User apparatus and transmission power control method

A base station comprising:

• a transmitter that transmits a plurality of parameters that become candidates of a parameter to be used;
• a receiver that receives an uplink (UL) signal transmitted from a terminal using a transmission power that is determined based on a pathloss estimation value, wherein a parameter to be used is selected from the plurality of parameters and the pathloss estimation value is determined using the selected parameter,
• wherein the parameter to be used from the plurality of parameters is determined based on a Medium Access Control (MAC) signaling, and
• wherein the UL signal, subject to the transmission power determination, is a Sounding Reference Signal (SRS) that is used for crosslink interference measurement.

A radio communication system comprising:

• a terminal that comprises:
• a first receiver that receives a plurality of parameters that become candidates of a parameter to be used;
• a processor that selects a parameter to be used, from the plurality of parameters, determines a pathloss estimation value using the selected parameter, and determines a transmission power of an uplink (UL) signal based on the pathloss estimation value;
• and
• a first transmitter that transmits the UL signal using the transmission power determined by the processor,
• wherein the processor determines the parameter to be used from the plurality of parameters based on a Medium Access Control (MAC) signaling, and
• wherein the UL signal, subject to the transmission power determination, is a Sounding Reference Signal (SRS) that is used for crosslink interference measurement, and
• a base station that comprises:
• a second transmitter that transmits the plurality of parameters;
• and
• a second receiver that receives the UL signal.

An uplink (UL) signal transmission method executed by a terminal, comprising:

• receiving a plurality of parameters that become candidates of a parameter to be used;
• selecting a parameter to be used, from the plurality of parameters, determining a pathloss estimation value using the selected parameter, and determining a transmission power of an UL signal based on the pathloss estimation value;
• transmitting the UL signal using the determined transmission power;
• and
• determining the parameter to be used from the plurality of parameters based on a Medium Access Control (MAC) signaling,
• wherein the UL signal, subject to the transmission power determination, is a Sounding Reference Signal (SRS) that is used for crosslink interference measurement.