关键词: 高速铁路, 多波束, 机会波束赋形

Abstract: In the high-speed railway communication, the position information of train is predictable. However, the number of relaying antennas on the roof is limited, the feedback delay is large, Doppler effect is often serious, handover is frequent, and so on. Therefore, the traditional beamforming is not suitable for high speed railway communications. By taking the advantage of the predictability of the location information of the train, this paper proposes a kind of location information auxiliary multi-beam opportunistic beamforming, which can improve the accuracy of the weighted vector of the beam for the opportunistic beamforming algorithm. The scheme also supports multiple beam parallel transmission, so as to realize better multiuser diversity gain with multi-beam selection. Because opportunistic beamforming needs only some parameters such as SNR in the receiver, the feedback overhead is also reduced. Thus, the scheme proposed in the paper is suitable for high speed railway communications.

Key words: high speed railway, multi-beam, opportunistic beamforming