School of Mechatronical Engineering, Beijing Institute of Technology, Beijing 100089, China.
Sensors (Basel). 2023 Jan 3;23(1):554. doi: 10.3390/s23010554.
Parameter estimation is extremely important for a radar jammer. With binary phase shift keying (BPSK) signals widely applied in radar systems, estimating the parameters of BPSK signals has attracted increasing attention. However, the BPSK signal is difficult to be processed by traditional time frequency analysis methods due to its phase jumping and abrupt discontinuity features which makes it difficult to extract PN (PN) codes of the BPSK signal. To solve this problem, a two-step PN codes estimation method based on sparse recovery is introduced in this paper. The proposed method first pretreats the BPSK signal by estimating its center frequency and converting it to zero intermediate frequency (ZIF). The pretreatment transforms phase jumps of the BPSK signal into the level jumps of the ZIF signal. By nonconvex sparsity promoting regularization, the level jumps of the ZIF signal are extracted through an iterative algorithm. Its effectiveness is verified by numeric simulations and semiphysical tests. The corresponding results demonstrate that the proposed method is able to estimate PN codes from the BPSK signal in serious electromagnetic environments.
参数估计对于雷达干扰机至关重要。随着二进制相移键控（BPSK）信号在雷达系统中的广泛应用，对 BPSK 信号参数的估计引起了越来越多的关注。然而，由于 BPSK 信号的相位跳变和急剧不连续特性，传统的时频分析方法很难对其进行处理，这使得难以提取 BPSK 信号的 PN（伪噪声）码。为了解决这个问题，本文提出了一种基于稀疏恢复的两步 PN 码估计方法。该方法首先通过估计 BPSK 信号的中心频率并将其转换为零中频（ZIF）来预处理 BPSK 信号。预处理将 BPSK 信号的相位跳变转换为 ZIF 信号的电平跳变。通过非凸稀疏促进正则化，通过迭代算法提取 ZIF 信号的电平跳变。数值模拟和半物理测试验证了其有效性。相应的结果表明，该方法能够在严重的电磁环境中从 BPSK 信号估计 PN 码。
