摘要
向拥有较宽连续频谱的高频频段扩展带宽成为未来高铁无线通信系统提升容量的有力手段,不过,需要采用大规模天线波束赋形技术克服高频频段路径损耗严重的缺陷。在高铁双车载台方案中,可以通过大规模天线阵列形成双波束传输提高系统容量。在对其传输性能进行分析后发现,双波束传输优化配置与列车的位置有关。基于此,论文提出自适应波束分合传输方案,当列车距离基站较远时,为了避免波束间的严重干扰,双波束合成为一个波束来覆盖两个接收端,实现接收分集,提高接收信号质量;当列车距离基站较近时,分裂成双波束,实现空间复用,提高系统容量及传输可靠性。数值仿真结果表明,所提方案可以适应列车运行位置,提升传输性能。
For future railway wireless communication networks, it is an effective way to adopt higher frequency spectra with broader bandwidth to enhance the transmission capacity. Nevertheless, massive beamforming techniques are needed to overcome the severe path loss of higher frequency spectra. For railway systems with dual on-vehicle receivers, dual-beam transmissions can be implemented to improve the capacity. The analysis results show that the optimization of dual-beam transmissions depends on the train position. Based on the above, an adaptive beam splitting or integrating communication scheme is proposed. When the train is far away from the base station, to avoid the inter-beam interference, an integrated beam with wider beamwidth is used to cover the two receivers to realize diversity receiving. As the train is approaching the center of the base station, two beams are generated to realize space multiplexing, to improve the transmission capacity and reliability. Numerical simulation results demonstrate that the proposed scheme can adapt to train positions and improve the transmission performance.
出处
《电子与信息学报》
EI
CSCD
北大核心
2016年第1期146-152,共7页
Journal of Electronics & Information Technology
基金
国家973计划(2012CB316100)
国家自然科学基金(61471303)
中国铁路总公司科技研究开发计划(Z2014-X002)~~
关键词
高铁无线通信
波束赋形
波束分合
复用
分集
Railway wireless communication
Beamforming
Beam-splitting or integrating
Multiplexing
Diversity
