Comparison of sequential and nonsequential detection systems with uncertainty feedback

In a previous paper, we found optimal signals for, and evaluated the performance of, a binary sequential detection system in which the detector constantly feeds back to the transmitter its "state of uncertainty" concerning what is being sent. In the present paper, we consider a similar system, which uses a nonsequential detector. Comparison of the results of the two papers shows that: 1) when the prescribed peak-to-average power ratio is small, the sequential system operates with a -dB average-power advantage over the nonsequential system; 2) when the prescribed peak-to-average power ratio is large, the sequential system operates with a -dB peak-power advantage over the nonsequential system. In both systems, the performance improves rapidly as the peak-power constraint is relaxed, i.e., as the prescribed peak-to-average power ratio is increased.