Transmission power control method in asymmetric digital subscriber line system

摘要

A transmission power control method in an Asymmetric Digital Subscriber Line (ADSL) system for transmitting data through a telephone line interposed between an ADSL-TUC (Transmission Unit Center) and an ADSL-TUR (Transmission Unit Remote). The ADSL system compares a noise margin with a reference value and reduces a transmission power level of a transmission signal step-by-step, beginning from an initial maximum power level. When the transmission power level is reduced to the point that the noise margin no longer exceeds the reference value, the transmission power level is then restored to a level just high enough that the noise margin is greater than the reference value. As a result crosstalk is minimized while permitting optimum data transmission rates and saving transmission power.