基于OFDM信号循环前缀的数字水印技术

Based on OFDM, this paper presents a watermarking algorithm in wireless multi-path channel. Before the carrier is transmitted, the watermark is applied one-to-one to the cyclic prefix of OFDM signals. At the receiver, the watermark can be extracted blindly by comparing the difference between the average time offset over multiple OFDM symbols and the tracking algorithm estimate of the time offset of each individual OFDM symbol. Experimental results prove that the watermark algorithm is robust to multi- path time delay in the wireless channel.