Use of coordinated multipoint transmission /reception for enhanced backhauling in nomadic relay

One of the promising enhanced features introduced in LTE-Advanced is relaying. Coverage extensions as well as enhanced throughput gain are attractive from the perspective of network operators. While functioning in the macro-overlaid network, relay offers the flexibility of random deployment (nomadic relay) at places where the communication link is congested due to an occasional event (e.g. festival) or in the emergency response scenario. This nomadic relay deployment helps to improve coverage and capacity in targeted areas based on a temporary but immediate demand. However, peak achievable throughput at the access link is limited by the backhaul link rate. The backhaul link become a bottleneck if the aggregated access link throughput exceeds the backhaul link rate. To avoid this bottleneck, it is desirable to identify means to maintain the backhaul link rate above the aggregated access link capacity. To that end, another promising technology is Coordinated Multipoint Transmission/Reception (COMP) where joint transmission from multiple base station or coordinated base stations offer enhanced throughput. In this study, two types of COMP technique namely Dynamic Point Blanking (DPB) and Quantized Co-Phasing (QCP) have been applied at relay backhaul to reduce the impact of the backhaul bottleneck. This study is performed through analyzing two case scenarios such as 3GPP 5×5 building grid model and realistic building layout. Finally, it is shown that Inter-QCP provides the best output in both cases (3GPP and realistic building layout) at the backhaul link and access link.