A Broadband Multistage Self-Interference Canceller for Full-Duplex MIMO Radios
A Broadband Multistage Self-Interference Canceller for Full-Duplex MIMO Radios
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DOI：
10.1109/tmtt.2021.3060792
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发表时间：
2021-04-01
影响因子：
4.3
通讯作者：
Madanayake, Arjuna
中科院分区：
文献类型：
--
作者：
Zhao, Haixiang;De Silva, Udara;Madanayake, Arjuna
全双工（FD）天线阵列是将无线系统的信道容量扩展到2的理想选择，这在拥挤的6 ghz以下频谱频段尤为重要。传统的基于环行器的FD解决方案不能扩展到天线阵列，因为天线元件之间存在显著的相互耦合。本文介绍了一种适用于FD阵列的两级自干扰消除（SIC）方法。第一阶段SIC使用基于复制天线（RA）的无源线性网络，因此可以放置在低噪声放大器（LNA）之前，而不会显著降低接收机噪声系数（NF）和线性度。基于ra的SIC还简化了第二阶段SIC的硬件要求，第二阶段SIC使用模拟抽头延迟线（ATDL）网络。所提出的两级SIC使用现成的组件实现，并使用强耦合对超宽带天线在1-3 ghz范围内进行了测试。网络分析仪测量显示，在整个频率范围内，使用RA网络的SIC为20-30 dB，使用单级ATDL SIC的SIC为20- 20 dB，瞬时带宽为0.53-0.65 GHz。在1、2和3 GHz的中心频率附近，联合发射(Tx)-接收隔离度分别为66.5、73.5和85.8 dB。隔离的数量被证明足以实现实用的FD无线链路在2 GHz与合理的Tx功率电平（0 dBm）。
Full-duplex (FD) antenna arrays are desirable for expanding the channel capacity of wireless systems up to 2, which is particularly important in the crowded sub-6-GHz spectral bands. Conventional FD solutions based on circulators do not scale to antenna arrays due to the presence of significant mutual coupling between antenna elements. This article describes a two-stage self-interference cancellation (SIC) method that is suitable for FD arrays. The first-stage SIC uses a replica-antenna (RA)-based network that is passive and linear and can thus be placed before the low-noise amplifier (LNA) without significantly degrading receiver noise figure (NF) and linearity. The RA-based SIC also simplifies the hardware requirements for the second-stage SIC, which uses an analog tapped delay line (ATDL) network. The proposed two-stage SIC was realized using off-the-shelf components and tested in the 1-3-GHz range using strongly coupled pairs of ultrawideband antennas. Network analyzer measurements show 20-30 dB of SIC using the RA network over the entire frequency range and >20 dB of SIC using a single-stage ATDL SIC over instantaneous bandwidths of 0.53-0.65 GHz. The combined transmit (Tx)-receive isolation is 66.5, 73.5, and 85.8 dB around the center frequencies of 1, 2, and 3 GHz, respectively. The amount of isolation is shown to be sufficient for realizing practical FD wireless links at 2 GHz with reasonable Tx power levels (0 dBm).