Freedom of Frequency: How the Quest for In-Band Full-Duplex Led to a Breakthrough in Filter Design

Wireless self-interference cancellation (SIC) was developed at Stanford University [1], [2] (and spun out as Kumu Networks) to double the spectral efficiency of radio links. SIC enables radios to transmit and receive on the same channel at the same time by canceling out the roar of the local transmitter to hear the whisper of the distant signal.