Abstract :
In this research paper, we consider some aspects of the general problem of encoding and decoding for time-discrete, amplitude-continuous memoryless channels. A scheme for constructing a discrete signal space, for which sequential encoding-decoding methods are possible for the general continuous memoryless channel, is described. Random code selection from a finite ensemble, with each code word sequentially generated from a small number of basic waveforms, is considered. The effects of these signal-space constraints on the average probability of error, for different signal-power constraints, are also discussed. The application of sequential decoding to the continuous asymmetric channel, and a new decoding scheme for convolutional codes, successive decoding, are considered. This new decoding scheme yields a tighter bound on the average number of decoding computations for asymmetric channels than has yet been obtained for sequential decoding. The probabilities of error of the two decoding schemes are also discussed. We consider the quantization at the receiver, and its effects on probability of error and receiver complexity.
