 with a dramatically affected SNR. To achieve the best performance of a full-duplex system, the self-interference signal must be suppressed to reach the receiver's noise floor. The self-interference may be originated from the linear components and the RF carrier itself, which is attenuated and reflected from the environment. The received distortion can be modeled as a linear combination of differ- ent delayed copies of the original carrier. It can be further generated by nonlinear compo- nents because the imperfect radio circuits typically create third and fifth intermodulation products of the transmit signal. These higher order intermodulation terms have significant frequency content at frequencies close to the transmitted frequencies, which directly corre- spond to other harmonics. The self-interference can also be caused by the transmitter noise, which appears as an increase of about 50 dB over receiver noise floor. Due to random nature of this component, it can only be canceled by subtracting the appropriately weighted transmitter signal sampled in the analog domain from the received signal. For narrowband systems, the self-interference channel can be modeled as gain and delay functions, whereas wideband systems require a more complex model, because the reflected-path self-interfer- ence channel is often frequency-selective as a result of multipath propagation. In general, one can model the process in the digital domain that is valid for both the nar- rowband and wideband scenarios as r(n) = ra(n) + wr(n) + rdsi(n) + rssi(n) where r(n) is total received complex-valued baseband samples, ra(n) is the desired signal from the remote node, rdsi(n) denotes the complex-valued samples caused by the direct self-interference component signal between the transmit and receive antennas in case of two antennas, or leaked signal in the circulator in case of one antenna, rssi(n) represents the complex-valued samples caused by scattered self-interference components, and wr(n) denotes additive white Gaussian noise. A circulato