This paper examines a novel multichannel multi-antenna-based cross-tier interference coordination strategy for two-tier femtocell networks. To reduce the cross-tier interference and improve the aggregate throughput of two-tier femtocell networks without exchanging feedback information by backhauling, we propose a beamforming codebook restriction strategy. The beamforming codebook restriction strategy enables the femtocell users to select the best channel that is robust to cross-tier interference before the transmission by reducing the size of the macrocell beamforming codebook. Although restricting the beamforming codebook increases the quantization error for macrocell users, the opportunistic channel selection strategy and the proportional fair scheduler compensate for the increased quantization error by exploiting the channel selection diversity gain and the multiuser diversity gain. Both analytical and numerical results demonstrate that the proposed strategies collaboratively improve the aggregate throughput of two-tier femtocell networks.
Bibliographical noteFunding Information:
Manuscript received December 17, 2009; revised June 17, 2010 and October 08, 2010; accepted January 10, 2011. Date of publication February 17, 2011; date of current version May 16, 2011. This work was supported in part by the Korea Science and Engineering Foundation through the National Research Laboratory (NRL) Program under Grant R0A-2007-000-20043-0 and in part by The Ministry of Knowledge Economy, Korea, under the Information Technology Research Center support program supervised by the National IT Industry Promotion Agency (NIPA) under Grant NIPA-2010-(C1090-1011-0005) . The review of this paper was coordinated by Prof. R. C. Qiu.
All Science Journal Classification (ASJC) codes
- Automotive Engineering
- Aerospace Engineering
- Electrical and Electronic Engineering
- Applied Mathematics