Coordinated 3D Beamforming for Interference Management in Cellular Networks
Artikel i vetenskaplig tidskrift, 2014

We consider downlink transmission in a cellular network consisting of multi-antenna base stations (BSs), single-antenna mobile users, directional antennas each with a vertically adjustable beam, and control signaling delays in feedback and backhaul links. We propose a novel transmission technique in which intercell interference management is performed via coordinating the beamforming jointly in the horizontal and vertical planes of the wireless channel, denoted as coordinated 3D beamforming. In the horizontal plane, we focus on intercell interference cancelation (ICIC) and investigate its performance when the provided channel state information (CSI) is impaired due to delay/mobility. It is demonstrated that the superiority of ICIC over conventional intracell maximum ratio transmission is highly dependent on the CSI accuracy. In the vertical plane, we consider intercell interference control via coordinatively adapting the elevation angle of the BS antenna pattern, denoted as tilt, to the locations of the scheduled users. It is shown that with perfect CSI interference management should be performed in the horizontal plane using ICIC, while at high delay/mobility it should be done in the vertical plane via coordinated tilt adaptation. For intermediate values of delay/mobility, joint interference management in both planes is required.

Antenna tilt

channel state information (CSI) delay

base station coordination

3D beamforming

interference management


Nima Seifi

Telefonaktiebolaget LM Ericsson

J. Zhang

Hong Kong University of Science and Technology

Robert W. Heath Jr.

University of Texas at Austin

Tommy Svensson

Signaler och system, Kommunikationssystem, informationsteori och antenner, Kommunikationssystem

Mikael Coldrey

Ericsson Sweden

IEEE Transactions on Wireless Communications

1536-1276 (ISSN)

Vol. 13 5396-5410