Terminal device, base station device, communication method, and integrated circuit

1. A terminal device, comprising:

transmission circuitry configured and/or programmed to transmit a Rank Indicator (RI) for Physical Downlink Shared CHannel (PDSCH) transmission;

reception circuitry configured and/or programmed to

receive first information used for determining a first maximum number of layers being the first maximum number assumed for determining a bit width for the RI, and

receive a transport block on the PDSCH; and

decoding circuitry configured and/or programmed to decode a code block of the transport block;

wherein the transmission circuitry transmits capability information including second information and third information,

the second information indicates a second maximum number of the layers supported by the terminal device in a downlink, and a first UE category corresponding to first total number of soft channel bits capable of being utilized for Hybrid Automatic Repeat reQuest (HARQ) processing in the downlink,

the third information indicates a third maximum number of the layers supported by the terminal device in the downlink, and a second UE category corresponding to a second total number of soft channel bits capable of being utilized for Hybrid Automatic Repeat reQuest (HARQ) processing in the downlink,

in a case that a first transmission mode is configured, a rate matching for the code block is processed based on the first total number,

in a case that a second transmission mode different from the first transmission mode is configured and the first information is configured, a rate matching for the code block is processed based on the first total number, and

in a case that the second transmission mode is configured and the first information is not configured, a rate matching for the code block is processed based on the second total number.

2. The terminal device according to claim 1 , wherein the transmission circuitry transmits the RI on a Physical Uplink Shared CHannel (PUSCH).

3. A base station device, comprising:

reception circuitry configured and/or programmed to receive, from a terminal device, a Rank Indicator (RI) for Physical Downlink Shared CHannel (PDSCH) transmission;

transmission circuitry configured and/or programmed to

transmit, to the terminal device, first information used by the terminal device for determining a first maximum number of layers being the first maximum number assumed by the terminal device for determining a bit width for the RI, and

transmit, to the terminal device, a transport block on the PDSCH; and

coding circuitry configured and/or programmed to code a code block of the transport block,

wherein the reception circuitry receives capability information including second information and third information,

the second information indicates a second maximum number of the layers supported by the terminal device in a downlink, and a first UE category corresponding to a first total number of soft channel bits capable of being utilized for Hybrid Automatic Repeat reQuest (HARQ) processing in the downlink,

the third information indicates a third maximum number of the layers supported by the terminal device in the downlink, and a second UE category corresponding to a second total number of soft channel bits capable of being utilized for Hybrid Automatic Repeat reQuest (HARQ) processing in the downlink,

in a case that a first transmission mode is configured for the terminal device, a rate matching for the code block is processed based on the first total number,

in a case that a second transmission mode different from the first transmission mode is configured for the terminal device and the first information is configured, a rate matching for the code block is processed based on the first total number, and

in a case that the second transmission mode is configured for the terminal device and the first information is not configured, a rate matching for the code block is processed based on the second total number.

4. The base station device according to claim 3 , wherein the reception circuitry receives the RI on a Physical Uplink Shared CHannel (PUSCH).

5. A communication method used by a terminal device, the method comprising the steps of:

transmitting a Rank Indicator (RI) for Physical Downlink Shared CHannel (PDSCH) transmission;

receiving first information used for determining a first maximum number of layers being the first maximum number assumed for determining a bit width for the RI;

receiving a transport block on the PDSCH;

decoding a code block of the transport block; and

transmitting capability information including second information and third information,

wherein the second information indicates a second maximum number of the layers supported by the terminal device in a downlink, and a first UE category corresponding to a first total number of soft channel bits capable of being utilized for Hybrid Automatic Repeat reQuest (HARQ) processing in the downlink,

the third information indicates a third maximum number of the layers supported by the terminal device in the downlink, and a second UE category corresponding to a second total number of soft channel bits capable of being utilized for Hybrid Automatic Repeat reQuest (HARQ) processing in the downlink,

in a case that a first transmission mode is configured, a rate matching for the code block is processed based on the first total number,

in a case that a second transmission mode different from the first transmission mode is configured and the first information is configured, a rate matching for the code block is processed based on the first total number, and

in a case that the second transmission mode is configured and the first information is not configured, a rate matching for the code block is processed based on the second total number.

6. A communication method used by a base station device, the method comprising the steps of:

receiving, from a terminal device, a Rank Indicator (RI) for Physical Downlink Shared CHannel (PDSCH) transmission;

transmitting, to the terminal device, first information used by the terminal device for determining a first maximum number of layers being the first maximum number assumed by the terminal device for determining a bit width for the RI;

transmitting, to the terminal device, a transport block on the PDSCH;

coding a code block of the transport block; and

receiving capability information including second information and third information,

wherein the second information indicates a second maximum number of the layers supported by the terminal device in a downlink, and a first UE category corresponding to a first total number of soft channel bits capable of being utilized for Hybrid Automatic Repeat reQuest (HARQ) processing in the downlink,

the third information indicates a third maximum number of the layers supported by the terminal device in the downlink, and a second UE category corresponding to a second total number of soft channel bits capable of being utilized for Hybrid Automatic Repeat reQuest (HARQ) processing in the downlink,

in a case that a first transmission mode is configured for the terminal device, a rate matching for the code block is processed based on the first total number,

in a case that a second transmission mode different from the first transmission mode is configured for the terminal device and the first information is configured, a rate matching for the code block is processed based on the first total number, and

in a case that the second transmission mode is configured for the terminal device and the first information is not configured, a rate matching for the code block is processed based on the second total number.