Balanced RF-circuit based self-interference cancellation for full duplex communications
Balanced RF-circuit based self-interference cancellation for full duplex communications
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DOI：
10.1016/j.adhoc.2014.09.001
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发表时间：
2015
期刊：
影响因子：
4.8
通讯作者：
Aimin Tang;Xudong Wang
中科院分区：
文献类型：
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作者：
Aimin Tang;Xudong Wang
模拟域中的自干扰消除对于实现全双工无线通信至关重要。然而，模拟自干扰消除的能力没有被充分探索。为此，本文提出了一种新的模拟自干扰抵消方法。更具体地，平衡RF前端电路被设计为允许信号通过对称路径传播，使得：（1）可以消除采用不同路径到达接收器的发射信号;（2）在接收器处简单地将来自不同路径的接收信号相加。结果，自干扰被优雅地消除，而不影响发送和接收的正常操作。此外，这种新方法包括几个不同的特点。首先，它可以实现高模拟自干扰消除。实验结果表明，该方法在5 MHz带宽上的自干扰消除能力大于65 dB，在100 MHz带宽上的自干扰消除能力大于52 dB，且具有平坦的频率响应。其次，新方法可以很容易地与现有的模拟自干扰消除方案集成，以提供更高的自干扰消除。第三，它可以以可扩展的方式容易地扩展到MIMO通信。实验表明，我们提出的天线抵消方案是足以实现模拟自干扰消除MIMO通信的目标。
Self-interference cancellation in the analog domain is critical to achieve full duplex wireless communications. However, the capability of analog self-interference cancellation is not fully explored. To this end, a new approach of analog self-interference cancellation is developed in this paper. More specifically, a balanced RF frond-end circuit is designed to allow a signal to propagate through symmetrical paths such that: (1) transmit signals taking different paths to arrive at the receiver can be cancelled; (2) receive signals from different paths are simply added at the receiver. As a result, self-interference is gracefully cancelled without impacting the normal operation of transmission and reception. Furthermore, this new approach includes several distinct features. First, it can achieve high analog self-interference cancellation. Implementation and experiments are conducted to validate the new approach, and experimental results show that it can achieve more than 65 dB of self-interference cancellation over 5 MHz bandwidth and 52 dB cancellation over 100 MHz bandwidth with a flat frequency response. Second, the new approach can be easily integrated with existing analog self-interference cancellation schemes to deliver much higher self-interference cancellation. Third, it can be easily extended to MIMO communications in a scalable way. Experiments show that our proposed antenna cancellation schemes are sufficient to achieve the goal of analog self-interference cancellation for MIMO communications.