Reducing FDD MMU Form Factor with Active Cancellation

In this paper, a multi-channel self-interference cancellation (SIC) technique is proposed to reduce the size of AWS/PCS dual-band 5G FDD massive MIMO base station. Combining two bands with small frequency offset such as PCS and AWS bands in a base station requires modification of frequency duplex cavity filters to provide a wide passband with extremely narrow gap between the passband and the stop band. Such duplexer is hard to realize. We propose a novel multi-channel SIC to allow the dual-band operation with the same form factor as the single-band base station. A proof of concept (PoC) prototype is developed to demonstrate the feasibility of multi-channel SIC to this problem.