Joint Precoding and Load Balancing Optimization for Energy-Efficient Heterogeneous Networks
Artikel i vetenskaplig tidskrift, 2015

This paper considers a downlink heterogeneous network, where different types of multiantenna base stations (BSs) communicate with a number of single-antenna users. Multiple BSs can serve the users by spatial multiflow transmission techniques. Assuming imperfect channel state information at both BSs and users, the precoding, load balancing, and BS operation mode are jointly optimized for improving the network energy efficiency. We minimize the weighted total power consumption while satisfying quality-of-service constraints at the users. This problem is nonconvex, but we prove that for each BS mode combination, the considered problem has a hidden convexity structure. Thus, the optimal solution is obtained by an exhaustive search over all possible BS mode combinations. Furthermore, by iterative convex approximations of the nonconvex objective function, a heuristic algorithm is proposed to obtain a suboptimal solution of low complexity. We show that although multicell joint transmission is allowed, in most cases, it is optimal for each user to be served by a single BS. The optimal BS association condition is parameterized, which reveals how it is impacted by different system parameters. Simulation results indicate that putting a BS into sleep mode by proper load balancing is an important solution for energy savings.

heterogeneous networks

load balancing

precoding design

Energy efficiency

Författare

Jingya Li

Chalmers, Signaler och system, Kommunikationssystem, informationsteori och antenner, Kommunikationssystem

E. Bjornson

SUPELEC Campus de Gif

Linköpings universitet

Kungliga Tekniska Högskolan (KTH)

Tommy Svensson

Chalmers, Signaler och system, Kommunikationssystem, informationsteori och antenner, Kommunikationssystem

Thomas Eriksson

Chalmers, Signaler och system, Kommunikationssystem, informationsteori och antenner, Kommunikationssystem

M. Debbah

CentraleSupelec

IEEE Transactions on Wireless Communications

1536-1276 (ISSN)

Vol. 14 10 5810-5822

Mobile and wireless communications Enablers for Twenty-twenty (2020) Information Society (METIS)

Europeiska kommissionen (FP7), 2012-11-01 -- 2015-04-30.

Ämneskategorier

Telekommunikation

Kommunikationssystem

DOI

10.1109/twc.2015.2443044