US Patent 9985772 Digital simultaneous transmit and receive communication system

In a simultaneous transmit and receive (STAR) communication system, an RF signal splitter couples an antenna to an RF transmitter and to an RF receiver, without using a circulator. An adaptive cancellation RF waveform generator generates an adaptive cancellation RF signal to cancel cross-talk from the RF transmitter to the RF receiver. Training signals are used to characterize signal paths within the STAR system and calculate filter coefficients for generating the adaptive cancellation signal.