Transmission process and device for implementing the so-improved process

摘要

An improved split-band coder reduces signal-processing time, thereby reducing echo delay time and listener confusion. The voice-originated signal to be transmitted over a transmission line is sampled and digitally coded at a relatively high bit rate; the spectrum of said signal is then partitioned into p sub-bands. The sample stream of the signal so-filtered and partitioned into p sub-bands is split into blocks of samples, or portions, of a given time duration. A requantizing device proceeds for each block to the requantizing of the samples in each sub-band by means of requantizing parameters derived from the samples of the preceding sample block, whereas new requantizing parameters are determined and stored with a view to requantizing the following sample block. The requantized samples in the different sub-bands are multiplexed, and transmitted over the transmission line, together with the values of the highest amplitude samples in each sub-band.