In references [1, 2], triple multipulse position modulated (TPPM) signaling has been introduced as a very reliable format for optical communication channels. In this article, such a multipulse model is extended to the Steiner quadruple pulse system (SQS). Considering a threshold demodulation scheme for a fully degraded optical channel, performance of the Reed-Solomon coded model is evaluated and ... [Show full abstract] compared to the standard coded PPM, when similar information efficiency and closest bandwidth expansion are allowed. The gained results are very interesting. © 1992 John Wiley & Sons, Inc.