A lookup table generation method for a predistorter comprises sending a first single tone signal with a maximum expected amplitude to a channel simulation device including the power amplifier, estimating a closed loop gain and a closed loop phase of the power amplifier according to the first single tone signal and a first simulation output signal generated outputted by the channel simulation device, sending a plurality of single tone signals to the channel simulation device, each single tone signal having an amplitude different from all others of the plurality of single tone signals and lower than the maximum expected amplitude, generating a plurality of predistortion parameters according to the closed loop gain, the closed loop phase, the plurality of single tone signals and a plurality of simulation output signals outputted by the channel simulation device, and storing the plurality of predistortion parameters in a lookup table of the predistorter.