SPECTRAL METHOD OF HOLOGRAPHIC NOISE-TOLERANT CODING
The article considers a spectral approach to noise-immune holographic coding based on the formation of a packet of orthogonal carriers with frequency shift keying. The encoded word is represented as a binary linear hologram. Single values of the hologram code determine the numbers of harmonics included in the carrier packet - group signal. The group signal is formed by summing the selected harmonics at the input of the transmitter amplifier or directly in the antenna. The signal is decoded in the receiver by calculating the spectrum of the received signal and applying an inverse holographic transformation to it, which restores the value of the transmitted data block. Spectral holographic coding provides a gain in noise immunity by 7-8 dB compared to holographic coding of the signal itself. Another advantage of the spectral code is the lower complexity of coding and decoding when the redundancy changes over a wide range, as well as high stealth due to the use of a noise-like signal.