Base station and signal processing method

A base station includes a memory, a processor, a radio frequency circuit, and an input and output circuit. The processor is coupled to the memory for reading at least one computer program to perform several operations, including: generating digital signals at the physical layer; estimating a sampling parameter value and an inserting parameter value; performing an interpolation finite impulse response filter process to the digital signal of the physical layer according to the sampling parameter value and the inserting parameter value to generate a first sub signal. The radio frequency circuit is configured to perform a masking filter process according to a masking filter cutoff frequency to the first sub signal to generate a second sub signal, to convert the second sub signal into an analog signal, and to generate an output signal according to the analog signal. The input and output circuit is configured to transmit the output signal.