Use of Coordinated Multipoint Transmission for Relaxation of Relay Link Bottlenecks

The emerging Long Term Evolution-Advanced (LTE-A) standard promises improvements in throughput and reduction in costs-per-bit, through use of techniques, such as, relaying and coordinated multipoint (CoMP) transmission and reception. The inherent self-backhauling of relays nodes makes them an attractive solution in areas where backhaul is either unavailable or costly. However, the performance of the backhaul relay link limits overall performance of relay systems, particularly for relays deployed in the cell edge. In this paper, we propose CoMP-enhancements in order to relax the relay link bottleneck. We study this proposed approach through system simulations of a selected realistic deployment scenario. The results demonstrate that use of a quantized co-phasing (QCP) CoMP technique provides significant signal- to-interference-plus- noise-ratio (SINR) gains and end-to-end throughput improvements for user equipment connected to the relays, even with simple scheduling techniques.