|United States Of America||Issued Patent||9,621,221||04/11/2017||2013-666|
A key challenge in utilizing full-duplex radio is self-interference cancellation (SIC). One component of SIC, transmission noise, severely limits full-duplex as no digital or hybrid methods has any built in mechanism to deal with transmission noise.
University of California researchers have developed a closed-loop, digitally controlled and analog interfaced method for cancelling interferences from a set of RF transmit chains to a set of RF receive chains. This novel analog-digital method is no longer limited by transmission noise. The invention can be used to recover a weak signal in the presence of a stronger signal. This method can be used in parallel or in serial for better combined effect. The final structure of the system is such that all interference and major noise sources have a zero or minimum net contribution to the received digital signals.