The invention relates to an orthogonal frequency division multiplexing filling type cognitive system master user signal blind estimation method based on fast Fourier transform. The method comprises the following steps: firstly, carrying out modeling analysis on an OFDM-based filled cognitive system, and estimating a frequency interval between OFDM subcarriers, a time length of a single symbol anda time length of a cyclic prefix based on autocorrelation function characteristics; secondly, according to the characteristics of the fast Fourier transform, calculating the order and sampling frequency of the fast Fourier transform; estimating the number of sub-bands by applying a maximum likelihood method and a dynamic planning method; and finally obtaining the main parameters of the OFDM main signal: the duration of the information data, the length of the cyclic prefix, the length of the OFDM symbol, the carrier frequency and the number of subcarriers. The method is simple in algorithm, lowin resource requirement and suitable for being used on user equipment with low power consumption requirement.
Orthogonal frequency division multiplexing filling type cognitive system master user signal blind estimation method based on fast Fourier transform