KR20210039937A - Method and apparatus for configuring carrier aggregation for serving cells having different start points in a frame in a wireless communication system - Google Patents

Abstract

The present disclosure relates to a communication technique that converges a 5G communication system for supporting a higher data rate after a 4G system with IoT technology, and a system thereof. The present disclosure can be applied to intelligent services (for example, smart home, smart building, smart city, smart car or connected car, healthcare, digital education, retail, security and safety related services, and the like) based on 5G communication technology and IoT-related technology. According to the present disclosure, a base station can set and operate serving cells having different frame start points to a terminal as CA, and thus the terminal can increase a transmission rate.

Description

{Method and apparatus for configuring carrier aggregation for serving cells having different start points in a frame in a wireless communication system}

In an NR system, which is a 5G mobile communication system, it relates to a method of setting serving cells having different frame start times as carrier aggregation (CA).

Efforts are being made to develop an improved 5G communication system or a pre-5G communication system in order to meet the increasing demand for wireless data traffic after the commercialization of 4G communication systems. For this reason, the 5G communication system or the pre-5G communication system is called a communication system after a 4G network (Beyond 4G Network) or a system after an LTE system (Post LTE). In order to achieve a high data rate, the 5G communication system is being considered for implementation in the ultra-high frequency (mmWave) band (eg, such as the 60 Giga (60 GHz) band). In order to mitigate the path loss of radio waves in the ultra-high frequency band and increase the transmission distance of radio waves, 5G communication systems include beamforming, massive MIMO, and Full Dimensional MIMO (FD-MIMO). ), array antenna, analog beam-forming, and large scale antenna technologies are being discussed. In addition, in order to improve the network of the system, in 5G communication system, evolved small cell, advanced small cell, cloud radio access network (cloud RAN), ultra-dense network , Device to Device communication (D2D), wireless backhaul, moving network, cooperative communication, CoMP (Coordinated Multi-Points), and interference cancellation And other technologies are being developed. In addition, in 5G systems, advanced coding modulation (ACM) methods such as Hybrid FSK and QAM Modulation (FQAM) and SWSC (Sliding Window Superposition Coding), advanced access technologies such as Filter Bank Multi Carrier (FBMC), NOMA (non orthogonal multiple access), and sparse code multiple access (SCMA) are being developed.

Meanwhile, the Internet is evolving from a human-centered connection network in which humans create and consume information, to an Internet of Things (IoT) network that exchanges and processes information between distributed components such as objects. IoE (Internet of Everything) technology, which combines IoT technology with big data processing technology through connection with cloud servers, etc., is also emerging. In order to implement IoT, technological elements such as sensing technology, wired/wireless communication and network infrastructure, service interface technology, and security technology are required. , M2M), and MTC (Machine Type Communication) technologies are being studied. In the IoT environment, intelligent IT (Internet Technology) services that create new value in human life by collecting and analyzing data generated from connected objects can be provided. IoT is the field of smart home, smart building, smart city, smart car or connected car, smart grid, healthcare, smart home appliance, advanced medical service, etc. through the convergence and combination of existing IT (information technology) technology and various industries. Can be applied to.

Accordingly, various attempts have been made to apply a 5G communication system to an IoT network. For example, technologies such as sensor network, machine to machine (M2M), and machine type communication (MTC) are implemented by techniques such as beamforming, MIMO, and array antenna, which are 5G communication technologies. will be. The application of a cloud radio access network (cloud RAN) as the big data processing technology described above can be said as an example of the convergence of 5G technology and IoT technology.

Meanwhile, there is a need for a method of configuring carrier aggregation (CA) of serving cells having different frame start times.

A method of configuring serving cells having different frame start times as carrier aggregation (CA) is proposed.

The present invention for solving the above problem is a control signal processing method in a wireless communication system, the method comprising: receiving a first control signal transmitted from a base station; Processing the received first control signal; And transmitting a second control signal generated based on the processing to the base station.

Through the present invention, the base station can operate by setting the serving cells having different frame start times to the terminal as CAs, and accordingly, the terminal can increase the transmission rate.

15A is a diagram illustrating a structure of an LTE system referred to for description of the present invention.
15B is a diagram showing a radio protocol structure of an LTE system referred to for description of the present invention.
15ca and 15cb are diagrams for explaining a carrier aggregation technology (Carrier Aggregation, CA) in a terminal.
15D is a diagram illustrating a discontinuous reception (DRX) operation of a terminal.
15E is a diagram illustrating an operation sequence of a terminal when operating with serving cells having different frame timings set as CA.
15F is a block diagram of a terminal according to an embodiment of the present invention.

Hereinafter, the operating principle of the present invention will be described in detail with reference to the accompanying drawings. In the following description of the present invention, if it is determined that a detailed description of a related known function or configuration may unnecessarily obscure the subject matter of the present invention, a detailed description thereof will be omitted. In addition, terms to be described later are terms defined in consideration of functions in the present invention, which may vary according to the intention or custom of users or operators. Therefore, the definition should be made based on the contents throughout the present specification.

A term for identifying an access node used in the following description, a term for network entities, a term for messages, a term for an interface between network objects, a term for various identification information And the like are illustrated for convenience of description. Accordingly, the present invention is not limited to the terms described below, and other terms referring to objects having an equivalent technical meaning may be used.

For the convenience of description below, the present invention uses terms and names defined in the 3GPP The 3rd Generation Partnership Project Long Term Evolution (LTE) standard, which is the latest standard among currently existing communication standards. However, the present invention is not limited by the terms and names, and may be equally applied to systems conforming to other standards. In particular, the present invention can be applied to 3GPP NR (New Radio: 5th generation mobile communication standard).

15A is a diagram illustrating a structure of an LTE system referred to for description of the present invention.

Referring to FIG. 15A, the wireless communication system includes a plurality of base stations 15a-05, 15a-10, 15a-15, 15a-20, Mobility Management Entity (MME) 15a-20, and S -It is composed of GW (Serving-Gateway)(15a-30). User equipment (UE or terminal) (15a-35) is external through the base station (15a-05) (15a-10) (15a-15) (15a-20) and S-GW (15a-30). Connect to the network.

The base stations 15a-05, 15a-10, 15a-15, and 15a-20 are access nodes of a cellular network and provide wireless access to terminals accessing the network. That is, the base stations 15a-05, 15a-10, 15a-15, and 15a-20 collect status information such as buffer status, available transmission power status, and channel status of terminals to service users' traffic. Thus, the scheduling is performed to support connection between the terminals and the core network (CN). The MME 15a-25 is a device in charge of various control functions as well as a mobility management function for a terminal, and is connected to a plurality of base stations, and the S-GW 15a-30 is a device that provides a data bearer. In addition, the MME (15a-25) and the S-GW (15a-30) can further perform authentication, bearer management, etc. for a terminal accessing the network, and the base station 15a-05 A packet arriving from (15a-10) (15a-15) (15a-20) or a packet to be delivered to the base station (15a-05) (15a-10) (15a-15) (15a-20) is processed.

15B is a diagram showing a radio protocol structure of an LTE system referred to for description of the present invention. The NR to be defined in the future may be partially different from the radio protocol structure in this drawing, but will be described for convenience of description of the present invention.

Referring to Figure 15b, the radio protocol of the LTE system is PDCP (Packet Data Convergence Protocol) (15b-05) (15b-40), RLC (Radio Link Control) (15b-10) (15b-35) in the terminal and the ENB, respectively. ), MAC (Medium Access Control) (15b-15) (15b-30). PDCP (Packet Data Convergence Protocol) (15b-05) (15b-40) is in charge of operations such as IP header compression/restore, and Radio Link Control (hereinafter referred to as RLC) (15b-10) (15b). -35) reconfigures the PDCP Packet Data Unit (PDU) to an appropriate size. The MAC (15b-15) (15b-30) is connected to several RLC layer devices configured in one terminal, and performs an operation of multiplexing the RLC PDUs to the MAC PDU and demultiplexing the RLC PDUs from the MAC PDU. The physical layer (15b-20) (15b-25) channel-codes and modulates upper layer data, converts it into OFDM symbols, and transmits it through a wireless channel, or demodulates and channel-decodes OFDM symbols received through the radio channel to the upper layer. It does the act of delivering. In addition, the physical layer also uses HARQ (Hybrid ARQ) for additional error correction, and the receiving end transmits whether or not a packet transmitted from the transmitting end is received in 1 bit. This is called HARQ ACK/NACK information. Downlink HARQ ACK/NACK information for uplink transmission is transmitted through a PHICH (Physical Hybrid-ARQ Indicator Channel) physical channel, and uplink HARQ ACK/NACK information for downlink transmission is PUCCH (Physical Uplink Control Channel) or PUSCH. (Physical Uplink Shared Channel) It can be transmitted through a physical channel. The PUCCH is used for the UE to transmit not only the HARQ ACK/NACK information, but also downlink channel status information (CSI, Channel Status Information), scheduling request (SR, Scheduling Request), and the like to the base station. The SR is 1-bit information, and when a terminal transmits an SR to a resource in a PUCCH set by a base station, the base station recognizes that there is data to be transmitted by the corresponding terminal in an uplink, and allocates an uplink resource. The UE may transmit a detailed buffer status report (BSR) message through the uplink resource. The base station can allocate a plurality of SR resources to one terminal.

Meanwhile, the PHY layer may consist of one or a plurality of frequencies/carriers, and a technology in which a plurality of frequencies are simultaneously set and used by one base station is referred to as a carrier aggregation technology (carrier aggreagation, hereinafter referred to as CA). CA technology refers to the use of only one carrier for communication between a terminal (or user equipment, UE) and a base station (E-UTRAN NodeB, eNB), and a subcarrier by additionally using a primary carrier and one or a plurality of subcarriers. The amount of transmission can be dramatically increased by the number of. Meanwhile, in LTE, a cell in a base station using a primary carrier is called a PCell (Primary Cell), and a subcarrier is called a SCell (Secondary Cell). A technology in which the CA function is extended to two base stations is referred to as dual connectivity technology (hereinafter referred to as DC). In the DC technology, a terminal is using a primary base station (Master E-UTRAN NodeB, hereinafter referred to as MeNB) and a secondary base station (Secondary E-UTRAN NodeB, hereinafter referred to as SeNB) simultaneously and used, and cells belonging to the primary base station are used as primary cells. A group (Master Cell Group, hereinafter referred to as MCG), and cells belonging to an auxiliary base station are referred to as a Secondary Cell Group (hereinafter referred to as SCG). There is a representative cell for each cell group, and the representative cell of the primary cell group is referred to as a primary cell (hereinafter referred to as a PCell), and the representative cell of the auxiliary cell group is referred to as a primary secondary cell (hereinafter referred to as a PSCell). do. When using the aforementioned NR, the MCG is used as LTE technology and the SCG is used as the NR, so that the UE can use both LTE and NR at the same time. This is called EN-DC (E-UTRA-NR Dual Connectivity). Conversely, a scenario in which the MCG is used as an NR technology and the SCG is used as an LTE technology may be considered, which is referred to as NE-DC (NR-E-UTRA Dual Connectivity). Also, the technology that both MCG and SCG use as NR technology is called NR-DC (NR-NR Dual Connectivity).

Although not shown in this figure, there is an RRC (Radio Resource Control, hereinafter referred to as RRC) layer, respectively, above the PDCP layer of the terminal and the base station, and the RRC layer transmits access and measurement-related configuration control messages for radio resource control. You can give and take. For example, measurement may be instructed to the UE using the message of the RRC layer, and the UE may report the measurement result to the base station using the message of the RRC layer.

Meanwhile, the transmission units of the PCell and the SCell may be the same or different. For example, in LTE, the transmission unit of both the PCell and the SCell may be the same in units of 1 ms, but in the NR, the transmission unit in the PCell is 1 ms, but the transmission unit in the SCell may have a length of 0.5 ms.

Table 1 below shows information on the length of a slot available in each serving cell (i.e., PCell or SCell) according to the numerology used for each serving cell in the NR (or according to the subcarrier spacing). .

[Table 1]

In addition, the following units are used in the frame structure in the radio section (ie, between the base station and the terminal) in LTE and NR.

- Radio Frame: It has a length of 10 ms and is identified by a system frame number (SFN) for each radio frame.

- Subframe: It has a length of 1 ms, and there are 10 subframes in the radio frame. Identified by subframe numbers 0-9 within every radio frame

- Slot: As shown in the table, it has a length according to a set value, and a transmission unit when the base station and the terminal transmit data.

15ca and 15b are diagrams for explaining a carrier aggregation technology (Carrier Aggregation, CA) in a terminal.

15ca and 15b, in one base station, multiple carriers may be transmitted and received over several frequency bands in general. For example, when a carrier 15c-15 having a center frequency f1 and a carrier having a center frequency f3 (15c-10) are transmitted from the base station 15c-05, conventionally, one terminal is one of the two carriers. Data was transmitted/received using the carrier of. However, a terminal with carrier aggregation capability can transmit and receive data from multiple carriers at the same time. The base station 15c-05 can increase the transmission speed of the terminal 15c-30 by allocating more carriers to the terminal 15c-30 having the carrier aggregation capability according to the situation.

In the traditional sense, when one forward carrier and one reverse carrier transmitted and received from one base station constitute one cell, carrier aggregation may be understood as a terminal transmitting and receiving data through multiple cells at the same time. will be. Through this, the maximum transmission rate is increased in proportion to the number of accumulated carriers (or the number of serving cells).

In the following description of the present invention, the fact that the terminal receives data through an arbitrary forward carrier or transmits data through an arbitrary reverse carrier means that a control channel provided by a cell corresponding to a center frequency and a frequency band characterizing the carrier and It has the same meaning as transmitting and receiving data using a data channel.

Meanwhile, for CA configuration (or for handover to a neighboring base station, etc.), the terminal may receive the measurement configuration to report the result of measuring the neighboring cell from the base station. Through this, the terminal may perform measurement according to the measurement configuration received from the base station, and report the performed measurement result to the base station. The measurement configuration includes detailed information on which frequency the measurement is reported under what condition, and additionally, information on whether the terminal measures another frequency at which measurement gap (Measurement Gap) may be included. Accordingly, when the measurement interval is set for the terminal, the terminal may receive a periodic measurement interval according to the set information. Accordingly, in order to measure the frequencies for which the measurement is set at a corresponding measurement interval, the terminal does not perform the following operation with the current base station (or in the serving cell(s) using a frequency related to the measurement).

- PUCCH transmission (HARQ ACK/NACK, SR, CSI)

- SRS transmission

- PDCCH monitoring and data reception. However, if it is necessary to perform RAR reception or check whether Msg3 transmission is successful, perform PDCCH monitoring and data reception.

- Data transmission. However, when random access is being performed, Msg3 transmission of random access must be performed.

In addition, the terminal may perform data transmission/reception with the base station in a section other than the above measurement interval. In NR, when the operating frequency is 410 MHz-7125 MHz (based on Rel-15, which is the version information of NR), it is called FR1 (frequency range 1), and when the operating frequency is 24250 MHz-52600 MHz, it is called FR2 (frequency range 2). It is called. Accordingly, when the measurement interval is for FR1 measurement, the UE does not perform the above operation in the serving cell(s) using the FR1 frequency, and the UE is still in the serving cell(s) using the FR2 frequency. You can perform the operation. In addition, for example, when the measurement interval is for FR2 measurement, the UE does not perform the above operation in the serving cell(s) using the FR2 frequency, and still in the serving cell(s) using the FR1 frequency. The above operation can be performed. If the measurement interval is not limited to FR1 and FR2 and is set to the entire terminal, the terminal does not perform the above operation during the measurement interval in all serving cell(s).

Meanwhile, the measurement interval has a periodic measurement interval as described above, which starts with the SFN of a specific cell among the base stations and has a periodic measurement interval. This is because, as described above, since the terminal does not perform the above operations during the measurement interval, the terminal and the base station must have the same understanding of the measurement interval. Meanwhile, MCG and SCG may use different SFNs. In addition, it is possible to assume a scenario in which FR1 and FR2 use different SFNs within the MCG or within the SCG. In this case, the base station may implicitly or explicitly instruct the UE to set the measurement interval based on the SFN of which cell.

For example, in the case of the above-described EN-DC, without a separate explicit indicator, the base station and the terminal may implicitly determine a reference cell for the measurement interval. For example, in the case of the measurement interval for FR1, the UE can determine the starting point and period of the measurement interval based on the SFN and subframe boundary of the PCell, and in the case of the measurement interval for FR2, in FR2 of (NR SCG) The start point and period of the measurement interval may be determined based on the SFN and the subframe boundary of one of the operating serving cells.

On the other hand, in the case of NE-DC or NR-DC, when setting the measurement interval to the terminal, the base station may indicate which SFN of the serving cell is to be used as an explicit indicator. As the explicit indicator, a field such as refServCellIndicator may be used, and the refServCellIndicator may indicate one of pCell, pSCell, and mcg-FR2, so serving using FR2 among PCell or PSCell or MCG serving cells It can be instructed to be based on one serving cell among the cells. In addition, a scenario in which the refServCellIndicator is further extended may be considered in consideration of scenarios in which the MCG uses FR1 and FR2 in the MCG and the SCG uses FR1 and FR2 in the future in the NR-DC. For this, the refServCellIndicatorExt is introduced. It can be added to indicate scg-FR2. Alternatively, in order to set the measurement interval based on the SFN and subframe boundary of a specific serving cell in the MCG or SCG, a scenario in which an identifier (ServCellIndex) of a serving cell is additionally indicated as a refServCellIndicator may be considered. In this case, a field such as refServCellIndicatorFR2, which is another extended version of refServCellIndicator, is newly defined (in consideration of the case where the main scenario is FR2), and the corresponding field can be defined to indicate the identifier of the serving cell. Through this, when the measurement interval is set, the terminal may determine which of the serving cell SFN and subframe boundaries to set the measurement interval based on.

Meanwhile, when using CA technology in an NR system, frequency division duplexing (FDD) for each serving cell: transmits downlink and uplink using different frequencies) or time division duplexing (TDD) : Transmission by dividing downlink and uplink in time at the same frequency) can be selectively used according to the situation of the base station and the operator.

Specifically, as shown in Fig. 15Cb, when TDD technology is used adjacent to each other in frequency (for example, (15c-71) and (15c-73); or (15c-75) (15c-77)) TDD The pattern (distribution setting of downlink (D) and uplink (U)) should be used in the same manner. If the downlink time point and the uplink time point at adjacent frequencies overlap, the downlink signal of the base station (transmitting the Sen signal) interferes with the uplink of the adjacent frequency. Communication can be difficult. To this end, as described in this figure, the TDD pattern between the operator A and the operator B is the same (for example, (15c-71) and (15c-73)), and the TDD pattern between the operator A and the operator C is the same. Shown (e.g., (15c-75) and (15c-77)). Meanwhile, in this example, operator A may consider a scenario in which two carriers (15c-73) (15c-75) are intended to be used as CAs. At this time, since the desired TDD pattern was used without separate agreement between the operators B and C, the pattern between the two carriers 15c-73 and 15c-75 may be different from the point of view of the operator A.

Meanwhile, in the NR system, when configuring the TDD pattern to the terminal, the format of the pattern may be set from the downlink as follows.

For example, in the case of the pattern of operator B, pattern 1 has 3 DLs (15c-81) and 2 ULs (15c-83), and 2 DLs (15c-85) and 3 ULs (15- It is a repetitive pattern of pattern 2 with slots of 76). In addition, the pattern of operator C is a repetitive pattern of pattern 1 having 4 DL and 1 UL slot, and pattern 2 having 3 DL and 2 UL slots.

Table 2 below is a message format used by the base station to set the TDD pattern for each serving cell to the terminal in the NR system. For example, it is an existing TDD pattern message format. According to this, it is located in the order of (15c-50) (15c-60), downlink slots (nrofDownlinkSlots), and downlink symbols (nrofDownlinkSymbols) from the start of the frame, starting from the last position of the pattern, backwards, uplink TDD patterns are set in the order of slots (nrofUplinkSlots) and uplink symbols (nrofUplinkSymbols). That is, accordingly, the overall order is defined as downlink slots (nrofDownlinkSlots), downlink symbols (nrofDownlinkSymbols), uplink symbols (nrofUplinkSymbols), and uplink slots (nrofUplinkSlots).

[Table 2]

According to the format shown in Table 2 above, if the operator A wants to set the (15c-75) serving cell as the PCell to the terminal as the (15c-73) serving cell as the SCell, the current signaling structure is upstreamed. There is a problem in that the TDD pattern for the (15c-73) serving cell starting from the link slot cannot be set.

To solve this problem, a method of changing the TDD configuration method may be considered. For example, by adding a patternOffset to a message set by the base station to the terminal as follows, a slot according to the aforementioned subcarrier spacing according to referenceSubcarrierSpacing additionally signals an offset. For example, accordingly, for (15c-73) of FIG. 15C, the patternOffset is signaled as 2 slots, thereby indicating that the pattern itself should be moved by 2 slots. The unit of the patternOffset is a slot unit in this example, but a symbol unit or a subframe unit may be used.

Table 3 below is an example 1 of a new TDD pattern message format.

[Table 3]

In another embodiment, when offset as described above, for a case where the uplink slot is first located, the number of uplink slots (nrofStartingUplinkSlots) existing from the start point of the corresponding SCell based on the PCell is determined. You can also consider how to notify. The message format showing this is shown in Table 4.

For example, Table 4 is Example 2 of a new TDD pattern message format.

[Table 4]

Another embodiment is a method of adding 1-bit information (reverse) to create a new pattern starting from an uplink slot rather than a downlink slot. Specifically, when the reverse field is included, the above-described downlink slots (nrofDownlinkSlots), downlink symbols (nrofDownlinkSymbols), uplink symbols (nrofUplinkSymbols), and uplink slots (nrofUplinkSlots), not in the order of, uplink slot ( This is a method of changing the order of nrofDownlinkSlots), uplink symbols (nrofDownlinkSymbols), downlink symbols (nrofUplinkSymbols), and downlink slots (nrofUplinkSlots).

For example, Table 5 is Example 3 of a new TDD pattern message format.

[Table 5]

In the above example, methods for setting a new TDD pattern for each serving cell so as not to affect other existing operations (collectively referred to as method A) have been described. However, as another embodiment, a method of assigning a slot number differently for each serving cell (Scheme B) may be considered. For example, according to the above example, the slot numbers of the PCell and the SCell at the same time point are all the same. However, as shown in FIG. 15C, if there is a difference by 2 slots, the slot number may be assigned differently for each serving cell as the SFN start point is different. For example, the slot number of the carrier of (15c-75) is 0, 1, 2, ... In the case of increasing as, [Max. slot number per frame-2], [Max slot number per frame-1], 0, 1, 2,… for the carrier of (15c-73). Likewise, it may be possible to consider using a slot number that differs by 2 at the same time point. For example, for each SCell, a slot number is assigned for each serving cell by using an SFN/slot number corrected by a slot offset signaled for each SCell in addition to the TDD pattern information set for each corresponding SCell. The slot offset in the scheme B is also determined in a slot unit according to the subcarrier spacing of the SCell, as in the first embodiment of the scheme A, and the number of slots from 0 to N or -N/2 to N/2 (N Is an integer and may have a value of, for example, the maximum number of slots in one frame. Accordingly, the terminal may determine that slot 0 of the SCell starts at a point separated by a slot length * slot offset corresponding to the SCS of the SCell based on slot 0 of the PCell. Alternatively, the terminal may determine that slot 0 of the SCell starts at a point separated by a slot length * slot offset corresponding to the subcarrier interval of the PCell. In this way, in the case of the method B, various operations using the slot number may be affected.

For example, in the case of DRX, which will be described later, it is necessary to determine which slot number is used as the reference point of the SFN at which the DRX cycle is assigned, and as an example, based on the SFN of the PCell and slot number 0. You can decide to make a decision.

In addition, in order not to transmit the physical downlink control channel (Physical Downlink Control Channel, hereinafter referred to as PDCCH) used to transmit downlink and uplink scheduling information for periodic allocation, the'configured uplink' ( In the case of configured uplink grant), there are two types, and in the case of Type1, both the start time and period are set in the RRC layer, and in the case of Type 2, only the period is set in the RRC layer, and then through the PDCCH message. This is a method of'activating' the configured uplink. (Once activated, the uplink can be transmitted according to the cycle set by RRC without PDCCH from thereafter.) In this case, since the start time is set in Type 1, a problem arises as to which criterion to interpret the slot number. Accordingly, the configured uplink of the PCell is determined based on the SFN or slot number or symbol number of the PCell, and the configured uplink of the SCell starts based on the PCell if no additional slot offset is set, and the slot offset is the corresponding SCell. If set for, it should be defined to start based on the adjusted SFN/slot number.

In addition, in the case of an operation of activating the SCell set as a message of the RRC layer to actually use and deactivating afterwards, activation and deactivation of a specific SCell can be indicated with the MAC Control Element (CE), which is a control message of the MAC layer Activation/Deactivation MAC CE), since the terminal receiving the same cannot immediately activate and deactivate, when the MAC CE is received in n slots, the corresponding operation is performed in n + k slots. At this time, if the slot number is different as in the scheme B, the starting point needs to be adjusted as well, and summarized in Table 6 below.

[Table 6]

In some cases, regardless of the cell receiving the MAC CE and the cell to be activated, it may be unconditionally activated at the time n+k based on the time point of the PCell.

Meanwhile, FIG. 15D is a diagram for explaining a discontinuous reception (hereinafter referred to as DRX) operation of the above-described terminal.

DRX is instead of monitoring all physical downlink control channels (Physical Downlink Control Channel, hereinafter referred to as PDCCH) in order to obtain scheduling information according to the settings of the base station in order to minimize power consumption of the terminal. It is a technology that monitors only the PDCCH of. The basic DRX operation has a DRX cycle (15d-00), and the PDCCH is monitored only during the onDuration (15d-05) time. In the connected mode, the DRX cycle has two values: long DRX and short DRX. In general, a long DRX cycle is applied, and if necessary, the base station can additionally set a short DRX cycle. If both the long DRX cycle and the short DRX cycle are set, the terminal starts the short DRX timer and repeats from the short DRX cycle. If there is no new traffic until after the short DRX timer expires, the terminal is long in the short DRX cycle. Change to DRX cycle. If, during the on-duration (15d-05) time, scheduling information for a new packet is received by the PDCCH (15d-10), the UE starts the DRX inactivity timer (15d-15). The terminal maintains the active state during the DRX inactivity timer. For example, the UE continues to monitor the PDCCH. In addition, the terminal also starts the HARQ RTT timer (15d-20). The HARQ RTT timer may be applied to prevent the UE from unnecessarily monitoring the PDCCH during the HARQ Round Trip Time (RTT) time. Therefore, during the timer operation time, the UE does not need to perform PDCCH monitoring. However, while the DRX inactivity timer and HARQ RTT timer operate at the same time, the terminal continues to monitor the PDCCH based on the DRX inactivity timer. When the HARQ RTT timer expires, the DRX retransmission timer (15d-25) starts. While the DRX retransmission timer is operating, the UE must perform PDCCH monitoring. In general, during the DRX retransmission timer operation time, scheduling information for HARQ retransmission is received (15d-30). Upon receiving the scheduling information, the UE immediately stops the DRX retransmission timer and starts the HARQ RTT timer again. The operation continues until the packet is successfully received (15d-35).

15E is a flowchart illustrating a sequence of operations of a terminal when operating by setting serving cells having different frame timings as CAs.

In the above flowchart, it is assumed that the terminal is in a connection mode (RRC_CONNECTED) state in which data transmission/reception is possible by establishing a connection to the base station (15e-01).

Thereafter, the terminal may report to the base station what capability the terminal has to the base station (15e-03). In the capability information of the UE, it may be reported that the UE may have different frame start points as described in FIG. 15C. This may be a capability available in all frequency bands supported by the UE, or may be a capability only available in a specific frequency band. In the former case, the corresponding capability can be transmitted in 1 bit in the capability information of the terminal, but in the latter case, it is possible to report whether or not a different frame start point can be obtained for each band or a combination of each band.

Thereafter, the UE may receive an RRCReconfiguration message of the RRC layer from the base station (15e-05). The RRCReconfiguration message may be used when setting various configuration information to the terminal. For example, when the SCell is added to additionally use, as described above, configuration information related thereto may be included. Configuration information such as a slot offset required for the above-described scheme A and scheme B may be included in the message of the RRC layer. When describing the method A, various message formats are information included in the RRCReconfiguration message.

According to the above information, if method A is used (15e-07), the UE applies the same slot number and SFN as the PCell when calculating the above-described DRX, configured uplink allocation information, and SCell activation and deactivation time. You can do it.

However, if the method B is used (15e-07), the operation can be performed by applying the SFN and the slot number corrected by the slot offset as described in FIG. 15C with respect to the configuration information of the corresponding SCell ( 15e-13).

In addition, a scenario in which the above-described measurement interval is set through the RRCReconfiguration message may be considered. In more detail, the following parameters related to the measurement interval may be set from the base station.

- Type of gap (e.g. gapUE, gapFR1, gapFR2)

- Measurement interval start point and period information within the gap type

- Reference indicator of the measurement interval (refServCellIndicator or refServCellIndicatorExt)

At this time, if the above-described scheme B is used, the SFN and subframe boundaries are determined by using one of several serving cells using FR2 such as mcg-FR2 and scg-FR2. The SFN starting point can be different. To this end, the UE may select one serving cell among cells whose SFN is not corrected by a slot offset among corresponding serving cells (eg, among serving cells using FR2) to determine the location of the measurement interval. Alternatively, as described above, when the measurement interval is set from the base station, a specific serving cell identifier (ServCellIndex) is instructed, and the terminal may determine the measurement interval based on the SFN and subframe boundary of the corresponding serving cell. Through this, even if the SFN is different for each serving cell, the UE has a specific serving cell (e.g., a PCell or PSCell or a serving cell to which slot offset is not applied in mcg-FR2/scg-FR2, or a specific serving cell indicated by the base station) By determining the measurement interval based on, it is possible to measure neighboring cells during the measurement interval at the same timing as the base station.

To describe the above in more detail, if the gap type set from the base station is gapFR2, if either refServCellIndicator or refServCellIndicatorExt is set, if the setting is PCell or PSCell, the UE uses the cell as a reference cell of the measurement interval. . However, in the case of mcg-FR2 or scg-FR2, if the method B is used, the UE uses one of the serving cells to which the offset is not applied among the serving cells using FR2 as a reference cell of the measurement interval. Alternatively, as another method, the terminal may use a serving cell having the lowest ServCellIndex among corresponding serving cells. Alternatively, as described above, receiving a specific ServCellIndex (having a unique value across the entire MCG and SCG) from the base station, the terminal uses the indicated serving cell as a reference cell of the measurement interval.

If the gap type set from the base station is gapFR2, and none of refServCellIndicator and refServCellIndicatorExt is set, among the FR2 serving cells, a predetermined condition is satisfied (e.g., slot offset is not set, or the lowest ServCellIndex is set. The terminal) uses the serving cell as a reference cell of the measurement interval.

If the gap type set by the base station is gapFR1 or gapUE, the UE uses the indicated serving cell among PCell or PSCell if refServCellIndicator is set, and always uses PCell as the reference cell of the measurement interval if refServCellIndicator is not set. .

Or, if the gap type set from the base station is gapFR1 or gapUE, the base station sets a parameter such as a separate refServCellIndicatorExtFR1 to indicate one of the SCells using the FR1 to be used and is specific to the terminal (using FR1). SCell can be set as the reference cell of the measurement interval. This is because even if the CA is set using only the FR1 used by the base station, the subcarrier spacing (SCS) used within the CA may be different (eg, 15 kHz for PCell and 30 kHz for SCell). For example, in the above example, since the time slot interval of the SCell is shorter (1 slot for PCell is 1 ms, and 1 slot for SCell is 0.5 ms), the reference cell of the measurement interval is set based on the SCell indicated by refServCellIndicatorExtFR1. Thus, the base station can further set the measurement interval for the FR1 to the terminal.

In addition, after (or by the above RRCReconfiguration message), the terminal can receive the DRX configuration from the base station. The DRX configuration includes timers required for driving the DRX, and each timer and a time unit of each timer are as follows.

- onDuration timer: set to the number of slots of the reference cell

- short DRX cycle: Set as the number of slots of the reference cell (or set as the number of subframes)

- short DRX cycle timer: set to the number of slots of the reference cell

- long DRX cycler: Set as the number of slots of the reference cell (or set as the number of subframes)

- DRX inactivity timer: set to the number of slots of the reference cell

- HARQ RTT timer: set to the number of slots of the cell in which transmission/retransmission is performed

- DRX retransmission timer: Set to the number of slots in the cell in which transmission/retransmission is performed

The reference cell slot may be a slot of a PCell, or a slot of a cell having the longest transmission unit among all serving cells (ie, PCell and SCell).

Accordingly, the UE repeats the cycle according to the set cycle, and can monitor the PDCCH during onDuration. If there is new data transmission in onDuration, the DRX inactivity timer may be driven at the time when onDuration ends, and the HARQ RTT timer may be driven at the time when the new data transmission is received. If the terminal receives new data transmission in the above-described active time period, the terminal may perform the above operation. In addition, when the packet is not successfully received until the HARQ RTT timer expires, the UE drives the DRX retransmission timer to monitor the PDCCH for retransmission from the base station. If the packet is successfully received until the HARQ RTT timer expires, the UE no longer drives the DRX retransmission timer. As described above, when both the Long DRX cycle and the short DRX cycle are set, the UE starts the short DRX timer and repeats from the short DRX cycle. If there is no new traffic until after the short DRX timer expires, the UE is short Change from DRX cycle to long DRX cycle. Thereafter, when new traffic occurs, the UE may use a short DRX cycle again and repeat the above procedure (15e-05).

15F is a block diagram of a terminal according to an embodiment of the present invention.

Referring to FIG. 15F, the terminal includes a radio frequency (RF) processing unit 15f-10, a baseband processing unit 15f-20, a storage unit 15f-30, and a control unit 15f-40. can do.

The RF processing unit 15f-10 may perform a function of transmitting and receiving a signal through a wireless channel, such as band conversion and amplification of a signal. For example, the RF processing unit (15f-10) up-converts the baseband signal provided from the baseband processing unit (15f-20) to an RF band signal, and then transmits it through an antenna, and RF received through the antenna. The band signal can be downconverted to a baseband signal. The RF processing unit 15f-10 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), and the like. In FIG. 15F, only one antenna is shown, but the terminal may include a plurality of antennas. In addition, the RF processing unit 15f-10 may include a plurality of RF chains. Furthermore, the RF processing unit 15f-10 may perform beamforming. For the beamforming, the RF processing unit 15f-10 may adjust a phase and a magnitude of each of signals transmitted/received through a plurality of antennas or antenna elements.

The baseband processing unit 15f-20 may perform a function of converting between a baseband signal and a bit stream according to a physical layer standard of a system. For example, when transmitting data, the baseband processing unit 15f-20 may generate complex symbols by encoding and modulating a transmission bit stream. In addition, when receiving data, the baseband processing unit 15f-20 may restore a received bit stream through demodulation and decoding of the baseband signal provided from the RF processing unit 15f-10. For example, in the case of the OFDM (orthogonal frequency division multiplexing) method, when transmitting data, the baseband processor 15f-20 generates complex symbols by encoding and modulating a transmission bit stream, and subcarriers the complex symbols. After mapping to, OFDM symbols may be configured through an inverse fast Fourier transform (IFFT) operation and a cyclic prefix (CP) insertion. In addition, when receiving data, the baseband processing unit 15f-20 divides the baseband signal provided from the RF processing unit 15f-10 in units of OFDM symbols, and applies a fast Fourier transform (FFT) operation to subcarriers. After restoring the mapped signals, a received bit stream may be restored through demodulation and decoding.

The baseband processing unit 15f-20 and the RF processing unit 15f-10 may transmit and receive signals as described above. Accordingly, the baseband processing unit 15f-20 and the RF processing unit 15f-10 may be referred to as a transmission unit, a reception unit, a transmission/reception unit, or a communication unit. In addition, at least one of the baseband processing unit 15f-20 and the RF processing unit 15f-10 may include different communication modules to process signals of different frequency bands. The different frequency bands may include a super high frequency (SHF) (eg, 2.5GHz, 5Ghz) band, and a millimeter wave (eg, 60GHz) band.

The storage unit 15f-30 may store data such as a basic program, an application program, and setting information for the operation of the terminal.

The controller 15f-40 may control overall operations of the terminal. For example, the control unit 15f-40 transmits and receives signals through the baseband processing unit 15f-20 and the RF processing unit 15f-10. In addition, the control unit 15f-40 writes and reads data in the storage unit 15f-40. To this end, the control unit 15f-40 may include at least one processor. For example, the control unit 15f-40 may include a communication processor (CP) that controls communication and an application processor (AP) that controls an upper layer such as an application program. According to an embodiment of the present invention, the control unit 15f-40 includes a multiple connection processing unit 15f-42 that performs processing for operating in a multiple connection mode. For example, the controller 15f-40 may control the terminal to perform a procedure shown in the operation of the terminal shown in FIG. 15F.

According to an embodiment of the present invention, when a slot offset is set from a base station, the UE may perform reception and transmission by determining a downlink and an uplink slot accordingly.

The methods according to the embodiments described in the claims or the specification of the present invention may be implemented in the form of hardware, software, or a combination of hardware and software.

When implemented in software, a computer-readable storage medium storing one or more programs (software modules) may be provided. One or more programs stored in a computer-readable storage medium are configured to be executable by one or more processors in an electronic device (device). The one or more programs include instructions that cause the electronic device to execute methods according to the embodiments described in the claims or specification of the present invention.

These programs (software modules, software) include random access memory, non-volatile memory including flash memory, read only memory (ROM), and electrically erasable programmable ROM. (EEPROM: Electrically Erasable Programmable Read Only Memory), magnetic disc storage device, Compact Disc-ROM (CD-ROM), Digital Versatile Discs (DVDs), or other types of It may be stored in an optical storage device or a magnetic cassette. Alternatively, it may be stored in a memory composed of a combination of some or all of them. In addition, a plurality of configuration memories may be included.

In addition, the program is through a communication network composed of a communication network such as the Internet, an intranet, a local area network (LAN), a wide LAN (WLAN), or a storage area network (SAN), or a combination thereof. It may be stored in an accessible storage device. Such a storage device can access a device performing an embodiment of the present invention through an external port. In addition, a separate storage device on the communication network may access a device performing an embodiment of the present invention.

In the specific embodiments of the present invention described above, constituent elements included in the invention are expressed in the singular or plural according to the presented specific embodiment. However, the singular or plural expression is selected appropriately for the situation presented for convenience of description, and the present invention is not limited to the singular or plural constituent elements, and even constituent elements expressed in plural are composed of the singular or singular. Even the expressed constituent elements may be composed of pluralities.

Meanwhile, although specific embodiments have been described in the detailed description of the present invention, various modifications are possible without departing from the scope of the present invention. Therefore, the scope of the present invention is limited to the described embodiments and should not be determined, and should be determined by the scope of the claims and equivalents as well as the scope of the claims to be described later.

15f-10: RF (Radio Frequency) processing unit
15f-20: baseband processing unit
15f-30: storage
15f-40: control unit

Claims (1)

In the control signal processing method in a wireless communication system,
Receiving a first control signal transmitted from a base station;
Processing the received first control signal; And
And transmitting a second control signal generated based on the processing to the base station.

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