A processing method for an orthogonal frequency division multiplexing, OFDM, signal, wherein the processing method comprises: multiplying, in a digital domain, a generated OFDM signal by a simple harmonic wave whose frequency is fs to obtain a frequency shifted OFDM signal; performing digital-to-analog conversion on the frequency shifted OFDM signal to obtain an OFDM signal after the digital-to-analog conversion; amplifying the OFDM signal after the digital-to-analog conversion by using a driver, to obtain an amplified OFDM signal; and modulating the amplified OFDM signal by using a modulator and sending a modulated OFDM signal, wherein fs is equal to Δf/n, n is an integer greater than 1, and Δf is a frequency difference between two adjacent subcarriers for the obtained OFDM signal, wherein before the multiplying, in a digital domain, the generated OFDM signal by the simple harmonic wave whose frequency is fs, the processing method further comprises: mapping to-be-sent binary data to obtain constellation point data; performing serial-to-parallel conversion on the constellation point data to obtain arranged constellation point data; performing inverse fast Fourier transform, IFFT, on the arranged constellation point data to obtain a time-domain signal; and performing parallel-to-serial conversion on the time-domain signal to obtain an arranged time-domain signal, and obtaining the generated OFDM signal by performing a step of adding a cyclic prefix to the arranged time-domain signal. multiplying, in a digital domain, a generated OFDM signal by a simple harmonic wave whose frequency is fs to obtain a frequency shifted OFDM signal; performing digital-to-analog conversion on the frequency shifted OFDM signal to obtain an OFDM signal after the digital-to-analog conversion; amplifying the OFDM signal after the digital-to-analog conversion by using a driver, to obtain an amplified OFDM signal; and modulating the amplified OFDM signal by using a modulator and sending a modulated OFDM signal, wherein fs is equal to Δf/n, n is an integer greater than 1, and Δf is a frequency difference between two adjacent subcarriers for the obtained OFDM signal, wherein before the multiplying, in a digital domain, the generated OFDM signal by the simple harmonic wave whose frequency is fs, the processing method further comprises: mapping to-be-sent binary data to obtain constellation point data; performing serial-to-parallel conversion on the constellation point data to obtain arranged constellation point data; performing inverse fast Fourier transform, IFFT, on the arranged constellation point data to obtain a time-domain signal; and performing parallel-to-serial conversion on the time-domain signal to obtain an arranged time-domain signal, and obtaining the generated OFDM signal by performing a step of adding a cyclic prefix to the arranged time-domain signal. mapping to-be-sent binary data to obtain constellation point data; performing serial-to-parallel conversion on the constellation point data to obtain arranged constellation point data; performing inverse fast Fourier transform, IFFT, on the arranged constellation point data to obtain a time-domain signal; and performing parallel-to-serial conversion on the time-domain signal to obtain an arranged time-domain signal, and obtaining the generated OFDM signal by performing a step of adding a cyclic prefix to the arranged time-domain signal.