Abstract: Provided is a transmission power control device and method calculating a compensated estimated signal-to-interference ratio (SIR) by subtracting an SIR margin according to change in the state of a receiving channel when measuring an estimated SIR of a reception signal at a receiving end, and determining an increase or decrease in transmission power according to a difference between the compensated estimated SIR and a target SIR, thereby providing a variable SIR margin threshold for TPC bit decision and preventing unnecessary cyclic redundancy check (CRC) errors and untimely change of the target SIR. Therefore, it is possible to efficiently reduce transmission and reception power consumption due to slow update of an existing target SIR, and to prevent a cyclic redundancy check (CRC) error caused by the untimely change of the target SIR.

Abstract: Provided is a wireless packet communication method, and more particularly, a method and apparatus for enabling low-power communication by providing separate driving clocks optimized for a lower part for performing the function of a physical layer part and an upper part for performing the function of an upper layer above the physical layer in a wireless packet communication system. The method includes a first clock providing step of measuring actual data transmission and reception rates at a predetermined period, setting up a frequency (F1) of a first clock based on the measured rates, and providing the first clock to the upper part and a second clock providing step of determining a transfer mode of the wireless packet communication system, detecting a frequency (F2) of a second clock selected according to the determined transfer mode, and providing the second clock to the lower part.