| 摘要 |
<p>A segment of a given signal is aligned with a corresponding reference segment by passing the reference segment through a full-wave rectifier (8), an anti-alias filter (10) and a first sampler (9), and storing the result in a first register (19). The output of the first sampler (9) is moreover passed through a second anti-alias filter (12) and a second sampler (13) which samples at a lower rate, and the result is stored in a second register (21). The given signal is then subjected to the same process with the exception that the output signals of the first (9) and second (13) samplers are passed continuously through first (23) and second (25) shift registers respectively until a correlator (40) indicates at least a predetermined degree of correlation between the contents of the second register (21) and the second shift register (25). A sliding correlation is then performed between the contents of the first register (19) and the first shift register (23) to determine the position of the correlation peak. The alignment process may be used when it is required to compare a segment of an audio signal recorded on a magnetic tape with the corresponding segment recorded on a master tape.</p> |
