Saddlepoint approximations of lower and upper bounds to the error probability in channel coding

This paper has been presented at: 52nd Annual Conference on Information Sciences and Systems (CISS)Saddlepoint approximations of the meta-converse and random-coding union bounds are derived. These bounds accurately characterize the channel coding minimum error probability for symmetric memoryless channels in a wide range of system parameters. The proposed approximations are simple to compute and yield a unified analysis of both hypothesis-testing lower bounds and random-coding upper bounds.This work has been funded in part by the European Research Council under ERC grant agreement 725411, by the Spanish Ministry of Economy and Competitiveness under grants TEC2013-41718-R, FJCI-2014-22747, IJCI-2015-27020, and TEC2016-78434-C3 (AEI/FEDER, EU), and by the Spanish Ministry of Education, Culture and Sport under grant FPU14/01274