The signal processing and simulation on the baseband and Intermediate Frequency (IF) signals of the airborne equipment of the radio short-range navigation system are proposed. The baseband pulse signal is generated mainly by Matlab software and the IF signal is generated through amplitude modulation. The bandwidth of the IF signal is calculated using the Channel Measurement tool of the Simulink spectrum analyzer. Based on the bandwidth parameter, an IF signal demodulation module is designed. The demodulation of the received pulse signal is achieved through band-pass filtering, coherent demodulation, and low-pass filtering. The transmission baseband pulse generation is realized based on the built-in Random Access Memory (RAM) of the Field Programmable Gate Array (FPGA). The signal modulation and demodulation methods are verified completely and correctly through the above processes.