## 1 Introduction  
Radio fuze is the information equipment at the end of the weapon action process and is the core of the munition damage control. Frequency modulation continuous wave (FMCW) fuze uses the frequency difference between the transmitted signal and the echo signal to determine the distance of the target. The distance measurement does not depend on the amplitude of the echo signal, and compared with the continuous wave Doppler, fuze has the advantages of small scattering of the bursting point, high accuracy of ranging, and high anti-jamming ability, etc. FMCW fuze is widely used in modern weapons due to its accurate ranging and anti-jamming ability [1, 2, 3, 4]. However, with the development of electronic countermeasures technology, the electromagnetic battlefield environment is becoming more and more complex, and radio fuze is facing serious threats, especially frequency sweeping jamming [5, 6]. Therefore, improving the FMCW fuze have the ability of anti-frequency sweeping jamming has a direct impact on its maximum effectiveness in the battlefield environment. A great deal of research was carried out on the anti-jamming of radio fuze. In terms of the research object, anti-jamming research of radio fuze is divided into two main parts, one based on the transmit signal waveform design [7, 8, 9, 10], and the other based on the fuze output beat signal processing [11, 12, 13, 14]. In the areas of transmit signal waveform design, [PERSON] et al. [7] proposed a novel fractional-Fourier-transform (FRFT)-based LFMCW to achieve distance measurement for a collision avoidance detector. The proposed detector information is acquired from the intermediate frequency signal (IFS), which is obtained by mixing the echo signal with the reference carrier signal. The new IFS-based structure transceiver reduces the computation complexity of FRT by taking advantage of the knowledge of the frequency modulation slope. [PERSON] et al. [8] proposed an anti-jamming method based on harmonic coefficient amplitude average, in order to improve the anti-sweeping frequency jamming performance of the chaotic codes phase modulation and linear frequency modulation (CCPM-LFM) hybrid modulation radio fuze. This method uses a fast Fourier transform algorithm to extract the harmonic envelope and averages the amplitude of the harmonic coefficients obtained from multiple FFT, making full use of the random and statistical properties of chaotic codes to suppress jamming. [PERSON] et al. [9] proposed an anti-DRFM-jamming method based on the averaging of the range side lobes, and the binary-phase-coded chirp waveform, which is aperiodic in design. The chaotic codes vary with the linear frequency modulation period to make the binary-phase-coded chirp waveforms aperiodic, and the range side lobes are used to suppress the influence of the DRFM. [PERSON] [10] developed radar signaling to combat the impact of the repeat jammers on the radar system. Robustness against jammers is achieved by employing the concept of pulse diversity, where the radar, at each pulse repetition interval, emits either a modified version of the previous waveform or a new waveform following a specific orthogonal structure. These methods improve the immunity of the radio fuze to interference, however, improvements to the signal transmission module are required, making the fuze more complex. In the areas of output beat signal processing, [PERSON] et al. [11] proposed a method for adaptive identification of fuze targets and jamming signals based on the minimal risk Bayesian criterion, by analyzing the time and frequency domain characteristics of the output signal of the fuze filter, the time- and frequency-domain feature spaces of the target signal and the jamming signals are constructed; finally, a risk minimum Bayesian classifier model is built to classify the feature space. [PERSON] et al.