Robust audio watermarking based on frequency-domain spread spectrum using CAZAC sequence

This paper presents a robust audio watermarking scheme based on spread spectrum in frequency domain using constant amplitude zero autocorrelation (CAZAC) sequence. First, the watermark bits are modulated by using M-ary phase shift keying (PSK), and then the modulated symbols are spread in phase by using the CAZAC sequence. At the extractor, the embedded information is recovered by despreading the phases of the watermarked audio. Experimental results show that the proposed scheme provides an adjustable payload, and is robust to most of the common signal processing and attacks while preserving the audio fidelity.