Abstract: Audio information hiding algorithm based on spread spectrum is generally detected by correlation threshold, but the orthogonal of pseudorandom sequence is always destroyed by perception reshaping. In order to reduce the correlation noise induced by original signal, this paper analyzed the statistical characteristics of audio signal, pseudorandom sequence and channel, and derived the mathematical expectation and variance, and gave out the connection of these parameters. Finally, the results from the simulation and experiment prove that these expressions are correct.

Key words: spread spectrum, audio information hiding, audio signal, pseudorandom sequence

摘要： 基于扩频的音频隐藏算法一般都采用阈值相关法进行检测，但感知整形过程往往会破坏伪随机序列的正交性。为削弱盲提取时原始载体信号所导致相关噪声的影响，通过分析音频信号、伪随机序列和信道的统计特性，推导出接收信号的数学期望和方差，并给出了正确检测时各参数间的约束关系。最后，通过仿真实验验证了以上结论的正确性。

关键词: 扩频, 音频信息隐藏, 音频信号, 伪随机序列