摘要 |
<p>A digital audio transmission system which is compatible with common carrier digital hierarchy systems converts two channels of analog data, such as precision stereo audio, into high resolution digital data words sampled at a high frequency. The data words are parity checked with the addition of one bit and divided into odd and even bit words for each channel. The bit words are time domain multiplexed into a common carrier frame with separate words for the parity bits and alternating channel data consisting of an odd and an even bit word. Each bit word is checked for all zeros and modified accordingly to assure that ones density and consecutive zero restraints are achieved. The resulting common carrier frames are transmitted over the appropriate common carrier cross-connects to a receiver which decodes the frames, recovering the bit and parity words. The bit words are recombined into data words and checked for parity. The data words are reconverted to the analog data, with valid data words being substituted for data words having a parity error. The analog data is sampled to divide it into the original two channels, resulting in a high precision recreation of the original analog data.</p> |