EXACT EXPRESSION FOR PRABHU UPPER BOUND FOR DIGITAL-COMMUNICATION SYSTEMS WITH NOISE AND INTERFERENCE

The authors first present an exact expression for the Prabhu general u pper bound on error probability of the canonical binary system with no ise and interference in terms of a modified Bessel function. This boun d is tighter than the modified Chernoff bound and simpler than a recen t approximation. Secondly, the new expression is used to evaluate the error rate of an optically preamplified direct-detection optical recei ver and is shown to provide tighter estimates of the error probability than either the Chernoff or modified Chernoff bounds for amplifier ga ins of practical interest.