Resource Allocation, Transmission Coordination and User Association in Heterogeneous Networks: A Flow-Based Unified Approach

In this paper, we formulate a flow-based framework for the joint optimization of resource allocation, transmission coordination, and user association in a heterogeneous network comprising of a macro base station and a set of pico base stations and/or relay nodes. By incorporating these three important network processes together and by unifying the analysis of pico base stations and relay nodes, our framework can act as an important engineering tool for understanding the performance of different configurations. We use the resulting formulations to characterize the performance of different combinations of resource allocation schemes and transmission coordination mechanisms. We obtained important engineering insights regarding the interplay of these network processes. In particular, under the deployment of pico base stations, we find that partially shared deployment outperforms the co-channel deployment, with or without transmission coordination. In contrast, the results also show that the deployment of relay nodes does not offer meaningful throughput gains for any choice of resource allocation scheme or transmission coordination mechanism.