Analysis and Experimental Verification of Digital Self-Interference Cancelation for Co-time Co-frequency Full-Duplex LTE

Abstract

In the communication mechanism of co-time co-frequency full-duplex (CCFD), digital self-interference cancellation (SIC) is used for suppressing residual self-interference (SI) after antenna and radio frequency (RF) SICs, as well as low-power multipath SI. In this study, the CCFD LTE verification experiment is presented, which adopts digital SIC with the SI signal reconstructed in frequency domain. For the multipath Rayleigh SI channel, the expression of digital SIC capability is derived and the relationship among the channel estimation error, the received SI power, and digital SIC capability is analyzed. Experimental results show that the digital SIC ability is 31.2 dB for a 20 MHz 16QAM modulated LTE SI signal with frequency centered at 2.6 GHz and the interference-to-noise ratio of 40 dB.