Research And Simulation On Western IFF System’s Reconnaissance Techniques

Western IFF(IFF, Identification of Friend and Foe) system plays an important role in modern information war. Only if the non-cooperative reconnaissance party receives accurate signal between the two sides, and goes through a series of treatment and judgment, it is possible to achieve strategic superiority on the battlefield.The paper-based on Mode 5 IFF system’s standard signal process, includes mainly the following research work and obtain the appropriate outcome:1) The paper found that simulation with bandpass filter ignoring the impact of Gaussian white noise is unreasonable. This paper proposes improvements, and then give re-derivation formula and simulation. For Mode 5 interrogation signal, level 1 response signal and level 2 response signal, after simulation of energy detection probability, the conclusion is that the level 2 response signal energy detection probability is the best.2) In this paper, the boundary localization algorithm based on mode 5 standard signal is proposed. We simulate the algorithm from a single header pulse boundary to mode 5 interrogation signal, level 1 and level 2 response signal. The simulation results show that: when SNR is 0d B, single header pulse boundary localization successful probability is 100%, while the overall signal’s probability of successful boundary localization is more than 86%. The border localization algorithm performance well.3) Parameter estimation mainly includes the frequency estimation and symbol rate estimation. The main method of the frequency estimation are frequency centered algorithm and KAY algorithm. The simulation results show that: the effect of mode 5 interrogation signal and the level 2 response signal are better by using frequency centered algorithm compared with KAY algorithm. Symbol rate estimation have the same effect for the three signal.4) Pattern recognition means processing the detected signal separetly, and then extracts information such as the instantaneous amplitude of each channel’s signal, and compares the instantaneous phase, instantaneous frequency, spectrum symmetry parameter, the parameters of each channel with the threshold value. All in compliance with the requirements can be the detected MSK signal. In this paper, several parameters are used in pattern recognition and simulation studies is carried out that M5 interrogation signal’s energy detection probability performance is the worst, however it’s pattern recognition probability the best.5) Finally, this paper develops the "Western IFF system reconnaissance simulation software." The software includes a target system entity(including interrogator and transponder entity), the target entity parameter detection and surveillance equipment, based on Java Swing development, embedded World Wind three-dimensional geographic display system, the background signal processing algorithm by Matlab implementation. By creating a scene, software can get both collaborative inquiry response workflow analysis of each part, but also the non-cooperative reconnaissance equipment’s performance.In summary, this paper introduces the IFF Mode 5 system signal flow, analyses and studies the energy detection, boundary localization, parameter estimation and pattern recognition from the perspective of reconnaissance plane, and gives the corresponding simulation results and analysis. Finally, this paper design a simulation software to verify the algorithms.