基于平滑RAT的多相码信号参数估计

摘要

Aiming at the problem that the noise seriously affects the estimated performance when the Radon-Ambiguity transform( RAT) estimates the modulated parameter of polyphase coded radar signals ( Frank, P1,P2,P3 and P4), this paper proposes a polyphase coded signals parameter estimation algorithm based on the smoothed Radon-Ambiguity transform. Firstly,the reason that noise seriously affects the estimated performance of RAT is analyzed in theory, and then the noise basement envelope is estimated through the double smoothing. Finally,the modulated parameter estimation of polyphase coded signals is accomplished in the RAT plane where the noise basement has been eliminated. Simulation experiment results show that the proposed method’s parameter estimation SNR threshold of frequency modulation slope and the code-width has reduced by 1 dB and 4 dB compared with traditional RAT respectively.%针对Radon-ambiguity变换( RAT)在估计多相码信号( Frank码、P1、P2、P3、P4码)调制参数时受噪声影响严重的问题，提出了基于平滑Radon变换的多相码信号参数估计方法。首先理论上分析了噪声影响多相码信号RAT估计性能的原因，进而通过二次平滑估计出信号RAT的噪声基底包络，最后在去除噪声基底的RAT平面中完成多相码信号调制参数的估计。仿真实验表明，该方法调频率和码元宽度估计的信噪比门限相比传统RAT方法分别降低了1 dB和4 dB。