erimentally proved to be sufficiently robust; however, the suppression drastically decreases in case of wideband signals. The antenna directionality isolates the receiving antenna from the interfering signals of the transmitting antenna; TX data Baseband processing module Path loss Analog SIC control Digital SIC Analog SIC Full scale Baseband processing RX data module SSINR Dynamic range Digital Digital SIC Analog SIC Passive suppression (20-35 dB) using separate (20-45 dB) before LNA to (20-30 dB) suppressing linear and nonlinear SIC avoid ADC saturation and linear and nonlinear SIC limiting precission Quantized noise floor Figure 3.39 Example Wi-Fi or LTE signals, which are typically transmitted at an average power of 23 dBm (200 mW). The thermal noise level at 20 MHz bandwidth is about - 101 dBm 174 dBm/ Hz + 73 dB) [40,41]. New Radio Access Physical Layer Aspects (Part 1) 377 however, such an approach would not work for point-to-point full-duplex scenarios. Electromagnetic shielding can enhance the isolation between transmit and receive anten- nas. Nevertheless, one disadvantage is that the shielding affects the far-field antenna pat- terns because it prevents the antenna from transmitting to/receiving from the shielding direction; thus it is only relevant to the case of directional antennas. Self-interference can be mitigated using orthogonal polarization between the transmit/receive antennas, achiev- ing about 10-20 dB isolation in an anechoic chamber and 6-9 dB in a reflective room at 2.4 GHz. The dual-polarized antenna can suppress self-interference by transmitting and receiving through orthogonal polarization. The isolation characteristic of a dual-polarized antenna can be expressed by its XPD factor. In transmit mode, XPD is the proportion of the signal that is transmitted in the orthogonal polarization to the desired direction. In receive mode, it is the antenna's ability to maintain the incident signal's polarization purity. For example, if a perfectly vertically polarized signal (containing no horizo