Semi-Distributed Power and Subcarrier Allocation in LTE Hetnet System

Abstract

In order to provide the large coverage and high data rate in future system, more and more low power nodes (LPNs) e.g., pico nodes, relay nodes, etc., are introduced into the LTE heterogeneous network (HetNet). The resource allocation and optimization scheme is the key issue in Hetnet system since the interference environment is quite complicated compared with the traditional homogenous networks. In this paper, the semi-distributed power and subcarrier allocation scheme is proposed, which aims to achieve the good performance tradeoff between the macro eNBs and the pico nodes. One novel utility function is investigated taking both macro edge UEs and pico edge UEs into account based on limited average data rate information exchanges between macro eNB and pico eNBs. The interference for the edge UEs can be coordinated efficiently due to the dynamic power and subcarrier allocations. Compared with the proportional fairness (PF) scheduling algorithm, the simulation results show that the proposed semi-distributed scheme can achieve about 8% throughput gain in average cell throughput. Furthermore, the pico edge UEs, and macro edge UEs of the proposed scheme can achieve 17%, 12% capacity gain, respectively.