OFDM-based audio watermarking for electronic radiotelephone identification

The algorithm of high capacity digital watermarks embedding into the speech signals using OFDM-technology has been worked out. For DWM embedding it is suggested to apply vector quantization of complex envelope of the narrow-band signal. DWM resistance against intersymbol interference, multiplicative and additive interferences are provided accordingly by means of: 1) OFDM-like forming the narrow-band channels, 2) quantization step adaptation in the transmitter and receiver, and 3) spreading of one bit DWM energy along L samples. The algorithm allows realization of automatic identification of radiotelephone transmissions without replacing standard radio installation and changing operational radiotelephony procedures.