KR102258129B1 - Method and apparatus to efficiently provide TDD configuration to terminal in the mobile communication system - Google Patents

Abstract

A method of configuring a time division duplex (TDD) of a terminal in a communication system according to an embodiment of the present invention includes: receiving a first TDD configuration from a base station; Receiving a message including dynamic TDD configuration related information from the base station; Receiving a second TDD configuration according to the received dynamic TDD configuration related information; Receiving an uplink grant from the base station; And determining to apply the first TDD setting or the second TDD setting based on a method in which the reverse grant is received. According to an embodiment of the present invention, when TDD is set in a terminal supporting TDD in a wireless communication system, it is possible to set the TDD in a shorter period, and it is possible to variably and quickly set the TDD in the terminal according to the communication situation.

Description

[Method and apparatus to efficiently provide TDD configuration to terminal in the mobile communication system]

The present invention relates to a method and apparatus for effectively providing TDD configuration information to a terminal and determining an uplink transmission timing in a mobile communication system supporting TDD.

In general, mobile communication systems have been developed for the purpose of providing communication while securing user mobility. These mobile communication systems have reached the stage of providing high-speed data communication services as well as voice communication thanks to the rapid development of technology.

In recent years, as one of the next-generation mobile communication systems, standard work for LTE-A (Long Term Evolution Advanced) is in progress in 3GPP. LTE-A is a technology that implements high-speed packet-based communication with a transmission rate of up to 100 Mbps, which is higher than the currently provided data rate, with the target of commercialization around 2012. To this end, various methods are being discussed, for example, a method of reducing the number of nodes located on a communication path by simplifying the structure of a network, or a method of making wireless protocols as close to a wireless channel as possible.

Meanwhile, in the data service, unlike the voice service, resources that can be allocated are determined according to the amount of data to be transmitted and the channel condition. Accordingly, in a wireless communication system such as a mobile communication system, management such as allocating transmission resources in consideration of the amount of resources to be transmitted by the scheduler, the condition of the channel, and the amount of data is performed. This is the same in LTE, one of the next-generation mobile communication systems, and a scheduler located at the base station manages and allocates radio transmission resources.

Recently, discussions on an evolved LTE communication system (LTE-Advanced, LTE-A) that improve the transmission speed by incorporating various new technologies into the LTE communication system are in earnest. IMTA (Interference Mitigation and Traffic adaptation) technology is one of several technologies under study in LTE-A. IMTA technology is a technology applied to TDD, which has a short cycle for the purpose of controlling the amount of traffic and interference occurring in the uplink and downlink, and changes the ratio of the amount of resources allocated to the uplink and downlink. In order to efficiently implement such IMTA technology, the LTE-A system needs to be improved in various ways.

The present invention has been proposed to solve the above-described problem, and a base station and a terminal for variably setting TDD to a terminal in a wireless communication system supporting time division duplex (TDD), and a method of operating the base station and the terminal The purpose is to present.

In order to achieve the above-described problem, a method for configuring a time division duplex (TDD) of a terminal in a communication system according to an embodiment of the present invention includes: receiving a first TDD configuration from a base station; Receiving a message including dynamic TDD configuration related information from the base station; Receiving a second TDD configuration according to the received dynamic TDD configuration related information; Receiving an uplink grant from the base station; And determining to apply the first TDD setting or the second TDD setting based on a method in which the reverse grant is received.

In a communication system according to another embodiment of the present invention, a terminal for setting time division duplex (TDD) receives a first TDD configuration from a base station, receives a message including dynamic TDD configuration related information from the base station, and , A transmission/reception unit receiving a second TDD configuration according to the received dynamic TDD configuration-related information and receiving an uplink grant from the base station, and the first TDD configuration based on a method in which the uplink grant is received, or And a control unit that determines to apply the second TDD setting.

A method of configuring a time division duplex (TDD) of a base station in a communication system according to another embodiment of the present invention includes: transmitting a first TDD configuration to a terminal; Receiving a message including whether or not TDD can be configured from the terminal; Determining whether to set a dynamic TDD operation based on the received message; Transmitting a message including information related to dynamic TDD configuration to the terminal according to the determination result; Transmitting a second TDD configuration according to the transmitted dynamic TDD configuration related information; And transmitting a reverse grant according to the first TDD setting or the second TDD setting, wherein the terminal applies the first TDD setting or the second TDD setting based on a method in which the reverse grant is received. Characterized in that.

In a communication system according to another embodiment of the present invention, a base station for setting a time division duplex (TDD) of a terminal transmits a first TDD configuration to the terminal, and a message including whether or not TDD can be configured from the terminal A transmission/reception unit receiving And a control unit for determining whether to set a dynamic TDD operation based on the received message, wherein the transmission/reception unit transmits a second TDD configuration according to the transmitted dynamic TDD configuration related information, and transmits the first TDD configuration or the first TDD configuration. 2 A reverse grant is transmitted according to a TDD setting, and the terminal applies the first TDD setting or the second TDD setting based on a method in which the reverse grant is received.

According to an embodiment of the present invention, when TDD is set in a terminal supporting TDD in a wireless communication system, it is possible to set the TDD in a shorter period, and it is possible to variably and quickly set the TDD in the terminal according to the communication situation.

1 is a diagram showing a structure of an LTE system to which the present invention is applied,
2 is a diagram showing a radio protocol structure in an LTE system to which the present invention is applied;
3 is a diagram for explaining a modification period in a general SIB delivery method;
4 is an operation flowchart for explaining a general SIB delivery method,
5 is a diagram for explaining a general SIB scheduling method;
6 is an operation flowchart in Example 1;
7 is a block diagram of a terminal operation in Embodiment 1;
8 is a block diagram of an operation of a base station in Embodiment 1;
9 is an operation flowchart in Example 2;
10 is a block diagram of a terminal operation in Embodiment 2;
11 is a block diagram of an operation of a base station in Embodiment 2;
12 is a block diagram of a terminal operation for explaining the present invention;
13 is a block diagram of an operation of a base station for explaining the present invention;
14 is a diagram for explaining a frame structure in TDD;
15 is a diagram for explaining PagingCycle-dynamic-TDD and i_s-dynamic-TDD information;
16 is a flowchart illustrating an operation of a terminal to determine a subframe to perform reverse transmission by selectively applying a first TDD configuration and a second TDD configuration;
17 is a flowchart illustrating an example of a terminal operation for determining a subframe to perform reverse transmission by selectively applying a first TDD configuration and a second TDD configuration;
18 is a flowchart illustrating a terminal operation for determining an operation to be performed in subframe n by selectively applying a first TDD configuration and a second TDD configuration;
19 is a flowchart illustrating a terminal operation for determining a subframe to receive a PHICH by selectively applying a first TDD configuration and a second TDD configuration;
20 is a flowchart illustrating another operation of determining a subframe to receive a PHICH by selectively applying a first TDD configuration and a second TDD configuration;
21 is a flowchart illustrating an example of an operation of determining a subframe to receive a PHICH by selectively applying a first TDD configuration and a second TDD configuration;
22 is a flowchart illustrating a terminal operation in which a terminal temporarily not obtaining a second TDD configuration selects a subframe to perform reverse transmission;
23 is a flowchart illustrating an operation of a terminal in which a terminal temporarily unable to obtain a second TDD configuration selects a subframe to receive a PHICH.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

In describing the embodiments, descriptions of technical contents that are well known in the technical field to which the present invention pertains and are not directly related to the present invention will be omitted. This is to more clearly convey the gist of the present invention by omitting unnecessary description.

For the same reason, some elements in the accompanying drawings are exaggerated, omitted, or schematically illustrated. In addition, the size of each component does not fully reflect the actual size. The same reference numerals are assigned to the same or corresponding components in each drawing.

An embodiment of the present invention relates to a method and apparatus for effectively providing TDD configuration information to a terminal and determining an uplink transmission timing in a mobile communication system supporting TDD.

The first and second embodiments are for a method of effectively transmitting TDD configuration information changed with a short cycle to a terminal, and a third embodiment is for a method of determining an uplink transmission timing in such a situation.

In the IMTA technology, in order to change the ratio of the amount of resources allocated to the uplink and downlink with a short cycle, the TDD configuration information must be quickly changed. To this end, the applied TDD configuration information must be quickly transmitted to the terminal. In the present invention, a scheme for effectively transmitting rapidly changed TDD configuration information to a terminal is proposed. Prior to the description of the present invention, an LTE system to which the present invention is applied, TDD configuration information, and a TDD frame structure will be described.

1 is a diagram showing a structure of an LTE system to which the present invention is applied.

Referring to Figure 1, as shown, the radio access network of the LTE system is a next-generation base station (Evolved Node B, hereinafter ENB, Node B or base station) 105, 110, 115, 120 and MME (125, Mobility Management Entity) And S-GW (130, Serving-Gateway). User equipment (hereinafter referred to as UE or terminal) 135 accesses an external network through ENBs 105 to 120 and S-GW 130.

In FIG. 1, ENBs 105 to 120 correspond to existing Node Bs in the UMTS system. The ENB is connected to the UE 135 through a radio channel and performs a more complex role than the existing Node B. In the LTE system, all user traffic including real-time services such as VoIP (Voice over IP) through Internet protocols are serviced through a shared channel, so status information such as buffer status, available transmission power status, and channel status of UEs A device that collects and performs scheduling is required, and ENB (105 ~ 120) is in charge of this. One ENB typically controls multiple cells. For example, in order to implement a transmission rate of 100 Mbps, the LTE system uses, for example, an orthogonal frequency division multiplexing (OFDM) in a 20 MHz bandwidth as a radio access technology. In addition, an adaptive modulation and coding method (hereinafter referred to as AMC) that determines a modulation scheme and a channel coding rate according to a channel state of the terminal is applied. The S-GW 130 is a device that provides a data bearer, and creates or removes a data bearer under the control of the MME 125. The MME is a device responsible for various control functions as well as a mobility management function for a terminal, and is connected to a plurality of base stations.

2 is a diagram showing a radio protocol structure in an LTE system to which the present invention is applied.

Referring to FIG. 2, the radio protocol of the LTE system consists of Packet Data Convergence Protocol 205 and 240 (PDCP), Radio Link Control 210 and 235 (RLC), and Medium Access Control 215 and 230 (MAC) in a UE and an ENB, respectively. PDCP (Packet Data Convergence Protocol) 205, 240 is in charge of operations such as IP header compression/restore, and radio link control (Radio Link Control, hereinafter referred to as RLC) 210, 235 is a PDCP packet data unit (PDU). ) To the appropriate size. The MACs 215 and 230 are connected to several RLC layer devices configured in one terminal, and perform an operation of multiplexing RLC PDUs to MAC PDUs and demultiplexing RLC PDUs from the MAC PDUs. The physical layers 220 and 225 perform channel coding and modulation of upper layer data, making them into OFDM symbols and transmitting them through a radio channel, or demodulating and channel decoding OFDM symbols received through a radio channel and transmitting them to the upper layers. . In addition, the physical layer also uses HARQ (Hybrid ARQ) for additional error correction, and the receiving end transmits whether or not the packet transmitted by 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 LTE standard supports two types of Duplex: Frequency Division Duplex (FDD) and Time Division Duplex (TDD). In FDD, uplink and downlink have different frequency bands, and in TDD, uplink and downlink use the same frequency band. Accordingly, in TDD, frequency bands must be used alternately in uplink during a specific subframe and downlink during another subframe. The UE must accurately know the subframe in which each phase and downlink are used, and the base station provides such subframe information to the UE in advance. In addition, subframe information used for downlink is referred to as a TDD configuration, and as shown in Table 1, the base station may provide one of a total of 7 TDD configurations. According to the TDD configuration, each subframe is divided into an uplink subframe, a downlink subframe, and a special subframe. In Table 1, a downlink subframe denoted by'D' is used to transmit downlink data, and an uplink subframe denoted by'U' is allocated to transmit uplink data. The special subframe corresponds to a subframe between a downlink subframe and an uplink subframe. The reason for placing the special subframe is that the timing at which each terminal completely receives the downlink subframe and the timing at which each terminal transmits uplink data are different according to the terminal at the location of the terminal. For example, a terminal farther away from the base station receives data from the base station later. Conversely, in order for the base station to receive data from the terminal within a specific time, the terminal must start data transmission at an earlier time. Conversely, there is no need for a special subframe between an uplink subframe and a downlink subframe. Table 1 below shows Uplink-downlink configurations.

Uplink-downlink
configuration Downlink-to-Uplink
Switch-point periodicity Subframe number 0 One 2 3 4 5 6 7 8 9 0 5 ms D S U U U D S U U U One 5 ms D S U U D D S U U D 2 5 ms D S U D D D S U D D 3 10 ms D S U U U D D D D D 4 10 ms D S U U D D D D D D 5 10 ms D S U D D D D D D D 6 5 ms D S U U U D S U U D

14 is a diagram for explaining a frame structure in TDD. One radio frame (radio frame, 1400) having a length of 10 ms consists of 10 subframes. Each subframe is 1 ms and consists of two slots. 14 shows a situation in which subframe 1405 and subframe 1415 are downlink subframes, and subframe 1410 and subframe 1435 are uplink subframes, that is, one of TDD configurations 0, 1, 2, and 6. Therefore, the subframe between them becomes a special subframe. The Special subframe is divided into 3 sections indicated by DwPTS (Downlink Pilot TimeSlot, 1420), GP (Guard Period, 1425), and UpPTS (Uplink Pilot Timeslot, 1430). DwPTS is a time interval for downlink reception, and UpPTS is a time interval for uplink transmission. GP does not perform any transmission/reception. Optimal DwPTS and UpPTS values may vary depending on the propagation environment. Therefore, the base station informs the UE of the appropriate DwPTS and UpPTS values in advance, as shown in Table 2. The TDD configuration in Table 1 and the DwPTS and UpPTS values in Table 2 are included in the IE Tdd-Config of SystemInformationBlockType1 (SIB1) broadcasted from the base station and delivered to the terminal. Table 2 below shows the configuration of special subframe (lengths of DwPTS/GP/UpPTS).

The LTE standard has a frequency band concept as shown in Table 3. The LTE carrier belongs to one frequency band, and parameter values applied when calculating terminal transmit power, etc., vary according to the frequency band. In the carrier aggregation technology, carriers belonging to the same band or different bands can be used together. Therefore, in order to support the direct carrier technology, the terminal implementation will have a plurality of RF (Radio Frequency) modules. If carriers to be used by the UE belong to bands adjacent to each other on a frequency, they may be used in the same RF module, but otherwise, if they belong to bands far apart on a frequency, another RF module should be used. This is because the performance characteristics of the RF module vary greatly depending on the applied frequency band. If carriers to be used by the UE belong to bands adjacent to each other on a frequency and use the same RF module, the same TDD configuration information must be used. This is because different TDD configurations cannot be applied by separating carriers belonging to one RF module. In contrast, since carriers to be used by the terminal belong to bands far apart in frequency, if a plurality of RF modules are used, different TDD configurations can be applied to each carrier. Therefore, when the terminal notifies the base station of whether or not the IMTA technology is supported, it is necessary to classify and inform the base station for each frequency band. Table 3 below shows E-UTRA operating bands.

E-UTRA Operating Band Uplink (UL) operating band
BS receive
UE transmit Downlink (DL) operating band
BS transmit
UE receive Duplex Mode F _{UL_low} -F _{UL_high} F _{DL_low} -F _{DL_high} One 1920 MHz 1980 MHz 2110 MHz 2170 MHz FDD 2 1850 MHz 1910 MHz 1930 MHz 1990 MHz FDD 3 1710 MHz 1785 MHz 1805 MHz 1880 MHz FDD 4 1710 MHz 1755 MHz 2110 MHz 2155 MHz FDD 5 824 MHz 849 MHz 869 MHz 894MHz FDD 6 ¹ 830 MHz 840 MHz 875 MHz 885 MHz FDD 7 2500 MHz 2570 MHz 2620 MHz 2690 MHz FDD 8 880 MHz 915 MHz 925 MHz 960 MHz FDD 9 1749.9 MHz 1784.9 MHz 1844.9 MHz 1879.9 MHz FDD 10 1710 MHz 1770 MHz 2110 MHz 2170 MHz FDD 11 1427.9 MHz 1447.9 MHz 1475.9 MHz 1495.9 MHz FDD 12 699 MHz 716 MHz 729 MHz 746 MHz FDD 13 777 MHz 787 MHz 746 MHz 756 MHz FDD 14 788 MHz 798 MHz 758 MHz 768 MHz FDD 15 Reserved Reserved FDD 16 Reserved Reserved FDD 17 704 MHz 716 MHz 734 MHz 746 MHz FDD 18 815 MHz 830 MHz 860 MHz 875 MHz FDD 19 830 MHz 845 MHz 875 MHz 890 MHz FDD 20 832 MHz 862 MHz 791 MHz 821 MHz FDD 21 1447.9 MHz 1462.9 MHz 1495.9 MHz 1510.9 MHz FDD 22 3410 MHz 3490 MHz 3510 MHz 3590 MHz FDD 23 2000 MHz 2020 MHz 2180 MHz 2200 MHz FDD 24 1626.5 MHz 1660.5 MHz 1525 MHz 1559 MHz FDD 25 1850 MHz 1915 MHz 1930 MHz 1995 MHz FDD 26 814 MHz 849 MHz 859 MHz 894 MHz FDD ... 33 1900 MHz 1920 MHz 1900 MHz 1920 MHz TDD 34 2010 MHz 2025 MHz 2010 MHz 2025 MHz TDD 35 1850 MHz 1910 MHz 1850 MHz 1910 MHz TDD 36 1930 MHz 1990 MHz 1930 MHz 1990 MHz TDD 37 1910 MHz 1930 MHz 1910 MHz 1930 MHz TDD 38 2570 MHz 2620 MHz 2570 MHz 2620 MHz TDD 39 1880 MHz 1920 MHz 1880 MHz 1920 MHz TDD 40 2300 MHz 2400 MHz 2300 MHz 2400 MHz TDD 41 2496 MHz 2690 MHz 2496 MHz 2690 MHz TDD 42 3400 MHz 3600 MHz 3400 MHz 3600 MHz TDD 43 3600 MHz 3800 MHz 3600 MHz 3800 MHz TDD NOTE 1: Band 6 is not applicable

<<Example 1>>

In the first embodiment, dynamic TDD configuration information is transmitted using SIB1, which is one of common information broadcasted from a base station. Before describing a specific method, a general SIB delivery method will be described.

3 is a diagram for explaining a modification period in a general SIB delivery method.

Referring to FIG. 3, in a general SIB delivery method, the concept of a modification period 310 is applied. That is, before SI update, it is notified that the SI 300 is updated through a paging message during the Modification period. If the systemInfoModification IE is present in the paging message, it means that the updated SI 305 is transmitted from the next Modification period. Even if only one of the SI messages is changed, it is indicated in the paging message. Exceptionally, SIB10 and SIN11 that deliver ETWS are updated regardless of the boundary of the modification period. If the Paging message indicates that there is ETWS together with the etws-Indication IE, the terminal immediately attempts to receive SIB10 and 11. The length of the modification period is known as SIB2, and the maximum value is 10.24 seconds.

4 is a flowchart illustrating a general SIB delivery method.

Referring to FIG. 4, the base station determines to update SIB information in step 400. In step 405, the base station includes the SystemInfoModification IE in the paging message and delivers it to the terminal. The paging message indicates that newly updated SIB information is transmitted from the next modification period. In step 410, the UE receives the corresponding Paging message and recognizes whether SIB information is changed in the next modification period. When the next modification period 420 arrives, the UE first attempts SIB1 decoding in step 425. This is because SIB1 has scheduling information of other SIBs. The terminal receives the newly updated SIB information in step 430. The terminal applies the SIB information changed in step 435.

5 is a diagram for explaining a general SIB scheduling method.

Referring to FIG. 5, common information broadcasted from a base station exists up to MIB (MasterInformationBlock, 545) and SIB1 to SIB13, and SIB14 and the like are discussed in order to support new technologies. MIB contains the most essential information such as SFN (System Frame Number) and frequency bandwidth. The MIB is included in the first subframe of every radio frame 535 and transmitted. Since the MIB with the same information is transmitted in 4 radio frames, the period is 40 ms. The SIB1 550 includes cell access and SIB scheduling information. SIB2 is included in the 5th subframe of every even-numbered radio frame and transmitted. The remaining SIB2 to SIB13 are included in one of a plurality of SI messages (555, 560, 565) and transmitted. The SI message composed of a plurality of SIB information is transmitted during the SI window, which is a time interval defined by Si-WindowLength 525, and other SI messages cannot be transmitted repeatedly during the time interval. Si-WindowLength is known to the terminal as SIB1, and is a value commonly applied to all SI messages. A plurality of SIB information included in one SI message is transmitted in one subframe in the SI window in order according to the scheduling information of SIB1. Among the subframes in the SI window, SIB transmission is restricted in the MBSFN subframe, the uplink subframe in the case of TDD, and the subframe in which SIB1 is transmitted (the fifth subframe of the even-numbered radio frame). In addition, SIB information to be transmitted first of the first SI message is fixed to SIB2 530. The first SI message 555 is repeatedly transmitted with a specific period 505. That is, when the first SI message 555 is transmitted in the first SI window 515, it is retransmitted after a specific period 505 has passed. After the second SI message 560 is transmitted in the second SI window 520, it is repeatedly transmitted with a different period 510. The periodic information for each SI message is known to the terminal as SIB1.

In order to inform the UE of dynamic TDD configuration information that changes within several tens of ms or hundreds of ms, SIB1 is most suitable among the SIBs described above. The MIB contains only the most essential information, and there are not many spare bits. In contrast, SIB1 is longer than MIB, but transmitted with a relatively long period, but is shorter than other SIBs. In addition, since it is repeatedly transmitted in a designated subframe, separate scheduling information is not required. As described above, other SIB information must obtain scheduling information from the SIB. When using SIB1, the biggest problem is the SIB delivery process based on the modification period. Assuming that SIB1 includes the dynamic TDD configuration, in order to transmit the updated dynamic TDD configuration to the terminal, it is necessary to notify in advance that the SIB will be changed by paging in the previous modification period at the time of transmitting the changed SIB1. After the modification period has elapsed, the base station will transmit the changed SIB1. This means that when considering the change period of the dynamic TDD configuration, the updated dynamic TDD configuration cannot be notified to the terminal in time. Therefore, in the present invention, dynamic TDD configuration information is included in SIB1, but without following the conventional modification period, the terminal continuously receives and decodes SIB1, and the base station transmits SIB1 including the updated dynamic TDD configuration information. Suggest a plan.

6 is a flowchart of the operation according to the first embodiment.

Referring to FIG. 6, in step 600, the UE performs RRC connection establishment to a base station supporting TDD. In step 605, the terminal provides a capability bit indicating that dynamic TDD configuration can be performed for each frequency band to the base station. The reason why capability bits are needed for each frequency band was explained in detail at the beginning. In step 610, the base station determines whether to perform dynamic TDD configuration for a specific carrier belonging to a specific band to the terminal. In step 615, the base station triggers dynamic TDD by using an RRCConnectionReconfiguration message to the terminal. The terminal receiving the message receives and decodes SIB1 information periodically transmitted in step 620. In step 630, dynamic TDD configuration information is received from SIB1. In step 635, the UE performs dynamic TDD by applying the most recently received dynamic TDD configuration until it receives the updated dynamic TDD configuration information in the next SIB1. In step 640, the terminal receives the updated dynamic TDD configuration information. The terminal repeats the above operation until the dynamic TDD operation is terminated.

7 is a block diagram of a terminal operation according to the first embodiment.

Referring to FIG. 7, in step 700, the UE includes a capability indicator indicating whether dynamic TDD operation can be supported for each frequency band in the UE capability information message. In step 705, the terminal transmits a UE capability information message to the base station. In step 710, the terminal receives an RRCConnectionReconfiguration message from the base station. In step 715, the terminal determines whether to configure the dynamic TDD operation in the message. If the dynamic TDD operation is performed, in step 720, the UE acquires dynamic TDD configuration information from periodically transmitted SIB1. In step 725, the UE performs a dynamic TDD operation by applying the most recent dynamic TDD configuration information. If the dynamic TDD operation is not performed, a conventional general TDD operation is performed in step 730.

8 is a block diagram illustrating an operation of a base station according to the first embodiment.

Referring to FIG. 8, in step 800, the base station receives a UE capability information message including a capability indicator indicating whether dynamic TDD operation can be supported for each frequency band from a specific terminal.

In step 805, the base station determines whether to configure the dynamic TDD operation in the message. If the dynamic TDD operation is configured, in step 810, the base station configures the dynamic TDD operation using an RRCConnectionReconfiguration message. In step 820, the base station transmits an RRCConnectionReconfiguration message to the terminal. In step 825, the base station transmits the most recent dynamic TDD configuration in SIB1.

<<Example 2>>

In the second embodiment, dynamic TDD configuration information is delivered using paging. Before explaining the specific method, a general paging delivery method will be described.

The paging message is not transmitted at any time, but is transmitted in a subframe of a predetermined radio frame for each terminal. Since the transmission time point is known by the base station and the terminal in advance, the terminal only needs to perform the paging message reception operation at the transmission time point. A radio frame in which a paging message is transmitted is referred to as a paging frame (PF), and a subframe in which a paging message is actually transmitted in the PF is referred to as a Paging Occasion (PO). PF and PO are derived by the following two equations.

Ns PO when i_s=0 PO when i_s=1 PO when i_s=2 PO when i_s=3 One 0 N/A N/A N/A 2 0 5 N/A N/A 4 0 One 5 6

In this embodiment, 3 bits indicating the TDD configuration to be applied are added to the paging message. In addition, in order to reduce signaling overhead in the PDCCH, a paging message for dynamic TDD configuration may be transmitted using fixed PF and PO. It is not necessary for all terminals to receive the paging message for the dynamic TDD configuration, and only terminals capable of performing a dynamic TDD operation among terminals in a connected mode need to be received. First, the base station transmits PagingCycle-dynamic-TDD and i_s-dynamic-TDD information by using a dedicated RRC message to a terminal to perform dynamic TDD configuration. PagingCycle-dynamic-TDD represents a radio frame (PF) period in which a paging message including the dynamic TDD configuration information is transmitted. i_s-dynamic-TDD represents PO. i_s-dynamic-TDD can be defined as in Table 4.

15 is a diagram for describing PagingCycle-dynamic-TDD and i_s-dynamic-TDD information.

Referring to FIG. 15, a PagingCycle-dynamic-TDD 1500 is a transmission period of a paging message including the dynamic TDD configuration. The PF 1505 represents a radio frame in which a Paging message including the dynamic TDD configuration information is transmitted. PO 1510 is a subframe in which a paging message indicated by i_s-dynamic-TDD is transmitted. The dynamic TDD configuration information received from the paging is applied until the next paging is received (1515).

9 is a flowchart of the operation according to the second embodiment.

9, in step 900, the UE performs RRC connection establishment to a base station supporting TDD. In step 905, the terminal provides a capability bit indicating that dynamic TDD configuration can be performed for each frequency band to the base station. The reason why capability bits are needed for each frequency band was explained in detail at the beginning. In step 910, the base station determines whether to perform dynamic TDD configuration for a specific carrier belonging to a specific band to the terminal. In step 915, the base station transmits PagingCycle-dynamic-TDD and i_s-dynamic-TDD information to the terminal using an RRCConnectionReconfiguration message. Upon receiving the message, the terminal receives and decodes paging information periodically transmitted in step 920. In step 930, dynamic TDD configuration information is received from paging. In step 935, the UE performs dynamic TDD by applying the most recently received dynamic TDD configuration until it receives the updated dynamic TDD configuration information in the next paging. In step 940, the terminal receives the updated dynamic TDD configuration information. The terminal repeats the above operation until the dynamic TDD operation is terminated.

10 is a block diagram of a terminal operation according to the second embodiment.

Referring to FIG. 10, in step 1000, the UE includes a capability indicator indicating whether dynamic TDD operation can be supported for each frequency band in the UE capability information message. In step 1005, the terminal transmits a UE capability information message to the base station. In step 1010, the terminal receives an RRCConnectionReconfiguration message from the base station. In step 1015, the UE configures a dynamic TDD operation in the message and determines whether PagingCycle-dynamic-TDD and i_s-dynamic-TDD information are included. If the dynamic TDD operation is performed, in step 1020, the UE acquires dynamic TDD configuration information from periodically transmitted paging. In step 1025, the UE performs a dynamic TDD operation by applying the most recent dynamic TDD configuration information. If the dynamic TDD operation is not performed, a conventional general TDD operation is performed in step 1030.

11 is a block diagram illustrating an operation of a base station according to the second embodiment.

Referring to FIG. 11, in step 1100, a base station receives a UE capability information message including a capability indicator indicating whether or not a dynamic TDD operation can be supported for each frequency band from a specific terminal.

In step 1105, the base station determines whether to configure dynamic TDD operation in the message. If the dynamic TDD operation is configured, in step 1110, the base station transmits an RRCConnectionReconfiguration message including PagingCycle-dynamic-TDD and i_s-dynamic-TDD information. In step 1120, the base station transmits an RRCConnectionReconfiguration message to the terminal. In step 1125, the base station transmits the latest dynamic TDD configuration in paging.

<Example 3>

When the UE performs PUSCH transmission, there are two cases in which transmission resources are allocated.

1. Receiving a reverse grant indicating initial transmission or retransmission through a forward control channel (PDCCH)

2. In the random access process, a reverse grant stored in a valid random access response (RAR) is received.

When the UE receives the reverse grant in a subframe n, the UE performs reverse transmission in a subframe (n+k), for example, after a predetermined time elapses. The k is related to a period required for the UE to generate the MAC PDU and perform pre-processing of the physical layer for reverse transmission, and the UE and the base station must use the same value.

Embodiment 3 of the present invention proposes a method and apparatus for differently selecting a reverse subframe to perform reverse transmission according to whether the UE receives the reverse grant through a forward control channel or through an RAR when a UE receives a reverse grant. . In particular, when a dynamic TDD operation is configured in the terminal, k is determined by applying the second TDD configuration to the reverse grant received through the PDCCH, and k is applied by applying the first TDD configuration to the reverse grant received through the RAR. Decide.

16 shows the operation of the terminal according to the present invention.

For reference, the TDD configuration information is an integer between 0 and 6 indicating the configuration of a forward subframe and a reverse subframe special subframe for one radio frame. In the present invention, two types of TDD configuration information are used. The first TDD configuration information is information that can be understood by all terminals, including terminals that do not support dynamic TDD operation, and is transmitted through system information so that all terminals in a corresponding cell can recognize it. The system information may be, for example, System Information Block 1. The SIB1 is repeatedly transmitted with a predetermined period, and in addition to the first TDD configuration information, information essential for determining whether or not the UE camps on the corresponding cell, for example, information on the operator of the corresponding cell, is also received. The first TDD configuration information is stored in a field that can be understood by all terminals, including a terminal of an initial release, that is, a legacy field. The second TDD configuration information is applicable only to terminals supporting dynamic TDD operation, and can be transmitted to the terminal in various ways. The second TDD configuration information is repeatedly transmitted at a predetermined period and can be dynamically changed. The base station determines the most appropriate TDD configuration at a predetermined time in consideration of the current cell load situation or the ratio of forward traffic and reverse traffic, and transmits the second TDD configuration information to the terminals for which dynamic TDD operation is configured in a predetermined manner. do.

Referring to FIG. 16, in step 1605, the UE acquires first TDD configuration information. As described above, the terminal receives predetermined system information and recognizes the first TDD configuration information stored in the legacy field of the system information. The first TDD configuration information has an attribute that is not frequently changed, and when it is changed, a system information change procedure is applied. In step 1610, a dynamic TDD operation is configured for the terminal. When the dynamic TDD operation is configured, it means that the terminal receives a control message in which control information indicating to start the dynamic TDD operation is stored. The dynamic TDD operation refers to an operation of dynamically changing a TDD configuration of a terminal according to a cell load condition. Dynamic TDD operations can be classified into the following two types.

Dynamic TDD operation 1: The TDD configuration can be changed at a predetermined period, and the base station periodically informs the terminal of the TDD configuration to be applied at the present time or in the near future using a predetermined method, for example, predetermined control information. . The TDD setting information relates to a configuration of a predetermined reverse sub-frame, a forward sub-frame, and a special sub-frame indicated by an integer between 0 and 6, similar to the conventional TDD setting information.

Dynamic TDD operation 2: The 10 subframes constituting one radio frame are divided into fixed subframes and changeable subframes. The fixed sub-frame is fixed as a forward sub-frame, a reverse sub-frame, or a special sub-frame, and the changeable sub-frame may be a forward sub-frame or a reverse sub-frame depending on the situation. For example, it can be defined as shown in Table 5 below.

Fixed downlink subframe Subframe #0, #5 Fixed uplink subframe Sub-frame #1, #6 Fixed special subframe Sub Frame #2, #7 Flexible subframe Sub Frame #3, #4, #8, #9

An embodiment of the present invention can be applied to both the dynamic TDD operation 1 and the dynamic TDD operation 2. However, in terms of specific operation of the terminal, some operations may be applied only to one of the two dynamic TDD operations. In step 1615, the terminal acquires second TDD configuration information. The second TDD configuration information is delivered to the terminal through a predetermined control message. The predetermined control message may be system information, an RRC control message, a MAC control message, or may be transmitted through a PDCCH. Step 1615 applies only to dynamic TDD operation 1.

In step 1620, the UE receives a valid reverse grant in subframe n.

In step 1625, the UE checks whether the valid reverse grant is received through the RAR or the PDCCH. If it is received through RAR (Random Access Response, hereinafter RAR), it proceeds to step 1630, and if it is received through PDCCH, it proceeds to step 1645. Receiving a valid reverse grant through RAR has the following meaning.

RAR is transmitted by the base station as a response message to the preamble transmitted by the terminal, and consists of a header and a payload, and information called RAPID (Random Access Preamble ID) is stored in the header, and various kinds of information including reverse grants are stored in the payload. It is stored. After transmitting the random access preamble, the UE monitors whether the RAR is received for a predetermined period, and if the RAPID stored in the RAR is related to the preamble transmitted when the RAR is received, the RAR is a valid RAR and the UE is stored in the RAR. It is to determine that the reverse grant is valid.

Receiving a valid reverse grant through the PDCCH means that a reverse grant masked with the UE's identifier (C-RNTI) has been received through the PDCCH.

In step 1630, the UE checks whether the preamble that caused the RAR transmission was a dedicated preamble or a random preamble. The random access process generally consists of a process in which the UE transmits a preamble, the base station transmits the RAR, and the UE performs reverse transmission according to the reverse grant of the RAR (this is referred to as transmitting message 3). In initiating the random access process, the terminal directly selects a preamble or instructs the base station to use a specific preamble. The former is said to use a random preamble, and the latter is said to use a dedicated preamble. In the case of using the random preamble, the base station cannot know which terminal is performing the random access procedure until message 3 is successfully received. On the other hand, in the case of using the dedicated preamble, the base station can know who the terminal is just by receiving the preamble. For example, the base station can know whether or not dynamic TDD has been configured in the terminal, after receiving message 3 in the case of a random preamble, and when receiving the preamble in the case of a dedicated preamble. If the UE transmits the random preamble and then receives the RAR, it means that the base station allocates a reverse grant to the UE without knowing whether the UE applies the dynamic TDD operation, and the UE proceeds to step 1635. If the RAR is received after transmitting the dedicated preamble, it means that the base station allocates a reverse grant to the terminal while knowing that the terminal applies the dynamic TDD operation, and the terminal proceeds to step 1640.

In step 1635, the UE determines a subframe to perform reverse transmission by applying the TDD configuration indicated in the first TDD configuration information. Proceeding to step 1635 means that the terminal in which the dynamic TDD operation is configured transmits a random preamble and receives a response message thereto. Even if a dynamic TDD operation is applied in a certain cell, since there are also terminals that do not support the dynamic TDD operation in the cell, all terminals are performed like a random access operation and the base station can identify the terminal until a certain time If not possible, even if a dynamic TDD operation is configured in the terminal, the reverse subframe is applied not by the reverse subframe determined by the dynamic TDD operation, but by applying the same rules as other terminals for which the dynamic TDD operation is not configured. It is desirable to decide. Accordingly, in step 1635, the UE determines a subframe to perform backward transmission by applying the TDD configuration indicated in the first TDD configuration information. This specifically means the following operation. The UE performs reverse transmission in the (n+k1)-th subframe for the reverse grant received in subframe n. In this case, k1 is an integer greater than or equal to 6 and is a value corresponding to the first reverse subframe after (n+6). Whether an arbitrary subframe is a reverse subframe may vary depending on the TDD configuration, and in step 1635, the UE applies the first TDD configuration to determine which subframe is the first reverse subframe after (n+6). And performs reverse transmission based on the information. In this case, even if the subframe determined to be the first reverse subframe after (n+6) according to the first TDD configuration information is a forward subframe or a changeable subframe according to the second TDD configuration information, the UE It is determined that the frame is a reverse sub-frame and an operation is performed. The reverse grant of the RAR includes information on uplink transmission resources, information on modulation schemes and coding rates to be applied during uplink transmission, information on the size of data to be transmitted, and 1-bit information indicating whether or not uplink transmission is delayed (hereinafter referred to as uplink transmission delay information). Is stored. If the uplink transmission delay information is set to 0, the terminal performs uplink transmission in the uplink subframe corresponding to k1. When the uplink transmission delay information is set to 1, the terminal performs uplink transmission in the first uplink subframe after that, not in the uplink subframe corresponding to k1. In this case, even when determining the first reverse subframe after k1, the UE is based on the TDD configuration indicated in the first TDD configuration information. The reverse transmission delay is for a kind of load distribution.

In step 1640, the UE determines a subframe to perform reverse transmission by applying the second TDD configuration. Proceeding to step 1640 means that the terminal in which the dynamic TDD operation is configured transmits a dedicated preamble and receives a response message thereto. The base station provides the reverse grant while recognizing that dynamic TDD has been configured to the terminal, and the terminal applies the second TDD configuration information. More specifically, the UE performs reverse transmission in the (n+k1) subframe, and k1 is an integer greater than or equal to 6 and corresponding to the first reverse subframe based on the TDD configuration indicated in the second TDD configuration information. . If the reverse transmission delay information of the RAR reverse grant is 0, the UE selects k1 based on the second TDD configuration and performs reverse transmission in subframe n+k1. If the reverse transmission delay information of the RAR reverse grant is 1, the second TDD Reverse transmission is performed in the first reverse subframe after the subframe corresponding to k1 selected as the setting criterion. In this case, in determining the first reverse subframe after k1, the UE applies the second TDD configuration.

Proceeding to step 1645 means that the base station knowing the fact has allocated the reverse grant to the terminal in which the dynamic TDD operation is configured. The UE determines a subframe to perform reverse transmission by applying the second TDD configuration. The time relationship between the reverse grant received through the PDCCH and the corresponding reverse transmission is defined for each TDD configuration in Table 8-2 (Table 6) of the standard 36.213. Accordingly, the UE receiving the PDCCH reverse grant in subframe n determines k by applying TDD configuration 2 of TDD configuration 1 and TDD configuration 2, and determines a subframe to perform backward transmission according to the determined k. Table 6 below shows Table 8-2 of Standard 36.213.

TDD UL/DL
Configuration subframe number n 0 One 2 3 4 5 6 7 8 9 0 4 6 4 6 One 6 4 6 4 2 4 4 3 4 4 4 4 4 4 5 4 6 7 7 7 7 5

For example, when the UE receives a reverse grant in subframe 0, k is 4 if the TDD configuration is 0, and k is 7 if the TDD configuration is 6. The above operation has been described as an example in FIG. 17.

Referring to FIGS. 16 and 17, the first TDD setting is setting 0 (1705), and the second TDD setting is setting 3 (1710). The terminal received the reverse grant in subframe 0 (1715). If the reverse grant is received through RAR and the UE uses a random preamble, the UE determines k1 by applying the first TDD configuration. That is, when TDD setting 0 is applied among subframes after at least 6 subframes, the first reverse subframe corresponds to k1 and is 7, in the above example. If the uplink transmission delay information is 0, the terminal performs uplink transmission in subframe 7 1720. If the reverse transmission delay information is set to 1, the UE determines the subframe indicated by k1 by applying the first TDD setting, and then applies the first TDD setting again to determine the first reverse subframe 1725 thereafter. do. Then, reverse transmission is performed in the subframe.

If the reverse grant is received through RAR and the UE uses the dedicated preamble, the UE determines k1 by applying the second TDD configuration. That is, when TDD setting 3 is applied among subframes after at least 6 subframes, the first reverse subframe is k1 and becomes 12 in the above example. If the uplink transmission delay information is set to 0, the terminal performs uplink transmission in subframe 2 1730. If the backward transmission delay information is set to 1, the UE determines the subframe indicated by k1 using the second TDD configuration information, and then applies the second TDD configuration again to determine the first backward subframe 1735 thereafter. do. Then, reverse transmission is performed in the subframe.

If the reverse grant is received through the PDCCH, the UE determines k by applying the second TDD configuration. Referring to Table 8-2, when a TDD setting is 3 and a reverse grant is received in subframe 0, k is 4. Accordingly, the UE performs reverse transmission in subframe 4 1740.

The above example relates to a case of using the dynamic TDD operation 1. In the case of using the dynamic TDD operation 2, the difference in terminal operation will be described below.

Steps 1605 and 1610 are the same even when the dynamic TDD operation 2 is used.

When using dynamic TDD operation 2, step 1615 is not necessary.

Steps 1620 to 1635 are also the same even when the dynamic TDD operation 2 is used.

In step 1640, the UE performs uplink transmission in the first subframe among the uplink subframes after 6 subframes and the changeable subframes in the subframe receiving the uplink grant. That is, k1 is an integer greater than 6 and corresponding to a subframe that occurs first among the first reverse subframe and the first changeable subframe. In the example of FIG. 17, the UE performs reverse transmission in subframe 7 (1720, if reverse transmission delay information is set to 0) or subframe 8 (1725, if reverse transmission delay information is set to 1).

In step 1645, the UE performs reverse transmission in the first subframe of the reverse subframe after 4 subframes and the changeable subframe in the subframe receiving the reverse grant. That is, k is an integer greater than 4 and corresponding to a subframe that occurs first among the first reverse subframe and the first changeable subframe. In the example of FIG. 17, the terminal performs reverse transmission in subframe 4 1740.

The UE determines what operation to perform in subframe n before any subframe n starts. The operation is, for example, whether to monitor the PDCCH in the corresponding subframe, transmit the reverse feedback, receive the forward feedback, or perform the PUSCH transmission. In the forward subframe, the UE monitors the PDCCH to determine whether it is scheduled or whether there is data transmitted to it. If a dynamic TDD operation is configured in the terminal, the terminal determines which operation to perform by selectively applying the first TDD configuration and the second TDD configuration. The terminal in which the dynamic TDD operation is not configured always determines what operation to perform by applying the first TDD configuration.

18 is a terminal operation for determining an operation to be performed in subframe n by selectively applying a first TDD configuration and a second TDD configuration.

Referring to FIG. 18, in step 1805, the UE starts a process of determining whether to perform an operation related to a forward subframe or an operation related to a reverse subframe in a subframe.

In step 1810, the UE determines whether to set the dynamic TDD operation. If the dynamic TDD operation has not been set, the process proceeds to step 1815.

In step 1815, the terminal operates as follows.

By applying the first TDD setting, it is determined whether to monitor whether a scheduling message masked with C-RNTI is received through the PDCCH in the corresponding subframe. When the first TDD configuration is applied, if the corresponding subframe is a forward subframe or a special subframe, the UE monitors whether a scheduling message masked with C-RNTI is received through the PDCCH in the subframe.

It is determined whether to receive HARQ feedback in the corresponding subframe by applying the first TDD configuration. The time relationship between PUSCH transmission and HARQ feedback reception is defined for each TDD configuration in 36.213. If the corresponding subframe is a forward subframe based on the first TDD configuration, the UE determines whether the PUSCH is transmitted in a previous predetermined reverse subframe to receive HARQ feedback in the subframe based on the first TDD configuration.

It is determined whether to transmit the PUSCH in the corresponding subframe by applying the first TDD configuration. If the corresponding subframe is a reverse subframe and a reverse grant is received through the PDCCH before k subframe, the UE transmits the PUSCH in the corresponding subframe. The k is determined based on the first TDD setting.

It is determined whether to transmit reverse HARQ feedback in a corresponding subframe by applying the first TDD configuration. The UE transmits the reverse HARQ feedback if the corresponding subframe is a reverse subframe based on the first TDD configuration and a PDSCH is received before a predetermined period defined for each TDD configuration.

It is determined whether or not the RAR masked with RA-RNTI should be monitored through the PDCCH in the corresponding subframe by applying the first TDD setting. The UE transmits a preamble in subframe x, the subframe is a subframe between (x+m) and (x+m+k), and the subframe is a forward subframe or a special frame based on the first TDD configuration. If it is a subframe, the UE monitors whether to receive the RAR masked with RA-RNTI through the PDCCH in the corresponding subframe. The m and k are parameters for a random access response window that specifies from when to when to attempt RAR reception after the UE transmits the preamble. m is a fixed value and k is system information and its length is known. If the terminal does not receive a valid RAR until the random access response window is ended, it starts a procedure of retransmitting the preamble.

It is determined whether to transmit the PUSCH for the RAR reverse grant in the subframe by applying the first TDD configuration. If the corresponding subframe is a reverse subframe and a reverse grant is received through the RAR before the k1 subframe, the UE transmits the PUSCH in the corresponding subframe. The k1 is determined based on the first TDD setting.

In step 1820, the terminal operates as follows. In summary, the UE applies the first TDD configuration for message 3 transmission and RAR reception, but applies the second TDD configuration for the remaining cases.

It is determined whether to monitor whether a scheduling message masked with C-RNTI is received through the PDCCH in the corresponding subframe by applying the second TDD setting. When the second TDD configuration is applied, if the subframe is a forward subframe or a special subframe, the UE monitors whether a scheduling message masked with C-RNTI is received through the PDCCH in the subframe.

It is determined whether to receive HARQ feedback in the corresponding subframe by applying the second TDD configuration. The time relationship between PUSCH transmission and HARQ feedback reception is defined for each TDD configuration in 36.213. If the corresponding subframe is a forward subframe based on the second TDD configuration, the UE determines whether to receive HARQ feedback in the subframe based on the second TDD configuration.

It is determined whether to transmit the PUSCH in the subframe by applying the second TDD configuration. If the corresponding subframe is a reverse subframe and a reverse grant is received through the PDCCH before k subframe, the UE transmits the PUSCH in the corresponding subframe. The k is determined based on the second TDD setting.

It is determined whether to transmit reverse HARQ feedback in the corresponding subframe by applying the second TDD configuration. The UE transmits reverse HARQ feedback if the corresponding subframe is a reverse subframe based on the second TDD configuration, and a PDSCH is received before a predetermined period defined for each TDD configuration.

It is determined whether or not the RAR masked with RA-RNTI should be monitored through the PDCCH in the corresponding subframe by applying the first TDD setting. The UE transmits a preamble in subframe x, the subframe is a subframe between (x+n+m) and (x+m+k), and the subframe is a forward subframe based on the first TDD configuration Or, if it is a special subframe, the UE monitors whether to receive the RAR masked with RA-RNTI through the PDCCH in the corresponding subframe. The m and k are parameters for a random access response window that specifies from when to when to attempt RAR reception after the UE transmits the preamble. m is a fixed value, and k is system information and its length is known. If the terminal does not receive a valid RAR until the random access response window is ended, it starts a procedure of retransmitting the preamble.

It is determined whether to transmit the PUSCH for the RAR reverse grant in the subframe by applying the first TDD configuration. If the corresponding subframe is a reverse subframe and a reverse grant is received through the RAR before the k1 subframe, the UE transmits the PUSCH in the corresponding subframe. The k1 is determined based on the first TDD setting.

Another terminal operation will be described below.

The random access process consists of a process in which the terminal transmits a preamble, the base station transmits a random access response, and the terminal transmits reverse data. At this time, the terminal transmits reverse data and receives HARQ feedback for this. If a dynamic TDD operation is configured for the terminal, the terminal should selectively apply the first TDD configuration or the second TDD configuration in determining the timing at which the HARQ feedback is received.

Fig. 19 shows the related terminal operation.

Referring to FIG. 19, in step 1905, the UE acquires first TDD configuration information. As described above, the terminal receives predetermined system information and recognizes the first TDD configuration information stored in the legacy field of the system information. The first TDD configuration information has an attribute that is not frequently changed, and when it is changed, a system information change procedure is applied. In step 1910, a dynamic TDD operation is configured for the terminal. When the dynamic TDD operation is configured, it means that the terminal receives a control message in which control information indicating to start the dynamic TDD operation is stored. The dynamic TDD operation refers to an operation of dynamically changing the TDD configuration of the terminal according to the load condition of the terminal.

In step 1915, the terminal acquires second TDD configuration information. The second TDD configuration information is delivered to the terminal through a predetermined control message. The predetermined control message may be system information, an RRC control message, a MAC control message, or may be transmitted through a PDCCH. Step 1915 applies only to dynamic TDD operation 1.

In step 1920, the UE receives forward HARQ feedback in a subframe i. Since the forward HARQ feedback is transmitted and received through a PHICH (Physical Harq Indicator Channel), receiving the forward HARQ feedback has the same meaning as receiving the PHICH. The UE proceeds to step 1925 to determine whether the PHICH is HARQ ACK/NACK information for the PUSCH transmitted in which reverse subframe.

In step 1925, the UE checks whether the reverse grant that caused PUSCH transmission corresponding to the received PHICH is delivered through RAR or PDCCH. If it is delivered through RAR, it proceeds to step 1930, and if it is delivered through PDCCH, it proceeds to step 1940. In step 1930, the UE checks whether the preamble that caused the RAR transmission (or the preamble corresponding to the RAPID stored in the RAR) was a dedicated preamble or a random preamble. If the terminal transmits the random preamble and then receives the RAR, it means that the base station transmits the reverse grant to the terminal without knowing whether the terminal applies the dynamic TDD operation, and the terminal proceeds to step 1935. If the RAR is received after transmitting the dedicated preamble, it means that the base station has transmitted the reverse grant to the terminal while knowing that the terminal applies the dynamic TDD operation, and the terminal proceeds to step 1940.

In step 1935, the UE determines in which reverse subframe the PHICH is related to the transmitted PUSCH by applying the TDD configuration indicated in the first TDD configuration information. In short, the PHICH is for the PUSCH transmitted in the subframe (i-k), and k is determined based on the TDD configuration indicated in the first TDD configuration information. The relationship between the TDD setting and k is defined in Table 8.3-1 shown in Table 7 of Standard 36.213. For example, if the UE receives the PHICH in subframe 0 and the TDD configuration at the time point is set to 0, k is 7 and the PHICH is HARQ feedback for the PUSCH transmitted in (i-7).

Table 7 below is a table showing Table 8. 3-1 of Standard 36.213. The above table may represent the k value in the TDD setting 0-6.

TDD UL/DL
Configuration subframe number i 0 One 2 3 4 5 6 7 8 9 0 7 4 7 4 One 4 6 4 6 2 6 6 3 6 6 6 4 6 6 5 6 6 6 4 7 4 6

In step 1940, the UE determines in which reverse subframe the PHICH is related to the transmitted PUSCH by applying the TDD configuration indicated in the second TDD configuration information. In short, the PHICH is for the PUSCH transmitted in the subframe (i-k), and k is determined based on the TDD configuration indicated in the second TDD configuration information. The relationship between TDD setting and k is defined in Table 8.3-1 of standard 36.213.

20 shows another operation of the terminal related to the operation.

Referring to Figs. 19 and 20, the operation shown in Fig. 20 and the operation shown in Fig. 19 lead to essentially the same result and provide the same effect.

2005 to 2015 are the same as 1905 to 1915.

In step 2020, the UE performs PUSCH transmission in subframe n. The UE proceeds to step 2025 to determine a subframe to receive feedback on the PUSCH transmission.

In step 2025, the UE checks whether the reverse grant that caused the PUSCH transmission is delivered through the RAR or the PDCCH. If it is received through the RAR, it proceeds to step 2030, and if it is received through the PDCCH, it proceeds to step 2040.

In step 2030, the UE checks whether the preamble related to the RAR is a dedicated preamble or a random preamble. If the UE transmits the random preamble and then receives the RAR, it means that the base station transmits the reverse grant to the UE without knowing whether the UE applies the dynamic TDD operation, and the UE proceeds to step 2035. If the RAR is received after transmitting the dedicated preamble, it means that the base station has transmitted a reverse grant to the terminal while knowing that the terminal applies the dynamic TDD operation, and the terminal proceeds to step 2040.

In step 2035, the UE determines in which subframe the PHICH is to be received by applying the first TDD configuration. In short, the UE receives the PHICH in a subframe (n+k). The k is determined based on the TDD configuration indicated in the first TDD configuration information. The relationship between the TDD setting and k can be determined in Table 8.3-1 of standard 36.213. For example, if the UE transmits the PUSCH in subframe 2 and TDD configuration 1, the PHICH is received in subframe 6.

In step 2040, the UE determines in which subframe the PHICH is to be received by applying the second TDD configuration. In short, the UE receives the PHICH in a subframe (n+k).

In Fig. 21, the above operation will be described as an example.

Referring to FIG. 21, a first TDD setting is a setting of 0 (2105), and a second TDD setting is a setting of 3 (2110). The UE transmitted the PUSCH in subframe 3 (2115). If the reverse grant related to the PUSCH transmission is received through RAR, and the UE uses a random preamble, the UE determines k by applying the first TDD configuration. Referring to Table 8.3-1, when PUSCH is transmitted in subframe 3 and the TDD setting is 0, k of subframe 0 is 7 and the distance between subframe 0 and subframe 3 is 7, so k is 7 And the UE receives the PHICH in subframe 0 2120. If the uplink grant is received through the RAR and the terminal uses a dedicated preamble, or the uplink grant is received through the PDCCH, the terminal determines k using the second TDD configuration information. Referring to Table 8.3-1, when PUSCH is transmitted in subframe 3 and the TDD configuration is 3, k of subframe 9 is 6, and the distance between subframe 9 and subframe 3 is also 6 subframes. 6 is selected and the PHICH is received in subframe 9 2125.

The above example relates to a case of using the dynamic TDD operation 1. In the case of using the dynamic TDD operation 2, the difference in terminal operation will be described below.

For steps 2005 to 2010 and steps 2020 to 2035, the terminal operation in the case of applying the dynamic TDD operation 1 and the terminal operation in the case of applying the dynamic TDD operation 2 are the same. If dynamic TDD operation 2 is used, the 2015 operation is not necessary.

In step 2040, the UE determines a subframe to receive the PHICH according to the following criteria.

[standard]

A subframe that appears first among a forward fixed subframe, a special fixed subframe, and a changeable subframe at least 4 subframes after the subframe transmitting the PUSCH.

In the example of FIG. 21, when the UE transmits the PUSCH in subframe 3, it receives the PHICH in subframe 8 2130 that satisfies the above condition.

There may be a case in which the terminal in which the dynamic TDD operation is configured is temporarily not aware of the second TDD configuration. For example, the UE is performing a discontinuous reception operation in a subframe in which the second TDD configuration is transmitted, or a forward signal is not received in the subframe in order to measure a different frequency.

22 illustrates an operation taken when a terminal temporarily not aware of the second TDD configuration receives a reverse grant.

Referring to FIG. 22, steps 2205 and 2210 are the same as steps 1605 and 1610.

In step 2215, a reverse grant is received. For convenience, a subframe in which the reverse subframe is received is referred to as subframe n.

In step 2220, the terminal checks whether it has the second TDD configuration information to be applied at the time point. As described above, the second TDD configuration information is transmitted with a certain period. For example, the second TDD configuration information to be applied to the m-th time period is transmitted in a predetermined subframe of an arbitrary (m-1)-th time period, and the UE receives the reverse grant in a random sub-frame of the m-th time period. It checks whether it has the second TDD configuration information to be applied to the time period. If so, the terminal proceeds to step 2225. If not, proceed to step 2230.

In step 2225, the UE determines a subframe to perform PUSCH transmission by applying a first TDD configuration or a second TDD configuration in consideration of whether the reverse grant is received through the RAR or the PDCCH.

In step 2230, the UE checks whether the reverse grant is received through the RAR or the PDCCH. If it is received through the PDCCH, it proceeds to step 2240, and if it is received through the RAR, it proceeds to step 2235.

Proceeding to step 2240 means that the UE cannot determine k even though it has to determine k by applying the second TDD configuration. Accordingly, the UE does not perform initial transmission even if the reverse grant indicates initial transmission, and does not perform retransmission even if retransmission is indicated. However, CURRENT_NB_TX, which records the number of transmissions, or CURRENT_IRV related to the redundancy version to be used for the next transmission is normally increased.

In step 2235, the UE checks whether the preamble causing RAR reception was a dedicated preamble or a random preamble. If it was a random preamble, it proceeds to step 2245, and if it was a dedicated preamble, it proceeds to step 2250.

Proceeding to step 2245 means that in a random access process using a random preamble, it is necessary to perform reverse transmission for the reverse grant of the RAR. Even if the UE does not know the second TDD configuration, it applies the first TDD configuration to determine k1, and in the subframe (n+k1) (if the reverse delay is set to 0) or the first reverse after the subframe (n+k1) In a subframe (if the reverse delay is set to 1), the PUSCH is transmitted using the allocated reverse transmission resource.

Proceeding to step 2250 means that in the random access process using the dedicated preamble, reverse transmission for the reverse grant of the RAR should be performed. Accordingly, the UE must determine k1 by applying the second TDD configuration, but cannot determine k1 because the UE does not know the second TDD configuration to be applied in the corresponding time period. The UE ignores the uplink grant, that is, does not perform PUSCH transmission using uplink transmission resources allocated from the uplink grant, and initiates a preamble retransmission procedure. That is, the preamble is retransmitted in a reverse subframe that satisfies a predetermined condition. The predetermined condition is a reverse subframe in which a preamble transmission resource is set, which exists after at least 4 subframes when the first TDD setting is applied.

FIG. 23 illustrates an operation related to reception of a PHICH by a terminal temporarily not aware of the second TDD configuration.

Referring to FIG. 23, steps 2305 and 2310 are the same as steps 1605 and 1610.

In step 2315, the UE performs PUSCH transmission. For convenience, the subframe in which the PUSCH transmission is performed is referred to as subframe n.

In step 2320, the terminal checks whether it has the second TDD configuration information to be applied at the time point. As described above, the second TDD configuration information is transmitted with a certain period. For example, the second TDD configuration information to be applied to the m-th time period is transmitted in a predetermined subframe of an arbitrary (m-1)-th time period, and the terminal receives the reverse grant in an arbitrary sub-frame of the m-th time period. It checks whether it has the second TDD configuration information to be applied to the time period. If so, the terminal proceeds to step 2325. If not, proceed to step 2330.

In step 2325, the UE determines a subframe to receive the PHICH by applying the first TDD configuration or the second TDD configuration in consideration of whether the reverse grant that caused the PUSCH transmission is received through the RAR or the PDCCH.

In step 2330, the UE checks whether the reverse grant that caused the PUSCH transmission is received through the RAR or the PDCCH. If it is received through the PDCCH, it proceeds to step 2340, and if it is received through the RAR, it proceeds to step 2335.

Proceeding to step 2340 means that the UE must determine the subframe to receive the PHICH by applying the second TDD configuration, but cannot determine the subframe because it does not know the second TDD configuration. Therefore, the terminal stops attempting to receive the PHICH. In addition, HARQ_FEEDBACK is set to ACK so that non-adaptive retransmission for the PUSCH does not occur. Alternatively, the buffer of the HARQ process related to the PUSCH transmission is flushed. HARQ_FEEDBACK is a variable that manages the most recent HARQ feedback information for each predetermined HARQ process, and if it is set to NACK, non-adaptive retransmission is performed, and if it is set to ACK, transmission is not performed until a separate retransmission command is received. . HARQ_FEEDBACK should be set according to the actually received HARQ feedback, but in the present invention, if the PHICH is not received because the second TDD configuration is not known, HARQ_FEEDBACK is set to ACK even if the HARQ feedback is not received.

In step 2335, the UE checks whether the preamble causing RAR reception was a dedicated preamble or a random preamble. If it was a random preamble, it proceeds to step 2345, and if it was a dedicated preamble, it proceeds to step 2340.

Proceeding to step 2345 means that a reverse grant was received through RAR in a random access process using a random preamble, and PUSCH transmission was performed accordingly. Accordingly, even if the UE does not know the second TDD configuration, the UE determines k by applying the first TDD configuration and receives a PHICH (or HARQ feedback) in a subframe (n+k). 12 is a block diagram showing the internal structure of a terminal to which the present invention is applied.

The terminal transmits/receives data to/from the upper layer 1210, and transmits/receives control messages through the control message processor 1215. When transmitting a control signal or data to the base station, the terminal multiplexes through the multiplexing device 1205 under the control of the controller 1220 and then transmits the data through the transmitter 1200. On the other hand, upon reception, the terminal receives the physical signal to the receiver 1200 under the control of the controller 1220, and then demultiplexes the received signal to the demultiplexer 1205, and each higher layer 1210 according to the message information. ) Or to the control message processing unit 1215.

13 is a block diagram showing the configuration of a base station according to the present invention.

Referring to FIG. 13, the illustrated base station apparatus includes a transmission/reception unit 1305, a control unit 1310, a multiplexing and demultiplexing unit 1320, a control message processing unit 1335, each type of upper layer processing unit 1325, 930, and a scheduler. (1315) is included.

The transmission/reception unit 1305 transmits data and a predetermined control signal through a forward carrier and receives data and a predetermined control signal through a reverse carrier. When multiple carriers are set, the transmission/reception unit 1305 performs data transmission/reception and control signal transmission/reception through the multiple carriers.

The multiplexing and demultiplexing unit 1320 multiplexes the data generated by the upper layer processing units 1325 and 1330 or the control message processing unit 1335, or demultiplexes the data received from the transmission/reception unit 1305, and the appropriate upper layer processing unit 1325, 1330), a control message processing unit 1335, or a control unit 1310. The control unit 1310 determines whether to apply the band-specific measurement gap to a specific terminal, and determines whether to include the configuration information in the RRCConnectionReconfiguration message.

The control message processing unit 1335 receives an instruction from the control unit, generates an RRCConnectionRecnofiguraiton to be transmitted to the terminal, and delivers it to a lower layer.

The upper layer processing units 1325 and 1330 can be configured for each service for each terminal, and process data generated from user services such as FTP or VoIP, and transfer them to the multiplexing and demultiplexing unit 1320, or the multiplexing and demultiplexing unit 1320 Processes the data transmitted from) and delivers it to the upper layer service application.

The scheduler 1315 allocates transmission resources to the terminal at an appropriate time in consideration of the buffer state of the terminal, the channel state, and the active time of the terminal, and processes the transmission/reception unit to process the signal transmitted by the terminal or to transmit the signal to the terminal. do.

Those of ordinary skill in the art to which the present invention pertains will appreciate that the present invention can be implemented in other specific forms without changing the technical spirit or essential features thereof. Therefore, it should be understood that the embodiments described above are illustrative and non-limiting in all respects. The scope of the present invention is indicated by the scope of the claims to be described later rather than the detailed description, and all changes or modified forms derived from the meaning and scope of the claims and the concept of equivalents thereof are included in the scope of the present invention. It must be interpreted.

Meanwhile, in the present specification and drawings, a preferred embodiment of the present invention has been disclosed, and although specific terms are used, this is only used in a general meaning to easily describe the technical content of the present invention and to aid understanding of the present invention. It is not intended to limit the scope of the invention. In addition to the embodiments disclosed herein, it is apparent to those of ordinary skill in the art that other modified examples based on the technical idea of the present invention can be implemented.

Claims (16)

In a method by a terminal in a wireless communication system,
Receiving a system information block message including first time division duplex (TDD) uplink/downlink (UL/DL) configuration information from the base station;
Receiving, from the base station, a physical downlink control channel (PDCCH) including downlink control information including information related to a second TDD UL/DL configuration;
Receiving uplink scheduling information for the terminal from the base station; And
Transmitting data in a subframe to the base station based on the uplink scheduling information; Including,
When the data is changed from an uplink subframe determined based on the first TDD UL/DL configuration information to a downlink subframe determined based on information related to the second TDD UL/DL configuration, the downlink subframe A method, characterized in that it is not transmitted in a subframe changed to a frame. The method of claim 1,
Transmitting the data,
When the uplink scheduling information is received in a random access response message, the data is transmitted in a subframe determined based on the first TDD UL/DL configuration information. The method of claim 1,
Transmitting the data,
When the uplink scheduling information is received on the PDCCH, the data is transmitted in a subframe determined based on information related to the second TDD UL/DL configuration. The method of claim 1,
Transmitting the data,
When the uplink scheduling information is received through a random access response message in subframe n, data corresponding to the uplink scheduling information is transmitted in subframe n+k based on the first TDD UL/DL configuration information, and ,
The method, characterized in that k is an integer of 6 or more. In a terminal in a wireless communication system,
A transmission/reception unit; And
Receiving a system information block message including a first time division duplex (TDD) uplink/downlink (UL/DL) configuration information from the base station,
A physical downlink control channel (PDCCH) including downlink control information including information related to a second TDD UL/DL configuration is received from the base station,
Receiving uplink scheduling information for the terminal from the base station,
A control unit for controlling the transmission/reception unit to transmit data in a subframe to the base station based on the uplink scheduling information; Including,
When the data is changed from an uplink subframe determined based on the first TDD UL/DL configuration information to a downlink subframe determined based on information related to the second TDD UL/DL configuration, the downlink subframe A terminal, characterized in that it is not transmitted in the subframe changed to the frame. The method of claim 5,
The control unit,
And when the uplink scheduling information is received in a random access response message, controlling the transceiver to transmit the data in a subframe determined based on the first TDD UL/DL configuration information. The method of claim 5,
The control unit,
And when the uplink scheduling information is received on the PDCCH, controlling the transmission/reception unit to transmit the data in a subframe determined based on information related to the second TDD UL/DL configuration. The method of claim 5,
The control unit,
When the uplink scheduling information is received through a random access response message in subframe n, to transmit data corresponding to the uplink scheduling information in subframe n+k based on the first TDD UL/DL configuration information Controlling the transmission/reception unit,
The terminal, characterized in that the k is an integer of 6 or more. In a method by a base station in a wireless communication system,
Transmitting a system information block message including first time division duplex (TDD) uplink/downlink (UL/DL) configuration information to the terminal;
Transmitting a physical downlink control channel (PDCCH) including downlink control information including information related to a second TDD UL/DL configuration to the terminal;
Transmitting uplink scheduling information for the terminal to the terminal; And
Receiving data in a subframe based on the uplink scheduling information from the terminal; Including,
When the data is changed from an uplink subframe determined based on the first TDD UL/DL configuration information to a downlink subframe determined based on information related to the second TDD UL/DL configuration, the downlink subframe A method, characterized in that not received in the subframe changed to the frame. The method of claim 9,
Receiving the data,
When the uplink scheduling information is transmitted in a random access response message, receiving the data in a subframe determined based on the first TDD UL/DL configuration information. The method of claim 9,
Receiving the data,
When the uplink scheduling information is transmitted on the PDCCH, receiving the data in a subframe determined based on information related to the second TDD UL/DL configuration. The method of claim 9,
Receiving the data,
When the uplink scheduling information is transmitted through a random access response message in subframe n, data corresponding to the uplink scheduling information is received in subframe n+k based on the first TDD UL/DL configuration information, and ,
The method, characterized in that k is an integer of 6 or more. In a base station in a wireless communication system,
A transmission/reception unit; And
Transmitting a system information block message including a first time division duplex (TDD) uplink/downlink (UL/DL) configuration information to the terminal, and
Transmitting a physical downlink control channel (PDCCH) including downlink control information including information related to the second TDD UL/DL configuration to the terminal,
Transmits uplink scheduling information for the terminal to the terminal,
A control unit controlling the transmission/reception unit to receive data in a subframe based on the uplink scheduling information from the terminal; Including,
When the data is changed from an uplink subframe determined based on the first TDD UL/DL configuration information to a downlink subframe determined based on information related to the second TDD UL/DL configuration, the downlink subframe The base station, characterized in that not received in the subframe changed to the frame. The method of claim 13,
The control unit,
And when the uplink scheduling information is transmitted in a random access response message, controlling the transceiver to receive the data in a subframe determined based on the first TDD UL/DL configuration information. The method of claim 13,
The control unit,
And when the uplink scheduling information is transmitted on the PDCCH, controlling the transceiver to receive the data in a subframe determined based on information related to the second TDD UL/DL configuration. The method of claim 13,
The control unit,
When the uplink scheduling information is transmitted through a random access response message in subframe n, data corresponding to the uplink scheduling information is received in subframe n+k based on the first TDD UL/DL configuration information. Controlling the transmission/reception unit,
The base station, characterized in that k is an integer of 6 or more.

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