Access authentication method based on power line channel fingerprint

The invention discloses an access authentication method based on a power line channel fingerprint, which comprises the following steps of: extracting an electric signal sent by subcarrier equipment, performing frequency domain transformation on the electric signal, and sequencing the obtained amplitudes and phases in sequence according to the magnitude of frequency to form an n-dimensional phase characteristic fingerprint vector, namely a characteristic fingerprint of the subcarrier equipment; taking the serial number of the collected subcarrier equipment as the mark number of the characteristic fingerprint, and finally integrating to obtain an equipment fingerprint database of the power bus system; when the identity of the equipment is identified and authenticated, performing frequency domain transformation on a signal sent by the to-be-identified equipment, and forming an n-dimensional phase fingerprint feature vector; and comparing the n-dimensional feature vector with a fingerprint vector of a correspondi