机会波束中的发射波束自适应截断

Adaptive Truncating of Transmitting Beams in Opportunistic beamforming

为了快速有效地选择最优发射波束和降低多用户多输入单输出系统中反馈用户的个数，提出了在系统中自适应截断机会波束的技术。该技术以最大化吞吐量为原则在用户端预先设定信干噪比截断门限，只有接收信干噪比大于门限值时才向基站反馈；基站截断没有反馈信息的发射波束，以达到优化随机发射波束、降低波束间干扰、最大化系统容量的目的；通过预先设置的截断门限可以显著减少用户反馈，提高资源利用率。在瑞利衰落信道中分析与仿真了自适应截断机会波束的容量性能和反馈量，得到不同环境中的最优截断门限，仿真结果表明最优门限下的自适应截断技术降低了系统反馈，提高了机会波束系统的吞吐量。

For the purposes of selecting beams and reducing system feedbacks, the technique of adaptive truncating of opportunistic beamforming in multiuser multiple-input single-output （MISO） systems is proposed. It sets the truncating threshold based on maximizing the system throughput. W3aen the received signal to interference noise ratio （SINR） is larger than the pre-established threshold, the user feeds it back. The transmitting beam with no feedback will be truncated to reduce the interference, optimize the transmitting beams, and enlarge the throughput. Through the pre-established thresholds, feedbacks will be decreased significantly and the resource utilization efficiency will be improved. Analysis and simulations in the Rayleigh fading channel are given, and the results demonstrate that through setting the threshold reasonably, the adaptive truncating opportunistic beamforming system can reduce the feedbacks and increase the throughput.