Performance analysis of co-site interference suppression with imperfect time synchronization in wideband reconnaissance receivers

The onboard wideband reconnaissance receiver is faced with the problem of co-site interference of high-power radio transmitting signals in the same vehicle. One effective solution to this issue is interference reconstruction and cancellation. However, due to engineering errors, interference reconstruction signals and received signals cannot achieve perfect time synchronization, leading to a decline in the effectiveness of co-site interference cancellation. This paper establishes a co-site interference cancellation system model for the Nyquist folded receiver, and then presents a closed expression for the residual interference power and co-site interference cancellation ratio by considering the influence of non-ideal factors, such as the multipath effect of the interference propagation channel and time synchronization error. Additionally, this paper theoretically analyzes the influence of the time synchronization error of the co-site interference reconstruction signal on the performance of co-site interference suppression. The simulation results under different conditions validate the correctness of the theoretical analysis.