Patent ID: 7738902

Claim:
A transmission power control method in a wireless communication system for comparing a measured error rate and a required error rate, updating a target quality based upon the result of the comparison and controlling transmission power on a transmitting side in such a manner that measured quality will agree with the target quality, comprising the steps of: measuring Cyclic Redundancy Code (CRC) error of each transport block (TrBk) included in a receive signal over a fixed period of time repeatedly; calculating Block Error Rate (BLER) for each fixed period of time; judging that degradation in quality of a receive signal occurs continuously when the calculated BLER is larger than a set value; detecting a state as a high quality state in which BLER is calculated over the fixed period of time and all receive signals are found to be CRC OK over the fixed period of time; setting said target quality to an initial value when the high quality state is detected continuously after the degradation in quality has been occurring continuously; and reducing the target quality by a prescribed amount from the initial value if no CRC error is detected whenever an error detection check of each TrBK is made and, when a CRC error has been detected, thenceforth measuring error rate at a target-quality update period that conforms to service quality, comparing the measured error rate and a required error rate and updating the target quality based upon a result of the comparison.