The rate of transmission of information in pulse-code-modulation systems

A general expression is obtained for the maximum rate of communication of information in pulse-code modulation systems using any scale of numbers, when the interfering noise has a Gaussian amplitude distribution. The particular cases of binary and tertiary coding are dealt with in more detail, and a comparison is made between the communication rate R and the ideal channel capacity C. It is shown that for both systems the communication efficiency R/C reaches a maximum of the order of 80% at particular signal/noise ratios. It is also shown that in all systems, regardless of the scale of numbers used, the communication efficiency tends to 63.6% as the signal/noise ratio tends to zero.