Informed algorithms for watermark and synchronization signal embedding in audio signal

This work presents audio watermarking algorithms robust to D/A and A/D conversion, scaling and quantization noise. The watermark is embedded in log-spectrum domain using a differential scheme and a quaternary bi-orthogonal code. An informed embedding algorithm is proposed, minimizing bit error rate while keeping distortion level below the masking threshold. An informed coding scheme, based on Costa´s approach, is also used. Synchronization is based on two pilot signals, and the informed synchronization scheme is proposed, in order to speed up a synchronization process.