Analysis of RF Feedback Chain Isolation in Wireless Co-Time Co-Frequency Full Duplex

By employing a radio frequency (RF) feedback chain, the self-interference can be canceled efficiently in co-time co-frequency full duplex (CCFD). However, the evitable signal crosstalk which is caused by the imperfect RF feedback chain isolation usually damages the self-interference cancelation (SIC) performance. To deal with this problem, firstly, we analyze the impact of RF feedback chain isolation on SIC performance. Then a digital pre-processing scheme with RF feedback chain is proposed in the multiple-antenna CCFD architecture. Using both analytical and experimental methods, we find that the proposed scheme achieves a better performance on SIC.