Digital Self-Interference Cancellation for Full-Duplex UAV Communication System over Time-Varying Channels

Full-duplex unmanned aerial vehicle (UAV) communication systems are characterized by mobility, so the self-interference (SI) channel characteristics change over time constantly. In full-duplex UAV systems, difficulty is to eliminate SI in time-varying channels. this paper, we propose a pilot-aid digital cancellation (SIC) method. First, pilot inserted into data sequence uniformly, and modeled as linear non-causal function. Then, estimated discrete prolate spheroidal basis expansion model (BEM). The error of block edge estimation reduced cross-block interpolation. result convolved with transmitted obtain reconstructed SI, which subtracted from received signal achieve SIC. simulation results show that SIC performance proposed method outperforms dichotomous coordinate descent recursive least square (DCD-RLS) normalized mean (NLMS) algorithms. When interference noise ratio (INR) 25 dB, index (NMSE) 5.5 dB 4 compared DCD-RLS NLMS algorithms, can floor, advantage becomes more obvious INR increases.