Integrated Self-Interference Cancellation for Next-Generation Wireless Communication Systems

The ever-increasing demand for wireless applications is creating an unprecedented spectrum crunch. To alleviate the pressure on limited spectrum resources, new communication paradigms, such as full-duplex wireless, have emerged. Simultaneously transmitting and receiving at the same frequency, full-duplex radios promise a bonanza in RF spectrum efficiency. However, concurrent transmission and reception results in tremendous transmitter self-interference which must be cancelled to the receiver noise floor. In this talk, challenges associated with self-interference cancellation (SIC), especially using RFIC technology, will be unveiled. Next, I will briefly review several recent integrated SIC techniques that eliminate of the noise and distortion of the cancellation circuitry, enhance cancellation bandwidth, and achieve cancellation with nearly one part-per-billion accuracy. Integrated SIC will also play a pivotal role in future multi-band frequency-division-duplexing (FDD) systems. A tunable FDD wireless system with an evanescent-mode duplexer and an SIC receiver will be shown. Finally, I will conclude the talk with a discussion of the remaining problems in SIC for full-duplex and tunable/reconfigurable RF systems.