Mobile communication system, mobile terminal, transmit power control method in a mobile terminal, and program

A mobile terminal comprising:

• a transmission/reception unit for transmitting and receiving radio signal to/from a radio base station;
• a transmission/reception control unit for performing control relating to transmitting and receiving in the transmission/reception unit;
• a measurement unit for measuring an interference signal code power (ISCP) and a dedicated physical channel (DPCH) power, which are communication quality values in a present communication environment;
• a quality characteristic value conversion unit for drawing a relationship between an ISCP and a DPCH power;
• and
• a control unit for determining a target DPCH power corresponding to the measured ISCP by referring to the quality characteristic value conversion unit, comparing the measured DPCH power and the target DPCH power, generating a transmit power control (TPC) signal based on a comparison result, and outputting the TPC signal to the transmission/reception control unit.

A transmit-power control method in a mobile terminal which transmits a transmit power control (TPC) signal to a transmitting end based on communication quality values, the transmit power control method comprising:

• measuring an interference signal code power (ISCP) and a dedicated physical channel (DPCH) power, which are communication quality values in a present, communication environment;
• determining a target DPCH power corresponding to the measured ISCP by referring to a quality characteristic value conversion tool previously prepared;
• comparing the measured DPCH power and the target DPCH power;
• and
• transmitting a TPC signal to the transmitting end based on a comparison result.

A computer program recorded on a computer readable medium for executing transmit power control method which a receiving end performs based on measured communication quality for controlling transmit power of a transmitting end, the program comprising:

• measuring an interference signal code power (ISCP) and a dedicated physical channel (DPCH) power, which are communication quality values in a present communication environment;
• determining a target DPCH power corresponding to the measured, ISCP by referring to a quality characteristic value conversion tool previously prepared;
• comparing the measured DPCH power and the target DPCH power;
• and
• transmitting a TPC signal to the transmitting end based on a comparison result.