| 摘要 |
A system and method for processing relatively high fidelity audio signals (having components in the high, intermediate and low frequency ranges, such as speech and music signals having frequencies between about 50 c.p.s. and 6,000 c.p.s., for example) for transmission across relatively low fidelity transmission channels e.g., telephone lines or radio frequency carrier waves which are restricted to low fidelity signal modulation) adapted to effectively transmit only electrical signal components in an intermediate frequency range e.g., from about 300 c.p.s. to about 4,000 c.p.s., for example). Typical practice of the invention involves isolation of the signal components in the intermediate frequency range for transmission on one one such low fidelity channel, and isolation of the signal components in high and low frequency to derive non-overlapping, frequency-displaced signals in the intermediate frequency range. These frequency-displaced signals are thereafter transmitted on a second such low fidelity transmission channel. At the receiving location, the frequency-displaced signals are converted to their original high and low frequency components and combined with the intermediate frequency components to substantially re-establish the original audio signal.
|
