JP2014068299A - Terminal device, communication method, and integrated circuit - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a terminal device, communication method, and integrated circuit capable of efficiently performing communication by transmitting/receiving downlink reference signals on the basis of assumption related to quasi co-location of an antenna port.SOLUTION: A terminal device assumes that a first antenna port and a second antenna port are not quasi co-located, in a case where a first transmission mode is set and a first downlink control information format is detected. In a case where the first transmission mode is set and a second downlink control information format is detected; the terminal device assumes that the second antenna port and the first antenna port are quasi co-located, only when a channel state information reference signal transmitted by using the second antenna port is mapped to a resource designated by using control information included in the second downlink control information format.

Description

  The present invention relates to a terminal device, a communication method, and an integrated circuit.

  3GPP (Third Generation Partnership Project) in due LTE (Long Term Evolution), in the LTE-A (LTE-Advanced) and wireless communication systems, such as the IEEE WiMAX due to the (The Institute of Electrical and Electronics engineers) (Worldwide Interoperability for Microwave Access) is Each of the base station and the terminal is provided with one or a plurality of transmission / reception antennas, and high-speed data transmission can be realized by using, for example, a MIMO (Multiple Input Multiple Output) technique.

  Here, in a wireless communication system, it is considered that a plurality of terminals support MU-MIMO (Multiple User MIMO) that performs spatial multiplexing using the same frequency and time resources. In addition, it has been studied to support a CoMP (Cooperative Multipoint) transmission scheme in which a plurality of base stations cooperate with each other to perform interference coordination. For example, a wireless communication system in a heterogeneous network deployment (HetNet; Heterogeneous Network deployment) such as a macro base station with a wide coverage and an RRH (Remote Radio Head) with a narrower coverage than the macro base station is being studied.

  In such a wireless communication system, an antenna port in which a base station and a terminal are apparently arranged at the same place (also referred to as quasi co-located). It is proposed to transmit and receive downlink reference signals (DRS; Downlink Reference Signals) (Non-patent Document 1).

3GPP TSG RAN WG1 meeting # 70 R1-123589, August 13th-17th, 2012. Remaining issues on quasi-located antenna ports;

  However, in the wireless communication system as described above, there is no description regarding a specific procedure when a terminal receives a downlink reference signal based on an assumption regarding a quasi-co-location of an antenna port. It was.

  The present invention has been made in view of the above problems, and an object thereof is a terminal device capable of efficiently transmitting and receiving a downlink reference signal based on assumptions regarding the azimuth location of an antenna port. A communication method and an integrated circuit are provided.

  (1) In order to achieve the above object, the present invention takes the following measures. That is, the terminal device in the present invention is a terminal device that communicates with the base station device, and when the first transmission mode is set and the first downlink control information format is detected, at least the physical downlink A first antenna port used for transmitting a user equipment specific reference signal related to a link shared channel and a second antenna port used for transmitting a channel state information reference signal are quasi co-located. If the first transmission mode is set and the second downlink control information format is detected, the channel state transmitted using the second antenna port is assumed. The information reference signal is indicated by using the control information included in the second downlink control information format. Only when mapped to over scan, the second antenna ports, is characterized in that assume are the first antenna port and quasi roller Kay Incorporated.

  (2) Further, when the first transmission mode is set and the first downlink control information format is detected in the communication method of the terminal device communicating with the base station device, at least the physical downlink A first antenna port used for transmitting a user equipment specific reference signal related to a shared channel and a second antenna port used for transmitting a channel state information reference signal are quasi-co-located. ), The channel state information transmitted using the second antenna port when the first transmission mode is set and the second downlink control information format is detected. A reference signal is mapped to the indicated resource using the control information included in the second downlink control information format Only when it said second antenna port, and characterized in that assumed to be the first antenna port and quasi roller Kay Incorporated.

  (3) In addition, when the first transmission mode is set and the first downlink control information format is detected in the integrated circuit mounted on the terminal device communicating with the base station device, at least, A first antenna port used for transmission of a user equipment specific reference signal related to a physical downlink shared channel and a second antenna port used for transmission of a channel state information reference signal are quasi-collocated. When the first transmission mode is set and the second downlink control information format is detected, the function is assumed to be not co-located), and is transmitted using the second antenna port. The channel state information reference signal is indicated using control information included in the second downlink control information format. Only when that is mapped to the resource, the second antenna ports, is characterized in a function of assumed to be the first antenna port and quasi roller silicic Incorporated, that exert to the terminal device.

  ADVANTAGE OF THE INVENTION According to this invention, a terminal can transmit / receive a downlink reference signal and can communicate efficiently based on assumption regarding the quasi-colocation of an antenna port.

It is a schematic block diagram which shows the structure of the base station which concerns on this embodiment. It is a schematic block diagram which shows the structure of the terminal which concerns on this embodiment. It is the schematic which shows an example of the radio | wireless communications system which concerns on this embodiment. It is a figure which shows an example of a mapping of a physical downlink channel and a downlink reference signal. It is a figure which shows an example of the mapping of a physical downlink channel. It is a figure for demonstrating this embodiment. It is another figure for demonstrating this embodiment. It is a figure which shows an example of the processing flow which concerns on this embodiment.

  Hereinafter, embodiments of the present invention will be described. The wireless communication system in the embodiment of the present invention includes a base station device (base station, transmission device, cell, serving cell, transmission station, transmission point (TP), transmission antenna group, transmission antenna port group, eNodeB, and eNB). As a primary base station (macro base station, first base station, first communication device, transmission point 1 (TP1), transmission base point, serving base station, anchor base station, primary cell) And secondary base stations (RRH, pico base station, femto base station, Home eNodeB, second base station device, second communication device, transmission point 2 (Transmission point 2), coordinated base station group, coordinated base station Set, cooperative base station, secondary cell, LPN (L Equipped with a w Power Node) also is referred to).

  It is also referred to as a mobile station device (terminal, terminal device, mobile terminal, receiving device, receiving point, receiving terminal, third communication device, receiving antenna group, receiving antenna port group, user equipment (UE)). ).

  Here, for example, the heterogeneous network arrangement may be applied to the primary base station and the secondary base station, and a part or all of the coverage of the secondary base station may be included in the coverage of the primary base station. The secondary base station may be a plurality of secondary base stations.

  FIG. 1 is a schematic block diagram showing the configuration of the base station according to this embodiment. Here, the base station 100 shown in FIG. 1 includes a primary base station and a secondary base station. The base station 100 includes a data control unit 101, a transmission data modulation unit 102, a radio unit 103, a scheduling unit 104, a channel estimation unit 105, a reception data demodulation unit 106, a data extraction unit 107, and an upper layer 108. And an antenna 109. Radio section 103, scheduling section 104, channel estimation section 105, reception data demodulation section 106, data extraction section 107, upper layer 108 and antenna 109 constitute a reception section. Further, the data control unit 101, the transmission data modulation unit 102, the radio unit 103, the scheduling unit 104, the upper layer 108, and the antenna 109 constitute a transmission unit. Here, each part which comprises the base station 100 is also called a unit.

  The data control unit 101 receives a transport channel from the scheduling unit 104. The data control unit 101 maps signals generated in the transport channel and the physical layer to the physical channel based on scheduling information input from the scheduling unit 104. Each mapped data is output to transmission data modulation section 102.

  The transmission data modulation unit 102 modulates / encodes transmission data. The transmission data modulation unit 102 modulates / encodes the data input from the data control unit 101 based on scheduling information from the scheduling unit 104, serial / parallel conversion of the input signal, IFFT (Inverse Fast Fourier Transform). Conversion: Performs signal processing such as inverse phase Fourier transform (CP) processing and CP (cyclic prefix) insertion, generates transmission data, and outputs the transmission data to the radio section 103.

  Radio section 103 up-converts the transmission data input from transmission data modulation section 102 to a radio frequency to generate a radio signal, and transmits the radio signal to a terminal via antenna 109. Radio section 103 receives a radio signal received from the terminal via antenna 109, down-converts it to a baseband signal, and outputs received data to channel estimation section 105 and received data demodulation section 106.

  The scheduling unit 104 performs mapping between logical channels and transport channels, downlink and uplink scheduling, and the like. Since the scheduling unit 104 controls the processing units of each physical layer in an integrated manner, the scheduling unit 104, the antenna 109, the radio unit 103, the channel estimation unit 105, the reception data demodulation unit 106, the data control unit 101, the transmission data modulation An interface between the unit 102 and the data extraction unit 107 exists.

  In downlink scheduling, the scheduling unit 104 generates transmission control and scheduling information in the transport channel and physical channel based on uplink control information received from the terminal, scheduling information input from the higher layer 108, and the like. To do. The scheduling information used for downlink scheduling is output to the data control unit 101.

  Further, in uplink scheduling, scheduling section 104 generates scheduling information based on the uplink channel state output from channel estimation section 105, scheduling information input from higher layer 108, and the like. Scheduling information used for uplink scheduling is output to the data control unit 101.

  In addition, the scheduling unit 104 maps the downlink logical channel input from the higher layer 108 to the transport channel, and outputs it to the data control unit 101. Also, the scheduling unit 104 processes the uplink transport channel and control data input from the data extraction unit 107 as necessary, maps them to the uplink logical channel, and outputs them to the upper layer 108.

  The channel estimation unit 105 estimates an uplink channel state from an uplink reference signal (for example, a demodulation reference signal) and demodulates the signal transmitted on the uplink, and outputs it to the reception data demodulation unit 106 . Further, in order to perform uplink scheduling, an uplink channel state is estimated from an uplink reference signal (for example, a sounding reference signal), and is output to the scheduling section 104.

  Received data demodulation section 106 demodulates received data. Based on the uplink channel state estimation result input from the channel estimation unit 105, the reception data demodulation unit 106 performs DFT conversion, subcarrier mapping, IFFT conversion, etc. on the modulation data input from the radio unit 103. Signal processing is performed, demodulation processing is performed, and the data is output to the data extraction unit 107.

  The data extraction unit 107 confirms whether the received data input from the received data demodulation unit 106 is correct and outputs a confirmation result (eg, ACK or NACK) to the scheduling unit 104. The data extraction unit 107 separates the data input from the reception data demodulation unit 106 into a transport channel and physical layer control data, and outputs the separated data to the scheduling unit 104.

  The upper layer 108 performs processing of a radio resource control (RRC) layer and processing of a MAC (Media Access Control) layer. The upper layer 108 integrates and controls the processing units of the lower layer, so the upper layer 108, the scheduling unit 104, the antenna 109, the radio unit 103, the channel estimation unit 105, the received data demodulation unit 106, the data control unit 101, There is an interface between the transmission data modulation unit 102 and the data extraction unit 107.

  FIG. 2 is a schematic block diagram showing the configuration of the terminal according to the present embodiment. The terminal 200 includes a data control unit 201, a transmission data modulation unit 202, a radio unit 203, a scheduling unit 204, a channel estimation unit 205, a reception data demodulation unit 206, a data extraction unit 207, an upper layer 208, And an antenna 209. The data control unit 201, transmission data modulation unit 202, radio unit 203, scheduling unit 204, upper layer 208, and antenna 209 constitute a transmission unit. The radio unit 203, scheduling unit 204, channel estimation unit 205, reception data demodulation unit 206, data extraction unit 207, higher layer 208, and antenna 209 constitute a reception unit. Here, each part which comprises the terminal 200 is also called a unit.

  The data control unit 201 receives a transport channel from the scheduling unit 204. Further, the data control unit 201 maps signals generated in the transport channel and the physical layer to the physical channel based on the scheduling information input from the scheduling unit 204. Each mapped data is output to transmission data modulation section 202.

  The transmission data modulation unit 202 modulates / encodes transmission data. Transmission data modulation section 202 performs signal processing such as modulation / coding, input signal serial / parallel conversion, IFFT processing, CP insertion on the data input from data control section 201 to generate transmission data. To the wireless unit 203.

  Radio section 203 up-converts transmission data input from transmission data modulation section 202 to a radio frequency, generates a radio signal, and transmits the radio signal to a base station via antenna 209. Radio section 203 receives a radio signal received from the base station via antenna 209, down-converts it to a baseband signal, and outputs the received data to channel estimation section 205 and received data demodulation section 206. .

  The scheduling unit 204 performs mapping between logical channels and transport channels, downlink and uplink scheduling, and the like. Since the scheduling unit 204 controls the processing units of each physical layer in an integrated manner, the scheduling unit 204, the antenna 209, the data control unit 201, the transmission data modulation unit 202, the channel estimation unit 205, the reception data demodulation unit 206, the data There is an interface between the extraction unit 207 and the wireless unit 203.

  In addition, the scheduling unit 204 performs reception control and generation of scheduling information on the transport channel and the physical channel based on downlink control information received from the base station, scheduling information input from the higher layer 208, and the like. The scheduling information used for downlink scheduling is output to the data control unit 201.

  Also, the scheduling unit 204 maps the uplink logical channel input from the upper layer 208 to the transport channel based on downlink control information received from the base station, scheduling information input from the upper layer 208, and the like. Scheduling information for generation and scheduling information used for uplink scheduling is generated. The scheduling information is output to the data control unit 201.

  Also, the scheduling unit 204 maps the uplink logical channel input from the higher layer 208 to the transport channel, and outputs it to the data control unit 201. The scheduling unit 204 also includes channel state information input from the channel estimation unit 205 and CRC (Cyclic Redundancy Check) parity bits (also simply referred to as CRC) input from the data extraction unit 207. The confirmation result is also output to the data control unit 201.

  In addition, the scheduling unit 204 assumes that each antenna port used for transmission of the downlink reference signal is quasi-correlated and outputs the result to the channel estimation unit 205.

  The channel estimation unit 205 estimates the downlink channel state from the downlink reference signal and demodulates the signal transmitted on the downlink, and outputs it to the reception data demodulation unit 206. Received data demodulation section 206 demodulates the received data input from radio section 203 and outputs the demodulated data to data extraction section 207.

  Further, the channel estimation unit 205 demodulates the downlink reference signal based on the assumption regarding the quasi-colocation from the scheduling unit 204.

  The data extraction unit 207 confirms the correctness of the reception data input from the reception data demodulation unit 206 and outputs a confirmation result (for example, ACK or NACK) to the scheduling unit 204. Further, the data extraction unit 207 separates the reception data input from the reception data demodulation unit 206 into transport channel and physical layer control data, and outputs the data to the scheduling unit 204.

  The upper layer 208 performs processing of the radio resource control layer and processing of the MAC layer. The upper layer 208 integrates and controls the processing units of the lower layer, so that the upper layer 208, the scheduling unit 204, the antenna 209, the data control unit 201, the transmission data modulation unit 202, the channel estimation unit 205, the reception data demodulation unit 206, an interface between the data extraction unit 207 and the wireless unit 203 exists.

  FIG. 3 is a schematic diagram illustrating an example of a wireless communication system according to the present embodiment. In FIG. 3, for example, the terminal 303 can perform single cell communication with the primary base station 301 or the secondary base station 302. In addition, the terminal 303 can perform multicell communication with the primary base station 301 and / or the secondary base station 302.

  Here, the single cell communication indicates that a single base station transmits downlink information (downlink signal) to a terminal. For example, the terminal 303 can receive downlink information transmitted from the primary base station 301 on the downlink 304 in a certain subframe. Also, the terminal 303 can receive downlink information transmitted from the secondary base station 302 via the downlink 305 in another certain subframe.

  Multi-cell communication indicates that a plurality of base stations cooperate with each other to transmit downlink information to a terminal. For example, the terminal 303 receives downlink information transmitted from the primary base station 301 on the downlink 304 and downlink information transmitted from the secondary base station 302 on the downlink 305 in the same subframe. Can do.

  Further, for example, the terminal 303 transmits downlink information transmitted from the primary base station 301 on the downlink 304 or downlink transmitted from the secondary base station 302 on the downlink 305 as in dynamic point selection described later. Link information can be received in the same subframe. In multi-cell communication in which dynamic point selection is performed, the terminal 303 can perform reception processing without recognizing which base station (transmission point) is transmitting downlink information.

  For example, multi-cell communication includes a CoMP transmission scheme. More specifically, joint transmission (JT: Joint processing) in which the same downlink information is transmitted from a plurality of base stations is included. Also included is dynamic point selection (DPS) in which base stations that transmit downlink information are dynamically switched. Further, coordinated beamforming (CB) that reduces interference by performing beamforming in cooperation between base stations is included. Also, coordinated scheduling (CS) that reduces interference by performing coordinated scheduling between base stations is included.

  In addition, for example, communication between base stations (for example, exchange of control information for performing multi-cell communication or single-cell communication) uses a wired line such as an optical fiber or a wireless line such as a relay.

  Here, different physical layer cell identities (PCI; also referred to as physical layer cell identities, physical layer cell identifiers) may be set for the primary base station 301 and the secondary base station 302. Further, the same physical layer cell identity may be set for all or part of the primary base station 301 and the secondary base station 302.

  For example, the UE can detect physical layer cell identities using synchronization signals (Synchronization signals). Also, the terminal can acquire the physical layer cell identity from information included in an upper layer signal (for example, a band over command) transmitted by the base station.

  Here, the downlink information includes downlink data (downlink shared channel (DL-SCH)). Also, the downlink information includes downlink control information (DCI; Downlink Control Information).

  Here, DL-SCH is a transport channel. Here, a channel used in a medium access control (MAC) layer is referred to as a transport channel. The unit of the transport channel used in the MAC layer is also referred to as a transport block (Transport Block).

  Also, the DL-SCH is mapped to a physical downlink shared channel (PDSCH; Physical Downlink Shared Channel). That is, PDSCH is used for transmitting downlink data.

  Moreover, downlink control information is mapped by the physical downlink control channel (PDCCH; Physical Downlink Control Channel). That is, PDCCH is used for transmitting downlink control information.

  Also, the downlink control information may be mapped to an enhanced physical downlink control channel (E-PDCCH; Enhanced Physical Downlink Control Channel, enhanced PDCCH). That is, E-PDCCH is used for transmitting downlink control information.

  Here, when transmitting downlink information to a terminal, the base station multiplexes and transmits a downlink reference signal (DRS; Downlink Reference Signals) that is a known signal between the base station and the terminal. Here, the downlink reference signal is a physical signal.

  For example, at least three different types of downlink reference signals are defined as downlink reference signals. Here, antenna ports to which different numbers are assigned are defined for the transmissions of the three types of downlink reference signals. That is, different types of downlink reference signals are transmitted using different antenna ports.

  Here, for example, an antenna port means “a channel (for example, a propagation path) on which a symbol (for example, a physical signal, a downlink reference signal) on an antenna port is carried is another symbol on the same antenna port. It is defined as “inferred from the channel being carried”.

  For example, a user equipment specific reference signal related to PDSCH (also referred to as a user equipment-specific reference associated PDSCH, a terminal-specific reference signal related to PDSCH) is defined as a downlink reference signal. Here, the user apparatus specific reference signal is also referred to as a demodulation reference signal associated with PDSCH (Demodulation Reference Signal associated with PDSCH, PDSCH DM-RS).

  For example, PDSCH DM-RS is used for a terminal to perform propagation path correction for E-PDCCH. Moreover, PDSCH DM-RS is used in order that a terminal may perform the propagation path correction | amendment with respect to PDSCH. The PDSCH DM-RS is transmitted targeting a specific terminal. Also, the PDSCH DM-RS is transmitted only in the physical resource block to which the corresponding PDSCH is mapped.

  For example, the PDSCH DM-RS is transmitted through one or more antenna ports of the antenna ports 7 to 14. Hereinafter, the antenna port used for transmission of PDSCH DM-RS is also referred to as a first antenna port.

  Here, in the terminal, each of a plurality of antenna ports used for transmission of PDSCH DM-RSs has a channel characteristic of a long period (also referred to as long term channel properties, large-scale properties) in a certain cell. With regard to, it can be assumed that it has been quatted.

  Here, the antenna port is quasi-collocated, if “two antenna ports are quasi-collocated, the terminal will receive a symbol (eg, a physical signal , Downlink reference signals) may be assumed that the long-term channel characteristics of the channel (eg, propagation path) are inferred from the channel on which the symbol on the other antenna port is carried. Is done.

  That is, for example, the terminal can assume that the channel characteristics of a long period of a channel in which a certain downlink reference signal is carried are inferred from a channel in which another downlink reference signal is carried.

  Here, the long-term channel characteristics include characteristics related to delay spread. The long-term channel characteristics include characteristics related to Doppler spread. The long-term channel characteristics include characteristics related to Doppler shift. The long-term channel characteristics include characteristics related to average gain. The long-term channel characteristics include characteristics related to average delay.

  In addition, a channel state information reference signal (CSI-RS) is defined as a downlink reference signal.

  For example, CSI-RS is used for a terminal to calculate downlink channel state information. Moreover, CSI-RS is transmitted only in the band set by the base station.

  Here, the base station can set the parameter regarding each of several CSI-RSs to a terminal in a certain cell. That is, the base station can perform a plurality of settings of CSI-RS.

  For example, the base station can transmit a parameter related to each of a plurality of CSI-RSs in a dedicated RRC signaling shown below. For example, the base station can transmit a parameter related to each of the three CSI-RSs by including it in the dedicated RRC signaling.

  Here, the parameter regarding CSI-RS is also described as the parameter regarding non-zero power CSI-RS (NZP-CSI-RS; Non-Zero power CSI-RS). That is, for example, the maximum number of non-zero power CSI-RS (non-zero power CSI-RS resources) that can be set for each cell can be three.

  Here, for example, a parameter related to CSI-RS is used to indicate the position of information (for example, resource element may be mapped) to which CSI-RS is mapped to indicate CSI-RS resource. Information used). Further, the parameters related to the CSI-RS include information used for instructing the antenna port number used for CSI-RS transmission.

  Hereinafter, the setting for CSI-RS is also referred to as CSI-RS configuration. That is, CSI-RS configuration is defined by a dedicated RRC signaling.

  In addition, each of the three CSI-RSs (or three CSI-RS resources) set by the base station may be CSI-RS # 1 (or CSI-RS resource # 1), CSI-RS # 2 (or , CSI-RS resource # 2) and CSI-RS # 3 (or CSI-RS resource # 3).

  For example, the configuration of one, two, four, or eight antenna ports is supported for CSI-RS transmission. For example, the CSI-RS is transmitted through one or more antenna ports of the antenna ports 15 to 22. Hereinafter, the antenna port used for CSI-RS transmission is also referred to as a second antenna port.

  Here, for example, each of CSI-RSs in which different parameters are set (for example, CSI-RSs transmitted in each of CSI-RS resource # 1, CSI-RS resource # 2, and CSI-RS resource # 3) is The same antenna port may be used for transmission. Also, for example, each of CSI-RSs related to the same antenna port and different CSI-RS resources may be transmitted at different transmission points.

  Here, the terminal may assume that each of a plurality of antenna ports used for transmission of CSI-RSs is quasi-correlated with respect to channel characteristics over a long period of time within a certain CSI resource. it can. That is, the terminal determines that each of a plurality of antenna ports used for transmission of CSI-RSs mapped to a CSI resource in which a certain parameter is set is quasi-correlated with respect to a long-term channel characteristic. Can be assumed.

  That is, the terminal may not assume that each of a plurality of antenna ports used for transmission of CSI-RSs is quasi-correlated with respect to long-term channel characteristics between different CSI resources. (It can be assumed that it is not quasi-collocated). That is, each of a plurality of antenna ports used for transmission of CSI-RSs mapped to CSI-RS resources configured with different parameters is quasi-collocated with respect to long-term channel characteristics. You can't assume that.

  In addition, a cell-specific reference signal (CRS: Cell-specific Reference Signals, also called cell-specific reference signal) is defined as a downlink reference signal. Here, the cell-specific reference signal is also referred to as a common reference signal (CRS; Common Reference Signals).

  For example, CRS is used for a terminal to synchronize downlink frequency domain and time domain. Also, the CRS is used for the terminal to perform propagation path correction for the PDCCH. Also, the CRS is used for the terminal to perform propagation path correction for the PDSCH. The CRS is also used by the terminal to calculate downlink channel state information.

  The CRS is transmitted for a plurality of terminals. The CRS is transmitted over the entire band in the downlink. Also, CRS is transmitted in all downlink subframes in a cell that supports PDSCH transmission.

  For example, for CRS transmission, one, two, or four antenna port configurations are supported. For example, the CRS is transmitted through one or more antenna ports of antenna ports 0 to 3. Hereinafter, the antenna port used for CRS transmission is also referred to as a third antenna port.

  Here, the terminal can assume that each of a plurality of antenna ports used for transmission of CRSs is quasi-correlated with respect to channel characteristics over a long period in a certain cell.

  As described above, the terminal can assume that the antenna port used for transmitting the same type of downlink reference signal is quasi-collocated. Here, the base station may set to the terminal whether or not the antenna port used for transmitting the same type of downlink reference signal is quasi-collocated.

  Here, in addition to the three types of downlink reference signals described above, the downlink reference signal includes an MBSFN reference signal (Multicast / Broadcast over Signal Frequency Reference signals) and a reference signal for demodulation related to EPDCCH. (Demodulation reference signals associated with EPDCCH) and positioning reference signals (Positioning reference signals) may be included. Hereinafter, the three types of downlink reference signals described above will be basically described.

  In FIG. 3, aggregation of a plurality of serving cells (also simply referred to as cells) may be supported in the downlink and uplink (carrier aggregation (CA) or cell aggregation (CA; Called Cell Aggregation). Here, in the carrier aggregation, one serving cell is defined as a primary cell (Pcell). In carrier aggregation, a serving cell other than the primary cell is defined as a secondary cell (Scell; Secondary Cell).

  Here, the serving cell may be defined as one serving cell including a primary cell for a terminal for which CA is not set. In addition, the serving cell may be defined as a set of (one or) a plurality of saving cells including a primary cell and a secondary cell for a terminal for which CA is set.

  Also, a carrier corresponding to a serving cell in the downlink is defined as a downlink component carrier (DLCC; Downlink Component Carrier). Also, a carrier corresponding to a primary cell in the downlink is defined as a downlink primary component carrier (DLPCC; Downlink Primary Component Carrier). A carrier corresponding to a secondary cell in the downlink is defined as a downlink secondary component carrier (DLSCC).

  In addition, a carrier corresponding to a serving cell in the uplink is defined as an uplink component carrier (ULCC). Further, a carrier corresponding to a primary cell in the uplink is defined as an uplink primary component carrier (ULPCC; Uplink Primary Component Carrier). Also, a carrier corresponding to a secondary cell in the uplink is defined as an uplink secondary component carrier (ULSCCC).

  For example, the primary cell is defined as a cell in which the terminal performs an initial connection establishment procedure. Also, the primary cell is defined as a cell from which the terminal starts a connection re-establishment procedure. A primary cell is defined as a cell indicated as a primary cell by a base station during a handover procedure.

  That is, the base station and the terminal can perform transmission / reception on a plurality of physical channels in a certain subframe. Here, each of the physical channels is mapped to any one serving cell. That is, a single physical channel is not mapped to multiple serving cells.

  FIG. 4 is a diagram illustrating an example of mapping between physical downlink channels and downlink reference signals. FIG. 4 shows two resource blocks (also referred to as resource block pairs) in one subframe. For example, one resource block is composed of 12 subcarriers in the frequency domain and 7 OFDM symbols in the time domain.

  Here, in one subframe, each of the 7 OFDM symbols in the time domain is also referred to as a slot. That is, one subframe is composed of a first slot and a second slot. Further, in one slot, a resource (minimum unit of time-frequency) defined by one OFDM symbol and one subcarrier is also called a resource element.

 That is, the physical downlink channel is mapped to a resource element (which may be a resource element of an OFDM symbol). Also, the downlink reference signal is mapped to the resource element.

  Here, in FIG. 4, Ri indicates a resource element (resource element used for CRS transmission) to which CRS in antenna port i is mapped (for example, i = 0, 1, 2, 3).

  Moreover, Di has shown the resource element (resource element used for transmission of PDSCH DM-RS) to which PDSCH DM-RS in PDSCH DM-RS group i is mapped (for example, i = 1, 2).

  Ci represents a resource element to which CSI-RS in CSI-RS group i is mapped (resource element used for transmission of CSI-RS) (for example, i = 1, 2, 3, 4). .

  Here, basically, the CRS is arranged in more resource elements in the time domain and the frequency domain than the PDSCH DM-RS and CSI-RS (density when arranged in the resource element). Is high).

  In addition, PDSCH DM-RSs are arranged in fewer resource elements in the time domain and the frequency domain than the CRS (the density when arranged in the resource elements is low).

  Here, CRS and CSI-RS are mapped over the entire downlink bandwidth. Also, a PDSCH DM-RS intended for a certain terminal is mapped only to the same downlink bandwidth as the PDSCH resource bandwidth scheduled for the terminal. That is, PDSCH DM-RS is mapped to a narrow bandwidth compared to CRS and CSI-RS.

  FIG. 5 is a diagram illustrating an example of physical downlink channel mapping. FIG. 5 shows a PDCCH resource region, an E-PDCCH resource region, and a PDSCH resource region. FIG. 5 also shows a common search space (CSS; Common Search Space) and user equipment specific search space (USS; UE-Specific Search Space, terminal-specific search space).

  As shown in FIG. 5, for example, the PDCCH may be time division multiplexed (TDM) with the PDSCH. Also, the E-PDCCH can be frequency division multiplexed (FDM) with the PDSCH. Hereinafter, E-PDCCH is included in PDCCH.

  Here, a plurality of formats (downlink control information format; DCI format) are defined for the downlink control information transmitted on the PDCCH.

  For example, a DCI format 1A used for scheduling one PDSCH (one PDSCH codeword, one downlink transport block transmission) in one cell is defined as a DCI format for the downlink. Hereinafter, the DCI format 1A is also referred to as a first DCI format.

  Also, as a DCI format for downlink, DCI format 2C used for scheduling of one PDSCH (up to two PDSCH codewords, transmission of up to two downlink transport blocks) in one cell is defined. The Hereinafter, the DCI format 2C is also referred to as a second DCI format or a third DCI format.

  That is, the DCI format 2C including the control information (hereinafter also referred to as first control information) shown in the description of FIG. 7 is described as the second DCI format. Also, the DCI format 2C that does not include information related to the control information (first control information) shown below is described as a third DCI format.

  Further, for example, a DCI format (hereinafter, also referred to as DCI format 2D) used for PDSCH scheduling in multi-cell communication may be defined as a DCI format for the downlink. Hereinafter, the DCI format 2D is also described as a second DCI format.

  Here, the third DCI format includes DCI format 1A, DCI format 1B, DCI format 1D, DCI format 2, DCI format 2A, DCI format 2B, DCI format 1A, DCI format 2C, and DCI format 2D. Different DCI formats may be included.

For example, in the DCI format for downlink, downlink control information such as information on PDSCH resource allocation, information on MCS (Modulation and Coding scheme), information on scrambling identity (also called scrambling link identifier, n _SCID ), etc. Is included. Here, the DCI format used for PDSCH scheduling is also described as downlink assignment.

  Here, the information on the scrambling identity may be used to indicate parameters used for generating a downlink reference signal (eg, PDSCH DM-RS) sequence. For example, information related to the scrambling identity is mapped to 3 information bits (fields).

  Here, for example, information (for example, the number of antenna ports and the number of layers) other than the information related to the scrambling identity may be instructed using the information bits of 3 bits. Further, these three information bits may be mapped to the control information (first control information) shown below.

  Further, for example, as a DCI format for uplink, scheduling of one physical uplink shared channel (PUSCH) in one cell (transmission of one PUSCH codeword, one uplink transport block) DCI format 0 used for the above is defined.

  Also, as a DCI format for uplink, DCI format 4 used for scheduling of one PUSCH (up to two PUSCH codewords, transmission of up to two uplink transport blocks) in one cell is defined. The

  Further, for example, as a DCI format for the uplink, a DCI format (hereinafter also referred to as DCI format 5) used for PUSCH scheduling in multi-cell communication may be defined.

  For example, the DCI format for uplink includes downlink control information such as information on PUSCH resource allocation and information on MCS (Modulation and Coding scheme). Hereinafter, the DCI format used for PUSCH scheduling is also referred to as an uplink grant.

  Here, the terminal monitors a set of PDCCH candidates (PDCCH candidates). Here, the PDCCH candidate indicates a candidate that may be mapped and transmitted by the base station. Moreover, a PDCCH candidate is comprised from one or several control channel element (CCE; Control Channel Element).

  In addition, the terminal monitors a set of E-PDCCH candidates (E-PDCCH candates). Here, the E-PDCCH candidate indicates a candidate that the E-PDCCH may be mapped and transmitted by the base station. Moreover, an E-PDCCH candidate is comprised from one or several E-control channel element (E-CCE; Enhanced Control Channel Element).

  Here, monitoring means that the terminal attempts to decode each PDCCH in the set of PDCCH candidates and / or E-PDCCH in the E-PDCCH candidates according to all the DCI formats to be monitored. means.

  A set of PDCCH candidates and a set of E-PDCCH candidates monitored by the terminal are also referred to as search spaces. That is, a search space is a set of resources that can be used by a base station for transmission of PDCCH or E-PDCCH.

  That is, CSS and / or USS are configured (defined and set) in the PDCCH resource region. In addition, CSS and / or USS is configured (defined and set) in the resource region of E-PDCCH.

  The base station transmits (arranges) the PDCCH in the CSS and / or USS of the PDCCH resource region. In addition, the terminal monitors the PDCCH in the CSS and / or USS of the PDCCH resource region, and detects the PDCCH addressed to itself.

  Further, the base station transmits (arranges) the E-PDCCH in the CSS and / or USS of the resource region of the E-PDCCH. In addition, the terminal monitors the E-PDCCH in the CSS and / or USS of the E-PDCCH resource region, and detects the E-PDCCH addressed to the terminal itself.

  Here, CSS is used for transmission of downlink control information to a plurality of terminals. That is, CSS is defined by resources common to a plurality of terminals. For example, the CSS is configured by CCEs having numbers defined in advance between the base station and the terminal (for example, CCEs having indexes from 0 to 15).

  Moreover, CSS may be used for transmission of downlink control information to a specific terminal. That is, the base station can transmit a DCI format intended for a plurality of terminals and / or a DCI format intended for a specific terminal in the CSS.

  The USS is used for transmission of downlink control information to a specific terminal. That is, USS is defined by resources dedicated to a certain terminal. That is, USS is defined independently for each terminal. For example, the USS includes a radio network temporary identifier (RNTI) assigned by a base station, a slot number in a radio frame, a number of CCEs determined based on an aggregation level, and the like. That is, the base station transmits a DCI format intended for a specific terminal in the USS.

  Here, for example, the DCI format 1A (first DCI format) is transmitted in CSS and / or USS. Further, the DCI format 2C / 2D (second DCI format) is transmitted only in the USS. Here, the DCI format 1 / 1B / 1D / 2 / 2A / 2B / 2C (third DCI format) may be transmitted only in the USS.

  That is, the first DCI format may be used for scheduling one PDSCH in one cell. Also, the first DCI format may be transmitted in CSS and / or USS for PDCCH and / or E-PDCCH. In addition, the first DCI format may not include the first control information.

  Further, the second DCI format may be used for scheduling one PDSCH in one cell. Also, the second DCI format may be transmitted only in the USS for PDCCH and / or E-PDCCH. The second DCI format may include first control information.

  Further, the third DCI format may be used for scheduling one PDSCH in one cell. Also, the third DCI format may be transmitted only in the USS for PDCCH and / or E-PDCCH. Further, the third DCI format may not include the first control information.

  Here, RNTI assigned to the terminal by the base station is used for transmission of downlink control information (transmission on PDCCH or E-PDCCH). Specifically, a CRC (Cyclic Redundancy Check parity bit (also simply referred to as CRC)) generated based on downlink control information (which may be a DCI format) is added to the downlink control information. , The CRC parity bit is scrambled with RNTI.

  That is, the terminal attempts to decode PDCCH / E-PDCCH (which may be downlink control information or DCI format) with CRC parity bits scrambled by RNTI, and the PDCCH for which the CRC is successful is changed to the PDCCH addressed to itself. / E-PDCCH (also called blind decoding).

  Here, RNTI includes C-RNTI (Cell RNTI). The RNTI includes RA-RNTI (Random Access RNTI). The RNTI includes P-RNTI (Paging RNTI). The RNTI includes SI-RNTI (System Information RNTI).

  Here, C-RNTI is a unique (unique) identifier used for RRC (Radio Resource Control) connection and scheduling identification. For example, C-RNTI is utilized for dynamically scheduled unicast transmissions.

  RA-RNTI is an identifier used when a random access response message is transmitted in a random access procedure. For example, when the terminal transmits a random access preamble, the terminal monitors the PDCCH with the CRC scrambled by the RA-RNTI.

  For example, the terminal performs a random access procedure in order to establish an initial connection establishment (initial connection establishment). The terminal also executes a random access procedure for handover. In addition, the terminal performs a random access procedure for connection re-establishment. In addition, the terminal executes a random access procedure to request UL-SCH resources.

  P-RNTI is an identifier used for notification of paging and system information. SI-RNTI is an identifier used for broadcasting system information.

  Here, PDCCH / E-PDCCH with CRC scrambled by C-RNTI may be transmitted in USS or CSS. Moreover, PDCCH / E-PDCCH with CRC scrambled by RA-RNTI may be transmitted only by CSS. Moreover, PDCCH / E-PDCCH with CRC scrambled by P-RNTI may be transmitted only by CSS. Moreover, PDCCH with CRC scrambled by SI-RNTI may be transmitted only by CSS.

  That is, the terminal changes the interpretation of the downlink control information based on which RNTI the CRC is scrambled with. Also, the terminal receives downlink data on the PDSCH scheduled using the downlink control information transmitted on the PDCCH. Hereinafter, transmission of downlink data on the PDSCH is also referred to as PDSCH transmission. Also, reception of downlink data on the PDSCH is also referred to as PDSCH reception.

  In addition, the base station and the terminal transmit and receive signals in an upper layer (Higher layer). For example, the base station and the terminal are also called radio resource control signals (RRC signaling; Radio Resource Control signaling, RRC message; Radio Resource Control message, RRC information; Radio Resource Control information) in the RRC layer (Layer 3). Send and receive.

  Here, in the RRC layer, a dedicated signal transmitted to a certain terminal by the base station is also referred to as a dedicated RRC signaling (dedicated signal, dedicated signaling). That is, a dedicated (unique) setting (information) for a certain terminal is transmitted by the base station using dedicated RRC signaling.

  Further, the base station and the terminal transmit and receive MAC control elements in a MAC (Media Access Control) layer (layer 2). Here, the RRC signaling and / or the MAC control element is also referred to as a higher layer signaling.

  FIG. 6 is a diagram for explaining the present embodiment. FIG. 6 shows a primary base station corresponding to the primary base station 301 in FIG. Also, two secondary base stations corresponding to the secondary base station 302 in FIG. 3 are shown. Further, a terminal corresponding to the terminal 303 in FIG. 3 is shown.

  As above-mentioned, in FIG. 6, the base station can set the parameter regarding CSI-RS to a terminal. For example, the base station can transmit a parameter related to a plurality of CSI-RSs (for example, CSI-RS resource # 1, CSI-RS resource # 2, CSI-RS resource # 3) in a dedicated RRC signaling. .

  Here, the base station sets a plurality of parameters related to CSI-RS (a set of parameters related to CSI-RS) using dedicated RRC signaling, and further sets one parameter from the plurality of parameters related to the set CSI-RS. The control information (may be the first control information) included in the DCI format (for example, downlink assignment) may be used for the instruction.

  Moreover, in FIG. 6, the base station can set the parameter regarding PDSCH DM-RS to a terminal. For example, the base station can transmit a parameter related to PDSCH DM-RS by including it in a dedicated RRC signaling.

  Here, the base station sets a plurality of parameters related to the PDSCH DM-RS (a set of parameters related to the PDSCH DM-RS) using the dedicated RRC signaling, and further sets 1 from the plurality of parameters related to the set PDSCH DM-RS. One parameter may be indicated using control information (may be the first control information) included in the DCI format (eg, downlink assignment).

  For example, the parameters related to the PDSCH DM-RS include information (for example, the value of the virtual cell identity) used to indicate a virtual cell identity (VCI) for the PDSCH DM-RS. Here, for example, the value of the virtual cell identity can be used to generate a PDSCH DM-RS sequence. Further, a physical layer cell identity may be used as a default value for each of the two virtual cell identity values.

  Hereinafter, the setting for PDSCH DM-RS is also referred to as PDSCH DM-RS configuration. That is, PDSCH DM-RS configuration is defined by a dedicated RRC signaling.

  In FIG. 6, the base station can set parameters related to CRS in the terminal. For example, the base station can transmit a parameter related to a plurality of CRSs (CRS (Cell ID # 1), CRS (Cell ID # 2), and CRS (Cell ID # 2)) in a dedicated RRC signaling. Here, for example, Cell ID # X (X = 1, 2, 3) indicates a physical layer cell identity. That is, for example, CRS (Cell ID # X) indicates CRS transmitted in a cell in which physical layer cell identity X is set.

  Here, the base station sets a plurality of parameters related to CRS (a set of parameters related to CRS) using dedicated RRC signaling, and further sets one parameter from the plurality of parameters related to the CRS to a DCI format (for example, The control information (which may be the first control information) included in the (downlink assignment) may be used for the instruction.

  For example, the CRS parameter includes information used to indicate the position of the CRS (hereinafter also referred to as CRS position). For example, the base station can set the position of a resource (which may be a resource element) to which each of a plurality of CRSs (for example, three CRSs) is mapped.

  For example, the information used to indicate the position of the CRS may include information for indicating the frequency shift (position in the frequency direction) of the CRS. Further, the information used to indicate the position of the CRS may include information indicating the number of antenna ports used for CRS transmission.

  For example, the parameters related to CRS may include information used to indicate physical layer cell identity X of CRS. Further, the CRS parameter may include information used to indicate the number of antenna ports used for CRS transmission. Here, the frequency shift of CRS (that is, the position of CRS) is determined (calculated) based on the physical layer cell identity.

  Here, the physical downlink channel is not mapped to the position of the resource element used for CRS. For example, when a PDSCH is mapped to a resource element, if a physical signal / physical channel other than the PDSCH (for example, CRS) is mapped to the resource element, the PDSCH is the physical signal / the physical channel. Is rate-matched to the resource element to which is mapped.

  Here, rate matching indicates, for example, processing for mapping PDSCH so as to avoid resource elements to which physical signals / physical channels other than PDSCH are mapped.

  That is, the PDSCH is mapped to resource elements excluding resource elements to which physical signals / physical channels other than PDSCH are mapped. That is, the PDSCH is mapped to resource elements that are not used for physical signals / physical channels other than the PDSCH.

  Here, if the terminal receives the PDSCH without assuming that the PDSCH has been rate-matched by the base station, the reception characteristics for the PDSCH deteriorate. Accordingly, it is preferable that the base station and the terminal transmit and receive the PDSCH based on resource elements to which physical signals / physical channels other than the PDSCH are mapped in order to avoid deterioration of reception characteristics for the PDSCH.

  That is, the terminal performs reception on the PDSCH based on the CRS position set by the base station. Here, as shown below, the terminal moves to the location of the CRS in the serving cell (at least the location of the CRS determined from the physical layer cell identity of the serving cell) in Behavior A (operation A) and Behavior B1 (operation B1). Based on this, reception on PDSCH is performed (hereinafter also referred to as reception of PDSCH based on PCI).

  In addition, when the terminal executes Behavior A (operation A) or Behavior B1 (operation B1), the base station sets the CRS position in the serving cell (at least the CRS position determined from the physical layer cell identity of the serving cell). Based on this, transmission on the PDSCH is performed (hereinafter also referred to as PDSCH transmission based on PCI).

  Also, as shown below, the terminal performs reception on PDSCH based on the CRS position set by the base station (the position of the CRS signaled to the terminal by the higher layer) in Behavior B2 (operation B2). (Hereinafter also referred to as PDSCH reception based on the first setting).

  Further, as shown below, the base station, when the terminal executes Behavior B2 (operation B2), based on the position of the CRS set in the terminal (the position of the CRS signaled to the terminal by the higher layer), PDSCH transmission is performed (hereinafter also referred to as PDSCH transmission based on the first setting).

  Here, the base station and the terminal receive the PDSCH based on the first setting, based on the CRS position set by the base station, in addition to the CRS position determined from the physical layer cell identity of the serving cell, You may perform transmission / reception by PDSCH.

  Hereinafter, the setting for CRS is also referred to as CRS configuration. That is, CRS configuration is defined by a dedicated RRC signaling.

  Further, in FIG. 6, the base station can set to the terminal whether or not the antenna port used for transmission of different types of downlink reference signals is quasi-collocated. That is, it can be assumed that the terminal is quasi-collocated with respect to the antenna port used for transmission of different types of downlink reference signals.

  For example, the base station is used to indicate whether the first antenna port and / or the second antenna port and / or the third antenna port is quasi-collocated. Information (hereinafter also referred to as a parameter relating to quasi-colocation) can be included in the dedicated RRC signaling and transmitted.

  Here, the parameter relating to the quasi-colocation may include the above-described parameter relating to the CRS. Moreover, the parameter regarding PDSCH DM-RS mentioned above may be contained in the parameter regarding quasi-colocation. Moreover, the parameter regarding CSI-RS may be included in the parameter regarding a quasi-colocation.

  Here, the base station may include a parameter relating to quasi-colocation in the terminal by including it in the CSI-RS configuration. In addition, the base station may include a parameter relating to quasi-colocation in PDSCH DM-RS configuration and set it in the terminal. In addition, the base station may include a parameter relating to the quatter location in the CRS configuration and set it in the terminal.

  For example, as illustrated in FIG. 6, the base station may set that CSI-RS resource # 1 is quasi-collocated with CRS (Cell ID # 1). Further, the base station may set that CSI-RS resource # 2 is CRS (Cell ID # 2) and quasi-collocated. Further, the base station may set that CSI-RS # resource 3 is CRS (Cell ID # 3) to be quasi-collocated.

  Further, the base station may set that PDSCH DM-RS is quasi-collocated with CRS (Cell ID # 2). Further, the base station may set that CSI-RS resource # 2 is quasi-collocated with PDSCH DM-RS.

  FIG. 7 is another diagram for explaining the present embodiment. As shown in FIG. 7, the base station configures a plurality of parameters relating to quasi-colocation (a set of parameters relating to quasi-colocation) using dedicated RRC signaling, and further, from the configured parameters relating to quasi-colocation. One parameter may be indicated using control information (first control information) included in a DCI format (for example, downlink assignment).

  For example, a 2-bit field (or 3-bit field) defined in the DCI format is mapped to the first control information. Here, as described above, a field mapped to information on the scrambling identity may be used as the first control information. For example, the first control information may be represented using a newly defined 2-bit field and a part or all of a 3-bit field mapped to information on the scrambling identity.

  Here, for example, the first control information may be included in a DCI format other than a predetermined DCI format. Here, the DCI format other than the predetermined DCI format indicates the DCI format 2D (second DCI format). The DCI format 2C may include first control information.

  Further, for example, the first control information may not be included in the predetermined DCI format. Here, the predetermined DCI format indicates the DCI format 1A (first DCI format). The predetermined DCI format may include a DCI format 1 / 1B / 1D / 2 / 2A / 2B / 2C (third DCI format).

  For example, the predetermined DCI format may be defined in advance according to specifications or the like. That is, the predetermined DCI format can be known information between the base station and the terminal.

  For example, the first control information may be included in the DCI format when the DCI format is transmitted on the PDCCH with the CRC scrambled with the C-RNTI. That is, the first control information may not be included in the DCI format when the DCI format is transmitted on the PDCCH with the CRC scrambled with the RA-RNTI. Further, the first control information may not be included in the DCI format when the DCI format is transmitted on the PDCCH accompanied by the CRC scrambled with the P-RNTI. In addition, the first control information may not be included in the DCI format when the DCI format is transmitted on the PDCCH accompanied by the CRC scrambled with the SI-RNTI.

  Further, for example, the first control information may be included in a part or all of the DCI formats only when set by the base station. For example, the base station may transmit information indicating whether or not the first control information is included in some or all of the DCI formats using the dedicated RRC signaling.

  Here, the base station can set the transmission mode for transmission on PDSCH (or reception on PDSCH) to the terminal. For example, the base station may transmit the information used for indicating the transmission mode by including it in the dedicated RRC signaling.

  Here, for example, the first control information may be included in a part or all of the DCI formats only when a predetermined transmission mode (for example, transmission mode 10) is set by the base station. . Hereinafter, the predetermined transmission mode (that is, transmission mode 10) is also referred to as a first transmission mode.

  That is, the first control information is included in the DCI format when a transmission mode other than the predetermined transmission mode (for example, any transmission mode from transmission mode 1 to transmission mode 9) is set by the base station. You don't have to. Hereinafter, a transmission mode other than the predetermined transmission mode (that is, any transmission mode from transmission mode 1 to transmission mode 9) is also referred to as a second transmission mode.

  For example, the base station may include the first control information in the DCI format 2C only when the transmission mode 10 is set. Further, the base station may include the first control information in the DCI format 2D only when the transmission mode 10 is set. Here, the base station may transmit the DCI format 2D only when the transmission mode 10 is set.

  Here, in the transmission mode 10, the terminal may monitor the DCI format 1A (first DCI format) and the DCI format 2D (second DCI format). Further, the terminal may monitor any one of the DCI format 1A (first DCI format) and the third DCI format in any transmission mode from transmission mode 1 to transmission mode 9.

  Here, the predetermined transmission mode may be defined in advance according to specifications or the like. That is, the predetermined transmission mode can be known information between the base station and the terminal. For example, the predetermined transmission mode may include a mode in which transmission on the PDSCH is performed in multicell communication.

  In FIG. 7, it is shown that the first set to the fourth set of parameters related to CSI-RS (four sets of parameters related to CSI-RS) are set. It is also shown that the first set to the fourth set of parameters related to CRS (four sets of parameters related to CRS) are set.

  Further, it is indicated that a parameter related to CSI-RS and a parameter related to CRS are indicated based on the first control information included in the DCI format. That is, based on the two information bits defined as the first control information (the states of “00”, “01”, “10”, “11” represented by the two information bits), the CSI− It is shown that parameters for RS and CRS are indicated.

  As illustrated in FIG. 7, the base station can indicate the CSI-RS resource using the first control information. Here, the base station indicates the CSI-RS resource using the first control information, and thereby the antenna port (the second port used for transmission of the CSI-RS mapped to the CSI-RS resource). It can be shown that (antenna port) is quasi-collocated with the antenna port (first antenna port) used for transmission of PDSCH DM-RS.

  That is, the base station transmits the second antenna only when the CSI-RS transmitted using the second antenna port is mapped to the CSI-RS resource indicated using the first control information. It can be shown that the port is quasi-collocated with the first antenna port.

  That is, the terminal uses the PDSCH DM-RS as an antenna port (second antenna port) used for transmission of CSI-RS mapped to the CSI-RS resource indicated using the first control information. It can be assumed that the antenna port (first antenna port) used for transmission is quasi-collocated.

  That is, the terminal transmits the second antenna port only when the CSI-RS transmitted using the second antenna port is mapped to the CSI-RS resource indicated using the first control information. Can be assumed to be quasi-collocated with the first antenna port.

  For example, the base station transmits the DCI format including the two information bits set to “00” (that is, the first control information), thereby setting the CSI-RS set using the first set. A resource (eg, CSI-RS resource # 2 as shown in FIG. 6) can be indicated. That is, only when the CSI-RS transmitted using the second antenna port is mapped to CSI-RS resource # 2, the second antenna port and the first antenna port are quasi-collocated. Can be shown.

  Further, the terminal receives the DCI format including the two information bits set to “00” (that is, the first control information), thereby transmitting the CSI transmitted using the second antenna port. It can be assumed that the second antenna port is quasi-collocated with the first antenna port only when the RS is mapped to CSI-RS resource # 2. Here, PDSCH (PDSCH resource) is scheduled using a DCI format including 2 bits of information bits (ie, first control information) set to “00”.

  Hereinafter, although the operation of the terminal will be basically described, it is a matter of course that the base station performs an operation corresponding to the operation of the terminal.

  Here, the terminal supports two operations. Hereinafter, operations supported by the terminal are also described as Behavior A and Behavior B. Further, Behavior B is defined as Behavior B1 and Behavior B2 based on conditions.

  Here, Behaviour A indicates that the terminal assumes that at least the first antenna port, the second antenna port, and the third antenna port are quasi-collocated.

  In addition, Behaviour A is configured so that each of the antenna ports used by the terminal to transmit all downlink signals (herein, the downlink signal may include a downlink reference signal) It may indicate that it is assumed to be a quasi-colated.

  Here, the terminal may receive PDSCH based on PCI in Behavior A. That is, the base station may transmit PDSCH based on PCI in Behavior A.

  In addition, the terminal may receive PDSCH DM-RS generated based on the physical layer cell identity in Behavior A. That is, the base station may generate a PDSCH DM-RS in Behavior A based on the physical layer cell identity.

  Further, Behaviour B1 indicates that the terminal assumes that at least the first antenna port and the second antenna port are not quasi-collocated (when quasi-colored. Indicates no assumptions).

  Here, Behaviour B1 may include that the terminal assumes that the first antenna port, the second antenna port, and the third antenna port are not quasi-collocated.

  In addition, the behavior B1 is configured such that the second antenna port is connected to the first antenna port only when the terminal transmits a CSI-RS in which a sequence is generated based on the PCI using the second antenna port. It may include assuming a quasi-colated.

  Also, Behaviour B1 may include assuming that the terminal is quasi-collocated on the first antenna port and the third antenna port.

  Here, the terminal may receive PDSCH based on PCI in Behavior B1. That is, the base station may transmit PDSCH based on PCI in Behavior B1.

  Further, the terminal may receive PDSCH DM-RS generated based on the physical layer cell identity in Behavior B1. That is, the base station may generate PDSCH DM-RS based on the physical layer cell identity in Behavior B1.

  In addition, the behavior B2 is an antenna in which the terminal uses at least an antenna port (second antenna port) used for transmission of CSI-RS mapped to CSI-RS resources for transmission of PDSCH DM-RS. Shows that the port is assumed to be quasi-colated. Here, the method of instructing the CSI-RS resource is as described above.

  That is, Behaviour B2 is configured such that the second antenna port is connected to the first antenna only when the CSI-RS transmitted by the terminal at least using the second antenna port is mapped to the CSI-RS resource. Shows that the port is assumed to be quasi-colated.

  Here, Behaviour B2 is an antenna port (first antenna port) used for transmitting CSI-RS mapped by the terminal to the CSI-RS resource, and an antenna port (first antenna port) used for transmitting CRS. Assuming that the antenna port) is quasi-colated.

  In addition, Behaviour B2 is configured such that the terminal has an antenna port (first antenna port) used for PDSCH DM-RS transmission and an antenna port (third antenna port) used for CRS transmission. It may include assuming it is cated.

  Here, the terminal may receive PDSCH based on the first setting in Behavior B2. That is, the base station may perform PDSCH transmission based on the first setting in Behavior B2.

  In addition, the terminal may receive PDSCH DM-RS generated based on the virtual cell identity in Behavior B2. That is, the base station may generate PDSCH DM-RS based on the virtual cell identity in Behavior B2.

  For example, Behavior B (Behaviour B1, Behavior B2) typically occurs when multi-cell communication (eg, DL CoMP; Downlink CoMP, ie, transmission mode 10) is configured in the downlink.

  Here, for example, in Behaviour A, the terminal uses a serving cell synchronization signal and CRS for time synchronization and / or frequency synchronization, and CSI-RS (for example, estimation of CSI) and PDSCH DM-RS (for example, The same synchronization may be applied to (PDSCH demodulation).

  Also, in Behavior A, the terminal uses CRS-based channel estimation parameters for channel estimation using CSI-RS (for example, CSI-RS estimation) and PDSCH DM-RS (for example, PDSCH demodulation). May be used. Here, for example, parameters for channel estimation based on CRS include delay spread (delay spread, ie, a filter in the frequency domain) and Doppler spread (doppler spread, ie, a filter in the time domain).

  In addition, in Behaviour B1, the terminal may not recognize any relevance regarding the antenna port. Here, Behaviour B1 may be defined as an operation in the case where the parameter regarding the quasi-colocation is not set by the base station (that is, when the effective value regarding the quasi-colocation is not set by the upper layer). .

  In this case, the UE may use a comprehensive channel estimation filter for channel estimation for PDSCH demodulation based on the PDSCH DM-RS, and may initialize the channel estimation filter. PDSCH DM-RS may be used, channel estimation filter based on CRS may be used, or channel estimation filter related to CSI-RS generated based on physical layer cell identity may be used. Also good.

  Also, for example, in Behavior B2, the terminal uses the serving cell CSI-RS for time synchronization and / or frequency synchronization, and applies the same synchronization to PDSCH DM-RS (eg, PDSCH demodulation). May be.

  Further, in Behavior B2, the terminal may use a channel estimation parameter based on CSI-RS for channel estimation using PDSCH DM-RS (for example, PDSCH demodulation). Here, for example, the parameters for channel estimation based on CSI-RS include delay spread (delay spread, ie, a filter in the frequency domain) and Doppler spread (doppler spread, ie, a filter in the time domain).

  Here, the terminal may switch the default operation based on the transmission mode set by the base station (for example, any transmission mode from transmission mode 1 to transmission mode 10).

  For example, when the transmission mode 10 (first transmission mode) is set by the base station, the terminal may execute Behavior B1 as a default operation.

  In addition, the terminal may execute Behavior A as a default operation when any one of the transmission modes 1 to 9 (second transmission mode) is set by the base station.

  FIG. 8 is a diagram illustrating an example of a flow according to the present embodiment. As illustrated in FIG. 8, the terminal switches between Behavior A (operation A), Behavior B1 (operation B1), and Behavior B2 (operation B2) based on the condition.

  That is, when the condition is A, the terminal executes Behavior A. Further, when the condition is B, the terminal executes Behavior B1. Further, when the condition is C, the terminal executes Behavior B2.

  Here, the condition may include at least a transmission mode. That is, the condition A may include that at least one of the transmission modes from the transmission mode 1 to the transmission mode 9 (second transmission mode) is set. The condition B may include at least that the transmission mode 10 (first transmission mode) is set. The condition C may include at least that the transmission mode 10 (first transmission mode) is set.

  The conditions may include at least the detected (decoded, received) DCI format (type of DCI format). That is, the condition A may include at least the detection of the DCI format 1A (first DCI format). The condition A may include at least the detection of the third DCI format.

  The condition B may include at least the detection of the DCI format 1A (first DCI format). Further, the condition B may include at least the detection of the third DCI format.

  The condition C may include at least the detection of the DCI format 2D (second DCI format). Here, the condition C may include detecting the DCI format 2C (second DCI format).

  For example, when any one of the transmission modes 1 to 9 (second transmission mode) is set and the terminal detects the DCI format 1A (first DCI format), the terminal selects Behavior A. Run. That is, when the terminal detects the first DCI format in the second transmission mode, at least the first antenna port, the second antenna port, and the third antenna port are quasi-collocated. Assuming that

  Further, when the transmission mode 10 (first transmission mode) is set and the terminal detects the DCI format 1A (first DCI format), the terminal executes Behavior B1. That is, when the terminal detects the first DCI format in the first transmission mode, it assumes that at least the second antenna port is not quasi-collocated with the first antenna port. .

  Further, when the transmission mode 10 (first transmission mode) is set and the terminal detects the DCI format 2D (second DCI format), the terminal executes Behavior B2. That is, when the terminal detects the second DCI format in the first transmission mode, at least the second antenna port used for transmission of the CSI-RS mapped to the CSI-RS resource is Assume that the first antenna port used for transmission of the PDSCH DM-RS is quasi-collocated. Here, the method of instructing the CSI-RS resource is as described above.

  That is, when the terminal detects the second DCI format in the first transmission mode, at least the CSI-RS transmitted using the second antenna port is mapped to the CSI-RS resource. Only when the second antenna port is quasi-collocated with the first antenna port.

  Here, when the transmission mode 10 (first transmission mode) is set and the terminal detects the DCI format 2C (second DCI format), the terminal may execute Behavior B2.

  Here, the condition A may include that the terminal detects (decodes and receives) the PDCCH in the CSS. For example, the condition A may include that the terminal detects the DCI format 1A in the CSS.

  In addition, the condition B may include that the terminal detects (decodes and receives) the PDCCH in the CSS. For example, the condition B may include that the terminal detects the DCI format 1A in the CSS.

  Condition C includes that the terminal detects (decodes and receives) the PDCCH in the USS. For example, the condition C may include that the terminal detects the DCI format 1A in the USS. In addition, the condition C may include that the terminal detects the DCI format 2D in the USS. In addition, the condition C may include that the terminal detects the DCI format 2C in the USS.

  In addition, the condition A may include that the terminal detects (decodes and receives) a PDCCH with a CRC scrambled by RA-RNTI. In addition, the condition A may include that the terminal detects a PDCCH with a CRC scrambled by the P-RNTI. In addition, the condition A may include that the terminal detects a PDCCH with a CRC scrambled by SI-RNTI.

  In addition, the condition B may include that the terminal detects (decodes and receives) a PDCCH with a CRC scrambled by the RA-RNTI. In addition, the condition B may include that the terminal detects a PDCCH with a CRC scrambled by the P-RNTI. In addition, the condition B may include that the terminal detects a PDCCH with a CRC scrambled by SI-RNTI.

  In addition, the condition C may include that the terminal detects (decodes and receives) a PDCCH with a CRC scrambled by the C-RNTI.

  Here, for example, when a predetermined transmission mode (transmission mode 10, first transmission mode) is set and the DCI format 1A is transmitted in USS, the first control information is included in the DCI format 1A. May be. That is, in this case, the DCI format 1A is regarded as the second DCI format.

  In addition, when a predetermined transmission mode (transmission mode 10, first transmission mode) is set and the DCI format 1A is transmitted by CSS, the first control information may not be included in the DCI format 1A. good. That is, in this case, the DCI format 1A is regarded as the first DCI format.

  In addition, when a transmission mode other than the predetermined transmission mode (a transmission mode from transmission mode 1 to transmission mode 9 or the second transmission mode) is set and DCI format 1A is transmitted in USS and / or CSS The first control information may not be included in the DCI format 1A. That is, in this case, the DCI format 1A is regarded as the first DCI format.

  By the above-described method, the base station and the terminal can efficiently communicate by transmitting and receiving a downlink reference signal based on the assumption regarding the quasi-colocation of the antenna port. For example, it is possible for base stations and terminals to dynamically switch assumptions regarding the antenna port's quasi-colocation and to transmit / receive downlink reference signals, thereby enabling efficient communication.

  In addition, in the period in which the base station and the terminal are configured in the upper layer (for example, the RRC layer) (for example, the period in which the configuration using the dedicated RRC signaling is performed), it is possible to use the condition A for the downlink. Reference signals can be transmitted and received. That is, in the period when the setting is ambiguous (unclear) that occurs when the setting is performed in the upper layer (the period in which the setting is inconsistent between the base station and the terminal), the downlink of the downlink using the condition A Reference signals can be transmitted and received.

  That is, communication can be continued even during a period in which the base station and the terminal are performing settings in the upper layer, and communication using radio resources can be performed efficiently.

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

  The program that operates in the primary base station, the secondary base station, and the terminal related to the present invention is a program (a program that causes a computer to function) that controls the CPU and the like so as to realize the functions of the above-described embodiments related to the present invention. Information handled by these devices is temporarily stored in the RAM at the time of processing, then stored in various ROMs and HDDs, read out by the CPU, and corrected and written as necessary. As a recording medium for storing the program, a semiconductor medium (for example, ROM, nonvolatile memory card, etc.), an optical recording medium (for example, DVD, MO, MD, CD, BD, etc.), a magnetic recording medium (for example, magnetic tape, Any of a flexible disk etc. may be sufficient. In addition, by executing the loaded program, not only the functions of the above-described embodiment are realized, but also based on the instructions of the program, the processing is performed in cooperation with the operating system or other application programs. The functions of the invention may be realized.

  In the case of distribution in the market, the program can be stored and distributed in a portable recording medium, or transferred to a server computer connected via a network such as the Internet. In this case, the storage device of the server computer is also included in the present invention. Moreover, you may implement | achieve part or all of the secondary base station in the embodiment as mentioned above, a secondary base station, and a terminal as LSI which is typically an integrated circuit. Here, each functional block of the secondary base station, the secondary base station, and the terminal 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's, and implementation using dedicated circuitry or general purpose processors is also possible. 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.

  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.

  The present invention is suitable for terminal apparatuses, base station apparatuses, communication methods, integrated circuits, and wireless communication systems.

100 base station 101 data control unit 102 transmission data modulation unit 103 radio unit 104 scheduling unit 105 channel estimation unit 106 reception data demodulation unit 107 data extraction unit 108 upper layer 109 antenna 200 terminal 201 data control unit 202 transmission data modulation unit 203 radio unit 204 Scheduling unit 205 Channel estimation unit 206 Received data demodulation unit 207 Data extraction unit 208 Upper layer 209 Antenna 301 Primary base station 302 Secondary base station 303 Terminals 304 and 305 Downlink

Claims (14)

A terminal device that communicates with a base station device,
When the first transmission mode is set and the first downlink control information format is detected, at least the first antenna used for transmitting the user equipment specific reference signal related to the physical downlink shared channel Assuming that the second antenna port used to transmit the port and channel state information reference signal is not quasi co-located,
When the first transmission mode is set and the second downlink control information format is detected, the channel state information reference signal transmitted using the second antenna port is Assume that the second antenna port is quasi-collocated with the first antenna port only when mapped to the indicated resource using control information included in the downlink control information format A terminal device characterized by that. When the first downlink control information format is detected in the second transmission mode, the third antenna port used for transmitting the first antenna port, the second antenna port, and the cell specific reference signal The terminal device according to claim 1, wherein the antenna port is assumed to be quasi-collocated. The terminal device according to claim 1 or 2, wherein when the first transmission mode is set, a plurality of resources for the channel state information reference signal are set. 4. The terminal device according to claim 2, wherein, when the second transmission mode is set, a single resource for the channel state information reference signal is set. 5. The first downlink control information format and the second downlink control information format are monitored when the first transmission mode is set. The terminal device in any one. The said 1st downlink control information format and the said 3rd downlink control information format are monitored when the said 2nd transmission mode is set. The Claims 2-5 characterized by the above-mentioned. The terminal device in any one. The said 1st downlink control information format is transmitted in the common search space with respect to a physical downlink control channel, and / or a user apparatus specific search space. The Claim 1 characterized by the above-mentioned. Terminal device. The terminal apparatus according to any one of claims 1 to 7, wherein the second downlink control information format is transmitted only in a user apparatus specific search space for the physical downlink control channel. The terminal apparatus according to any one of claims 1 to 8, wherein the control information is not included in the first downlink control information format and the third downlink control information format. The terminal apparatus according to any one of claims 1 to 9, wherein the control information is included in the second downlink control information format. A communication method of a terminal device that communicates with a base station device,
When the first transmission mode is set and the first downlink control information format is detected, at least the first antenna used for transmitting the user equipment specific reference signal related to the physical downlink shared channel Assuming that the second antenna port used to transmit the port and channel state information reference signal is not quasi co-located,
When the first transmission mode is set and the second downlink control information format is detected, the channel state information reference signal transmitted using the second antenna port is Assume that the second antenna port is quasi-collocated with the first antenna port only when mapped to the indicated resource using control information included in the downlink control information format A communication method characterized by the above. When the first downlink control information format is detected in the second transmission mode, the third antenna port used for transmitting the first antenna port, the second antenna port, and the cell specific reference signal The communication method according to claim 11, wherein the antenna port is assumed to be quasi-collocated. An integrated circuit mounted on a terminal device that communicates with a base station device,
When the first transmission mode is set and the first downlink control information format is detected, at least the first antenna used for transmitting the user equipment specific reference signal related to the physical downlink shared channel A function that assumes that the second antenna port used for transmission of the port and channel state information reference signal is not quasi co-located.
When the first transmission mode is set and the second downlink control information format is detected, the channel state information reference signal transmitted using the second antenna port is Assume that the second antenna port is quasi-collocated with the first antenna port only when mapped to the indicated resource using control information included in the downlink control information format An integrated circuit characterized by causing the terminal device to exhibit its function. When the first downlink control information format is detected in the second transmission mode, the third antenna port used for transmitting the first antenna port, the second antenna port, and the cell specific reference signal The integrated circuit according to claim 13, wherein the terminal device has a function that assumes that the antenna port is quasi-collocated.