6th International ICST Conference on Communications and Networking in China

Research Article

Multiple Doppler Shifts Compensation and ICI Elimination by Beamforming in High-Mobility OFDM Systems

  • @INPROCEEDINGS{10.1109/ChinaCom.2011.6158142,
        author={Ying Zhang and Qinye Yin and Pengcheng Mu and Lin Bai},
        title={Multiple Doppler Shifts Compensation and ICI Elimination by Beamforming in High-Mobility OFDM Systems},
        proceedings={6th International ICST Conference on Communications and Networking in China},
        publisher={IEEE},
        proceedings_a={CHINACOM},
        year={2012},
        month={3},
        keywords={ofdm doppler spreading antenna array beamforming intercarrier interference},
        doi={10.1109/ChinaCom.2011.6158142}
    }
    
  • Ying Zhang
    Qinye Yin
    Pengcheng Mu
    Lin Bai
    Year: 2012
    Multiple Doppler Shifts Compensation and ICI Elimination by Beamforming in High-Mobility OFDM Systems
    CHINACOM
    IEEE
    DOI: 10.1109/ChinaCom.2011.6158142
Ying Zhang1,*, Qinye Yin1, Pengcheng Mu1, Lin Bai1
  • 1: Xi'an Jiaotong University
*Contact email: daisy.zhangying@gmail.com

Abstract

Although OFDM is an effective way to mitigate the multipath spread of the wireless channels by a simple equalization, it is very sensitive to Doppler effect. Doppler spreading due to the mobility of communication terminals destroys the orthogonality among the subcarriers, and results in intercarrier interference, which degrades the system performance. In this paper, we employ array beamforming and interference suppression to compensate multiple Doppler shifts in high-speed OFDM systems. The proposed method uses uniform circular array to separate different paths with unique Doppler shift, and then correct Doppler offsets in different paths respectively. This scheme not only eases channel estimation and equalization but also utilizes the multipath characteristics of wireless channel and provides Doppler diversity gains. Simulation results show that when sufficient elements were used, the proposed scheme can effectively combat the BER error floor in high-mobility scenario and have great performance enhancement over traditional methods.