| 摘要 |
FIELD: technology for creating artificial interference for masking acoustic and electromagnetic information leakage channels. ^ SUBSTANCE: speech-like signal is composed of original signal being masked by modulation with noise signal of moments when signal being masked crosses zero. Modulation of zero crossing moments of speech signal may be performed by phase modulation of speech signal by noise signal. Modulation of zero crossing moments of speech signal may also be performed in accordance to a different algorithm - speech signal is clipped, resulting clipped signal is integrated, resulting saw-shaped signal is added to noise signal, after that resulting digital signal is clipped. For masking speech signal in digital form, resulting masking signal is added to the same signal converted to digital form. Modulating signal is a noise signal. Control listening indicates that resulting signal is unintelligible, although it preserves the speech-like form. ^ EFFECT: increased masking effect of speech-like noise signal. ^ 3 cl, 2 dwg |
