Performance of Suboptimum Feedback Functions for Sequential Detection Systems with Feedback

The performances of the optimum and several suboptimum feedback functions for sequential binary communication systems with a feedback link are evaluated and compared in terms of the error probability vs. normalized transmission rate characteristic. Evaluation is also made of nonsequential systems with optimum feedback functions. It is shown that the power advantage attained by the optimum system can be achieved without considerable loss by the suboptimum feedback functions.