A full duplex transceiver with reduced hardware complexity

For future wireless communication systems, full duplex is seen as a possible solution to the ever present spectrum shortage. The key aspect to enable In-Band Full Duplex (IBFD) is sufficient cancellation of the unavoidable Self-Interference (SI). In this work we evaluate the performance of a low complexity IBFD transceiver, including the required analog and digital interference cancellation techniques. The Radio Frequency Self- Interference Canceler (RFSIC) is based on the isolation of a circulator in combination with a vector modulator regenerating the interference signal, to destructively combine it with the received signal. On the digital side, a Digital Self-Interference Cancellation (DSIC) algorithm based on non-linear adaptive filtering is used. With the simplified analog front-end of a Software Defined Radio (SDR) platform, SI cancellation of 90 dB is achieved with the presence of a received signal.