US Patent 9806790 Systems/methods of spectrally efficient communications

First and second receivers are used to receive respective first and second signals, to process said first and second signals and provide respective first and second measures thereof to respective first and second transmitters. The first and second transmitters are configured to launch the first and second measures, respectively, each comprising a desired component that has originated at a desired source, and an interference component that has originated at an interfering source. The first and/or second transmitters are configured to process and launch the respective first and second measures, properly conditioned, so that upon interception thereof by a receiving element the interference components thereof add destructively and substantially cancel (or at least partially cancel) each other, whereas the desired components avoid substantial cancellation owing to a phase relationship therebetween that differs relative to a phase relationship between the interference components.