Rate-Distortion and Outage Probability Analyses for Single Helper Assisted Lossy Communications

The primary objective of this paper is to investigate the performance improvement provided by a helper, with the aim of applications to a lossy communication system in wireless sensor networks (WSNs) and/or Internet of Things (IoT). Initially, we formulate the system model as a problem of multiterminal source coding with a helper, and determine an inner bound on the achievable rate-distortion region for binary sources. Based on Shannon's lossy source-channel separation theorem, we further derive the outage probability of the system over block Rayleigh fading channels. The numerical results indicate that a helper can obviously expand the achievable rate-distortion region and provide diversity gains which in turn decrease the outage probability. Finally, we evaluate the practical performance of outage probability through simulations with exclusive-or (XOR) as an example of the helper structure. Both the simulation and theoretical results show second order diversity by introducing a helper, and lower outage probability by increasing the acceptable distortions.