Abstract: Communication opportunities of existing terminal devices are ensured, in a communication system in which terminal devices capable of using a new CCA level and the existing terminal devices using an existing CCA level coexist, on the premise of CSMA/CA. A communication method of a radio transmission device of the present invention includes a step of signaling information indicating a first CCA section and a second CCA section to the radio reception device. A communication method of a radio reception device of the present invention includes a step of performing the carrier sense based on a first CCA level and a second CCA level, and a step of performing the carrier sense based on the first CCA level, in the first CCA section, based on information indicating the first CCA section.

Abstract: A CCA level is made to be variable efficiently while maintaining the fairness relating to acquisition of a transmission opportunity by wireless terminal apparatuses, and thus efficiency of a radio resource is improved. Provided is a terminal apparatus that, performs wireless communication with a base station apparatus, and includes; a MAC frame categorization unit categorizing MAC frames, in each of which media access control header is attached to transmission data, based on a type of MAC frame; and a QoS control unit performing a carrier sense using a first CCA level, in a case where the MAC frame is included in a first category that results from the categorization by the MAC frame categorization unit, and performing the carrier sense using a second CCA level different from the first CCA level, in a case where the MAC frame is included in a second category different from the first category.

Abstract: A terminal apparatus receives a PDCCH including a DCI format, and performs PUSCH transmission based on detection of the PDCCH. In an HARQ process corresponding to the PUSCH transmission, a value of an UL HARQ Round Trip Timer (RTT) timer for the HARQ process is provided based at least on a first condition and/or a second condition. The first condition is that a search space for the PDCCH detected is either a common search space or a UE-specific search space. The second condition is that a type of the HARQ process is either a synchronous HARQ or an asynchronous HARQ.

Abstract: A terminal apparatus increments a transmit counter based on a failure of random access response reception or contention resolution, and receives information for indicating a higher layer parameter powerRampingStep(1) and information for indicating a higher layer parameter powerRampingStep(2). A transmit power for PRACH transmission in a first step of a 2 step contention based random access procedure is given based at least on the transmission counter and the higher layer parameter powerRampingStep(1), and a transmit power for PUSCH transmission in the first step of the 2 step contention based random access procedure is given based at least on the transmission counter and the higher layer parameter powerRampingStep(2).

Abstract: A terminal apparatus includes: a higher layer processing unit configured to control a step-random access procedure; and a transmitter configured to transmit, as a first step of the 2 step-random access procedure, a random access preamble and data, in which the data include information relating to the random access preamble, and the information relating to the random access preamble includes some or all of following information A to information C: Information A for indicating an index of the random access preamble, Information B for indicating a resource for transmission of the random access preamble, and Information C relating to a sequence of the random access preamble.

Abstract: A terminal apparatus includes a receiver configured to receive a transport block, and a decoding unit configured to decode the plurality of first code blocks, in which each of the plurality of first code blocks is coded based on a soft buffer size, the soft buffer size is given based on at least a first value, the first value is the number of the plurality of first code blocks in an initial transmission of the transport block, the number of the plurality of first code blocks is given based on a size of the transport block, the size of the transport block is given based on at least an MCS field included in the downlink control information, in a case that at least one second code block is retransmitted, the first value is the number of the at least one second code block, and the at least one second code block includes some code blocks of the plurality of first code blocks resulting from the segmentation.

Abstract: A terminal apparatus includes a reception unit configured to receive a common channel, a decoding unit configured to generate an acknowledgement response based on whether a transport block in the common channel has been successfully decoded, and a transmission unit configured to transmit uplink control information including the acknowledgement response. Whether the uplink control information includes reception quality information is given at least based on the acknowledgement response, and the reception quality information is given based on a signal received by the reception unit.

Abstract: A signal that is transmitted to a terminal apparatus itself is demodulated with high precision, and throughput is improved. A terminal apparatus that communicates with a base station apparatus includes: a reception unit that receives downlink control information from the base station apparatus; and a signal detection unit that demodulates a signal that is transmitted to the terminal apparatus itself, based on first modulation mapping, and demodulates an interference signal based on second modulation mapping, in a case where information relating to a transmit power of the interference signal is included in the downlink control information.

Abstract: An object of the present invention is to protect the communication of a legacy terminal while achieving favorable communication by rendering the CCA level of a CCA-variable terminal apparatus variable in an environment, premised on CSMA/CA, where the CCA-variable terminal apparatus and a legacy terminal apparatus coexist. A terminal apparatus for performing wireless communication with a base station apparatus includes: a receiving unit that receives a radio signal transmitted from the base station apparatus; a CCA-variable channel information processing unit that acquires first CCA-variable channel instruction information contained in the radio signal and containing information regarding a range of a CCA level that is available on a certain channel and that is used for clear channel assessment; and a higher layer unit that selects, according to the first CCA-variable channel instruction information, a channel to be used.

Abstract: A method that carries out uplink multiple access while reducing complexity in processing accompanying exchange of control information. A terminal device that performs uplink multiple access communication includes a reception unit that receives a frame including first uplink multiple access information, and a transmission unit that transmits a frame including second uplink multiple access information based on the frame including the first uplink multiple access information, and further, after standby of a predetermined period, initiates the uplink multiple access communication.

Abstract: A terminal apparatus performs a random access procedure; and receives a physical channel, in which the random access procedure includes a 2 step contention based random access procedure, a 4 step contention based random access procedure, and a non-contention based random access procedure, and the physical channel indicates an initiation of any of the 4 step contention based random access procedure and the non-contention based random access procedure.

Abstract: This terminal apparatus is provided with: a receiver configured to receive at least a first physical signal and/or a second physical signal, wherein the first physical signal is generated during a first period, the first physical signal corresponds to a first beam during the first period, the second physical signal corresponds to the first beam in a case that the second physical signal is generated during the first period, and the second physical signal corresponds to a second beam in a case that the second physical signal is generated during a second period.

Abstract: A terminal apparatus receives a PDCCH including downlink control information; transmits a PUSCH including a transport block, based on detection of the PDCCH; and triggers non-adaptive retransmission without waiting for a feedback for preceding transmission in a bundle, when a parameter of an RRC layer is configured to be TRUE. A size of the transport block is given at least based on whether the parameter of the RRC layer is configured to be TRUE.

Abstract: Included is an uplink power control unit configured not to apply a first correction value obtained from a TPC command included in a first DCI format to transmit power for a PUSCH and applies a second correction value obtained from a TPC command included in a second DCI format to transmit power for an sPUSCH, in a case that a subframe m is later than a subframe n, that a subframe m+B for transmitting the sPUSCH is earlier than a subframe n+A for transmitting the PUSCH, and that a transmission subframe for the PUSCH and a transmission subframe for the sPUSCH belong to an identical uplink power control subframe set in a first serving cell.

Abstract: A terminal apparatus controls a 2 step-random access procedure; and transmits, as a first step of the 2 step-random access procedure, a random access preamble and data, in which one or both of (1) a scrambling sequence used for scrambling of a physical channel including the data and (2) a parameter used for generation of a demodulation reference signal associated with the physical channel including the data are determined based on one or both of (3) an index of the random access preamble and (4) a resource for transmission of the random access preamble.

Abstract: A method that carries out uplink multiple access while reducing complexity in processing accompanying exchange of control information. A terminal device that performs uplink multiple access communication includes a reception unit that receives a frame including uplink multiple access connection information, a first autonomous decentralized control unit that instructs securing time of a wireless resource, and a second autonomous decentralized control unit that instructs securing time of a wireless resource after reception of a frame including the uplink multiple access connection information. The terminal device is instructed securing time of the wireless resource by the first autonomous decentralized control unit in a case that a frame including the uplink multiple access connection information is not received. Securing time of the wireless resource is instructed by the second autonomous decentralized control unit in a case that a frame including the uplink multiple access connection information is received.

Abstract: A terminal apparatus includes: a receiver configured to receive higher layer signaling; and a decoding unit configured to attempt to decode a PDCCH in a control resource set, in which in a time domain, granularity of a physical characteristic of the PDCCH is considered to be X symbols, a value of the X is given by the higher layer signaling, and the higher layer signaling includes information for indicating the number of OFDM symbols of the control resource set.

Abstract: The terminal apparatus derives CSI, transmits the CSI, and determines content of the CSI based on a type of a downlink physical channel that is allocated to a CSI reference resource or allocated before and closest to the CSI reference resource.

Abstract: A bi-directional communication method needs to be switched on the basis of cost of bi-directional communication. Provided is a communication system including a first terminal apparatus and a second terminal apparatus, in which the first terminal apparatus includes a radio unit that transmits a first signal by using a first communication path that is a direct communication path to the second terminal apparatus, the second terminal apparatus includes a radio unit that transmits a second signal by using a second communication path that is a communication path different from the first communication path, and the first terminal apparatus transmits the first signal on the basis of a feature amount of the second signal transmitted by the second terminal apparatus.

Abstract: An object of the present invention is to protect the communication of a legacy terminal while achieving favorable communication rendering the CCA level of a CCA-variable terminal apparatus variable in an environment, premised on CSMA/CA, where the CCA-variable terminal apparatus and a legacy terminal apparatus coexist. A terminal apparatus for performing wireless communication with a base station apparatus includes: a receiving unit that receives a radio signal transmitted from the base station apparatus; a CCA-variable channel information processing unit that acquires first CCA-variable channel instruction information contained in the radio signal and containing information regarding a range of a CCA level that is available on a certain channel and that is used for clear channel assessment; and a higher layer unit that selects, according to the first CCA-variable channel instruction information, a channel to be used.