KR20190028145A - Method, apparatus, and system for downlink control information in wireless communication system - Google Patents

Abstract

The present invention relates to a method, apparatus and system for designing downlink control information in a wireless communication system, to minimize the downlink control information when transferring the downlink control information to a terminal configured to receive a code block group (CBG) based transmission in a mobile communication system. According to the present invention, the method for designing downlink control information in a wireless communication system reduces the payload size of the downlink control information when new data indication (NDI), CBG transmission information (CBGTI), CBG flushing information (CBGFI), a transport block (TB)/CBG flag, a modulation and coding scheme (MCS), and a redundancy version (RV), which are information which can be included in the downlink control information of a terminal configured by CBG transmission.

Description

TECHNICAL FIELD [0001] The present invention relates to a method, an apparatus, and a system for downlink control information design in a wireless communication system,

The present invention relates to a wireless communication system, and more particularly, to a downlink control information design in order to support CBG-based transmission in a wireless communication system.

3GPP LTE (-A) defines uplink / downlink physical channels for physical layer signal transmission. For example, a physical uplink shared channel (PUSCH) which is a physical channel for transmitting data in the uplink, a physical uplink control channel (PUCCH) for transmitting a control signal, and a physical random access channel (PRACH) A physical downlink shared channel (PDSCH) for transmitting data in downlink, a physical control format indicator channel (PCFICH), a physical downlink control channel (PDCCH), a physical hybrid ARQ indicator channel (PHICH) ).

A downlink control channel (PDCCH / EPDCCH) of the channels is a channel for transmitting uplink / downlink scheduling assignment control information, uplink transmission power control information, and other control information to one or a plurality of terminals. Since there is a limitation on the resources available for the PDCCH that can be transmitted at one time, it is not possible to allocate different resources to each terminal, and the control information should be transmitted to any terminal by sharing resources. For example, in 3GPP LTE (-A), four Resource Elements (REs) are grouped together to form REGs (Resource Element Groups), nine CCEs (Control Channel Elements), and one or a plurality of CCEs And informs the UE of a resource, and a plurality of UEs can share the CCE. Here, the number of CCEs to be combined is called CCE coupling level, and the resource to which CCE is allocated according to the possible CCE coupling level is called a search space. The search space may include a common search space defined for each base station and a terminal-specific or UE-specific search space defined for each terminal. The UE performs decoding on the number of possible CCE combining cases in the search space and can determine whether it corresponds to its own PDCCH through a user equipment (UE) identifier included in the PDCCH. Therefore, it takes a long time to decode the PDCCH and energy consumption is inevitable.

Efforts are underway to develop an improved 5G or pre-5G communication system to meet the growing demand for wireless data traffic after commercialization of the 4G communication system. For this reason, a 5G communication system or a pre-5G communication system is called a system after a 4G network (Beyond 4G network) communication system or after a LTE system (Post LTE). To achieve a high data rate, 5G communication systems are being considered for implementation in very high frequency (mmWave) bands (e.g., 60 gigahertz (60GHz) bands). In order to mitigate the path loss of the radio wave in the very high frequency band and to increase the propagation distance of the radio wave, in the 5G communication system, beamforming, massive MIMO, full-dimension MIMO (FD-MIMO ), Array antennas, analog beam-forming, and large scale antenna technologies are being discussed. In order to improve the network of the system, the 5G communication system has developed an advanced small cell, an advanced small cell, a cloud radio access network (cloud RAN), an ultra-dense network, (D2D), a wireless backhaul, a moving network, cooperative communication, Coordinated Multi-Points (CoMP), and interference cancellation Have been developed. In addition, in the 5G system, the Advanced Coding Modulation (ACM) scheme, Hybrid FSK and QAM Modulation (FQAM) and Sliding Window Superposition Coding (SWSC), the advanced connection technology, Filter Bank Multi Carrier (FBMC) (non-orthogonal multiple access), and SCMA (sparse code multiple access).

On the other hand, the Internet is evolving into an Internet of Things (IoT) network in which information is exchanged between distributed components such as objects in a human-centered connection network where humans generate and consume information. IoE (Internet of Everything) technology, which combines IoT technology with big data processing technology through connection with cloud servers, is also emerging. In order to implement IoT, technology elements such as sensing technology, wired / wireless communication, network infrastructure, service interface technology and security technology are required. In recent years, sensor network, machine to machine , M2M), and MTC (Machine Type Communication). In the IoT environment, an intelligent IT (Internet Technology) service can be provided that collects and analyzes data generated from connected objects to create new value in human life. IoT is a field of smart home, smart building, smart city, smart car or connected car, smart grid, health care, smart home appliance, and advanced medical service through fusion of existing information technology . ≪ / RTI >

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

Generally, a mobile communication system has been developed to provide voice service while ensuring the user's activity. However, the mobile communication system is gradually expanding not only to voice but also to data service, and now it has developed to the extent of providing high-speed data service. However, in a mobile communication system in which a service is currently provided, a lack of resources and users demand higher speed services, and therefore, a more advanced mobile communication system is required.

As mentioned earlier, future 5G technologies require lower latency data transmission due to the emergence of new applications such as real-time control and tactile internet, The delay is expected to be reduced to 1ms. 5G aims to provide a data delay that is about 10 times lower than the conventional one. To solve this problem, 5G is expected to propose a communication system using a mini-slot having a shorter TTI period (e.g., 0.2ms) in addition to the existing slot (or subframe).

In mobile communication, a base station simultaneously uses a slot and a mini-slot to simultaneously support users having various requirements. In particular, it is expected to use slot / mini-slot multiplexing method to puncture a resource to be used as a slot to provide a low-delay service and to transmit a mini-slot. A user performing a slot-based operation may not be able to transmit information of one or more CBs (code blocks) of the slot by puncturing, and other users' information is transmitted to the corresponding CB, which causes considerable performance deterioration.

A TB (Transport Block), which is a unit transmitted from the 3GPP LTE (-A) to the PDSCH, is attached with a TB-CRC (Cyclic Redundancy Code) for detecting an error in TB, and is divided into several CBs . Each CB is equipped with a CB-CRC (Cyclic Redundancy Code) to detect CB errors. When receiving the PDSCH, the UE transmits an ACK if no error is detected in the TB-CRC, and transmits a NACK when an error is detected in the TB-CRC. When the NACK is received, the base station determines that an error has occurred in the previous TB, and performs HARQ retransmission of all the CBs included in the TB. Therefore, if one CB is wrongly received in the current system, all the CBs included in the TB are retransmitted, so there is a high possibility that inefficient retransmission occurs. In order to solve this problem, CBG (Code Block Group) is constructed by grouping the CBs constituting the TB, and the success of the CBG is notified to the base station for each CBG, and the HARQ is retransmitted only for the CBGs in which the base station fails to receive.

In the 3GPP NR system, when the base station is configured to enable CBG-based transmission to the UE, additional information should be informed through the downlink control information as compared with the TB-based transmission. The additional information to be notified should tell us which CBGs have been transmitted, which CBGs should be handled differently, CBG-based communications, or TB-based communications. The present invention relates to design of downlink control information informing the above information.

In the 3GPP NR system, the UE can be configured to receive CBG-based reception from the base station, and receive additional information compared with the TB-based reception through the downlink control information. The information that should be additionally received from the base station should receive which CBGs are transmitted, which CBGs should be handled differently, and CBG-based or per-TB-based communications. The present invention relates to design of downlink control information including the information received by the terminal and operation of the terminal accordingly.

The objects that can be achieved by the present invention are not limited to those specifically described herein.

In order to solve the above technical problem, in a technical aspect of the present invention, a base station designates all CBGIF (CBG information fields) included in downlink control information (for example, DCI) (or 0) as an implicit NDI (New Data Indication). In this case, the MCS field included in the downlink control information is used to inform the modulation order and the TB size. In contrast, if both 0 and 1 are included in the CBGIF included in the downlink control information transmitted to the mobile station, 2 bits of the MCS field is used to inform the modulation order, and 1 bit among the remaining bits of the MCS field indicates the NDI A base station for generating, instructing and transmitting the downlink control information, and an operation of the base station.

In order to solve the above technical problem, according to the technical aspect of the present invention, if the CBGIF (CBG information field) included in the downlink control information (for example, DCI) received from the base station is all 1 (or 0) (Or 0), and the MCS field included in the downlink control information is used to receive and interpret both the modulation order and the TB size. In contrast, if the UE includes both 0s and 1s in the CBGIF included in the downlink control information received from the base station, 2bits of the MCS field is received and interpreted as indicating the modulation order, and 1bit among the remaining bits of the MCS field is transmitted to the NDI And receiving and analyzing downlink control information for explicitly receiving and analyzing the downlink control information.

In order to solve the above technical problem, when a CBGIF (CBG information field) included in downlink control information (for example, DCI) received from a base station is all 1 (or 0) Is used for receiving and analyzing the modulation order and the TB size. If the value of the RV field included in the downlink control information is a specific value, the UE determines that it is a CBG-based transmission or a TB-based transmission if the specific value is another specific value. In contrast, if the CBGIF included in the downlink control information received from the base station includes both 0s and 1s, the UE receives and analyzes 2bits of the MCS field indicating that the modulation order is informed, and 1bit among the remaining bits of the MCS field is TB The present invention relates to a terminal for receiving and interpreting downlink control information for explicitly receiving and interpreting a TB / CBG flag indicating whether a transmission is based on a CBG or a CBG based transmission, and an operation of the terminal accordingly. The present invention also relates to a method of constructing downlink control information to be transmitted to a mobile station, a base station for generating, instructing and transmitting the downlink control information, and an operation of the base station.

According to an aspect of the present invention, when a CBGIF included in downlink control information (e.g., DCI) received from a base station includes both 0s and 1s, 2bits of the MCS field is modulated order, and one bit of the remaining bits of the MCS field is received and interpreted by the terminal for receiving and interpreting downlink control information for explicitly receiving and interpreting a buffer flushing indication (BFI) . The present invention also relates to a method of constructing downlink control information to be transmitted to a mobile station, a base station for generating, instructing and transmitting the downlink control information, and an operation of the base station.

Technical Solution According to an aspect of the present invention, there is provided a mobile station in which a terminal interprets MCS and CBGIF values included in downlink control information (for example, DCI) received from a base station according to a BFI value and an RV value And receiving and analyzing the downlink control information. The present invention also relates to a method of constructing downlink control information to be transmitted to a mobile station, a base station for generating, instructing and transmitting the downlink control information, and an operation of the base station.

In order to solve the above technical problem, in a technical aspect of the present invention, a base station transmits a CBGTI (CBG Transmission Information) field included in downlink control information (for example, DCI) (Or 0) as an implicit NDI (New Data Indication). At this time, all the bits mapped to the MCS field included in the downlink control information are transmitted in modulation order and TB size It is used to inform information. In contrast, if the CBGTI field included in the downlink control information transmitted to the mobile station includes both 0s and 1s, 2bits of the MCS field is used to inform the modulation order, and 1 bit of the remaining bits of the MCS field is used to indicate the NDI A method for constructing downlink control information for explicitly informing a base station, and a base station for generating, instructing and transmitting the downlink control information and an operation of the base station.

According to an aspect of the present invention, when all 1s (or 0s) are mapped to a CBGTI field included in downlink control information (e.g., DCI) received from a base station, 1 (or 0), and all the bits mapped to the MCS field included in the downlink control information are used for receiving and analyzing information such as modulation order and TB size. In contrast, if the UE includes both 0 and 1 in the CBGTI field included in the downlink control information received from the base station, 2 bits of the MCS field is received and interpreted as indicating modulation order, and 1 bit of the remaining bits of the MCS field is The present invention relates to a terminal for receiving and analyzing downlink control information for explicitly receiving and analyzing an NDI, and an operation of the terminal accordingly.

In order to solve the above technical problem, in a technical aspect of the present invention, if a downlink control information (for example, DCI) received from a base station includes all 1s (or 0s) in a CBGTI field, If the value of the included RV field is a specific value, the UE determines that it is a CBG-based transmission or a TB-based transmission if it is another specific value. In contrast, if the downlink control information received from the base station is a transmission including a part of CBG, the UE receives and analyzes 2 bits of the MCS field included in the downlink control information to inform the modulation order, and 1 bit among the remaining bits of the MCS field The present invention relates to a terminal for receiving and interpreting downlink control information for explicitly receiving and analyzing a TB / CBG flag indicating whether a TB-based transmission or a CBG-based transmission is performed and an operation of the terminal accordingly. The present invention also relates to a method of constructing downlink control information to be transmitted to a mobile station, a base station for generating, instructing and transmitting the downlink control information, and an operation of the base station.

According to an aspect of the present invention, when a CBGTI field included in downlink control information (for example, DCI) received from a base station includes both 0s and 1s, and 1 bit of the remaining bits of the MCS field are received and interpreted by CBGF Flushing Information (CBGFI), which informs soft-buffer flushing information, to receive and interpret the downlink control information. And the operation of the terminal accordingly. The present invention also relates to a method of constructing downlink control information to be transmitted to a mobile station, a base station for generating, instructing and transmitting the downlink control information, and an operation of the base station.

Technical Solution According to an aspect of the present invention, there is provided a method for controlling a mobile station in which a value of MCS and CBGTI included in downlink control information (for example, DCI) received from a base station varies depending on a combination of a CBGFI value and an RV value The present invention relates to a terminal for receiving and analyzing downlink control information to be analyzed and an operation of the terminal accordingly. The present invention also relates to a method of constructing downlink control information to be transmitted to a mobile station, a base station for generating, instructing and transmitting the downlink control information, and an operation of the base station.

Technical Solution According to an aspect of the present invention, there is provided a method for transmitting a downlink control information (hereinafter referred to as " downlink control information ") when a CBGTI field included in downlink control information The 1-bit NDI field value included in the 1-bit NDI field is determined to be the NDI value, and if the CBGTI field includes both 0 and 1, the 1-bit NDI field value can be determined to be the CBGFI value. If the CBGFI value is equal to the NDI value of the corresponding TB, the soft-buffer is not flushed. If the CBGFI value is different from the NDI value of the corresponding TB, the downlink The present invention relates to a terminal for receiving and interpreting control information and an operation of the terminal accordingly. The present invention also relates to a method of constructing downlink control information to be transmitted to a mobile station, a base station for generating, instructing and transmitting the downlink control information, and an operation of the base station.

It will be understood by those skilled in the art that various changes and modifications within the spirit and scope of the invention will become apparent to those skilled in the art from the following detailed description of the invention, do.

According to an embodiment of the present invention, a base station transmits downlink control information (e.g., DCI - Downlink control information) to a mobile station with a small overhead, thereby enabling efficient transmission of downlink control information, The transmission efficiency of the network can be increased. Also, the UE can improve the reception performance of the downlink control information according to the link adaptation in receiving the downlink control information of small size transmitted by the base station.

1 shows an example of a radio frame structure used in a wireless communication system.
2 shows an example of a downlink (DL) / uplink (UL) slot structure in a wireless communication system.
3 is a view for explaining a physical channel used in a 3GPP system and a general signal transmission method using the same.
FIG. 4 illustrates a radio frame structure for transmission of a synchronization signal (SS).
5 is a diagram illustrating a structure of a downlink radio frame used in an LTE system.
6 illustrates a configuration of a cell specific common reference signal.
FIG. 7 shows an example of a UL subframe structure used in a wireless communication system.
8 is a conceptual diagram illustrating a carrier aggregation (CA) technique.
FIG. 9 is a diagram for explaining Single Carrier Communication and Multiple Carrier Communication. FIG.
10 is a diagram showing an example in which a cross carrier scheduling technique is applied.
11 is a diagram illustrating a deployment scenario of a UE and a BS in an LTE and LAA service environment.
12 is a block diagram showing the configuration of a terminal and a base station according to an embodiment of the present invention.
13 is a block diagram illustrating a transmission method between a terminal and a base station.
Figure 14 shows the DCI that a CBG based communication should deliver.
Fig. 15 shows a method of reducing NDI 1 bit.
16 shows a method of reducing the TB / CBG flag by one bit.
17 shows a method of selecting a redundancy version value.
FIG. 18 shows a method of reducing BFI 1 bit.
FIG. 19 shows a method of reducing NDI 1 bit, BFI 1 bit, and TB / CBG flag 1 bit according to a preferred embodiment of the present invention.
20 shows a method of analyzing MCS and CBGIF according to BFI and RV values in a preferred embodiment of the present invention.

As used herein, terms used in the present invention are selected from general terms that are widely used in the present invention while taking into account the functions of the present invention. However, these terms may vary depending on the intention of a person skilled in the art, custom or the emergence of new technology. Also, in certain cases, there may be a term arbitrarily selected by the applicant, and in this case, the meaning thereof will be described in the description of the corresponding invention. Therefore, it is intended that the terminology used herein should be interpreted relative to the actual meaning of the term, rather than the nomenclature, and its content throughout the specification.

Throughout the specification, when a configuration is referred to as being "connected" to another configuration, it is not limited to the case where it is "directly connected," but also includes "electrically connected" do. Also, when an element is referred to as " including " a specific element, it is meant to include other elements, rather than excluding other elements, unless the context clearly dictates otherwise. In addition, the limitations of " above " or " below ", respectively, based on a specific threshold value may be appropriately replaced with "

FIG. 1 shows an example of a radio frame structure used in a wireless communication system.

Particularly, FIG. 1 (a) shows a frame structure for a frequency division duplex (FDD) used in a 3GPP LTE / LTE-A system and FIG. 1 Time division duplex (TDD) frame structure.

Referring to FIG. 1, a radio frame used in the 3GPP LTE / LTE-A system has a length of 10 ms (307200 Ts) and is composed of 10 equal sized subframes (SF). 10 subframes within one radio frame may be assigned respective numbers. Here, Ts represents the sampling time, and is represented by Ts = 1 / (2048 * 15 kHz). Each subframe is 1 ms long and consists of two slots. 20 slots in one radio frame can be sequentially numbered from 0 to 19. [ Each slot has a length of 0.5 ms. The time for transmitting one subframe is defined as a Transmission Time Interval (TTI). The time resource may be classified by a radio frame number (or a radio frame index), a subframe number (also referred to as a subframe number), a slot number (or a slot index), and the like.

The wireless frame may be configured differently according to the duplex mode. For example, in the FDD mode, since the downlink transmission and the uplink transmission are divided by frequency, the radio frame includes only one of the downlink subframe and the uplink subframe for a specific frequency band. In the TDD mode, since the downlink transmission and the uplink transmission are divided by time, the radio frame includes both the downlink subframe and the uplink subframe for a specific frequency band.

Table 1 illustrates the DL-UL configuration of subframes in a radio frame in TDD mode.

In Table 1, D denotes a downlink subframe, U denotes an uplink subframe, and S denotes a special subframe. The specific subframe includes three fields of Downlink Pilot Time Slot (DwPTS), Guard Period (GP), and UpPTS (Uplink Pilot Time Slot). DwPTS is a time interval reserved for downlink transmission, and UpPTS is a time interval reserved for uplink transmission. Table 2 illustrates the configuration of the singular frames.

2 illustrates an example of a downlink (DL) / uplink (UL) slot structure in a wireless communication system. In particular, Figure 2 shows the structure of the resource grid of the 3GPP LTE / LTE-A system. There is one resource grid per antenna port. Referring to FIG. 2, a slot includes a plurality of OFDM symbols in a time domain and a plurality of resource blocks (RB) in a frequency domain. The OFDM symbol also means one symbol period. Referring to FIG. 2, a signal transmitted in each slot may be expressed as a resource grid consisting of N ^{DL / UL} _RB * N ^RB _sc subcarriers and N ^{DL / UL} _symb OFDM symbols. have. Here, N ^DL _RB represents the number of resource blocks (RBs) in the downlink slot, and N ^UL _RB represents the number of _RBs in the UL slot. N ^DL _RB and N ^UL _RB depend on the DL transmission bandwidth and the UL transmission bandwidth, respectively. N ^DL _symb denotes the number of OFDM symbols in the downlink slot, and N ^UL _symb denotes the number of OFDM symbols in the UL slot. N ^RB _sc represents the number of subcarriers constituting one RB. The OFDM symbol may be referred to as an OFDM symbol, an SC-FDM (Single Carrier Frequency Division Multiplexing) symbol, or the like according to a multiple access scheme. The number of OFDM symbols included in one slot can be variously changed according to the channel bandwidth and the length of the cyclic prefix (CP). For example, in the case of a normal CP, one slot includes 7 OFDM symbols

In the case of an extended CP, one slot includes six OFDM symbols. Although FIG. 2 illustrates a subframe in which one slot is composed of seven OFDM symbols for convenience of description, embodiments of the present invention may be applied to subframes having a different number of OFDM symbols in a similar manner. Referring to FIG. 2, each OFDM symbol includes N ^{DL / UL} _RB * N ^RB _sc subcarriers in the frequency domain. The type of subcarrier may be a data subcarrier for data transmission, a reference signal subcarrier for transmission of a reference signal, a null subcarrier for a guard band or a direct current (DC) ≪ / RTI > The DC component is mapped to a carrier frequency (f ₀ ) in an OFDM signal generation process or a frequency up-conversion process. The carrier frequency is also referred to as the center frequency (f _c ).

One RB is defined as N ^{DL / UL} _symb consecutive OFDM symbols in the time domain (for example, seven), and N ^RB _scrambled (e.g., twelve) consecutive subcarriers in the frequency domain . For reference, a resource composed of one OFDM symbol and one subcarrier is referred to as a resource element (RE) or tone. Therefore, one RB consists of N ^{DL / UL} _symb * N ^RB _sc resource elements. Each resource element in the resource grid can be uniquely defined by an index pair (k, 1) in one slot. k is an index assigned from 0 to N ^{DL / UL} _RB * N ^RBsc -1 in the frequency domain, and 1 is an index assigned from 0 to N ^{DL / UL} _symb -1 in the time domain.

One RB is mapped to one physical resource block (PRB) and one virtual resource block (VRB). The PRB is defined as N ^{DL / UL} _symb (e.g., 7) consecutive OFDM symbols or SC-FDM symbols in the time domain, and N ^RB _scrambled (e.g., twelve) Is defined by the subcarrier. Therefore, one PRB consists of N ^{DL / UL} _symb * N ^RB _sc resource elements. Two RBs, one in each of two slots of the subframe occupying N ^RB _sc consecutive identical subcarriers in one subframe, are called a PRB pair. The two RBs constituting the PRB pair have the same PRB number (or PRB index).

In order for the UE to receive a signal from the eNB or to transmit a signal to the eNB, the time / frequency synchronization of the UE should be synchronized with the time / frequency synchronization of the eNB. since it can determine the time and frequency parameters necessary for the UE to perform the demodulation of the DL signal and the transmission of the UL signal at the correct time, as long as it is synchronized with the eNB.

3 is a view for explaining a physical channel used in a 3GPP system and a general signal transmission method using the same.

The terminal performs an initial cell search operation such as synchronizing with a base station when power is increased or newly enters a cell (S301). To this end, the terminal receives a primary synchronization channel (P-SCH) and a secondary synchronization channel (S-SCH) from a base station and synchronizes with the base station and acquires information such as a cell ID have. Then, the terminal can receive the physical broadcast channel from the base station and acquire the in-cell broadcast information. Meanwhile, the UE can receive the downlink reference signal (DL RS) in the initial cell search step to check the downlink channel state.

Upon completion of the initial cell search, the UE receives more detailed system information by receiving a Physical Downlink Control Channel (PDCCH) and a Physical Downlink Control Channel (PDSCH) according to the information on the PDCCH (S302).

On the other hand, if the base station is initially connected or there is no radio resource for signal transmission, the terminal can perform a random access procedure (RACH) on the base station (steps S303 to S306). To this end, the UE transmits a specific sequence through a Physical Random Access Channel (PRACH) (S303 and S305), and receives a response message for the preamble on the PDCCH and the corresponding PDSCH S304 and S306). In case of the contention-based RACH, a contention resolution procedure can be additionally performed.

The UE having performed the procedure described above transmits PDCCH / PDSCH reception (S307) and physical uplink shared channel (PUSCH) / physical uplink control channel Control Channel, PUCCH) (S308). In particular, the UE receives downlink control information (DCI) through the PDCCH. Here, the DCI includes control information such as resource allocation information for the UE, and formats are different according to the purpose of use.

Meanwhile, the control information that the UE transmits to the base station through the uplink or receives from the base station includes a downlink / uplink ACK / NACK signal, a channel quality indicator (CQI), a precoding matrix index (PMI) ) And the like. In the case of the 3GPP LTE system, the UE can transmit control information such as CQI / PMI / RI as described above through PUSCH and / or PUCCH.

FIG. 4 illustrates a radio frame structure for transmission of a synchronization signal (SS). In particular, FIG. 4 illustrates a radio frame structure for transmission of a synchronous signal and a PBCH in a frequency division duplex (FDD). FIG. 4A illustrates a radio frame in a normal CP (normal cyclic prefix) SS and PBCH. FIG. 4 (b) shows transmission positions of SS and PBCH in a radio frame configured with an extended CP.

The UE obtains time and frequency synchronization with the cell when it is powered on or newly connected to the cell, and performs cell search such as detecting the physical cell identity N ^cell _ID of the cell cell search procedure. To this end, the UE receives a synchronization signal, for example, a primary synchronization signal (PSS) and a secondary synchronization signal (SSS) from the eNB, synchronizes with the eNB, , ID) can be obtained.

Referring to FIG. 4, the SS will be described in more detail as follows. SS is divided into PSS and SSS. PSS is used to obtain time domain synchronization and / or frequency domain synchronization such as OFDM symbol synchronization, slot synchronization, and the like. SSS is used for frame synchronization, cell group ID, and / or cell CP configuration Information). Referring to FIG. 4, the PSS and the SSS are transmitted in two OFDM symbols of each radio frame, respectively. In order to facilitate inter Radio Access Technology ("RAT") measurement, the SS considers 4.6 ms, which is the Global System for Mobile communication (GSM) frame length, in the first slot of subframe 0 and the first slot of subframe 5 Respectively. Specifically, the PSS is transmitted in the last OFDM symbol of the first slot of the subframe 0 and the last OFDM symbol of the first slot of the subframe 5, respectively, and the SSS is transmitted from the second OFDM symbol at the end of the first slot of the subframe 0, Lt; RTI ID = 0.0 > OFDM < / RTI > The boundary of the corresponding radio frame can be detected through the SSS. The PSS is transmitted in the last OFDM symbol of the slot and the SSS is transmitted in the OFDM symbol immediately before the PSS. SS's transmit diversity scheme uses only a single antenna port and is not defined in the standard. That is, a single antenna port transmission or a UE transparent transmission scheme (e.g., Precoding Vector Switching (PVS), Time Switched Diversity (TSTD), Cyclic Delay Diversity (CDD)) can be used for SS transmission diversity .

The SS can represent a total of 504 unique physical layer cell IDs through a combination of three PSSs and 168 SSs. In other words, the physical layer cell IDs are allocated to 168 physical-layer cell-identifier groups, each group including three unique identifiers, such that each physical-layer cell ID is part of only one physical-layer cell- . Thus, the physical layer cell ID _{^{N cell ID = 3N (1)}} ID + N (2) ID is a physical-layer cell - the range of 0 [identifier group to the 167 number N ⁽¹⁾ _ID and the physical-layer cell - a unique number N ⁽²⁾ _ID of 0 to 2 indicating the physical-layer identifier in the identifier group. The UE may detect the PSS to know one of the three unique physical-layer identifiers and may detect the SSS to identify one of the 168 physical layer cell IDs associated with the physical-layer identifier. A ZC (Zadoff-Chu) sequence of length 63 is defined in the frequency domain and used as the PSS.

Referring to FIG. 4, since the PSS is transmitted every 5 ms, the UE can detect that the corresponding subframe is one of the subframe 0 and the subframe 5 by detecting the PSS. However, I do not know what it is. Therefore, the UE can not recognize the boundary of the radio frame only by the PSS. That is, frame synchronization can not be obtained with only PSS. The UE detects an SSS transmitted twice in one radio frame but transmitted as a different sequence and detects the boundary of the radio frame.

5 is a diagram illustrating a control channel included in a control region of one subframe in a downlink radio frame.

Referring to FIG. 5, a subframe is composed of 14 OFDM symbols. According to the subframe setting, the first to third OFDM symbols are used as a control region and the remaining 13 to 11 OFDM symbols are used as a data region. In the figure, R1 to R4 represent a reference signal (RS) or pilot signal for antennas 0 to 3. The RS is fixed in a constant pattern in the subframe regardless of the control region and the data region. The control channel is allocated to a resource to which the RS is not allocated in the control region, and the traffic channel is also allocated to the resource to which the RS is not allocated in the data region. Control channels allocated to the control region include a Physical Control Format Indicator CHannel (PCFICH), a Physical Hybrid-ARQ Indicator CHannel (PHICH), and a Physical Downlink Control Channel (PDCCH).

The PCFICH informs the UE of the number of OFDM symbols used in the PDCCH for each subframe as a physical control format indicator channel. The PCFICH is located in the first OFDM symbol and is set prior to the PHICH and PDCCH. The PCFICH is composed of four REGs (Resource Element Groups), and each REG is distributed in the control area based on the cell ID (Cell IDentity). One REG is composed of four REs (Resource Elements). RE denotes a minimum physical resource defined by one subcarrier x one OFDM symbol. The PCFICH value indicates a value of 1 to 3 or 2 to 4 depending on the bandwidth and is modulated by Quadrature Phase Shift Keying (QPSK).

The PHICH is used as a physical HARQ (Hybrid Automatic Repeat and Request) indicator channel to carry HARQ ACK / NACK for uplink transmission. That is, the PHICH indicates a channel through which DL ACK / NACK information for UL HARQ is transmitted. The PHICH consists of one REG and is cell-specific scrambled. The ACK / NACK is indicated by 1 bit and is modulated by BPSK (Binary Phase Shift Keying). The modulated ACK / NACK is spread with a spreading factor (SF) = 2 or 4. A plurality of PHICHs mapped to the same resource constitute a PHICH group. The number of PHICHs multiplexed into the PHICH group is determined by the number of spreading codes. The PHICH (group) is repetitized three times to obtain the diversity gain in the frequency domain and / or the time domain.

The PDCCH is allocated to the first n OFDM symbols of the subframe as the physical downlink control channel. Here, n is an integer of 1 or more and is indicated by the PCFICH. The PDCCH consists of one or more CCEs. The PDCCH notifies each terminal or group of terminals of information related to resource allocation of a paging channel (PCH) and a downlink-shared channel (DL-SCH), an uplink scheduling grant, and HARQ information. A paging channel (PCH) and a downlink-shared channel (DLSCH) are transmitted on the PDSCH. Therefore, the BS and the MS generally transmit and receive data via the PDSCH, except for specific control information or specific service data.

PDSCH data is transmitted to a terminal (one or a plurality of terminals), and information on how the terminals receive and decode PDSCH data is included in the PDCCH and transmitted. For example, if a particular PDCCH is CRC masked with an RNTI (Radio Network Temporary Identity) of "A ", and a DCI format called " C" Assume that information on data to be transmitted using information (e.g., transport block size, modulation scheme, coding information, etc.) is transmitted through a specific subframe. In this case, the UE in the cell monitors the PDCCH using its RNTI information, and if there is more than one UE having the "A" RNTI, the UEs receive the PDCCH, B "and" C ".

FIG. 6 illustrates the configuration of a cell specific common reference signal. In particular, Figure 6 illustrates a CRS structure for a 3GPP LTE system supporting up to four antennas.

[Equation 1]

Where k is a subcarrier index, 1 is an OFDM symbol index, p is an antenna port number, and ^{Nmax and DL} _RB represent the largest downlink bandwidth configuration, expressed as an integer multiple of N ^RB _sc .

The variables v and v _shift define positions in the frequency domain for different RSs, and v is given by

&Quot; (2) "

Where n _s is the slot number in the radio frame and the cell specific frequency transition is given by:

&Quot; (3) "

Referring to FIG. 6 and Equations 1 and 2, the current 3GPP LTE / LTE-A standard defines a cell-specific CRS used for demodulation and channel measurement among the various RSs defined in the corresponding system, To be transmitted over the entire downlink band. Also, in the 3GPP LTE / LTE-A system, the cell-specific CRS is used for demodulation of the downlink data signal, and thus is transmitted every antenna port for downlink transmission.

Meanwhile, the cell-specific CRS can be used not only for channel state measurement and data demodulation, but also for tracking after the UE acquires time synchronization and frequency synchronization of a carrier used for communication with the UE, It is also used for tracking.

FIG. 7 shows an example of a UL subframe structure used in a wireless communication system.

Referring to FIG. 7, the UL subframe may be divided into a control domain and a data domain in the frequency domain. One or several physical uplink control channels (PUCCHs) may be assigned to the control region to carry uplink control information (UCI). One or several physical uplink shared channels (PUSCHs) may be allocated to the data area of the UL subframe to carry user data.

In the UL subframe, subcarriers far away from each other based on a DC (Direct Current) subcarrier are used as a control region. In other words, the subcarriers located at both ends of the UL transmission bandwidth are allocated for transmission of the UL control information. The DC subcarrier is a component that is left unused for signal transmission and is mapped to the carrier frequency f ₀ in the frequency up conversion process. In one subframe, the PUCCH for one UE is allocated to an RB pair belonging to resources operating at one carrier frequency, and RBs belonging to the RB pair occupy different subcarriers in two slots. The PUCCH allocated as described above is expressed as the RB pair allocated to the PUCCH is frequency hopped at the slot boundary. However, when frequency hopping is not applied, the RB pairs occupy the same subcarrier.

The PUCCH may be used to transmit the following control information.

- SR (Scheduling Request): Information used for requesting uplink UL-SCH resources. OOK (On-Off Keying) method.

- HARQ-ACK: A response to the PDCCH and / or a response to a downlink data packet (eg, codeword) on the PDSCH.

Indicates whether PDCCH or PDSCH has been successfully received. In response to a single downlink codeword, one bit of HARQACK is transmitted and two bits of HARQ-ACK are transmitted in response to two downlink codewords. The HARQ-ACK response includes positive ACK (simply ACK), negative ACK (NACK), DTX (Discontinuous Transmission) or NACK / DTX. Here, the term HARQ-ACK is mixed with HARQ ACK / NACK and ACK / NACK.

- CSI (Channel State Information): Feedback information for the downlink channel. Multiple Input Multiple Output (MIMO) -related feedback information includes RI (Rank Indicator) and PMI (Precoding Matrix Indicator).

Hereinafter, a carrier aggregation technique will be described. 8 is a conceptual diagram illustrating carrier aggregation.

Carrier aggregation is a technique in which a radio communication system uses a frequency block or a (logical sense) cell composed of uplink resources (or component carriers) and / or downlink resources (or component carriers) Which is used as a single large logical frequency band. Hereinafter, the term "component carrier" is used for the convenience of description.

Referring to FIG. 8, the total system bandwidth (System BW) has a bandwidth of 100 MHz as a logical bandwidth. The total system bandwidth includes five component carriers, each of which has a bandwidth of up to 20 MHz. A component carrier comprises one or more contiguous subcarriers physically contiguous. In FIG. 8, each of the component carriers is shown to have the same bandwidth, but this is merely an example, and each component carrier may have a different bandwidth. In addition, although each component carrier is shown as being adjacent to each other in the frequency domain, this figure is shown in a logical concept, wherein each component carrier may physically be adjacent to or spaced from one another.

The center frequency may use different common carriers for each component carrier or common for physically contiguous component carriers. For example, assuming that all of the component carriers are physically adjacent in FIG. 8, the center carrier A can be used. Further, assuming that the respective component carriers are not physically adjacent to each other, the center carrier A, the center carrier B, and the like can be used separately for each component carrier.

In this specification, the component carrier may correspond to the system band of the legacy system. By defining a component carrier based on a legacy system, it is possible to provide backward compatibility and system design in a wireless communication environment in which an evolved terminal and a legacy terminal coexist. In one example, if the LTE-A system supports carrier aggregation, each component carrier may correspond to the system band of the LTE system. In this case, the component carrier may have any of the following bandwidths: 1.25, 2.5, 5, 10, or 20 Mhz.

The frequency band used for communication with each terminal when the entire system band is expanded by carrier aggregation is defined in units of component carriers. Terminal A can use 100 MHz, which is the entire system band, and performs communication using all five component carriers. The terminals B1 to B5 can use only a 20 MHz bandwidth and perform communication using one component carrier. Terminals C ₁ and C ₂ can use a 40 MHz bandwidth and each communicate using two component carriers. The two component carriers may be logically / physically adjacent or non-contiguous. The terminal C ₁ shows a case in which two non-adjacent component carriers are used and the terminal C ₂ shows a case in which two adjacent component carriers are used.

In the LTE system, one downlink component carrier and one uplink component carrier are used, while in the LTE-A system, a plurality of component carriers can be used as shown in FIG. A combination of a downlink component carrier or a corresponding downlink component carrier and a corresponding uplink component carrier may be referred to as a cell and a corresponding relationship between a downlink component carrier and an uplink component carrier may be indicated through system information .

At this time, the scheme of scheduling the data channel by the control channel may be classified into a link carrier scheduling method and a cross carrier scheduling method.

More specifically, link carrier scheduling schedules data channels only through the particular component carrier, such as existing LTE systems that use a single component carrier, over a particular component carrier. That is, the downlink grant / uplink grant transmitted to the PDCCH region of the downlink component carrier of a specific component carrier (or specific cell) can be scheduled only for the PDSCH / PUSCH of the cell to which the corresponding downlink component carrier belongs. That is, the search space, which is an area for attempting to detect the downlink grant / uplink grant, exists in the PDCCH region of the cell where the PDSCH / PUSCH to be scheduled is located.

On the other hand, in the cross carrier scheduling, when a control channel transmitted through a primary component carrier (Primary CC) using a Carrier Indicator Field (CIF) is transmitted through the main component carrier or through another component carrier Schedules the channel. In other words, a monitored cell (Monitored Cell or Monitored CC) of the cross-carrier scheduling is set, and the downlink grant / uplink grant transmitted in the PDCCH region of the monitored cell is set to PDSCH / PUSCH of a cell set to be scheduled in the corresponding cell Scheduling. That is, a search area for a plurality of component carriers is present in a PDCCH area of a cell to be monitored. Among the plurality of cells, system information is transmitted, an initial access attempt is made, and the PCell is set by transmission of uplink control information. The PCell is a downlink main component carrier and an uplink main component carrier corresponding to the downlink main component carrier .

9 is a diagram for explaining single carrier communication and multiple carrier communication. Particularly, FIG. 9A shows a subframe structure of a single carrier and FIG. 9B shows a subframe structure of multiple carriers.

Referring to FIG. 9A, a general wireless communication system performs data transmission or reception (in a frequency division duplex (FDD) mode) through one DL band and one UL band corresponding thereto , A radio frame is divided into an uplink time unit and a downlink time unit in a time domain and data transmission or reception is performed through an uplink / downlink time unit (time division duplex , TDD) mode). However, in recent wireless communication systems, introduction of a carrier aggregation technique using a larger UL / DL bandwidth by collecting a plurality of UL and / or DL frequency blocks in order to use a wider frequency band is being discussed. Carrier aggregation is an orthogonal frequency division multiplexing (OFDM) scheme that performs DL or UL communication by putting a fundamental frequency band divided into a plurality of orthogonal subcarriers on one carrier frequency in that DL or UL communication is performed using a plurality of carrier frequencies division multiplexing system. Hereinafter, each of the carriers collected by carrier aggregation is referred to as a component carrier (CC). Referring to FIG. 9 (b), three 20 MHz CCs can be grouped into UL and DL, respectively, so that a bandwidth of 60 MHz can be supported. Each CC may be adjacent or non-adjacent to one another in the frequency domain. FIG. 9B shows a case where the bandwidth of the UL CC and the bandwidth of the DL CC are the same and symmetric, but the bandwidth of each CC can be determined independently. Asymmetric carrier aggregation in which the number of UL CCs is different from the number of DL CCs is also possible. A DL / UL CC specific to a particular UE may be referred to as a configured serving UL / DL CC in a particular UE.

The eNB may be used to communicate with the UE by activating some or all of the serving CCs configured in the UE, or by deactivating some CCs. The eNB can change the CC to be activated / deactivated, and can change the number of CCs to be activated / deactivated. When the eNB allocates a CC available for the UE in a cell-specific or UE-specific manner, at least one of the assigned CCs is used, as long as the CC allocation for the UE is not completely reconfigured or the UE does not perform a handover. One is not disabled. A CC that is not deactivated is referred to as a primary CC (PCC), and a CC that can be freely activated / deactivated by the eNB is called a secondary CC (SCC), unless it is a full reconfiguration of the CC assignment to the UE It is called. PCC and SCC may be distinguished based on control information. For example, specific control information may be set to be transmitted and received only via a specific CC, which may be referred to as PCC and the remaining CC (s) as SCC (s).

Meanwhile, 3GPP LTE (-A) uses the concept of a cell to manage radio resources. A cell is defined as a combination of DL resources and UL resources, that is, a combination of DL CC and UL CC. A cell may consist of DL resources alone, or a combination of DL resources and UL resources. If carrier aggregation is supported, the linkage between the carrier frequency of the DL resource (or DL CC) and the carrier frequency of the UL resource (or UL CC) . For example, a combination of a DL resource and a UL resource can be indicated by linkage of System Information Block Type 2 (SIB2). Here, the carrier frequency means a center frequency of each cell or CC. In the following,

a cell operating on a frequency is referred to as a primary cell or a PCC and a cell operating on a secondary frequency (or SCC) is referred to as a secondary cell (SCell) It is called. The carrier corresponding to PCell in the downlink is referred to as a downlink primary CC (DL PCC), and the carrier corresponding to PCell in the uplink is referred to as a UL primary CC (DL PCC). SCell refers to a cell that is configurable after a Radio Resource Control (RRC) connection is established and can be used to provide additional radio resources. Depending on the capabilities of the UE, a SCell may form together with the PCell a set of serving cells for the UE. The carrier corresponding to the SCell in the downlink is referred to as DL secondary CC (DL SCC), and the carrier corresponding to the SCell in the uplink is referred to as UL secondary CC (UL SCC)

do. For UEs that are in the RRC_CONNECTED state but no carrier aggregation is set or that do not support carrier aggregation, there is only one serving cell consisting of only PCell.

As previously mentioned, the term cell used in carrier aggregation is distinguished from the term cell, which refers to a geographical area in which a communication service is provided by a single eNB or a group of antennas. In order to distinguish between a cell designating a certain geographical area and a cell of carrier aggregation, a carrier aggregation cell is referred to as a CC and a cell in a geographical area is referred to as a cell. Quot;

In the existing LTE / LTE-A system, when multiple CCs are used together, it is assumed that the UL / DL frame time synchronization of the SCC coincides with the time synchronization of the PCC, assuming that the CCs that are not so far away in the frequency domain are clustered. However, there is a possibility that a plurality of CCs belonging to different frequency bands or spaced apart from each other in frequency, that is, a plurality of CCs having different propagation characteristics, may be gathered in the future. In this case, assuming that the time synchronization of the PCC and the time synchronization of the SCC are the same as in the conventional case, the synchronization of the DL / UL signal of the SCC may be seriously adversely affected.

Meanwhile, in the case of the LCT CC, among the radio resources operating in the LCT CC, radio resources available for transmission / reception of physical uplink / downlink channels and radio resources available for transmission / reception of physical uplink / The resources, as described above, are predetermined. In other words, the LCT CC is not configured to carry physical channels / signals through arbitrary time frequency in arbitrary time resources, but may be configured to transmit the physical channel / Signal should be configured to carry. For example, the physical downlink control channels may be configured only in the first OFDM symbol (s) of the OFDM symbols in the DL subframe, and the PDSCH may include the first OFDM symbol (s) that are likely to be mapped physical downlink control channels. Lt; / RTI > As another example, the CRS (s) corresponding to the antenna port (s) of the eNB are transmitted every subframe in the REs shown in Fig. 6 over the entire band regardless of the DL BW of the eNB. Accordingly, when the number of antenna ports of the eNB is 1, REs indicated by '0' in FIG. 6 are '0', '1', '2' and ' 3 'can not be used for other downlink signal transmission. In addition, there are various constraints on the composition of the LCT CC, and these constraints are greatly increased as the communication system develops. Some of these constraints arise because of the level of communication technology at the time the constraint is created, and there are some constraints that are unnecessary as communication technology develops, and constraints of existing and new technologies for the same purpose It may be present at the same time. As the constraints become so large, the constraints introduced for the development of the communication system are making the wireless resources of the CC ineffective. Therefore, the introduction of NCT CC, which can be constructed according to the simplified constraints rather than the existing constraints, is free from the constraints that are unnecessary according to the development of the communication technology. Since the NCT CC is not constructed according to the constraints of the existing system, it can not be recognized by the UE implemented according to the existing system. Hereinafter, UEs which are implemented according to the existing system and can not support NCT CC are called legacy UEs, and UEs implemented to support NCT CCs are called NCT UEs.

It is considered that NCT CC will be used as SCC in LTE-A system in the future. Since the NCT CC does not consider use by the legacy UE, the legacy UE does not need to perform cell search, cell selection, cell reselection, etc. in the NCT CC. If the NCT CC is not used as a PCC and the NCT CC is used only as an SCC, unnecessary constraints on the SCC can be reduced compared to an existing LCT CC that can be used as a PCC, enabling more efficient use of the CC. However, the time / frequency synchronization of the NCT CC may not coincide with the synchronization of the PCC. Even if the time / frequency synchronization of the NCT CC is obtained once, the time / frequency synchronization may be changed according to the change of the communication environment. An RS in which time synchronization and / or frequency synchronization can be used for tracking is required. An RS is also needed to allow the UE to detect the NCT CC in the neighbor cell search process. CRS can be used for purposes such as time / frequency synchronization of NCT CC and neighbor cell search using NCT CC. The CRS may be configured in the NCT CC in the same manner as in the existing LTE / LTE-A system shown in FIG. 6 and may have a smaller density in the time axis or frequency axis than the existing LTE / LTE- It may be configured in the NCT CC.

In the present invention, it is proposed that the CRS on the NCT CC is configured to have a lower density on the time axis than the CRS on the LCT CC of the existing LTE / LTE-A system. Accordingly, in the present invention, the NCT CC includes a constraint condition that the CRS is configured in the corresponding CC for every DL subframe, a constraint condition that the CRS is configured in the CC for each antenna port of the eNB, a predetermined number of OFDM It may not satisfy at least one of the constraint conditions that the symbol should be reserved for transmission of the control channel such as the PDCCH over the frequency band of the corresponding CC. For example, on the NCT CC, a CRS may be configured for every predetermined number (> 1) of subframes, not every subframe. Or, on the NCT CC, only the CRS for one antenna port (e.g., antenna port 0) can be configured regardless of the number of antenna ports of the eNB. The CRS of the present invention may not be used for data demodulation unlike the existing CRS shown in FIG. Therefore, instead of the existing CRS used for channel state measurement and demodulation, a tracking RS is newly defined for tracking of time synchronization and / or frequency synchronization, and the tracking RS is added to some subframes and / or some frequency resources on the NCT CC Lt; / RTI > Alternatively, the PDSCH may be configured in the leading OFDM symbols on the NCT CC, the PDCCH may be configured in the existing PDSCH region other than the initial OFDM symbols, or the PDCCH may be configured using some frequency resources. Hereinafter, unlike the existing LTE / LTE-A system, unlike the existing LTE / LTE-A system, the RSs transmitted in some subframes can be used in common by any UE regardless of the name, such as time synchronization and / or frequency synchronization of the NCT CC, RS (common RS, CRS).

10 is a diagram showing an example in which a cross carrier scheduling technique is applied. In particular, in FIG. 10, the number of allocated cells (or component carriers or component carriers) is three and the cross carrier scheduling technique is performed using CIF as described above. Here, it is assumed that the downlink cell # 0 is a downlink main component carrier (i.e., a primary cell, PCell) and the remaining component carriers # 1 and # 2 are subsidiary components (i.e., a secondary cell, SCell).

In the present invention, an effective management method of uplink resources for a main component carrier (primary component carrier, primary cell or PCell) or a subsidiary component carrier (secondary component carrier or secondary cell or SCell) during a carrier aggregation operation I suggest. Hereinafter, the case where the terminal operates by merging two component carriers is explained, but it is obvious that the present invention can also be applied to the case of merging three or more component carriers.

11 is a diagram illustrating a deployment scenario of a UE and a BS in an LTE and LAA service environment.

In the frequency band targeted by the LAA service environment, the wireless communication distance is not long due to the high frequency characteristics. In consideration of this, the deployment scenario between the terminal and the base station in the environment where the existing LTE-licensed service and the LAA service coexist is the overlay model shown on the left side of FIG. 11 and the overlay model shown in the right side of FIG. or a co-located model.

In the case of the overlay model shown in the left side of FIG. 11, the macro eNB performs wireless communication with the X terminal and the X 'terminal in the macro area 32 using a licensed carrier, and a plurality of RRHs and an X2 interface Lt; / RTI > Each RRH may perform wireless communication with an X terminal or an X 'terminal in a certain area 31 using an unlicensed carrier. In this case, there is no mutual interference between the macro eNB and the RRH. However, in order to use the LAA service as an auxiliary downlink channel of the LTE-licensed service through carrier aggregation, an X2 interface between the macro eNB and the RRH A fast data exchange should be made.

In the case of the co-located model shown on the right-hand side of FIG. 11, the pico / femto eNB can perform wireless communication with the Y terminal simultaneously using an authorized carrier and an unauthorized carrier. However, the use of the LTE service and the LAA service together is considered in the downlink data transmission. In this case, coverage for LTE service and coverage for LAA service may differ depending on frequency band, transmission power, and the like.

A terminal according to an embodiment of the present invention can be implemented by various types of wireless communication devices or computing devices that are guaranteed to be portable and mobility.

The base station according to the embodiment of the present invention controls and manages a cell (for example, a macro cell, a femtocell, a picocell, etc.) corresponding to a service area and transmits a signal, channel designation, channel monitoring, Can be performed.

12 is a block diagram showing the configuration of a terminal and a base station according to an embodiment of the present invention.

As shown, a terminal 100 according to an embodiment of the present invention may include a processor 110, a communication module 120, a memory 130, a user interface unit 140, and a display unit 150 have.

First, the processor 110 may execute various commands or programs, and may process data inside the terminal 100. [ In addition, the processor 100 can control the entire operation including each unit of the terminal 100, and can control data transmission / reception between the units.

Next, the communication module 120 may be an integrated module that performs wireless communication using a wireless communication network and wireless LAN connection using a wireless LAN. To this end, the communication module 120 may include a plurality of network interface cards such as the cellular communication interface cards 121 and 122 and the wireless LAN interface card 123, either internally or externally. 12, the communication module 120 is shown as an integrated integrated module, but each network interface card may be independently arranged according to the circuit configuration or use, unlike in FIG.

The cellular communication interface card 121 according to the first frequency band transmits and receives a radio signal with at least one of the base station 200, the external device, and the server using the mobile communication network, Band cellular communication service. Here, the wireless signal may include various types of data or information such as a voice call signal, a video call signal, or a text / multimedia message.

According to an embodiment of the present invention, the cellular communication interface card 121 by the first frequency band may include at least one NIC module using the LTE-Licensed frequency band. According to an embodiment of the present invention, at least one NIC module performs cellular communication with at least one of the base station 200, the external device, and the server independently in accordance with the cellular communication standard or protocol of the frequency band supported by the corresponding NIC module . The cellular communication interface card 121 may operate only one NIC module at a time or may operate a plurality of NIC modules at the same time according to the performance and requirements of the terminal 100. [

The cellular communication interface card 122 in the second frequency band transmits and receives a radio signal to and from a base station 200, an external device, and a server using a mobile communication network, Band cellular communication service. According to an embodiment of the present invention, the cellular communication interface card 122 by the second frequency band may include at least one NIC module using the LTE-Unlicensed frequency band. For example, the LTE-Unlicensed frequency band may be a band of 2.4 GHz or 5 GHz. According to an embodiment of the present invention, at least one NIC module performs cellular communication with at least one of the base station 200, the external device, and the server independently in accordance with the cellular communication standard or protocol of the frequency band supported by the corresponding NIC module . The cellular communication interface card 122 may operate only one NIC module at a time or may operate a plurality of NIC modules at the same time according to the performance and requirements of the terminal 100. [

The wireless LAN interface card 123 according to the second frequency band transmits and receives a radio signal to at least one of the base station 200, the external device, and the server through the wireless LAN connection, Band wireless LAN service. According to an embodiment of the present invention, the wireless LAN interface card 123 according to the second frequency band may include at least one NIC module using the wireless LAN frequency band. For example, the WLAN frequency band may be an unlicensed radio band such as a band of 2.4 GHz or 5 GHz. According to an embodiment of the present invention, at least one NIC module performs wireless communication with at least one of the base station 200, the external device, and the server independently in accordance with a wireless LAN standard or protocol of a frequency band supported by the corresponding NIC module . The wireless LAN interface card 123 may operate only one NIC module at a time or may operate a plurality of NIC modules at the same time according to the performance and requirements of the terminal 100. [

According to an embodiment of the present invention, the processor 110 transmits information on whether or not the wireless LAN communication service of the second frequency band is available through the cellular communication channel of the first frequency band with the base station 200, Information on the period of time. Here, the information on the predetermined period is information set for receiving the downlink data from the base station 200 through the cellular communication channel of the second frequency band.

In addition, according to an embodiment of the present invention, since the base station 200 supports a wireless LAN communication service, the processor 110 can receive a predetermined signal from the base station 200 through a wireless LAN communication channel of a second frequency band And receives the base station coexistence message including information on the period.

In addition, according to an embodiment of the present invention, the processor 110 may be configured to transmit, in response to the received base station coexistence message, The terminal transmits a terminal coexistence message including information on a predetermined period according to a standard or protocol specified in the wireless LAN communication service of the second frequency band.

Also, according to an embodiment of the present invention, the processor 110 receives downlink data from the base station 200 for a predetermined period through a cellular communication channel of a second frequency band.

Next, the memory 130 stores a control program used in the terminal 100 and various data corresponding thereto. The control program may include a predetermined program required for the terminal 100 to perform wireless communication with at least one of the base station 200, the external device, and the server.

Next, the user interface 140 includes various types of input / output means provided in the terminal 100. That is, the user interface 140 can receive user input using various input means, and the processor 110 can control the terminal 100 based on the received user input. In addition, the user interface 140 may perform output based on instructions of the processor 110 using various output means.

Next, the display unit 150 outputs various images on the display screen. The display unit 150 may output various display objects such as a content executed by the processor 110 or a user interface based on a control command of the processor 110. [

12, the base station 200 according to an exemplary embodiment of the present invention may include a processor 210, a communication module 220, and a memory 230. In addition,

First, the processor 210 may execute various commands or programs and may process data within the base station 200. In addition, the processor 210 can control the entire operation including each unit of the base station 200, and can control data transmission / reception between the units.

Next, the communication module 220 may be an integrated module for performing mobile communication using a mobile communication network and wireless LAN connection using a wireless LAN, such as the communication module 120 of the terminal 100 described above. To this end, the communication module 120 may include a plurality of network interface cards, such as the cellular communication interface cards 221 and 222 and the wireless LAN interface card 223, either internally or externally. 12, the communication module 220 is shown as an integrated integration module, but each network interface card may be independently arranged according to the circuit configuration or use, unlike in FIG.

The cellular communication interface card 221 according to the first frequency band transmits and receives a radio signal to at least one of the terminal 100, the external device, and the server using the mobile communication network, And provides cellular communication service by one frequency band. Here, the wireless signal may include various types of data or information such as a voice call signal, a video call signal, or a text / multimedia message.

According to an embodiment of the present invention, the cellular communication interface card 221 by the first frequency band may include at least one NIC module using the LTE-Licensed frequency band. According to an embodiment of the present invention, the at least one NIC module can perform cellular communication with at least one of the terminal 100, the external device, and the server independently according to the cellular communication standard or protocol of the frequency band supported by the corresponding NIC module. Can be performed. The cellular communication interface card 221 may operate only one NIC module at a time or may operate a plurality of NIC modules at the same time according to the performance and requirements of the base station 200.

The cellular communication interface card 222 according to the second frequency band transmits and receives a radio signal to at least one of the terminal 100, the external device, and the server using the mobile communication network, And provides a cellular communication service by two frequency bands. According to an embodiment of the present invention, the cellular communication interface card 222 by the second frequency band may include at least one NIC module using the LTE-Unlicensed frequency band. For example, the LTE-Unlicensed frequency band may be a band of 2.4 GHz or 5 GHz. According to an embodiment of the present invention, the at least one NIC module can perform cellular communication with at least one of the terminal 100, the external device, and the server independently according to the cellular communication standard or protocol of the frequency band supported by the corresponding NIC module. Can be performed. The cellular communication interface card 222 may operate only one NIC module at a time or may operate a plurality of NIC modules at the same time according to the performance and requirements of the base station 200. [

The wireless LAN interface card 223 according to the second frequency band transmits and receives a wireless signal to at least one of the terminal 100, the external device, and the server through the wireless LAN connection, 2 frequency band. According to an embodiment of the present invention, the wireless LAN interface card 223 according to the second frequency band may include at least one NIC module using the wireless LAN frequency band. For example, the WLAN frequency band may be an unlicensed radio band such as a band of 2.4 GHz or 5 GHz. According to an embodiment of the present invention, at least one NIC module independently communicates with at least one of the terminal 100, the external device, and the server in accordance with a wireless LAN standard or protocol of a frequency band supported by the corresponding NIC module Can be performed. The wireless LAN interface card 223 can operate only one NIC module at a time or operate a plurality of NIC modules at the same time according to the performance and requirements of the base station 200. [

According to an embodiment of the present invention, the processor 210 transmits information on whether or not the wireless LAN communication service of the second frequency band is available through the cellular communication channel of the first frequency band with the terminal 100, Information on the period of time. Here, the information on the predetermined period is information set for transmitting the downlink data to the terminal 100 through the cellular communication channel of the second frequency band.

In addition, according to an embodiment of the present invention, the processor 210 may be a peripheral terminal capable of communicating with the base station 200 through the terminal 100 and the wireless LAN communication service of the second frequency band, And transmits the base station coexistence message including information on a predetermined period according to a standard or protocol defined in the wireless LAN communication service to the terminal 100 for a predetermined period on the cellular communication channel of the second frequency band, .

In addition, according to an embodiment of the present invention, since the terminal 100 supports the wireless LAN communication service, the processor 210 transmits the base station coexistence message Lt; RTI ID = 0.0 > coexistence < / RTI > Here, the terminal coexistence message includes information on a predetermined period.

The terminal 100 and the base station 200 shown in FIG. 12 are block diagrams according to an embodiment of the present invention. Blocks that are separately displayed are logically distinguished from elements of a device. Thus, the elements of the device described above can be mounted as one chip or as a plurality of chips depending on the design of the device. In addition, in the embodiment of the present invention, some components of the terminal 100, such as the user interface 140 and the display unit 150, may be optionally provided in the terminal 100. In addition, in the embodiment of the present invention, the user interface 140, the display unit 150, and the like may be additionally provided to the base station 200 as needed.

Referring to FIG. 13, the 3GPP NR (new radio) supports a CBG (code block group) based transmission in addition to the TB based transmission.

The TB-based transmission scheme is as follows. The UE may transmit a 1-bit HARQ-ACK per TB in order to transmit the success or failure of each TB to the BS. In order to generate an HARQ-ACK corresponding to one TB, the UE can confirm whether or not the TB is erroneous through the TB-CRC. If the TB-CRC is successfully checked, the corresponding TB can be determined as ACK, otherwise it can be determined as NACK. The base station must retransmit the TB, which is a NACK, of the HARQ-ACKs received from the UE.

The CBG-based transmission scheme is as follows. The UE can transmit a 1-bit HARQ-ACK per CBG in order to transmit the success of each CBG to the BS. In order to generate HARQ-ACK corresponding to one CBG, the UE decodes all the CBs included in the CBG and confirms the error through the CB-CRC. When all the CBs constituting one CBG have no error (when the CB-CRC is successfully checked), it can be determined as ACK. If one of the CBs constituting one CBG has an error, it is determined as NACK . The base station must retransmit the CBs included in the CBG, which is the NACK of the HARQ-ACK received from the UE. When retransmitting, it can be transmitted in the same manner as existing CBG configuration. For reference, the length of the HARQ-ACK bit transmitted from the UE to the BS may be the maximum number of CBGs configured by the BS or the number of CBGs included in the PDSCH. In addition, a 1-bit TB-based HARQ-ACK can be additionally transmitted in addition to the CBG-based HARQ-ACK. The TB-based HARQ-ACK can indicate whether the TB-CRC has been successfully checked.

14, information that may be included in the downlink control information (e.g., DCI) of a UE configured by CBG transmission includes a new data indicator (NDI), a CBGIF (CBGIF) information field, a buffer flushing indication (BFI), a TB / CBG flag, a modulation and coding scheme (MCS), and a redundancy version (RV). For reference, the fields may or may not be included in the downlink control information. It may also be included explicitly or implicitly or implicitly. The NDI indicates whether a new TB has been transmitted by 1 bit. If the new TB is transmitted, it is toggled. Otherwise, the NDI has the same value as the previous value. CBGIF may be composed of N _CBG bits (s) indicating which CBG is currently being transmitted. The BFI informs whether the currently scheduled CBGs can be soft-combined with previously transmitted CBGs. If the BFI is composed of 1 bit, if the BFI is 1 (or toggled), the corresponding CBGs should flush the buffer without performing soft combining with the previous information and decode it. If the BFI is 0 (or is not toggled), the corresponding CBGs should be soft-combined with the previous information and decoded. The BFI may be explicitly present in the downlink control information or implicitly transmitted. For example, if the UE receives a PDCCH scheduling retransmission of one TB before the HARQ-ACK transmission of the TB, the UE can perform buffer flushing. The TB / CBG flag is 1 bit indicating whether the current transmission is a CBG-based transmission or a TB-based transmission. In the NR system, if the MCS is set to maintain the bit size as it is in the LTE scheme, the modulation order and TB size can be informed by N _MCS bits. In 3GPP LTE, N _MCS is 5 bits. RV is 2bits, which can indicate the redundancy version when soft combining. However, in the NR system, the number of MCS bits and RV bits may be different from the MCS and RV used in LTE. In the following description of the present invention, 5bits for MCS and 2bits for RV are used.

In a preferred embodiment of the present invention, the base station informs the UE of a new data indication (NDI) using a field for CBG indication included in downlink control information (for example, DCI) If the CBGIF (CBG information field) is 1 in the DL control information received from the base station, the NDI is assumed to be 1 as an implicit NDI, and if CBGIF is all 0, the NDI is 0 as an implicit NDI Can be assumed. In contrast, when the BS sets 0 or 1 as a field for CBG indication in the downlink control information to be transmitted, that is, CBGIF and transmits the 1 bit NDI as an explicit NDI to the MCS field Can be reused and transmitted explicitly. If the CBGIF field has both 0s and 1s in the downlink control information received from the base station, the UE receives and analyzes the explicitly transmitted 1-bit NDI from the MCS field, It is possible to recognize the retransmission of the packet. That is, when the CBGIF is set to 1 or all of 0 in the downlink control information to be transmitted, the base station transmits the 5-bit MCS field transmitted to the UE so as to be interpreted as the modulation order and the TB size. In this case, if the CBGIF is all 1 or all 0 in the received downlink control information, the terminal interprets the 5-bit MCS field as a modulation order and a TB size. In case of setting the field for CBG indication in the downlink control information to be transmitted, that is, CBGIF having 0 and 1 together, 2bits of the 5-bit MCS field can be used to inform the modulation order, 1 bit among 3 bits can be configured as an NDI value and transmitted to the terminal. In this case, if a field for CBG indication, i.e., CBGIF, has 0s and 1s in the downlink control information received from the base station, 2bits of the 5-bit MCS field is used for reception and analysis of a modulation order, One bit of the remaining 3 bits is interpreted as being used for setting the NDI value from the base station. Through this scheme, 1bit NDI recycles only the MCS field, so DCI can reduce 1bit.

In a preferred embodiment of the present invention, when a base station implicitly transmits a 1-bit NDI through a CBGIF included in downlink control information (for example, DCI) The RV value can be used to indicate TB / CBG flags that implicitly indicate TB-based transmission or CBG-based transmission. One of the values of the RV field (e.g., 00) indicates a CBG-based transmission if the CBGIF included in the downlink control information is all 1 or all 0, and the other one (e.g., 11) Indicates a TB-based transmission. At this time, the UE can always assume that the redundancy version is 00 irrespective of the value of the RV field included in the received downlink control information. For reference, the redundancy version 00 may be a value indicating transmission of a systematic bit. If the CBGIF included in the downlink control information includes 0 and 1, the RV field included in the downlink control information may have a value of 00, 01, 10, 11, and the terminal may transmit the redundancy version Can be used as interpreted. If the CBGIF included in the DL control information includes 0 and 1, the TB / CBG flag indicating whether the TB-based transmission or the CBG-based transmission is transmitted can be explicitly transmitted through 1 bit of the MCS field. The UE receives the packet and determines whether it is a TB-based transmission or a CBG-based transmission. Here, if the CBGIF included in the downlink control information includes 0 and 1, 2 bits of the 5-bit MCS field may be used to indicate the modulation order, and one of the remaining 3 bits may be used as the TB / CBG flag.

In a preferred embodiment of the present invention, when a base station implicitly transmits a 1-bit NDI through a CBGIF included in downlink control information (for example, DCI) The RV value can be reported through the MCS field. When the value of the RV field is not a value corresponding to the TB / CBG flag, if the 1 bit value of the MCS field is 0, the UE sets the value of the RV field If the 1-bit value of the MCS field is 1, the RV value is 11 regardless of the value of the RV field. For example, if the value of the RV field is 00, CBG-based transmission is indicated. If the value of the RV field is 11, TB-based transmission is instructed. The value of 00 or 11 may be replaced by another value. If the value of the RV field is 10 or 01 and the 1 bit of the MCS is 0, the UE interprets the value of the RV field as a redundancy version and interprets it as 10 or 01, which is the value of the received RV field. Alternatively, if the 1 bit of the MCS included in the received downlink control information is set to 1, the terminal interprets the RV value as 11 even if the value of the RV field is set to 10 or 01.

When a base station implicitly transmits a 1-bit NDI through a CBGIF included in downlink control information (for example, DCI) to a terminal, a preferred embodiment of the present invention will be described with reference to FIG. 18, If the CBGIF included in the information is all 1 or all 0, there is no buffer flushing information (BFI), and soft-buffer combining is always possible. If the CBGIF included in the received downlink control information includes 1 and 0, 2 bits of the 5-bit MCS field indicates a modulation order and 1 bit of the remaining 3 bits can be used as a BFI. For reference, if the CBGIF included in the received downlink control information is all 1 or all 0s, the terminal interprets the 5-bit MCS field as a modulation order and a TB size.

When a base station implicitly transmits a 1-bit NDI through a CBGIF included in downlink control information (for example, DCI), a preferred embodiment of the present invention will be described with reference to FIG. 19, CBG-based communication if the CBGIF included in the information is all 1 or 0 and the value of the RV field is a specific value (for example, 00), 5 bits MCS indicates the modulation order and TB size, and the redundancy version value is 00 have. If the CBGIF included in the received downlink control information is all 1 or 0 and the value of the RV field is another specific value (for example, 11), the UE is a TB-based communication, and the 5bits MCS is a modulation order and a TB size , And the redundancy version value may be 00. If the CBGIF included in the received downlink control information is all 1 or 0 and the value of the RV field is not the specific values (for example, 00 and 11), the UE informs the modulation order of 2 bits of the 5 bits MCS, 1bit indicates the NDI value and the remaining 1bit indicates the CBG / TB flag. If the remaining 1bit is 0, the redundancy version value is the value of the RV field. If the remaining 1bit is 0, the redundancy version can be interpreted as 11. If the CBGIF included in the received downlink control information includes 1s and 0s, the terminal informs the modulation order of 2bits of the 5bits MCS, the redundancy version value is the value of the RV field, the remaining 1bit informs the NDI value, CBG / TB flag, and the remaining 1bit can be interpreted as BFI. For reference, the number of bits required in DCI is 7 + N _CBG . Where N _CBG is the number of bits contained in the CBGIF field.

The BFI and TB / CBG flags can be represented by 1 bit when the base station is configured to transmit downlink control information (e.g., DCI) to the UE. If the NDI included in the received downlink control information is toggled, the UE can interpret the 1 bit as a TB / CBG flag. That is, the UE can determine whether it is a TB transmission or a CBG transmission based on the BFI included in the received downlink control information and the 1 bit used for the TB / CBG flag. If the NDI included in the received downlink control information is not toggled, the terminal can interpret the 1 bit as a BFI. That is, the UE can know whether the CBG transmitted through the 1-bit BFI can be soft-combined with the previously transmitted CBG.

In a preferred embodiment of the present invention, when the base station does not transmit the 1-bit NDI through the CBGIF included in the downlink control information (for example, DCI) The N _CBG + 2 bits of the downlink control information can be interpreted differently by using the values of the RV field and the BFI field included in the downlink control information. If the value of the RV field is not 00 and the BFI value is 1, the buffer flushing is not performed, the redundancy version value is 0, and N _CBG + 2 bits DCI can be interpreted as 5 bits MCS and useless N _CBG -3 bits have. If the value of the RV field is 00 and the BFI value is 1, buffer flushing is performed, the redundancy version value is 0, and N _CBG + 2 bits DCI can be interpreted as 2 bits MCS and N _CBG bits CBGIF. If the BFI value is 0, the buffer flushing is not performed, the redundancy version value uses the value of the RV field, and N _CBG + 2 bits DCI can be interpreted as 2 bits MCS and N _CBG bits CBGIF. For reference, when the base station transmits a new TB, the value of the RV field is not 00 and the value of the BFI field is 1. For reference, the number of bits required in DCI is 6 + N _CBG .

RV (2 bits) BFI (1bit) Operation [00], [01], [10], [11] 0 No buffer flushing
Redundancy version is 0,1,2,3 from RV field
DCI interpretation: [CBGIF (N _CBG bits) MCS (2 bits)] [00] One Buffer flushing
Redundancy version is 0
DCI interpretation: [CBGIF (N _CBG bits) MCS (2 bits)] [11] or [01] or [10] One No buffer flushing
Redundancy version is 0
DCI interpretation: [MCS (5 bits) DummyBits (N _CBG -3 bits)

Referring to Table 4, N _CBG + 2 bits of DCI can be interpreted differently by using the values of the RV field and the BFI field. If the value of the RV field is a specific value (for example, 11) and the BFI value is 1, the CBG-based communication and buffer flushing are not performed, the redundancy version value is 0 and the N _CBG + 2 bits DCI is 5 bits MCS and useless N _CBG -3 bits. If the value of the RV field is a specific value other than 00 (for example, 01) and the BFI value is 1, TB-based communication and buffer flushing are not performed, the redundancy version value is 0, N _CBG + 2 bits DCI Can be interpreted as 5 bits MCS and useless N _CBG -3 bits.

RV (2 bits) BFI (1bit) Operation [11] One CBG based transmission
No buffer flushing
Redundancy version is 0
DCI interpretation: [MCS (5 bits) DummyBits (N _CBG -3 bits) [01] One TB based transmission
No buffer flushing
Redundancy version is 0
DCI interpretation: [MCS (5 bits) DummyBits (N _CBG -3 bits)

In one embodiment of the present invention, when a base station uses a subsequent transmission to retransmit some CBGs of previous CBGs before receiving HARQ-ACK feedback of the UE, downlink control information (for example, DCI) is all 1, the UE can be configured to determine that the NDI is 1, and if the CBGIF is all 0, the NDI can be set to be 0. Also, if CBGIF contains both 0 and 1, the specific RV value may represent NDI 0, and the other specific RV value may represent NDI 1. At this time, if the BFI exists explicitly in the downlink control information, it can be set to BFI = 1 (or toggling).

The terms used in the above description are used for the description of the present invention and may be named by replacing other terms. For example, the CBGIF (CBG information field) may also be referred to as CBGTI (CBG transmission information), and the BFI may be referred to as CBGFI (CBG flushing information). In order to obscure the ambiguity of the use of the term of the present invention, the description of the present invention can be described as follows, reflecting the term.

In a preferred embodiment of the present invention, information that can be included in downlink control information (e.g., DCI, Downlink Control Information) of a UE configured as a CBG transmission includes a new data indicator (NDI), a CBGTI Transmission Information, CBG Flushing Information, TB / CBG flag, Modulation and Coding Scheme (MCS), and Redundancy version (RV). For reference, the fields may or may not be included in the downlink control information. For example, the UL grant for indicating uplink transmission may not have CBGFI. It may also be included explicitly or implicitly or implicitly. The NDI indicates whether a new TB has been transmitted by 1 bit. If a new TB is transmitted, the NDI is toggled to a different value from the previous TB. Otherwise, the NDI has the same value as the previous value if retransmission of the previously transmitted TB is performed. CBGTI can be configured with N _CBG bits (s) to indicate which CBG is currently being transmitted. Here, N _CBG may be equal to the maximum number of _CBGs that the BS has configured for the UE, and each CBG is indicated according to the bits of each CBGTI. CBGFI indicates whether the currently scheduled CBGs can be soft-combined with previously transmitted CBGs. CBGFI is 1 bit, and according to the CBGFI value, the transmission CBGs indicated in CBGTI can determine whether to soft combine with previous information. The CBGFI may be explicitly present in the downlink control information or transmitted implicitly or implicitly. The TB / CBG flag is 1 bit indicating whether the current transmission is a CBG-based transmission or a TB-based transmission. In the NR system, if the MCS is set to maintain the bit size as it is in the LTE scheme, the modulation order and TB size can be informed by N _MCS bits. In 3GPP LTE, N _MCS is 5 bits. RV is 2bits, which can indicate the redundancy version when soft combining. However, in the NR system, the number of MCS bits and RV bits may be different from the MCS and RV used in LTE. In the following description of the present invention, 5bits for MCS and 2bits for RV are used.

When an NDI, a CBGTI, a CBGFI, a TB / CBG flag, an MCS, and an RV, which are information that can be included in downlink control information (e.g., DCI, Downlink Control Information) Thereby reducing the payload size of the downlink control information. In order to accomplish the above object, the present invention divides the case where the NDI value is transmitted implicitly or implicitly, and the case where the NDI value is explicitly transmitted.

The NDI value is transmitted implicitly or implicitly as follows.

15, when a field for CBG indication, i.e., CBGTI, is 0 (or 1) as a method for a base station to indicate an NDI value or a method for a terminal to obtain an NDI value, an NDI value Is 0 (or 1) and the field for CBG indication, CBGTI, contains both 0 and 1, one bit of the DCI field can be reused to convey the NDI value. Some fields may be MCS fields or RV fields. More specifically, the BS informs the UE of a new data indication (NDI) using a field for CBG indication included in the downlink control information (e.g., DCI) It is assumed that the NDI value is 1 as an implicit NDI if the CBG indication field and the CBGTI (CBG Transmission Information) field are all 1 in the information, and if the CBGTI is all 0, the NDI value is assumed to be 0 as an implicit NDI. Alternatively, in order to perform the setting of the NDI value when the CBGTI field has 0 and 1 together in the downlink control information to be transmitted, the base station sets the 1-bit NDI value as an explicit NDI to 1 bit Can be reused and transmitted explicitly. If the CBGTI field contains 0 and 1 in the downlink control information received from the base station, the UE receives and reinterprets the explicit 1 bit NDI value from 1 bit of the MCS field, It is possible to recognize whether the received data is retransmitted or not. That is, when the CBGTI is set to '1' or '0' in the downlink control information to be transmitted, the base station transmits the 5-bit MCS field transmitted to the UE so as to be interpreted as the modulation order and the TB size. In this case, if the CBGTI is all 1 or all 0 in the received downlink control information, the terminal interprets the 5-bit MCS field as a modulation order and a TB size. In contrast, when the BS sets fields for CBG indication in the downlink control information to be transmitted, that is, CBGTI is 0 and 1, 2 bits of the 5-bit MCS field can be used to inform the modulation order, 1 bit among 3 bits can be transmitted to the terminal by mapping the NDI value. In this case, if a field for CBG indication, that is, CBGTI, has 0s and 1s in the downlink control information received from the base station, 2bits of the 5-bit MCS field is used for reception and re-analysis of the modulation order , And 1 bit out of the remaining 3 bits is interpreted as being used for setting the NDI value from the base station. Through this scheme, 1bit NDI recycles only the MCS field, so DCI can reduce 1bit.

In a preferred embodiment of the present invention, when a base station implicitly transmits a 1-bit NDI through a CBGTI included in downlink control information (for example, DCI) The RV value can be used to determine whether the transmission is TB-based or CBG-based. That is, the TB / CBG flag can be implicitly / implicitly indicated. More specifically, if the CBGTI included in the downlink control information is all 1 or all 0, one of the values of the RV field (e.g., 00) indicates a CBG-based transmission and the other of the values of the RV field 11) directs TB-based transmission. At this time, the UE can always assume that the redundancy version is 00 irrespective of the value of the RV field included in the received downlink control information. For reference, the redundancy version 00 may be a value indicating transmission of a systematic bit. If the CBGTI included in the downlink control information includes both 0 and 1, the RV field included in the downlink control information may have a value of 00, 01, 10, 11, It can be interpreted as version. If the CBGTI included in the downlink control information includes 0 and 1, the TB / CBG flag indicating whether the TB-based transmission or the CBG-based transmission can be explicitly transmitted through 1 bit of the MCS field. The UE receives the packet and determines whether it is a TB-based transmission or a CBG-based transmission. Here, if the CBGTI included in the downlink control information includes both 0s and 1s, 2bits of the 5-bit MCS field may be used to indicate the modulation order, and one of the remaining 3bits may be used as the TB / CBG flag.

In a preferred embodiment of the present invention, when a base station implicitly transmits a 1 bit NDI through a CBGTI included in downlink control information (for example, DCI) 1 bit of the MCS field can be used to provide information for interpreting the RV value. More specifically, if the CBGTI included in the received downlink control information is all 0 or 1 and the value of the RV field is a value corresponding to the TB / CBG flag (e.g., 00 for CBG transmission, If the 1 bit value of the MCS field is 0, the UE can interpret the RV field value as a redundancy version. If the 1 bit value of the MCS field is 1, the RV value is the value of the RV field Regardless of whether it is 11 or not. For example, if the value of the RV field is 00, CBG-based transmission is indicated. If the value of the RV field is 11, TB-based transmission is instructed. The value of 00 or 11 may be replaced by another value. If the value of the RV field is 10 or 01 and the 1 bit of the MCS is 0, the UE interprets the value of the RV field as a redundancy version and interprets it as 10 or 01, which is the value of the received RV field. Alternatively, if the 1 bit of the MCS included in the received downlink control information is set to 1, the terminal interprets the RV value as 11 even if the value of the RV field is set to 10 or 01.

When a base station implicitly transmits a 1-bit NDI through a CBGTI included in downlink control information (for example, DCI), a preferred embodiment of the present invention uses 1 bit of the MCS field CBGFI < / RTI > More specifically, if the CBGTI included in the received downlink control information is all 1 or all 0, the UE can always assume soft-buffer combining, and if the CBGTI included in the received downlink control information is 1 and 0 , 2 bits of the 5-bit MCS field indicates the modulation order, and 1 bit of the remaining 3 bits can be used to explicitly indicate the CBGFI value. For reference, if the CBGTI included in the received downlink control information is all 1 or all 0s, the UE interprets the 5-bit MCS field as a modulation order and a TB size.

Referring to FIG. 19, when a base station implicitly transmits a 1-bit NDI through a CBGTI included in downlink control information (e.g., DCI), a base station transmits an MCS , CBGFI, and TB / CBG flag values can be transmitted using the MCS field. More specifically, if the CBGTI included in the received downlink control information is all 1s or 0s and the value of the RV field is a specific value (for example, 00), the UE is a CBG-based communication, and the 5bits MCS is a modulation order and a TB size, and the redundancy version value may be 00. If the CBGTI included in the received downlink control information is all 1 or 0, and the value of the RV field is another specific value (for example, 11), the UE sets the modulation order and the TB size , And the redundancy version value may be 00. If the CBGTI included in the received downlink control information is all 1 or 0 and the value of the RV field is not the specific values (for example, 00 and 11), the terminal informs the modulation order of 2 bits of the 5 bits MCS, 1bit indicates the NDI value and the remaining 1bit indicates the CBG / TB flag. If the remaining 1bit is 0, the redundancy version value is the value of the RV field. If the remaining 1bit is 0, the redundancy version can be interpreted as 11. If the CBGTI included in the received downlink control information includes 1 and 0, the redundancy version value is the value of the RV field, 2 bits of the 5 bits MCS inform the modulation order, the remaining 1 bit indicates the NDI value, Can indicate the CBG / TB flag, and the remaining 1 bit can be interpreted as CBGFI. Where N _CBG is the number of bits in the CBGTI field.

When a base station transmits downlink control information (for example, DCI) to the UE, CBGFI and TB / CBG flags can be represented by 1 bit. If the NDI value included in the received downlink control information is toggled, the UE can interpret the 1 bit as a TB / CBG flag. That is, the UE can determine whether it is a TB transmission or a CBG transmission through 1 bit used for CBGFI and TB / CBG flags included in the received downlink control information. If the NDI value included in the received downlink control information is not toggled, the UE can interpret the 1 bit as a CBGFI value. That is, the UE can know whether the currently transmitted CBG can be soft-combined with the previously transmitted CBG through the corresponding CBGFI value.

In an embodiment of the present invention, when using a subsequent transmission that retransmits some of the CBGs of the same TB as the TB corresponding to the HARQ-ACK feedback before transmitting the HARQ-ACK feedback, The NDI value is known by the value. More specifically, if the CBGTI of the downlink control information (e.g., DCI) for subsequent transmission is all 1, the UE can set the NDI value to be 1, and if the CBGTI is all 0, the NDI value is determined to be 0 . Also, if CBGTI contains both 0s and 1s, the specific RV field value indicates an NDI value of 0, and the other specific RV field value may indicate an NDI value of 1. [ The redundancy version value may always be 0 (ie, including systematic bits) regardless of the value of the RV field. At this time, if CBGFI exists explicitly in the downlink control information, CBGFI = 1 (or toggling) can be set.

When the NDI value is explicitly transmitted, it is as follows.

In the present invention, when a UE capable of receiving or transmitting a CBG-based transmission is first described on a downlink basis, a Node B sends an NDI to the UE, an explicit NDI field (e.g., A joint coding method for DCI information which can include all or part of MCS and NDI, CBGTI, CBGFI, and RV explicitly or implicitly, and the method of DCI configuration of the base station according to each joint coding method, To a method for receiving a DCI and interpreting the DCI. In case of uplink, in case that the base station transmits DCI information which can explicitly or implicitly include MCS, NDI, CBGTI, CBGFI and RV in all or part of the MCS to the UE, the UE receives the corresponding DCI information, The present invention can be applied equally to a method for interpreting the data.

When the BS transmits downlink control information through the downlink control channel, the Node B always includes an NDI (New Data Indicator) as an explicit NDI field in the downlink control information (e.g., DCI) In the preferred embodiment of the present invention, when the CBGTI is all 1 or 0, the NDI field may be mapped to a 1-bit NDI value, When the CBGTI contains both 1s and 0s, the NDI field can be transmitted with a 1-bit CBGFI value mapped.

When the BS transmits downlink control information through the downlink control channel, the Node B always includes an NDI (New Data Indicator) as an explicit NDI field in the downlink control information (e.g., DCI) In the embodiment of the present invention, the 1-bit NDI value is mapped to the NDI field according to the value of the MCS field, and the 1-bit NDI value is transmitted in the NDI field, 1bit CBGFI values can be mapped and transmitted. The UE may interpret the NDI field value as an NDI value or a CBGFI value according to the value of the MCS field. Preferably, when the value of the MCS field indicates the information of the modulation order and the transport block sizes, the value of the NDI field is interpreted as the NDI value. When the value of the MCS field only indicates the modulation order, Can be interpreted.

In order to inform the UE of the buffer flushing instruction in the above method, the CBGFI value may be instructed to flush buffer when the value is a specific value (for example, '1' or toggling value of the previous value) regardless of the NDI value. Alternatively, the CBGFI value for informing the UE of the buffer flushing indication may be determined according to the NDI value of the corresponding TB. For example, if the value of NDI is different from the value of CBGFI, buffer flushing is performed. Otherwise, if the value of NDI is equal to the value of CBGFI, buffer flushing may be performed. For example, when the NDI value of the TB is 0, if the CBGFI value is 0, buffer flushing is not performed, and when the CBGFI value is 1, buffer flushing can be performed. Conversely, when the NDI value of the TB is 1, if the CBGFI value is 0, buffer flushing is performed, and when the CBGFI value is 1, buffer flushing may not be performed.

When the BS transmits downlink control information through the downlink control channel, the Node B always includes an NDI (New Data Indicator) as an explicit NDI field in the downlink control information (e.g., DCI) The present invention is not limited to this, but the present invention is not limited thereto. Referring to Table 5, the UE calculates the value of the RV field included in the received downlink control information So that the downlink control information can be interpreted differently. Preferably, the downlink control information that can be interpreted differently may include a CBGTI field and an MCS field. In one embodiment, assume that only Y bits out of X bits in the MCS field are used for retransmission, and CBGTI is N _CBG bits. If N _CBG is greater than or equal to XY, the N _CBG + Y bits of DCI may represent CBGTI information and MCS information. If the value of the RV field is 00, the redundancy version value is used as 0, the N _CBG + Y bits of the DCI can include the X bits MCS, and the N _CBG - (XY) bits can be reused for other purposes The bit field can be interpreted as an interpretable bit field. If the value of the RV field is not 00, the redundancy version value corresponds to the RV field, and the N _CBG + Y bits information included in the DCI can be interpreted as a CBGTI having Y bits MCS and N _CBG bits used for retransmission have. At this time, the Y bit MCS can inform the modulation order. When N _CBG is less than XY, the X bits of the DCI may represent CBGTI information and MCS information. If the value of the RV field is 00, the X bits of the DCI indicate the MCS information. If the value of the RV field is not 00, the Y bits of the X bits of the DCI indicate the MCS information, the N _CBG bits indicate the CBGTI information, - (Y + N _CBG ) bits can be set to be interpreted as bit fields that can be reused for other purposes. In this embodiment, X and Y used in the MCS field may be X = 5 and Y = 2 with reference to the LTE system.

RV (2 bits) Operation [00] Redundancy version is 0
DCI interpretation:
[MCS (X bits) DummyBits (N _CBG - (XY) bits)] if N _CBG? XY
or [MCS (X bits)], otherwise [01] or [10] or [11] Redundancy version is 1 or 2 or 3
DCI interpretation:
[MCS (Y bits) CBGTI (N _CBG bits)] if if N _CBG? XY,
or [MCS (Y bits) CBGTI (N _CBG bits) Dummy bits (XYN _CBG bits)], otherwise

When the BS transmits downlink control information through the downlink control channel, the Node B always includes an NDI (New Data Indicator) as an explicit NDI field in the downlink control information (e.g., DCI) The present invention is not limited to this, but the present invention is not limited thereto. Referring to Table 6, the UE calculates the value of the RV field included in the received downlink control information So that the downlink control information can be interpreted differently. Preferably, the downlink control information that can be interpreted differently may include an NDI field, a CBGTI field, and an MCS field. In one embodiment, assume that only Y bits out of X bits in the MCS field are used for retransmission, and CBGTI is N _CBG bits. When N _CBG is 1 + XY or more, NCBG + Y bits of DCI can indicate CBGTI information, MCS information, NDI information. If the value of the RV field is 00, the redundancy version value is used as 0, and N _CBG + Y bits DCI may include X bits MCS and 1 bit NDI, and for N _CBG - (1 + X) It can be set to be interpreted as a reusable bit field for other purposes. If the value of the RV field is not 00, the redundancy version value corresponds to the RV field, and the N _CBG + Y bits information included in DCI can be interpreted as Y bits MCS and N _CBG bits CBGTI used for retransmission. For cases where N _CBG is less than 1 + XY, the 1 + X bits of DCI may represent CBGTI information, MCS information, and NDI information. If the value of the RV field is 00, the 1 + X bits of the DCI indicate the X bits MCS information and the 1 bit NDI information. If the value of the RV field is not 00, the Y bits of the 1 + X bits of the DCI indicate the MCS information, _{The CBG} bits indicate CBGTI information and can be set to be interpreted as a bit field that can be reused for other purposes for 1 + X- (Y + N _CBG ) bits. In this embodiment, X and Y used in the MCS field may be X = 5 and Y = 2 with reference to the LTE system.

RV (2 bits) Operation [00] Redundancy version is 0
DCI interpretation:
[MCS (X bits) NDI (1 bits) DummyBits (N _CBG - (1 + XY) bits)], if N _CBG ? 1+
or [MCS (X bits) NDI (1 bits)], otherwise [01] or [10] or [11] Redundancy version is 1 or 2 or 3
DCI interpretation:
[MCS (Y bits) CBGTI (N _CBG bits)], if N _CBG > = 1 + XY,
or [MCS (Y bits) CBGTI (N _CBG bits) DummyBits (X-Y + 1-N _CBG )], otherwise

When the BS transmits downlink control information through the downlink control channel, the Node B always includes an NDI (New Data Indicator) as an explicit NDI field in the downlink control information (e.g., DCI) The present invention is not limited to this. However, the present invention is not limited to this, and the present invention is not limited to this. For example, the RV field included in the received downlink control information And the value of the CBGFI field may be used to analyze the downlink control information differently. Preferably, the downlink control information that can be interpreted differently may include a CBGTI field and an MCS field. In one embodiment, assume that only Y bits out of X bits in the MCS field are used for retransmission, and CBGTI is N _CBG bits. If N _CBG is greater than or equal to XY, the N _CBG + Y bits of DCI may represent CBGTI information and MCS information. If the RV field value is not 00 and the CBGFI field value is 1, the buffer flushing is not performed, the redundancy version value is used as 0, the N _CBG + Y bits of DCI may include X bits MCS, In addition, N _CBG - (XY) bits can be set to be interpreted as bit fields that can be reused for other purposes. If the value of the RV field is 00 and the CBGFI value is 1, buffer flushing is performed and the redundancy version value is set to 0. The N _CBG + Y bits information included in the DCI includes the Y bits MCS used for retransmission and N It can be interpreted as CBGTI with _CBG bits. If the CBGFI value is 0, the buffer flushing is not performed and the redundancy version value is used in the RV field regardless of the value of the RV field. The N _CBG + Y bits information included in the DCI is used for the Y It can be interpreted as CBGTI with bits MCS and N _CBG bits.

When N _CBG is less than XY, the X bits of the DCI may represent CBGTI information and MCS information. If the value of the RV field is not 00 and the CBGFI field value is 1, the buffer flushing is not performed, the redundancy version value is used as 0, and the X bits of DCI may include X bits MCS. If the value of the RV field is 00 and the CBGFI value is 1, buffer flushing is performed and the redundancy version value is set to 0. The X bits information included in the DCI includes Y bits MCS and N _CBG bits used for retransmission Can be interpreted as CBGTI and XYN _CBG bits can be interpreted as bit fields that can be reused for other purposes. If the CBGFI value is 0 regardless of the value of the RV field, the buffer flushing is not performed, the redundancy version value is used in the RV field, and the X bits information included in the DCI is the Y bits MCS used in the retransmission Can be interpreted as a CBGTI with N _CBG bits, and XYN _CBG bits can be interpreted as a reusable bit field for other purposes.

The above description describes one embodiment as an analysis method according to the combination of the value of the RV field and the value of the CBGFI field, and other analysis methods may be included.

RV
(2bits) CBGFI (1 bit) Operation [00], [01], [10], [11] 0 No buffer flushing
Redundancy version is 0,1,2,3 from RV field
DCI interpretation:
[MCS (Y bits) CBGTI (N _CBG bits)], if N _CBG ≥ XY,
or [MCS (Y bits) CBGTI (N _CBG bits) DummyBits (XYN _CBG )], otherwise [00] One Buffer flushing
Redundancy version is 0
DCI interpretation:
[MCS (Y bits) CBGTI (N _CBG bits)], if N _CBG ≥ XY,
or [MCS (Y bits) CBGTI (N _CBG bits) DummyBits (XYN _CBG )], otherwise [11], [01], [10] One No buffer flushing
Redundancy version is 0
DCI interpretation:
[MCS (X bits) DummyBits (N _CBG - (XY) bits)], if N _CBG ≥ XY,
or [MCS (X bits)], otherwise

When the BS transmits downlink control information through the downlink control channel, the Node B always includes an NDI (New Data Indicator) as an explicit NDI field in the downlink control information (e.g., DCI) The present invention is not limited to this, but the present invention is not limited thereto. Referring to Table 8, the UE determines the value of the RV field included in the received downlink control information, The combination of the values of the CBGFI field can be used to differentiate the downlink control information. Preferably, the downlink control information that can be interpreted differently may include a CBGTI field, an MCS field, and an NDI field. In one embodiment, assume that only Y bits out of X bits in the MCS field are used for retransmission, and CBGTI is N _CBG bits. When N _CBG is 1 + XY or more, N _CBG + Y bits of DCI can indicate CBGTI information, MCS information, NDI information. If the RV field value is not 00 and the CBGFI field value is 1, the buffer flushing is not performed, the redundancy version value is used as 0, and the N _CBG + Y bits of the DCI include the X bits MCS and 1 bit NDI And for N _CBG - (1 + XY) bits, it can be interpreted as a bit field that can be reused for other purposes. If the value of the RV field is 00 and the CBGFI value is 1, buffer flushing is performed and the redundancy version value is set to 0. The N _CBG + Y bits information included in the DCI includes the Y bits MCS used for retransmission and N It can be interpreted as CBGTI with _CBG bits. If the CBGFI value is 0, the buffer flushing is not performed and the redundancy version value is used in the RV field regardless of the value of the RV field. The N _CBG + Y bits information included in the DCI is used for the Y It can be interpreted as CBGTI with bits MCS and N _CBG bits.

For cases where N _CBG is less than 1 + XY, the X bits of the DCI may represent CBGTI information, MCS information, and NDI information. If the value of the RV field is not 00 and the CBGFI field value is 1, the buffer flushing is not performed, the redundancy version value is used as 0, and the X bits of DCI can include X bits MCS and 1 bit NDI . If the value of the RV field is 00 and the CBGFI value is 1, buffer flushing is performed and the redundancy version value is set to 0. The 1 + X bits information included in the DCI includes Y bits MCS and N _CBG bits can be interpreted as a CBGTI and 1 + XYN _CBG bits can be interpreted as bit fields that can be reused for other purposes. If the CBGFI value is 0, the buffer flushing is not performed and the redundancy version value is used in the RV field regardless of the value of the RV field. The 1 + X bits information included in the DCI is the Y bits Can be interpreted as CBGTI with MCS and N _CBG bits, and 1 + XYN _CBG bits can be interpreted as bit fields that can be reused for other purposes.

The above description describes one embodiment as an analysis method according to the combination of the value of the RV field and the value of the CBGFI field, and other analysis methods may be included.

RV (2 bits) CBGFI (1 bit) Operation [00], [01], [10], [11] 0 No buffer flushing
Redundancy version is 0,1,2,3 from RV field
DCI interpretation:
[MCS (Y bits) CBGTI (N _CBG bits)], if N _CBG > = 1 + XY,
or [MCS (Y bits) CBGTI (N _CBG bits) DummyBits (X-Y + 1-N _CBG )], otherwise [00] One Buffer flushing
Redundancy version is 0
DCI interpretation:
[MCS (Y bits) CBGTI (N _CBG bits)], if N _CBG > = 1 + XY,
or [MCS (Y bits) CBGTI (N _CBG bits) DummyBits (X-Y + 1-N _CBG )], otherwise [11], [01], [10] One No buffer flushing
Redundancy version is 0
DCI interpretation:
[MCS (X bits) NDI (1 bits) DummyBits (N _CBG - (1 + XY) bits)], if N _CBG ? 1+
or [MCS (X bits) NDI (1 bits)], otherwise

The present invention can be further considered as a method of distinguishing CBG-based transmission from TB-based transmission using a combination of an RV field value and a CBGFI field value included in the DCI. This method will be described as an embodiment of Tables 9 and 10.

As an embodiment of the present invention, referring to Tables 7 and 9, a combination of the RV field value and the CBGFI field value can be used to determine whether the transmission is CBG-based transmission or TB-based transmission. That is, the CBG / TB flag can be implicitly transmitted. In the case where the value of the RV field in Table 7 is not 00 and the value of the CBGFI field is 1, it is possible to judge whether the CBG-based transmission or the TB-based transmission is performed using a combination of the RV field value and the CBGFI field value. Referring to Table 9, if the value of the RV field is 11, it is CBG-based transmission, and if it is 01, TB-based transmission can be determined.

RV (2 bits) CBGFI (1 bit) Operation [11] One CBG based transmission
No buffer flushing
Redundancy version is 0
DCI interpretation:
[MCS (X bits) DummyBits (N _CBG - (XY) bits)], if N _CBG ≥ XY,
or [MCS (X bits)], otherwise [01] One TB based transmission
No buffer flushing
Redundancy version is 0
DCI interpretation:
[MCS (X bits) DummyBits (N _CBG - (XY) bits)], if N _CBG ≥ XY,
or [MCS (X bits)], otherwise

Referring to Tables 8 and 10, as an embodiment of the present invention, a combination of the RV field value and the CBGFI field value can be used to determine whether the CBG-based transmission is a TB-based transmission. That is, the CBG / TB flag can be implicitly transmitted. If the value of the RV field in Table 8 is not 00 and the value of the CBGFI field is 1, a combination of the RV field value and the CBGFI field value can be used to determine whether the CBG-based transmission is TB-based transmission. Referring to Table 10, if the value of the RV field is 11, it is CBG-based transmission, and if it is 01, TB-based transmission can be determined.

RV (2 bits) CBGFI (1 bit) Operation [11] One CBG based transmission
No buffer flushing
Redundancy version is 0
DCI interpretation:
[MCS (X bits) NDI (1 bits) DummyBits (N _CBG - (1 + XY) bits)], if N _CBG ? 1+
or [MCS (X bits) NDI (1 bits)], otherwise [01] One TB based transmission
No buffer flushing
Redundancy version is 0
DCI interpretation:
[MCS (X bits) NDI (1 bits) DummyBits (N _CBG - (1 + XY) bits)], if N _CBG ? 1+
or [MCS (X bits) NDI (1 bits)], otherwise

In one embodiment of the present invention, the RV field of the downlink control information (e.g., DCI) may be used for CBGTI. As a preferred example, if a CBG-based transmission is indicated, the redundancy version value may be determined according to the slot index over which the DCI is transmitted. The redundancy version value may be determined according to the slot index and the UE's unique value (UE ID or C-RNTI value).

While the methods and systems of the present invention have been described in connection with specific embodiments, some or all of those elements or operations may be implemented using a computer system having a general purpose hardware architecture.

It will be understood by those skilled in the art that the foregoing description of the present invention is for illustrative purposes only and that those of ordinary skill in the art can readily understand that various changes and modifications may be made without departing from the spirit or essential characteristics of the present invention. will be. It is therefore to be understood that the above-described embodiments are illustrative in all aspects and not restrictive. For example, each component described as a single entity may be distributed and implemented, and components described as being distributed may also be implemented in a combined form.

The scope of the present invention is defined by the appended claims rather than the detailed description and all changes or modifications derived from the meaning and scope of the claims and their equivalents are to be construed as being included within the scope of the present invention do.

Claims (1)

A method, apparatus and system for transmitting downlink control information to a terminal configured to receive a code block group (CBG) -based transmission in a mobile communication system

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