The present disclosure provides a method for configuring a communication system with a variable attenuator. The method includes measuring a first attenuation accuracy of the communication system at a first attenuation rate of the variable attenuator, and setting the variable attenuator based on the first attenuation accuracy so that the variable attenuator has a second attenuation rate and the communication system has a second attenuation accuracy. The method further includes obtaining a plurality of first gains at first temperatures and first frequencies, and performing an interpolation process to obtain, from the plurality of first gains, a plurality of second gains at second temperatures and/or second frequencies. The method also includes building a three-dimensional gain table with respect to the temperature, the frequency and the attenuation rate.