Broadband cancellation method in an adaptive co-site interference cancellation system

With the boom of communication systems on independent platforms (such as, airplanes and vessels), co-site interference has become prominent. Currently, extensive research has been conducted on the development of an adaptive co-site interference cancellation system (ACICS); however, the related interference cancellation bandwidth characteristics have not been adequately investigated, thereby critically restricting the further optimisation of the ACICS design. In this study, the bandwidth signal calculation formula of the ACICS interference cancellation ratio is derived, and the quantitative relationships among the interference cancellation bandwidth, interference cancellation ratio, system gain, and delay-matching degree are analysed exhaustively. The results reveal that the higher the required interference cancellation ratio, the smaller is the interference cancellation bandwidth; the interference cancellation bandwidth can be enhanced to a limited degree by increasing the system gain. Furthermore, the interference cancellation bandwidth and the delay-matching distance follow an approximately inverse relation, and the interference cancellation bandwidth can be improved by delay matching. The nearest matching method can be employed for broadband interference. Finally, the conducted simulations and experiments validate the correctness and effectiveness of the theoretical analysis.