Self-interference Cancellation in In-band Full-duplex Communication Systems Using Special Pair of Complementary Sequences

This paper presents a digital domain self-interference (SI) cancellation algorithm employing complementary sequence pair based LS technique for in-band full-duplex (FD) orthogonal-frequency-division multiplexing systems over Rayleigh frequency selective fading scenario. Here SI channel estimation is performed under two scenarios. To obtain an efficient and reliable SI channel estimate, the intended signal transmitter is kept off in the first scenario, whereas the intended signal is considered as noise in the second scenario. For the estimation of the SI channel coefficients, special pairs of complementary sequences are constructed that reduces the complexity of time domain channel estimation. Further, SI cancellation is performed in digital domain to make practical FD system feasible. The simulation performances of the proposed algorithm outperforms the conventional techniques that proves its feasibility.