基于盲极化斜投影的全双工用户间干扰消除技术

Blind Polarization Oblique Projection-based Inter-User Interference Cancellation in Full Duplex Multiuser System

随着无线技术的快速发展,无线频谱资源日益短缺。提高频谱利用率,在有限的频带范围内提升信息传输速率,成为国内外研究的热点问题。全双工通信系统由于其高效的频谱利用率备受关注。在多用户全双工系统中,基站进行全双工通信,能同时采用同一频段与上下行的用户进行通信。下行用户处会受到来自上行用户发射信号的用户间同频干扰,严重影响整个系统的性能。因此,提出了一种基于盲极化斜投影的方法来消除用户间干扰。相比于现有的方法,该方法不需要额外的频带资源去解码干扰信号,仅仅需要接收信号的极化状态信息和自协方差矩阵信息构建斜投影算子,能够将用户间干扰投影到算子的零空间。仿真结果表明,所提方法能够有效消除全双工系统用户间干扰,并显著提高系统的数据速率。

With the rapid development of wireless technology, the wireless spectrum resources become increasingly scare. How to improve the spectrum utilization and raise the information transmission rate in the limited frequency range is now a hot topic both at home and abroad. Full- duplex communication system, for its efficient spectrum utilization, attracts much attention from people.In a multiuser full- duplex system, the basestation performs full-duplex communication and can simultaneously communicate with the up-link or down-link user on the same frequency band. The downlink user would be subject to the same frequency interference between users from the uplink users, this would seriously affect the performance of the whole system. Therefore, the method based on blind polarization oblique projection is proposed, so as to eliminate inter-user interference. Compared with the existing methods, this method requires no additional frequency band resources for decoding the interference signals, and only the receiving of polarization information and self-covariance matrix information, thus constructing oblique projection operator and mapping the inter-user interference into the null space of operators. The simulation result indicates that the proposed method could effectively eliminate inter-user interference in the full -duplex system and improve the data rate of the system significantly.