Performance of Co-Operative Uplink Reception with Non-Ideal Backhaul

In this paper, we consider the problem of uplink coordinated multi-point (UL CoMP) in a wireless network with non-ideal backhaul links. UL CoMP with joint receivers has the potential to improve both cell-edge and system capacity depending on the deployment environment. Realizing the performance gains from CoMP requires ideally large bandwidth and low-latency backhaul links to do data exchange. Even if backhaul bandwidth is well-provisioned, latencies in the backhaul data exchange protocols could lead to severe performance degradation due to the requirement of strict Ack/Nack timing imposed by the LTE standard [1]. In order to deal with this issue, we propose strategies for adaptive helper cell management in order to entail minimal performance loss across different loading conditions. Using system simulations and detailed performance analysis, we show the advantage of using the proposed approaches with a finite buffer traffic model for a heterogeneous network deployment scenario including a Macro-cell layer and a clustered small-cell layer.