Covert Mimicry Communication using Humpback Whale Song

Mimicry communication is an innovative approach for covert communication in underwater acoustic environment. Its demand is increasing rapidly for military, defense and underwater marine operations. The aim is to communicate clandestinely keeping the information and location of transducers furtive. The communication signal is made analogous to the real ocean noise. The signal can be detected by intruder but it is excluded from the process of recognition due to natural sound signature. It gives excellent Low Probability of Recognition characteristics. We have presented an inimitable way for covert underwater acoustic communication by mimicking of humpback whale song. The structure of mimicked signal is akin to cetacean sound and covert data is modulated in it. We have used two unique techniques to hide data in sea mammal vocal. The song segments are shuffled using M-ary technique and time interval between the song segments is varied using Pulse Position modulation. This variation in real humpback whale song represents the covert information bits with maximum imperceptibility. At the receiver, the communication signal is correlated to extract the position of song segments and pulse delay is calculated. BER are less than 10
^-2
through simulation result at SNR down to 0dB with perfect covert and stealthy perspective.