Transmission power control apparatus and transmission power control method

A mobile station apparatus equipped with a transmission power control apparatus, said transmission power control apparatus comprising:

• measuring means for measuring a received SIR value which is a reception desired signal to interference ratio;
• setting means for setting a target SIR value decreased by a predetermined first value when received signal quality is better than a desired quality, or setting said target SIR value increased by a second value that is greater than said first value if received signal quality is poorer than said desired quality;
• and
• generating means for generating transmission power control information for implementing a directive to a base station apparatus to increase or decrease transmission power so that a difference between said received SIR value and said target SIR value is eliminated.

A base station apparatus equipped with a transmission power control apparatus, said transmission power control apparatus comprising:

• measuring means for measuring a received SIR value which is a reception desired signal to interference ratio;
• setting means for setting a target SIR value decreased by a predetermined first value when received signal quality is better than a desired quality, or setting said target SIR value increased by a second value that is greater than said first value if received signal quality is poorer than said desired quality;
• and
• generating means for generating transmission power control information for implementing a directive to a mobile station apparatus to increase or decrease transmission power so that a difference between said received SIR value and said target SIR value is eliminated.

A transmission power control method comprising the steps of:

• measuring received data quality;
• updating a target SIR value by decreasing said target SIR value by a predetermined first value when said received data quality is better than a required quality, or by increasing said target SIR value by a second value that is greater than said first value when received data quality is poorer than said required quality;
• and
• directing an increase or decrease in transmission power at a communicating party so that a difference between this updated target SIR value and a received SIR value which is a reception desired signal power to interference power ratio is eliminated.