An underwater target identification friend or foe method based on voiceprint marker of ship

In order to improve the identification friend or foe (IFF) ability of underwater weapon, an underwater target IFF method based on voiceprint marker of ship was proposed. It codes the error correction for appointed secret information and uses fast chaotic frequency hopping (FH) to take the information hiding of first stage. It also selects the working frequency band within the range of main frequency band of ship-radiated noise. The spectrum of FH signal is linear in a short time. The ship-radiated noise can be regarded as the cover-information of FH signal to take the information hiding of second stage, which forms a voiceprint marker of ship. Friend will be identified according to the voiceprint marker of ship. The simulation results show that in the background of strong ship radiated noise and underwater acoustic multipath, the bit error rate of FH signal based on the suggested method is below 10^-6 when SIR = -10dB and SNR > -4dB. The reservoir test of 3km results show that it could attain the correct IFF. Because it is expressed as a covert signal, the enemy can't detect it. The numerical simulation and lake test results show that the IFF method proposed is simple and flexible, and has fast identification speed, high identification rate and the performance of concealment and anti-interception.