduling for downlink data. Additionally, for example, NR DCI format 0_0 or NR DCI format 0_1 may include scheduling for uplink data.

As described above, Figure 1 shows an example of a downlink and uplink slot structure in a wireless communication system. In particular, Figure 1 shows the structure of the resource grid of the 3GPP NR system. Referring to FIG. 1, a slot may include a plurality of orthogonal frequency division multiplexing (OFDM) symbols in the time domain and a plurality of resource blocks (RBs) in the frequency domain. A signal may consist of part or all of a resource grid. Additionally, generally, the number of OFDM symbols included in one slot may vary depending on the length of the CP (cyclic prefix). In FIG. 1, for convenience of explanation, an example is shown where one slot consists of 14 OFDM symbols. However, in the case of signals referred to in this disclosure, the configuration of symbols is not specified. In addition, the modulation method of the generated signal is not limited to a specific value of QAM (Quadrature Amplitude Modulation), and can follow the modulation method of various communication standards such as BPSK (Binary phase-shift keying) and QPSK (Quadrature Phase Shift Keying). there is.

Various embodiments of the present disclosure are described based on an LTE communication system or an NR communication system, but the content of the present disclosure is not limited thereto and can be applied to various wireless communication systems for transmitting downlink or uplink control information. In addition, of course, the contents of this disclosure can be applied to unlicensed bands as well as licensed bands, as needed.

Hereinafter, in the present disclosure, higher layer signaling or higher signal is transmitted from the base station to the user terminal using the downlink data channel of the physical layer, or from the user terminal to the base station using the uplink data channel of the physical layer. It may be a signal transmission method. According to one embodiment, the upper layer signaling is radio resource control (RRC) signaling, or signaling along the F1 interface between a centralized unit (CU) and a distributed unit (DU), or a media access control (MAC) control element (MAC). It may include at least one of the signal transmission methods transmitted through a control element (MAC CE). Additionally, according to one embodiment, higher layer signaling or higher signal may include system information commonly transmitted to a plurality of user terminals, for example, a system information block (SIB).

In the 5G wireless communication system, a synchronization signal block (SSB) (or referred to as SS Block, SS/PBCH block, etc.) may be transmitted for initial access, and the synchronization signal block may be referred to as primary synchronization (PSS) signal), SSS (secondary synchronization, signal), and PBCH (physical broadcast channel). In the initial access stage when the user terminal first accesses the system, the user terminal obtains downlink time and frequency domain synchronization from a synchronization signal through a cell search procedure and uses a cell ID (cell ID). ID) can be obtained. Synchronization signals may include PSS and SSS. The user terminal can receive a PBCH including a master information block (MIB) from the base station and obtain system information and basic parameter values related to transmission and reception, such as system bandwidth or related control information. The user terminal may obtain a system information block (SIB) by performing decoding on a physical downlink control channel (PDCCH) and a physical downlink shared channel (PDSCH) based on the received PBCH. Afterwards, the user terminal exchanges its identity with the base station through a random access step and can initially access the network through steps such as registration and authentication.

As described above, one slot can include 14 symbols, and in a 5G communication system, uplink-downlink configuration of symbols and/or slots can be set in three steps.

In the first method, uplink-downlink of a symbol and/or slot can be set semi-statically through cell-specific configuration information through system information in a symbol unit. More specifically, cell-specific uplink-downlink configuration information through system information may include uplink-downlink pattern information and standard subcarrier information. Uplink-downlink pattern information includes the pattern period, the number of consecutive downlink slots from the starting point of each pattern, the number of symbols in the next slot, the number of consecutive uplink slots from the end of the pattern, and the symbol of the next slot. The number can be indicated. Slots and symbols that are not indicated as uplink or downlink may be determined as flexible slots/symbols.

In the second method, through user-specific setting information through dedicated upper layer signaling, a flexible slot or a slot containing flexible symbols is configured to determine the number of consecutive downlink symbols and slots from the start symbol of each slot. It can be indicated as the number of consecutive uplink symbols from the end of , or it can be indicated as the entire downlink of the slot or the uplink of the entire slot.

As a third method, in order to dynamically change the downlink signal transmission and uplink signal transmission sections, symbols indicated as flexible symbols in each slot (e.g., symbols not indicated as downlink and uplink) ) may indicate whether each is a downlink symbol, an uplink symbol, or a flexible symbol through a slot format indicator (SFI) included in the downlink control channel. The slot format indicator can select one index from a table in which the uplink-downlink configuration of 14 symbols in one slot is preset (e.g., 3GPP TS 38.213 Table 11.1.1-1).

Figure 2 illustrates an example of radio resource allocation when a concentrated slot is set according to various embodiments of the present disclosure.

Referring to Figure 2, the horizontal axis represents the time domain and the vertical axis represents the frequency domain. The division unit in the time domain is a slot, and the division unit in the frequency domain may be a subcarrier.

Among the radio resources allocated in the serving cell, there are radio resources that receive interference from traffic in adjacent cells. Traffic receiving interference from an adjacent cell (i.e., traffic from an adjacent cell acting as interference to the serving cell) may be distributed and exist across multiple slots. Referring to FIG. 2, in the conventional case (210), radio resources receiving interference from traffic of adjacent cells may be distributed over a total of 7 slots based on the time axis.

According to an embodiment according to the present disclosure, in order to control inter-cell interference, it is possible to set a specific slot in the time domain to collect and allocate traffic from adjacent cells. A specific slot in the time domain may be referred to as an aggregated slot or an interference aggregated slot. By setting a concentrated slot, traffic transmitted in a certain section can be aggregated and assigned to the concentrated slot.

The centralized slot management device can set the centralized slot in advance and transmit information about the centralized slot to all cells. Accordingly, the positions of the centralized slots of the cells managed by the centralized slot management device may be aligned identically. Specifically, the intensive slot for each cell may include the same operation period and offset settings.

According to an embodiment according to the present disclosure, radio resources allocated to cell traffic may be gathered and scheduled in a preset centralized slot. Referring to FIG. 2, when a concentrated slot is set (220), radio resources allocated to cell traffic may be distributed over a total of two slots (201, 202) based on the time axis. In this case, the frequency of slots to which nothing is assigned, that is, slots to which no traffic is assigned, may increase.

According to an embodiment according to the present disclosure, when setting a concentrated slot, a slot acting as interference may form a larger RB than before. However, in the NR system, even if decoding of only one CB (code-block) fails, the entire TB (transport block) containing the CB can be treated as a transmission failure, so the size of the RB has little effect on the throughput of data transmission. You can. Therefore, even if the size of the RB acting as interference increases by setting a concentrated slot, the negative impact on the throughput of data transmission is small. Rather, the number of slots acting as interference decreases, which improves data transmission performance as the total amount of interference is reduced. You can get the effect.

According to an embodiment according to the present disclosure, when a concentrated slot is set, the inter-cell interference probability of an adjacent cell in the concentrated slot increases, but the inter-cell interference probability of an adjacent cell in other slots (hereinafter, non-intensive slots) increases. Because it is lowered, it is possible to distinguish between time zones where the probability of occurrence of inter-cell interference is high and time zones where the probability of occurrence of inter-cell interference is low.

Figure 3 shows an example of radio resource allocation when a concentrated slot is set according to various embodiments of the present disclosure.

Referring to FIG. 3, the horizontal axis of the graph represents the time domain and the vertical axis represents the frequency domain. The division unit in the time domain is a slot, and the division unit in the frequency domain may be a subcarrier.

According to an embodiment according to the present disclosure, the centralized slot management device can aggregate cell traffic and configure it to be assigned to a specific slot in the time domain. At this time, a specific slot in the time domain may be referred to as an aggregated slot. Cells managed by the concentrated slot management device can collect and allocate cell traffic to the concentrated slot based on information about the concentrated slot. The operation of setting a concentrated slot to control inter-cell interference in the time domain of such a concentrated slot management device may be referred to as TDIA (time domain interference slot alignment).

Information about the concentrated slot can be transmitted to all cells by setting it in advance in the centralized slot management device. Accordingly, the positions of the centralized slots of the cells managed by the centralized slot management device may be aligned identically. Specifically, the centralized slot for each cell may include the same operation period and offset settings.

Referring to FIG. 3, when a concentrated slot is not set, randomly distributed traffic from an adjacent cell adjacent to the serving cell and causing inter-cell interference may affect the serving cell. A serving cell may be affected by interference depending on the slot in which traffic within an adjacent cell is distributed. On the other hand, when a concentrated slot is set, the cell's traffic can be aggregated and allocated in the cell's concentrated slot. When traffic from adjacent cells that acts as interference to the concentrated slot is collected and allocated, the section of the non-concentrated slot to which traffic that acts as interference to the cell is allocated may be long. A non-concentrated slot refers to a slot other than the configured concentrated slot, and may be a slot with a low probability of inter-cell interference occurring.

In other words, when TDIA is operating, the serving cell can transmit more slots with traffic that does not cause interference to the terminal than when TDIA is not operating. Accordingly, the serving cell can transmit more slots with traffic that does not cause interference to the terminal. You can achieve the effect of feeling less affected.

According to an embodiment according to the present disclosure, when a concentrated slot is set, the inter-cell interference probability of an adjacent cell in the concentrated slot increases, but the inter-cell interference probability of an adjacent cell in other slots (hereinafter, non-intensive slots) increases. It can be lowered. On the other hand, if a concentrated slot is not set, the probability of occurrence of inter-cell interference in adjacent cells may occur randomly for each slot.

Figure 4 illustrates an example of radio resource allocation when a concentrated slot is set according to various embodiments of the present disclosure.

According to an embodiment of the present disclosure, when a concentrated slot is set, a cell can schedule traffic to be transmitted in a certain section to the set concentrated slot. More specifically, when traffic occurs, the cell can wait without transmitting traffic until it reaches the set concentration slot. Since this traffic may act as interference to adjacent cells, it can be collected and assigned to a concentrated slot and transmitted to the terminal. That is, traffic may not be transmitted to the terminal due to delayed transmission until it reaches the concentrated slot.

Additionally, if traffic can no longer be assigned to the focused slot, traffic can be assigned to the next slot of the focused slot. At this time, the slot next to the intensive slot may be a non-intensive slot.

Referring to FIG. 4, when traffic is transmitted without a concentrated slot set, the cell's traffic is transmitted to terminals 1 to 3, and the number of concentrated slots to which the cell's traffic is assigned is 12 (401 to 403, 406, 407, 409, 410, 413, 414, and 416 to 418). On the other hand, when a concentrated slot is set and traffic is collected and transmitted in the concentrated slot, the number of concentrated slots is 7 (404, 405, 408, 411, 412, 415, 419), compared to the number in the case where the concentrated slot is not set. It may be less than the number of concentration slots.

According to an embodiment of the present disclosure, when there is a heavy traffic terminal in the serving cell and a light traffic terminal in the interfering cell, traffic may be collected and allocated to a concentrated slot for both the serving cell and the interfering cell. At this time, traffic exceeding the traffic allocated to the concentrated slot of the interfering cell of the serving cell may be less affected by inter-cell interference due to traffic of the interfering cell. For example, referring to FIG. 4, if there is UE 3 in the serving cell and UE 1 or UE 2 in the interfering cell, traffic may be collected in the concentration slots 404 and 405 in both the serving cell and the interfering cell. At this time, if UE 3 exceeds the traffic allocated to the concentrated slot 404 of UE 1 or UE 2, the traffic of UE 3 in the allocated slot 405 may not be affected by interference. Because of this, UE 3 located in the serving cell can obtain performance gains equal to the traffic in the slot 405 that is not affected by interference.

Referring to FIG. 4, when traffic is transmitted without a concentrated slot set, the probability of inter-cell interference relative to the slot exists randomly for each slot, but when traffic is collected and transmitted in a concentrated slot, the probability of occurrence of inter-cell interference relative to the slot is random. Since the probability of occurrence of inter-cell interference in adjacent cells is high and the probability of inter-cell interference in adjacent cells in non-concentrated slots is low, it is possible to distinguish between time zones where the probability of occurrence of inter-cell interference is high and time zones where the probability of occurrence of inter-cell interference is low. Additionally, even if the interference is larger in RB size, it may not have a significant impact on the decoding performance of CB. In other words, even if the size of the RB acting as interference increases by setting a concentrated slot, the negative impact on the throughput of data transmission is small. Rather, the number of slots acting as interference decreases, which improves data transmission performance as the total amount of interference is reduced. You can get the effect.

According to an embodiment according to the present disclosure, since the probability of inter-cell interference occurring in a concentrated slot is high, separate adaptive modulation and coding (AMC) can be determined for each of the concentrated slot and slots other than the concentrated slot (hereinafter, non-focused slots). there is.

The maximum expected value for downlink data throughput from a cell to a terminal is given in Equation 1 below.

and means the data transmission probability in the case where there is no inter-cell interference, and May refer to a TBS to which AMC decision is applied in the case where there is no inter-cell interference. may mean the probability of occurrence of inter-cell interference. means the target probability of successful transmission, The target may be BLER (block error rate).

Generally, in a wireless communication system, it may be difficult to know whether inter-cell interference exists in each time zone. Therefore, the same AMC decisions apply regardless of whether inter-cell interference exists. At this time, <Equation 1> can be summarized as the following <Equation 2>.

silver It can mean the value expressed by replacing , Is can represent. To determine the maximum data throughput, the probability of successful transmission Information may be needed. However, due to inter-cell interference and mobility of radio resources, Information about can be difficult to determine. Therefore, the probability of occurrence of inter-cell interference By reducing , the maximum data throughput can be determined.

According to an embodiment according to the present disclosure, if separate AMC decisions are applied to concentrated slots and non-focused slots that collect and allocate traffic from adjacent cells that act as interference, the probability of occurrence of inter-cell interference can be indirectly reduced.

The base station can increase the SINR (signal to interference noise ratio) of the concentrated slot if the past transmission in the concentrated slot was ACK, and lower it if it was NACK. If the past transmission in the non-concentrated slot was ACK, the SINR of the non-concentrated slot can be increased, and if it is NACK, it can be lowered. SINR can be increased by increasing the strength of the uplink received signal.

The adaptive modulation and coding selection (MCS) level is selected according to the signal SINR ratio of the channel through which data is transmitted and received. A low MCS level is applied to concentrated slots, and a high MCS level is applied to non-intensive slots, so that a low data transmission rate can be applied to concentrated slots where the frequency of occurrence of inter-cell interference is expected to be high.

The detailed operation of setting up these concentrated slots to collect and allocate traffic from neighboring cells that act as interference, and applying separate AMC decisions to concentrated slots and non-focused slots, can be expressed by the algorithm in <Table 1> below. .

Input: TDIA period , UE set , CSI/HARQ feedback
Output: data rate for IA or non-IA slot ( )
1: procedure TDIA-AMC
2: for each time t
3: if ( ) then
4: for all do
5: initialize
6: end for
7: end if
8: if ( ) then // IA slot
9: set
10: else // non-IA slot
11: set
12: end
13: for all do
14: if UE( )'s CSI feedback is received then
15: set
16: set
17: set
18: end if
19: if UE( )'s HARQ feedback is received then
20: set UE( )'s HARQ feedback delay
21: if ( ) then // IA slot
22: set
23: else // non-IA slot
24: set
25: end if
26: if HARQ feedback == ACK then
27:
28: else // NACK
29:
30: end if
31: end if
32: set
33: set
34: end for
35: end for
36: end procedure

Figure 5 illustrates an example of radio resource allocation when a concentrated slot is set according to various embodiments of the present disclosure.

Referring to Figure 5, traffic allocation in slot indices 0 to 11 is shown. Traffic may occur in the BO (Buffer occupancy) of the base station at slot index 2 (510). If a concentrated slot is not set, the base station can combine the traffic that acts as interference into Short BO and Heavy BO, allocate it to slot indexes 2, 3, 5 to 8, 10, and 11, and transmit it to the terminal. That is, if the concentrated slot is not set, traffic that acts as interference is randomly assigned, and a total of 8 slots (slot indices 2, 3, 5 to 8, 10, and 11) may be affected by interference.

On the other hand, when a concentrated slot is set, traffic that acts as interference can be collected and allocated to the concentrated slot. For example, referring to Figure 5, the intensive slot is set to slot index 5 (520). In the case of Short BO, the base station does not transmit traffic to the terminal at slot index 2 (510) where the traffic arrives at the BO, but may allocate and transmit traffic at slot index 5 (520). In addition, in the case of Heavy BO, the base station does not transmit traffic to the terminal at slot index 2 (510) where the traffic arrives at BO, but allocates traffic at slot index 5 (520). If the traffic exceeds the allocated radio resources, For excess traffic, the excess traffic can be allocated to slots after slot index 5 (520). That is, when a concentrated slot is set, traffic that acts as interference is collected and allocated to the concentrated slot, so a total of 6 slots (slot indices 5 to 8, 10, and 11) can be affected by interference.

In other words, if a centralized slot is set and the allocation of traffic is collected, sorted, and allocated to the concentrated slot, the number of slots to which interference-generating traffic is assigned may be reduced compared to the case where the concentrated slot is not set. As a result, the probability of interference is lowered and the data communication performance of the network can be improved.

Figure 6 illustrates the BO state of a base station when a concentrated slot is set according to various embodiments of the present disclosure. Specifically, it indicates the BO status of the base station when performing a TDIA operation.

Referring to FIG. 6, when the BO (Buffer occupancy) of the base station is empty, it may be referred to as an Empty state. When traffic occurs in the BO of a base station in the Empty state, the BO state of the base station may be filled with the generated traffic (Non-zero BO). At this time, the BO state of the base station may be referred to as the Wait state. At this time, the BO of the base station can maintain the Wait state without transmitting traffic to the terminal until the traffic reaches the concentration slot.

When traffic generated in the BO of the base station reaches the concentrated slot, the state of the BO may be changed to the Ready state. At this time, traffic arriving at the concentrated slot may be transmitted to the terminal. Even if additional traffic occurs later, the traffic is assigned to a concentrated slot and transmitted to the terminal, so the Ready state can be maintained. The detailed operation of this TDIA operation can be expressed by the algorithm in <Table 2> below.

Input : TDIA period , UE set
Output : decision on data transmission for each UE at each time slot
1: procedure TDIA
2: for each time slot
3: if ( ) then
4: for all do
5: initialize UE( ).state = " Empty "
6: end for
7: end if
8: if ( )) then // IA slot
9: AMC policy for IA slot will be applied
10: else // non-IA slot
11: AMC policy for non-IA slot will be applied
12: end if
13: for all do
14: if (UE( )'s traffic is arrived) then
15: if (UE( ).state == " Empty ") then
16: set UE ).state = " Wait "
17: end if
18: end if
19: if ( )) then // IA slot
20: if (UE( ).state == " Wait ") then
21: set UE ).state = " Ready "
22: end if
23: end
24: if (UE( ).state == " Ready ") then
25: transmission for UE( ) is allowed
26: else
27: transmission for UE(k) is not allowed
28: end
29: if (UE( )'s BO becomes empty) then
30: set UE ).state = " Empty "
31: end if
32: end for
33: end for
34: end procedure

Figure 7 shows a block diagram of resource allocation according to various embodiments of the present disclosure.

Referring to FIG. 7, the horizontal axis represents the frequency domain, and the vertical axis represents the time domain.

In the NR system, one transport block (TB) may include multiple code blocks (CB). A cyclic redundancy check (CRC) (not shown) may be added to the rear or front end of one TB to be transmitted in the uplink or downlink. The CRC may have 16 bits or 24 bits, a pre-fixed number of bits, or a variable number of bits depending on the channel situation, and can be used to determine whether channel coding is successful. In the NR system, the TB can be composed of multiple CBs without a separate division process. If even one CB has a CRC fail, a NACK judgment may be received indicating that transmission has failed for the entire TB.

The larger the transport block size (TB size, TBS), the larger the number of CBs can be. Because of this, the number of resource blocks that can be occupied per transport block may become small. As TBS becomes larger, it may be vulnerable to interference from a small number of RBs. In other words, as the TBS grows, if even one of the plurality of CBs included in the TB causes a CRC failure due to interference, the entire TB may be affected by the interference. For example, in FIG. 7, when at least one CB among CBs #3 to CB #5 constituting one TB has a CRC fail, a NACK decision indicating that the corresponding TB has failed in transmission may be received.

According to an embodiment of the present disclosure, the larger the TBS is, the more vulnerable it is to interference from the RB. Therefore, collecting the traffic of adjacent cells that act as interference in a specific concentrated slot for a certain period of time means that the traffic of the adjacent cells that act as interference is divided into several slots. The impact of interference may not be greater than if it is dispersed. In other words, even if the size of the RB acting as interference increases, if traffic from neighboring cells acting as interference is collected and assigned to a concentrated slot, the size of the RB acting as interference increases, but regardless of the size of the RB, the entire TB to which the CB belongs The difference in performance may not be significant in that it is affected by interference.

Figure 8 shows an example of the number of code-blocks (CB) and RB per CB according to modulation coding scheduling (MCS) level according to various embodiments of the present disclosure.

According to Figure 8, the number of CBs that can exist can be determined according to the MCS level and the level of Rank indicating the number of transport layers. For example, in the case of MCS 27, Rank 4, the number of CBs may be 129. Additionally, according to FIG. 8, the RB occupied per CB can be determined. For example, MCS 27, Rank 4 can occupy 23 RB per CB. According to an embodiment according to the present disclosure, in the case of MCS 27, Rank 4 in FIG. 8, when the size of traffic in a neighboring cell that acts as interference exceeds 23 RB, interference exceeding CB as long as it constitutes TB acts. Otherwise, the entire TB containing the relevant CB may receive a NACK decision as if interference has occurred. That is, if interference exceeds the size of the RB occupied by each CB, the decoding performance of the CB may not be significantly affected even if the RB size of the interference is larger. In other words, even if the size of the RB acting as interference increases by setting a concentrated slot, the negative impact on the throughput of data transmission is small. Rather, the number of slots acting as interference decreases, which improves data transmission performance as the total amount of interference is reduced. You can get the effect.

FIG. 9 illustrates a flow chart 900 between a centralized slot management device and cells according to various embodiments of the present disclosure.

Referring to FIG. 9, the centralized slot management device 920 may set a specific slot in the time domain to collect cell traffic to control inter-cell interference. (935) A specific slot in the time domain may be referred to as an interference aggregated slot or an interference slot. By setting a concentrated slot, traffic transmitted in a certain section can be aggregated and assigned to the concentrated slot.

The centralized slot management device 920 may be an entity on a network, may be an independent device, or may correspond to some functions of another network entity.

The centralized slot management device can preset the centralized slot. Specifically, the positions of centralized slots of cells managed by the centralized slot management device may be aligned identically. Additionally, the centralized slot for each cell may include the same operation period and offset settings.

According to an embodiment according to the present disclosure, radio resources allocated to cell traffic may be gathered and scheduled in a preset centralized slot.

The centralized slot management device 920 may transmit information about the centralized slots set to the serving cell 910 and the interference cell 930 connected to the centralized slot management device 920. (940) The serving cell 910 may refer to a serving base station that transmits data to a terminal, and the interference cell 930 may be adjacent to the serving base station and cause inter-cell interference in data transmission from the serving cell to the terminal. It may refer to a cell of an indirect base station.

According to an embodiment according to the present disclosure, the centralized slot management device may transmit information about the centralized slot having the same location for each cell to the plurality of cells managed by the centralized slot management device.

The serving cell 910 may collect and allocate traffic to be transmitted in a certain section to the concentrated slot based on information about the concentrated slot received from the concentrated slot management device 920. (945) If the traffic allocated to the concentrated slot exceeds the allocated radio resources, the serving cell may allocate the excess traffic to the next slot of the concentrated slot. According to an embodiment of the present disclosure, even if the next slot of the concentrated slot is a non-concentrated slot, a large portion of the traffic that interferes with the radio resources of the serving cell will have already been transmitted in the concentrated slot. The impact of allocated excess traffic on the serving cell can be minimized.

According to an embodiment according to the present disclosure, the serving cell may receive information about the concentrated slots of a plurality of neighboring cells from the concentrated slot management device. The serving cell may schedule traffic to the same concentrated slot as the concentrated slot of the plurality of neighboring cells based on information about the concentrated slot of the plurality of neighboring cells. At this time, the concentrated slots of the plurality of adjacent cells may be concentrated slots that have the same location for each adjacent cell.

Thereafter, the serving cell 910 may determine separate AMCs for the concentrated slot and the non-concentrated slot based on information about the concentrated slot. (950) According to an embodiment according to the present disclosure, if the past transmission in the intensive slot is ACK, the SINR of the intensive slot can be increased, and if the past transmission in the intensive slot is NACK, it can be lowered. If the past transmission in the non-concentrated slot was ACK, the SINR of the non-concentrated slot can be increased, and if it is NACK, it can be lowered. SINR can be increased by increasing the strength of the uplink received signal.

The adaptive modulation and coding selection (MCS) level is selected according to the signal SINR ratio of the channel through which data is transmitted and received. That is, a low MCS level is applied to concentrated slots, and a high MCS level is applied to non-intensive slots, so that a low data transmission rate can be applied to concentrated slots where the frequency of occurrence of inter-cell interference is expected to be high.

Finally, the serving cell 910 can transmit traffic in the concentrated slot to the terminal using a separately determined AMC. (955) At this time, the probability of occurrence of inter-cell interference in traffic transmitted to the terminal may be lower than the probability of occurrence of inter-cell interference in traffic when a concentrated slot is not set.

According to an embodiment according to the present disclosure, the serving cell may transmit traffic in the same concentrated slot as the concentrated slot of the neighboring cells of the plurality of adjacent cells to the terminal. At this time, the concentrated slots of the plurality of adjacent cells may be concentrated slots that have the same location for each adjacent cell.

The interference cell 930 may collect and allocate traffic of cells to be transmitted in a certain period to the concentrated slot based on information about the concentrated slot received from the concentrated slot management device 920. (960) Transmission may be delayed until traffic from the cell, which may act as interference, reaches the concentrated slot. As a result, cell traffic that may interfere with the concentrated slot may be collected, and the number of slots occupied by cell traffic may be reduced compared to the number of slots occupied by cell traffic before setting the concentrated slot. In other words, the number of slots acting as interference is reduced, thereby improving data transmission performance as the total amount of interference is reduced.

The interference cell 930 may transmit traffic from adjacent cells that act as interference gathered in the concentrated slot to the terminal. (965)

FIG. 10 illustrates an operation 1000 of a serving base station according to various embodiments of the present disclosure. The serving cell 910 may refer to a serving base station that transmits data to the terminal.

Referring to FIG. 10, in step 1010, the serving cell may receive information about the concentrated slot from the concentrated slot management device connected to the serving cell. Information about the concentrated slot may include information that sets a specific slot in a certain section as a slot to collect and allocate cell traffic.

In step 1020, the serving cell may aggregate traffic to be transmitted in a certain section into the concentrated slot and schedule it based on information about the concentrated slot.

According to an embodiment according to the present disclosure, when traffic allocated to a concentrated slot exceeds the allocated radio resources, the serving cell may allocate the excess traffic to the next slot of the concentrated slot. At this time, excess traffic can be allocated even if the slot next to the concentrated slot is a non-intensive slot.

In step 1030, the serving cell may determine separate AMCs for concentrated slots and non-concentrated slots. According to an embodiment according to the present disclosure, if the past transmission in the intensive slot is ACK, the SINR of the intensive slot can be increased, and if the past transmission in the intensive slot is NACK, it can be lowered. If the past transmission in the non-concentrated slot was ACK, the SINR of the non-concentrated slot can be increased, and if it is NACK, it can be lowered. SINR can be increased by increasing the strength of the uplink received signal.

In other words, a low MCS level can be applied to concentrated slots, and a high MCS level can be applied to non-concentrated slots, so that a low data transmission rate can be applied to concentrated slots where the frequency of occurrence of inter-cell interference is expected to be high.

In step 1040, the serving cell may transmit traffic in the concentrated slot to the terminal using a separately determined AMC. At this time, the probability of occurrence of inter-cell interference in traffic transmitted to the terminal may be lower than the probability of occurrence of inter-cell interference in traffic when a concentrated slot is not set.

FIG. 11 illustrates an operation 1100 of a neighboring base station according to various embodiments of the present disclosure. The adjacent cell may refer to a cell of the adjacent base station that is adjacent to the serving base station and may cause inter-cell interference in data transmission to the terminal of the serving cell. An adjacent cell may be referred to as an interference cell (eg, 930 in FIG. 9).

Referring to FIG. 11, in step 1110, an adjacent cell may receive information about a concentrated slot from a concentrated slot management device connected to the adjacent cell. Information about concentrated slots may include information that sets a specific slot in a certain section as a slot to collect and allocate cell traffic.

In step 1120, the adjacent cell may collect and schedule traffic that acts as interference to be transmitted in a certain period into a concentrated slot based on information about the concentrated slot received from the concentrated slot management device. Traffic that acts as interference may have transmission latency until it reaches the concentrated slot. Because of this, the traffic from adjacent cells that acts as interference in the concentrated slot can be collected, and the number of slots occupied by the traffic from adjacent cells that acts as interference is the number of slots occupied by the traffic from adjacent cells that acts as interference when the concentrated slot is not set. may be less than the number of

In step 1130, the adjacent cell may transmit traffic in the concentrated slot to the terminal.

FIG. 12 illustrates a graph of slot usage rate versus cycle time of intensive slots according to various embodiments of the present disclosure. Specifically, the results of a simulation based on traffic patterns collected from a commercial network are shown.

Referring to FIG. 12, the horizontal axis represents the time domain, and specifically, the period of the intensive slot set through the TDIA operation, which is an operation for setting the intensive slot to control inter-cell interference in the time domain. The vertical axis represents the utilization rate of a slot, and the slot utilization rate may mean the ratio of slots used to transmit traffic among all slots. When the slot utilization rate is high, there may be a high probability that in addition to the traffic intended to be transmitted by the serving cell, there will be a slot to which traffic from an adjacent cell, which acts as interference, is allocated. That is, slot utilization may indicate the possibility of potential inter-cell interference.

In FIG. 12, when traffic is transmitted without setting a concentrated slot (in the case of TDIA off), the slot utilization rate may be 22.7%. This may indicate that the probability of occurrence of potential inter-cell interference is 22.7%. In FIG. 12, when traffic is transmitted by setting the intensive slot (TDIA on), the slot utilization rate may be lower than the value of 22.7% as the operation period of the intensive slot increases. For example, if the operation section of the intensive slot is set to 10 slots, the slot utilization rate may be reduced to 15.2%. This may indicate that the probability of occurrence of potential inter-cell interference has been reduced to 15.2%. In other words, if traffic transmission is delayed for up to 10 slots and traffic is collected and allocated, the probability of inter-cell interference can be reduced by a total of 33%, from 22.7% to 15.2%.

Additionally, as the number of slots in the operation section of the intensive slot increases, the slot utilization rate may gradually decrease and then converge to a certain value. For example, in Figure 12, when the operation section of the intensive slot is set to 10 slots, the slot utilization rate is 15.2%, and when the operation section of the intensive slot is set to 30 slots, the slot utilization rate is 12.0%, which is 12.0% of the intensive slot. As the operation section increases, the slot utilization rate gradually decreases and then converges to a value of 10.4%.

FIG. 13 illustrates a graph of slot utilization versus the period of concentrated slots according to various embodiments of the present disclosure.

Referring to FIG. 13, the horizontal axis represents the time domain, and specifically represents the slot index when the operation section of the intensive slot is set to 10 slots. The vertical axis represents the utilization rate of a slot, and the slot utilization rate may mean the ratio of slots used to transmit traffic among all slots. When the slot utilization rate is high, there may be a high probability that in addition to the traffic intended to be transmitted by the serving cell, there will be a slot to which traffic from an adjacent cell, which acts as interference, is allocated. That is, slot utilization may indicate the possibility of potential inter-cell interference.

In FIG. 13, when traffic is transmitted without setting a concentrated slot in the downlink (DL) (in the case of TDIA off), the average value of slot utilization may be 22.7%. When a concentrated slot is set and traffic is transmitted (TDIA on), the average slot utilization rate can be 15.2%. In other words, it can be seen that the average value of slot utilization decreases from 22.7% to 15.2% when a concentrated slot is set to collect and allocate traffic from adjacent cells that act as interference, compared to when a concentrated slot is not set. This may mean that the probability of occurrence of potential inter-cell interference has been reduced from 22.7% to 15.2%.

Additionally, looking at the graph, when traffic is transmitted without setting a concentrated slot, traffic with interference is evenly distributed in each slot, so slot usage can be evenly distributed across all slots. On the other hand, when traffic is transmitted by setting a concentrated slot, traffic with interference is concentrated in and around the concentrated slot, so slot usage in the concentrated slot may be high.

Figure 14 shows a graph of data throughput versus signal to noise ratio (SNR) according to various embodiments of the present disclosure.

Referring to FIG. 14, the horizontal axis of the graph represents SNR, and the vertical axis represents the throughput of DL data. When data is processed without setting a conventional intensive slot, data throughput compared to SNR may be lower than when processing data with a conventional intensive slot set.

Additionally, even when transmitting traffic by setting up concentrated slots, it is more likely to collect and allocate traffic to concentrated slots and determine separate AMCs for non-focused slots other than the concentrated slots than to collect and allocate traffic to concentrated slots. Data throughput may be higher.

In other words, it can be confirmed that the case of processing data by collecting and allocating traffic from adjacent cells that act as interference to the concentrated slot shows higher data throughput than the case of processing data without setting the concentrated slot. This may mean that setting a concentrated slot can improve data processing performance. For example, in Figure 14, when a concentrated slot is set and separate AMCs are determined for the concentrated slot and a non-focused slot (TDIA on), the data throughput is compared to the data when the concentrated slot is not set (TDIA off). Throughput can be improved by 5 to 36 times more than throughput, and data throughput can be improved by 17% on average.

Figure 15 shows the structure of a base station 1500 according to various embodiments of the present disclosure.

Referring to FIG. 15, the base station 1500 includes a communication unit 1510, a storage unit 1520, and a control unit 1530.

The communication unit 1510 performs functions for transmitting and receiving signals through a wireless channel. For example, the communication unit 1510 performs a conversion function between baseband signals and bit strings according to the physical layer specifications of the system. For example, when transmitting data, the communication unit 1510 generates complex symbols by encoding and modulating the transmission bit string. Additionally, when receiving data, the communication unit 1510 restores the received bit stream by demodulating and decoding the baseband signal. Additionally, the communication unit 1510 upconverts the baseband signal into a radio frequency (RF) band signal and transmits it through an antenna, and downconverts the RF band signal received through the antenna into a baseband signal.

To this end, the communication unit 1510 may include a transmission filter, a reception filter, an amplifier, a mixer, an oscillator, a digital to analog convertor (DAC), an analog to digital convertor (ADC), etc. Additionally, the communication unit 1510 may include multiple transmission and reception paths. Furthermore, the communication unit 1510 may include at least one antenna array composed of a plurality of antenna elements. In terms of hardware, the communication unit 1510 may be composed of a digital unit and an analog unit, and the analog unit is divided into a number of sub-units according to operating power, operating frequency, etc. It can be configured.

The communication unit 1510 can transmit and receive signals. For this purpose, the communication unit 1510 may include at least one transceiver. For example, the communication unit 1510 may transmit a synchronization signal, reference signal, system information, message, control information, or data. Additionally, the communication unit 1510 can perform beamforming.

The communication unit 1510 transmits and receives signals as described above. Accordingly, all or part of the communication unit 1510 may be referred to as a ‘transmitting unit’, a ‘receiving unit’, or a ‘transmitting/receiving unit’. Additionally, in the following description, transmission and reception performed through a wireless channel are used to mean that the processing as described above is performed by the communication unit 1510.

The storage unit 1520 stores data such as basic programs, application programs, and setting information for operation of the base station. The storage unit 1520 may include memory. The storage unit 1520 may be comprised of volatile memory, non-volatile memory, or a combination of volatile memory and non-volatile memory. And, the storage unit 1520 provides stored data according to the request of the control unit 1530.

The control unit 1530 controls the overall operations of the base station 1500. For example, the control unit 1530 transmits and receives signals through the communication unit 1510. Additionally, the control unit 1530 writes and reads data into the storage unit 1520. Additionally, the control unit 1530 can perform protocol stack functions required by communication standards. For this purpose, the control unit 1530 may include at least one processor.

The configuration of the base station 1500 shown in FIG. 15 is only an example of a base station, and examples of base stations that perform various embodiments of the present disclosure are not limited to the configuration shown in FIG. 15. That is, according to various embodiments, some configurations may be added, deleted, or changed.

In FIG. 15, the base station 1500 is described as one entity, but the present disclosure is not limited thereto. The base station 1500 according to various embodiments of the present disclosure may be implemented to form an access network having an integrated deployment as well as a distributed deployment. According to one embodiment, the base station is divided into a central unit (CU) and a digital unit (DU), with the CU performing upper layer functions (e.g., packet data convergence protocol (PDCP, RRC)) and the DU performing lower layer functions. It can be implemented to perform (lower layers) (e.g. MAC (medium access control), PHY (physical)). The base station's DU can form beam coverage on the wireless channel.

Meanwhile, the embodiments of the present disclosure are merely provided as specific examples to easily explain the technical content of the present disclosure and aid understanding of the present disclosure, and are not intended to limit the scope of the present disclosure. In other words, it is obvious to those skilled in the art that other modifications based on the technical idea of the present disclosure can be implemented. Additionally, each embodiment can be operated in combination with each other as needed.

As described above, according to various embodiments of the present disclosure, a method performed by a serving cell in a wireless communication system includes receiving information about an aggregated slot from an aggregated slot management device; A step of aggregating and scheduling traffic to be transmitted in a certain section to a concentrated slot based on information about the concentrated slot, a step of determining separate adaptive modulation and coding (AMC) for the concentrated slot and the non-focused slot, and the determined AMC It may include transmitting traffic in the concentrated slot to the terminal using .

According to various embodiments of the present disclosure, the method may include allocating the excess traffic to a slot next to the intensive slot when the traffic allocated to the intensive slot exceeds the allocated radio resources.

According to various embodiments of the present disclosure, concentrated slots may be arranged in the same position across all cells of a base station managed by a concentrated slot management device.

According to various embodiments of the present disclosure, the concentration slot may be repeatedly set according to a preset cycle.

According to various embodiments of the present disclosure, determining the AMC may further include applying a low modulation coding scheduling (MCS) level to a concentrated slot and applying a high MCS level to a non-intensive slot.

As described above, according to various embodiments of the present disclosure, a serving cell device in a wireless communication system includes a transceiver and at least one processor, and the at least one processor includes, Receives information about aggregated slots from the aggregated slot management device, aggregates traffic to be transmitted in a certain section to the aggregated slots based on the information about the aggregated slots, and schedules them in the aggregated slots and non-aggregated slots. A separate adaptive modulation and coding (AMC) may be determined and configured to transmit traffic in the concentrated slot using the determined AMC.

According to various embodiments of the present disclosure, at least one processor may be configured to allocate excess traffic to a slot next to the concentrated slot when traffic allocated to the concentrated slot exceeds the allocated radio resources.

According to various embodiments of the present disclosure, concentrated slots may be arranged in the same position across all cells of a base station managed by a concentrated slot management device.

According to various embodiments of the present disclosure, the concentration slot may be repeatedly set according to a preset cycle.

According to various embodiments of the present disclosure, at least one processor may be configured to apply a low MCS (modulation coding scheduling) level to intensive slots and a high MCS level to non-intensive slots.

As described above, according to various embodiments of the present disclosure, a method performed by an interfering cell in a wireless communication system includes receiving information about an aggregated slot from an aggregated slot management device; It may include the steps of aggregating and scheduling traffic to be transmitted in a certain section to the concentrated slot based on information about the concentrated slot, and transmitting the traffic in the concentrated slot.

According to various embodiments of the present disclosure, the step of aggregating and allocating traffic to a concentrated slot may include waiting until the traffic is assigned to the closest concentrated slot among slots after the slot in which the traffic occurred.

According to various embodiments of the present disclosure, concentrated slots may be arranged in the same position across all cells of a base station managed by a concentrated slot management device.

According to various embodiments of the present disclosure, the concentration slot may be repeatedly set according to a preset cycle.

As described above, according to various embodiments of the present disclosure, a device of an interfering cell in a wireless communication system includes a transceiver and at least one processor, and the at least one processor includes, Receives information about aggregated slots from the aggregated slot management device, aggregates and schedules traffic to be transmitted in a certain section to the aggregated slot based on the information about the aggregated slot, and transmits the traffic in the aggregated slot. can be set.

According to various embodiments of the present disclosure, at least one processor may be set to aggregate and allocate traffic to a concentrated slot and wait until the traffic is assigned to the nearest concentrated slot among slots after the slot in which the traffic arrived. You can.

According to various embodiments of the present disclosure, concentrated slots may be arranged in the same position across all cells of a base station managed by a concentrated slot management device.

According to various embodiments of the present disclosure, the concentration slot may be repeatedly set according to a preset cycle.

Claims (18)

In a method performed by a serving base station in a wireless communication system,
Receiving information about an aggregated slot from an aggregated slot management device;
Aggregating and scheduling traffic to be transmitted in a certain period of time to concentrated slots based on the information about the concentrated slots;
determining separate adaptive modulation and coding (AMC) for the concentrated slot and the non-focused slot; and
Method comprising transmitting the traffic in the concentrated slot to the terminal using the determined AMC. In claim 1,
The above method is,
If the traffic allocated to the concentrated slot exceeds the allocated radio resources, allocating the excess traffic to the next slot of the concentrated slot. In claim 1,
The method wherein the centralized slots are arranged in the same position across all cells of the base station managed by the centralized slot management device. In claim 1,
The method wherein the concentration slot is repeatedly set according to a preset cycle. In claim 1,
The step of determining the AMC is,
applying a low modulation coding scheduling (MCS) level to the concentrated slot; and
The method further comprising applying a high MCS level to the non-intensive slot. In the device of a serving base station in a wireless communication system,
transceiver; and
Contains at least one processor,
The at least one processor,
Receive information about aggregated slots from the aggregated slot management device,
Based on the information about the concentrated slot, traffic to be transmitted in a certain period is aggregated and scheduled in the concentrated slot,
Determine separate adaptive modulation and coding (AMC) for the concentrated slot and the non-focused slot,
A device configured to transmit the traffic in the concentrated slot to the terminal using the determined AMC. In claim 6,
The at least one processor,
The device is configured to allocate excess traffic to the next slot of the intensive slot when the traffic allocated to the intensive slot exceeds the allocated radio resources. In claim 6,
The centralized slot is arranged in the same position across all cells of the base station managed by the centralized slot management device. In claim 6,
The device wherein the concentration slot is repeatedly set according to a preset cycle. In claim 6,
The at least one processor,
A low MCS (modulation coding scheduling) level is applied to the concentrated slot,
A device configured to apply a high MCS level to the non-intensive slot. In a method performed by a neighboring base station in a wireless communication system,
Receiving information about an aggregated slot from an aggregated slot management device;
Aggregating and scheduling traffic to be transmitted in a certain section to a concentrated slot based on the information about the concentrated slot; and
Method comprising transmitting the traffic in the concentrated slot to a terminal. In claim 11,
The step of aggregating and scheduling the traffic into the concentrated slot is,
A method comprising waiting for the traffic to be scheduled in the most adjacent concentrated slot among slots after the slot in which the traffic occurred. In claim 11,
The method wherein the centralized slots are arranged in the same position across all cells of the base station managed by the centralized slot management device. In claim 11,
The method wherein the concentration slot is repeatedly set according to a preset cycle. In the device of a neighboring base station in a wireless communication system,
transceiver; and
Contains at least one processor,
The at least one processor,
Receive information about aggregated slots from the aggregated slot management device,
Based on the information about the concentrated slot, traffic to be transmitted in a certain period is aggregated and scheduled in the concentrated slot,
A device configured to transmit the traffic in the concentrated slot to a terminal. In claim 15,
The at least one processor,
The traffic is scheduled by aggregating it into the concentrated slot,
A device configured to wait until the traffic is assigned to the most adjacent concentrated slot among slots after the slot in which the traffic occurred. In claim 15,
The centralized slot is arranged in the same position across all cells of the base station managed by the centralized slot management device. In claim 15,
The device wherein the concentration slot is repeatedly set according to a preset cycle.

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