Performance Analysis of Finite-Sized Co-Operative Systems With Unreliable Backhauls

This paper presents a performance analysis of a finite-sized co-operative wireless system, where a group of transmitters with unreliable backhauls serve a desired receiver using noncoherent joint transmission. To facilitate analysis, an analytical expression for the distribution of the spatially averaged signal-to-interference-plus-noise ratio (SA-SINR) is derived in terms of key system and channel parameters. Leveraging the derived expression, the joint impact of node co-operation, backhaul reliability, interference, and communication range is investigated in the considered finite-sized co-operative system. Furthermore, based on the SA-SINR, closed form expressions for the average bit error rate (ABER) and average spectral efficiency (ASE) are derived. Further insights are established by analyzing the asymptotic performance in the high transmission power regime. From analytical derivations for the outage probability, ABER, and ASE and link-level simulations, it is verified that these asymptotic performance metrics are exclusively influenced by unreliable backhauls, so that the conventional diversity gains are not achievable.