Research On Characteristics Of Interrupted Sampling Repeater Jamming And Anti-jamming Waveform Design

With the development of modern radar electronic warfare,the jamming efficiency and the response speed of jammer are significantly important.The traditional barrage jamming and deceptive jamming are difficult to achieve an effective jamming performance due to the low jamming efficiency,slow response and the need to receive the whole signal.The interrupted sampling repeater jamming(ISRJ)is proposed to break through the jamming bottleneck,which can form a series of realistic coherent false targets by low-rate sampling and forwarding the intercepted radar signal.The mode of ISRJ improves the response speed and the efficiency of jamming greatly.Because of the significant performance of ISRJ in deception and suppression,the corresponding countermeasure technology needs further developed.Up to now,although the countermeasure technology of ISRJ has several decades of development,and has achieved some accomplishments,from overall it seems the research is still in its infancy.The current researches mainly focus on the radar receiver by implementing the methods,such as: interference identification and signal processing,to realize the suppression of ISRJ.But the current methods are difficult to achieve an effective suppression performance due to the complicated algorithm and low suppression efficiency.Based on the above background,focusing on the characteristics of ISRJ,we propose a dynamic electronic counter countermeasure(ECCM)scheme based on jammer parameter estimation and transmitted signal design.The results of the research will provide theoretical support for ISRJ countermeasure technology.The main work and results are as follows:Chapter 1 illustrates the background and significance of this research subject,and introduces the present status of radar jamming technologies.The development of trend and existing problems of radar countermeasure techniques are especially analyzed.The present status of ISRJ and corresponding countermeasures are further summarized.The major research efforts of this dissertation are also explained.Chapter 2 introduces the principle of ISRJ firstly.Then the characteristics of ISRJ signal are mainly analyzed by adopting the theories of matched filter and ambiguity function.Secondly,three repeater modes are introduced,and the mathematic mode of ISRJ under different repeater ways are derived.Ultimately,the performances of ISRJ with different repeater modes under LFM radar are analyzed in simulation results.Chapter 3 studies the ISRJ performance of intra-pulse frequency-coded(IPFC)signal.The mathematic mode of IPFC signal is illustrated and the characteristics of IPFC signal in time domain,frequency domain and matched filtering result are analyzed.We focus on the efficiency of ISRJ under IPFC signal,and the influence of sub-pulse number on jamming effect is mainly analyzed.The simulation results illustrate the performance of ISRJ under IPFC signal and verify the influence of ISRJ performance and matched filtering performance under different sub-pulse number of IPFC signal.Chapter 4 proposed an ECCM scheme for countering ISRJ based on time-frequency(TF)analysis and waveform design.We first transmit the LFM signal to estimate the main parameters(i.e.interrupted sampling repeating interval,sampling duration and repeater times)by exploiting the discontinuous characteristics of ISRJ in TF domain,and then a parameters-adjusted intra-pulse frequency coded train is designed adaptively,whose ISRJ signal only generates a single false target behind the real target.Next,we propose two ISRJ suppression approaches based on the estimated parameters.Ultimately,the anti-jamming performances of two approaches under different scenes are analyzed,and the flow chart of proposed ECCM is illustrated.Simulation results validate the effective performance of the proposed scheme for countering ISRJ.Chapter 5 makes a summary of the studies and draw main contributions of the research.The perspectives of ISRJ countermeasure technology in multi-target,multi-jammer and other complicated battlefield environment are prospected and some open problems are also presented.