A Novel Application of RLS Algorithm Based on Fractional Fourier Domain in the Presence of Non-cooperative Radiation Source

High frequency hybrid sky-surface wave radar(H SSWR) is widely used due to its wide propagation distance and rich state information of propagation space which covers not only the ocean surface but also the ionosphere. However, for the receiving subsystem, the complex electromagnetic space in which it operates can cause significant interference to the echo signal, especially for non-cooperative radiation sources with similar operating frequency bands. In the above situation, this article found that groups of range-domain periodic interference (GRPI) occur in the HSSWR echoes. This paper proposes a FRFT based recursive least squares (RLS) suppression algorithm. Simulations have demonstrated its effectiveness.