Modulation in which a
signal is sampled, and the magnitude (with respect to a fixed reference) of each sample is quantized and digitized for
transmission over a common
transmission medium. (
188 )
Note 1: In conventional PCM, before being digitized, the
analog data may be processed (
e.g., compressed), but once digitized, the PCM signal is not subjected to further processing (
e.g., digital compaction) before being multiplexed into the aggregate
data stream.
Note 2: PCM
pulse trains may be interleaved with pulse trains from other channels.
