Good document, also, http://www.mit.edu/~viveck/code/Research_files/fbdof-1.pdf http://www.mit.edu/~viveck/code/Research_files/fbdof-1.pdf covers broader topics

Good document, also, http://www.mit.edu/~viveck/code/Research_files/fbdof-1.pdf http://www.mit.edu/~viveck/code/Research_files/fbdof-1.pdf covers broader topics including FulL Dux. Simple laymen's explanation, the transmitter wave form is fed back into the receiver but inverted so it cancels out the transmitters signal. You can think of this like noise cancelling headphones in reverse. With noise cancelling headphones you sample outside noise and invert it to cancel that. Here you sample your own signal and invert it and add it to the received signal and the inverted signal cancels out the transmitted signal. This technology has been around a while but the DSP technology is just now really getting good enough for it to be practical.