Base station device, terminal device, wireless communication system, and communication method

1. A base station device that communicates with a first terminal device that transmits first data, the base station device comprising:

a controller configured to determine whether a calculation method for a single term among a plurality of terms included in an equation for determining a transmission power of the first terminal device is either a first method or a second method, the first method using a relative value based on a previous value of the single term, the second method using an absolute value that is irrelevant to the previous value of the single term; and

a transmitter configured to transmit, to the first terminal device, notification information for notifying the calculation method determined by the controller, wherein

the controller selects the first method or the second method as the calculation method to determine the transmission power of the first terminal device in accordance with a type of data transmitted by the first terminal device, and wherein

the controller is further configured to select, based on the type of data transmitted by the first terminal device being a first type, the first method as the calculation method to determine the transmission power of the first terminal device, and

the controller is further configured to select, based on the type of data transmitted by the first terminal device being a second type, the second method as the calculation method to determine the transmission power of the first terminal device.

2. The base station device according to claim 1 , wherein the transmitter transmits a transmission power control command designating a value corresponding to the relative value or the absolute value.

3. The base station device according to claim 1 , wherein the controller

determines whether a communication environment between the base station device and a terminal device has changed, and

selects the second method when it is determined that the communication environment has changed.

4. The base station device according to claim 1 , wherein

the controller selects the second method as a method for calculating a transmission power for a resource used by a first terminal device to transmit second data, and

the transmitter transmits the notification information indicating that the second method is selected to a second terminal device.

5. The base station device according to claim 1 , wherein

the controller

identifies a resource used by a first terminal device to transmit data, the first terminal device communicating with another base station device different from the base station device, and

selects the second method as a method for calculating a transmission power for the resource identified, and

the transmitter transmits the notification information indicating that the second method is selected to a second terminal device communicating with the base station device.

6. The base station device according to claim 5 , wherein

the controller determines a position of the second terminal device, and

the transmitter transmits the notification information indicating that the second method is selected to the second terminal device in a case where it is determined that a distance from the base station device to the second terminal device is more than a predetermined distance.

7. A terminal device comprising:

a receiver configured to receive notification information indicating whether a method for calculating a single term among a plurality of terms included in an equation for determining a transmission power is either a first method or a second method, the first method using a relative value based on a previous value of the single term, the second method using an absolute value that is irrelevant to the previous value of the single term;

a controller configured to calculate a transmission power by using the first method or the second method in accordance with the notification information received by the receiver; and

a transmitter configured to transmit a signal with the transmission power calculated by the controller, wherein the notification information includes information indicating selection of the first method or the second method as the calculation method to determine the transmission power of an own terminal device in accordance with a type of data transmitted by the terminal device, wherein

the first method is selected as the calculation method to determine the transmission power of the terminal device based on the type of data transmitted by the terminal device being a first type, and

the second method is selected as the calculation method to determine the transmission power of the terminal device based on the type of data transmitted by the terminal device being a second type.

8. A wireless communication system comprising:

a base station device; and

a first terminal device,

the base station device including:

a first controller configured to determine whether a calculation method for a single term among a plurality of terms included in an equation for determining a transmission power of the first terminal device is either a first method or a second method, the first method using a relative value based on a previous value of the single term, the second method using an absolute value that is irrelevant to the previous value of the single term; and

a transmitter configured to transmit notification information for notifying the calculation method determined by the first controller, wherein the first controller selects the first method or the second method as the calculation method to determine the transmission power of the first terminal device in accordance with a type of data transmitted by the first terminal device, and

the transmitter transmits the notification information to the first terminal device, wherein the first controller is further configured to select, based on the type of data transmitted by the first terminal device being a first type, the first method as the calculation method to determine the transmission power of the first terminal device, and

the first controller is further configured to select, based on the type of data transmitted by the first terminal device being a second type, the second method as the calculation method to determine the transmission power of the first terminal device, and

the first terminal device including:

a receiver configured to receive the notification information transmitted from the base station device;

a second controller configured to calculate a transmission power by using the first method or the second method in accordance with the notification information received by the receiver; and

a transmitter configured to transmit a signal with the transmission power calculated by the second controller.