JP2017022538A - Terminal device, base station device and communication method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To efficiently control a cell which uses a non-assigned frequency band or a sharing frequency band.SOLUTION: A terminal device includes a receiver unit which acquires time and frequency synchronization with a cell on the basis of a primary synchronous signal, a first secondary synchronous signal and a second secondary synchronous signal. When there is no setting to the cell in regard to the second secondary synchronous signal, the terminal device acquires synchronization on the basis of the primary synchronous signal and the first secondary synchronous signal, whereas when there is setting to the cell in regard to the second secondary synchronous signal, the terminal device acquires synchronization on the basis of the primary synchronous signal and the second secondary synchronous signal. A plurality of first resource elements to which the second secondary synchronous signal is mapped are different from a plurality of second resource elements to which the first secondary synchronous signal is mapped.SELECTED DRAWING: Figure 4

Description

  Embodiments described herein relate generally to a terminal device, a base station device, and a communication method that realize efficient communication.

  In the standardization project 3GPP (3rd Generation Partnership Project), Evolv realized high-speed communication by adopting OFDM (Orthogonal Frequency-Division Multiplexing) communication method and flexible scheduling in a predetermined frequency and time unit called resource block The standardization of Universal Terrestrial Radio Access (hereinafter referred to as E-UTRA) has been carried out.

  Further, 3GPP is studying Advanced E-UTRA that realizes higher-speed data transmission and has upward compatibility with E-UTRA. In E-UTRA, a base station apparatus is a communication system on the premise of a network having substantially the same cell configuration (cell size). However, in Advanced E-UTRA, base station apparatuses (cells) having different configurations have the same area. A communication system based on a mixed network (heterogeneous wireless network, heterogeneous network) is being studied. Note that E-UTRA is also referred to as LTE (Long Term Evolution), and Advanced E-UTRA is also referred to as LTE-Advanced. LTE can also be a generic name including LTE-Advanced.

  In a communication system in which a cell having a large cell radius (macro cell) and a cell having a cell radius smaller than the macro cell (small cell, small cell) are arranged as in a heterogeneous network, the terminal device includes a macro cell and a small cell. Carrier aggregation (CA) technology and dual connectivity (DC) technology for simultaneous communication and communication are defined (Non-patent Document 1).

  On the other hand, Non-Patent Document 2 discusses license-assisted access (LAA). In LAA, for example, an unallocated frequency band (Unlicensed spectrum) used by a wireless LAN (Local Area Network) is used as LTE. Specifically, an unassigned frequency band is set as a secondary cell (secondary component carrier). The secondary cell used as the LAA is assisted with respect to connection, communication and / or setting by a primary cell (primary component carrier) set in an allocated frequency band (Licensed spectrum). LAA expands the frequency band that can be used in LTE, thereby enabling broadband transmission. Note that LAA is also used in a shared spectrum shared between predetermined operators.

3rd Generation Partnership Project; Technical Specification Group Radio Access Network; Evolved Universal Terrestrial Radio Access (E-UTRA); Physical layer procedures (Release 12), 3GPP TS 36.213 V12.4.0 (2014-12). 3rd Generation Partnership Project; Technical Specification Group Radio Access Network; Study on Licensed-Assisted Access to Unlicensed Spectrum; (Release 13) 3GPP TR 36.889 V1.0.1 (2015-6).

  In LAA, if an unassigned frequency band or a shared frequency band is used, that frequency band will be shared with other systems and / or other operators. However, LTE is designed on the assumption that it is used in an allocated frequency band or a non-shared frequency band. Therefore, the conventional LTE cannot be used in the unassigned frequency band or the shared frequency band.

  The present invention has been made in view of the above points, and an object of the present invention is to provide a terminal device, a base station device, and a communication method capable of efficiently controlling a cell using an unassigned frequency band or a shared frequency band. Is to provide.

  (1) In order to achieve the above object, the present invention takes the following measures. That is, a terminal apparatus according to an embodiment of the present invention includes a receiving unit that acquires time and frequency synchronization with a cell based on a primary synchronization signal, a first secondary synchronization signal, and a second secondary synchronization signal. When the terminal device is not set for the second secondary synchronization signal for the cell, synchronization is acquired based on the primary synchronization signal and the first secondary synchronization signal, and the second secondary synchronization is performed for the cell. When the setting related to the signal is made, synchronization is acquired based on the first primary synchronization signal and the second secondary synchronization signal, and the plurality of first resource elements to which the second secondary synchronization signal is mapped are the first Different from the plurality of second resource elements to which the secondary synchronization signal is mapped.

  (2) In addition, the terminal device according to an aspect of the present invention is the above-described terminal device, and the primary synchronization signal or the first secondary synchronization signal is arranged in the subframe period in which the second secondary synchronization signal is arranged. Longer than the subframe period.

  (3) Moreover, the terminal device according to an aspect of the present invention is the above-described terminal device, and the primary synchronization signal or the first secondary synchronization signal is arranged in the OFDM symbol in which the second secondary synchronization signal is arranged. Different from OFDM symbols.

  (4) A terminal device according to an aspect of the present invention is the above-described terminal device, wherein the second secondary synchronization signal is set for the LAA cell, and the second device is set for the cells other than the LAA cell. The secondary sync signal is not set.

  (5) Moreover, the terminal device by one aspect | mode of this invention is the above-mentioned terminal device, Comprising: The some 1st resource element to which a 2nd secondary synchronizing signal is mapped is based on a cell identifier.

  (6) Moreover, the base station apparatus by one aspect of this invention is a base station apparatus which communicates with a terminal device, Comprising: The transmission part which transmits a primary synchronizing signal, a 1st secondary synchronizing signal, and a 2nd secondary synchronizing signal Is provided. The base station apparatus transmits a primary synchronization signal and a first secondary synchronization signal to the terminal apparatus when the terminal apparatus is not set for the second secondary synchronization signal for the cell, and transmits a second synchronization signal to the terminal apparatus for the cell. When the setting related to the secondary synchronization signal is performed, the primary synchronization signal and the second secondary synchronization signal are transmitted, and the plurality of first resource elements to which the second secondary synchronization signal is mapped are the first secondary synchronization signal. Is different from the plurality of second resource elements to which is mapped.

  (7) Moreover, the base station apparatus by one aspect | mode of this invention is the above-mentioned base station apparatus, Comprising: The subframe period by which a 2nd secondary synchronizing signal is arrange | positioned is a primary synchronizing signal or a 1st secondary synchronizing signal. It is longer than the subframe period to be arranged.

  (8) In addition, a base station apparatus according to an aspect of the present invention is the above-described base station apparatus, and the primary synchronization signal or the first secondary synchronization signal is disposed in the OFDM symbol in which the second secondary synchronization signal is disposed. This is different from the OFDM symbol to be used.

  (9) A base station apparatus according to an aspect of the present invention is the base station apparatus described above, wherein the terminal apparatus is configured for the second secondary synchronization signal for the LAA cell, and the terminal apparatus is configured with the LAA. Settings relating to the second secondary synchronization signal are not performed for cells other than the cell.

  (10) A base station apparatus according to an aspect of the present invention is the base station apparatus described above, and the plurality of first resource elements to which the second secondary synchronization signal is mapped are based on a cell identifier.

  (11) A communication method according to an aspect of the present invention is a communication method used in a terminal device, and is based on a primary synchronization signal, a first secondary synchronization signal, and a second secondary synchronization signal. Obtaining time and frequency synchronization. In the communication method, when the second secondary synchronization signal is not set for the cell, synchronization is acquired based on the primary synchronization signal and the first secondary synchronization signal, and the second secondary synchronization signal is obtained for the cell. When the setting related to the signal is made, synchronization is acquired based on the first primary synchronization signal and the second secondary synchronization signal, and the plurality of first resource elements to which the second secondary synchronization signal is mapped are the first Different from the plurality of second resource elements to which the secondary synchronization signal is mapped.

  (12) A communication method according to an aspect of the present invention is a communication method used in a base station device that communicates with a terminal device, and includes a primary synchronization signal, a first secondary synchronization signal, and a second secondary synchronization signal. Including the step of transmitting. The communication method transmits the primary synchronization signal and the first secondary synchronization signal to the terminal device when the second secondary synchronization signal is not set for the cell, and the second secondary signal is transmitted to the terminal device for the cell. When the setting relating to the synchronization signal is performed, the primary synchronization signal and the second secondary synchronization signal are transmitted, and the plurality of first resource elements to which the second secondary synchronization signal is mapped include the first secondary synchronization signal. Different from the plurality of second resource elements to be mapped.

  According to the present invention, transmission efficiency can be improved in a wireless communication system in which a base station device and a terminal device communicate.

It is a figure which shows an example of a radio frame structure of the downlink which concerns on this embodiment. It is a figure which shows an example of the radio frame structure of the uplink which concerns on this embodiment. It is the schematic which shows an example of the block configuration of the base station apparatus 2 which concerns on this embodiment It is the schematic which shows an example of the block configuration of the terminal device 1 which concerns on this embodiment. It is a figure which shows an example of the signal structure of the downlink which concerns on this embodiment. It is a figure which shows an example of a structure of the synchronizing signal which concerns on this embodiment. It is a figure which shows an example of a structure of the synchronizing signal which concerns on this embodiment. It is a figure which shows an example of the production | generation formula of the Zadoff-Chu series which concerns on this embodiment. It is a figure which shows an example of numerical formula which determines arrangement | positioning of the synchronizing signal which concerns on this embodiment.

<First Embodiment>
A first embodiment of the present invention will be described below. A base station apparatus (base station, Node B, eNB (eNodeB)) and a terminal apparatus (terminal, mobile station, user apparatus, UE (User equipment)) will be described using a communication system (cellular system) in which communication is performed in a cell. To do.

  The main physical channels and physical signals used in EUTRA and Advanced EUTRA will be described. A channel means a medium used for signal transmission, and a physical channel means a physical medium used for signal transmission. In this embodiment, a physical channel can be used synonymously with a signal. The physical channel may be added in the future, or the structure or format of the physical channel may be changed or added in EUTRA and Advanced EUTRA. However, even if the physical channel is changed or added, the description of this embodiment is not affected.

  In EUTRA and Advanced EUTRA, scheduling of physical channels or physical signals is managed using radio frames. One radio frame is 10 ms, and one radio frame is composed of 10 subframes. Further, one subframe is composed of two slots (that is, one subframe is 1 ms, and one slot is 0.5 ms). Also, resource blocks are used as a minimum scheduling unit in which physical channels are allocated. A resource block is defined by a constant frequency region composed of a set of a plurality of subcarriers (for example, 12 subcarriers) and a region composed of a constant transmission time interval (1 slot) on the frequency axis.

  In EUTRA and Advanced EUTRA, a frame configuration type is defined. Frame structure type 1 can be applied to frequency division duplex (FDD). Frame structure type 2 (Frame structure type 2) can be applied to time division duplex (TDD).

  FIG. 1 is a diagram illustrating an example of a downlink radio frame configuration according to the present embodiment. An OFDM access scheme is used for the downlink. In the downlink, a PDCCH, an EPDCCH, a physical downlink shared channel (PDSCH), and the like are allocated. The downlink radio frame is composed of a downlink resource block (RB) pair. This downlink RB pair is a unit such as downlink radio resource allocation, and is based on a predetermined frequency band (RB bandwidth) and time band (2 slots = 1 subframe). Become. One downlink RB pair is composed of two downlink RBs (RB bandwidth × slot) that are continuous in the time domain. One downlink RB is composed of 12 subcarriers in the frequency domain. Further, in the time domain, it is composed of 7 OFDM symbols when a normal cyclic prefix (CP) is added, and 6 OFDM symbols when a cyclic prefix longer than normal is added. Is done. A region defined by one subcarrier in the frequency domain and one OFDM symbol in the time domain is referred to as a resource element (RE). The physical downlink control channel is a physical channel through which downlink control information such as a terminal device identifier, physical downlink shared channel scheduling information, physical uplink shared channel scheduling information, modulation scheme, coding rate, and retransmission parameter is transmitted. It is. In addition, although the downlink sub-frame in one element carrier (CC; Component Carrier) is described here, a downlink sub-frame is prescribed | regulated for every CC, and a downlink sub-frame is substantially synchronized between CC. .

  In the downlink, a synchronization signal is assigned. The synchronization signal is mainly a downlink signal and / or channel timing between a base station apparatus that transmits a downlink signal and / or channel and a terminal apparatus that receives the downlink signal and / or channel. Used to adjust. Specifically, in the terminal device, the synchronization signal is used to adjust the reception timing of a radio frame, a subframe, or an OFDM symbol. In the terminal device, the synchronization signal is also used for detecting the center frequency of the element carrier. In the terminal device, the synchronization signal is also used for detecting the CP length of the OFDM symbol. In the terminal device, the synchronization signal is also used to identify the cell (base station device) to which the synchronization signal is transmitted. In other words, in the terminal device, the synchronization signal is also used for detecting the cell identifier of the cell to which the synchronization signal is transmitted. In the terminal device, the synchronization signal may also be used for performing AGC (Automatic Gain Control). In the terminal device, the synchronization signal may be used to adjust the processing timing of symbols for performing FFT (Fast Fourier Transform). In the terminal device, the synchronization signal may be used for calculating reference signal received power (RSRP). The synchronization signal may be used for securing a channel through which the synchronization signal is transmitted.

  The primary synchronization signal (first primary synchronization signal) and the secondary synchronization signal (first secondary synchronization signal) are transmitted on the downlink to facilitate cell search. The cell search is a procedure by the terminal device in which the terminal device acquires time and frequency synchronization with the cell and detects the physical cell identifier (physical layer Cell ID) of the cell. E-UTRA cell search supports a flexible overall transmission bandwidth equivalent to 6 resource blocks and more.

A specific example of the arrangement (position, mapping) of the primary synchronization signal and the secondary synchronization signal will be described. FIG. 9 shows formulas for determining subcarriers and OFDM symbols on which synchronization signals are arranged. If k is defined as an index for designating a resource element in the frequency domain and l in the time domain, the primary synchronization signal and the secondary synchronization signal are expressed by Equation (0-a), Equation (1-a), and Equation (2) in FIG. ). Here, N _RB ^DL is the number of resource blocks specified from the downlink bandwidth setting information, N _sc ^RB is the resource block size in the frequency domain, the number of subcarriers per resource block, and N _symb ^DL is the downlink The number of OFDM symbols per slot. Here, a _{k, l} is a symbol in the resource element (k, l), d is a sequence, and n takes a value from 0 to 2N _M -1. Further, mod is a function representing the remainder, and AmodB represents the remainder when A is divided by B. In addition, here, the primary synchronization signals and secondary synchronization signals, N _M is 31. Here, h is 1 in the primary synchronization signal and the secondary synchronization signal.

  The primary synchronization signal (Primary Synchronization Signal, PSS) and the secondary synchronization signal (Secondary Synchronization Signal, SSS) shown in FIG. 1 do not depend on the downlink bandwidth (downlink system bandwidth, downlink transmission bandwidth). And 62 subcarriers (62 resource elements) centered on the center frequency. Note that a DC subcarrier (DC subcarrier) corresponding to the center of subcarriers in the system bandwidth is not used as a primary synchronization signal and a secondary synchronization signal. Note that 5 subcarriers (5 resource elements) at both ends of the primary synchronization signal and the secondary synchronization signal are reserved and are not used for transmission of the primary synchronization signal and the secondary synchronization signal. In addition to the 62 resource elements used for the transmission described above, the 5 resource elements at both ends are also referred to as a primary synchronization signal and a secondary synchronization signal.

The primary synchronization signal is generated based on a Zadoff-Chu sequence (ZC sequence) in the frequency domain. The Zadoff-Chu sequence is generated by the equation (a) in FIG. 8, and in particular, the primary synchronization signal is generated by using the equation (b) in FIG. Here, _NZC is the sequence length of the Zadoff-Chu sequence, and u is the root index (Zadoff-Chu root sequence index). The primary synchronization signal is generated based on three types of route indexes. The root index is associated with three unique identifiers derived from cell identifiers (cell ID, physical layer cell identifier, physical-layer cell identity). The primary synchronization signal is located in the last OFDM symbol of slot 0 (ie, the first slot of subframe 0) and slot 10 (ie, the first slot of subframe 5) in frame configuration type 1. The primary synchronization signal is located in the third OFDM symbol of the first slot of subframes 1 and 6 in frame configuration type type 2.

  The secondary synchronization signal is defined by a combination of two 31-length sequences. The sequence used for the secondary synchronization signal is a sequence in which two sequences of length 31 are alternately arranged. The concatenated sequence is scrambled by a scramble sequence given by the primary synchronization signal. The sequence of length 31 is generated based on the M sequence. The length 31 sequence is generated based on 168 unique physical layer cell identifier groups derived from the cell identifiers. The scramble sequence given by the primary synchronization signal is an M sequence generated based on three unique identifiers. The mapping of the secondary synchronization signal sequence to the resource element depends on the frame configuration. The secondary synchronization signal is located in the second OFDM symbol from the end of slot 0 (ie, the first slot of subframe 0) and slot 10 (ie, the first slot of subframe 5) in frame configuration type 1. Is done. The secondary synchronization signal is located in the last OFDM symbol of slot 1 (ie, the second slot of subframe 0) and slot 11 (ie, the second slot of subframe 5) in frame configuration type 2.

  Although not shown here, a physical broadcast information channel or a downlink reference signal (RS: Reference Signal, downlink reference signal) may be arranged in the downlink subframe. As a downlink reference signal, a cell-specific reference signal (CRS: Cell-specific RS) transmitted on the same transmission port as the PDCCH, and a channel state information reference signal (CSI: Channel State Information) used for measurement of channel state information (CSI) CSI-RS, non-zero power CSI-RS, NZP CSI-RS), terminal-specific reference signal (URS: UE-specific RS) transmitted on the same transmission port as some PDSCH, transmitted on the same transmission port as EPDCCH Demodulation reference signals (DMRS: Demodulation RS). Moreover, the carrier in which CRS is not arrange | positioned may be sufficient. At this time, in some subframes (for example, the first and sixth subframes in a radio frame), as a time and / or frequency tracking signal, a part of CRS transmission ports (for example, transmission port 0 only) ) Or signals similar to those corresponding to all transmission ports (referred to as extended synchronization signals) can be inserted. In addition, a terminal-specific reference signal transmitted through the same transmission port as a part of PDSCH is also referred to as a terminal-specific reference signal or DMRS associated with the PDSCH. The demodulation reference signal transmitted at the same transmission port as the EPDCCH is also referred to as DMRS associated with the EPDCCH.

  Although not shown here, the downlink subframe mainly includes zero power CSI-RS (ZP CSI-RS) used mainly for rate matching of PDSCH transmitted at the same time, mainly channel state information. CSI interference management (CSI-IM) used for the interference measurement may be arranged. Zero power CSI-RS and CSI-IM may be arrange | positioned at the resource element which can arrange | position non-zero power CSI-RS. CSI-IM may be set over zero power CSI-RS.

Although not shown here, a detection signal (DS: Discovery Signal) may be arranged in the downlink subframe. In a certain cell, DS (DS Occlusion) is configured by a time period (DS period) of a predetermined number of consecutive subframes. The predetermined number is 1 to 5 in FDD (Frame structure type 1) and 2 to 5 in TDD (Frame structure type 2). The predetermined number is set by RRC signaling. The terminal device is set with a section for measuring the DS period. The setting of the section for measuring the DS period is also referred to as DMTC (Discovery signals measurement timing configuration). A section in which the terminal apparatus measures the DS period (DMTC section, DMTC Occasion) is set in a section of 6 ms (6 subframes). The terminal assumes that the DS is transmitted (mapped and generated) for each subframe set by the parameter dmtc-Periodicity set by RRC signaling. In the downlink subframe, the terminal assumes the presence of a DS configured to include the following signals.
(1) CRS of antenna port 0 in DwPTS of all downlink subframes and all special subframes in the DS period.
(2) In FDD, PSS in the first subframe of the DS period. In TDD, PSS in the second subframe of the DS period.
(3) SSS in the first subframe of the DS period.
(4) Non-zero power CSI-RS in zero or more subframes of the DS period. The non-zero power CSI-RS is set by RRC signaling.

  The terminal performs measurement based on the set DS. The measurement is performed using CRS in DS or non-zero power CSI-RS in DS. Moreover, in the setting regarding DS, a plurality of non-zero power CSI-RSs can be set.

  FIG. 2 is a diagram illustrating an example of an uplink radio frame configuration according to the present embodiment. The SC-FDMA scheme is used for the uplink. In the uplink, a physical uplink shared channel (PUSCH), PUCCH, and the like are allocated. Further, an uplink reference signal (uplink reference signal) is assigned to a part of PUSCH or PUCCH. The uplink radio frame is composed of uplink RB pairs. This uplink RB pair is a unit for allocation of uplink radio resources and the like, and is based on a predetermined frequency band (RB bandwidth) and time band (2 slots = 1 subframe). Become. One uplink RB pair is composed of two uplink RBs (RB bandwidth × slot) that are continuous in the time domain. One uplink RB is composed of 12 subcarriers in the frequency domain. In the time domain, it is composed of 7 SC-FDMA symbols when a normal cyclic prefix is added, and 6 when a cyclic prefix longer than normal is added. Here, although an uplink subframe in one CC is described, an uplink subframe is defined for each CC.

  The synchronization signal is composed of three kinds of primary synchronization signals and secondary synchronization signals composed of 31 kinds of codes arranged alternately in the frequency domain. 504 cell identifiers (physical cell identity (PCI)) for identifying the station device and frame timing for radio synchronization are shown. The terminal device specifies the physical cell ID of the synchronization signal received by the cell search.

  A physical broadcast information channel (PBCH; Physical Broadcast Channel) is transmitted for the purpose of notifying (setting) control parameters (broadcast information (system information); System information) that are commonly used in terminal devices in the cell. Radio resources for transmitting broadcast information on the physical downlink control channel are notified to terminal devices in the cell, and broadcast information not notified on the physical broadcast information channel is transmitted by the physical downlink shared channel in the notified radio resources. A layer 3 message (system information) for notifying broadcast information is transmitted.

  As broadcast information, a cell global identifier (CGI) indicating a cell-specific identifier, a tracking area identifier (TAI) for managing a standby area by paging, random access setting information (transmission timing timer, etc.), Common radio resource setting information, neighboring cell information, uplink access restriction information, etc. in the cell are notified.

  The downlink reference signal is classified into a plurality of types according to its use. For example, cell-specific reference signals (RS) are pilot signals transmitted at a predetermined power for each cell, and are downlink reference signals that are periodically repeated in the frequency domain and the time domain based on a predetermined rule. It is. The terminal device measures the reception quality for each cell by receiving the cell-specific RS. The terminal apparatus also uses the cell-specific RS as a reference signal for demodulating the physical downlink control channel or the physical downlink shared channel transmitted simultaneously with the cell-specific RS. As a sequence used for the cell-specific RS, a sequence that can be identified for each cell is used.

  The downlink reference signal is also used for estimation of downlink propagation path fluctuations. A downlink reference signal used for estimation of propagation path fluctuation is referred to as a channel state information reference signal (CSI-RS). Also, the downlink reference signal set individually for the terminal device is referred to as UE specific reference signals (URS), Demodulation Reference Signal (DMRS) or Dedicated RS (DRS), or an extended physical downlink control channel, or Referenced for channel propagation path compensation processing when demodulating a physical downlink shared channel.

  A physical downlink control channel (PDCCH; Physical Downlink Control Channel) is transmitted by several OFDM symbols (for example, 1 to 4 OFDM symbols) from the head of each subframe. An enhanced physical downlink control channel (EPDCCH) is a physical downlink control channel arranged in an OFDM symbol in which the physical downlink shared channel PDSCH is arranged. The PDCCH or EPDCCH is used for the purpose of notifying the terminal device of radio resource allocation information according to the scheduling of the base station device and information for instructing an adjustment amount of increase / decrease of transmission power. Hereinafter, when simply referred to as a physical downlink control channel (PDCCH), it means both physical channels of PDCCH and EPDCCH unless otherwise specified.

  The terminal device monitors (monitors) the physical downlink control channel addressed to itself before transmitting / receiving the downlink data and the layer 2 message and the layer 3 message (paging, handover command, etc.) that are the upper layer control information. By receiving the physical downlink control channel addressed to its own device, it is necessary to acquire radio resource allocation information called an uplink grant at the time of transmission and a downlink grant (downlink assignment) at the time of reception from the physical downlink control channel. is there. In addition, the physical downlink control channel may be configured to be transmitted in the area of the resource block that is assigned individually (dedicated) from the base station apparatus to the terminal apparatus, in addition to being transmitted by the OFDM symbol described above. Is possible.

  The physical uplink control channel (PUCCH; Physical Uplink Control Channel) is a downlink data reception acknowledgment (HARQ-ACK; Hybrid Automatic Repeat request-AcknowledgmentNackAckNegation or ACK / NACK); It is used to perform Acknowledgment), downlink propagation path (channel state) information (CSI; Channel State Information), and uplink radio resource allocation request (radio resource request, scheduling request (SR)).

  The CSI includes a reception quality index (CQI: Channel Quality Indicator), a precoding matrix index (PMI), a precoding type index (PTI), and a rank index (CRI) corresponding to the CSI. And can be used to specify (represent) a suitable modulation scheme and coding rate, a suitable precoding matrix, a suitable PMI type, and a suitable rank, respectively. Each Indicator may be written as Indication. Also, for CQI and PMI, wideband CQI and PMI assuming transmission using all resource blocks in one cell and some continuous resource blocks (subbands) in one cell were used. It is classified into subband CQI and PMI assuming transmission. In addition to the normal type of PMI that represents one suitable precoding matrix with one PMI, the PMI represents one suitable precoding matrix using two types of PMIs, the first PMI and the second PMI. There is a type of PMI.

  For example, the terminal apparatus 1 occupies a group of downlink physical resource blocks, and the error probability of one PDSCH transport determined by a combination of a modulation scheme and a transport block size corresponding to the CQI index has a predetermined value (for example, , 0.1), the CQI index that satisfies the condition is not reported.

  In addition, the downlink physical resource block used for CQI, PMI, and / or RI calculation is referred to as a CSI reference resource (CSI reference resource).

  The terminal device 1 reports CSI to the base station device 2. The CSI report includes a periodic CSI report and an aperiodic CSI report. In periodic CSI reporting, the terminal device 1 reports CSI at the timing set in the higher layer. In the aperiodic CSI report, the terminal device 1 reports the CSI at a timing based on the information of the CSI request included in the received uplink DCI format (uplink grant) or random access response grant.

  The terminal device 1 reports CQI and / or PMI and / or RI. Note that the terminal apparatus 1 may not report PMI and / or RI depending on the setting of the upper layer. The settings of the upper layer are, for example, a transmission mode, a feedback mode, a report type, and a parameter indicating whether to report PMI / RI.

  In the terminal device 1, one or a plurality of CSI processes (CSI processes) may be set for one serving cell. The CSI process is set in association with the CSI report. One CSI process is associated with one CSI-RS resource and one CSI-IM resource.

  The physical downlink shared channel (PDSCH; Physical Downlink Shared Channel) is not only downlink data, but also response to random access (random access response, RAR), paging, and broadcast information (system information) not notified by the physical broadcast information channel. It is also used to notify the terminal device as a layer 3 message. The radio resource allocation information of the physical downlink shared channel is indicated by the physical downlink control channel. The physical downlink shared channel is transmitted after being arranged in an OFDM symbol other than the OFDM symbol through which the physical downlink control channel is transmitted. That is, the physical downlink shared channel and the physical downlink control channel are time division multiplexed within one subframe.

  A physical uplink shared channel (PUSCH) mainly transmits uplink data and uplink control information, and can also include uplink control information such as CSI and ACK / NACK. In addition to uplink data, it is also used to notify the base station apparatus of layer 2 messages and layer 3 messages, which are higher layer control information. Similarly to the downlink, the radio resource allocation information of the physical uplink shared channel is indicated by the physical downlink control channel.

  The uplink reference signal (uplink reference signal; Uplink Reference Signal, uplink pilot signal, also referred to as uplink pilot channel) is transmitted from the base station apparatus to the physical uplink control channel PUCCH and / or the physical uplink shared channel PUSCH. A demodulation reference signal (DMRS) used for demodulation and a sounding reference signal (SRS) used mainly by the base station apparatus to estimate an uplink channel state are included. It is. The sounding reference signal includes a periodic sounding reference signal (Periodic SRS) transmitted periodically and an aperiodic sounding reference signal (Aperiodic SRS) transmitted when instructed by the base station apparatus. .

  A physical random access channel (PRACH) is a channel used to notify (set) a preamble sequence and has a guard time. The preamble sequence is configured to notify information to the base station apparatus by a plurality of sequences. For example, when 64 types of sequences are prepared, 6-bit information can be indicated to the base station apparatus. The physical random access channel is used as an access means for the terminal device to the base station device.

  The terminal apparatus transmits transmission timing adjustment information (timing required for an uplink radio resource request when the physical uplink control channel is not set for the SR, or for matching the uplink transmission timing with the reception timing window of the base station apparatus. The physical random access channel is used to request the base station apparatus for an advance (also called a timing advance (TA) command). Also, the base station apparatus can request the terminal apparatus to start a random access procedure using the physical downlink control channel.

  The random access response is response information from the base station apparatus with respect to the random access of the terminal apparatus. The random access response is included in the PDSCH scheduled by the control information of the PDCCH having the CRC scrambled by the RA-RNTI, and is transmitted from the base station apparatus. The random access response includes transmission timing adjustment information, an uplink grant (the uplink grant included in the random access response is also referred to as a random access response grant), and Temporary C-RNTI information that is a temporary terminal device identifier. include.

  The layer 3 message is a message handled by a control plane (CP (Control-plane, C-Plane)) protocol exchanged between the terminal device and the RRC (Radio Resource Control) layer between the base station device and the RRC signaling or RRC. Can be used interchangeably with message. A protocol that handles user data (uplink data and downlink data) with respect to the control plane is referred to as a user plane (UP (User-plane, U-Plane)). Here, the transport block which is transmission data in the physical layer includes a C-Plane message and U-Plane data in the upper layer. Detailed descriptions of other physical channels are omitted.

  The communicable range (communication area) of each frequency controlled by the base station apparatus is regarded as a cell. At this time, the communication area covered by the base station apparatus may have a different width and a different shape for each frequency. Moreover, the area to cover may differ for every frequency. A wireless network in which cells having different types of base station apparatuses and different cell radii are mixed in the same frequency and / or different frequency areas to form one communication system is referred to as a heterogeneous network. .

  The terminal device operates by regarding the inside of the cell as a communication area. When a terminal device moves from one cell to another cell, it moves to another appropriate cell by a cell reselection procedure during non-wireless connection (during non-communication) and by a handover procedure during wireless connection (during communication). To do. An appropriate cell is a cell that is generally determined that access by a terminal device is not prohibited based on information specified by a base station device, and the downlink reception quality satisfies a predetermined condition. Indicates the cell to be used.

  Also, the terminal device and the base station device aggregate (aggregate) frequencies (component carriers or frequency bands) of a plurality of different frequency bands (frequency bands) by carrier aggregation into one frequency (frequency band). You may apply the technique handled like. Component carriers include uplink component carriers corresponding to the uplink and downlink component carriers corresponding to the downlink. In this specification, a frequency and a frequency band may be used synonymously.

  For example, when five component carriers having a frequency bandwidth of 20 MHz are aggregated by carrier aggregation, a terminal device capable of carrier aggregation regards these as a frequency bandwidth of 100 MHz and performs transmission / reception. The component carriers to be aggregated may be continuous frequencies, or may be frequencies at which all or part of them are discontinuous. For example, when the usable frequency band is 800 MHz band, 2 GHz band, and 3.5 GHz band, one component carrier is transmitted in the 800 MHz band, another component carrier is transmitted in the 2 GHz band, and another component carrier is transmitted in the 3.5 GHz band. It may be.

  It is also possible to aggregate a plurality of continuous or discontinuous component carriers in the same frequency band. The frequency bandwidth of each component carrier may be a frequency bandwidth (for example, 5 MHz or 10 MHz) narrower than the receivable frequency bandwidth (for example, 20 MHz) of the terminal device, and the aggregated frequency bandwidth may be different from each other. . The frequency bandwidth is preferably equal to one of the frequency bandwidths of the conventional cell in consideration of backward compatibility, but may be a frequency bandwidth different from that of the conventional cell.

  In addition, component carriers (carrier types) that are not backward compatible may be aggregated. Note that the number of uplink component carriers assigned (set or added) to the terminal device by the base station device is preferably equal to or less than the number of downlink component carriers.

  A cell composed of an uplink component carrier in which an uplink control channel is set for a radio resource request and a downlink component carrier that is cell-specifically connected to the uplink component carrier is a primary cell (PCell: Primary cell). ). Moreover, the cell comprised from component carriers other than a primary cell is called a secondary cell (SCell: Secondary cell). The terminal device performs reception of a paging message in the primary cell, detection of update of broadcast information, initial access procedure, setting of security information, and the like, but may not perform these in the secondary cell.

  The primary cell is not subject to activation and deactivation control (that is, it is always considered to be activated), but the secondary cell is in a state of activation and deactivation. In addition to being explicitly specified by the base station apparatus, the state is changed based on a timer set in the terminal apparatus for each component carrier. The primary cell and the secondary cell are collectively referred to as a serving cell.

  Note that carrier aggregation is communication performed by a plurality of cells using a plurality of component carriers (frequency bands), and is also referred to as cell aggregation. The terminal device may be wirelessly connected to the base station device via a relay station device (or repeater) for each frequency. That is, the base station apparatus of this embodiment can be replaced with a relay station apparatus.

  The base station apparatus manages a cell, which is an area in which the terminal apparatus can communicate with the base station apparatus, for each frequency. One base station apparatus may manage a plurality of cells. The cells are classified into a plurality of types according to the size (cell size) of the area communicable with the terminal device. For example, the cell is classified into a macro cell and a small cell. Further, small cells are classified into femtocells, picocells, and nanocells according to the size of the area. When a terminal device can communicate with a certain base station device, a cell that is set to be used for communication with the terminal device among the cells of the base station device is a serving cell. A cell that is not used for other communication is referred to as a neighbor cell.

  In other words, in carrier aggregation (also referred to as carrier aggregation), the set serving cells include one primary cell and one or more secondary cells.

  The primary cell is a serving cell in which an initial connection establishment procedure has been performed, a serving cell that has started a connection reconfiguration procedure, or a cell designated as a primary cell in a handover procedure. The primary cell operates at the primary frequency. The secondary cell may be set at the time when the connection is (re-) built or after that. The secondary cell operates at the secondary frequency. The connection may be referred to as an RRC connection. For a terminal device supporting CA, aggregation is performed by one primary cell and one or more secondary cells.

  In this embodiment, LAA (Licensed Assisted Access) is used. In LAA, an assigned frequency is set (used) in the primary cell, and an unassigned frequency is set in at least one of the secondary cells. A secondary cell in which an unassigned frequency is set is assisted from a primary cell or a secondary cell in which an assigned frequency is set. For example, a primary cell or a secondary cell in which an assigned frequency is set is set and / or controlled by a RRC signaling, a MAC signaling, and / or a PDCCH signaling with respect to a secondary cell in which an unassigned frequency is set. Notification of. In the present embodiment, a cell assisted from a primary cell or a secondary cell is also referred to as an LAA cell. LAA cells can be aggregated (assisted) by carrier aggregation with a primary cell and / or a secondary cell. The primary cell or secondary cell that assists the LAA cell is also referred to as an assist cell.

  The LAA cells may be aggregated (assisted) by dual connectivity with primary cells and / or secondary cells.

  In the following, the basic structure (architecture) of dual connectivity will be described. For example, the case where the terminal device 1 is simultaneously connected to a plurality of base station devices 2 (for example, the base station device 2-1 and the base station device 2-2) will be described. The base station apparatus 2-1 is a base station apparatus that constitutes a macro cell, and the base station apparatus 2-2 is a base station apparatus that constitutes a small cell. As described above, the simultaneous connection using the plurality of cells belonging to the plurality of base station apparatuses 2 by the terminal apparatus 1 is referred to as dual connectivity. The cells belonging to each base station apparatus 2 may be operated at the same frequency or may be operated at different frequencies.

  Note that carrier aggregation is different from dual connectivity in that a plurality of cells are managed by one base station apparatus 2 and the frequency of each cell is different. In other words, carrier aggregation is a technique for connecting one terminal apparatus 1 and one base station apparatus 2 via a plurality of cells having different frequencies, whereas dual connectivity is one terminal apparatus 1. And a plurality of base station apparatuses 2 via a plurality of cells having the same or different frequencies.

  The terminal device 1 and the base station device 2 can apply a technique applied to carrier aggregation to dual connectivity. For example, the terminal device 1 and the base station device 2 may apply techniques such as primary cell and secondary cell allocation, activation / deactivation, and the like to cells connected by dual connectivity.

  In the dual connectivity, the base station device 2-1 or the base station device 2-2 is connected to the MME, the SGW, and the backbone line. The MME is a higher-level control station apparatus corresponding to MME (Mobility Management Entity), and plays a role of setting mobility of the terminal apparatus 1 and authentication control (security control) and a route of user data to the base station apparatus 2. Have. The SGW is a higher-level control station device corresponding to Serving Gateway (S-GW), and has a role of transmitting user data according to a user data path to the terminal device 1 set by the MME.

  In dual connectivity, the connection path between the base station apparatus 2-1 or the base station apparatus 2-2 and the SGW is referred to as an SGW interface. In addition, the connection path between the base station device 2-1 or the base station device 2-2 and the MME is referred to as an MME interface. The connection path between the base station apparatus 2-1 and the base station apparatus 2-2 is called a base station interface. The SGW interface is also referred to as an S1-U interface in EUTRA. The MME interface is also referred to as an S1-MME interface in EUTRA. The base station interface is also referred to as an X2 interface in EUTRA.

  An example of an architecture that realizes dual connectivity will be described. In dual connectivity, the base station apparatus 2-1 and the MME are connected by an MME interface. Moreover, the base station apparatus 2-1 and SGW are connected by the SGW interface. Further, the base station device 2-1 provides a communication path with the MME and / or the SGW to the base station device 2-2 via the base station interface. In other words, the base station device 2-2 is connected to the MME and / or the SGW via the base station device 2-1.

  Another example of another architecture for realizing dual connectivity will be described. In dual connectivity, the base station apparatus 2-1 and the MME are connected by an MME interface. Moreover, the base station apparatus 2-1 and SGW are connected by the SGW interface. The base station device 2-1 provides a communication path with the MME to the base station device 2-2 via the base station interface. In other words, the base station apparatus 2-2 is connected to the MME via the base station apparatus 2-1. Further, the base station apparatus 2-2 is connected to the SGW via the SGW interface.

  The base station device 2-2 and the MME may be directly connected by the MME interface.

  From another viewpoint, dual connectivity refers to radio resources provided from at least two different network points (a master base station device (MeNB: Master eNB) and a secondary base station device (SeNB: Secondary eNB)). This is an operation consumed by the terminal device. In other words, dual connectivity is that a terminal device makes an RRC connection at at least two network points. In the dual connectivity, the terminal devices may be connected in a RRC connection (RRC_CONNECTED) state and by a non-ideal backhaul.

  In dual connectivity, a base station apparatus connected to at least the S1-MME and serving as a mobility anchor for the core network is referred to as a master base station apparatus. A base station device that is not a master base station device that provides additional radio resources to the terminal device is referred to as a secondary base station device. When a serving cell group associated with the master base station apparatus is referred to as a master cell group (MCG), and a serving cell group associated with the secondary base station apparatus is referred to as a secondary cell group (SCG). There is also. The cell group may be a serving cell group.

  In dual connectivity, the primary cell belongs to the MCG. In the SCG, a secondary cell corresponding to the primary cell is referred to as a primary secondary cell (pSCell: Primary Secondary Cell). Note that the pSCell may be referred to as a special cell or a special secondary cell (Special SCell). The special SCell (base station apparatus configuring the special SCell) may support a part of the function of the PCell (base station apparatus configuring the PCell) (for example, a function of transmitting and receiving PUCCH). Moreover, only some functions of PCell may be supported by pSCell. For example, the pSCell may support a function of transmitting PDCCH. Further, the pSCell may support a function of performing PDCCH transmission using a search space different from CSS (common search space) or USS (UE dedicated search space). For example, a search space different from USS is based on a search space determined based on a value defined in the specification, a search space determined based on an RNTI different from C-RNTI, and a value set in an upper layer different from RNTI. Search space determined by Further, the pSCell may always be in an activated state. Moreover, pSCell is a cell which can receive PUCCH.

  In dual connectivity, a data radio bearer (DRB: Date Radio Bearer) may be individually allocated in the MeNB and SeNB. On the other hand, a signaling radio bearer (SRB) may be allocated only to the MeNB. In dual connectivity, duplex modes may be set individually for MCG and SCG or PCell and pSCell, respectively. In dual connectivity, MCG and SCG or PCell and pSCell may not be synchronized. In the dual connectivity, a plurality of timing adjustment parameters (TAGs) may be set in each of the MCG and the SCG. That is, the terminal device can perform uplink transmission at different timings in each CG.

  In the dual connectivity, the terminal apparatus can transmit the UCI corresponding to the cell in the MCG only to the MeNB (PCell), and the UCI corresponding to the cell in the SCG can be transmitted only to the SeNB (pSCell). For example, UCI is SR, HARQ-ACK, and / or CSI. Further, in each UCI transmission, a transmission method using PUCCH and / or PUSCH is applied to each cell group.

  All signals can be transmitted and received in the primary cell, but there are signals that cannot be transmitted and received in the secondary cell. For example, PUCCH (Physical Uplink Control Channel) is transmitted only in the primary cell. Also, PRACH (Physical Random Access Channel) is transmitted only in the primary cell unless a plurality of TAGs (Timing Advance Groups) are set between cells. PBCH (Physical Broadcast Channel) is transmitted only in the primary cell. Also, a MIB (Master Information Block) is transmitted only in the primary cell. In the primary secondary cell, signals that can be transmitted and received in the primary cell are transmitted and received. For example, PUCCH may be transmitted in the primary secondary cell. Moreover, PRACH may be transmitted by a primary secondary cell irrespective of whether several TAG is set. Moreover, PBCH and MIB may be transmitted in the primary secondary cell.

  In the primary cell, RLF (Radio Link Failure) is detected. The secondary cell does not recognize that the RLF is detected even if the condition for detecting the RLF is satisfied. In the primary secondary cell, the RLF is detected if the condition is satisfied. When the RLF is detected in the primary secondary cell, the upper layer of the primary secondary cell notifies the upper layer of the primary cell that the RLF has been detected. In the primary cell, SPS (Semi-Persistent Scheduling) or DRX (Distinuous Reception) may be performed. The secondary cell may perform the same DRX as the primary cell. In the secondary cell, information / parameters related to MAC settings are basically shared with the primary cell / primary secondary cell of the same cell group. Some parameters (for example, sTAG-Id) may be set for each secondary cell. Some timers and counters may be applied only to the primary cell and / or the primary secondary cell. A timer or a counter that is applied only to the secondary cell may be set.

  In an example in which dual connectivity is applied to an LAA cell, the MCG (base station apparatus 2-1) is a base station apparatus constituting a primary cell, and the SCG (base station apparatus 2-2) constitutes an LAA cell. It is a base station device. That is, the LAA cell is set as a pSCell of SCG.

  In another example in which dual connectivity is applied to the LAA cell, the MCG is a base station apparatus constituting a primary cell, and the SCG is a base station apparatus constituting a pSCell and an LAA cell. That is, the LAA cell is assisted from the pSCell in the SCG. When a secondary cell is further set in the SCG, the LAA cell may be assisted from the secondary cell.

  In another example when dual connectivity is applied to the LAA cell, the MCG is a base station apparatus that constitutes the primary cell and the LAA cell, and the SCG is a base station apparatus that constitutes the pSCell. That is, the LAA cell is assisted from the primary cell in the MCG. When a secondary cell is further set in the MCG, the LAA cell may be assisted from the secondary cell.

  FIG. 3 is a schematic diagram illustrating an example of a block configuration of the base station apparatus 2 according to the present embodiment. The base station apparatus 2 includes an upper layer (upper layer control information notification unit, upper layer processing unit) 501, a control unit (base station control unit) 502, a codeword generation unit 503, a downlink subframe generation unit 504, and an OFDM signal transmission. Unit (downlink transmission unit) 506, transmission antenna (base station transmission antenna) 507, reception antenna (base station reception antenna) 508, SC-FDMA signal reception unit (CSI reception unit) 509, uplink subframe processing unit 510 Have. The downlink subframe generation unit 504 includes a downlink reference signal generation unit 505. Further, the uplink subframe processing unit 510 includes an uplink control information extraction unit (CSI acquisition unit) 511.

  FIG. 4 is a schematic diagram illustrating an example of a block configuration of the terminal device 1 according to the present embodiment. The terminal device 1 includes a reception antenna (terminal reception antenna) 601, an OFDM signal reception unit (downlink reception unit) 602, a downlink subframe processing unit 603, a transport block extraction unit (data extraction unit) 605, a control unit (terminal) Control unit) 606, upper layer (upper layer control information acquisition unit, upper layer processing unit) 607, channel state measurement unit (CSI generation unit) 608, uplink subframe generation unit 609, SC-FDMA signal transmission unit (UCI transmission) Part) 611 and 612 and transmission antennas (terminal transmission antennas) 613 and 614. The downlink subframe processing unit 603 includes a downlink reference signal extraction unit 604. Also, the uplink subframe generation unit 609 includes an uplink control information generation unit (UCI generation unit) 610.

  First, the flow of downlink data transmission / reception will be described using FIG. 3 and FIG. In the base station apparatus 2, the control unit 502 includes MCS (Modulation and Coding Scheme) indicating a downlink modulation scheme and coding rate, downlink resource allocation indicating an RB used for data transmission, and information used for HARQ control ( Redundancy version, HARQ process number, and new data index) are stored, and the codeword generation unit 503 and the downlink subframe generation unit 504 are controlled based on these. Downlink data (also referred to as a downlink transport block) sent from the upper layer 501 is subjected to processing such as error correction coding and rate matching processing in the codeword generation unit 503 under the control of the control unit 502. And a codeword is generated. A maximum of two codewords are transmitted simultaneously in one subframe in one cell. The downlink subframe generation unit 504 generates a downlink subframe according to an instruction from the control unit 502. First, the codeword generated by the codeword generation unit 503 is converted into a modulation symbol sequence by a modulation process such as PSK (Phase Shift Keying) modulation or QAM (Quadrature Amplitude Modulation) modulation. Also, the modulation symbol sequence is mapped to REs in some RBs, and a downlink subframe for each antenna port is generated by precoding processing. At this time, the transmission data sequence transmitted from the higher layer 501 includes higher layer control information that is control information (for example, dedicated (individual) RRC (Radio Resource Control) signaling) in the higher layer. Also, the downlink reference signal generation section 505 generates a downlink reference signal. The downlink subframe generation unit 503 maps the downlink reference signal to the RE in the downlink subframe according to an instruction from the control unit 502. The downlink subframe generated by the downlink subframe generation unit 504 is modulated into an OFDM signal by the OFDM signal transmission unit 506 and transmitted via the transmission antenna 507. Here, a configuration having one OFDM signal transmission unit 506 and one transmission antenna 507 is illustrated here, but when transmitting a downlink subframe using a plurality of antenna ports, transmission is performed with the OFDM signal transmission unit 506. A configuration including a plurality of antennas 507 may be employed. Further, the downlink subframe generation unit 504 can also have a capability of generating a physical layer downlink control channel such as PDCCH or EPDCCH and mapping it to the RE in the downlink subframe. A plurality of base station apparatuses (base station apparatus 2-1 and base station apparatus 2-2) each transmit an individual downlink subframe.

  In the terminal device 1, the OFDM signal is received by the OFDM signal receiving unit 602 via the receiving antenna 601, and subjected to OFDM demodulation processing. The downlink subframe processing unit 603 first detects a physical layer downlink control channel such as PDCCH or EPDCCH. More specifically, the downlink subframe processing unit 603 decodes the PDCCH or EPDCCH as transmitted in an area where the PDCCH or EPDCCH can be allocated, and confirms a CRC (Cyclic Redundancy Check) bit added in advance. (Blind decoding) That is, the downlink subframe processing unit 603 monitors PDCCH and EPDCCH. One CRC bit is assigned to one terminal such as an ID (C-RNTI (Cell-Radio Network Temporary Identifier) or SPS-C-RNTI (Semi Persistent Scheduling-C-RNTI)) assigned in advance from the base station apparatus. If it matches the terminal unique identifier or Temporary C-RNTI), the downlink subframe processing unit 603 recognizes that the PDCCH or EPDCCH has been detected, and uses the control information included in the detected PDCCH or EPDCCH to perform PDSCH. Take out. The control unit 606 holds MCS indicating the modulation scheme and coding rate in the downlink based on the control information, downlink resource allocation indicating the RB used for downlink data transmission, and information used for HARQ control, based on these And controls the downlink subframe processing unit 603, the transport block extraction unit 605, and the like. More specifically, the control unit 606 performs control so as to perform RE demapping processing and demodulation processing corresponding to the RE mapping processing and modulation processing in the downlink subframe generation unit 504. The PDSCH extracted from the received downlink subframe is sent to the transport block extraction unit 605. Also, the downlink reference signal extraction unit 604 in the downlink subframe processing unit 603 extracts a downlink reference signal from the downlink subframe. The transport block extraction unit 605 performs rate matching processing in the codeword generation unit 503, rate matching processing corresponding to error correction coding, error correction decoding, and the like, extracts transport blocks, and sends them to the upper layer 607. It is done. The transport block includes upper layer control information, and the upper layer 607 informs the control unit 606 of necessary physical layer parameters based on the upper layer control information. The plurality of base station apparatuses 2 (base station apparatus 2-1 and base station apparatus 2-2) transmit individual downlink subframes, and the terminal apparatus 1 receives them, so that The processing may be performed for each downlink subframe for each of the plurality of base station apparatuses 2. At this time, the terminal device 1 may or may not recognize that a plurality of downlink subframes are transmitted from the plurality of base station devices 2. When not recognizing, the terminal device 1 may simply recognize that a plurality of downlink subframes are transmitted in a plurality of cells. Further, the transport block extraction unit 605 determines whether or not the transport block has been correctly detected, and the determination result is sent to the control unit 606.

  Next, the flow of uplink signal transmission / reception will be described. In the terminal apparatus 1, the downlink reference signal extracted by the downlink reference signal extraction unit 604 is sent to the channel state measurement unit 608 under the instruction of the control unit 606, and the channel state measurement unit 608 performs channel state and / or interference. And CSI is calculated based on the measured channel conditions and / or interference. Also, the control unit 606 sends the HARQ-ACK (DTX (untransmitted), ACK (successful detection), or NACK ( Detection failure)) and mapping to downlink subframes. The terminal device 1 performs these processes on the downlink subframes for each of a plurality of cells. In uplink control information generation section 610, PUCCH including the calculated CSI and / or HARQ-ACK is generated. In the uplink subframe generation unit 609, the PUSCH including the uplink data sent from the higher layer 607 and the PUCCH generated in the uplink control information generation unit 610 are mapped to the RB in the uplink subframe, and the uplink A subframe is generated. The uplink subframe is subjected to SC-FDMA modulation in the SC-FDMA signal transmission unit 611 to generate an SC-FDMA signal, and is transmitted via the transmission antenna 613.

  Here, the terminal device 1 performs (derived) a channel measurement for calculating a CQI value based on CRS or CSI-RS (non-zero power CSI-RS). Whether the terminal device 1 derives based on CRS or CSI-RS is switched by an upper layer signal. Specifically, in the transmission mode in which CSI-RS is set, channel measurement for calculating CQI is derived based only on CSI-RS. Specifically, in a transmission mode in which CSI-RS is not set, channel measurement for calculating CQI is derived based on CRS. An RS used in channel measurement for calculating CSI is also referred to as a first RS.

  Here, when the terminal apparatus 1 is set in the higher layer, the terminal apparatus 1 performs (derived) interference measurement for calculating the CQI based on the CSI-IM or the second RS. Specifically, in a transmission mode in which CSI-IM is set, an interference measurement for calculating CQI is derived based on CSI-IM. Specifically, in a transmission mode in which CSI-IM is set, an interference measurement for deriving a CQI value corresponding to the CSI process is derived based only on CSI-IM resources associated with the CSI process. The RS or IM used in channel measurement for calculating CSI is also referred to as a second RS.

  Note that the terminal device 1 may perform (or derive) interference measurement for calculating the CQI based on the CRS. For example, when CSI-IM is not set, an interference measurement for calculating CQI based on CRS may be derived.

  It should be noted that the channel and / or interference for calculating CQI may be used for the channel and / or interference for calculating PMI or RI as well.

  Below, the detail of a LAA cell is demonstrated.

  The frequency used by the LAA cell is shared with other communication systems and / or other LTE operators. In frequency sharing, LAA cells require fairness with other communication systems and / or other LTE operators. For example, a fair frequency sharing technique (method) is necessary in a communication system used in an LAA cell. In other words, the LAA cell is a cell that performs a communication method (communication procedure) to which a fair frequency sharing technique can be applied (used).

  An example of a fair frequency sharing technique is LBT (Listen-Before-Talk). Before transmitting a signal using a certain base station or terminal (component carrier, cell), LBT performs interference power (interference signal, received power, received signal, noise power, noise signal), etc. of that frequency. By measuring (detecting), the frequency is idle (free, not congested, Absence, Clear) or busy (not free, congested, Presence, Occupied) is identified (detected, assumed, determined). If the frequency is identified as idle based on the LBT, the LAA cell can transmit a signal at a predetermined timing at that frequency. If it is determined that the frequency is busy based on the LBT, the LAA cell does not transmit a signal at a predetermined timing at that frequency. The LBT can be controlled so as not to interfere with signals transmitted by other base stations and / or terminals including other communication systems and / or other LTE operators.

  The LBT procedure is defined as a mechanism that applies a CCA (Clear Channel Assessment) check before a base station or terminal uses its frequency (channel). The CCA performs power detection or signal detection to determine the presence or absence of other signals on the channel to identify whether the frequency is idle or busy. In the present embodiment, the definition of CCA may be equivalent to the definition of LBT. In the present embodiment, CCA is also referred to as carrier sense.

  In CCA, various methods can be used as a method for determining the presence or absence of other signals. For example, CCA is determined based on whether the interference power at a certain frequency exceeds a certain threshold. Also, for example, CCA is determined based on whether the received power of a predetermined signal or channel at a certain frequency exceeds a certain threshold value. The threshold value may be defined in advance. The threshold may be set from the base station or another terminal. The threshold value may be determined (set) based at least on other values (parameters) such as transmission power (maximum transmission power).

  As an LBT procedure, ICCA (Initial CCA, single sensing, LBT category 2, FBE: Frame-based Equipment) capable of transmitting a signal after performing one CCA check, and a predetermined number of CCA checks were performed. There is ECCA (Extended CCA, multiple sensing, LBT category 3/4, LBE: Load-based Equipment) capable of transmitting signals later. A period during which the CCA check is performed by the ICCA is called an ICCA period or an ICCA slot length, and is 34 microseconds, for example. The period during which the CCA check is performed by ECCA is referred to as ECCA period or ECCA slot length, and is, for example, 9 microseconds. Further, a period in which the CCA check is performed after the frequency changes from the busy state to the idle state is referred to as a defer period or an ECCA defer period, which is, for example, 34 microseconds.

  Note that the CCA in the LAA cell does not need to be recognized by a terminal connected (set) to the LAA cell.

  When the terminal apparatus 1 can detect transmission after CCA in the LAA cell is completed, the terminal apparatus 1 may consider that the transmission continues several subframes after detecting the first transmission. Several subframes in which transmission continues are also referred to as a transmission burst. In particular, several subframes in which PDSCH transmission is continued are referred to as PDSCH transmission bursts. The PDSCH transmission burst may include channels and / or signals other than PDSCH. For example, the PDSCH transmission burst may be transmitted including PDSCH and DS. In particular, several subframes in which only the DS is transmitted are referred to as a DS transmission burst. The number of subframes transmitted continuously by the transmission burst may be set in the terminal device 1 by the RRC message.

  When the terminal apparatus detects a reservation signal included at the head of the transmission burst, the terminal apparatus can detect the transmission burst. The terminal apparatus regards several subframes as a transmission burst from the subframes in which the reservation signal is detected. When a first synchronization signal, a second synchronization signal, or a third synchronization signal, which will be described later, is detected instead of the reservation signal, the terminal apparatus sets the subsequent several subframes as transmission bursts. It can be considered.

  Further, the terminal device can detect the transmission burst when the information of the subframe specifying the transmission burst included in the DCI is decoded. The DCI is notified by being included in PDCCH or EPDCCH arranged in CSS. Further, the DCI may be notified by being included in the PDCCH or EPDCCH arranged in the USS.

  The LAA cell may be defined as a cell different from the secondary cell using the allocated frequency. For example, the LAA cell is set differently from the setting of the secondary cell using the allocated frequency. Some of the parameters set in the LAA cell are not set in the secondary cell using the allocated frequency. Some of the parameters set in the secondary cell using the allocated frequency are not set in the LAA cell. In the present embodiment, the LAA cell is described as a cell different from the primary cell and the secondary cell, but the LAA cell may be defined as one of the secondary cells. The conventional secondary cell is also referred to as a first secondary cell, and the LAA cell is also referred to as a second secondary cell. The conventional primary cell and secondary cell are also referred to as a first serving cell, and the LAA cell is also referred to as a second serving cell.

  Also, the LAA cell may be different from the conventional frame configuration type. For example, the conventional serving cell uses (sets) the first frame configuration type (FDD, frame structure type 1) or the second frame configuration type (TDD, frame structure type 2), while the LAA cell A third frame structure type (frame structure type 3) is used (set). Note that the LAA cell may use the first frame configuration type or the second frame configuration type (may be set).

  Further, the third frame configuration type is preferably a frame configuration type having characteristics of an FDD cell while being a TDD cell in which uplink and downlink can be transmitted at the same frequency. For example, the third frame configuration type includes an uplink subframe, a downlink subframe, and a special subframe, and the PUSCH scheduled from the uplink grant after receiving the uplink grant is The interval until transmission or the interval of HARQ feedback for the PDSCH after receiving the PDSCH may be the same as that of the FDD cell.

  The third frame configuration type is preferably a frame configuration type that does not depend on a conventional TDD UL / DL configuration (TDD uplink / downlink configuration). For example, the uplink subframe, the downlink subframe, and the special subframe may be set aperiodically with respect to the radio frame. For example, the uplink subframe, the downlink subframe, and the special subframe may be determined based on PDCCH or EPDCCH.

  Here, the non-assigned frequency is a frequency different from the assigned frequency assigned as a dedicated frequency to a predetermined operator. For example, the unassigned frequency is a frequency used by the wireless LAN. For example, the non-assigned frequency is a frequency that is not set in the conventional LTE, and the assigned frequency is a frequency that can be set in the conventional LTE. In the present embodiment, the frequency set in the LAA cell is described as an unassigned frequency, but is not limited to this. That is, the unassigned frequency can be replaced with a frequency set in the LAA cell. For example, the non-assigned frequency is a frequency that cannot be set in the primary cell and can be set only in the secondary cell. For example, unassigned frequencies also include frequencies that are shared with multiple operators. Further, for example, the unassigned frequency is a frequency that is set only for a cell that is set, assumed, and / or processed differently from a conventional primary cell or secondary cell.

  The LAA cell may be a cell that uses a scheme different from the conventional scheme with regard to the configuration and communication procedure of radio frames, physical signals, and / or physical channels in LTE.

For example, in the LAA cell, a predetermined signal and / or channel set (transmitted) in the primary cell and / or the secondary cell is not set (transmitted). The predetermined signal and / or channel includes CRS, DS, PDCCH, EPDCCH, PDSCH, PSS, SSS, PBCH, PHICH, PCFICH, CSI-RS, and / or SIB. For example, signals and / or channels that are not set in the LAA cell are as follows. The signals and / or channels described below may be used in combination. In the present embodiment, signals and / or channels that are not set in the LAA cell may be read as signals and / or channels that the terminal does not expect from the LAA cell.
(1) In the LAA cell, physical layer control information is not transmitted on the PDCCH, but is transmitted only on the EPDCCH.
(2) In the LAA cell, CRS, DMRS, URS, PDCCH, EPDCCH and / or PDSCH are not transmitted in all subframes even in a subframe that is activated (on), and the terminal transmits in all subframes. Do not assume that it is.
(3) In the LAA cell, the terminal assumes that DS, PSS, and / or SSS are transmitted in a subframe that is activated (ON).
(4) In the LAA cell, the terminal is notified of information on CRS mapping for each subframe, and makes a CRS mapping assumption based on the information. For example, the CRS mapping assumption is not mapped to all resource elements of that subframe. The assumption of CRS mapping is not mapped to some resource elements of the subframe (for example, all resource elements in the first two OFDM symbols). CRS mapping assumptions are mapped to all resource elements of that subframe. Also, for example, information on CRS mapping is notified from the LAA cell or a cell different from the LAA cell. Information on CRS mapping is included in DCI and is notified by PDCCH or EPDCCH.

  Further, for example, in the LAA cell, a predetermined signal and / or channel that is not set (transmitted) in the primary cell and / or the secondary cell is set (transmitted).

  Also, for example, in the LAA cell, only downlink component carriers or subframes are defined, and only downlink signals and / or channels are transmitted. That is, in the LAA cell, no uplink component carrier or subframe is defined, and no uplink signal and / or channel is transmitted.

  In addition, for example, in a LAA cell, a DCI (Downlink Control Information) format that can be supported is different from a DCI format that can correspond to a primary cell and / or a secondary cell. A DCI format corresponding only to the LAA cell is defined. The DCI format corresponding to the LAA cell includes control information effective only for the LAA cell.

  The terminal device can recognize the LAA cell by a parameter by the higher layer. For example, the terminal device can recognize a conventional cell (band) or LAA cell (LAA band) from the parameter for reporting the center frequency of the element carrier. In this case, the information related to the center frequency is associated with the cell (band) type.

  Further, for example, in the LAA cell, the assumption of signals and / or channels is different from that of the conventional secondary cell.

First, the assumption of the signal and / or channel in the conventional secondary cell is demonstrated. A terminal satisfying a part or all of the following conditions, except for transmission of DS, has PSS, SSS, PBCH, CRS, PCFICH, PDSCH, PDCCH, EPDCCH, PHICH, DMRS and / or CSI-RS as its secondary cell. Assume that it may not be sent by. The terminal also assumes that the DS is always transmitted by the secondary cell. Further, the assumption continues until a subframe in which an activation command (command for activation) is received in a secondary cell at a certain carrier frequency of the terminal.
(1) The terminal supports settings (parameters) related to the DS.
(2) The RRM measurement based on DS is set in the secondary cell of the terminal.
(3) The secondary cell is in a deactivated state (deactivated state).
(4) The terminal is not set to receive MBMS by the upper layer in the secondary cell.

  In addition, when the secondary cell is in an activated state (activated state), the terminal performs PSS, SSS, PBCH, CRS, PCFICH, PDSCH, PDCCH, in a set predetermined subframe or all subframes. Assume that EPDCCH, PHICH, DMRS and / or CSI-RS are transmitted by the secondary cell.

Next, an example of signal and / or channel assumption in the LAA cell will be described. A terminal that satisfies some or all of the following conditions includes the transmission of DS, PSS, SSS, PBCH, CRS, PCFICH, PDSCH, PDCCH, EPDCCH, PHICH, DMRS, and / or CSI-RS in its LAA cell Assume that it may not be sent by. Further, the assumption continues until a subframe in which an activation command (command for activation) is received in a secondary cell at a certain carrier frequency of the terminal.
(1) The terminal supports settings (parameters) related to the DS.
(2) The RRM measurement based on DS is set in the LAA cell of the terminal.
(3) The LAA cell is deactivated (inactivated state).
(4) The terminal is not set to receive MBMS by the upper layer in the LAA cell.

  Another example of signal and / or channel assumption in the LAA cell will be described. When the LAA cell is in a deactivated state, the signal and / or channel assumption in the LAA cell is the same as the signal and / or channel assumption in the conventional secondary cell. When the LAA cell is in an activated state, the signal and / or channel assumptions in the LAA cell are different from the signal and / or channel assumptions in the conventional secondary cell. For example, when the LAA cell is activated (activated state), the terminal determines that the LAA cell is PSS, SSS, PBCH, CRS, except for a predetermined subframe set in the LAA cell. Assume that PCFICH, PDSCH, PDCCH, EPDCCH, PHICH, DMRS and / or CSI-RS may not be transmitted. Details thereof will be described later.

  In addition, although it has been shown that CCA is performed in one subframe, the time (period) for performing CCA is not limited to this. The time for performing CCA may vary for each LAA cell, for each timing of CCA, and for each execution of CCA. For example, CCA is performed at a time based on a predetermined time slot (time interval, time domain). The predetermined time slot may be defined or set by a time obtained by dividing one subframe into a predetermined number. The predetermined time slot may be defined or set by a predetermined number of subframes.

  In the present embodiment, the size of the field in the time domain, such as the time for performing CCA (time slot) and the time during which a channel and / or signal is transmitted (can be transmitted) in a certain subframe, is a predetermined time unit. Can be expressed using. For example, the size of the field in the time domain is expressed as several time units Ts. Ts is 1 / (15000 * 2048) seconds. For example, the time of one subframe is 30720 * Ts (1 millisecond). For example, one ICCA slot length or defer period is 1044 * Ts (about 33.98 microseconds), or 1045 * Ts (about 34.02 microseconds). For example, one ECCA slot length is 276 * Ts (about 8.984 microseconds), or 277 * Ts (about 9.017 microseconds). For example, one ECCA slot length is 307 * Ts (about 9.993 microseconds), or 308 * Ts (about 10.03 microseconds).

  Further, whether or not a channel and / or a signal (including a reservation signal) can be transmitted from a symbol in the middle of a subframe in which the LAA cell is present may be set for the terminal or the LAA cell. For example, information indicating whether or not such transmission is possible is set in the terminal regarding the LAA cell by RRC signaling. Based on the information, the terminal switches processing related to reception (monitoring, recognition, decoding) in the LAA cell.

  In addition, subframes that can be transmitted from intermediate symbols (including subframes that can be transmitted to intermediate symbols) may be all subframes in the LAA cell. Further, the subframe that can be transmitted from a halfway symbol may be a subframe previously defined for the LAA cell or a set subframe.

  Also, subframes that can be transmitted from intermediate symbols (including subframes that can be transmitted up to intermediate symbols) are set, notified, or determined based on the TDD uplink downlink configuration (UL / DL configuration). Can. For example, such a subframe is a subframe notified (designated) as a special subframe in the UL / DL setting. The special subframe in the LAA cell is a subframe including at least one of three fields of DwPTS (Downlink Pilot Time Slot), GP (Guard Period), and UpPTS (Uplink Pilot Time Slot). The setting related to the special subframe in the LAA cell may be set or notified by RRC signaling, PDCCH or EPDCCH signaling. This setting sets the length of time for at least one of DwPTS, GP and UpPTS. This setting is index information indicating candidates for a predetermined length of time. This setting can use the same length of time as DwPTS, GP, and UpPTS used in the special subframe setting set in the conventional TDD cell. That is, the length of time during which transmission is possible in a certain subframe is determined based on one of DwPTS, GP, and UpPTS.

  In the present embodiment, the reservation signal can be a signal that can be received by an LAA cell different from the LAA cell that is transmitting the reservation signal. For example, an LAA cell different from the LAA cell that transmits the reservation signal is an LAA cell (adjacent LAA cell) that is adjacent to the LAA cell that transmits the reservation signal. For example, the reservation signal includes information regarding a transmission status (usage status) of a predetermined subframe and / or symbol in the LAA cell. When an LAA cell that is different from the LAA cell that is transmitting a reservation signal receives the reservation signal, the LAA cell that has received the reservation signal uses a predetermined subframe and / or symbol based on the reservation signal. Recognize the transmission status and perform scheduling according to the status.

  In addition, the LAA cell that has received the reservation signal may perform LBT before transmitting the channel and / or signal. The LBT is performed based on the received reservation signal. For example, in the LBT, scheduling including resource allocation and MCS selection is performed in consideration of a channel and / or signal transmitted (assumed to be transmitted) by the LAA cell that transmitted the reservation signal.

  In addition, when the LAA cell that has received the reservation signal performs scheduling for transmitting a channel and / or signal based on the reservation signal, one or more LAA cells including the LAA cell that has transmitted the reservation signal are transmitted by a predetermined method. Information about the scheduling can be notified to the LAA cell. For example, the predetermined method is a method of transmitting a predetermined channel and / or signal including a reservation signal. Further, for example, the predetermined method is a method of notifying through a backhaul such as an X2 interface.

  Further, in the carrier aggregation and / or dual connectivity, the conventional terminal can set up to five serving cells, but the terminal in the present embodiment can expand the maximum number of serving cells that can be set. That is, the terminal in this embodiment can set up more than five serving cells. For example, the terminal in this embodiment can set up to 16 or 32 serving cells. For example, more than five serving cells set in the terminal in the present embodiment include LAA cells. In addition, all of the five serving cells set in the terminal in the present embodiment may be LAA cells.

In addition, when more than five serving cells can be set, settings for some serving cells may be different from settings for a conventional serving cell (ie, a conventional secondary cell). For example, the following is different regarding the setting. The settings described below may be used in combination.
(1) The terminal is configured with up to 5 conventional serving cells and up to 11 or 27 serving cells different from the conventional one. That is, the terminal is configured with up to four conventional secondary cells in addition to the conventional primary cell, and with up to 11 or 27 secondary cells different from the conventional one.
(2) The setting regarding the serving cell (secondary cell) different from the conventional one includes the setting regarding the LAA cell. For example, in addition to the conventional primary cell, the terminal sets up to four secondary cells that do not include settings related to the LAA cell, and sets up to 11 or 27 secondary cells different from the conventional one.

Further, when more than five serving cells can be set, the base station (including the LAA cell) and / or the terminal can perform processing or assumption different from that when setting up to five serving cells. For example, regarding the processing or assumption, the following is different. The processes or assumptions described below may be used in combination.
(1) The terminal assumes that PDCCH, EPDCCH and / or PDSCH are simultaneously transmitted (received) from a maximum of five serving cells even when more than five serving cells are set. Thereby, the terminal can use the same method as before for reception of PDCCH, EPDCCH and / or PDSCH and transmission of HARQ-ACK for the PDSCH.
(2) When more than five serving cells are set, the terminal sets a combination (group) of cells that perform HARQ-ACK bundling for the PDSCH in those serving cells. For example, all serving cells, all secondary cells, all LAA cells, or all non-conventional secondary cells each include information (setting) on HARQ-ACK bundling between serving cells. For example, information related to HARQ-ACK bundling between serving cells is an identifier (index, ID) for performing bundling. For example, HARQ-ACK is bundled across cells having the same identifier for bundling. The bundling is performed by a logical product operation on the target HARQ-ACK. The maximum number of identifiers for bundling can be 5. Further, the maximum number of identifiers for performing bundling can be set to 5 including the number of cells for which bundling is not performed. That is, the maximum number of groups that perform bundling beyond the serving cell can be five. Thereby, the terminal can use the same method as before for reception of PDCCH, EPDCCH and / or PDSCH and transmission of HARQ-ACK for the PDSCH.
(3) When more than five serving cells are set, the terminal sets a cell combination (group) for performing HARQ-ACK multiplexing on the PDSCH in those serving cells. When a combination (group) of cells that multiplex HARQ-ACK with respect to PDSCH is set, the multiplexed HARQ-ACK is transmitted by PUCCH or PUSCH based on the group. In each group, the maximum number of serving cells to be multiplexed is defined or set. The maximum number is defined or set based on the maximum number of serving cells set in the terminal. For example, the maximum number is the same as the maximum number of serving cells set in the terminal, or half the maximum number of serving cells set in the terminal. Further, the maximum number of PUCCHs transmitted simultaneously is defined or set based on the maximum number of serving cells multiplexed in each group and the maximum number of serving cells set in the terminal.

  In other words, the number of set first serving cells (that is, primary cells and / or secondary cells) is a predetermined number (that is, 5) or less, and the set first serving cells and second serving cells ( That is, the total of LAA cells) exceeds the predetermined number.

Next, terminal capabilities related to LAA will be described. Based on an instruction from the base station, the terminal notifies (transmits) information (terminal capability) on the capability (capability) of the terminal to the base station through RRC signaling. The terminal capability for a certain function (feature) is notified (transmitted) when the function (feature) is supported, and is not notified (transmitted) when the function (feature) is not supported. In addition, the terminal capability for a certain function (feature) may be information indicating whether the test and / or implementation of the function (feature) has been completed. For example, the terminal capabilities in this embodiment are as follows. The terminal capabilities described below may be used in combination.
(1) Terminal capabilities related to support of LAA cells and terminal capabilities related to support of setting of more than five serving cells are defined independently. For example, a terminal that supports LAA cells supports setting up more than five serving cells. That is, a terminal that does not support setting of more than five serving cells does not support LAA cells. In that case, a terminal that supports setting of more than five serving cells may or may not support the LAA cell.
(2) The terminal capabilities related to support of LAA cells and the terminal capabilities related to support of setting of more than five serving cells are defined independently. For example, a terminal that supports setting up more than five serving cells supports LAA cells. That is, a terminal that does not support the LAA cell does not support setting of more than five serving cells. In that case, the terminal supporting the LAA cell may or may not support setting of more than five serving cells.
(3) The terminal capability related to the downlink in the LAA cell and the terminal capability related to the uplink in the LAA cell are defined independently. For example, a terminal that supports uplink in the LAA cell supports downlink in the LAA cell. That is, a terminal that does not support the downlink in the LAA cell does not support the uplink in the LAA cell. In that case, the terminal that supports the downlink in the LAA cell may or may not support the uplink in the LAA cell.
(4) The terminal capabilities related to LAA cell support include support for transmission modes set only in the LAA cell.
(5) The terminal capabilities related to the downlink in the setting of more than five serving cells and the terminal capabilities related to the uplink in the setting of more than five serving cells are defined independently. For example, a terminal that supports uplink in a configuration of more than five serving cells supports a downlink in a configuration of more than five serving cells. That is, a terminal that does not support the downlink in the configuration of more than five serving cells does not support the uplink in the configuration of more than five serving cells. In that case, the terminal that supports the downlink in the configuration of more than five serving cells may or may not support the uplink in the configuration of more than five serving cells.
(6) In the terminal capability in setting more than five serving cells, the terminal capability supporting the setting of up to 16 downlink serving cells (component carriers) and the terminal capability supporting the setting of up to 32 downlink serving cells are: Are defined independently. In addition, a terminal that supports setting of up to 16 downlink serving cells supports setting of at least one uplink serving cell. A terminal that supports setting up to 32 downlink serving cells supports setting up at least two uplink serving cells. That is, a terminal that supports setting of up to 16 downlink serving cells may not support setting of two or more uplink serving cells.
(7) The terminal capability related to the support of the LAA cell is notified based on the frequency (band) used in the LAA cell. For example, in the notification of the frequency or combination of frequencies supported by the terminal, if the notified frequency or combination of frequencies includes at least one frequency used in the LAA cell, the terminal implicitly supports the LAA cell. Notice. That is, if the notified frequency or combination of frequencies does not include any frequency used in the LAA cell, the terminal implicitly notifies that it does not support the LAA cell.

  Further, in the present embodiment, the case where the LAA cell transmits PDCCH or EPDCCH that notifies DCI for PDSCH transmitted in the LAA cell has been described (that is, in the case of self-scheduling), but the present invention is not limited to this. Is not to be done. For example, even when a serving cell different from the LAA cell transmits PDCCH or EPDCCH for notifying DCI for PDSCH transmitted in the LAA cell (that is, in the case of cross-carrier scheduling), this embodiment will be described. Applied methods are applicable.

  Further, in the present embodiment, information for recognizing a symbol on which a channel and / or signal is transmitted may be based on a symbol on which a channel and / or signal is not transmitted. For example, the information is information indicating the last symbol of a symbol for which a channel and / or signal is not transmitted. In addition, information for recognizing a symbol on which a channel and / or signal is transmitted may be determined based on other information or parameters.

  In the present embodiment, a symbol for transmitting a channel and / or signal may be set (notified or defined) independently of the channel and / or signal. In other words, information for recognizing a symbol for transmitting a channel and / or a signal and a notification method thereof can be set (notified or defined) independently for each channel and / or signal. For example, information for recognizing a channel and / or symbol on which a signal is transmitted and a notification method thereof can be set (notified and specified) independently for PDSCH and EPDCCH.

  In this embodiment, a symbol / subframe in which a channel and / or signal is not transmitted (cannot be transmitted) is a symbol / subframe in which a channel and / or signal is not assumed to be transmitted (can be transmitted) from the viewpoint of the terminal It is good. That is, the terminal can consider that the LAA cell is not transmitting a channel and / or signal in the symbol / subframe.

  In the present embodiment, the symbol / subframe in which the channel and / or signal is transmitted (can be transmitted) is the symbol / subframe in which the channel and / or signal may be transmitted from the viewpoint of the terminal. It is good. That is, the terminal may consider that the LAA cell may or may not be transmitting a channel and / or signal in that symbol / subframe.

  Further, in the present embodiment, a symbol / subframe in which a channel and / or signal is transmitted (transmittable) is a symbol / subframe that is assumed to be transmitted from the terminal point of view. Also good. That is, the terminal can consider that the LAA cell always transmits a channel and / or signal in the symbol / subframe.

  Next, an example of the configuration of the downlink reference signal in the LAA cell will be described.

FIG. 5 is a diagram illustrating an example of a configuration of a downlink reference signal. As an example, the CRS can be arranged in the REs of R0 to R3. R0 is the RE in which the CRS of the antenna port 0 is arranged, R1 is the RE in which the CRS of the antenna port 1 is arranged, R2 is the RE in which the CRS of the antenna port 2 is arranged, and R3 is the CRS of the antenna port 3. An example of RE is shown. Note that the CRS may be arranged in the frequency direction depending on a parameter related to the cell identifier. Specifically, based on the value of N ^cell _ID mod6, the index k at which the RE specifies the arrangement is increased. Here, N ^cell _ID is the value of the physical cell identifier. The DMRS can be placed in the REs of D1 to D2. D1 shows an example of RE in which DMRSs of antenna ports 7, 8, 11, and 13 are arranged, and D2 shows an example of RE in which DMRS of antenna ports 9, 10, 12, and 14 are arranged. The CSI-RS can be arranged in C1 to C4 REs. C0 is an RE in which the CSI-RS of the antenna ports 15 and 16 is arranged, C1 is an RE in which the CSI-RS of the antenna ports 17 and 18 is arranged, and C2 is an RE in which the CSI-RS of the antenna ports 19 and 20 is arranged. , C3 shows an example of RE in which CSI-RSs of antenna ports 21 and 22 are arranged. CSI-RS may be arranged in OFDM symbol # 5 or # 6 in slot 0 and RE in OFDM symbol # 1, # 2 or # 3 in slot 1. In CSI-RS, the RE to be arranged is instructed based on the upper layer parameters.

  An example of the configuration of the synchronization signal in the LAA cell will be described.

  FIG. 6 is a diagram illustrating an example of a configuration of a synchronization signal in the LAA cell. The synchronization signal in the LAA cell includes the first synchronization signal (Enhanced Primary Synchronization Signal (EPSS), Unlicensed Primary Synchronization Signal (UPSS), Primary Synchronization Signal for LAA cell, Second Primary synchronization signal) and second synchronization signal (Enhanced Secondary Synchronization Signal (ESSS), Unlicensed Secondary Synchronization Signal (USSS), Secondary Synchronization Signal for LAA cells, Second Secondary synchronization signal). Also, the synchronization signal in the LAA cell is transmitted in the same frequency band as the system bandwidth (or downlink bandwidth) used for downlink transmission. For example, when the system bandwidth is set at 5 MHz, the synchronization signal is also arranged so as to be within 5 MHz. Note that the system bandwidth or the downlink bandwidth (uplink bandwidth) may be set in consideration of the guard band.

  The first synchronization signal is generated mainly based on the Zadoff-Chu sequence.

As the sequence length N _ZC of the Zadoff-Chu sequence of the first synchronization signal, a value related to the frequency band in which the first synchronization signal is arranged is used.

As an example, the value of the number of subcarriers used in the arranged frequency band is used. As a specific example, when 5 MHz (25 PRB, 300 subcarriers, 300 resource elements) is allocated, 300 is used as the sequence length N _ZC . Specific examples, 10MHz (50PRB, 600 subcarriers, 600 resource elements) when placed in sequence length N _ZC 600 is used. As a specific example, when placed in a 20MHz (100PRB, 1200 subcarriers, 1200 resource element), sequence length N _ZC 1200 is used.

As an example, the largest odd value of the number of subcarriers used in the arranged frequency band is used. As a specific example, when it is arranged at 5 MHz (25 PRB, 300 subcarriers, 300 resource elements), 299 is used as the sequence length N _ZC . As a specific example, in the case of 10 MHz (50 PRB, 600 subcarriers, 600 resource elements), 599 is used as the sequence length N _ZC . As a specific example, when placed in a 20MHz (100PRB, 1200 subcarriers, 1200 resource element), sequence length N _ZC is 1199 is used.

As an example, the maximum prime number value below the value obtained by dividing the number of subcarriers used in the allocated frequency band by 2 is used. As a specific example, in the case of arrangement at 5 MHz (25 PRB, 300 subcarriers, 300 resource elements), 149 is used as the sequence length N _ZC . As a specific example, in the case of 10 MHz (50 PRB, 600 subcarriers, 600 resource elements), 241 is used as the sequence length N _ZC . As a specific example, when 20 MHz (100 PRB, 1200 subcarrier, 1200 resource element) is allocated, 599 is used as the sequence length N _ZC .

As an example, a value obtained by doubling the maximum prime number of the following values obtained by dividing the number of subcarriers used in the arranged frequency band by 2 and adding 1 is used. As a specific example, when it is arranged at 5 MHz (25 PRB, 300 subcarriers, 300 resource elements), 299 is used as the sequence length N _ZC . As a specific example, when placed in a 10MHz (50PRB, 600 subcarriers, 600 resource elements), sequence length N _ZC 483 is used. As a specific example, when placed in a 20MHz (100PRB, 1200 subcarriers, 1200 resource element), sequence length N _ZC is 1199 is used.

The sequence length N _ZC of the Zadoff-Chu sequence of the first synchronization signal is determined in relation to the frequency band in which the second synchronization signal is arranged. As an example, the sequence length N _ZC of the Zadoff-Chu sequence of the first synchronization signal is the same as the subcarrier (resource element) in which the second synchronization signal is arranged. As a specific example, sequence length N _ZC of the Zadoff-Chu sequence of the first synchronization signal, when subcarriers second synchronization signal is located (resource element) is 300, N _ZC is also 300.

The sequence length N _ZC of the Zadoff-Chu sequence of the first synchronization signal is different from the sequence length of the Zadoff-Chu sequence used in the uplink reference signal.

Note that the sequence length N _ZC of the Zadoff-Chu sequence of the first synchronization signal may be the same sequence length as the primary synchronization signal. That is, the sequence length N _ZC of the Zadoff-Chu sequence of the first synchronization signal may be 63.

The root index of the first synchronization signal is related to the frequency band in which the first synchronization signal is arranged. As the value of the root index of the first synchronization signal, a value related to the sequence length N _ZC of the Zadoff-Chu sequence of the first synchronization signal is used. The number of root indexes of the first synchronization signal is related to the sequence length N _ZC .

  Note that the root index of the first synchronization signal may be the same as that of the primary synchronization signal. That is, the route index of the first synchronization signal has three types of 25, 29, and 34.

  Note that the route index of the first synchronization signal may be related to the operator identifier. In other words, the route index is uniquely determined by the operator identifier.

  The first synchronization signals are arranged in the order of the sequences generated from the low frequency side. The sequences may be arranged in the order of the sequences generated from the high frequency side.

  The second synchronization signal is generated mainly based on the M sequence.

  As the sequence length of the M sequence of the second synchronization signal, a value related to the frequency band in which the second synchronization signal is arranged is used.

  As an example, a value obtained by subtracting 1 from the maximum value that can be taken by the n-th power of 2 is used below the value obtained by dividing the number of subcarriers used in the arranged frequency band by 2. As a specific example, when arranged at 5 MHz (25 PRB, 300 subcarriers, 300 resource elements), a sequence length of 127 is used. As a specific example, 255 is used as the sequence length when 10 MHz (50 PRB, 600 subcarriers, 600 resource elements) is allocated. As a specific example, 511 is used as the sequence length in the case of being arranged at 20 MHz (100 PRB, 1200 subcarriers, 1200 resource elements).

  As an example, a value obtained by subtracting 1 from the maximum value that can be taken by the n-th power of 2 below the value obtained by dividing the number of subcarriers used in the arranged frequency band by 2, and a value that is a prime number Used. As a specific example, when arranged at 5 MHz (25 PRB, 300 subcarriers, 300 resource elements) or 10 MHz (50 PRB, 600 subcarriers, 600 resource elements), 127 is used as the sequence length. As a specific example, 511 is used as the sequence length in the case of being arranged at 20 MHz (100 PRB, 1200 subcarriers, 1200 resource elements).

  Note that the sequence length of the M sequence of the second synchronization signal may be the same sequence length as the secondary synchronization signal. That is, the sequence length of the M sequence of the second synchronization signal may be 31.

  The second synchronization signal is configured based on a combination of a plurality of M sequences. For example, it is configured based on a combination of two types of M series. In this case, two types of M-sequence signals may be sequentially arranged for each sequence in the frequency domain. Alternatively, the two types of M sequences may be alternately arranged for each resource element (subcarrier) so as to be nested in the frequency domain. For example, you may be comprised based on the combination of three types of M series. In this case, the three types of M-sequence signals may be arranged in order for each sequence in the frequency domain, or may be arranged in order for each resource element so as to be nested.

  The arrangement of the first and second synchronization signals in the resource element will be described.

  The first or second synchronization signal is arranged by repeating the sequence d. As a specific example, as for the first or second synchronization signal, a signal is arranged in the resource element using Expression (0-b). Here, n ′ is an index used for repeated arrangement, and the maximum value of n ′ is a value obtained by multiplying the number of repeated sequences by the sequence d.

The first synchronization signal is arranged around the center frequency. As a specific example, when the sequence length N _ZC is 299, 149 signals are arranged on the high frequency side centering on the DC subcarrier, and 149 signals are arranged on the low frequency side. That is, when the sequence length is 299, the first synchronization signal is arranged at the center of the system bandwidth using 299 resource elements excluding the DC subcarrier.

  The second synchronization signal is arranged around the center frequency. As a specific example, when the second synchronization signal is configured based on a combination of two types of M sequences having a sequence length of 127, 127 signals are arranged on the high frequency side and 127 signals on the low frequency side from the DC subcarrier. The

  The first or second synchronization signal is arranged by repeating the same series of signals in the frequency direction. As a specific example, the first or second synchronization signal may be arranged in a sequence with a period of 6 PRB (72 subcarriers, 72 resource elements) in the frequency direction. When the first or second synchronization signal is arranged at 5 MHz, four or less first or second synchronization signals are arranged, and when the first or second synchronization signal is arranged at 10 MHz, eight or less first or second synchronization signals are arranged. When arranged at 20 MHz, 16 or less first or second synchronization signals may be repeatedly arranged in the frequency direction.

  Further, the arrangement of resource elements in the frequency domain and time domain of the repeated synchronization signal may be different depending on the identifier of the cell to which the first or second synchronization signal is transmitted. As a result, the probability of using the same resource element between adjacent cells is reduced, and the synchronization signal detection accuracy is improved due to the cell repetition effect.

As an example, the first or second synchronization signal is repeatedly arranged in the frequency domain continuously around the center frequency. That is, the resource element in which the first or second synchronization signal is arranged is determined based on the mathematical formula (1-a) in FIG. Here, h is the number of repeated sequences, and n takes a value from 0 to 2hN _M −1.

As an example, the first or second synchronization signal is arranged around an arbitrary subcarrier. That is, the resource element in which the first or second synchronization signal is arranged is determined based on the mathematical formula (1-b) in FIG. Here, n takes a value from 0 to 2N _M −1. k ′ is a subcarrier offset value between the center frequency and the center of the first or second synchronization signal. Note that k ′ may be specified in units of PRBs, and may be m instead of k ′, for example.

As an example, the first or second synchronization signal is arranged at both ends of the bandwidth. That is, the resource element in which the first or second synchronization signal is arranged is determined based on the mathematical formula (1-c) in FIG. When the first or second synchronization signal is arranged on the low frequency side of the both ends of the bandwidth, the above equation is applied, and the first or second synchronization is applied on the high frequency side of the both ends of the bandwidth. If the signal is placed, the lower equation applies. Here, n takes a value from 0 to 2N _M −1.

As an example, the first or second synchronization signal is arranged at equal intervals in the frequency domain with respect to the system bandwidth. That is, the resource element in which the first or second synchronization signal is arranged is determined based on the mathematical formula (1-d) in FIG. Here, n takes a value from 0 to 2N _M −1. Here, J-1 is the number at which the first synchronization signal is arranged, and j takes a value from 0 to J-1. The value of J may be determined in advance. Further, the value of J may be notified from an upper layer. As a specific example, the value of J is determined based on the set system bandwidth. As a specific example, j is determined based on the cell identifier.

  As an example, the first or second synchronization signal is arranged at intervals of several subcarriers. For example, the first or second synchronization signal is arranged at intervals of 4 subcarriers. For example, the first or second synchronization signal is arranged at intervals of 6 subcarriers.

  Note that the above examples may be used in combination. For example, when the first or second synchronization signal is arranged at the center of the bandwidth and at three positions on both ends, both the mathematical formulas (1-a) and (1-c) in FIG. 9 are used.

  Note that the arrangement of the first or second synchronization signal in the resource element may be set in an upper layer. Candidates to be arranged are determined in advance, and the terminal apparatus can recognize the resource element in which the first or second synchronization signal is arranged by the candidate index which is a higher layer parameter. As a specific example, Equation (1-b) in FIG. 9 is used, and k ′ is determined based on the upper layer parameter.

  Note that the first or second synchronization signal may be arranged at the head of the downlink transmission burst. Alternatively, the first or second synchronization signal may be transmitted after the reservation signal transmitted in the downlink transmission burst.

  The first synchronization signal is arranged in the last OFDM symbol of the first slot. The second synchronization signal is arranged in the second to last OFDM symbol of the first slot. Furthermore, the second synchronization signal is arranged in an OFDM symbol in which CRS or CSI-RS is not arranged. As a specific example, the second synchronization signal is arranged in the third and fourth OFDM symbols of the first slot.

  Furthermore, the second synchronization signal may be arranged according to the setting of CRS. For example, when CRS is not transmitted in antenna ports 2 and 3, the second synchronization signal may be arranged in the second OFDM symbol of the first slot and the second slot.

  Further, the second synchronization signal may be arranged based on the setting of CSI-RS. For example, when the CSI-RS is not arranged in the third and fourth OFDM symbols of the second slot, the second synchronization signal may be arranged in the third and fourth OFDM symbols of the second slot. . As a specific example, when the CSI-RS setting index is not set to any one of 1-3, 6-8, and 12-17, the second synchronization signal is the third and fourth OFDM symbols of the second slot. May be arranged. For example, when the CSI-RS is not arranged in the sixth and seventh OFDM symbols of the second slot, the second synchronization signal may be arranged in the sixth and seventh OFDM symbols of the second slot. . As a specific example, when none of 4, 9, 18, and 19 is set as the CSI-RS setting index of the serving cell, the second synchronization signal transmitted from the serving cell is the sixth and seventh in the second slot. It may be arranged in the second OFDM symbol.

  Note that the frequency domain arrangement of the resource elements of the second synchronization signal may differ depending on the arranged OFDM symbols. That is, the index k of the second synchronization signal may be determined based on the index l. As a specific example, the second synchronization signal is arranged using PRB 0 to 5 in the third OFDM symbol of the first slot and PRB 6 to 11 in the fourth OFDM symbol of the first slot. The

  A cell identifier (transmission point identifier) is reported by a combination of a sequence of the first synchronization signal and the second synchronization signal. The terminal device can detect the identifier of the cell to which the first synchronization signal and the second synchronization signal are transmitted by detecting both the first synchronization signal and the second synchronization signal.

  Further, the cell identifier may be broadcasted by a combination of a sequence of the first synchronization signal and the second synchronization signal and a resource element in which those synchronization signals are arranged. As an example, different cell identifiers may be recognized depending on the relative positions where the first synchronization signal and the second synchronization signal are arranged. In other words, the arrangement of the first synchronization signal and the second synchronization signal is determined from the cell identifier.

  Note that the cell identifier may be broadcast only by the first synchronization signal. Note that the cell identifier may be notified only by the second synchronization signal.

  In addition to the cell identifier, an identifier for identifying the operator may be notified by the first synchronization signal and / or the second synchronization signal.

  The synchronization signal may be transmitted according to the minimum system bandwidth that can be transmitted. For example, even if the system bandwidth is set at 10 MHz or 20 MHz, the synchronization signal may be arranged to be within 5 MHz (25 PRB, 300 subcarriers, 300 resource elements) in the frequency domain.

  The synchronization signal may be arranged in an arbitrary subframe in the LAA cell. That is, the synchronization signal may be arranged in subframes other than subframes 0, 1, 5, and 6 in the LAA cell.

  An example of the configuration of the synchronization signal in the LAA cell will be described.

  FIG. 7 is a diagram illustrating an example of a configuration of a synchronization signal in the LAA cell. Hereinafter, differences from the contents described in FIG. 6 will be described. In this example, in addition to the first synchronization signal and the second synchronization signal, a third synchronization signal (TSS (Tertiary Synchronization Signal), USS (Unlicensed Synchronization Signal), second secondary synchronization signal) is arranged. . Note that one or both of the first synchronization signal and the second synchronization signal shown here may not be arranged. That is, the second synchronization signal may not be transmitted from the base station apparatus, and the terminal apparatus can be synchronized with the base station apparatus by the first synchronization signal and the third synchronization signal. Alternatively, the first synchronization signal may not be transmitted from the base station device, and the terminal device can be synchronized with the base station device by the second synchronization signal and the third synchronization signal. Alternatively, the first synchronization signal and the second synchronization signal may not be transmitted from the base station apparatus, and the terminal apparatus can synchronize with the base station apparatus only by the third synchronization signal.

  The third synchronization signal is generated based on the M sequence, but is generated using a sequence different from the second synchronization signal. For example, the third synchronization signal is generated using an M sequence length different from that of the second synchronization signal. For example, the third synchronization signal is composed of one M sequence. For example, a sequence of the third synchronization signal is generated based on parameters (for example, a transmission point identifier and a scramble identifier) designated by an upper layer.

  Note that the third synchronization signal may be generated based on a gold sequence. The third synchronization signal sequence is generated based on the cell identifier (transmission point identifier). Specifically, the third synchronization signal sequence is initialized with a value based on the cell identifier. The cell identifier used for initializing the third synchronization signal sequence is the same as the cell identifier detected by the first and / or second synchronization signal. Note that the cell identifier used for initializing the third synchronization signal sequence may be a parameter (for example, a transmission point identifier or a scramble identifier) indicated by an upper layer.

  The third synchronization signal sequence is arranged in the frequency domain in order.

  The third synchronization signal sequence is initialized with values based on subframes and OFDM symbols. However, the sequences between the third synchronization signals arranged in different subframes and different OFDM symbols are set independently.

  For the arrangement of the third synchronization signal in the frequency direction, the same method as the first and second synchronization signals described above may be used. Specifically, the third synchronization signal is arranged in the resource element using the mathematical formula of FIG.

  The third synchronization signal is arranged in an OFDM symbol in which CRS or CSI-RS is not arranged. As a specific example, the third synchronization signal is arranged in the third and fourth OFDM symbols of the first slot.

  Further, the third synchronization signal may be arranged based on the CRS setting. For example, when CRS is not transmitted in antenna ports 2 and 3, the third synchronization signal may be arranged in the second OFDM symbol of the first slot and the second slot.

  Furthermore, the third synchronization signal may be arranged based on the setting of CSI-RS. For example, when the CSI-RS is not arranged in the third and fourth OFDM symbols of the second slot, the third synchronization signal may be arranged in the third and fourth OFDM symbols of the second slot. . As a specific example, when the serving cell CSI-RS setting index is not set to any one of 1-3, 6-8, and 12-17, the third synchronization signal transmitted from the serving cell is the second slot. You may arrange | position to the 3rd and 4th OFDM symbol. For example, when the CSI-RS is not arranged in the sixth and seventh OFDM symbols of the second slot, the third synchronization signal may be arranged in the sixth and seventh OFDM symbols of the second slot. . As a specific example, when none of 4, 9, 18, and 19 is set as the CSI-RS setting index of the serving cell, the third synchronization signal transmitted from the serving cell is the sixth and seventh of the second slot. It may be arranged in the second OFDM symbol.

  Furthermore, when the first synchronization signal and the second synchronization signal are not transmitted, the third synchronization signal may be arranged based on the setting of CSI-RS. For example, when the CSI-RS is not arranged in the sixth and seventh OFDM symbols of the first slot, the third synchronization signal may be arranged in the sixth and seventh OFDM symbols of the first slot. . As a specific example, when none of 0, 5, 10, and 11 is set as the CSI-RS setting index of the serving cell, the third synchronization signal transmitted from the serving cell is the sixth and seventh of the second slot. It may be arranged in the second OFDM symbol.

  Note that the OFDM symbol in which the third synchronization signal is arranged may be set by an upper layer parameter. The upper layer parameter is, for example, a bitmap indicating each OFDM symbol. However, when the setting is made such that the third synchronization signal is arranged in the OFDM symbol in which the CSI-RS is arranged, the CSI-RS is not set up to be arranged in the OFDM symbol.

  Note that the frequency domain arrangement of the resource elements of the third synchronization signal may differ depending on the arranged OFDM symbols. That is, the index k of the third synchronization signal may be determined based on the index l. As a specific example, the third synchronization signal is arranged using PRB 0 to 5 in the third OFDM symbol of the first slot and PRB 6 to 11 in the fourth OFDM symbol of the first slot. The

  Next, DS in the LAA cell will be described. Hereinafter, the DS in the non-LAA cell is also referred to as the first DS, and the DS in the LAA cell (DS transmitted in the LAA cell) is also referred to as the second DS. The DS period in the LAA cell is also referred to as a second DS period.

The second DS is configured to include the following signals.
(1) One or more first synchronization signals in the second DS period.
(2) One or more second synchronization signals in the second DS period.
(3) CRS of antenna port 0 in DwPTS of all downlink subframes and all special subframes in the second DS period.
(4) Non-zero power CSI-RS in zero or more subframes in the second DS period. The non-zero power CSI-RS is set by RRC signaling.

  The terminal performs measurement based on the set second DS. The measurement is performed using CRS in the second DS or non-zero power CSI-RS in the second DS. Moreover, in the setting regarding the second DS, a plurality of non-zero power CSI-RSs can be set. Note that the measurement may be performed using the first or second synchronization signal.

  Note that the second DS may include a third synchronization signal.

  The second DS may include CSI-IM (zero power CSI-RS). The CSI-IM is used for RSSI measurement. The CSI-IM is set by RRC signaling. Specifically, the CSI-IM is set by a measurement CSI-IM setting (measCSI-IM-Config). The measurement CSI-IM configuration includes a measurement CSI-IM identifier (measCSI-IM-ConfigId), a parameter (resourceConfig) specifying a resource, and a CSI-IM resource in a DS period or DMTC section. Includes a parameter (subframeOffset) that specifies a subframe to be transmitted.

  The second DS may not include the CRS of the antenna port 0. In that case, the DS period includes at least one non-zero power CSI-RS.

  Note that the second DS may include the CRSs of the antenna ports 1, 2, and 3. In that case, a parameter indicating that the antenna port 1, 2, or 3 is included is added to the DS setting.

  Note that the second DS period may be shorter than one subframe. Specifically, it may be transmitted only in one slot (7 OFDM symbols). That is, in the second DS period, 0.5 subframes to 5.5 subframes can be set in units of 0.5 subframes.

  The CSI-RS of the second DS may be associated with a plurality of CSI-RS settings for one cell. That is, one or more CSI-RS resource settings (resourceConfig) may be linked to one measurement CSI-RS ID (measCSI-RS-Id). In this case, transmission is performed at the antenna port 15 using two or more REs from one measurement cell. The terminal apparatus measures one CSI-RSRP and / or CSI-RSRQ using the two or more REs.

  The details of the DS setting (that is, the second DS setting) in the LAA cell will be described below.

  As an example, in the LAA cell, the terminal apparatus defines a plurality of DS transmission timing (transmission subframe, transmission slot, transmission OFDM symbol) candidates in one DMTC. The base station apparatus can transmit the DS using one of a plurality of transmission timing candidates based on the LBT result. The terminal device performs DS blind detection in all of a plurality of transmission timing candidates set or specified in advance, and detects the DS.

  The DS transmission timing candidate is a subframe or slot in which the second synchronization signal included in the DS may be arranged. In other words, a subframe or slot in which the second synchronization signal included in the DS is not likely to be arranged is not a candidate for DS transmission timing. Further, the DS transmission timing candidates are not necessarily subframe 0 or subframe 5. In other words, a DS transmission timing candidate is one of all downlink subframes or slots in DMTC.

  DS transmission timing candidates are specified by higher layer parameters. For example, it may be specified by a bitmap of 6 bits or less. Each bit of the bitmap corresponds to each subframe in DMTC. For example, it may be specified by a bitmap of 12 bits or less. Each bit in the bitmap corresponds to a slot in each subframe in DMTC.

  Also, DS transmission timing candidates may be specified by a plurality of DS settings including subframe offset information from the first subframe of DMTC. The DS setting includes an ID (identifier) of the DS setting, a physical cell identifier, a scramble identifier, a CSI-RS resource setting, and a subframe from the first subframe of the DMTC for designating a DS transmission timing candidate. Offset information. The subframe offset information is an integer from 0 to DMTC period −1 (for example, 5).

  DS transmission timing candidates are individually set for cells (transmission points). For example, the DS transmission timing candidate from cell A (transmission point A) is subframe 0 or 3, and the DS transmission timing candidate from cell B (transmission point B) is subframe 1 or 4. is there. Thereby, DS can be transmitted with resources orthogonal between cells, and a reuse factor can be improved.

  Note that DS transmission timing candidates may be defined in advance. For example, DS transmission timing candidates are all downlink subframes in DMTC.

  When the DS setting is a setting for the serving cell frequency (that is, when the DS setting is a measurement setting for the intra frequency), the DMTC interval may be longer than 6 ms (6 subframes). In this case, a parameter related to the length of the DMTC section is added to the DS setting.

  As an example, in a LAA cell, a terminal device is set with a plurality of DMTC offsets and sections. Then, in one DMTC section, a DS is transmitted with one DS transmission timing candidate. For example, a predetermined subframe or a predetermined slot in the DMTC section. In the DMTC section, a subframe or a slot equal to or less than the measurement gap is set. As a specific example, the DMTC section is set to 6 subframes or less or 12 slots or less.

  The predetermined subframe or the predetermined slot is specified by an upper layer parameter. As a specific example, the higher layer parameter is a subframe or slot offset value from the first subframe of the DMTC section. Further, the predetermined subframe or the predetermined slot may be defined in advance. As a concrete example

  Thereby, in the LAA cell, it is possible to increase the probability that the terminal device detects the DS.

  Hereinafter, differences between the primary synchronization signal and the secondary synchronization signal, and the first synchronization signal, the second synchronization signal, and the third synchronization signal will be described.

  The primary synchronization signal and the secondary synchronization signal are arranged and transmitted at a period of 5 subframes. In particular, the primary synchronization signal is arranged in subframes 0 and 5 in the FDD cell, the subframes 1 and 6 in the TDD cell, and the secondary synchronization signal is arranged in subframes 0 and 5. On the other hand, the first synchronization signal, the second synchronization signal, and the third synchronization signal may be arranged in the same cycle as the DMTC cycle. Furthermore, the first synchronization signal, the second synchronization signal, and the third synchronization signal may not be transmitted depending on the result of the LBT. Further, it is transmitted in any one downlink subframe in the DMTC interval. As a specific example, when a DMTC period of 40 ms is set, the first synchronization signal, the second synchronization signal, and the third synchronization signal are transmitted by any one downlink subframe in a DMTC section represented by 40 ms. Is done. The subframes in which the first synchronization signal, the second synchronization signal, and the third synchronization signal are arranged are not limited to subframes 0, 1, 5, and 6. The subframe in which the first synchronization signal, the second synchronization signal, and the third synchronization signal are arranged may be set in an upper layer. Further, the first synchronization signal, the second synchronization signal, and the third synchronization signal may be arranged at the head of the PDSCH transmission burst.

  The primary synchronization signal and the secondary synchronization signal are arranged so as to overlap the OFDM symbol in which URS or DMRS is arranged. On the other hand, the first synchronization signal, the second synchronization signal, and the third synchronization signal may not be arranged in the OFDM symbol in which URS or DMRS is arranged. Specifically, the CRS, URS, DMRS, and CSI-RS are arranged in an OFDM symbol in which no CRS, URS, DMRS, and CSI-RS are arranged.

  The primary synchronization signal and the secondary synchronization signal are arranged so that the center frequency of the component carrier is at the center of the primary synchronization signal and the secondary synchronization signal. On the other hand, the first synchronization signal, the second synchronization signal, and the third synchronization signal are not necessarily arranged at the center frequency of the component carrier.

  The primary synchronization signal and the secondary synchronization signal are arranged in the TDD cell and the FDD cell and are not arranged in the LAA cell. On the other hand, the first synchronization signal, the second synchronization signal, and the third synchronization signal can be arranged in the TDD cell, the FDD cell, and the LAA cell.

  The primary synchronization signal and the secondary synchronization signal are transmitted using 62 resource elements. On the other hand, the first synchronization signal, the second synchronization signal, and the third synchronization signal are transmitted using resource elements of 62 resource elements or more.

  The terminal device can detect the physical cell identifier by the primary synchronization signal and the secondary synchronization signal. On the other hand, with the first synchronization signal, the second synchronization signal, and the third synchronization signal, the terminal device may detect information identifying the transmission point and information identifying the operator in addition to the physical cell identifier. it can.

  Below, the method of arrangement | positioning (mapping) to the resource element of PDSCH is demonstrated.

  The PDSCH is arranged in order from the frequency direction in the PRB on which the PDSCH is scheduled. However, among the REs in the PRB, PSS, SSS, PBCH, CRS, URS associated with the PDSCH, zero power CSI-RS, non-zero power CSI-RS, and transmission of the EPDCCH associated with the PDSCH The PDSCH is not arranged in the RE used for. Also, PDSCH is not arranged in an OFDM symbol ahead of the OFDM symbol specified by the PDSCH start OFDM symbol information.

That is, the index (k, l) of the resource element in which the PDSCH is arranged starts from the first slot of the subframe, and is the order of the index k on the PRB to which the PDSCH is assigned first, and then the index l. To increase. PDSCH is not arranged in PBCH and RE used for transmission of a synchronization signal. Further, PDSCH is not used in RE assumed by the terminal device when used for CRS. In addition, the PDSCH is not arranged in the RE used for transmission of the URS associated with the PDSCH. In addition, when the DCSCH associated with the PDSCH uses C-RNTI or semi-persistent C-RNTI, the PDSCH is used for transmission of zero power CSI-RS and non-zero power CSI-RS for CSI reporting. When used, it is not placed in the RE assumed by the terminal device. The arrangement of the zero power CSI-RS is given by the setting for zero power CSI-RS. The arrangement of the zero power CSI-RS is given by the configuration of up to 5 reserved CSI-RS resources that are part of the DS configuration. The arrangement of the non-zero power CSI-RS is given by the settings for the non-zero power CSI-RS. Also, the PDSCH is not placed in any PRB pair that carries the EPDCCH associated with that PDSCH. In addition, the index 1 of the first slot of the subframe satisfies 1 _DataStart or less.

  Further, the PDSCH is not arranged in the RE assumed by the terminal device to be used for DS transmission. Below, an example of the assumption of PDSCH mapping by a terminal device when DS and PDSCH are arranged in a certain subframe will be described.

  An example of PDSCH mapping assumption in a subframe including a DS transmission timing candidate will be described. There is a possibility that DS is transmitted in all downlink subframes in the DMTC interval, and even if the DS is transmitted in only one of them, the base station apparatus transmits all downlink subframes in that DMTC interval. In the RE where the DS can be arranged, the PDSCH is not used. The terminal apparatus performs PDSCH decoding on the assumption that no PDSCH is arranged in all REs in which DS signals may be arranged in all downlink subframes in the DMTC section.

That is, when the DS setting in the LAA cell is set, the PDSCH is not arranged in the resource element assumed by the terminal device to be used for transmission of the following signals included in the DS.
(1) CRS of antenna port 0 in DwPTS of all downlink subframes and all special subframes in the DMTC period.
(2) A first synchronization signal in DwPTS of all downlink subframes and all special subframes in the DMTC period.
(3) A second synchronization signal in the DwPTS of all downlink subframes and all special subframes in the DMTC period.
(4) Non-zero power CSI-RS of zero or more subframes within the DMTC period. The non-zero power CSI-RS that is part of the DS is set in the DS configuration.

  The PDSCH is a CRS antenna port other than the CRS antenna port 0 (ie, antenna port 1, 2, or 3) in the DwPTS of all downlink subframes and all special subframes in the DMTC period. ) May not be arranged in the resource element used for transmission. Whether or not to place the resource element is set in the upper layer (DS setting). For example, measurement is performed using resources corresponding to antenna ports other than CRS antenna port 0, or the number of antenna ports for CRS (for example, two or more antenna ports) is set. The PDSCH resource may not be arranged with respect to the antenna port resource. That is, when it is indicated that a plurality of antenna ports are used for CRS, the terminal device does not expect PDSCH to be arranged in the resource corresponding to each antenna port.

  The PDSCH may not be arranged in the resource element used for transmission of the third synchronization signal in the DwPTS of all downlink subframes and all special subframes in the DMTC period. Whether or not to place the resource element is set in the upper layer (DS setting). When the setting related to the third synchronization signal is included in the DS setting, or when it is specified that the third synchronization signal is included in the DS, the terminal device uses the resource in which the third synchronization signal is arranged. Do not expect PDSCH to be placed in

  An example of the assumption of PDSCH mapping in a subframe including DS transmission timing candidates will be described. There is a possibility that a DS may be transmitted in a downlink subframe indicated by an upper layer in the DMTC section, and even if only one of the DSs is transmitted, the base station apparatus may perform an upper layer in the DMTC section. In the RE in which the DS can be arranged in the downlink subframe indicated in (1), it is not used as the PDSCH. The terminal apparatus performs PDSCH decoding on the assumption that the PDSCH is not arranged in all the REs in which the DS signal may be arranged in the downlink subframe indicated in the higher layer in the DMTC section.

  The upper layer information indicating the downlink subframe in which the DS may be transmitted may be a bitmap (bit string). For example, the length of the bitmap may be 6 bits or less. Further, information indicated by each bit of the bitmap may correspond to each subframe in DMTC. For example, when the value of the bit is set to “1”, the DS may be transmitted in the corresponding subframe. When the value of the bit is set to “0”, there is no possibility that the DS is transmitted in the corresponding subframe. The terminal apparatus determines the timing for receiving the DS and the downlink subframe based on the bit information.

That is, when the DS setting in the LAA cell is set, the PDSCH is not arranged in the resource element assumed by the terminal device to be used for transmission of the following signals included in the DS. The predetermined downlink subframe and the predetermined special subframe are indicated by an upper layer.
(1) CRS of antenna port 0 in DwPTS of a predetermined downlink subframe and a predetermined special subframe within the DMTC period.
(2) A first synchronization signal in DwPTS of a predetermined downlink subframe and a predetermined special subframe within the DMTC period.
(3) A second synchronization signal in the DwPTS of a predetermined downlink subframe and a predetermined special subframe within the DMTC period.
(4) Non-zero power CSI-RS of zero or more subframes within the DMTC period. The non-zero power CSI-RS that is part of the DS is set in the DS configuration.

  The PDSCH is a CRS antenna port other than the CRS antenna port 0 in the DwPTS of the predetermined downlink subframe and the predetermined special subframe in the DMTC period (that is, the antenna ports 1, 2, or 3). ) May not be arranged in the resource element used for transmission. Whether or not to place the resource element is set in the upper layer (DS setting).

  The PDSCH may not be arranged in the resource element used for transmission of the third synchronization signal in the DwPTS of the predetermined downlink subframe and the predetermined special subframe in the DMTC period. Whether or not to place the resource element is set in the upper layer (DS setting).

  Note that the predetermined downlink subframe and the predetermined special subframe may be defined in advance. For example, the predetermined downlink subframe may be defined in advance as subframes 0, 3, 5, and 8.

  An example of the assumption of PDSCH mapping in a subframe including DS transmission timing candidates will be described. With the information included in the DCI of the PDCCH and EPDCCH, the terminal device can identify whether or not the DS is transmitted in the DS transmission timing candidate. In other words, the terminal apparatus determines whether the PDSCH is arranged in an RE in which a DS signal may be arranged in a subframe in which the PDCCH and / or EPDCCH schedules the PDSCH by PDCCH and / or EPDCCH signaling. Is instructed.

  Information indicating whether or not the DS included in the PDCCH and / or EPDCCH is transmitted is 1-bit information. If the information indicating whether or not the DS is transmitted is 1 (True, Enable), the DS is being transmitted in the subframe. On the other hand, when the information indicating whether or not the DS is transmitted is 0 (False, Disable), the DS is not transmitted in the subframe. When it is notified that the DS is not transmitted in the subframe and the PDSCH is scheduled in the subframe, the PDSCH is arranged in the RE in which the DS may be arranged. Alternatively, when a plurality of DS transmission timing candidates or a configuration of a plurality of DSs are set, information on whether or not a DS is transmitted may be represented by a plurality of bits. Note that the information on whether or not the DS is transmitted may be the same as the information on whether or not the transmission burst is transmitted.

  The PDCCH and / or EPDCCH is located in the USS. Note that the PDCCH may be arranged in the CSS.

That is, when the DS setting in the LAA cell is set, the PDSCH is not arranged in the resource element assumed by the terminal device to be used for transmission of the following signals included in the DS. The predetermined downlink subframe and the predetermined special subframe are subframes indicated by DCI.
(1) CRS of antenna port 0 in DwPTS of a predetermined downlink subframe and a predetermined special subframe within the DMTC period.
(2) A first synchronization signal in DwPTS of a predetermined downlink subframe and a predetermined special subframe within the DMTC period.
(3) A second synchronization signal in the DwPTS of a predetermined downlink subframe and a predetermined special subframe within the DMTC period.
(4) Non-zero power CSI-RS of zero or more subframes within the DMTC period. The non-zero power CSI-RS that is part of the DS is set in the DS configuration.

  The PDSCH is a CRS antenna port other than the CRS antenna port 0 in the DwPTS of the predetermined downlink subframe and the predetermined special subframe in the DMTC period (that is, the antenna ports 1, 2, or 3). ) May not be arranged in the resource element used for transmission. Whether or not to place the resource element is set in the upper layer (DS setting).

  The PDSCH may not be arranged in the resource element used for transmission of the third synchronization signal in the DwPTS of the predetermined downlink subframe and the predetermined special subframe in the DMTC period. Whether or not to place the resource element is set in the upper layer (DS setting).

  An example of the assumption of PDSCH mapping in a subframe including DS transmission timing candidates will be described. If a transmission burst burst overlaps with a measurement period set in DMTC, the DS can be transmitted without performing LBT for DS transmission. Therefore, there is no need to increase the probability of transmission using a plurality of transmission timing candidates. That is, if the terminal apparatus can recognize the transmission burst and if the transmission burst and at least one DS transmission timing candidate overlap in the time domain, the predetermined transmission timing candidate set or specified in advance is used. DS is transmitted. Alternatively, when a terminal apparatus recognizes a transmission burst and the transmission burst and a transmission timing candidate of a predetermined DS overlap, the terminal apparatus transmits a DS at the transmission timing candidate of the predetermined DS. Assume that no DS is transmitted in other DS transmission timing candidates.

  The predetermined DS transmission timing candidates are, for example, the first DS transmission timing candidates among the DS transmission timing candidates that overlap the transmission burst among all the DS transmission timing candidates. The predetermined DS transmission timing candidates are, for example, DS transmission timing candidates specified in the upper layer among the DS transmission timing candidates that overlap the transmission burst.

  Even when a transmission burst cannot be detected, if a DS can be detected, it may be assumed that the DS is not transmitted in a transmission timing candidate after the DS.

That is, when the DS setting in the LAA cell is set, the PDSCH is not arranged in the resource element assumed by the terminal device to be used for transmission of the following signals included in the DS. The predetermined downlink subframe and the predetermined special subframe are the first subframes of subframes indicated by the higher layer and overlapped with the transmission burst.
(1) CRS of antenna port 0 in DwPTS of a predetermined downlink subframe and a predetermined special subframe within the DMTC period.
(2) A first synchronization signal in DwPTS of a predetermined downlink subframe and a predetermined special subframe within the DMTC period.
(3) A second synchronization signal in the DwPTS of a predetermined downlink subframe and a predetermined special subframe within the DMTC period.
(4) Non-zero power CSI-RS of zero or more subframes within the DMTC period. The non-zero power CSI-RS that is part of the DS is set in the DS configuration.

  The PDSCH is a CRS antenna port other than the CRS antenna port 0 in the DwPTS of the predetermined downlink subframe and the predetermined special subframe in the DMTC period (that is, the antenna ports 1, 2, or 3). ) May not be arranged in the resource element used for transmission. Whether or not to place the resource element is set in the upper layer (DS setting).

  The PDSCH may not be arranged in the resource element used for transmission of the third synchronization signal in the DwPTS of the predetermined downlink subframe and the predetermined special subframe in the DMTC period. Whether or not to place the resource element is set in the upper layer (DS setting).

  An example of the assumption of PDSCH mapping in a subframe including DS transmission timing candidates will be described. Whether PDSCH and DS are multiplexed using information on the field of PDSCH RE Mapping and Quasi-Co-Location indicator (PDSCH RE Mapping and Quasi-Co-Location indicator), which is one of the fields in the DCI format. Can be instructed. Specifically, when the field information is “00”, it recognizes that the PDSCH and the DS are not multiplexed, and decodes the PDSCH. When the field information is “01”, the PDSCH and the second channel are decoded. It recognizes that it is multiplexed with the DS set by the parameter set of 1 and decodes the PDSCH. If the information in the field is “10”, it is multiplexed with the DS set by the PDSCH and the second parameter set. When the field information is “11”, the PDSCH is decoded by recognizing that it is multiplexed with the PDSCH and the DS set by the third parameter set. The parameter set includes information regarding the number of CRS ports, information regarding zero power CSI-RS, information regarding arrangement of synchronization signals, and the like.

  According to the above example, the terminal device can efficiently receive DS and PDSCH simultaneously in a predetermined subframe in the LAA cell.

  However, depending on the arrangement of the synchronization signal, there may be a case where the synchronization signal and a specific PDSCH and / or EPDCCH cannot be simultaneously arranged in a predetermined resource block of a predetermined subframe. In that case, the terminal device does not expect to receive a specific PDSCH and / or EPDCCH. In that case, the base station apparatus does not transmit a specific PDSCH and / or EPDCCH. Hereinafter, a case where the synchronization signal and a specific PDSCH and / or EPDCCH cannot be arranged at the same time will be described.

  The primary synchronization signal and the secondary synchronization signal are arranged in OFDM symbols (that is, the sixth and seventh OFDM symbols) in which URS or DMRS is arranged. Therefore, the primary synchronization signal, the secondary synchronization signal, and the URS or DMRS cannot be arranged at the same position. In addition, a specific PDSCH that performs reception processing using the URS cannot be arranged. Furthermore, an EPDCCH that performs reception processing using the DMRS cannot be arranged.

  That is, in a given subframe, when two PRBs overlap in frequency with the transmission of the primary synchronization signal or the secondary synchronization signal, one of the PRBs is arranged with a VRB (virtual resource block) pair. The PRB does not expect to receive PDSCH resource blocks transmitted on antenna ports 5, 7, 8, 9, 10, 11, 12, 13, or 14. Further, in a predetermined subframe, when a PRB pair in which ECCE related to an EPDCCH candidate is arranged overlaps with a frequency of transmission of a primary synchronization signal or a secondary synchronization signal, the terminal apparatus monitors that EPDCCH candidate. Do not expect.

  Similarly, also in the first or second synchronization signal, when the URS or DMRS is arranged in the OFDM symbol, the first or second synchronization signal and the URS or DMRS should be arranged at the same position. I can't. In addition, a specific PDSCH that performs reception processing using the URS cannot be arranged. Furthermore, an EPDCCH that performs reception processing using the DMRS cannot be arranged.

  That is, when the second DS is set for the serving cell, and when the first synchronization signal or the second synchronization signal is arranged in the sixth or seventh OFDM symbol, When two PRBs overlap in frequency with the transmission of the first synchronization signal or the second synchronization signal in one of the PRBs in the subframe, the terminal device has a VRB (virtual resource block) pair arranged therein. The PRB does not expect to receive PDSCH resource blocks transmitted on antenna ports 5, 7, 8, 9, 10, 11, 12, 13, or 14. Further, in a predetermined subframe, when the PRB pair in which the ECCE related to the EPDCCH candidate is arranged overlaps with the transmission of the first synchronization signal or the second synchronization signal in frequency, the terminal apparatus selects the EPDCCH candidate. Do not expect to monitor.

  Similarly, in the third synchronization signal, when the URS or DMRS is arranged in the OFDM symbol, the third synchronization signal and the URS or DMRS cannot be arranged in the same position. In addition, a specific PDSCH that performs reception processing using the URS cannot be arranged. Furthermore, an EPDCCH that performs reception processing using the DMRS cannot be arranged.

  That is, when the second DS is set for the serving cell, and when the third synchronization signal is arranged in the sixth or seventh OFDM symbol, and in a predetermined subframe, two When the PRB overlaps with the transmission of the third synchronization signal on one of the frequencies, the terminal device uses the antenna ports 5, 7, 8, 9 in the PRB in which a VRB (virtual resource block) pair is arranged. Do not expect to receive PDSCH resource blocks transmitted at 10, 11, 12, 13, or 14. Also, in a predetermined subframe, when the PRB pair in which the ECCE related to the EPDCCH candidate is arranged overlaps with the transmission of the third synchronization signal on the frequency, the terminal device does not expect to monitor the EPDCCH candidate .

  Further, in the CSI reference resource serving as a reference for calculating the CSI, the terminal device assumes that the resource element is not used by the first, second, and / or third synchronization signal, and the CQI index, PMI, and The RI is derived.

  In other words, a part of the contents described in the present embodiment is as follows.

  The terminal device includes a receiving unit that acquires time and frequency synchronization with the cell based on the primary synchronization signal, the first secondary synchronization signal, and the second secondary synchronization signal. When the setting related to the second secondary synchronization signal is not made for the cell, synchronization is acquired based on the primary synchronization signal and the first secondary synchronization signal, and the setting related to the second secondary synchronization signal is made for the cell. In the case where the first secondary synchronization signal is synchronized, the synchronization is acquired based on the primary synchronization signal and the second secondary synchronization signal, and the plurality of first resource elements to which the second secondary synchronization signal is mapped have the first secondary synchronization signal Different from the plurality of second resource elements to be mapped.

  In addition, the subframe period in which the second secondary synchronization signal is arranged is longer than the subframe period in which the primary synchronization signal or the first secondary synchronization signal is arranged.

  In addition, the OFDM symbol in which the second secondary synchronization signal is arranged is different from the OFDM symbol in which the primary synchronization signal or the first secondary synchronization signal is arranged.

  Moreover, the setting regarding the second secondary synchronization signal is made for the LAA cell, and the setting for the second secondary synchronization signal is not made for the cells other than the LAA cell.

  The plurality of first resource elements to which the second secondary synchronization signal is mapped are based on the cell identifier.

  In addition, a part of the contents described in the present embodiment is as follows.

  The terminal device includes a receiving unit that receives PDSCH, a detecting unit that detects a DS including a synchronization signal, and an upper layer processing unit that performs settings related to the DS. When the setting related to the DS is performed, the PDSCH is not arranged in the resource element assumed to be used for transmission of the synchronization signal in the instructed subframe.

  Further, the instructed subframe is all downlink subframes or special subframes in the DMTC section.

  The designated subframe is designated by an upper layer parameter in a bitmap format of 6 bits or less.

  Further, the designated subframe is designated by DCI.

  Further, the designated subframe is a subframe in which the DMTC interval and the PDSCH transmission burst overlap.

  When one or more settings (LAA-Config) necessary for LAA communication are made in the terminal device 1 for the predetermined serving cell, the predetermined serving cell may be regarded as an LAA cell. The settings necessary for LAA communication are, for example, a parameter related to a reservation signal, a parameter related to RSSI measurement, and a parameter related to the setting of the second DS.

  In addition, when the center frequency information (EARFCN value) corresponding to the LAA band is set for the predetermined serving cell in the terminal device 1, the cell of that frequency may be regarded as the LAA cell. The LAA band (LAA operating band) is defined by, for example, a band whose band number is any of 252 to 255, a band that is neither a TDD band nor an FDD band, a band defined by a 5 GHz band, or a bandwidth of 20 MHz. A band that satisfies one or more of the characteristics of a band.

  The predetermined frequency is preferably a frequency used in the LAA cell. Note that the predetermined frequency is preferably the frequency of the cell to which the DS is transmitted based on the LBT. The predetermined frequency is preferably a frequency of a cell operated in an unlicensed band. The predetermined frequency is preferably an operating band frequency corresponding to a predetermined index of the operating band. The predetermined frequency is preferably an operating band frequency corresponding to the LAA operating band index. The predetermined frequency is preferably an operating band corresponding to a predetermined index of an operating band (E-UTRA operating band). For example, the operating bands are preferably managed in a table, and each operating band managed in the table is given a corresponding index. The index is associated with a corresponding uplink operating band, downlink operating band, and duplex mode. The uplink operating band is an operating band used for reception at the base station apparatus and transmission at the terminal apparatus, and the downlink operating band is an operating band used for transmission at the base station apparatus and reception at the terminal apparatus. The uplink operating band and the downlink operating band are preferably provided with a lower limit frequency and an upper limit frequency (corresponding frequency band), respectively. The duplex mode is preferably given by TDD or FDD. Note that the duplex mode in the LAA cell may be other than TDD and FDD. For example, the duplex mode in the LAA cell may be a transmission burst described later (including at least a downlink burst, whether or not an uplink burst is included).

  For example, when the operating band is managed in a table, the operating band corresponding to the index “1” to the index “44” is preferably a licensed band (a band not LAA), and the index “252” to the index “255”. The corresponding operating band is preferably an unlicensed band (LAA band). Note that it is preferable that the uplink operating band is not applied to the index “252” (n / a, not applicable), 5150 MHz to 5250 Hz is applied to the downlink operating band, and FDD is applied to the duplex mode. In addition, it is preferable that an uplink operating band is reserved (reserved for future use), a downlink operating band is reserved for index “253”, and FDD is applied to the duplex mode. In addition, it is preferable that an uplink operating band is reserved (reserved for future use), a downlink operating band is reserved for index “254”, and FDD is applied to the duplex mode. In addition, it is preferable that the uplink operating band is not applied to the index “255” (n / a, not applicable), 5725 MHz to 5850 Hz is applied to the downlink operating band, and FDD is applied to the duplex mode. Note that 5150 MHz-5250 Hz and 5725 MHz-5850 Hz are preferably unlicensed bands (LAA bands). That is, the predetermined frequency is preferably an operating band corresponding to the index “252” to the index “255”.

  Moreover, although each said embodiment demonstrated using the terms primary cell and PS cell, it is not necessary to use these terms necessarily. For example, the primary cell in each of the above embodiments can also be called a master cell, and the PS cell in each of the above embodiments can also be called a primary cell.

  A program that operates in the base station device 2 and the terminal device 1 according to the present invention is a program that controls a CPU (Central Processing Unit) or the like (a program that causes a computer to function) so as to realize the functions of the above-described embodiments according to the present invention. ). Information handled by these devices is temporarily accumulated in RAM (Random Access Memory) during the processing, and then stored in various ROMs such as Flash ROM (Read Only Memory) and HDD (Hard Disk Drive). Reading, correction, and writing are performed by the CPU as necessary.

  Note that the terminal device 1, the base station device 2-1, or a part of the base station device 2-2 in the above-described embodiment may be realized by a computer. In that case, the program for realizing the control function may be recorded on a computer-readable recording medium, and the program recorded on the recording medium may be read by the computer system and executed.

  The “computer system” here is a computer system built in the terminal device 1, the base station device 2-1, or the base station device 2-2, and includes hardware such as an OS and peripheral devices. Shall be. The “computer-readable recording medium” refers to a storage device such as a flexible medium, a magneto-optical disk, a portable medium such as a ROM and a CD-ROM, and a hard disk incorporated in a computer system.

  Furthermore, the “computer-readable recording medium” is a medium that dynamically holds a program for a short time, such as a communication line when transmitting a program via a network such as the Internet or a communication line such as a telephone line, In such a case, a volatile memory inside a computer system serving as a server or a client may be included and a program that holds a program for a certain period of time. The program may be a program for realizing a part of the functions described above, and may be a program capable of realizing the functions described above in combination with a program already recorded in a computer system.

  In addition, the base station device 2-1 or the base station device 2-2 in the above-described embodiment can also be realized as an aggregate (device group) composed of a plurality of devices. Each of the devices constituting the device group may include a part or all of each function or each functional block of the base station device 2-1 or the base station device 2-2 according to the above-described embodiment. As a device group, the base station device 2-1 or the base station device 2-2 may have a single function or function block. The terminal device 1 according to the above-described embodiment can also communicate with the base station device as an aggregate.

  Further, the base station apparatus 2-1 or the base station apparatus 2-2 in the above-described embodiment may be an EUTRAN (Evolved Universal Terrestrial Radio Access Network). In addition, the base station device 2-1 or the base station device 2-2 in the above-described embodiment may have a part or all of the functions of the upper node for the eNodeB.

  In addition, part or all of the terminal device 1, the base station device 2-1, or the base station device 2-2 in the above-described embodiment may be realized as an LSI that is typically an integrated circuit, or a chip set. It may be realized as. Each functional block of the terminal device 1, the base station device 2-1, or the base station device 2-2 may be individually chipped, or a part or all of them may be integrated into a chip. Further, the method of circuit integration is not limited to LSI, and may be realized by a dedicated circuit or a general-purpose processor. In addition, when an integrated circuit technology that replaces LSI appears due to progress in semiconductor technology, an integrated circuit based on the technology can also be used.

  In the above-described embodiment, the cellular mobile station device is described as an example of the terminal device or the communication device. However, the present invention is not limited to this, but is a stationary type that is installed indoors or outdoors, or non-movable. It can also be applied to terminal devices or communication devices such as AV devices, kitchen devices, cleaning / washing devices, air conditioning devices, office devices, vending machines, and other daily life devices.

  The embodiment of the present invention has been described in detail with reference to the drawings. However, the specific configuration is not limited to this embodiment, and includes design changes and the like without departing from the gist of the present invention. The present invention can be modified in various ways within the scope of the claims, and embodiments obtained by appropriately combining technical means disclosed in different embodiments are also included in the technical scope of the present invention. It is. Moreover, it is the element described in each said embodiment, and the structure which substituted the element which has the same effect is also contained.

501 Upper layer 502 Control unit 503 Codeword generation unit 504 Downlink subframe generation unit 505 Downlink reference signal generation unit 506 OFDM signal transmission unit 507 Transmission antenna 508 Reception antenna 509 SC-FDMA signal reception unit 510 Uplink subframe processing unit 511 Uplink control information extraction unit 601 Reception antenna 602 OFDM signal reception unit 603 Downlink subframe processing unit 604 Downlink reference signal extraction unit 605 Transport block extraction unit 606, 1006 Control unit 607, 1007 Upper layer 608 Channel state measurement unit 609, 1009 Uplink subframe generation unit 610 Uplink control information generation units 611, 612, 1011 SC-FDMA signal transmission units 613, 614, 1013

Claims (12)

A terminal device,
Based on the primary synchronization signal, the first secondary synchronization signal, and the second secondary synchronization signal, a receiving unit that acquires time and frequency synchronization with the cell,
When the second secondary synchronization signal is not set for the cell, the synchronization is acquired based on the primary synchronization signal and the first secondary synchronization signal,
When the second secondary synchronization signal is set for the cell, the synchronization is acquired based on the primary synchronization signal and the second secondary synchronization signal,
The plurality of first resource elements to which the second secondary synchronization signal is mapped are different from the plurality of second resource elements to which the first secondary synchronization signal is mapped. The terminal device according to claim 1, wherein a subframe period in which the second secondary synchronization signal is arranged is longer than a subframe period in which the primary synchronization signal or the first secondary synchronization signal is arranged. The terminal apparatus according to claim 1, wherein the OFDM symbol in which the second secondary synchronization signal is arranged is different from the OFDM symbol in which the primary synchronization signal or the first secondary synchronization signal is arranged. Settings for the second secondary synchronization signal are made for the LAA cell,
The terminal device according to claim 1, wherein the second secondary synchronization signal is not set for a cell other than the LAA cell. The terminal device according to claim 1, wherein the plurality of first resource elements to which the second secondary synchronization signal is mapped are based on a cell identifier. A base station device that communicates with a terminal device,
A transmission unit for transmitting the primary synchronization signal, the first secondary synchronization signal, and the second secondary synchronization signal;
If the terminal device is not set for the cell with respect to the second secondary synchronization signal, the primary synchronization signal and the first secondary synchronization signal are transmitted,
When the terminal device is configured for the second secondary synchronization signal for the cell, the primary synchronization signal and the second secondary synchronization signal are transmitted,
The plurality of first resource elements to which the second secondary synchronization signal is mapped are different from the plurality of second resource elements to which the first secondary synchronization signal is mapped. The base station apparatus according to claim 6, wherein a subframe cycle in which the second secondary synchronization signal is arranged is longer than a subframe cycle in which the primary synchronization signal or the first secondary synchronization signal is arranged. The base station apparatus according to claim 6, wherein the OFDM symbol in which the second secondary synchronization signal is arranged is different from the OFDM symbol in which the primary synchronization signal or the first secondary synchronization signal is arranged. The terminal device is configured for the second secondary synchronization signal for the LAA cell,
The base station apparatus of Claim 6. The setting regarding a said 2nd secondary synchronizing signal is not performed to the said terminal device with respect to cells other than the said LAA cell. The base station apparatus according to claim 6, wherein the plurality of first resource elements to which the second secondary synchronization signal is mapped are based on a cell identifier. A communication method used for a terminal device,
Obtaining time and frequency synchronization with the cell based on the primary synchronization signal, the first secondary synchronization signal, and the second secondary synchronization signal;
When the second secondary synchronization signal is not set for the cell, the synchronization is acquired based on the primary synchronization signal and the first secondary synchronization signal,
When the second secondary synchronization signal is set for the cell, the synchronization is acquired based on the primary synchronization signal and the second secondary synchronization signal,
The plurality of first resource elements to which the second secondary synchronization signal is mapped are different from the plurality of second resource elements to which the first secondary synchronization signal is mapped. A communication method used in a base station device that communicates with a terminal device,
Transmitting a primary synchronization signal, a first secondary synchronization signal, and a second secondary synchronization signal;
If the terminal device is not set for the cell with respect to the second secondary synchronization signal, the primary synchronization signal and the first secondary synchronization signal are transmitted,
When the terminal device is configured for the second secondary synchronization signal for the cell, the primary synchronization signal and the second secondary synchronization signal are transmitted,
The plurality of first resource elements to which the second secondary synchronization signal is mapped are different from the plurality of second resource elements to which the first secondary synchronization signal is mapped.

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