Terminal device, base station device, communication system, and communication method

A terminal device, capable of reporting information about reception quality to a base station device based on a first feedback mode in which said terminal device periodically reports said information and a second feedback mode in which said terminal device aperiodically reports said information, comprising:

• a generation unit for generating a rank indicator specifying a preferred rank, first partial precoder information and second partial precoder information specifying a preferred precoder, and a reception quality indicator specifying a preferred transmission rate, as said information about the reception quality, in each of said first feedback mode and said second feedback mode;
• and
• a communication unit for carrying out communication with said base station device,
• wherein said preferred precoder is specified by a combination of said first partial precoder information and said second partial precoder information,
• in said first feedback mode, said communication unit is adapted to report said second partial precoder information and said reception quality indicator in a first subframe, and report said rank indicator and said first partial precoder information in a second subframe different from said first subframe, and
• in said second feedback mode, said communication unit is adapted to report said rank indicator, said first partial precoder information, said second partial precoder information, and said reception quality indicator in the same subframe.

A base station device, capable of configuring, for a terminal device, a first feedback mode in which said terminal device periodically reports information about reception quality in said terminal device, and a second feedback mode in which said terminal device aperiodically reports said information,

• wherein, in receiving a rank indicator specifying a preferred rank, first partial precoder information and second partial precoder information specifying a preferred precoder, and a reception quality indicator specifying a preferred transmission rate, as said information about the reception quality, from said terminal device in each of said first feedback mode and said second feedback mode,
• in a case that said base station device configures said first feedback mode, said base station device allocates, to said terminal device, a resource for reporting said second partial precoder information and said reception quality indicator in a first subframe, and a resource for reporting said rank indicator and said first partial precoder information in a second subframe different from said first subframe, and
• in a case that said base station device configures said second feedback mode, said base station device allocates, to said terminal device, a resource for simultaneously reporting said rank indicator, said first partial precoder information, said second partial precoder information, and said reception quality indicator.

A communication system, comprising:

• a base station device;
• and
• a terminal device for carrying out communication with said base station device,
• wherein said base station device is capable of configuring, for said terminal device, a first feedback mode in which said terminal device periodically reports information about reception quality in said terminal device, and a second feedback mode in which said terminal device aperiodically reports said information, and
• in receiving a rank indicator specifying a preferred rank, first partial precoder information and second partial precoder information specifying a preferred precoder, and a reception quality indicator specifying a preferred transmission rate, as said information about the reception quality, from said terminal device in each of said first feedback mode and said second feedback mode,
• in a case that said base station device configures said first feedback mode, said base station device is adapted to allocate, to said terminal device, a resource for reporting said second partial precoder information and said reception quality indicator in a first subframe, and a resource for reporting said rank indicator and said first partial precoder information in a second subframe different from said first subframe, and
• in said first feedback mode, said terminal device is adapted to report said second partial precoder information and said reception quality indicator in said first subframe, and report said rank indicator and said first partial precoder information in said second subframe different from said first subframe, and
• in said second feedback mode, said terminal device is adapted to report said rank indicator, said first partial precoder information, said second partial precoder information, and said reception quality indicator in the same subframe.

A processing method in a terminal device, comprising:

• generating, in a case that said terminal device reports information about reception quality to a base station device based on a first feedback mode in which said terminal device periodically reports said information and a second feedback mode in which said terminal device aperiodically reports said information, a rank indicator specifying a preferred rank, first partial precoder information and second partial precoder information specifying a preferred precoder, and a reception quality indicator specifying a preferred transmission rate, as said information about the reception quality, in each of said first feedback mode and said second feedback mode, said preferred precoder being specified by a combination of said first partial precoder information and said second partial precoder information;
• in said first feedback mode, reporting said second partial precoder information and said reception quality indicator in a first subframe, and reporting said rank indicator and said first partial precoder information in a second subframe different from said first subframe;
• and
• in said second feedback mode, reporting said rank indicator, said first partial precoder information, said second partial precoder information, and said reception quality indicator in the same subframe.

A processing method in a base station device,

• said base station device being capable of configuring, for a terminal device, a first feedback mode in which said terminal device periodically reports information about reception quality in said terminal device, and a second feedback mode in which said terminal device aperiodically reports said information,
• in receiving a rank indicator specifying a preferred rank, first partial precoder information and second partial precoder information specifying a preferred precoder, and a reception quality indicator specifying a preferred transmission rate, as said information about the reception quality, from said terminal device in each of said first feedback mode and said second feedback mode, the processing method comprising:
• in a case that said base station device configures said first feedback mode, allocating, to said terminal device, a resource for reporting said second partial precoder information and said reception quality indicator in a first subframe, and a resource for reporting said rank indicator and said first partial precoder information in a second subframe different from said first subframe;
• and
• in a case that said base station device configures said second feedback mode, allocating, to said terminal device, a resource for simultaneously reporting said rank indicator, said first partial precoder information, said second partial precoder information, and said reception quality indicator.

A terminal device, capable of reporting information about reception quality based on a first feedback mode in which said terminal device periodically reports said information and a second feedback mode in which said terminal device aperiodically reports said information and has a larger transmission capacity of information than that of said first feedback mode, comprising:

• a generation unit for generating a rank indicator specifying a preferred rank, first partial precoder information and second partial precoder information specifying a preferred precoder, and a reception quality indicator specifying a preferred transmission rate, as said information about the reception quality, in each of said first feedback mode and said second feedback mode;
• and
• a communication unit for carrying out communication with a base station device,
• wherein said preferred precoder is specified by a combination of said first partial precoder information and said second partial precoder information,
• in said first feedback mode, said communication unit is adapted to code said first partial precoder information together with said rank indicator and transmit them, and
• in said second feedback mode, said communication unit is adapted to code said first partial precoder information together with said second partial precoder information and said reception quality indicator and transmit them.

A processing method in a terminal device,

• said terminal device being capable of reporting information about reception quality to a base station device based on a first feedback mode in which said terminal device periodically reports said information and a second feedback mode in which said terminal device aperiodically reports said information and has a larger transmission capacity of information than that of said first feedback mode,
• the processing method comprising:
• generating a rank indicator specifying a preferred rank, first partial precoder information and second partial precoder information specifying a preferred precoder, and a reception quality indicator specifying a preferred transmission rate, as said information about the reception quality, in each of said first feedback mode and said second feedback mode, said preferred precoder being specified by a combination of said first partial precoder information and said second partial precoder information;
• in said first feedback mode, coding said first partial precoder information together with said rank indicator and transmitting them;
• and
• in said second feedback mode, coding said first partial precoder information together with said second partial precoder information and said reception quality indicator and transmitting them.

A processing method in a base station device,

• said base station device being capable of configuring, for a terminal device, a first feedback mode in which said terminal device periodically reports information about reception quality in said terminal device, and a second feedback mode in which said terminal device aperiodically reports said information,
• in a case that said base station device receives a rank indicator specifying a preferred rank, first partial precoder information and second partial precoder information specifying a preferred precoder, and a reception quality indicator specifying a preferred transmission rate, as said information about the reception quality, from said terminal device in each of said first feedback mode and said second feedback mode, the processing method comprising:
• in said first feedback mode, allocating a resource for transmitting said first partial precoder information jointly coded with said rank indicator;
• and
• in said second feedback mode, allocating a resource for transmitting said first partial precoder information jointly coded with said second partial precoder information and said reception quality indicator.