The invention discloses a spectrum sensing
algorithm based on
variational mode decomposition, and solves the problem that a
signal at a receiving end is interfered by a
noise background in the prior art. The method comprises the following steps of: 1, generating a
simulation signal BPSK; 2, taking the mean value of the instantaneous frequencies of the components as a
decomposition parameter, determining an optimal mode
decomposition number K according to a change curve of the
decomposition parameter, and setting an appropriate
penalty factor alpha; 3, performing variational mode decompositionon the BPSK
signal according to the obtained decomposition parameters; 4, respectively carrying out power spectrum
estimation on the obtained L intrinsic
modes; 5, taking the ratio of the sum of the
spectral line intensities of the intrinsic
modes to the sum of intensities of all the intrinsic
modes as a test statistic; and 6, comparing the obtained test statistics with a judgment threshold, and making a final judgment. According to the method, the equivalent band-pass filtering characteristic and the Wiener filtering structure of
variational mode decomposition are utilized, frequency bands are better divided, and denoising
processing is better carried out; and compared with a traditional power spectrum segmented cancellation
algorithm, the
detection performance can be remarkably improved.