公开(公告)号：US5319735A

公开(公告)日：1994-06-07

申请号：US808913

申请日：1991-12-17

申请人： Robert D. Preuss ,  Salim E. Roukos ,  A. W. F. Huggins ,  Herbert Gish ,  Marcos A. Bergamo ,  Patrick M. Peterson ,  Alan G. Derr

发明人： Robert D. Preuss ,  Salim E. Roukos ,  A. W. F. Huggins ,  Herbert Gish ,  Marcos A. Bergamo ,  Patrick M. Peterson ,  Alan G. Derr

IPC分类号： G10L19/00 ,  G11B20/00 ,  G11B20/10 ,  G11B20/18 ,  H03M5/04 ,  H04B1/66 ,  H04B1/707 ,  H04L5/00 ,  H04N5/92 ,  G10L3/00

CPC分类号： G11B20/00913 ,  G10L19/018 ,  G11B20/00086 ,  G11B20/10009 ,  G11B20/10527 ,  G11B20/1813 ,  H03M5/04 ,  H04B1/665 ,  H04B1/707

摘要： A code signal representing a sequence of code symbols carrying digital information is generated with the frequency components of the code signal being essentially confined to a preselected signalling band lying within the bandwidth of an audio signal within which the code signal is to be embedded. The audio signal is continuously frequency analyzed over a frequency band encompassing the signalling band and the code signal is dynamically filtered as a function of the analysis thereby to provide a modified code signal with frequency components which are, at each time instant, essentially a preselected small proportion of the levels of the corresponding audio signal frequency components. Accordingly, the modified code signal can be combined with the audio signal to obtain a composite audio signal which is not readily distinguishable from the original audio signal by listening. Furthermore, the digital information can be recovered from the composite audio signal by a procedure which is essentially the compliment of that used to obtain the composite audio signal.

摘要翻译： 产生代表携带数字信息的码元序列的代码信号，其中代码信号的频率分量基本上被限制在位于要嵌入代码信号的音频信号的带宽内的预选信令频带。 音频信号在包围信令频带的频带上被连续频率分析，并且代码信号作为分析的函数被动态滤波，从而提供具有频率分量的修改的码信号，频率分量基本上是预选小的 相应音频信号频率分量的比例。 因此，可以将修改的代码信号与音频信号组合以获得不容易通过收听与原始音频信号区分的复合音频信号。 此外，可以通过本质上是用于获得复合音频信号的补充的过程从复合音频信号中恢复数字信息。