功放无记忆模型，主要是根据给定的运放输入输出信号建立功放无记忆模型（幂级数形式），并根据nmse参数选取了最佳幂级数阶数(The memoryless model of the power amplifier is based on the given input and output signals of the operational amplifier. The memoryless model (power series form) of the power amplifier is e