RU2779154C2 - Method and device for transmission and reception of wireless signal in wireless communication system - Google Patents

Abstract

FIELD: wireless communication.

SUBSTANCE: first cell with the first transmission time interval (hereinafter – TTI) is combined with the second cell with the second TTI, wherein the length of the second TTI is N (N > 1) times more than the length of the first TTI; data planning information is received for the second cell in the first TTI of the first cell; and data transmission is established based on data planning information in the second TTI of the second cell, corresponding to the first TTI of the first cell, wherein the first TTI for the first cell is any TTI of N TTI of the first cell, corresponding to the second TTI of the second cell.

EFFECT: increase in the efficiency of transmission/reception of control information.

18 cl, 20 dwg, 3 tbl

Description

FIELD OF TECHNOLOGY TO WHICH THE INVENTION RELATES

[0001] The present invention relates to a wireless communication system and, in particular, to a method and apparatus for transmitting/receiving a wireless signal. The wireless communication system includes a CA-based (carrier aggregation) based wireless communication system.

BACKGROUND OF THE INVENTION

[0002] In general, a wireless communication system is developed to cover a wide range in various ways to provide a communication service such as an audio communication service, a data communication service, and the like. Wireless communication is a kind of multiple access system capable of communicating with multiple users. by sharing available system resources (eg bandwidth, transmit power, etc.). For example, the multiple access system may include one of a CDMA (Code Division Multiple Access) system, an FDMA (Frequency Division Multiple Access) system, a TDMA (Time Division Multiple Access) system, an OFDMA (Orthogonal Frequency Division Multiple Access) system. ), SC-FDMA (Single Carrier Frequency Division Multiple Access), etc.

SUMMARY OF THE INVENTION

TECHNICAL PROBLEM

[0003] An object of the present invention is to provide a method and apparatus for efficiently transmitting/receiving control information in wireless communications.

[0004] The technical objectives obtained from the present invention are not limited to the above technical object. Other technical problems not mentioned will be readily understood by those skilled in the art to which the present invention pertains from the following description.

TECHNICAL SOLUTION

[0005] In order to achieve these and other advantages, and in accordance with the purpose of the present invention, as embodied and described broadly, according to one embodiment, a method for communicating by a user equipment in a wireless communication includes: aggregating a first cell having a first cell length TTI (transmission time interval), with the second cell having a second TTI length, wherein the second TTI length corresponds to N (N>1) times the first TTI length, receiving data scheduling information for the second cell in the first TTI of the first cell, and performing data transmission in the second TTI of the second cell corresponding to the first TTI of the first cell, based on the data scheduling information. In this case, the first TTI of the first cell may correspond to one of the N TTIs of the first cell corresponding to the second TTI of the second cell.

[0006] To further achieve these and other advantages, and in accordance with the purpose of the present invention, according to another embodiment, a user equipment in a wireless communication system includes: an RF (radio frequency) module and a processor, the processor being capable of aggregating a first cell, having a first TTI (transmission time interval) length, with a second cell having a second TTI length, wherein the second TTI length corresponds to N (N>1) times the first TTI length, the processor is configured to receive data scheduling information for the second cell in the first TTI of the first cell, the processor is configured to transmit data at the second TTI of the second cell corresponding to the first TTI of the first cell, based on the data scheduling information. In this case, the first TTI of the first cell may correspond to one of the N TTIs of the first cell corresponding to the second TTI of the second cell.

[0007] Preferably, the N TTIs of the first cell corresponding to the second TTI of the second cell are divided into TTI groups, and the first TTI of the first cell corresponds to a TTI belonging to a specific TTI group of the TTI groups.

[0008] Preferably, the position of the TTI corresponding to the first TTI of the first cell may change over time in a particular TTI group.

[0009] Preferably, the first TTI of the first cell may correspond to a TTI overlapping with the first OFDM symbol in the time domain of the plurality of OFDM (orthogonal frequency division multiplexing) symbols constituting the second TTI of the second cell out of the N TTIs of the first cell corresponding to the second TTI of the second cell.

[0010] Preferably, the method may further include the step of sequentially tracking the N TTIs of the first cell corresponding to the second TTI of the second cell to receive data scheduling information for the second cell. In this case, if data scheduling information for the second cell is detected while there is a TTI to be tracked, tracking on the N TTIs of the first cell may end.

[0011] Preferably, the subcarrier spacing configured for the first cell may be larger than the subcarrier spacing configured for the second cell.

USEFUL RESULTS

[0012] According to the present invention, wireless signal transmission and reception can be efficiently performed in a wireless communication system.

[0013] The results obtained from the present invention may not be limited to the above result. Other results not mentioned will be readily understood by those skilled in the art to which the present invention relates from the following description.

BRIEF DESCRIPTION OF THE DRAWINGS

[0014] The accompanying drawings, which are included to provide a further understanding of the invention and are included in and form a part of this specification, illustrate embodiments of the invention and, together with the description, serve to explain the principles of the invention.

[0015] FIG. 1 shows the physical channels used in 3GPP LTE(-A) and how they are transmitted.

[0016] FIG. 2 shows the structure of a radio frame.

[0017] FIG. 3 shows a downlink slot resource grid.

[0018] FIG. 4 shows the structure of the downlink subframe.

[0019] FIG. 5 shows an example of an Enhanced Physical Downlink Control Channel (EPDCCH).

[0020] FIG. 6 shows the structure of an uplink subframe used in LTE(-A).

[0021] FIG. 7 shows a Single Carrier Frequency Division Multiple Access (SC-FDMA) scheme and an Orthogonal Frequency Division Multiple Access (OFDMA) scheme.

[0022] FIG. 8 shows UL HARQ (Hybrid Automatic Uplink Repeat Request) operation.

[0023] FIG. 9 and FIG. 10 illustrate examples of the random access procedure.

[0024] FIG. 11 shows the uplink/downlink frame timing relationship.

[0025] FIG. 12 shows a wireless communication system based on carrier aggregation (CA).

[0026] FIG. 13 shows inter-carrier scheduling.

[0027] FIG. 14 shows analog beamforming.

[0028] FIG. 15 shows the structure of a single subframe.

[0029] FIG. 16-19 illustrate signal transmission according to the present invention.

[0030] FIG. 20 shows a base station and user equipment applicable to an embodiment of the present invention.

IMPLEMENTATION OF THE INVENTION

[0031] Embodiments of the present invention are applicable to various wireless access technologies, for example, code division multiple access (CDMA), frequency division multiple access (FDMA), time division multiple access (TDMA), orthogonal frequency division multiple access ( OFDMA) and Single Carrier Frequency Division Multiple Access (SC-FDMA). CDMA may be implemented as a radio technology such as Universal Terrestrial Radio Access (UTRA) or CDMA2000. TDMA can be implemented as a radio technology such as Global System for Mobile Communications (GSM)/General Packet Radio Service (GPRS)/GSM Evolved Data Rates (border). OFDMA can be implemented as a radio technology, such as Institute of Electrical and Electronics Engineers (IEEE) 802.11 (Wireless Fidelity (Wi-Fi)), IEEE 802.16 (Worldwide interoperability for Microwave Access (WiMAX)), IEEE 802.20, and advanced UTRA (E-UTRA). UTRA is part of the Universal Mobile Telecommunications System (UMTS). The 3rd Generation Partnership Project Long Term Evolution (LTE) Project (3GPP) is part of Evolved UMTS (E-UMTS) using E-UTRA using OFDMA for the downlink and SC-FDMA for the uplink. LTE-Advanced (LTE-A) evolves from 3GPP LTE. In the following description, 3GPP LTE/LTE-A is considered for clarity, this is purely illustrative and thus should not be construed as limiting the present invention.

[0032] In a wireless communication system, a user equipment (UE) receives information on the downlink (DL) from a base station (BS) and transmits the information to the BS on the uplink (UL). The information transmitted and received by the BS and the UE includes data and various control information, and includes various physical channels according to the type/use of the information transmitted and received by the UE and the BS.

[0033] FIG. 1 shows the physical channels used in 3GPP LTE(-A) and how they are transmitted.

[0034] At power-up, or when the UE initially enters a cell, the UE performs an initial cell search involving synchronization with the BS in step S101. For the initial cell search, the UE synchronizes with the BS and obtains information such as a cell identifier (ID) by receiving a Primary Synchronization Channel (P-SCH) and a Secondary Synchronization Channel (S-SCH) from the BS. The UE may then receive broadcast information from the cell on a physical broadcast channel (PBCH). Meanwhile, the UE may check the downlink channel status by receiving a downlink reference signal (DL RS) during the initial cell search.

[0035] After the initial cell search, the UE may obtain more specific system information by receiving a physical downlink control channel (PDCCH) and receiving a physical downlink shared channel (PDSCH) based on the PDCCH information in step S102.

[0036] The UE may perform a random access procedure to access the BS in steps S103 to S106. For random access, the UE may transmit a preamble to a BS on a physical random access channel (PRACH) (S103) and receive a preamble response message on the PDCCH and the PDSCH corresponding to the PDCCH (S104). In the case of contention-based random access, the UE may perform a contention resolution procedure by additionally transmitting a PRACH (S105) and receiving the PDCCH and PDSCH corresponding to the PDCCH (S106).

[0037] After the above procedure, the UE may receive the PDCCH/PDSCH (S107) and transmit the Physical Uplink Shared Channel (PUSCH)/Physical Uplink Control Channel (PUCCH) (S108), as a general downlink signaling procedure communication/uplink. The control information transmitted from the UE to the BS is referred to as uplink control information (UCI). The UCI includes hybrid automatic repeat and request acknowledgment/negative acknowledgment (HARQ-ACK/NACK), scheduling request (SR), channel state information (CSI), and so on. The CSI includes a channel quality indicator (CQI), a precoding matrix indicator (PMI), a rank indicator (RI), and so on. When the UCI is transmitted on the PUCCH in general, the UCI may be transmitted on the PUSCH when control information and traffic data need to be transmitted at the same time. In addition, the UCI may be aperiodically transmitted on the PUSCH upon a network request/command.

[0038] FIG. 2 shows the structure of a radio frame. Uplink/downlink data packets are transmitted on a subframe basis. A subframe is defined as a predetermined time interval including multiple symbols. 3GPP LTE supports a type 1 radio frame structure applicable to frequency division duplexing (FDD) and a type 2 radio frame structure applicable to time division duplexing (TDD).

[0039] FIG. 2(a) shows the structure of a type 1 radio frame. The downlink subframe includes 10 subframes, each including 2 slots in the time domain. The time to transmit a subframe is defined as a transmission time interval (TTI). For example, each subframe has a duration of 1 ms and each slot has a duration of 0.5 ms. A slot includes multiple OFDM symbols in the time domain and includes multiple resource blocks (RBs) in the frequency domain. Because 3GPP LTE uses OFDM on the downlink, an OFDM symbol represents a symbol period. An OFDM symbol may be referred to as an SC-FDMA symbol or a symbol period. The RB as a resource allocation unit may include multiple consecutive subcarriers in one slot.

[0040] The number of OFDM symbols included in one slot may depend on the cyclic prefix (CP) configuration. CPs include extended CP and normal CP. When an OFDM symbol is configured by a normal CP, for example, the number of OFDM symbols included in one slot may be 7. When an OFDM symbol is configured by an extended CP, the length of one OFDM symbol increases, and thus the number of OFDM symbols included in one slot, less than in the case of a normal CP. In the case of extended CP, the number of OFDM symbols allocated to one slot may be 6. When the channel condition is unstable, such as when the UE is moving at high speed, extended CP may be used to reduce inter-symbol interference.

[0041] When using a normal CP, one subframe includes 14 OFDM symbols since one slot has 7 OFDM symbols. The first three OFDM symbols at most in each subframe may be allocated to the PDCCH and the remaining OFDM symbols may be allocated to the PDSCH.

[0042] FIG. 2(b) shows the structure of a type 2 radio frame. A type 2 radio frame includes 2 fields. Each half frame includes 4(5) normal subframes and 10 special subframes. Normal subframes are used for uplink or downlink according to the UL-DL configuration. A subframe consists of 2 slots.

[0043] Table 1 shows subframe configurations in a radio frame according to UL-DL configurations.

[0044] Table 1

Uplink - Downlink Configuration Downlink to Uplink Switching Period Subframe number 0 one 2 3 four 5 6 7 eight 9 0 5 ms D S U U U D S U U U one 5 ms D S U U D D S U U D 2 5 ms D S U D D D S U D D 3 10 ms D S U U U D D D D D four 10 ms D S U U D D D D D D 5 10 ms D S U D D D D D D D 6 5 ms D S U U U D S U U D

[0045] In Table 1, D denotes a downlink subframe, U denotes an uplink subframe, and S denotes a specific subframe. The specific subframe includes DwPTS (downlink pilot timeslot), GP (guard period), and UpPTS (uplink pilot timeslot). DwPTS is used for initial cell search, timing or channel estimation at the UE, and UpPTS is used for channel estimation at the BS and uplink transmission timing at the UE. The GP removes the UL interference caused by the multipath delay of the DL signal between the UL and the DL.

[0046] The structure of the radio frame is only illustrative, and the number of subframes included in the radio frame, the number of slots included in the subframe, and the number of symbols included in the slot may vary.

[0047] FIG. 3 shows a downlink slot resource grid.

[0048] Referring to FIG. 3, a downlink slot includes multiple OFDM symbols in the time domain. Although one downlink slot may include 7 OFDM symbols and one resource block (RB) may include 12 subcarriers in the frequency domain in the figure, the present invention is not limited thereto. Each element in the resource grid is referred to as a resource element (RE). One RB includes 12×7 RE. The number of NRBs of RBs included in a downlink slot depends on the downlink transmission band. The uplink slot structure may be identical to the downlink slot structure.

[0049] FIG. 4 shows the structure of the downlink subframe.

[0050] Referring to FIG. 4, a maximum of three (four) OFDM symbols located in the leading portion of the first slot in the subframe correspond to the control zone to which the control channel is allocated. The remaining OFDM symbols correspond to a data zone to which a physical downlink shared channel (PDSCH) is allocated. The basic unit of a data zone resource is the RB. Examples of downlink control channels used in LTE include Physical Control Format Indicator Channel (PCFICH), Physical Downlink Control Channel (PDCCH), Hybrid ARQ Physical Indicator Channel (PHICH), etc. The PCFICH is transmitted in the first OFDM symbol of the subframe and carries information regarding the number of OFDM symbols used to transmit control channels in the subframe. PHICH is an uplink transmission response and carries an acknowledgment (ACK)/negative acknowledgment (NACK) HARQ signal. The control information transmitted on the PDCCH is referred to as downlink control information (DCI). The DCI includes uplink or downlink scheduling information or an uplink transmit power control command for an arbitrary group of UEs.

[0051] The control information transmitted on the PDCCH is referred to as downlink control information (DCI). Formats 0, 3, 3A and 4 for uplink and formats 1, 1A, 1B, 1C, 1D, 2, 2A, 2B and 2C for downlink are defined as DCI formats. Information field type, number of information fields, number of bits of each information field, etc. Depend on the DIC format. For example, DCI formats selectively include information such as switch flag, RB assignment, MCS (modulation and coding scheme), RV (redundancy version), NDI (new data pointer), TPC (transmit power control), HARQ process number, confirmation of the PMI (precoding matrix indicator) as needed. Accordingly, the size of the control information negotiated with the DCI format depends on the DCI format. An arbitrary DCI format may be used to convey two or more types of control information. For example, DIC formats 0/1A is used to carry DCI format 0 or DIC format 1, which are distinguished from each other by a flag field.

[0052] The PDCCH may carry a downlink shared channel (DL-SCH) transport format and resource allocation, uplink shared channel (UL-SCH) resource allocation information, paging information on a paging channel (PCH), system DL-SCH information, higher layer control message resource allocation information, e.g., random access response transmitted on PDSCH, set of transmit power control commands on individual UEs in random UE group, transmit power control command, voice over IP activation information (VoIP), etc. Several PDCCHs may be transmitted in the control area. The UE may monitor multiple PDCCHs. The PDCCH is transmitted on an aggregation of one or more consecutive Control Channel Elements (CCEs). The CCE is a logical allocation unit used to provide the PDCCH with a coding rate based on the state of the radio channel. A CCE corresponds to several Resource Element Groups (REGs). The PDCCH format and the number of bits of the available PDCCH are determined by the number of CCEs. The BS determines the PDCCH format according to the DCI to be transmitted to the UE and appends a cyclic redundancy check (CRC) to the control information. The CRC is masked with a unique identifier (referred to as Radio Network Temporary Identifier (RNTI)) according to the owner or usage of the PDCCH. If the PDCCH is for a specific UE, the unique identifier (eg, cell RNTI (C-RNTI)) of the UE may mask the CRC. Alternatively, if the PDCCH is for a paging message, the paging identifier (eg, paging RNTI (P-RNTI)) may mask the CRC. If the PDCCH is for system information (particularly a system information block (SIB)), RNTI system information (SI-RNTI) may mask the CRC. When the PDCCH is for a random access response, the random access RNTI (RA-RNTI) may mask the CRC.

[0053] The PDCCH carries a message, known as a DCI, that includes resource assignment information and other control information for a UE or a group of UEs. In general, multiple PDCCHs may be transmitted in a subframe. Each PDCCH is transmitted using one or more CCEs. Each CCE corresponds to 9 sets of 4 REs. 4 RE are referred to as REG. 4 QPSK characters are mapped to one REG. The REs allocated to the reference signal are not included in the REG, and thus the total number of REGs in the OFDM symbols depends on the presence or absence of the cell-specific reference signal. The concept of REG (ie, group mapping, each group including 4 REs) is used for other downlink control channels (PCFICH and PHICH). Thus, the REG is used as the basic resource unit of the control zone. 4 PDCCH formats are supported as shown in Table 2.

[0054] Table 2

PDCCH Format Number of CCEs (n) Number of REGs Number of PDCCH bits 0 one 9 72 one 2 eight 144 2 four 36 288 3 5 72 576

[0055] The CCEs are numbered sequentially. To simplify the decoding process, transmission of a PDCCH having a format including n CCEs may be started using CCEs in multiples of n. The number of CCEs used to transmit a particular PDCCH is determined by the BS according to the channel condition. For example, if the PDCCH is intended for a UE having a high quality downlink channel (eg, a channel close to the BS), only one CCE may be used to transmit the PDCCH. However, for a UE having a weak channel (eg, a channel near a cell boundary), 8 CCEs may be used for PDCCH transmission to obtain sufficient reliability. In addition, the power level of the PDCCH can be controlled according to the channel condition.

[0056] LTE defines CCE positions in a limited set in which PDCCHs can be located for each UE. The positions of the CCEs in the restricted set that the UE must track in order to discover its assigned PDCCH may be referred to as a search space (SS). In LTE, the SS size is dependent on the PDCCH format. A UE-specific search space (USS) and a common search space (CSS) are set separately. The USS is set per UE and the CSS range is signaled to all UEs. USS and CSS may overlap for a given UE. In the case of a significantly small SS relative to a particular UE, when the same CCE positions are allocated to the SS, there are no other CCEs. Accordingly, the BS may not find the CCE resources on which PDCCHs will be transmitted to existing UEs in these subframes. In order to minimize the likelihood that this lock transitions to the next subframe, a UE-specific switching sequence is applied to the starting point of the USS.

[0057] Table 3 shows the CSS and USS sizes.

[0058] Table 3

PDCCH Format Number of CCEs (n) Number of candidates in the total search space Number of candidates in a special search space 0 one - 6 one 2 - 6 2 four four 2 3 eight 2 2

[0059] In order to control the computational load of blind decoding based on the number of blind decoding processes to an appropriate level, the UE does not need to simultaneously search for all given DCI formats. In general, the UE always looks for formats 0 and 1A in the USS. Formats 0 and 1A are the same size and differ from each other by a flag in the message. The UE may be required to receive an additional format (eg, format 1, 1B, or 2 according to the PDSCH transmission mode set by the BS). UE looks for 1A and 1C formats in CSS. In addition, the UE may be configured to search for format 3 or 3A. Formats 3 and 3A have the same size as formats 0 and 1A and can be distinguished from each other by scrambling the CRCs with different (common) identifiers instead of a UE specific identifier. The following are the PDSCH transmission schemes and the content of the DCI formats according to the transmission mode (TM).

[0060] Transfer Mode (TM)

[0061] Transmission mode 1: transmission from a single antenna port of the base station

[0062] Transmission mode 2: transmission diversity

[0063] Transmission Mode 3: Spatial Open Loop Multiplexing

[0064] Transmission mode 4: closed loop spatial multiplexing

[0065] Transmission mode 5: multi-user MIMO (multiple inputs and multiple outputs)

[0066] Transmission mode 6: closed loop precoding1 rank

[0067] Transmission mode 7: transmission via a single antenna port (port 5)

[0068] Transmission mode 8: bi-level transmission (ports 7 and 8) or transmission through a single antenna port (port 7 or 8)

[0069] Transmission mode 9: transmission through up to 8 layers (ports 7-14) or transmission through a single antenna port (port 7 or 8)

[0070] DCI Format

[0071] Format 0: resource grants for PUSCH transmission

[0072] Format 1: Resource Assignments for PDSCH Transmission of a Single Codeword (Transmission Modes 1, 2, and 7)

[0073] Format 1A: Compact signaling of resource assignments for a single PDSCH codeword (all modes)

[0074] Format 1B: Compact Resource Assignments for PDSCH Using Rank 1 Loop Precoding (Mode 6)

[0075] Format 1C: very compact resource assignments for PDSCH (eg, paging/broadcast system information)

[0076] 1D Format: Compact Resource Assignments for PDSCH Using Multi-User MIMO (Mode 5)

[0077] Format 2: PDSCH Resource Assignments for Closed Loop MIMO Operation (Mode 4)

[0078] Format 2A: PDSCH Resource Assignments for Open Loop MIMO Operation (Mode 3)

[0079] 3/3A Format: Power Control Commands for PUCCH and PUSCH with 2-bit/1-bit Power Controls

[0080] FIG. 5 shows EPDCCH. EPDCCH is a channel additionally introduced in LTE-A.

[0081] Referring to FIG. 5, the PDCCH (conventionally, legacy PDCCH or L-PDCCH) according to legacy LTE may be allocated to the control area (see FIG. 4) of a subframe. In the figure, the L-PDCCH area means an area to which the legacy PDCCH can be allocated. In doing so, the PDCCH may be further allocated to a data zone (eg, a resource zone for the PDSCH). The PDCCH allocated to the data zone is referred to as the E-PDCCH. As shown, control channel resources can be additionally acquired via the E-PDCCH to ease the scheduling constraint due to the limited control channel resources of the L-PDCCH area. Like L-PDCCH, E-PDCCH carries DCI. For example, the E-PDCCH may carry downlink scheduling information and uplink scheduling information. For example, the UE may receive the E-PDCCH and receive control data/information via the PDSCH corresponding to the E-PDCCH. In addition, the UE may receive the E-PDCCH and transmit control data/information via the PUSCH corresponding to the E-PDCCH. The E-PDCCH/PDSCH may be allocated starting from the first OFDM symbol of the subframe according to the cell type. In this specification, the PDCCH includes both the L-PDCCH and the EPDCCH unless otherwise noted.

[0082] FIG. 6 shows the structure of an uplink subframe used in LTE(-A).

[0083] Referring to FIG. 6, subframe 500 consists of two 0.5 ms slots 501. Assuming the length of a normal cyclic prefix (CP), each slot consists of 7 symbols 502, and one symbol corresponds to one SC-FDMA symbol. A resource block (RB) 503 is a resource allocation unit corresponding to 12 subcarriers in the frequency domain and one slot in the time domain. The uplink subframe structure of LTE(-A) is mostly divided into a data area 504 and a control area 505. The data zone refers to a communication resource used for data transmission, eg, voice, packets, etc., transmitted to each UE, and includes a physical uplink shared channel (PUSCH). The control area refers to a communication resource for transmitting an uplink control signal, such as a downlink channel quality report from each UE, receiving an ACK/NACK for a downlink signal, an uplink scheduling request, and so on. and includes a Physical Uplink Control Channel (PUCCH). The sounding reference signal (SRS) is transmitted via the SC-FDMA symbol, which is located last on the time axis in one subframe. The SRSs of multiple UEs that are transmitted by the last SC-FDMA of the same subframe may differ according to frequency positions/sequences. The SRS is used to transmit the uplink channel state to the eNB, and is periodically transmitted according to a subframe period/offset set by a higher layer (eg, RRC layer), or transmitted aperiodically upon request by the eNB.

[0084] FIG. 7 shows SC-FDMA and OFDMA schemes. The 3GPP system uses OFDMA on the downlink and uses SC-FDMA on the uplink.

[0085] Referring to FIG. 7, both UEs for transmitting an uplink signal and BSs for transmitting a downlink signal include a serial-to-parallel converter 401, a subcarrier mapping unit 403, an M-point IDFT unit 404, and a cyclic prefix (CP) adding unit 406 . The UE for signaling according to SC-FDMA further includes an N-point DFT module 402.

[0086] Next, HARQ (Hybrid Automatic Repeat Request) will be described. When there are multiple UEs having data to be transmitted on the uplink/downlink in wireless communication, the eNB selects the UE that will transmit data for each transmission time interval (TTI) (eg, subframe). In a system using multiple carriers, etc., the eNB selects a UE to transmit data on the uplink/downlink for each TTI, and also selects the frequency band to be used for data transmission of the respective UEs.

[0087] When the description is based on the uplink (UL), the UEs transmit reference signals (or pilot signals) on the uplink, and the eNB detects the channel states of the UE using the reference signals transmitted from the UE, and selects a UE to be transmit data on the uplink in each unit frequency band for each TTI. The eNB notifies the UE of the selection result. Thus, the eNB transmits, to the UEs scheduled for the UL, a UL assignment message indicating that the UEs can transmit data using a particular frequency band in a particular TTI. The UL assignment message is also referred to as a UL grant. The UEs transmit data on the uplink according to the UL assignment message. The UL assignment message may include a UE identifier (ID), RB allocation information, modulation and coding scheme (MCS), redundancy version (RV), new data indication (NDI), etc.

[0088] In the case of synchronous HARQ, a retransmission time is assigned in the system (eg, after 4 subframes from the NACK reception time) (synchronous HARQ). Accordingly, the eNB may send the UL grant message to the UE only in the initial transmission and subsequent retransmission is performed according to the ACK/NACK signal (eg, the PHICH signal). In the case of asynchronous HARQ, no retransmission time is assigned and thus the eNB must send a retransmission request message to the UE. Additionally, the frequency resources or MCS for the retransmission are identical to the frequency resources in the previous transmission in the case of non-adaptive HARQ, while the frequency resources or MCS for the retransmission may be different from the frequency resources in the previous transmission in the case of adaptive HARQ. For example, in the case of asynchronous adaptive HARQ, the retransmission request message may include the UE ID, RB allocation information, HARQ process ID/number, RV information, and NDI since the frequency resources or MCS for retransmission change according to the transmission time.

[0089] FIG. 8 shows UL HARQ operation in an LTE(-A) system. In the LTE(-A) system, asynchronous adaptive HARQ is used as UL HARQ. When using 8-channel HARQ, 0 to 7 are provided as HARQ process numbers. One HARQ process is valid for each TTI (eg, subframe). According to FIG. 8, the UL grant is transmitted to UE 120 on the PDCCH (S600). UE 120 transmits UL data to eNB 110 after 4 subframes from the time (eg, subframe 0) when the UL grant is received using the RB and MCS indicated by the UL grant (S602). eNB 110 decodes the UL data received from UE 120 and then generates ACK/NACK. In case of unsuccessful decoding of the UL data, the eNB 110 transmits a NACK to the UE 120 (S604). UE 120 retransmits the UL data after 4 subframes from the NACK reception time (S606). The initial transmission and retransmission of UL data are performed by the same HARQ process (eg, HARQ process 4). ACK/NACK information may be sent on the PHICH.

[0090] Scheduling for UL transmission in LTE is provided only in case of user equipment UL transmission timing synchronization. The random access procedure is used for various use cases. For example, the random access procedure is performed in case of initial network access, handover, data occurrence, and the like. The user equipment has the ability to obtain UL synchronization through a random access procedure. Upon receiving the UL synchronization, the base station is able to allocate a resource for UL transmission to the corresponding user equipment. The random access procedure can be classified into an adversarial procedure and an adversarial procedure.

[0091] FIG. 9 shows a diagram of one example of an adversarial random access procedure.

[0092] Referring to FIG. 9, the user equipment receives random access information from the base station via system information. Thereafter, if random access is needed, the user equipment transmits a random access preamble (or message 1) to the base station [S710]. After the base station receives the random access preamble from the user equipment, the base station sends a random access response message (or message 2) to the user equipment [S720]. In particular, the DL scheduling information on the Random Access Response message can be transmitted on the L1/L2 Control Channel (PDCCH) by masking the CRC with RA-RNTI (Random Access RNTI). Upon receiving the DL scheduling signal masked by the RA-RNTI, the user equipment receives a random access response message on the PDSCH and can then decode the received random access response message. Then, the user equipment checks whether the random access response information indicated on the user equipment is included in the received random access response message. Here, the presence or absence of random access response information indicated on the user equipment can be checked by checking whether a RAID (Random Access Preamble ID) is present for the preamble transmitted by the user equipment. The random access response information may include timing advance indicating timing offset information for synchronization, radio resource allocation information on a resource used on the UL, a temporary identifier (eg, T-RNTI) for identifying a user equipment (UE), and the like. random access, the user equipment sends a UL message (or message 3) on the UL SCH (Uplink Shared Channel) according to the radio resource allocation information included in the received random access response information [S730]. Upon receiving the UL message from the user equipment in step S730, the base station sends a contention resolution message (or message 4) to the user equipment [S740].

[0093] FIG. 10 shows a diagram of one example of a contention-free random access procedure. The non-contention random access procedure may be used in the handover procedure or may exist upon request in the order specified by the base station. The main procedure is suitable as an adversarial random access procedure.

[0094] Referring to FIG. 10, the user equipment receives assignment of a random access preamble (ie, a dedicated random access preamble) for the user equipment only from the base station [S810]. The random access special preamble indication information (eg, preamble index) may be included in the handover command message, or may be received on the PDCCH. The user equipment transmits a special random access preamble to the base station [S820]. Thereafter, the user equipment receives a random access response from the base station [S830], and the random access procedure ends.

[0095] To indicate a contention-free random access procedure by PDCCH order, the DCI 1A format is used. The DCI 1A format may be used for compact scheduling for one PDSCH codeword. The following information is transmitted using the DCI 1A format.

[0096] - Flag for identifying DCI format 0 or DCI format 1A: This flag is a 1-bit flag. A flag value of '0' indicates DCI format 0, and a flag value of '1' indicates DCI format 1A.

[0097] If all the fields remaining after scrambling the DCI 1A format CRC with the C-RNTI are set as follows, the DCI 1A format can be used for the random access procedure according to the PDCCH order.

[0098] - Localized/Distributed VRB (Virtual Resource Block) Assignment Flag: This flag is a 1-bit flag. This flag is set to 0.

. Каждый бит устанавливается равным 1.[0099] - Resource block assignment information:

. Each bit is set to 1.

[00100] - Preamble Index: 6 bits

[00101] - PRACH mask index: 4 bits

[00102] - All other bits for DCI 1A compact PDSCH scheduling are set to 0.

[00103] FIG. 11 shows the uplink/downlink frame timing relationship.

[00104] Referring to FIG. 11, transmission of uplink radio frame number i starts up to (N _TA +N _TAoffset )*T _s seconds from the start of the corresponding downlink radio frame. In the case of an LTE system, 0≤N _TA ≤20512, N _TAoffset =0 in FDD, and N _TAoffset =624 in TDD. The N _Taoffset value is a value recognized in advance by the BS and the UE. If N _TA is indicated by the timing advance command during the random access procedure, the UE adjusts the transmission timing of the UL signal (eg, PUCCH/PUSCH/SRS) according to the above equation. The UL transmission timing is set to a multiple of 16T _s . The timing advance command indicates a UL timing change based on the current UL timing. The timing advance command T _A in the random access response is an 11-bit timing advance command and indicates the values 0, 1, 2,..., 1282, and the timing adjustment value is set to N _TA =T _A *16. In other cases, the timing advance instruction T _A is a 6-bit timing advance instruction, and indicates the values 0, 1, 2,..., 63 and the timing adjustment value is set to N _TA,new =N _TA,old +(T _A - 31)*16. The timing advance command received in subframe n is applied from the beginning of subframe n+6. In the case of FDD, as shown, the transmission timing of UL subframe n is advanced based on the start time of DL subframe n. In contrast, in the case of TDD, the transmission timing of UL subframe n is advanced based on the end time of DL subframe n+1 (not shown).

[00105] FIG. 12 shows a carrier aggregation (CA) communication system.

[00106] Referring to FIG. 12, multiple UL/DL component carriers (CCs) may be aggregated to support a wider UL/DL bandwidth. The CCs may be contiguous or non-contiguous in the frequency domain. The CC bands may be independently determined. It is possible to implement an asymmetric CA in which the number of UL CCs is different from the number of DL CCs. The control information can only be transmitted/received via a specific CC. This particular CC may be referred to as a primary CC and other CCs may be referred to as secondary CCs. For example, when inter-carrier scheduling (or inter-CC scheduling) is applied, the allocation PDCCH for the downlink may be transmitted on DL CC #0 and the corresponding PDSCH may be transmitted on DL CC #2. The term "component carrier" can be replaced by other equivalent terms (eg, "carrier", "cell", etc.).

[00107] For inter-CC scheduling, a carrier indicator field (CIF) is used. The presence or absence of CIF on the PDCCH may be determined by higher layer signaling (eg, RRC signaling) semi-statically and depending on the UE (or depending on the UE group). The basics of PDCCH transmission are given below.

[00108] CIF disabled: The PDCCH on a DL CC is used to allocate a PDSCH resource on the same DL CC or a PUSCH resource on an associated UL CC.

[00109] No CIF

[00110] CIF included: The PDCCH on a DL CC may be used to allocate a PDSCH or PUSCH resource on a particular DL/UL CC from a plurality of aggregated DL/UL CCs using the CIF.

[00111] DCI LTE format extended to have CIF

[00112] CIF corresponds to a fixed x-bit field (e.g., x=3) (when CIF is set)

[00113] CIF position is fixed regardless of DIC format size (when CIF is set)

[00114] When a CIF is present, the BS may allocate a tracking DL CC (set) to reduce UE BD complexity. For PDSCH/PUSCH scheduling, the UE may detect/decode the PDCCH only on the corresponding DL CCs. The BS may only transmit the PDCCH over the tracking DL CC (set). The tracking DL CC set may be set per UE, per UE group, or per cell.

[00115] FIG. 13 shows scheduling in multi-carrier aggregation. It is assumed that 3 DL CC is aggregated and DL CC A is set as PDCCH CC. DL CCs A~C may be referred to as serving CC, serving carrier, serving cell, etc. When CIF is disabled, each DL CC can only transmit the PDCCH that schedules the PDSCH corresponding to the DL CC without CIF according to the LTE PDCCH (non-inter-CC scheduling) rule. When CIF is provided via UE dependent (or UE group dependent or cell dependent) higher layer signaling, a particular CC (e.g. DL CC A) can transmit not only a PDCCH that schedules a PDSCH DL CC A but also PDCCHs that schedule PDSCH of other DL CCs using CIF (Cross Scheduling). The PDCCH is not transmitted on DL CC B and DL CC C.

[00116] In addition, in the millimeter wave (mmW) system, the signal wavelength is small, so that multiple antennas can be installed in the same area. For example, since the wavelength is 1 cm in the 30 GHz band, all 100 antenna elements can be installed in a 5×5 cm ² panel in the form of a two-dimensional array with a spacing of 0.5 λ (in wavelength). Thus, in a mmW system, multiple antenna elements are used to increase the beamforming gain (BF) to increase coverage or increase throughput.

[00117] In this regard, where each antenna element has a TXRU (transceiver) such that transmit power and phase can be adjusted for each antenna element, independent beamforming can be realized for each frequency resource. However, installing each TXRU in each of all 100 antenna elements is not cost effective. Thus, the mapping scheme of multiple antenna elements into one TXRU and the lobe adjustment direction with an analog phase shifter is considered. This analog beamforming scheme can only form one lobe direction in a full band, and has the disadvantage that a frequency selective lobe cannot be achieved. Thus, as an intermediate form between digital BF and analog BF, a hybrid BF can be considered in which B TXRU is mapped to Q antenna elements (B < Q). In this case, the number of lobe directions in which a lobe is simultaneously transmitted is limited to a number less than or equal to B, although it varies depending on the connection scheme between the B TXRU and the Q antenna elements.

[00118] FIG. 14 shows analog beamforming. According to FIG. 14, the transmitter can transmit a signal by changing the lobe direction over time (transmit beamforming). The receiver can also receive the signal by changing the lobe direction with time (accept beamforming). Over a period of time, (i) the transmit and receive lobe directions may simultaneously change over time, (ii) the transmit lobe direction may be fixed in time, although only the receive lobe direction may change over time, or (iii) the direction of the lobe receive may be fixed in time, although only the direction of the transmit lobe may change over time.

[00119] In the next generation RAT (radio access technology), a single subframe is considered to minimize data transmission delay. Fig. 15 shows the structure of a single subframe. In FIG. 15, the shaded area represents the DL control area, and the black area represents the UL control area. The white zone can be used for DL data transmission or UL data transmission. DL transmission and UL transmission are sequentially performed in a single subframe, and thus DL data can be transmitted and UL ACK/NACK can also be received in a subframe. Therefore, the time until the data is retransmitted when a data transmission error is generated is reduced, thus minimizing the final delay in data delivery.

[00120] As examples of single subframe types that can be configured/set, the following four subframe types can be considered. The corresponding periods are arranged in time sequence.

[00121] DL control period + DL data period + GP (guard period) + UL control period

[00122] DL control period + DL data period

[00123] DL control period+GP+UL data period+UL control period

[00124] DL control period+GP+UL data period

[00125] The PDFICH, PHICH, and PDCCH may be transmitted during the data control period, and the PDSCH may be transmitted during the DL data period. The PUCCH may be transmitted during the UL control period and the PUSCH may be transmitted during the UL data period. The GP provides a time interval in the process in which the BS and the UE switch from the transmit mode to the receive mode or in the process in which the BS and the UE switch from the receive mode to the transmit mode. Some OFDM symbols in a subframe during a switch from DL to UL may be set on the GP.

[00126] Embodiment

[00127] In the new RAT (NR) system environment, when CA is performed on multiple cells for a single UE, OFDM numerology (e.g., subcarrier spacing and OFDM symbol period based on subcarrier spacing) and beamforming operation (e.g., TX/RX ( analog or hybrid beamforming) to be applied and lobe tracking) may be differently configured for use on a cell (group) basis. In the above CA situation, it is necessary to consider the HARQ operation related to DL/UL data scheduling/transmission, the UL power control scheme, the lobe related information signaling method, the signaling mechanism for all UEs, etc.

[00128] [1] Transmission method of the UL control channel on which the UCI is carried

[00129] In an NR system environment, a UE capable of performing UL CA operation and a UE not capable of performing UL CA operation may coexist depending on the implementation and capabilities of the UE. Although the UE is capable of performing the UL CA operation, the performance of the UL transmission to the UE over several cells may be degraded due to, for example, UL coverage, power limitation, etc. In this connection, two transmission modes of the UL control channel (in which carried by UCI) in a CA situation. Specifically, 1) the UE may only transmit the UL Control Channel via a particular cell (eg, P-cell), or 2) the UE may be configured to transmit the UL Control Channel individually according to the cell. For clarity, although the HARQ-ACK (i.e., A/N) that is transmitted in response to the received DL data is basically explained, the same principle can also be applied to other UCIs, such as CSI, SR, etc.

[00130] (a) Mode 1: UL control channel to P-cell only

[00131] In Mode 1, it is possible to transmit multiple A/N (multi-cell A/N) feedback only through a specific cell (eg, P-cell) in response to DL data received in multiple cells. Alternative 1) The Multi-Cell A/N may be configured to transmit over a single UL Control Channel resource only, or Alternative 2) The Multi-Cell A/N may be configured to transmit over multiple UL Control Channel resources. In the case of Alternative 2, a) each of the multiple UL Control Channel resources may be configured to transmit an A/N only in response to data received in the cell, or b) each of the multiple UL Control Channel resources may be configured to transmit one or more A/ N in response to DL data received via a cell group (corresponding to a portion of the entire cell group) including one or more cells. In particular, the UL control channel resource for A/N transmission may be differently configured/allocated according to cell (a) or cell group (b). Therefore, (in the case of considering the operation of specifying the UL control channel resource information of the A/N carrier), it may indicate another UL control channel resource to a cell (a) or cell group (b) through a DL grant that performs DL data scheduling.

[00132] Meanwhile, in the case of transmitting multiple CSI feedback signals ('multi-cell CSI') on DL radio bearers of multiple cells, multiple CSI feedback signals can be configured to be transmitted only through a specific cell (eg, P-cell). Alternative 1) The multi-cell CSI may be configured to transmit over a single UL Control Channel resource only, or alternative 2) The multi-cell CSI may be configured to transmit over multiple UL Control Channel resources. In the case of Alternative 2, a) each of the multiple UL Control Channel resources may be configured to transmit a single CSI for a cell only, or b) each of the multiple UL Control Channel resources may be configured to transmit one or more CSIs for a cell group (corresponding to a portion of the entire cell group). ) including one or more cells. In particular, the UL control channel resource for CSI transmission may be differently configured/allocated according to cell (a) or cell group (b). Here, the SR can be configured to be transmitted over a single UL control channel resource or multiple UL control channel resources. In particular, a method for transmitting a quantized BSR (buffer status report) in multi-bit form over a single UL control channel resource or multiple UL control channel resources by quantizing the UE's UL buffer status using multiple bits can be considered.

[00133] (B) Mode 2: UL control channel in each cell

[00134] In Mode 2, the A/N (and/or CSI) feedback signal can be configured to be transmitted through the cell itself in response to DL data received in the cell.

[00135] It is possible to semi-statically specify a mode for effecting UL control channel transmission from mode 1 and mode 2 (and/or a scheme for effecting UL control channel transmission from from alternative 1 and alternative 2) via higher layer signaling (eg, RRC signaling). Alternatively, it is possible to dynamically specify a mode to effect UL control channel transmission from mode 1 and mode 2 via L1 signaling (eg, DL control channel transmission). The presence or absence of UL control channel transmission operation based on Mode 2 (and/or UL control channel transmission operation based on Mode 1 Alternative 2) may become a capability of the UE, which varies according to the UE implementation. The UE may report the capability information to the eNB at an appropriate time (eg, during initial access or RRC connection setup).

[00136] It is possible to set the same UL control channel transmission mode (or alternative schemes in mode 1) for another UCI (eg, A/N and CSI). Alternatively, the transmission mode of the UL control channel (or alternative schemes in mode 1) can be independently (differently) configured according to the UCI.

[00137] FIG. 16 shows the UCI transmission procedure according to mode 1, and FIG. 17 shows the UCI transmission procedure according to mode 2. Referring to FIG. 16, the UE receives multiple DL data from multiple cells and is capable of transmitting multiple A/N ('multi-cell A/N') feedback only via a specific cell (eg, P-cell) in response to DL data received in multiple cells. Alternative 1) The Multi-Cell A/N may be configured to transmit over a single UL Control Channel resource only, or Alternative 2) The Multi-Cell A/N may be configured to transmit over multiple UL Control Channel resources. Fig. 16 shows a multi-cell A/N transmission procedure according to Alternative 2. Referring to FIG. 17, the UE receives multiple DL data from multiple cells and is capable of transmitting an A/N (and/or CSI) feedback signal through the cell itself in response to the DL data received in the cell.

[00138] [2] CA scheme between different OFDM numerologies

[00139] In an NR system environment, OFDM numerology (eg, subcarrier spacing and OFDM symbol duration (i.e., OS) based on subcarrier spacing) can be differently configured among multiple carrier cells aggregated at a single UE. Therefore, in a single UE aspect, the (absolute time) duration of the SF or TTI (collectively referred to as SF for clarity) may be differently configured between aggregated cells. With this in mind, in a CA situation between cells differing in SCS and OS duration, the operation method described below for the DL/UL data-related HARQ procedure (for example, when DL/UL data transmission in an S-cell is scheduled between CCs from P-cell, the A/N feedback signal is transmitted via the P-cell in response to the DL data received in the S-cell). In a CA situation between cells having the same SCS and OS duration, although the SF or TTI duration is differently configured between cells, the same principle can be applied.

[00140] (A) inter-CC scheduling between different SCS

[00141] FIG. 18 shows a case where a cell X having a long SCS (ie, a short OS duration or a short SF duration) is configured to schedule a Y cell having a small SCS (ie, a long OS duration or a long SF duration). According to FIG. 18, DL/UL data transmission in K (K>1) SF of cell X may be configured to be scheduled by one SF of cell Y. In this case, single SF of cell Y and K SF of cell X may have the same duration. In particular, case 1) when DL/UL grant for scheduling (maximum) K SF of cell X is transmitted/detected at the same time through the transmission zone of the DL control channel (in a single SF) of cell Y or case 2) when K transmission zones DL control channel in single SF of cell Y is independently configured, it is possible to transmit/detect DL/UL grant to schedule another SF in cell X through each area.

[00142] FIG. 19 shows a case where a cell X having a small SCS (i.e., a long OS duration or a large SF duration) is configured to schedule a Y cell having a large SCS (i.e., a small OS duration or a small SF duration). According to FIG. 19, DL/UL data transmission in a single SF of cell X may be configured to schedule all or part of (e.g., 1 SF) N (N>1) SFs of cell Y. In this case, N SFs of cell Y and a single SF of cell X may have the same length of time. In particular, option 1) providing DL/UL for scheduling a single SF of cell X is transmitted/discovered via an SF belonging to multiple SFs (i.e., a group of SFs) corresponding to all or part of the N SFs of cell Y (FIG. 19(a)) , or option 2) DL/UL grant for scheduling SF of cell X can be transmitted/discovered via a specific SF (eg, SF of cell Y overlapping with the first OS in SF of cell X in time) of N SF of cell Y (FIG. 19(b )). Here, in the case of Case 1, the timing of the SF with which the DL/UL grant is transmitted in the SF group may change, and each of the DL grant and the UL grant may be transmitted through another SF in the SF group. Therefore, the UE may sequentially perform a blind decoding operation in the DL control channel transmission areas of all SFs belonging to the SF group of cell Y. If all DL/UL grants for cell X are detected in the SF group of cell Y, the UE may not perform the blind decoding operation in the channel transmission areas. DL control in the remaining SF.

[00143] (B) HARQ-ACK timing for CA with different SCS

[00144] In a system CA situation, the NR, SCS, or OS duration (or TTI length) may be differently configured between a cell (eg, S-cell) in which DL data is transmitted and a cell (eg, P-cell), in which the A/N feedback signal is transmitted in response to the DL data. In this case, option 1) A/N timing (eg, delay between receiving DL data and transmitting A/N) may be configured based on the TTI length of the S-cell where DL data is transmitted, or option 2) A/N timing may be configured based on the length of the P-cell TTI where the A/N feedback signal is transmitted (eg, A/N timing (candidate set) is configured to be a multiple of the length of the P-cell TTI). For clarity, the A/N timing configured according to option 1/2 is referred to as 'A/N timing'. In the case of option 1, the actually applied actual P-cell A/N timing may be determined by timing overlapping with the timing occurring after the A/N temporal timing (e.g., the time corresponding to the N TTI of the S-cell) from the DL data reception timing or the first TTI (or UL control channel transmission duration (for A/N))) of the P-cell occurring after the A/N timing from the DL data reception timing of the S-cell. Here, in the case of option 2, the actually applied actual P-cell A/N timing may be determined by timing overlapping with the DL or TTI data reception timing (or UL control channel transmission duration (for A/N)) of the P-cell occurring after the A/N temporal timing (eg, the time corresponding to the M TTI of the P-cell) from the first TTI (or the transmission duration of the UL control channel (for A/N)) of the P-cell existing after the DL data reception timing of the S-cell.

[00145] Here, in the case of UL HARQ, the SCS or OS duration (or TTI length) may be differently configured between the cell (eg, P-cell) where the UL grant is transmitted and the cell (eg, S-cell), where the UL data is transmitted in response to the UL grant. In this case, option 1) HARQ timing (eg, delay between receiving the UL grant and transmitting UL data) may be configured based on the TTI length of the S-cell where the UL grant is transmitted (eg, HARQ timing (candidate set) configured to be a multiple of the TTI length P-cells) or option 2), the HARQ timing may be configured based on the TTI length of the S-cell where UL data is transmitted (eg, the HARQ (candidate set) timing is configured to be a multiple of the S-cell TTI length). For convenience, the HARQ timing configured according to option 1/2 is referred to as 'HARQ timing'. In the case of Option 1, the actually applied actual HARQ timing of the S-cell may be defined as the timing overlapped with the timing after the HARQ temporal timing (e.g., the time corresponding to the K TTI of the P-cell) from the UL grant reception timing in the P-cell, or the duration of the most early TTI (or UL data link transmission) of the S-cell, including the overlapping timing occurring thereafter. Here, in the case of Option 2, the actually applied actual S-cell HARQ timing may be defined as the duration of the TTI (or UL data link transmission) after the HARQ temporal timing (e.g., the time corresponding to the L TTI of the S-cell) from the timing overlapped with the timing receiving a UL grant at the P-cell, or the duration of the earliest TTI (or UL data link transmission) of the S-cell, including the overlapping timing occurring thereafter.

[00146] (C) UL TA (timing advance) control between different SCS

[00147] When CA is performed between cells operating with different SCSs, if a TA is used for UL timing negotiation, since the fetch time and CP length also differ according to different SCSs, it is difficult or impossible to apply the same TA value between cells operating with different SCS. Therefore, if a set of one or more cells to which the same TA value is applicable is defined as a TAG (Timing Advance Group), only cells operating with the same SCS can be configured as belonging to the TAG. It is possible to configure cells operating with different SCSs as not belonging to the same TAG. In addition, only cells operating with the same SCS and cells operating with the same CP length (CP length difference between cells is less than or equal to a specific layer) belonging to the TAG can be configured. It is possible to configure cells operating with different SCSs or different CP lengths (CP length difference between cells exceeds a certain level) as not belonging to the same TAG. Alternatively, cells may be configured for which the inter-cell SCS value difference (and/or the inter-cell CP length difference) is less than or equal to a specific layer belonging to the TAG. In particular, it is possible to configure cells for which the inter-cell SCS value difference (and/or the inter-cell CP length difference) exceeds a particular level as not belonging to the same TAG.

[00148] According to another method, in a state where there is no restriction to a separate TAG configuration, if cells operating with different SCSs are configured to belong to TAGs, a random access signal can be configured to determine a TA value to be transmitted by the cell operating with the largest SCS (i.e., e. the shortest access time and CP length) (or the cell configured with the largest random access signal SCS) among the cells belonging to the TAG. In addition, it is possible to configure the random access signal to transmit through the cell for which the shortest CP length is set only among the cells operating with the largest SCS (or cells configured with the largest random access signal SCS) in the same TAG.

[00149] When a Cell Group (UCIG) is configured to transmit a UL Control Channel (or UL Data Channel) carrying a UCI (e.g., A/N, CSI) on a specific set of cells (to which the cells belong) only via a specific (arbitrary) cell from cell set (i.e., the UL Control Channel carrying the UCI in the cells belonging to the UCIG is configured to transmit only through a specific UCIG cell), UCIG (and the cell in which the UL Control Channel (UCI) is transmitted) can be configured by applying the condition , identical to the TAG (and the cell on which the random access signal is transmitted). When a cell group (DCIG) is configured to transmit a DL control channel carrying a DCI (e.g., DL/UL scheduling grant) on a specific cell set (to which the cells belong) only via a specific cell of the cell set (i.e., inter-CC scheduling is configured to perform only between cells belonging to DCIG), DCIG can be configured by applying a condition identical to TAG. In particular, it is possible to configure the DCIG (and the cell on which the DL Control Channel (DCI) is transmitted) by applying the identical condition to the TAG (and the cell on which the random access signal is transmitted).

[00150] [3] Analog beamforming with CA scheme

[00151] In the case of an NR system operating in a particular frequency band (e.g., high carrier frequency), it is highly likely that the NR system performs (analog or hybrid) TX/RX beamforming on the DL/UL signal in the eNB (and/ or UE) based on the mmW characteristic. By way of example, the eNB transmits several specific (for all UEs) signals (e.g., synchronization signal or reference signal) differing in lobe direction for a certain period, and the UE informs the eNB of reception quality/status information (i.e., BSI (state information). lobe)) and/or preferred lobe information (eg, lobe ID or index) optimized for the UE receiving the particular signal (ie, lobe direction). The UE may perform a DL/UL signal transmission/reception operation based on beamforming based on the information. In this case, a lobe ID (or index) may correspond to an index for identifying (direction) a lobe formed by a combination of antenna ports different from each other. Meanwhile, in the case of an NR system operating in a particular frequency band (eg, at a low carrier frequency), it is likely that the NR system operates like a conventional system without applying the aforementioned beamforming. In particular, in the NR system environment, the case can be considered where CA is performed in a cell to which beamforming (BF) is applied (i.e., a cell with BF) and a cell to which beamforming (BF) is not applied (i.e., cell without BF) at the same time in the UE.

[00152] (A) CA between cell without BF and cell with BF

[00153] When CA is performed between a cell without BF and a cell with BF, the cell without BF can maintain relatively higher signal transmission reliability and coverage compared to a cell with BF. Therefore, in the case of a particular (eg, important) type of information, it is possible to configure the transmission to be performed only by a cell without a BF (UL data/control channel of a cell) (preferably by selecting a UL data/control channel of a cell without BF (to a cell with BF)). In this case, the specific type of information may include at least one selected from the group consisting of a response message received from the eNB in response to the RRC configuration, a response message received from the eNB in response to the MAC command, various reports (eg, power headroom report, buffer status report) using (based on event trigger and period scheme) MAC signal, and report related to RRM (Radio Resource Management) measurement.

[00154] Here, either cells without BFs or cells with BFs belonging to a single DCIG can be configured. In particular, it is possible to configure a cell without a BF and a cell with a BF that do not belong to the same DCIG. Alternatively, if the non-BF cell and the BF cell are configured to belong to a single DCIG without being limited to a separate DCIG configuration, a DL Control Channel (DCI) can be configured to be transmitted only over the non-BF cell. For this, at least one cell without BF belonging to DCIG can be configured. Similarly, either cells without BFs or cells with BFs belonging to a single UCIG can be configured. In particular, it is possible to configure a cell without a BF and a cell with a BF that do not belong to the same UCIG. In this case, if the cell without BF and the cell with BF are configured to belong to a single UCIG without being limited to a separate UCIG configuration, it is possible to configure the UL Control Channel (UCI) to transmit only through the cell without BF. For this, at least one cell without BF belonging to UCIG can be configured. Additionally, either cells without BFs or cells with BFs belonging to a single TAG may be configured. In particular, it is possible to configure a cell without a BF and a cell with a BF that do not belong to the same TAG. In this case, if the non-BF cell and the non-BF cell are configured to belong to a single TAG without being limited to a separate TAG configuration, the random access signal can be configured to be transmitted only through the non-BF cell. For this, at least one cell without BF can be configured to belong to the TAG.

[00155] Meanwhile, the UE may transmit a signal requesting the eNB to change the lobe ID, a signal informing the eNB of a TX/RX lobe mismatch status, a signal requesting the eNB to allocate a UL resource to transmit a BSI or BRI feedback signal in a cell with BF, a signal requesting the eNB to transmit the DL RS for lobe measurement/refinement, as well as the BSI feedback signal in the cell from the BF to the eNB via the cell without BF (the UL data/control channel of the corresponding cell) (for clarity, the above signals are referred to as ʺSR, associated with the petalʺ). The UE may report the measurement result for the DL RS to measure/refine the lobe transmitted via the BF cell to the eNB via the non-BF cell. The UE may signal whether a DL control channel (eg, DL/UL grant signal, DL/UL data channel scheduling, etc.) is detected to the eNB via a cell without a BF. For example, the UE may signal information on whether a DL control channel has been detected via a cell with BF for a specific duration or information on the number of DL control channels on an eNB via a cell without BF. When the UE operates in a cell with BF, the above operations are necessary because mismatch may occur on the TX/RX lobe according to the radio bearer status, and transmission of the DL/UL signal transmitted by the cell with BF in the status is unstable.

[00156] In this case, the operation proposed above may not be limited to CA between a cell without a BF and a cell with a BF. For example, the same operation may be applied in a state where a cell without BF and a cell with BF are replaced by a P-cell and an S-cell or a first cell and a second cell, respectively. More generally, the proposed operation can be applied in a state where a cell without BF and a cell with BF are considered as the first cell and the second cell different from each other or the only cell.

[00157] (B) Cell activation/deactivation with BF

[00158] Unlike a conventional cell without a BF, in the case of a cell with a BF, the (preferred) lobe ID may change during the deactivation period due to radio channel change, etc. With this in mind, the UE may configure the BF cell to perform BSI measurement and (preferred) lobe search by receiving a particular signal (eg, sync signal or reference signal) after cell activation with BF (and BSI eNB message and (preferred) lobe ID). Here, the UE may not perform another DL/UL signal transmission/reception operation in the cell with the BF until the above operation is completed.

[00159] According to another method, it is possible to configure the UE to perform lobe tracking (eg, BSI measurement, (preferred) lobe search) in a BF cell by receiving a specific signal (eg, synchronization signal or reference signal) during deactivation of the BF cell. Therefore, the UE may report the (recent) BSI and (preferred) lobe ID to the eNB while the cell with the BF is activated (via a response message in response to the activation message). Here, the eNB may initiate the RS to measure the BSI to be transmitted by an activation message for the cell with the BF, and/or instruct the UE to report the result of the BSI measurement.

[00160] Meanwhile, a cell without a BF typically performs a UL/DL signal transmission/reception operation during the activation period and does not perform a UL/DL signal transmission/reception operation during the deactivation period. For example, a cell without a BF does not receive a DL physical channel (eg, PDCCH, PHICH, etc.) during the deactivation period and does not perform a CSI/SRS transmission operation.

[00161] [4] UL power control in different CA situations

[00162] When CA is performed between cells operating with different SCSs (or different OS durations), if a UE maximum power limitation occurs (e.g., the sum of the UL (configured eNB) power exceeds the maximum UE power at the same timing), a preferential method can be considered. reducing the power of a UL channel/signal (cell) configured with a small SCS (or a long OS duration) and/or a method of assigning a minimum guaranteed power to a UL channel/signal (a cell) configured with a large SCS (or a short OS duration). For example, if the minimum guaranteed power for a particular UL channel/signal is given by G-power, and the power configured by the eNB is given by C-power, the final power (i.e., S-power) of the particular UL channel/signal calculated by the power scaling procedure in limiting the maximum power of the UE can only be determined by a value greater than or equal to min { G-power, C-power } (ie, the minimum value of S-power is limited to min { G-power, C-power }). Meanwhile, when a CA is performed between a cell without a BF and a cell with a BF, if a UE maximum power limitation occurs, a method for preferentially reducing the channel/UL signal power of the cell without BF and/or a method for assigning G-power to the UL channel/signal of the BF cell can be considered. .

[00163] Meanwhile, when UL channels/signals (e.g., UL data/control channel, UL sounding signal) differing in the number of symbols (or differing in time length) are transmitted at the same time, if a maximum UE power limitation occurs, it is possible consider a method of preferentially reducing the power of a UL channel/signal having more symbols (or a longer duration) and/or a method of assigning a minimum guaranteed power to a UL channel/signal having fewer symbols (or a shorter duration). Meanwhile, when UL channels/signals (e.g., UL data/control channel, UL sounding signal to which different UL modulation schemes are applied (e.g., OFDM or DFT-based SC-FDM) are transmitted at the same time, it can be considered a method for preferentially reducing the power of the UL channel/signal to which the OFDM scheme is applied; and/or a method for assigning a minimum guaranteed power to the UL channel/signal to which the SC-FDM scheme is applied.

[00164] The method proposed above can be applied considering power scaling priority (e.g., power down in the order random access signal > control channel > data channel > sounding signal) between UL channels/signals and power scaling priority between UCI types (e.g., power down in the order A/N > SR > CSI, A/N=SR > CSI or SR > A/N > CSI). For example, power scaling is performed according to the priority between UL channels/signals and the priority between UCI types after preferential application of the proposed scheme. Alternatively, the proposed scheme is applied between channels/signals and UCI types having the same priority after performing power scaling according to the priority between UL channels/signals and the priority between UCI types.

[00165] In doing so, it is possible to assign a power scaling priority higher than the priority of another UCI type (eg, A/N, CSI) to the SR associated with the lobe (regardless of whether a CA is configured). For example, if a UE maximum power limitation occurs, it may be preferable to reduce the signal power of another type of UCI compared to the SR associated with the lobe signal. In particular, a power scaling priority (equal to or) lower than A/N is assigned to a common data SR requesting a data transmission resource UL. On the contrary, it is possible to assign a power scaling priority higher than the A/N SR associated with the lobe. As another example, although a power scaling priority lower than the random access signal is assigned to the common data SR, it is possible to assign a power scaling priority higher than the random access signal of the SR associated with the lobe. Meanwhile, the random access signal (contention) resource that the UE can select/transmit in the initial access mode or the sleep mode (to prevent excessive contention and congestion in a random access situation), and the random access signal (contention) signal resource that the UE can select /transmit (to request scheduling) in the connection mode can be configured to differ from each other in time/frequency/code.

[00166] [5] A method for implementing a CA including a non-autonomous S-cell

[00167] In an NR system environment, an S-cell configuring a CA may act as autonomous or non-autonomous. In particular, when implementing a CA involving a non-autonomous S-cell, 1) the eNB may aperiodically initiate transmission of a particular (for all UEs) signal (e.g., synchronization signal, system information, or reference signal) in the S-cell, and 2) the UE may aperiodically request the transmission of a specific signal. When the (potential or candidate) timing and the period suitable for transmitting a specific signal is configured in advance, in the presence of an eNB trigger signal transmission or a UE request signal transmission for a specific signal by random timing, a method of transmitting and receiving a triggered/requested specific signal by timing and the period closest to the transmission timing of the trigger/request signal (or the timing to which the specific time offset is added). In this case, the eNB's originating signal or the UE's request signal for a specific signal may be transmitted via a cell (eg, P-cell) operating in the autonomous mode.

[00168] In this case, in the case of an autonomous cell, the transmission of a specific (for all UEs) signal (for example, a synchronization signal, specific partial system information (except for information necessary for performing the initial access stage/procedure ((for example, a random access signal/ resource configuration)) reference signal, etc.) may be initiated/requested aperiodically by the eNB or UE.In this case, the method proposed above can be applied identically.More generally, the proposed method is not limited to a CA between an autonomous cell and a non-autonomous cell The same operation can be applied in a state where an autonomous cell and a non-autonomous cell are replaced by a P-cell and an S-cell, or a first cell and a second cell, respectively.More generally, the proposed method can be applied in a state where the autonomous cell and a non-autonomous cell is considered as a first cell and a second cell different from each other or a single cell.

[00169] Here, either autonomous cells (ie, SA cells) or non-autonomous cells (ie, NSA cells) can be configured to belong to a single DCIG. In particular, it is possible to configure an SA cell and an NSA cell as not belonging to the same DCIG. On the other hand, if the SA cell and the NSA cell are configured to belong to a single DCIG without being limited to a separate DCIG configuration, a DL Control Channel (DCI) can be configured to be transmitted only via the SA cell. For this, at least one SA cell belonging to the DCIG can be configured. Similarly, either SA cells or NSA cells can be configured to belong to a single UCIG. In particular, it is possible to configure the SA cell and the NSA cell as not belonging to the same UCIG. In this case, if the SA cell and the NSA cell are configured to belong to a single UCIG without being limited to a separate UCIG configuration, it is possible to configure the UL Control Channel (UCI) to be transmitted only via the SA cell. For this, at least one SA cell belonging to UCIG can be configured. Additionally, either SA cells or NSA cells can be configured to belong to a single TAG. In particular, it is possible to configure an SA cell and an NSA cell as not belonging to the same TAG. In this case, if the SA cell and the NSA cell are configured to belong to a single TAG without being limited to a separate TAG configuration, the random access signal can be configured to be transmitted only via the SA cell. To do this, you can configure at least one SA-cell belonging to the TAG.

[00170] Meanwhile, when a single cell or carrier is divided into multiple subbands, and an SCS or TTI of a different size is set to each of the multiple subbands, although the UE operates on multiple subbands at the same time or switches between subbands, all the proposed methods of the present invention can be similarly applied ( by changing the cell in the subband).

[00171] FIG. 20 shows BSs and UEs of wireless communication systems that are applicable to embodiments of the present invention.

[00172] Referring to FIG. 20, the wireless communication system includes a BS 110 and a UE 120. When the wireless communication system includes a relay, the BS or UE may be replaced by the relay.

[00173] BS 110 includes a processor 112, a memory 114, and a radio frequency (RF) unit 116. The processor 112 may be configured to implement the procedures and/or methods of the present invention. Memory 114 is coupled to processor 112 and stores information related to operations of processor 112. RF unit 116 is coupled to processor 112 and transmits and/or receives an RF signal. UE 120 includes a processor 122, a memory 124, and an RF unit 126. The processor 122 may be configured to implement the procedures and/or methods proposed by the present invention. Memory 124 is coupled to processor 122 and stores information related to operations of processor 122. RF unit 126 is coupled to processor 122 and transmits and/or receives an RF signal.

[00174] The following embodiments of the present invention are combinations of elements and features of the present invention. Elements or features can be considered selectively, unless otherwise indicated. Each element or feature can be practiced without being combined with other elements or features. Additionally, an embodiment of the present invention can be built by combining parts of elements and/or features. The orders of operations described in the embodiments of the present invention can be changed. Some constructs of any embodiment may be included in another embodiment and may be replaced by corresponding constructs of another embodiment. It will be appreciated by those skilled in the art that claims that are not explicitly set forth in the following claims in relation to each other may be presented together as an embodiment of the present invention or incorporated as a new claim by subsequent modification after filing.

[00175] According to the embodiments of the present invention, the description focuses on the ratio of data transmission and reception between the BS, the relay and the MS. In some cases, a particular operation described as being performed by a BS may be performed by an upper node of the BS. In particular, it will be appreciated that, in a network composed of several network nodes including BSs, the various operations performed to communicate with the MS may be performed by the BS or network nodes other than the BS. The term 'BS' can be replaced by 'fixed station', 'node B', 'extended node B (eNode B or eNB)', 'access point', etc. The term 'UE' can be replaced by 'Mobile Station (MS)', 'Mobile Subscriber Station (MSS)', 'Mobile Terminal', etc.

[00176] Embodiments of the present invention may be achieved by various means, such as hardware, firmware, software, or a combination thereof. In a hardware configuration, methods according to embodiments of the present invention may be achieved by one or more application specific integrated circuits (ASICs), digital signal processors (DSPs), digital signal processing devices (DSPDs), programmable logic devices (PLDs), field programmable gate arrays (FPGA), processors, controllers, microcontrollers, microprocessors, etc.

[00177] In a firmware or software configuration, embodiments of the present invention may be implemented in the form of a module, procedure, function, and so on. For example, program code may be stored in a memory unit and executed by a processor. The memory unit is located inside or outside the processor and can send and receive data to and from the processor through various known means.

[00178] Specialists in the art it is obvious that the present invention can be carried out in other specific ways in addition to those set forth here without departing from the essence and essential characteristics of the present invention. Thus, the above-described embodiments are to be considered in all respects as illustrative and not restrictive. The scope of the invention is to be determined by the following claims and their legal equivalents, and not by the foregoing description, and all changes within the meaning and range of equivalence of the following claims are to be incorporated.

INDUSTRIAL APPLICATION

[00179] The present invention is applicable to UEs, eNBs, or other devices in a wireless mobile communication system.

Claims (50)

1. A method for communicating by a user equipment (UE) in a wireless communication system, the method comprising: receiving a physical downlink control channel (PDCCH) signal in the n-th first slot among the first slots of the first cell, each of which has a duration related to the first subcarrier spacing; transmitting a Physical Uplink Shared Channel (PUSCH) signal corresponding to the PDCCH signal in the m-th second time slot among the second time slots of the second cell, each having a duration related to the second subcarrier spacing, the second cell being related to information carrier indicator of the PDCCH signal and the m-th second slot of the second cell refers to the delay time offset, wherein the m-th second slot of the second cell is defined as the m-th second slot after the delay time offset of the k-th second slot of the second cell, and the delay time offset is represented as the number of second slots of the second cell, and wherein the duration of each of the first time intervals is greater than the duration of each of the second time intervals, based on the fact that the first subcarrier spacing is less than the second subcarrier spacing, and the k-th second time interval of the second cell is the earliest of the plurality of second time intervals a second cell that spans the n-th first time interval of the first cell. 2. The method of claim 1, wherein the PDCCH signal is received via a first cell in the wireless communication system, and wherein the PUSCH signal is transmitted through a second cell in the wireless communication system that is different from the first cell. 3. The method of claim 1, wherein the PDCCH signal contains scheduling information, and wherein the PUSCH signal is transmitted in the m-th second slot based on the scheduling information in the PDCCH signal. 4. The method of claim 1, wherein each of the first time slots comprises a first set of Orthogonal Frequency Division Multiplexing (OFDM) symbols, and wherein each of the second time slots comprises a second set of Orthogonal Frequency Division Multiplexing (OFDM) symbols. 5. User equipment (UE) configured to communicate in a wireless communication system, comprising: at least one processor; and at least one computer memory operatively coupled to at least one processor and storing instructions that, when executed, cause at least one processor to perform operations comprising: receiving a physical downlink control channel (PDCCH) signal in an n-th first slot among the first slots of the first cell, each having a duration related to the first subcarrier spacing; transmission of a physical uplink shared channel (PUSCH) signal corresponding to the PDCCH signal in the m-th second time interval among the second time intervals of the second cell, each of which has a duration related to the second subcarrier spacing, the second cell being related to information carrier indicator of the PDCCH signal and the m-th second slot of the second cell refers to the delay time offset, wherein the m-th second slot of the second cell is defined as the m-th second slot after the delay time offset of the k-th second slot of the second cell, and the delay time offset is represented as the number of second slots of the second cell, and wherein the duration of each of the first time intervals is greater than the duration of each of the second time intervals, based on the fact that the first subcarrier spacing is less than the second subcarrier spacing, and the k-th second time interval of the second cell is the earliest of the plurality of second time intervals a second cell that spans the n-th first time interval of the first cell. 6. The UE of claim 5, wherein the PDCCH signal is received via the first cell in the wireless communication system, and wherein the PUSCH signal is transmitted through a second cell in the wireless communication system that is different from the first cell. 7. The UE of claim 5, wherein the PDCCH signal contains scheduling information, and wherein the PUSCH signal is transmitted in the m-th second slot based on the scheduling information in the PDCCH signal. 8. The UE of claim 5, wherein each of the first slots comprises a first set of Orthogonal Frequency Division Multiplexing (OFDM) symbols, and wherein each of the second time slots comprises a second set of Orthogonal Frequency Division Multiplexing (OFDM) symbols. 9. The UE of claim 5, further comprising at least one radio frequency (RF) module. 10. A method for communicating by a base station (BS) in a wireless communication system, the method comprising: transmitting a physical downlink control channel (PDCCH) signal in the n-th first time interval among the first time intervals of the first cell, each having a duration related to the first subcarrier spacing; receiving a Physical Uplink Shared Channel (PUSCH) signal corresponding to the PDCCH signal in the m-th second time slot among the second time slots of the second cell, each having a duration related to the second subcarrier spacing, the second cell being related to information carrier indicator of the PDCCH signal and the m-th second slot of the second cell refers to the delay time offset, wherein the m-th second slot of the second cell is defined as the m-th second slot after the delay time offset of the k-th second slot of the second cell, and the delay time offset is represented as the number of second slots of the second cell, and wherein the duration of each of the first time intervals is greater than the duration of each of the second time intervals, based on the fact that the first subcarrier spacing is less than the second subcarrier spacing, and the k-th second time interval of the second cell is the earliest of the plurality of second time intervals a second cell that spans the n-th first time interval of the first cell. 11. The method of claim 10, wherein the PDCCH signal is transmitted via a first cell in the wireless communication system, and wherein the PUSCH signal is received via a second cell in the wireless communication system that is different from the first cell. 12. The method of claim 10, wherein the PDCCH signal contains scheduling information, and wherein the PUSCH signal is received in the m-th second slot based on the scheduling information in the PDCCH signal. 13. The method of claim 10, wherein each of the first time slots comprises a first set of Orthogonal Frequency Division Multiplexing (OFDM) symbols, and wherein each of the second time slots comprises a second set of Orthogonal Frequency Division Multiplexing (OFDM) symbols. 14. A base station (BS) configured to communicate in a wireless communication system, comprising: at least one processor; and at least one computer memory operatively coupled to at least one processor and storing instructions that, when executed, cause at least one processor to perform operations comprising: transmitting a physical downlink control channel (PDCCH) signal in an n-th first slot among the first slots of the first cell, each having a duration related to the first subcarrier spacing; receiving a Physical Uplink Shared Channel (PUSCH) signal corresponding to the PDCCH signal in the m-th second time slot among the second time slots of the second cell, each of which has a duration related to the second subcarrier spacing, wherein the second cell refers to information carrier indicator of the PDCCH signal and the m-th second slot of the second cell refers to the delay time offset, wherein the m-th second slot of the second cell is defined as the m-th second slot after the delay time offset of the k-th second slot of the second cell, and the delay time offset is represented as the number of second slots of the second cell, and wherein the duration of each of the first time intervals is greater than the duration of each of the second time intervals, based on the fact that the first subcarrier spacing is less than the second subcarrier spacing, and the k-th second time interval of the second cell is the earliest of the plurality of second time intervals a second cell that spans the n-th first time interval of the first cell. 15. The BS of claim 14, wherein the PDCCH signal is transmitted via the first cell in the wireless communication system, and wherein the PUSCH signal is received via a second cell in the wireless communication system that is different from the first cell. 16. The BS of claim 14, wherein the PDCCH signal contains scheduling information, and wherein the PUSCH signal is received in the m-th second slot based on the scheduling information in the PDCCH signal. 17. The BS of claim 14, wherein each of the first slots comprises a first set of Orthogonal Frequency Division Multiplexing (OFDM) symbols, and wherein each of the second time slots comprises a second set of Orthogonal Frequency Division Multiplexing (OFDM) symbols. 18. BS according to claim 14, also containing at least one radio frequency (RF) module.

Images