KR20210063308A - Method and apparatus to efficiently provide TDD configuration to terminal in the mobile communication system - Google Patents

Abstract

A method for setting time division duplex (TDD) of a terminal in a communication system according to one 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 a backward grant (uplink grant) from the base station; and determining to apply the first TDD configuration or the second TDD configuration based on the method in which the backward grant is received. According to one embodiment of the present invention, the TDD is set to a shorter period in a terminal supporting TDD in a wireless communication system, and the TDD is set in the terminal more quickly and variably according to the communication situation.

Description

Method and apparatus for effectively providing TDD configuration information to a terminal and determining uplink transmission timing in a mobile communication system supporting TDD {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. Such a mobile communication system has reached a stage in which it is possible to provide 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, standardization work for LTE-A (Long Term Evolution Advanced) in 3GPP is in progress. 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 goal of commercialization by 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 network structure, or a method of making wireless protocols as close to a wireless channel as possible are under discussion.

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

Recently, discussions about an advanced LTE communication system (LTE-Advanced, LTE-A) that improve transmission speed by grafting various new technologies to the LTE communication system are in full swing. IMTA (Interference Mitigation and Traffic adaptation) technology is one of several technologies being studied in LTE-A. The IMTA technology is a technology applied to TDD and has a short cycle for the purpose of controlling the amount of traffic and interference generated 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 this IMTA technology, the LTE-A system needs to be improved in several ways.

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

In order to achieve the above object, the method of the terminal in the communication system according to an embodiment of the present invention is a first time division duplex (TDD) uplink / downlink (uplink / downlink, UL / DL from the base station) ) receiving system information including configuration information, receiving information related to second TDD UL/DL configuration information from the base station, receiving uplink scheduling information from the base station, the uplink scheduling information If received based on the first identifier, transmitting a message to the base station based on the uplink scheduling information and the first TDD UL/DL configuration information, and the uplink scheduling information is received based on the second identifier In the case of the above, the method may include transmitting a message to the base station based on the uplink scheduling information and information related to the second TDD UL/DL configuration information.

In a communication system according to another embodiment of the present invention, the terminal includes a first time division duplex (TDD) uplink/downlink (UL/DL) configuration information from a transceiver and a base station. When system information is received, information related to second TDD UL/DL configuration information is received from the base station, uplink scheduling information is received from the base station, and the uplink scheduling information is received based on a first identifier , transmits a message to the base station based on the uplink scheduling information and the first TDD UL/DL configuration information, and when the uplink scheduling information is received based on a second identifier, the uplink scheduling information and the and a controller for controlling the transceiver to transmit a message to the base station based on information related to the second TDD UL/DL configuration information.

In a communication system according to another embodiment of the present invention, the method of the base station includes system information including first time division duplex (TDD) uplink/downlink (UL/DL) configuration information to the terminal. transmitting, transmitting information related to second TDD UL/DL configuration information to the terminal, transmitting uplink scheduling information to the terminal, the uplink scheduling information is transmitted based on the first identifier case, receiving a message from the terminal based on the uplink scheduling information and the first TDD UL/DL configuration information, and when the uplink scheduling information is transmitted based on a second identifier, the uplink scheduling information and receiving a message from the terminal based on information related to the second TDD UL/DL configuration information.

In a communication system according to another embodiment of the present invention, in a communication system, a base station provides first time division duplex (TDD) uplink/downlink (UL/DL) configuration information to a transceiver and a terminal. Transmitting system information including, transmitting information related to second TDD UL/DL configuration information to the terminal, and transmitting uplink scheduling information to the terminal, wherein the uplink scheduling information is based on the first identifier. When transmitted, a message is received from the terminal based on the uplink scheduling information and the first TDD UL/DL configuration information, and when the uplink scheduling information is transmitted based on the second identifier, the uplink scheduling and a controller controlling the transceiver to receive a message from the terminal based on information and information related to the second TDD UL/DL configuration information.

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

1 is a diagram showing the 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 view 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 Embodiment 1;
7 is a terminal operation block diagram in Embodiment 1;
8 is a block diagram of a base station in Embodiment 1;
9 is an operation flowchart in Embodiment 2;
10 is a terminal operation block diagram in Embodiment 2;
11 is a block diagram of a base station in Example 2;
12 is a terminal operation block diagram for explaining the present invention;
13 is a block diagram 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 for determining 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 an operation of a terminal 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 an operation of a terminal 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 an operation of a terminal for determining a subframe for receiving 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 for receiving a PHICH by selectively applying a first TDD configuration and a second TDD configuration;
21 is a flowchart illustrating an example of determining a subframe for receiving 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 failing to acquire a second TDD configuration selects a subframe to perform reverse transmission;
23 is a flowchart illustrating a terminal operation in which a terminal that has not temporarily obtained 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 relate to a method of effectively delivering TDD configuration information changed with a short cycle to a UE, and the third embodiment relates to a method of determining an uplink transmission timing in such a situation.

In the IMTA technology, in order to have a short cycle and to change the ratio of the amount of resources allocated to uplink and downlink, TDD configuration information must be changed quickly. To this end, the applied TDD configuration information should be quickly delivered to the terminal. The present invention proposes a method for effectively delivering rapidly changing TDD configuration information to a terminal. 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 the structure of an LTE system to which the present invention is applied.

Referring to FIG. 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). A user equipment (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 of 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 the Internet protocol, are serviced through a shared channel, so status information such as buffer status, available transmission power status, and channel status of UEs A device for scheduling is required, and the ENB (105 to 120) is responsible for 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, Orthogonal Frequency Division Multiplexing (hereinafter referred to as OFDM) as a radio access technology in a 20 MHz bandwidth. In addition, an Adaptive Modulation & Coding (AMC) method that determines a modulation scheme and a channel coding rate according to the 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 the mobility management function for the UE, and is connected to a number of base stations.

2 is a diagram illustrating 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, 235 (RLC), and Medium Access Control 215 and 230 (MAC) in the UE and ENB, respectively. PDCP (Packet Data Convergence Protocol) (205, 240) is in charge of operations such as IP header compression / restoration, radio link control (Radio Link Control, hereinafter referred to as RLC) (210, 235) PDCP PDU (Packet Data Unit) ) is reconstructed to an appropriate size. The MACs 215 and 230 are connected to several RLC layer devices configured in one terminal, and perform operations of multiplexing RLC PDUs into MAC PDUs and demultiplexing RLC PDUs from MAC PDUs. The physical layers 220 and 225 channel-code and modulate the upper layer data, make OFDM symbols and transmit them over the wireless channel, or demodulate the OFDM symbols received through the wireless channel, decode the channels, and deliver them to the upper layers. . In addition, the physical layer uses Hybrid ARQ (HARQ) for additional error correction, and the receiving end transmits 1 bit whether or not the packet transmitted from the transmitting end is received. 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) may be transmitted through a physical channel.

The LTE standard supports two duplexes: 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 should be alternately used in uplink during a specific subframe and downlink during another subframe. The terminal must know exactly the subframes used for each phase and downlink, and the base station provides such subframe information to the terminal in advance. Subframe information used for uplink and downlink is referred to as a TDD configuration, and as shown in Table 1, the base station may provide one of a total of seven 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 the downlink subframe and the uplink subframe. The reason for providing the special subframe is that, depending on the location of the terminal, the timing at which each terminal completely receives the downlink subframe and the timing at which each terminal transmits uplink data are different. For example, a terminal far 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 needs to start data transmission at an earlier time. Conversely, there is no need for a special subframe between the uplink subframe and the 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 in between becomes a special subframe. The special subframe is divided into 3 sections indicated by Downlink Pilot TimeSlot (DwPTS, 1420), Guard Period (GP), 1425 (Uplink Pilot Timeslot, 1430) (UpPTS). DwPTS is a time interval for downlink reception, and UpPTS is a time interval for uplink transmission. GP does not perform any transmission and reception. The optimal DwPTS and UpPTS values may vary depending on the propagation environment. Accordingly, the base station notifies the terminal 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) broadcast 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 concept of a frequency band as shown in Table 3. The LTE carrier belongs to one frequency band, and parameter values applied when calculating terminal transmission power, etc. vary according to the frequency band. In the carrier aggregation technique, carriers belonging to the same band or different bands may be used together. Therefore, in order to support the direct carrier technology, the terminal will have a plurality of RF (Radio Frequency) modules. If the carriers to be used by the terminal belong to bands adjacent to each other in frequency, they can be used in the same RF module. Otherwise, if they belong to bands far apart in frequency, another RF module will have to be used. This is because the performance characteristics of the RF module vary greatly depending on the applied frequency band. If the carriers to be used by the terminal belong to bands adjacent to each other in frequency and use the same RF module, the same TDD configuration information should be used. This is because different TDD settings cannot be applied by separating carriers belonging to one RF module. In contrast, if carriers to be used by the terminal belong to bands far apart in frequency, and thus a plurality of RF modules are used, different TDD settings may be applied to each carrier. Therefore, when the terminal notifies the base station whether or not the IMTA technology is supported, it is necessary to divide the information 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 Embodiment 1, dynamic TDD configuration information is transmitted using SIB1, which is one of common information broadcast by the base station. Before describing a specific method, a general SIB delivery method will be described.

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

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

4 is an operation flowchart for explaining 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 terminal receives the paging message and recognizes whether the 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 newly updated SIB information in step 430 . The UE applies the changed SIB information in step 435 .

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

Referring to FIG. 5 , common information broadcast from the base station exists up to MIB (Master Information Block, 545) and SIB1 to SIB13. In order to support new technologies, SIB14 and the like are being discussed. 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. SIB1 550 includes cell access and SIB scheduling information. SIB2 is transmitted while being included in the 5th subframe of every even-numbered radio frame. The remaining SIB2 to SIB13 are included in one of the plurality of SI messages (555, 560, 565) and transmitted. An SI message composed of a plurality of SIB information is transmitted during an SI window, which is a time interval defined by Si-WindowLength 525 , and other SI messages cannot be repeatedly transmitted during the time interval. Si-WindowLength is known to the UE as SIB1, and is a value commonly applied to all SI messages. A plurality of pieces of SIB information included in one SI message are sequentially transmitted in one subframe within the SI window according to the scheduling information of SIB1. Among subframes within the SI window, SIB transmission is restricted in the MBSFN subframe, the uplink subframe in 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 , after a specific period 505 , it is retransmitted. After being transmitted in the second SI window 520 , the second SI message 560 is repeatedly transmitted with a different period 510 . The period information for each SI message is known to the UE as SIB1.

Among the SIBs described above, SIB1 is most suitable to inform the UE of dynamic TDD configuration information that is changed within tens of ms or hundreds of ms at a short time. MIB contains only the most essential information, and there are not many spare bits. In comparison, 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 the dynamic TDD configuration is included in SIB1, in order to deliver the updated dynamic TDD configuration to the UE, it is necessary to inform 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 in consideration of the change period of the dynamic TDD configuration, the updated dynamic TDD configuration cannot be notified to the UE in a timely manner. Therefore, in the present invention, dynamic TDD configuration information is included in SIB1, but does not follow the conventional modification period, the terminal continuously receives and decodes SIB1, and the base station transmits SIB1 immediately including the updated dynamic TDD configuration information. suggest a way

6 is an operation flowchart in 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 the base station with a capability bit indicating that dynamic TDD configuration can be performed for each frequency band. The reason why capability bits are required for each frequency band was explained in detail in the introduction. In step 610, the base station determines to the terminal whether to perform dynamic TDD configuration for a specific carrier belonging to a specific band. In step 615, the base station triggers dynamic TDD to the terminal by using the RRCConnectionReconfiguration message. Upon receiving the message, the terminal 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 UE receives updated dynamic TDD configuration information. The UE 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 it can support the dynamic TDD operation 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 UE determines whether to configure 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 of a base station in 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 a dynamic TDD operation can be supported for each frequency band from a specific terminal.

In step 805, the base station determines whether to configure 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 the 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 transmitted using paging. Before describing a 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 radio frame predetermined for each UE. Since the transmission time is known in advance by the base station and the terminal, the terminal only needs to perform the paging message reception operation at the transmission time. A radio frame in which a paging message is transmitted is called a paging frame (PF), and a subframe in which a paging message is actually transmitted in the PF is called 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 dynamic TDD operation among terminals in the connected mode need to be received. First, the base station transmits PagingCycle-dynamic-TDD and i_s-dynamic-TDD information to a terminal to perform dynamic TDD configuration using a dedicated RRC message. PagingCycle-dynamic-TDD indicates 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 explaining 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. PF 1505 indicates a radio frame in which a paging message including the dynamic TDD configuration information is transmitted. The 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 an operation flowchart in the second embodiment.

Referring to FIG. 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 required for each frequency band was explained in detail in the introduction. In step 910, the base station determines to the terminal whether to perform dynamic TDD configuration for a specific carrier belonging to a specific band. In step 915, the base station transmits PagingCycle-dynamic-TDD and i_s-dynamic-TDD information to the terminal using the RRCConnectionReconfiguration message. Upon receiving the message, the terminal receives and decodes periodically transmitted paging information 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 updated dynamic TDD configuration information in the next paging. In step 940, the UE receives updated dynamic TDD configuration information. The UE 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 it can support the dynamic TDD operation 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 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 of a base station operation according to the second embodiment.

Referring to FIG. 11 , in step 1100, the base station receives a UE capability information message including a capability indicator indicating whether 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 most recent dynamic TDD configuration in the 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. During the random access process, a reverse grant stored in a valid RAR (valid random access response) is received.

When the terminal receives the uplink grant in an arbitrary subframe n, the terminal performs uplink transmission in, for example, a subframe (n+k) after a predetermined time elapses. The k is related to the period required for the terminal to generate a MAC PDU and perform physical layer preprocessing for uplink transmission, and the terminal and the base station should use the same value.

In Embodiment 3 of the present invention, when the UE receives the reverse grant, 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 an RAR are provided. . In particular, when a dynamic TDD operation is configured in the UE, k is determined by applying the second TDD setting to the reverse grant received through the PDCCH, and the first TDD setting is applied to the reverse grant received through the RAR to obtain k. 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 backward 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 all terminals, including terminals that do not support dynamic TDD operation, can understand, and is transmitted through system information so that all terminals of the corresponding cell can recognize it. The system information may be, for example, System Information Block 1. SIB1 is transmitted repeatedly with a predetermined period, and, in addition to the first TDD configuration information, essential information for determining whether the terminal will camp on the corresponding cell, for example, information about the operator of the corresponding cell, is also received. The first TDD configuration information is accommodated in a field that all terminals, including terminals of an initial release, can understand, that is, a legacy field. The second TDD configuration information is applicable only to terminals supporting a dynamic TDD operation, and can be delivered to the terminal in various ways. The second TDD configuration information is repeatedly transmitted with a predetermined period and can be dynamically changed. The base station determines the most suitable TDD configuration at a predetermined time in consideration of the load situation of the current cell or the ratio of forward and reverse traffic, and delivers the second TDD configuration information to terminals configured for dynamic TDD operation in a predetermined manner. do.

Referring to FIG. 16 , in step 1605, the terminal 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 a property 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 UE. Setting the dynamic TDD operation means that the terminal receives a control message containing control information instructing to start the dynamic TDD operation. The dynamic TDD operation refers to an operation of dynamically changing the TDD configuration of the terminal according to a load condition of a cell. The dynamic TDD operation may be classified into the following two types.

Dynamic TDD operation 1: TDD configuration may 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 to the terminal. . The TDD configuration information relates to the configuration of a predetermined uplink subframe, a forward subframe, and a special subframe indicated by an integer between 0 and 6, like the conventional TDD configuration information.

Dynamic TDD operation 2: Ten subframes constituting one radio frame are divided into fixed subframes and changeable subframes. The fixed subframe is fixed as a forward subframe, a backward subframe, or a special subframe, and the changeable subframe may be a forward subframe or a backward subframe depending on circumstances. For example, it may be defined as shown in Table 5 below.

fixed downlink subframe Subframes #0, #5 Fixed uplink subframe Subframe #1, #6 fixed special subframe Subframe #2, #7 flexible subframe Subframes #3, #4, #8, #9

The embodiment of the present invention is applicable to both the dynamic TDD operation 1 and the dynamic TDD operation 2 . However, in terms of specific UE operation, some operations may be applied only to one of the two dynamic TDD operations. In step 1615, the UE acquires second TDD configuration information. The second TDD configuration information is transmitted 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 transmitted through a PDCCH. Step 1615 applies only to dynamic TDD operation 1.

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

In step 1625, the UE checks whether the valid uplink grant is received through RAR or 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 uplink 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. It consists of a header and a payload. The header contains information called RAPID (Random Access Preamble ID), and the payload contains various information including reverse grant. are housed After transmitting the random access preamble, the UE monitors whether or not RAR is received for a predetermined period, and when the RAR is received, if the RAPID stored in the RAR relates to the preamble it has transmitted, the RAR is a valid RAR, and the UE is stored in the RAR It is to determine that the reversed grant is valid.

Receiving a valid uplink grant through the PDCCH means receiving the uplink grant masked by the terminal identifier (C-RNTI) through the PDCCH.

In step 1630, the UE checks whether the preamble causing the RAR transmission is a dedicated preamble or a random preamble. The random access procedure 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 RAR reverse grant (this is referred to as transmitting message 3). In initiating the random access procedure, the UE directly selects a preamble or instructs the BS to use a specific preamble. The former is said to use a random preamble, and the latter is said to use a dedicated preamble. When 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, when 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 is 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 terminal receives the RAR after transmitting the random preamble, it means that the base station allocates the reverse grant to the terminal without knowing whether the terminal applies the dynamic TDD operation, and the terminal proceeds to step 1635. If the RAR is received after transmitting the dedicated preamble, it means that the base station has allocated the reverse grant to the terminal while knowing that the terminal applies a 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 UE configured with the dynamic TDD operation transmits a random preamble and receives a response message. Even if the dynamic TDD operation is applied in any cell, since there are terminals that do not support the dynamic TDD operation in the cell, all terminals perform the same as in the random access operation, and the base station identifies the terminal until a certain point in time. If not, even if the dynamic TDD operation is configured in the terminal, the reverse subframe is not configured by the dynamic TDD operation, but the reverse subframe is generated 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 reverse 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 uplink 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 uplink subframe after (n+6). Whether an arbitrary subframe is an uplink subframe may vary depending on the TDD configuration, and in step 1635, the UE determines which subframe is the first uplink subframe after (n+6) by applying the first TDD configuration. and performs reverse transmission based on the information. At this time, even if the subframe determined as the first uplink 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 terminal It is determined that the frame is a backward sub-frame and an operation is performed. In the reverse grant of RAR, reverse transmission resource information, information on the modulation scheme and coding rate to be applied during reverse transmission, information on the size of data to be transmitted, and 1-bit information indicating whether or not the reverse transmission is delayed (hereinafter, reverse transmission delay information) is housed If the reverse transmission delay information is set to 0, the terminal performs reverse transmission in the reverse subframe corresponding to k1. If the uplink transmission delay information is set to 1, the UE performs uplink transmission in the first uplink subframe thereafter, not in the uplink subframe corresponding to k1. In this case, even in determining the first uplink subframe after k1, the UE uses the TDD configuration indicated in the first TDD configuration information as a reference. 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 UE configured with the dynamic TDD operation transmits a dedicated preamble and receives a response message. The base station provides the reverse grant while recognizing that dynamic TDD is configured to the terminal, and the terminal applies the second TDD configuration information. More specifically, the UE performs reverse transmission in (n+k1) subframes, where k1 is an integer greater than or equal to 6 based on the TDD configuration indicated in the second TDD configuration information and corresponding to the first reverse subframe. . 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 After the subframe corresponding to k1 selected as the setting criterion, the uplink transmission is performed in the first uplink subframe. In this case, in determining the first uplink subframe after k1, the UE applies the second TDD configuration.

Proceeding to step 1645 means that the base station knowing the fact 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 uplink grant received through the PDCCH and the corresponding uplink transmission is defined for each TDD configuration in Table 8-2 (Table 6) of standard 36.213. Accordingly, the UE receiving the PDCCH reverse grant in subframe n applies TDD configuration 2 among TDD configuration 1 and TDD configuration 2 to determine k, and determines a subframe to perform reverse transmission according to the determined k. Table 6 below is a table showing 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 the uplink grant in subframe 0, if the TDD configuration is 0, k is 4, and if the TDD configuration is 6, k is 7. The above operation has been described with reference to FIG. 17 as an example.

16 and 17 , the first TDD setting is set 0 ( 1705 ), and the second TDD setting is set 3 ( 1710 ). The UE receives the uplink 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 the TDD setting 0 is applied among the subframes after at least 6 subframes, the first uplink subframe corresponds to k1 and is 7 in the above example. If the reverse transmission delay information is 0, the UE performs reverse 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 again applies the first TDD setting to determine the subsequent first reverse subframe 1725 do. Then, reverse transmission is performed in the subframe.

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

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

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

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

If dynamic TDD operation 2 is used, step 1615 is not necessary.

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

In step 1640, the UE performs uplink transmission in the first subframe among the uplink subframe after 6 subframes and the changeable subframe in the subframe in which the uplink grant is received. That is, k1 is an integer greater than 6 and corresponding to a subframe that occurs first among the first uplink 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 uplink transmission in the first subframe among the uplink subframe after subframe 4 and the changeable subframe in the subframe in which the uplink grant is received. That is, k is an integer greater than 4 and corresponding to a subframe occurring first among the first uplink subframe and the first changeable subframe. In the example of FIG. 17 , the UE performs reverse transmission in subframe 4 1740 .

The UE determines which 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, whether to transmit reverse feedback, whether to receive forward feedback, or whether to perform PUSCH transmission. The UE monitors the PDCCH in the forward subframe to determine whether scheduling or whether data is transmitted to itself. If a dynamic TDD operation is configured in the UE, the UE determines which operation to perform by selectively applying the first TDD configuration and the second TDD configuration. A UE for which a dynamic TDD operation is not configured always applies the first TDD configuration to determine which operation to perform.

18 is an operation of a terminal 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 backward subframe in an arbitrary subframe.

In step 1810, the UE determines whether to set the dynamic TDD operation. If the dynamic TDD operation is not set, the process proceeds to step 1815. If it is set, the process proceeds to step 1820.

In step 1815, the terminal operates as follows.

It is determined whether or not to monitor whether a scheduling message masked with C-RNTI is received through the PDCCH in the corresponding subframe by applying the first TDD configuration. 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 was transmitted in a previous predetermined backward subframe to receive HARQ feedback in the subframe based on the first TDD configuration.

It is determined whether PUSCH is transmitted in the corresponding subframe by applying the first TDD configuration. The UE transmits the PUSCH in the subframe if the corresponding subframe is the uplink subframe, and if it receives the uplink grant through the PDCCH before the k subframe. The k is determined based on the first TDD setting.

It is determined whether to transmit the uplink HARQ feedback in the corresponding subframe by applying the first TDD configuration. If the corresponding subframe is the uplink subframe based on the first TDD configuration and the PDSCH is received before a predetermined period defined for each TDD configuration, the terminal transmits the uplink HARQ feedback.

Determine whether to monitor whether RAR masked with RA-RNTI is received through PDCCH in the corresponding subframe by applying the first TDD configuration. The UE has transmitted the preamble in subframe x, the corresponding subframe is a subframe between (x+m) and (x+m+k), and the corresponding subframe is a forward subframe or special based on the first TDD configuration. If it is a subframe, the UE monitors whether the RAR masked with the RA-RNTI is received through the PDCCH in the corresponding subframe. The m and k are parameters for a random access response window that defines from when to when the UE attempts to receive the RAR after transmitting the preamble. m is a fixed value and k is the system information and its length is known. If the UE does not receive a valid RAR until the random access response window ends, the UE enters a procedure for retransmitting the preamble.

It is determined whether to transmit the PUSCH for the RAR uplink grant in the corresponding subframe by applying the first TDD configuration. If the corresponding subframe is the uplink subframe and the uplink 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 or not to monitor whether a scheduling message masked with C-RNTI is received through the PDCCH in the corresponding subframe by applying the second TDD configuration. When the second 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 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 PUSCH is transmitted in the corresponding subframe by applying the second TDD configuration. The UE transmits the PUSCH in the subframe if the corresponding subframe is the uplink subframe, and if it receives the uplink grant through the PDCCH before the k subframe. The k is determined based on the second TDD setting.

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

Determine whether to monitor whether RAR masked with RA-RNTI is received through PDCCH in the corresponding subframe by applying the first TDD configuration. The UE has transmitted the preamble in subframe x, the corresponding subframe is a subframe between (x+n+m) and (x+m+k), and the corresponding subframe is a forward subframe based on the first TDD configuration. Alternatively, if it is a special subframe, the UE monitors whether RAR masked with RA-RNTI is received through the PDCCH in the corresponding subframe. The m and k are parameters for a random access response window that defines from when to when the UE attempts to receive the RAR after transmitting the preamble. For m, a fixed value is used, and k is system information and its length is known. If the UE does not receive a valid RAR until the random access response window ends, the UE enters the procedure of retransmitting the preamble.

It is determined whether to transmit the PUSCH for the RAR uplink grant in the corresponding subframe by applying the first TDD configuration. If the corresponding subframe is the uplink subframe and the uplink 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 UE transmits uplink data and then receives HARQ feedback for it. If a dynamic TDD operation is configured for the UE, the UE should selectively apply the first TDD configuration or the second TDD configuration when determining the time of receiving the HARQ feedback.

19 shows a 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 a property 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 UE. Setting the dynamic TDD operation means that the terminal receives a control message containing control information instructing to start the dynamic TDD operation. 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 UE acquires second TDD configuration information. The second TDD configuration information is transmitted 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 transmitted through a PDCCH. Step 1915 applies only to dynamic TDD operation 1.

In step 1920, the UE receives the forward HARQ feedback in an arbitrary subframe i. Since the forward HARQ feedback is transmitted and received through a Physical Harq Indicator Channel (PHICH), 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 a PUSCH transmitted in which uplink subframe.

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

In step 1935, the UE determines in which uplink subframe the PHICH relates to the PUSCH transmitted by applying the TDD configuration indicated in the first TDD configuration information. In other words, 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 TDD setting and k is defined in Table 8.3-1 shown in Table 7 of Specification 36.213. For example, if the UE receives the PHICH in subframe 0 and the TDD configuration at the time is set 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 indicate k values in TDD settings 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 uplink subframe the PHICH relates to a PUSCH transmitted by applying the TDD configuration indicated in the second TDD configuration information. In other words, 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 Specification 36.213.

Another operation of the terminal related to the operation is shown in FIG. 20 .

19 and 20 , the operation illustrated in FIG. 20 and the operation illustrated in FIG. 19 lead to essentially the same result and provide the same effect.

2005 ~ 2015 is the same as 1905 ~ 1915.

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

In step 2025, the UE checks whether the reverse grant causing the PUSCH transmission is transmitted through RAR or PDCCH. If it is received through RAR, it proceeds to step 2030, and if it is received through 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 terminal receives the RAR after transmitting the random preamble, it means that the base station has transmitted the reverse grant to the terminal without knowing whether the terminal applies the dynamic TDD operation, and the terminal proceeds to step 2035. 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 a dynamic TDD operation, and the terminal proceeds to step 2040.

In step 2035, the UE determines in which subframe to receive the PHICH by applying the first TDD configuration. In other words, 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 TDD setting and k can be determined in Table 8.3-1 of Specification 36.213. For example, if the UE has transmitted 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 to receive the PHICH by applying the second TDD configuration. In other words, the UE receives the PHICH in a subframe (n+k).

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

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

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

For steps 2005 to 2010 and 2020 to 2035, the terminal operation to which the dynamic TDD operation 1 is applied and the terminal operation to which the dynamic TDD operation 2 is applied are the same. If dynamic TDD operation 2 is used, the 2015 operation is not required.

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 in which the PUSCH is transmitted.

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

There may be a case in which the UE configured with the dynamic TDD operation does not temporarily recognize 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 case in which a forward signal is not received in the subframe in order to measure another frequency.

22 illustrates an operation taken by a terminal that has not temporarily recognized the second TDD configuration when receiving 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, the subframe in which the uplink subframe is received is referred to as subframe n.

In step 2220, the terminal checks whether it has second TDD configuration information to be applied at the time. As described above, the second TDD configuration information is transmitted with a constant period. For example, 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 when the terminal receives a reverse grant in an arbitrary subframe of the m-th time period, the m-th time period It is to check whether the second TDD configuration information to be applied to the time period is included. If yes, 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 the first TDD configuration or the second TDD configuration in consideration of whether the uplink 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 should determine k by applying the second TDD configuration. Therefore, the UE does not perform the initial transmission even if the reverse grant indicates initial transmission, and does not perform retransmission even if retransmission is indicated. However, CURRENT_NB_TX that 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 is a dedicated preamble or a random preamble. If it is a random preamble, it proceeds to step 2245. If it is a dedicated preamble, it proceeds to step 2250.

Proceeding to step 2245 means that reverse transmission of the RAR reverse grant should be performed in the random access process using the random preamble. Even if the UE does not know the second TDD configuration, it determines k1 by applying the first TDD configuration, and in the subframe (n+k1) (if the reverse delay is set to 0) or the first reverse direction after the subframe (n+k1) In the 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 reverse transmission of the RAR reverse grant should be performed in the random access process using the dedicated preamble. Therefore, the UE must determine k1 by applying the second TDD setting, but cannot determine k1 because the UE does not know the second TDD setting to be applied in the corresponding time period. The UE ignores the uplink grant, that is, does not perform PUSCH transmission using the uplink transmission resource allocated in the uplink grant, and initiates a preamble retransmission procedure. That is, the preamble is retransmitted in an uplink subframe that satisfies a predetermined condition. The predetermined condition is an uplink subframe in which a preamble transmission resource is configured, which exists after at least 4 subframes when the first TDD configuration is applied.

23 illustrates an operation related to PHICH reception of a UE that has not temporarily recognized 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 UE checks whether it has the second TDD configuration information to be applied at the time. As described above, the second TDD configuration information is transmitted with a constant period. For example, 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 when the terminal receives a reverse grant in an arbitrary subframe of the m-th time period, the m-th time period It is to check whether the second TDD configuration information to be applied to the time period is included. If yes, the terminal proceeds to step 2325. If not, proceed to step 2330.

In step 2325, the UE determines a subframe in which to receive the PHICH by applying the first TDD configuration or the second TDD configuration by considering whether the uplink grant causing PUSCH transmission is received through the RAR or the PDCCH.

In step 2330, the UE checks whether the reverse grant causing 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 a 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 UE stops the attempt 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 HARQ process. If it is set to NACK, non-adaptive retransmission is performed. 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 HARQ feedback actually received, 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 is a dedicated preamble or a random preamble. If it is a random preamble, it proceeds to step 2345. If it is 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. Therefore, even if the UE does not know the second TDD configuration, it determines k by applying the first TDD configuration and receives the PHICH (or HARQ feedback) in the subframe (n+k). 12 is a block diagram illustrating an internal structure of a terminal to which the present invention is applied.

The terminal transmits and receives data to and from the upper layer 1210 , and transmits and receives control messages through the control message processing unit 1215 . In addition, when transmitting a control signal or data to the base station, the terminal transmits data through the transmitter 1200 after multiplexing through the multiplexing device 1205 under the control of the controller 1220 . On the other hand, upon reception, the terminal receives the physical signal from the receiver 1200 under the control of the controller 1220, then demultiplexes the received signal with the demultiplexer 1205, and the upper layer 1210 according to each message information. ) or 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 transceiver unit 1305, a control unit 1310, a multiplexing and demultiplexing unit 1320, a control message processing unit 1335, various upper layer processing units 1325 and 930, and a scheduler. (1315).

The transceiver 1305 transmits data and a predetermined control signal on a forward carrier and receives data and a predetermined control signal on a reverse carrier. When a plurality of carriers are configured, the transceiver 1305 performs data transmission/reception and control signal transmission/reception on the plurality of 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 transceiver 1305 to an appropriate upper layer processing unit 1325, 1330 ), the control message processing unit 1335 , or the control unit 1310 . The controller 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 generates an RRCConnectionRecnofiguraiton to be transmitted to the UE in response to an instruction from the control unit, and transmits it to a lower layer.

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

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, the active time of the terminal, etc., and processes the signal transmitted by the terminal to the transceiver or transmits 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 their equivalent concepts are included in the scope of the present invention. It must be interpreted.

On the other hand, in the present specification and drawings, preferred embodiments of the present invention have been disclosed, and although specific terms are used, these are only used in a general sense to easily explain the technical content of the present invention and help the understanding of the present invention, It is not intended to limit the scope of the invention. It will be apparent to those of ordinary skill in the art to which the present invention pertains that other modifications based on the technical spirit of the present invention can be implemented in addition to the embodiments disclosed herein.

105, 110, 115, 120: next-generation base station (Evolved Node B, hereinafter ENB, Node B or base station)
125: MME (Mobility Management Entity)
130: S-GW
135: user equipment (User Equipment, hereinafter UE or terminal)

Claims (20)

A method of a terminal in a communication system, comprising:
Receiving system information including first time division duplex (TDD) uplink/downlink (UL/DL) configuration information from a base station;
receiving information related to second TDD UL/DL configuration information from the base station;
receiving uplink scheduling information from the base station;
when the uplink scheduling information is received based on the first identifier, transmitting a message to the base station based on the uplink scheduling information and the first TDD UL/DL configuration information; and
when the uplink scheduling information is received based on the second identifier, transmitting a message to the base station based on the uplink scheduling information and information related to the second TDD UL/DL configuration information; How to include. The method of claim 1,
Receiving information related to the second TDD UL/DL configuration information includes:
receiving control information including information related to the second TDD UL/DL configuration information from the base station; Method, characterized in that it further comprises. The method of claim 1,
When the uplink scheduling information is received in subframe n based on the first identifier, a message corresponding to the uplink scheduling information is transmitted in subframe n+k,
wherein k is an integer greater than or equal to 6, and is identified based on the first TDD UL/DL configuration. The method of claim 1,
When the uplink scheduling information is received based on the first identifier, the uplink scheduling information is included in a response to the preamble. The method of claim 1,
The first identifier is a random access-radio network temporary identifier (RA-RNTI),
The second identifier is a cell-radio network temporary identifier (C-RNTI). In a terminal in a communication system,
A transmission/reception unit; and
Receive system information including first time division duplex (TDD) uplink/downlink (UL/DL) configuration information from the base station, and second TDD UL/DL configuration information from the base station Receive information related to, receive uplink scheduling information from the base station, and when the uplink scheduling information is received based on the first identifier, the uplink scheduling information and the first TDD UL/DL configuration information transmits a message to the base station based on the base station, and when the uplink scheduling information is received based on the second identifier, to the base station based on the uplink scheduling information and information related to the second TDD UL/DL configuration information. a control unit controlling the transceiver to transmit a message; A terminal comprising a. The method of claim 6,
When information related to the second TDD UL/DL configuration information is received from the base station, control information including information related to the second TDD UL/DL configuration information is received. The method of claim 6,
When the uplink scheduling information is received in subframe n based on the first identifier, a message corresponding to the uplink scheduling information is transmitted in subframe n+k,
Wherein k is an integer greater than or equal to 6, the terminal, characterized in that it is confirmed based on the first TDD UL / DL configuration. The method of claim 6,
When the uplink scheduling information is received based on the first identifier, the uplink scheduling information is included in a response to the preamble. The method of claim 6,
The first identifier is a random access-radio network temporary identifier (RA-RNTI),
The second identifier is a cell-radio network temporary identifier (C-RNTI). A method of a base station in a communication system, comprising:
transmitting system information including first time division duplex (TDD) uplink/downlink (UL/DL) configuration information to the terminal;
transmitting information related to second TDD UL/DL configuration information to the terminal;
transmitting uplink scheduling information to the terminal;
receiving a message from the terminal based on the uplink scheduling information and the first TDD UL/DL configuration information when the uplink scheduling information is transmitted based on the first identifier; and
receiving a message from the terminal based on the uplink scheduling information and information related to the second TDD UL/DL configuration information when the uplink scheduling information is transmitted based on the second identifier; How to include. The method of claim 11,
Transmitting information related to the second TDD UL/DL configuration information includes:
transmitting control information including information related to the second TDD UL/DL configuration information to the terminal; Method, characterized in that it further comprises. The method of claim 11,
When the uplink scheduling information is received in subframe n based on the first identifier, the message corresponding to the uplink scheduling information is received in subframe n+k,
wherein k is an integer greater than or equal to 6, and is identified based on the first TDD UL/DL configuration. The method of claim 11,
When the uplink scheduling information is transmitted based on the first identifier, the uplink scheduling information is included in a response to the preamble. The method of claim 11,
The first identifier is a random access-radio network temporary identifier (RA-RNTI),
The second identifier is a cell-radio network temporary identifier (C-RNTI). In a base station in a communication system,
A transmission/reception unit; and
Transmits system information including first time division duplex (TDD) uplink/downlink (UL/DL) configuration information to the terminal, and second TDD UL/DL configuration information to the terminal transmits information related to , transmits uplink scheduling information to the terminal, and when the uplink scheduling information is transmitted based on the first identifier, the uplink scheduling information and the first TDD UL/DL configuration information based on the message received from the terminal, and when the uplink scheduling information is transmitted based on the second identifier, from the terminal based on the uplink scheduling information and information related to the second TDD UL/DL configuration information. a control unit controlling the transceiver to receive a message; A base station comprising a. The method of claim 16,
When information related to the second TDD UL/DL configuration information is transmitted, control information including information related to the second TDD UL/DL configuration information is transmitted to the terminal. The method of claim 16,
When the uplink scheduling information is received in subframe n based on the first identifier, the message corresponding to the uplink scheduling information is received in subframe n+k,
Wherein k is an integer greater than or equal to 6, the base station, characterized in that it is identified based on the first TDD UL / DL configuration. The method of claim 16,
When the uplink scheduling information is transmitted based on the first identifier, the uplink scheduling information is included in a response to the preamble. The method of claim 16,
The first identifier is a random access-radio network temporary identifier (RA-RNTI),
The second identifier is a cell-radio network temporary identifier (C-RNTI).

Images