摘要
Large-scale array aided beamforming improves the spectral efficiency(SE) as a benefit of high angular resolution.When dual-beam downlink beamforming is applied to the train moving towards cell edge,the inter-beam ambiguity(IBA) increases as the directional difference between beams becomes smaller.An adaptive antenna activation based beamforming scheme was proposed to mitigate IBA.In the district near the base station(BS),all antenna elements(AEs) were activated to generate two beams.As the distance from the train to the BS increased,only the minimum number of AEs satisfying the resolution criterion would be activated.At the cell edge,one beam was switched off due to intolerable IBA.The proposed scheme can achieve SE gain to the non-adaptive scheme and show more robustness against the direction-of-arrival(DOA) estimation error.
Large-scale array aided beamform- ing improves the spectral efficiency （SE） as a benefit of high angular resolution. When dual-beam downlink beamforming is applied to the train moving towards cell edge, the inter-beam ambiguity （IBA） increases as the directional difference between beams becomes smaller. An adaptive antenna activation based beamforming scheme was proposed to miti- gate IBA. In the district near the base station （BS）, all antenna elements （AEs） were activated to generate two beams. As the distance from the train to the BS increased, only the minimum number of AEs satisfying the resolution criterion would be activated. At the cell edge, one beam was switched off due to intolerable IBA. The proposed scheme can achieve SE gain to the non-adaptive scheme and show more robustness against the direction-of-arrival （DOA） estimation error.
基金
supported partially by the 973 Program under the Grant 2012CB316100
关键词
自适应天线
波束形成
激活
高速铁路
通信系统
MIMO
角分辨率
高频谱效率
wireless communications
adap- tive antenna activation
large-scale antenna array
downlink beamforming
high speed railway
