Modulation and demodulation for probabilistic coding

Research in coding theory has resulted in the determination of bounds, as a function of the rate of communication, on the probability of error that can be attained over a memoryless transmission facility. These results are reviewed, and their implication with regard to the evaluation of modulation and demodulation systems is discussed. The objective is to describe some of the interrelations that affect the performance of a communication system used with probabilistic coding.