Performance of Opportunistic Fixed Gain Bidirectional Relaying With Outdated CSI

TL;DR

This paper analyzes how outdated channel state information affects the performance of bidirectional relaying with fixed gain, revealing that relay placement and outdated CSI significantly influence network reliability.

Contribution

It provides closed-form expressions for outage probability, MGF, and SER in the context of outdated CSI, and investigates relay placement effects on performance.

Findings

Adding relays does not improve performance with substantially outdated channels

Performance can be enhanced by positioning relays closer to the source with outdated channels

Analytical results are validated through simulations

Abstract

This paper studies the impact of using outdated channel state information for relay selection on the performance of a network where two sources communicate with each other via fixed-gain amplifyand- forward relays. For a Rayleigh faded channel, closed-form expressions for the outage probability, moment generating function and symbol error rate are derived. Simulations results are also presented to corroborate the derived analytical results. It is shown that adding relays does not improve the performance if the channel is substantially outdated. Furthermore, relay location is also taken into consideration and it is shown that the performance can be improved by placing the relay closer to the source whose channel is more outdated.