A theoretical model for time code modulation

The traditional waveform coding techniques for digital communication systems convert the original analog input signal into a digital bit stream using uniform sampling in the time domain, i.e., PCM, DM, ADPCM. In this paper we propose the Time Code Modulation (TCM) technique as an alternative coding scheme, where information is extracted from the signal, only at the time instants when necessary. This results in a variable sampling rate, where its mean value is significantly less than the Nyquist rate. In addition we suggest a general theoretical model for TCM and we present simulation results for various implementations of TCM coders and decoders. A theoretical estimation of SNR vs. sampling rate performance is also presented.