Waveform coding using time code multiplexing

A uniform amplitude sampler is presented as an alternative to uniform time-sampling systems. Time code multiplexing (TCM) consists of an encoder and a decoder. The encoder transmits the quantized time intervals corresponding to the time at which the input signal passed through uniformly spaced amplitude levels. The decoder reconstructs the signal by using a sin(x)/x convolution in the amplitude instead of time domain. Even though the channel bit stream is variable rate, TCM systems can be effectively used with the packet-switched voice/data networks of today's technology. The Nyquist rate which exists for the bandlimited uniform time-sampling systems has a parallel Nyquist rate for uniform amplitude-sampling systems. However, TCM offers the advantage of being able to change the input signal bandwidth and therefore the minimum required sampling rate, which is not easily accomplished with uniform time-sampling systems. TCM data results are discussed, showing SNR-versus-bit-rate performance. Audio recordings of computer simulations are presented for 8-, 16-, and 24-kbit/s systems.<>