Frequency-Domain RF Self-Interference Cancellation for In-Band Full-Duplex Communications

Wireless backhaul has recently gained a significant amount of interest as a cost-effective solution in comparison with conventional backhaul technologies with dedicated microwave links or fiber optics. Self-interference cancellation (SIC) is an enabling technology that allows wireless backhaul to op...

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Bibliographic Details
Published inIEEE transactions on wireless communications Vol. 22; no. 4; p. 1
Main Authors Hong, Zhihong Hunter, Zhang, Liang, Li, Wei, Wu, Yiyan, Zhu, Zhiwen, Park, Sung-Ik, Ahn, Sungjun, Kwon, Sunhyoung, Hur, Namho, Iradier, Eneko, Montalban, Jon, Angueira, Pablo
Format Journal Article
LanguageEnglish
Published New York IEEE 01.04.2023
The Institute of Electrical and Electronics Engineers, Inc. (IEEE)
Subjects
adaptive filter
Adaptive filters
Algorithms
Backhaul networks
Fiber optics
Frequency domain analysis
In-band full-duplex
Interference
Interference cancellation
Low frequencies
Optimization
Radio frequency
self-interference cancellation
Training
wireless backhaul
Wireless communication
Wireless communications
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Summary:Wireless backhaul has recently gained a significant amount of interest as a cost-effective solution in comparison with conventional backhaul technologies with dedicated microwave links or fiber optics. Self-interference cancellation (SIC) is an enabling technology that allows wireless backhaul to operate in the more spectrum-efficient in-band full-duplex (IBFD) operation mode instead of the out-of-band mode. Compared to Wi-Fi IBFD transceivers, wireless in-band backhaul systems face some unique challenges, such as significantly higher transmission power and much larger propagation delay spread for the self-interference signal, especially in the low-frequency bands under 1 GHz, which often prevent accurate SIC performance. The SIC is often implemented with an interference-cancelling filter, where the filter weights are essentially the channel estimates of the self-interference signals. In this paper, a frequency-domain Radio Frequency (RF) SIC (RF-SIC) framework with a novel filter weight optimization algorithm is proposed to tackle the challenges of wireless in-band backhaul. The proposed RF-SIC does not require a dedicated training phase which needs to stop the transmission of the backhaul signal. Moreover, it has the capability of tracking the self-interference channel variation since the filter weights are updated in a block-by-block fashion.
ISSN:1536-1276
1558-2248
DOI:10.1109/TWC.2022.3211196