An adaptive method to increase the S/N ratio of a digital signal by biased distribution of bit energy

This method is based on the fact that if noise affects the waveform representing a bit of a binary signal it causes a change in value of the bit and hence causes an error. However if it is to affect the lesser significant bits, the error is lower than when it inflicts an error in one of the more significant bits. The probability of the noise inflicting an error in a bit is a function of the energy of the waveform representing that bit. Hence a maximum increase in signal to error ratio can be achieved if the energy of the bit waveforms is optimally varied according to the order of significance of the bits such that the word energy and word time is conserved.