To meet the growing capacity demands in cellular networks by mobile application users, several advanced technologies of increased complexity have recently emerged for wireless access. Most prominently, these tap on the increased number of degrees of freedom made available by the combined use of multiple antennas in several neighbouring cell sites. However, such cooperative / coordinated wireless access schemes remain of largely theoretical value due to the excessive needs of data sharing between different sites and the need for additional antennas, which is impractical due to many hardware and cost constraints. In HARP, we plan to bring distributed multi-antenna wireless access to reality by combining two powerful emerging technologies:
- radio remote heads (RRHs), which allow for widely geographically distributed access via radio-over-fibre connections to a central base station; and
- electronically steerable passive array radiators (ESPARs), which provide multi-antenna-like functionality with a single active RF chain only
The proposed combined network design concept is expected to yield the benefits of high capacity multi-antenna multi-cell cooperative wireless access while doing so in a realistic, low-cost and, equally importantly, environmentally-friendly manner.