Passive Self-Interference Suppression for Full-Duplex Infrastructure Nodes
Passive Self-Interference Suppression for Full-Duplex Infrastructure Nodes
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DOI：
10.1109/twc.2013.010214.130226
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发表时间：
2014-02-01
影响因子：
10.4
通讯作者：
Sabharwal, Ashutosh
中科院分区：
文献类型：
--
作者：
Everett, Evan;Sahai, Achaleshwar;Sabharwal, Ashutosh
最近的研究结果已经证明了全双工无线通信在短距离链路上的可行性。尽管先前的工作重点是主动消除自干扰信号，但总体自干扰抑制的大部分往往是由于被动抑制，即发射和接收天线的隔离。我们提出了一项基于测量的被动自干扰抑制三种关键机制的能力和局限性的研究：定向隔离、吸收屏蔽和交叉极化。研究表明，在某些环境下可以实现70 dB以上的被动抑制，但也建立了两个关于被动抑制局限性的结果：(1)环境反射限制了被动抑制的可实现量；(2)被动抑制一般增加了剩余自干扰信号的频率选择性。这些结果提出了两个设计启示：(1)全双工基础设施节点的部署应尽量减少近天线反射器，(2)与被动抑制相连接的主动抵消应采用高阶滤波器或每个子载波抵消。
Recent research results have demonstrated the feasibility of full-duplex wireless communication for short-range links. Although the focus of the previous works has been active cancellation of the self-interference signal, a majority of the overall self-interference suppression is often due to passive suppression, i.e., isolation of the transmit and receive antennas. We present a measurement-based study of the capabilities and limitations of three key mechanisms for passive self-interference suppression: directional isolation, absorptive shielding, and cross-polarization. The study demonstrates that more than 70 dB of passive suppression can be achieved in certain environments, but also establishes two results on the limitations of passive suppression: (1) environmental reflections limit the amount of passive suppression that can be achieved, and (2) passive suppression, in general, increases the frequency selectivity of the residual self-interference signal. These results suggest two design implications: (1) deployments of full-duplex infrastructure nodes should minimize near-antenna reflectors, and (2) active cancellation in concatenation with passive suppression should employ higher-order filters or per-subcarrier cancellation.