Sub-band coder with a simple adaptive bit-allocation algorithm a possible candidate for digital mobile telephony?

A sub-band coder for speech digitization with adaptive bit-allocation is studied and described. It contains a uniform filterbank of thirteen 250 Hz channels. The sub-band amplitudes are quantized by the optimal method due to Max (8). Amplitudes in bands with no bits transmitted are regenerated by noise excitation with the respective sub-band power levels. Subjective test-results for bitrates from 4.8 to 16 kbits/s are included. Experiments with background noise and transmission bit-errors are cited.