SINR Balancing Techniques in Coordinated Multi-Cell Downlink Systems

• Published in: IEEE transactions on wireless communications Vol. 12; no. 2; pp. 626 - 635
• Main Authors: PARK, Haewook, PARK, Seok-Hwan, KIM, Jin-Sung, LEE, Inkyu
• Format: Journal Article
• Language: English
• Published: New York, NY IEEE 01-02-2013; Institute of Electrical and Electronics Engineers
• Subjects: Antennas; Applied sciences; Array signal processing; Detection, estimation, filtering, equalization, prediction; Downlink; Exact sciences and technology; Information, signal and communications theory; Interference channel; Interference channels; multi-cell systems; Optimization; Radiocommunications; Signal and communications theory; Signal to noise ratio; Signal, noise; SINR balancing; Switching and signalling; Systems, networks and services of telecommunications; Telecommunications; Telecommunications and information theory; Transmission and modulation (techniques and equipments); Wireless communication; Performance evaluation; Parameter estimation; Optimal algorithm; Base station; Downlink; Signalling; Interference channel; SINR balancing; multi-cell systems; Simulation; Channel estimation; Residual impurity; Multiple system; SISO system; Signal to interference plus noise ratio; Antenna; Signal to noise ratio
• ISSN: 1536-1276; 1558-2248
• DOI: 10.1109/TWC.2012.122212.111962

In this paper, we study coordinated multi-cell downlink systems where multiple base stations jointly design a transmission strategy by sharing channel state information. Particularly, we tackle the signal-to-interference-plus-noise ratio (SINR) balancing problem to maximize the worst-user rate. We consider single-input single-output (SISO) interference channels (IFC) where all nodes are equipped with a single antenna, and there is one active user in each cell. First, achievable rate regions with symmetric complex (SC) and asymmetric complex (AC) signaling techniques are investigated. Then, we present the optimal and near-optimal SINR balancing algorithms with the SC signaling for two and three user SISO IFC. Due to residual interference, the worst-user rate of the SC signaling is saturated at high signal-to-noise-ratio region. To alleviate this problem, we also propose efficient balancing schemes based on the AC signaling for both two and three-user cases. Simulation results confirm effectiveness of the proposed SINR balancing algorithms and show that a substantial gain of the AC signaling is achieved over the SC signaling in terms of the maximum worst-user rate.