一种提高脉冲信号测频精度的方法

以短时脉冲信号为研究对象,推导了FFT测频方法精度与脉冲时宽的关系式,指出了使用传统FFT测频方法的不足之处。研究了插值FFT法提高测频精度的原理,分析了在噪声背景下,由于插值方向错误对测频精度的不利影响。探讨了加窗情况下插值FFT方法的抗噪声性能,给出了基于汉宁窗的插值算法,通过仿真验证了其降低测频误差的效果。分析了算法的可实现性,并给出了基于FPGA的全数字实现流程。最后对应用此算法的侦察接收机进行了测试,结果满足指标要求。

An Algorithm for Improving Frequency Measurement Accuracy of Pulse Signal

This paper, based on short time pulse signal, deduces the relation between FFT frequency t accuracy and pulse duration, analyzes the deficiencies of FFT frequency measurement.The principle of improving the measurement accuracy by inter- polation FFT is studied, and the adverse effect on frequency measurement accuracy caused by the interpolation direction error under the background of noise is analyzed.This paper explores the anti-noise performance of interpolation after windowed, presents the interpola- tion algorithm used hanning window.The effect of decreasing error is validated by simulation.The feasibility of this algorithm is analyzed, and the digital implementation based on FPGA is given.Finally the reconnaissance receiver which uses the algorithm is tested, and the results show that the requirements are satisfied.