Abstract: A base station which communicates with a user equipment (UE) is described. The RRC configuration information may indicate that a maximum number of codewords scheduled by DCI is two. The base station may comprise transmitting circuitry configured to, after a channel access procedure, transmit, to the UE, a PDSCH which contains only a first transport block. The base station may further comprise receiving circuitry configured to receive, from the UE, a HARQ-ACK feedback including at least a first HARQ-ACK information bit and a second HARQ-ACK information bit. The first HARQ-ACK information bit may correspond to the first transport block of the PDSCH. The second HARQ-ACK information bit may be set to NACK. A contention window for the channel access procedure may be adjusted using the HARQ-ACK feedback, wherein the second HARQ-ACK information bit may be ignored.

Abstract: A method for a base station which communicates with a user equipment (UE) in a bandwidth including a plurality of channel access sub-bands in a serving cell is described. The method may comprise sensing each of the plurality of the channel access sub-bands. The method may also comprise transmitting downlink signal after sensing. A counter and a contention window size may be managed per sub-band for channel access.

Abstract: A method for a base station which communicates with a user equipment (UE) is described. The method may comprise sending first radio resource control (RRC) configuration information. The first RRC configuration information may indicate code block group (CBG) transmission for a Physical Downlink Shared Channel (PDSCH). The method may also comprise sending second RRC configuration information. The second RRC configuration information may indicate Nmax which is a maximum CBGs per transport block. The method may further comprise, after a channel access procedure, transmitting, to the UE, a PDSCH containing a transport block with N CBG(s). N is an integer. The method may further comprise receiving, from the UE, a HARQ-ACK feedback including Nmax HARQ-ACK information bits for the transport block of the PDSCH. If N is smaller than Nmax, the HARQ-ACK information bit(s) for last Nmax-N CBG(s) may be set to NACK.

Abstract: In a radio system which allocates resources using as units resource blocks which are formed by frequency components and time components, control information for mobile station devices, and identification information which is used to identify a format for a control information transmission channel which transmits the control information is transmitted from the base station device to the mobile station devices by means of the control information transmission channel.

Abstract: A communication system includes a terminal apparatus and a base station apparatus. The terminal apparatus communicates with a base station apparatus by carrier aggregation using a plurality of serving cells, where each of the plurality of serving cells has a different frequency. In addition, the terminal apparatus removes a measurement identity relevant to a serving cell of the plurality of serving cells based on that the serving cell was removed.

Abstract: A first PDCCH and a second PDCCH are received in a first cell, the first PDCCH including resource allocation information for a PDSCH of the first cell, the second PDCCH including resource allocation information for a PDSCH of a second cell, and a receiver configured to monitor one or more first PDCCH candidates and one or more second PDCCH candidates in a control resource set and a decoding unit configured to decode a first PDCCH candidate of the one or more first PDCCH candidates and a second PDCCH candidate of the one or more second PDCCH candidates are included, wherein the second PDCCH candidate with a first aggregation level includes multiple CCEs that are shifted, based on a carrier indicator, relative to multiple CCEs constituting the first PDCCH candidate with the first aggregation level, and the second PDCCH candidate with a second aggregation level includes one or more CCEs among the multiple CCEs constituting the second PDCCH candidate with the first aggregation level.

Abstract: Multiple PDCCH candidate groups included in a search space of a second aggregation level are given based on at least one or more PDCCH candidates included in a search space of a first aggregation level. Each of the multiple PDCCH candidate groups corresponds to each of the at least one or more PDCCH candidates included in the search space of the first aggregation level.

Abstract: A user equipment (UE) receiving, from a base station (BS), a higher layer signal including first information used for configuring more than one sets of one or more downlink component carriers (DCCs). The UE receives, using a physical downlinkn k control channel (PDCCH) in a UE-specific search space in a first subframe, from the BS, downlink control information (DCI) including second information indicating a trigger for a transmission of channel state information (CSI), the transmission of the CSI being triggered for one set of the more than one sets of one or more DCCs, the DCI being used for scheduling of a physical uplink shared channel (PUSCH) in one uplink component carrier. The UE transmits, using the PUSCH in a second subframe, to the BS, the CSI for the one set of the more than one sets of one or more DCCs in a case that the DCI including the second information indicating the trigger for the transmission of the CSI is received in the user equipment search space.

Abstract: A mobile communication system and a communication method are provided in which, a base station apparatus can efficiently allocate, to a mobile station apparatus, an uplink resource for transmitting information indicating an ACK/NACK for downlink data. The mobile station apparatus that communicates with the base station apparatus, comprising: a scheduling unit configured to determine two physical uplink control channel resources for a transmission using a physical downlink shared channel in a case that a downlink transmission mode that supports the transmission of up to two downlink transport blocks using the physical downlink shared channel is configured for the secondary cell, and a physical downlink control channel that indicates the transmission using the physical downlink shared channel on the secondary cell is detected on the secondary cell.

Abstract: The present invention enables efficient transmission/reception of a signal including control information between a base station apparatus and a mobile station apparatus. To realize this, there are provided a receiver configured to receive an enhanced physical downlink control channel from the base station apparatus; a setting unit configured to be able to set, using at least a format of downlink control information included in the received enhanced physical downlink control channel, one of a plurality of possible sets of M, M being the number of first elements that constitute the enhanced physical downlink control channel; and a monitoring unit configured to monitor a search region in which the enhanced physical downlink control channel obtained on the basis of the set possible set of M is possibly mapped.

Abstract: A terminal apparatus monitors a set of first PDCCH candidates in one subframe in EUTRA and a set of second PDCCH candidates in one slot in NR, and transmits UE capability information. The UE capability information indicates at least a maximum number A of times of blind decoding in the set of the first PDCCH candidates and a maximum number B of times of blind decoding in the set of the second PDCCH candidates, the maximum numbers A and B being supported by the terminal apparatus.

Abstract: There are provided a base station, a terminal, and a communication system in a wireless communication system in which a base station and a terminal communicate with each other, in which the base station and the terminal can efficiently perform communication. The communication system includes a higher layer processing unit 605 configured to configure, at the base station, for each terminal, a first reference signal configuration for configuring a measurement target for channel state reporting, configured to configure, at the base station, for each terminal, a second reference signal configuration specifying a resource element to be excluded from the target of data demodulation in a case where the terminal demodulates data, and configured to configure, at the base station, for each terminal, a third reference signal configuration for configuring a measurement target for which a reference signal received power is to be measured by the terminal.

Abstract: A mobile station apparatus configures first and second timers related to first and second groups. A first group of cells uses a first uplink transmission timing, and a second group of secondary cells uses a second uplink transmission timing. When the first timer of the first group has expired: all transmission HARQ buffers in association with the cells of the first group are flushed, the second timer is considered as expired, and an uplink transmission on any cells except random access preamble transmission on the primary cell is stopped. In a case where the second timer of the second group has expired: all transmission HARQ buffers in association with the secondary cells of the second group are flushed, and an uplink transmission on any cells in the second group except random access preamble transmission on the any cells in the second group is stopped.

Abstract: There are provided a base station, a terminal, and a communication system in a wireless communication system in which a base station and a terminal communicate with each other, in which the base station and the terminal can efficiently perform communication. The communication system includes a higher layer processing unit 605 configured to configure, at the base station, for each terminal, a first reference signal configuration for configuring a measurement target for channel state reporting, configured to configure, at the base station, for each terminal, a second reference signal configuration specifying a resource element to be excluded from the target of data demodulation in a case where the terminal demodulates data, and configured to configure, at the base station, for each terminal, a third reference signal configuration for configuring a measurement target for which a reference signal received power is to be measured by the terminal.

Abstract: Selection of a suitable MCS improves throughput without increasing the number of pieces of control information. With RRC signaling, information on PDCCH and a CQI table that is referred to are associated with each other, and the CQI table that is referred to is determined based on information relating to the PDCCH. Thus, the CQI table that is referred to is selected at high speed. Furthermore, information relating to control information is control information that is included in the PDCCH or an ePDCCH. Furthermore, the information relating to the control information is a type of search space of the PDCCH or the ePDCCH.

Abstract: A mobile communication system and a communication method are provided in which, a base station apparatus can efficiently allocate, to a mobile station apparatus, an uplink resource for transmitting information indicating an ACK/NACK for downlink data. The mobile station apparatus that communicates with the base station apparatus, comprising: a scheduling unit configured to determine two physical uplink control channel resources for a transmission using a physical downlink shared channel in a case that a downlink transmission mode that supports the transmission of up to two downlink transport blocks using the physical downlink shared channel is configured for the secondary cell, and a physical downlink control channel that indicates the transmission using the physical downlink shared channel on the secondary cell is detected on the secondary cell.

Abstract: A communication system that includes at least a terminal apparatus and a base station apparatus. The terminal apparatus communicates with a base station apparatus by carrier aggregation using a plurality of serving cells, wherein each serving cell of the plurality of serving cells has a different frequency. The terminal apparatus receives (from the base station apparatus) a measurement configuration which includes a reporting configuration, a measurement object to indicate a measurement frequency and a measurement identity which links the measurement object to the reporting configuration. The terminal apparatus, in a case that an entry condition of the event corresponding with an event identity of the reporting configuration is fulfilled, transmits (to the base station apparatus) a measurement report which includes measurement results of all of the serving cells.

Abstract: A mobile station apparatus configures first and second timers related to first and second groups. A first group of cells uses a first uplink transmission timing, and a second group of secondary cells uses a second uplink transmission timing. When the first timer of the first group has expired: all transmission HARQ buffers in association with the cells of the first group are flushed, the second timer is considered as expired, and an uplink transmission on any cells except random access preamble transmission on the primary cell is stopped. In a case where the second timer of the second group has expired: all transmission HARQ buffers in association with the secondary cells of the second group are flushed, and an uplink transmission on any cells in the second group except random access preamble transmission on the any cells in the second group is stopped.

Abstract: A communication system includes a terminal apparatus and a base station apparatus. The terminal apparatus communicates with a base station apparatus by carrier aggregation using a plurality of serving cells, where each of the plurality of serving cells has a different frequency. In addition, the terminal apparatus removes a measurement identity relevant to a serving cell of the plurality of serving cells based on that the serving cell was removed.

Abstract: There is provided a terminal for performing OFDM (Orthogonal Frequency-Division Multiplexing) communication with a base station forming a cell. The terminal includes a control channel processing unit configured to monitor, in a sub-frame, a first control channel in a cell-specific search space that is a search space common within the cell, and a first control channel in a UE-specific search space that is a search space specific to the terminal. In a case where monitoring of a second control channel different from the first control channel that is in the cell-specific search space or the UE-specific search space is configured, the control channel processing unit monitors, in a sub-frame, at least both the first control channel in the cell-specific search space and the second control channel in the UE-specific search space.