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    基于部分信道信息反馈的多用户MIMO传输机制研究

    Study of Multiuser MIMO Transmission Scheme with Limited Feedback

    • 摘要: 在宽带无线通信系统中,多天线技术的实现依赖于多用户MIMO传输机制及信道信息反馈的有效解决.提出一种发送端进行干扰消除的TIE算法及相应的用户选择算法和功率分配算法,并提出一种基于向量量化的部分信道信息反馈机制,可以在多用户环境中提高系统性能并能有效降低信道信息反馈开销.分析了采用部分信道反馈机制的TIE算法的性能,论证了其性能特征.实验结果表明,与其他算法相比TIE算法可以有效地提高系统数据速率,而部分信道反馈机制可以在保持系统数据速率的前提下极大地降低信道反馈信令的开销.

       

      Abstract: In broadband wireless communication systems, the practicability of MIMO techniques relies on the solutions of multiuser MIMO transmission schemes and feedback schemes of channel state information (CSI). Most researches on limited feedback focus on point-to-point transmission systems. In multiuser MIMO systems, the reduction of feedback signaling overhead is more important since the base station relies on the CSI of all receiving terminals. In this paper, a transmitter interference elimination (TIE) scheme based on the reverse matrix of signature matrix is proposed to improve the system performance. A user selection algorithm is proposed to choose the transmitting users that generate the minimum interference to each other. A power allocation algorithm based on the water-filling algorithm is also proposed to maximize the system throughput. In addition, a limited feedback scheme based on vector quantization is proposed to reduce the feedback signaling overhead. Finally, the performance characteristics of TIE under limited feedback is studied and proved. It is shown that the multiuser interference generated by quantization error is linearly proportional to the transmitting power. It is also shown both in analysis and in simulation that the performance of multiuser MIMO systems under limited feedback are upper bounded because of the multiuser interference generated by feedback error. Numerical results show that the proposed scheme achieves significant throughput improvement while reducing the feedback overhead.

       

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