Biphase coding signal features high security and strong anti-intercept ability in the radar system. because it can be produced and processed easily with digital method, moreover, its waveform characters randomicity and the code can be quickly changed. But the biphase coding signal doesn't fit for detecting multiple targets and fast moving targets due to its high peak-sidelobe level(PSL) and its high sensitivity to Doppler frequency when it is processed with matched filter. To solve those problems, the technology of searching mismatched filter is used to find a kind of optimizing code to replace former biphase code,. Furthermore, Based on mismatched filter, compensatory sidelobe suppressing filter(SSF) is put forward to enlarge the Doppler tolerance, viz. design the SSF make the center lies in one third or half of the required tolerance. the simulation results for the radar system, show clearly that the rate-main-subsidiary(RMS) is improved greatly by fusing above two methods. The clutter is suppressed and the detecting capability of radar is improved to a great extent.
