KR102612167B1 - Method and apparatus for determining transmission priority of beam component carriers in communication system - Google Patents

Abstract

In a base station of a communication system that divides the frequency band of each of the plurality of beams into a plurality of FAs (Frequency Allocations) called beam element carriers, a device that determines the transmission priority of the beam element carriers provides a serving beam for the connected terminal. A beam mapper that sets, and transmission priorities of the FAs included in the terminal's activated FA set, including FAs activated for transmission using CQI reporting data including CQI information of the serving beam reported from the terminal It includes a scheduler that determines and schedules data to be transmitted to the terminal according to the transmission priorities of the FAs.

Description

Method and apparatus for determining transmission priority of beam component carriers in a communication system {METHOD AND APPARATUS FOR DETERMINING TRANSMISSION PRIORITY OF BEAM COMPONENT CARRIERS IN COMMUNICATION SYSTEM}

The present invention relates to a method and apparatus for determining the transmission priority of beam component carriers in a communication system. In particular, a method for determining the transmission priority of FA (Frequency Allocation), called the component carrier of each beam, in a communication system using multiple beams. and devices.

5G technology, which will be commercialized after 2020, aims to provide services that support 1,000 times the transmission capacity of 4G anytime, anywhere. However, spectral efficiency has almost reached the Shannon limit, which is referred to as the theoretical limit, and other technological alternatives are needed.

Meanwhile, in IMT (International Mobile Telecommunications)-Advanced technology, a method of transmitting and receiving using a wide bandwidth to meet the data transmission speed was presented as an alternative. 3GPP set the maximum supported bandwidth of LTE-A (Long Term Evolution Advanced) at 100MHz. However, due to the lack of frequency resources that can be allocated with a single 100MHz bandwidth, CA (Carrier aggregation) technology was introduced. CA technology is a communication technology that enables broadband transmission by integrating multiple small frequency bandwidths. CA technology has the problem of being technically difficult and increasing product costs compared to technologies using a single broadband.

Meanwhile, while an LTE terminal using multi-carrier technology can transmit up to 75Mbps in a single frequency bandwidth, an LTE-A terminal supporting CA technology can transmit up to 150Mbps by combining two frequency bandwidths. In 3GPP, various CA combinations are defined for each release, and each carrier frequency band that makes up the CA combination is defined as a component carrier (CC).

When using CA, the terminal can connect to the base station using one primary CC and multiple secondary CCs. Therefore, the terminal can use up to 100 MHz by simultaneously bundling up to 5 frequencies with a bandwidth of up to 20 MHz, including the main CC. Currently, 3GPP TS 36.101 defines a total of 43 frequency bands and various CA combinations. The defined CA combination can be further classified into an intra-band CA combination that binds the same frequency band and an inter-band CA combination that binds different frequency bands. And intra-band CA combinations can be further classified into Contiguous CA and Non-contiguous CA. This is because the frequency bands allocated and used by each network operator are different.

In this conventional technology, even if CC technology is applied to support a bandwidth of up to 100 MHz, 5G technology that will be commercialized after 2020 cannot meet the demand for a transmission speed of 1000 times that of 4G. Additionally, there is a lack of additional radio frequency resources to support this in the current band below 6GHz. To solve these problems, an approach that seeks to use the millimeter wave band of 6 GHz or higher for cellular communication is being proposed as an alternative in 5G technology. In general, millimeter waves are resistant to interference but have the characteristic of high signal attenuation. This characteristic can be overcome by applying beam forming technology. Therefore, the base station can increase transmission efficiency to the terminal and expand transmission coverage by generating multiple beams using beam forming technology and concentrating transmission power into a narrow area of the beam.

Meanwhile, in the beamforming base station, each beam uses the same frequency band to maximize frequency reuse efficiency. And since available frequency resources are relatively abundant in the millimeter wave band, each beam can use a bandwidth of 1 GHz or more to increase transmission. However, with current technology, broadband transmission and reception above 1 GHz increases the complexity of wireless devices for both base stations and terminals. Therefore, beams using a wide bandwidth need to be configured and operated as multiple beam CCs by applying the CA technique. That is, each beam is composed of smaller beam CCs that operate independently, and the terminal receives services by accessing multiple specific beam CCs among the specific beams operated by the base station. Therefore, the base station must be able to receive CQI information for each beam CC within multiple beams from the terminal and schedule them according to priority.

However, the complexity of scheduling of the beam forming base station increases depending on the number of surrounding base stations, the number of beams operated by the base station, and the number of beam CCs. Also, there is a problem that the amount of uplink CQI information increases as a product of these values. In particular, millimeter wave-based base stations are suitable for small base stations due to their signal characteristics, so there is a problem in that the amount of CQI information further increases because multiple base stations can be installed in a narrow area. In addition, due to the characteristics of millimeter waves, even small movements of the user cause many changes in the radio wave environment for each beam CC. In order to increase the accuracy of CQI information for each beam CC, the measurement period must be shortened, so the uplink CQI transmission amount is greatly reduced. It increases.

The problem that the present invention aims to solve is to minimize the amount of CQI information reported for each beam element carrier of each beam of the terminal and to determine the transmission priority of the beam element carrier using the CQI information for each beam element carrier of each beam reported from the terminal. To provide a method and device for determining transmission priority of beam element carriers in a communication system.

According to an embodiment of the present invention, a method of determining the transmission priority of the beam element carrier at a base station of a communication system that divides the frequency band of each of the plurality of beams into a plurality of FAs (Frequency Allocation) called beam element carriers. This is provided. A method for determining the transmission priority of a beam element carrier includes receiving CQI reporting data including CQI information of a serving beam of a serving cell from a terminal, and based on the CQI information of the serving beam, at least one of the active FAs included in the set of the terminal. Determining the transmission priority of one FA, and scheduling data to be transmitted to the terminal according to the transmission priority of the at least one FA, wherein the CQI information of the serving beam is provided to each of the plurality of FAs. Includes a CQI report value, the CQI report value of the main FA among the plurality of FAs includes the entire CQI measurement value, and the CQI report value of each of the secondary FAs other than the main FA among the plurality of FAs is the main FA. Includes the difference between the CQI measurement value and the CQI measurement value of the corresponding department FA.

The CQI report data further includes CQI information of the neighboring beam of the serving cell and CQI information of beams of the neighboring cell, and the method for determining transmission priority of the beam element carrier is performed using the CQI information of the CQI report data for handover. It further includes the step of determining beam switching, wherein the CQI information of the neighboring beam of the serving cell includes the CQI average value of the CQI measurement values of a set number of FAs with high intra-beam CQI measurement values for each beam identifier, and the neighboring beam The CQI information of the beams of the cell may include the average CQI value of the CQI measurement values of a set number of FAs with high CQI measurement values according to each beam identifier.

The step of determining handover or beam switching is performed when the average CQI value of the neighboring beam within the serving beam is greater than or equal to the CQI average value of the CQI measurements of the set number of FAs within the activated FA set, to the neighboring beam within the serving beam. It may include determining beam switching.

The step of determining handover or beam switching may further include performing beam switching to the neighboring beam and then initializing and resetting the activated FA set of the terminal based on received CQI report data.

The step of determining the handover or beam switching is performed when the CQI average value of any one beam in the neighboring beam is greater than or equal to the CQI average value of the CQI measurements of the set number of FAs in the activated FA set. It may include determining handover with one beam.

The set number of FAs may include a primary FA and secondary FAs with high CQI measurements among the maximum number of FAs that the terminal can receive and process.

The method for determining transmission priority of the beam element carrier may further include changing the FA in the activated FA set of the terminal based on CQI information of the serving beam.

The changing step includes determining the FA to be activated and the FA to be deactivated based on the CQI reporting value of each of the plurality of FAs, adding the FA to be activated to the activated FA set, and selecting the FA to be deactivated as the activated FA. May include removing from the set.

The changing step may further include activating an FA added to the activated FA set and generating a MAC CE to deactivate an FA removed from the activated FA set and transmitting the MAC CE to the terminal.

According to another embodiment of the present invention, the base station of a communication system that divides the frequency band of each of the plurality of beams into a plurality of FAs (Frequency Allocation) called beam element carriers determines the transmission priority of the beam element carriers. A device is provided. The apparatus for determining the transmission priority of a beam element carrier includes a beam mapper and a scheduler. The beam mapper sets the serving beam for the connected terminal. And the scheduler determines the transmission priority of the FAs included in the terminal's activated FA set including FAs activated for transmission using CQI reporting data including CQI information of the serving beam reported from the terminal. And, data to be transmitted to the terminal is scheduled according to the transmission priorities of the FAs.

The CQI information of the serving beam includes the CQI report value of each of the plurality of FAs, and the CQI report value of the main FA among the plurality of FAs includes the entire CQI measurement value, excluding the main FA among the plurality of FAs. The CQI report value of each of the remaining sub-FAs may include the difference between the CQI measurement value of the main FA and the CQI measurement value of the corresponding sub-FA.

The CQI report data further includes CQI information of the neighboring beam of the serving cell and CQI information of the beams of the neighboring cell, and the CQI information of the neighboring beam of the serving cell is a set number of beams with a high intra-beam CQI measurement value for each beam identifier. It includes the CQI average value of the CQI measurement values of FAs, and the CQI information of the beams of the neighboring cells may include the CQI average value of the CQI measurement values of a set number of FAs with high CQI measurement values according to each beam identifier for each cell identifier. You can.

The beam mapper may determine handover or beam switching based on the average CQI value of neighboring beams within the serving beam and the average CQI value of beams of the neighboring cell.

If the average CQI value of the neighboring beam in the serving beam is greater than or equal to the CQI average value of the CQI measurements of the set number of FAs in the activated FA set, the beam mapper may determine beam switching to the neighboring beam in the serving beam. .

If the CQI average value of any one beam in the neighboring beam is greater than or equal to the CQI average value of the CQI measurements of the set number of FAs in the activated FA set, the beam mapper performs handover to any one beam in the neighboring beam. You can decide.

The scheduler may change the FA in the activated FA set based on the CQI report value of each of the plurality of FAs.

The scheduler determines the FA to be activated and the FA to be deactivated based on the CQI reporting value of each of the plurality of FAs, adds the FA to be activated to the activated FA set, and removes the FA to be deactivated from the activated FA set. You can.

According to an embodiment of the present invention, the amount of CQI information reported from the terminal can be reduced, and data can be scheduled by determining the transmission priority of the beam element carrier based on the CQI information reported from the terminal.

Figure 1 is a diagram showing a millimeter wave-based communication system according to an embodiment of the present invention.
Figure 2 is a diagram showing an example of FA for each beam according to an embodiment of the present invention.
Figure 3 is a diagram showing an example in which a terminal uses multiple FAs in a specific beam according to an embodiment of the present invention.
Figure 4 is a diagram showing the structure of a base station and a terminal according to an embodiment of the present invention.
Figure 5 is a diagram explaining a CQI reporting method of a terminal according to an embodiment of the present invention.
Figure 6 is a flowchart showing a data transmission method according to the transmission priority of the FA in the base station according to an embodiment of the present invention.

Below, with reference to the attached drawings, embodiments of the present invention will be described in detail so that those skilled in the art can easily implement the present invention. However, the present invention may be implemented in many different forms and is not limited to the embodiments described herein. In order to clearly explain the present invention in the drawings, parts that are not related to the description are omitted, and similar parts are given similar reference numerals throughout the specification.

Throughout the specification and claims, when a part is said to “include” a certain component, this means that it may further include other components rather than excluding other components, unless specifically stated to the contrary.

Throughout the specification, terminal refers to a mobile terminal (MT), a mobile station (MS), an advanced mobile station (AMS), and a high reliability mobile station (HR-MS). , may refer to a subscriber station (SS), portable subscriber station (PSS), access terminal (AT), user equipment (UE), etc., MT, MS, AMS , may include all or part of the functions of HR-MS, SS, PSS, AT, UE, etc.

In addition, the base station (BS) is an advanced base station (ABS), a high reliability base station (HR-BS), a node B, an evolved node B, eNodeB), access point (AP), radio access station (RAS), base transceiver station (BTS), mobile multihop relay (MMR)-BS, relay that acts as a base station station (RS), a relay node (RN) that acts as a base station, an advanced relay station (ARS) that acts as a base station, and a high reliability relay station (HR) that acts as a base station. -RS), small base station [femto BS, home node B (HNB), home eNodeB (HeNB), pico BS, metro BS, micro BS ), etc.], etc., and may include all or part of the functions of ABS, NodeB, eNodeB, AP, RAS, BTS, MMR-BS, RS, RN, ARS, HR-RS, small base station, etc. there is.

Now, a method and device for determining transmission priority of a beam element carrier in a communication system according to an embodiment of the present invention will be described in detail with reference to the drawings.

Figure 1 is a diagram showing a millimeter wave-based communication system according to an embodiment of the present invention.

Referring to FIG. 1, a millimeter wave-based mobile communication system includes a beam forming base station (hereinafter referred to as “base station”) 100 and at least one terminal 200.

The base station 100 communicates with the terminal 200 using the millimeter wave band.

The millimeter wave band is easier to allocate wide and continuous wireless resources compared to the 6 GHz or lower bands used in existing mobile communication networks, making it possible to increase the capacity of the communication system. However, since the millimeter wave band has strong straightness and propagation loss, the base station 100 uses beam forming technology to overcome this.

The base station 100 generates a plurality of beams (B1 to Bn) within a cell through beam forming and operates the plurality of beams (B1 to Bn). Each of the plurality of beams (B1 to Bn) has a unique beam identifier, and each beam (B1 to Bn) may partially overlap with an adjacent beam.

Beamforming technology can be classified into fixed and adaptive beamforming technology. Fixed beams generated by fixed beam forming technology each have a set beam direction and beam size. The base station 100 can generate multiple beams (B1 to Bn) to cover the entire cell.

Some of the plurality of beams (B1 to Bn) may be grouped to form a sector. For example, the base station 100 can generate and operate 48 beams, and the 48 beams can cover the entire cell. And 16 beams can be grouped to form one sector.

Each beam within a sector (or cell) has the same cell specific-reference signal (CRS) position. Therefore, each beam within the base station 100 has the same cell identifier but different beam identifiers. That is, different beam state information-reference signals (BSI-RS) are assigned to each beam within the same sector. Here, BSI-RS may be the same or similar to the concept of CSI-RS of LTE.

Additionally, each beam within a sector (or cell) broadcasts the same system information, that is, Master Information Block (MIB) and System Information Block (SIB) information.

In the millimeter wave band, available frequency resources are relatively abundant, so each beam (B1 to Bn) can use a bandwidth of 1 GHz or more. Additionally, each beam (B1 to Bn) performs services using the entire frequency band of 1 GHz. That is, all beams (B1 to Bn) use the same frequency band and the same time slot, and multiple terminals belonging to the same beam communicate with the base station 100 by being assigned orthogonal components divided in the time or frequency domain.

However, broadband transmission and reception of 1 GHz or more increases the complexity of wireless devices for both the base station 100 and the terminal 200. For example, wideband transmission and reception increases the sampling rate of the transmitter and receiver, which directly affects the power consumption and complexity of the DAC/ADC as well as the front-end digital signal processing. RF components also generally have the problem that in order to support a wide bandwidth, the design itself becomes complicated and the manufacturing price also increases. Therefore, each beam using a wide bandwidth needs to apply the CA technique to divide the wide bandwidth into multiple frequency allocation bands (Frequency allocation, FA) called beam element carriers. Below, the beam element carrier is referred to as FA.

Figure 2 is a diagram showing a plurality of FAs according to an embodiment of the present invention.

Referring to FIG. 2, each beam (B1 to Bn) operates by dividing the entire frequency band into a plurality of FA (Multiple Frequency Allocations) (FA1 to FAk). In Figure 2, only one beam (Bi) is shown among the plurality of beams (B1 to Bn).

For example, if the total frequency band of the beams (B1 to Bn) is 1 GHz, they can be divided into 8 frequency assignments (FA) with a bandwidth of 125 MHz and operated.

In this way, when each beam (B1 to Bn) is divided and operated by a plurality of FAs, the terminal 200 receives service by accessing at least one FA among the plurality of FAs of a specific beam.

For the same FA of all beams in the same cell, Primary synchronization signal (PSS), Secondary synchronization signal (SSS), Physical Broadcast Channel (PBCH), Physical Control Format Indicator Channel (PCFICH), Physical Hybrid ARQ Indicator Channel (PHICH), PDCCH ( Physical Downlink Control Channel), PUCCH (Physical Uplink Control Channel), and PRACH (Physical Random Access Channel) are commonly operated.

Meanwhile, the operation of each FA (FA1 to FAk) is similar to the operation of CC (Component Carrier) in CA (Carrier aggregation) described in the prior art. However, due to the characteristics of the millimeter wave band, the bandwidth of each FA (FA1 to FAk) can be 125 MHz or more, and the number of FAs that can be added can be more than 5.

Among multiple FAs (FA1 to FAk), one FA is used as the primary FA, and the remaining FAs are used as secondary FAs. The terminal 200 performs an initial connection process using the primary FA. The terminal 200 may perform an initial connection process by transmitting a Radio Resource Control (RRC) connection request message or an RRC connection re-establishment request message to the base station 100 using the primary FA.

The base station 100 can add or remove a secondary FA using an RRC connection reconfiguration message. The main FA consists of a pair of uplink FA and downlink FA and is always active. On the other hand, the secondary FA is in a deactivated state, and the base station 100 activates or deactivates the secondary FA using the MAC CE (Control element).

The terminal 200 measures the CQI for each FA (FA1 to FAk) of the serving beam and neighboring beam and reports the CQI information for each FA (FA1 to FAk) of each beam to the base station 100 through the PUCCH. The base station 200 transmits a BSI-RS through the FAs (FA1 to FAk) of the serving beam and neighboring beams, and the terminal 200 uses the received BSI-RS to each FA (FA1 to FAk) of each beam. CQI information can be measured.

The base station 100 may determine beam switching within the same cell of the terminal 200 based on the CQI information for the FAs (FA1 to FAk) of each beam reported from the terminal 200. That is, the terminal 200 can perform beam switching to another beam in the same cell according to the decision of the base station 100.

Additionally, the base station 100 may determine inter-cell beam switching based on CQI information for the FAs (FA1 to FAk) of each beam of the neighboring base station received from the neighboring base station. The terminal 200 may perform beam switching to the beam of a neighboring base station according to the decision of the base station 100.

At this time, beam switching within the same cell can be performed at the MAC (Media Access Control) layer using DCI (Downlink Control Information) of the PDCCH, and beam switching to another cell can be performed using the handover procedure of the RRC layer. there is.

Figure 3 is a diagram showing an example in which a terminal uses multiple FAs in a specific beam according to an embodiment of the present invention.

Referring to FIG. 3, the terminal 200 has a main FA (FA1) and a number of secondary FAs (e.g., FA4, FA6) among the eight FAs (FA1 to FA8) operating within the 1 GHz bandwidth of a specific beam (Bi). ) can be selected to connect to the base station 100.

The frequency band that the terminal 200 can receive may be limited to M FAs. Here, M may vary depending on the performance or implementation of the terminal 200.

The terminal 200 accesses the serving beam using the primary FA (FA1) and then adds secondary FAs (FA4, FA6) according to the user's request. Therefore, in terms of scheduling of the base station 100, the performance of the terminal 200 can be determined depending on which beam it accesses and which FA within the beam it uses. Additionally, when the terminal 100 uses multiple FAs, the performance of the terminal 200 may vary depending on which FA is scheduled preferentially.

Therefore, the base station 100 receives the CQI information for each FA (FA1 to FA8) in each beam (B1 to Bn) from the terminal 200, determines the transmission priority of each FA (FA1 to FA8), and determines the transmission priority of each FA. Data to be transmitted to the terminal 200 is scheduled according to the transmission priority.

Figure 4 is a diagram showing the structure of a base station and a terminal according to an embodiment of the present invention.

The base station 100 includes a transmitter 110 and a receiver 120. The transmitter 110 may correspond to a transmission priority determination device for beam element carriers according to an embodiment of the present invention.

The transmitter 110 includes a Packet Data Convergence Protocol (PDCP)/Radio Link Control (RLC) processor 112, a beam mapper 114, and a MAC processor 116. The PDCP/RLC processor 112, beam mapper 114, and MAC processor 116 of the transmitter 110 are connected to at least one processor implemented with a central processing unit (CPU) or other chipset, microprocessor, etc. It can be performed by And instructions for execution by the processor may be loaded or stored in memory or a storage device. The processor can perform the operations described below by executing instructions loaded or stored in memory. The processor and memory are connected to each other through a bus (not shown), and an input/output interface (not shown) may also be connected to the bus. At this time, a transceiver is connected to the input/output interface, and peripheral devices such as an input device, display, speaker, and storage device may be connected.

The PDCP/RLC processor 112 processes radio bearers for the terminal 200 connected to the base station 100. For example, the PDCP/RLC processor 112 may set up radio bearers (RB#1, RB#p) for the terminal 200.

The beam mapper 114 maps the connected terminal 200 to one beam among the plurality of beams B1 to Bn. That is, the beam mapper 114 can set the serving beam of the connected terminal 200. For example, the beam mapper 114 maps the connected terminal 200 to the beam B1, and sends data of the radio bearers (RB#1, RB#p) set to the terminal 200 to the MAC processor 116. It is transmitted to the beam processor (1162 _{1) corresponding to the beam B1 among the plurality of beam processors (1162 1 to} 1162 _n ). Below, for convenience, it is explained that the terminal 200 is mapped to the beam B1.

The MAC processor 116 includes a scheduler 1161 and a plurality of beam processors 1162 ₁ to 1162 _n .

The plurality of beam processors 1162 ₁ to 1162 _n each form a plurality of beams B1 to Bn and process data transmitted through the plurality of beams B1 to Bn. Each beam processor (1162 ₁ to 1162 _n ) includes a plurality of FA processors (1163 ₁ to 1163 _k ). A plurality of FA processors (1163 ₁ to 1163 _k ) each process data transmitted through a plurality of FAs (FA1 to FAk). A plurality of FA processors (1163 ₁ to 1163 _k ) in the beam processor (1162 ₁ to 1162 _n ) may each perform a Hybrid Automatic Repeat reQuest (HARQ) function.

The scheduler 1161 creates and manages a set of activated FAs of the terminal 200. The activated FA set refers to a set that has as elements FAs that the base station 100 activates for radio bearer transmission of a specific terminal.

In addition, the scheduler 1161 uses the CQI information for each FA of each beam reported from the terminal 200 to determine the transmission priority of each FA and schedules data of the radio bearer set in the terminal 200.

By the beam mapper 114, the terminal 200 is mapped to a specific beam (for example, B1) during the initial access process and establishes a connection with the base station 200 using the primary FA. The primary FA is determined by the base station operator when the base station 100 is installed, and information on the primary FA may be transmitted to the terminal 200 through a System Information Block (SIB).

The scheduler 1161 causes the terminal 200 to add the remaining FAs except the primary FA in the beam as secondary FAs using an RRC connection reconfiguration message. As described above, the scheduler 1161 may use the RRC connection reconfiguration message to add or remove the secondary FA of the terminal 200.

Meanwhile, the scheduler 1161 additionally activates the secondary FA to satisfy QoS when setting up the radio bearers (RB#1, RB#p) of the terminal 200. The scheduler 1161 creates an activated FA set for the terminal 200 during the initial access process of the terminal 200 and adds the primary FA to the activated FA set. Additionally, the scheduler 1161 may add additional activated secondary FAs to the active FA set to satisfy QoS requirements when setting up a radio bearer of the terminal 200. Therefore, the set of activated FAs of the terminal 200 may include the primary FA and secondary FAs that are additionally activated when setting up a radio bearer.

The terminal 200 may include a MAC reception processor 210 and a MAC transmission processor 220. MAC receive processor 210 includes a beam processor 212 and a measurement processor 214. The beam processor 212 includes a plurality of FA processors (2121 ₁ to 2121 _n ).

The beam processor 212 processes signals received from the base station 100 through a specific beam. A plurality of FA processors 2121 ₁ to 2121 _n in the beam processor 212 each process signals received through FAs included in the activated FA set of the terminal 200 among the plurality of FAs (FA1 to FAk). That is, the FA processors 1163 ₁ to 1163 _k of the beam processor (e.g., 1162 ₁ ) corresponding to a specific beam of the base station 100 to which the terminal 200 is mapped are located within the beam processor 212 of the terminal 200. It corresponds one-to-one with multiple FA processors (2121 ₁ to 2121 _m ). Here, m≤k.

For example, when the radio bearer (RB#p) of the terminal 200 is mapped to the beam (B1), it is included in the active FA set among the plurality of FA processors (1163 ₁ to 1163 _k ) in the beam processor (1162 ₁ ). The two FA processors 1163 ₁ and 1163 ₂ for the FAs have a one-to-one correspondence with the two FA processors (eg, 2121 ₁ and 2121 ₂ ) in the beam processor 212.

When each of the plurality of FA processors (2121 ₁ to 2121 _n ) in the beam processor 212 receives a signal through the FAs included in the active FA set among the plurality of FAs (FA1 to FAk), HARQ feedback information for the received signal Generates and delivers HARQ feedback information to the MAC transmission processor 220. A plurality of FA processors (2121 ₁ ~ 2121 _m ) each generate a positive response (ACK) feedback as HARQ feedback if the decoding of the received data is successful, and a negative response (NACK) as HARQ feedback if the decoding of the received data fails. Feedback can be generated. In addition, when the FA processor (2121 ₁ to 2121 _n ) receives a BSI-RS through FAs included in the active FA set among a plurality of FAs (FA1 to FAk), it measures the CQI from the received BSI-RS and CQI information is delivered to the MAC transmission processor 220.

The measurement processor 214 receives data from the FAs not included in the activated FA set from the BSI-RS received through FAs not included in the activated FA set among the plurality of FAs (FA1 to FAk) of each beam (B1 to Bm). CQI is measured, and the measured CQI information is transmitted to the MAC transmit processor 220. That is, the measurement processor 214 measures CQI for deactivated FAs.

The MAC transmission processor 220 includes a beam processor 222, and the beam processor 222 transmits HARQ feedback information of FAs included in the activated FA set to the base station 100 through a beam to which the terminal 200 is mapped. do. Additionally, the beam processor 222 transmits CQI information for the FAs (FA1 to FAk) of each beam (B1 to Bm) to the base station 100.

The receiver 120 of the base station 100 includes a PDCP/RLC processor 122 and a MAC processor 124. The MAC processor 124 includes a beam processor 1241, which receives HARQ feedback information of FAs included in the activated FA set transmitted through a beam from the terminal 200 and sends the activated FA set to the activated FA set. The HARQ feedback information of the included FAs can be transmitted to the scheduler 1161 of the transmitter 110 and the beam processor 1162 ₁ that processes the beam mapped to the terminal 200. Additionally, the beam processor 1241 transmits CQI information for a plurality of FAs (FA1 to FAk) of each beam (B1 to Bm) to the beam mapper 114.

The PDCP/RLC processor 122 processes data of the radio bearer established for the terminal 200 using the PDCP/RLC protocol.

In general, when data of a radio bearer (e.g., RB#p) is transmitted using multiple FAs in an active FA set, the transmission priority of each FA is based on CQI information reported at regular intervals from the terminal 200. do. Therefore, there is a problem that the amount of uplink CQI information increases in proportion to the product of the number of neighboring base stations, the number of beams operated by the base station, and the number of FAs in each beam. In particular, the millimeter wave-based base station 100 is suitable for small base stations due to signal characteristics, so there is a problem in that the amount of uplink CQI information further increases because multiple base stations can be installed in a narrow area. In addition, due to the characteristics of millimeter waves, even small movements of the user cause many changes in the propagation environment for each FA of each beam. In order to increase the accuracy of CQI information for each FA of each beam, the CQI measurement period must be shortened, so uplink CQI The amount of transmission increases further. Therefore, a CQI reporting method is needed to minimize the amount of CQI information transmitted in the uplink.

Figure 5 is a diagram explaining a CQI reporting method of a terminal according to an embodiment of the present invention.

Referring to FIG. 5, the measurement processor 214 of the terminal 200 measures CQI information for the serving beam and neighboring beam of the serving cell and CQI information for beams of the neighboring cell, and the measured CQI information is described below. It is reported to the base station 100 in this way.

The CQI report of the serving beam of the serving cell includes the CQI report value of all FAs (FA1 to FAk) of the serving beam. At this time, among all FAs (FA1 to FAk), the CQI reported value of the main FA includes the entire CQI measurement value of the main FA, and the CQI reported value of the secondary FA excluding the main FA among all FAs includes the CQI measurement value of the main FA and the secondary FA. Includes the difference value of the CQI measurement value. That is, the measurement processor 214 measures the CQI of all FAs (FA1 to FAk) of the serving beam, reports all CQI measured values for the main FA, and reports all CQI measured values of the secondary FA for the secondary FA. Rather, the difference between the CQI measurement value of the primary FA and the CQI measurement value of the secondary FA is reported to the base station 100. According to the CQI report of the serving beam of the serving cell, the uplink CQI transmission amount may be reduced.

The CQI report of the neighboring beam of the serving cell includes the number of neighboring beams, the beam identifier of each neighboring beam, and the average CQI value for m FAs in the beam corresponding to the beam identifier. The number of neighboring beams indicates the number of neighboring beams from which the terminal 200 can receive signals within the serving cell. The beam identifier indicates the beam identifier of the neighboring beam to be currently reported. The CQI average value for m FAs represents the CQI average value for m FAs among the k FAs (FA1 to FAk) transmitted by the base station 100 within the corresponding beam. The measurement processor 214 calculates the average value of the CQI measurements for the main FA and the highest (m-1) minor FAs among the CQI measurements for the k FAs (FA1 to FAk) measured in each neighboring beam, CQI average values according to the number of neighboring beams and the beam identifiers of the neighboring beams are reported to the base station 100. At this time, m means the maximum number of FAs that the terminal 200 can receive and process.

The CQI report of a beam belonging to a neighboring cell includes the number of cells, a cell identifier, and CQI information of the beam corresponding to the cell identifier. The CQI information of the beam corresponding to the cell identifier is reported in the same manner as the CQI report of the neighboring beam of the serving cell described above. That is, the CQI information of the beam corresponding to the cell identifier includes the number of beams, the beam identifier of each beam, and the average CQI value for m FAs in the beam corresponding to the beam identifier. The number of cells indicates the number of cells to be reported.

In this way, the terminal 200 does not report the CQI values for all FAs in the neighboring beam of the serving beam or the CQI reporting beam for the neighboring beam. Instead, the terminal 200 calculates the average value of the highest m CQIs among the CQI measurements for the primary FA and (n-1) secondary FAs, and transmits the calculated average value to the base station 100. Therefore, the m CQI average value means the CQI average value for the highest (m-1) sub FAs and one main FA among the total (n-1) sub FAs received from the base station. This CQI reporting method also reduces the uplink CQI transmission amount.

Figure 6 is a flowchart showing a data transmission method according to the transmission priority of the FA in the base station according to an embodiment of the present invention.

Referring to FIG. 6, the base station 100 creates an activated FA set for the terminal 200 (S602). The terminal 200 is mapped to a specific beam (B1) during the initial access process and establishes a connection with the base station 100 using an FA processor corresponding to the main FA within the beam. The base station 100 causes the terminal 200 to add the remaining FAs, excluding the main FA in the beam, as secondary FAs using an RRC connection reconfiguration message. At this time, the base station 100 may add the main FA to the set of active FAs for the terminal 200.

The base station 100 sets up a radio bearer for the terminal 200 (S604). When setting up a radio bearer, the base station 100 additionally activates a secondary FA to satisfy QoS and adds the activated secondary FA to the active FA set.

Meanwhile, the terminal 200 periodically measures the CQI for the serving beam and neighboring beam of the currently connected serving cell and the CQI for the beams of the neighboring cell, generates CQI reporting data as described in FIG. 5, and reports it to the base station ( 100).

The base station 100 receives CQI report data from the terminal 200 (S606) and determines whether handover is necessary based on the CQI for the serving beam and neighboring beam of the serving cell and the CQI information for the beams of the neighboring cell in the CQI report data. Determine whether beam switching is necessary (S608, S610). The base station 100 determines beam switching when the average CQI value for a specific neighboring beam, that is, the target beam, within the serving cell is greater than or equal to the average value of m CQI values within the set of active FAs within the current serving beam. In addition, the base station 100 determines handover to the specific beam of the neighboring cell when the average CQI value for a specific beam in the neighboring cell, that is, the target beam, is greater than or equal to the average CQI value of m CQIs in the set of active FAs in the current serving beam.

If it is determined that handover is necessary, the base station 100 performs a handover procedure for the terminal 200 using the target beam of the neighboring cell (S612) and sets the activated FA of the terminal 200 for the target beam of the neighboring cell. Reset (S614). At this time, the handover procedure may follow the handover procedure in existing LTE.

Meanwhile, if it is determined that beam switching is necessary, the base station 100 performs the beam switching procedure of the terminal 200 with the target beam of the serving cell (S616), initializes the currently active FA set of the terminal 200 (S618), and ), reset the activated FA set of the terminal 200 for the target beam.

Meanwhile, the base station 100 can change the set of activated FAs of the terminal 200 based on the CQI report value of each FA of the serving cell. FAs with poor CQI reporting values in the activated FA set of the terminal 200 can be removed, and other FAs with good CQI reporting values can be added to the activated FA set. At this time, whether it is good can be determined based on the set CQI threshold.

If there is no need to change the FA in the activated FA set for the terminal 200, the base station 100 uses the CQI report value of each FA included in the activated FA set of the terminal 200 to change the FA in the activated FA set. Determine transmission priority (S622).

The base station 100 schedules data of the radio bearer set for the terminal 200 according to the transmission priority of each FA in the active FA set and transmits it to the terminal 200 (S624).

Meanwhile, if the base station 100 determines that it is necessary to change the FA in the activated FA set for the terminal 200, it performs an FA switching procedure in the activated FA set for the terminal 200 (S626). That is, the base station 100 activates the FA with a good CQI report value among a plurality of FAs based on the CQI report value of each FA of the serving beam through the FA switching procedure, and deactivates the FA with a poor CQI report value to the terminal ( 200) to create a new activated FA set.

The base station 100 generates a MAC CE to activate FAs added to the newly activated FA set for the terminal 200 and to deactivate FAs removed from the newly activated FA set, and transmits the MAC CE to the terminal 200. (S628).

The base station 100 schedules radio bearer data according to the transmission priority of each FA in the existing active FA set and transmits it to the terminal 200 (S630).

Then, the base station 100 updates the existing activated FA set for the terminal 200 with a new activated FA set (S632).

The base station 100 may repeat steps (S608 to S632) based on CQI report data periodically reported from the terminal 200.

Embodiments of the present invention are not only implemented through the devices and/or methods described above, but may also be implemented through a program that realizes the function corresponding to the configuration of the embodiment of the present invention or a recording medium on which the program is recorded. The implementation can be easily implemented by any expert in the technical field to which the present invention belongs based on the description of the embodiments described above.

Although the embodiments of the present invention have been described in detail above, the scope of the present invention is not limited thereto, and various modifications and improvements can be made by those skilled in the art using the basic concept of the present invention defined in the following claims. It falls within the scope of rights.

Claims (17)

A method of determining the transmission priority of the beam element carrier at a base station of a communication system that divides the frequency band of each of the plurality of beams into a plurality of FAs (Frequency Allocation) called beam element carriers,
Receiving CQI report data including CQI information of the serving beam of the serving cell from the terminal,
Based on the CQI information of the serving beam, determining the transmission priority of at least one FA included in the activated FA set of the terminal, and
Scheduling data to be transmitted to the terminal according to the transmission priority of the at least one FA
Includes,
The CQI information of the serving beam includes CQI report values of each of the plurality of FAs,
Among the plurality of FAs, the CQI report value of the main FA includes the entire CQI measurement value, and the CQI report value of each of the remaining secondary FAs excluding the main FA among the plurality of FAs includes the CQI measurement value of the main FA and the corresponding secondary FA. Contains the difference value of the CQI measurements,
The main FA includes a pair of uplink FA and downlink FA and is always active,
A method for determining transmission priority of a beam element carrier in which the secondary FA is activated or deactivated using a medium access control (MAC) control element (CE). In paragraph 1:
The CQI report data further includes CQI information of the neighboring beam of the serving cell and CQI information of beams of the neighboring cell,
Determining handover or beam switching using the CQI information of the CQI report data
It further includes,
The CQI information of the neighboring beam of the serving cell includes the CQI average value of the CQI measurement values of a set number of FAs with high intra-beam CQI measurement values for each beam identifier,
The CQI information of the beams of the neighboring cell includes the average CQI value of the CQI measurement values of a set number of FAs with high CQI measurement values according to each beam identifier for each cell identifier. Method for determining transmission priority of a beam element carrier. In paragraph 2,
The step of determining handover or beam switching is performed when the average CQI value of the neighboring beam within the serving beam is greater than or equal to the CQI average value of the CQI measurements of the set number of FAs within the activated FA set, to the neighboring beam within the serving beam. A method for determining transmission priority of a beam element carrier comprising determining beam switching. In paragraph 3,
The step of determining handover or beam switching further includes performing beam switching to the neighboring beam and then initializing and resetting the activated FA set of the terminal based on the received CQI report data. Transmission of the beam element carrier further includes: How to prioritize. In paragraph 2,
The step of determining the handover or beam switching is performed when the CQI average value of any one beam in the neighboring beam is greater than or equal to the CQI average value of the CQI measurements of the set number of FAs in the activated FA set. A method for determining transmission priority of a beam element carrier, including determining handover with one beam. In paragraph 2,
The set number of FAs includes a primary FA and secondary FAs with high CQI measurements among the maximum number of FAs that the terminal can receive and process. In paragraph 1:
Changing the FA in the activated FA set of the terminal based on the CQI information of the serving beam
A method for determining transmission priority of a beam element carrier further comprising: In paragraph 7:
The steps to change the above are
Determining which FA to activate and which FA to deactivate based on the CQI reporting value of each of the plurality of FAs;
Adding an FA to be activated to the activation FA set, and
Method for determining transmission priority of a beam element carrier, including removing the FA to be deactivated from the activated FA set. In paragraph 8:
The step of changing the transmission priority of the beam element carrier further includes generating a MAC CE to activate FAs added to the activated FA set and deactivating FAs removed from the activated FA set and transmitting them to the terminal. How to decide. A device for determining the transmission priority of the beam element carrier at a base station of a communication system that divides the frequency band of each of the plurality of beams into a plurality of FAs (Frequency Allocation) called beam element carriers, comprising:
A beam mapper that sets the serving beam of the serving cell for the connected terminal, and
Determine the transmission priority of the FAs included in the terminal's activated FA set including FAs activated for transmission using CQI reporting data including CQI information of the serving beam of the serving cell reported from the terminal; , a scheduler that schedules data to be transmitted to the terminal according to the transmission priorities of the FAs
Includes,
The CQI information of the serving beam includes CQI report values of each of the plurality of FAs,
Among the plurality of FAs, the CQI report value of the main FA includes the entire CQI measurement value, and the CQI report value of each of the remaining secondary FAs excluding the main FA among the plurality of FAs includes the CQI measurement value of the main FA and the corresponding secondary FA. Contains the difference value of the CQI measurements,
The main FA includes a pair of uplink FA and downlink FA and is always active,
The secondary FA is a transmission priority determining device for beam element carriers that is activated or deactivated using a medium access control (MAC) control element (CE). delete In paragraph 10:
The CQI report data further includes CQI information of the neighboring beam of the serving cell and CQI information of beams of the neighboring cell,
The CQI information of the neighboring beam of the serving cell includes the CQI average value of the CQI measurement values of a set number of FAs with high intra-beam CQI measurement values for each beam identifier,
The CQI information of the beams of the neighboring cell includes the average CQI value of the CQI measurement values of a set number of FAs with high CQI measurement values according to each beam identifier for each cell identifier. Transmission priority determination device for beam element carriers. In paragraph 12:
The beam mapper is a transmission priority determining device for a beam element carrier that determines handover or beam switching based on the average CQI value of the neighboring beam of the serving cell and the average CQI value of the beams of the neighboring cell. In paragraph 13:
The beam mapper is a beam element that determines beam switching to the neighboring beam in the serving beam if the average CQI value of the neighboring beam of the serving cell is greater than or equal to the CQI average value of the CQI measurements of the set number of FAs in the activated FA set. A device for determining the transmission priority of carrier waves. In paragraph 13:
If the CQI average value of any one beam in the neighboring beam is greater than or equal to the CQI average value of the CQI measurements of the set number of FAs in the activated FA set, the beam mapper performs handover to any one beam in the neighboring beam. A device for determining the transmission priority of beam element carriers.
delete In paragraph 10:
The scheduler determines the FA to be activated and the FA to be deactivated based on the CQI report value of each of the plurality of FAs, adds the FA to be activated to the activated FA set, and removes the FA to be deactivated from the activated FA set. Transmission priority determination device for beam element carriers.

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