线性调频脉冲信号超低旁瓣脉压器设计及FPGA实现
摘要脉冲压缩技术(Pulse Compression，PC)是一种在现代雷达系统中广泛应用的技术，回波信号经匹配处理，宽脉冲压缩为短脉冲，这提高了系统信噪比及距离分辨力、分辨精度，解决了探测距离与距离分辨力间的矛盾。但常规脉压方法输出旁瓣高，易造成虚警，需进行旁瓣抑制，且旁瓣抑制也会带来信噪比损失与主瓣展宽。本文旨在设计满足指标的低旁瓣脉压器并进行FPGA实现。
本文首先讨论了匹配脉压、窗函数加权旁瓣抑制、谱修正法旁瓣抑制、网络综合法旁瓣抑制及凸优化失配脉压这几种方法，并进行了仿真，对它们的旁瓣抑制性能进行了比较。最后使用凸优化方法设计了满足信噪比损失、主瓣展宽及旁瓣要求的失配脉压滤波器，得到了低于60dB的超低旁瓣。相比于传统方法，损失可控，旁瓣更低。75461
最后完成了低旁瓣脉压器的FPGA实现。通过信号产生板产生了线性调频脉冲信号，并在信号处理板上进行了脉冲压缩处理，中间经ADC采样与数字下变频及失配脉压滤波器，得到了与仿真结果符合的实现结果。
毕业论文关键词 脉冲压缩 旁瓣抑制 凸优化 谱修正 网络综合 FPGA实现
毕业设计说明书外文摘要
Title An Ultra-Low Sidelobe Pulse Compression Filter of Linear Frequency Modulation Pulse Signal and FPGA Realization
Abstract Pulse compression is a widely used technology in modern radar system。 The echo signal go through matched filter, this makes pulse width become short, improves the system’s SNR and distance resolution, solve the contradiction between radar detection distance and distance resolution。 Conventional pulse compression method output a high sidelobe, which is easy to cause false alarm。 So wo should suppress sidelobe。 But this also leads SNR loss and mainlobe broaden。 This paper aims to design an ultra-low sidelobe suppression filter, and realize it on FPGA。
Firstly, the paper discusses the matching pulse compression, and sidelobe suppression with window weighting, spectrum correcting, network synthesis and convex optimization。 It gives the simulation result and compares their properties。 Finally, the convex optimization method is used to solve the problem which meets the requirement of SNR loss ,mainlobe width and sidelobe height。 The filter finally output an ultra-low sidelobe which is lower than 60dB。Commpared to the traditional methods, the loss is under control and sidelobe becomes lower。
Finally, the paper completed the FPGA realization。 The linear frequency modulation pulse signal is generated by the signal generator, and pulse compression processing is on the signal processing board。 The result finally come out after ADC sampling, digital down-conversion and pulse compression。 It meets the simulation result。
Keywords Pulse compression, Sidelobe suppression, Convex optimization, Spectrum correcting, Network synthesis, FPGA realization
目 次
1 引言 1
1。1 研究背景、目的及意义 1
1。3 论文的主要工作及内容安排 2
2 线性调频脉冲信号及仿真 4
2。1 线性调频信号概述 4
2。2 线性调频脉冲信号的产生 8
2。3 本章小结 9
3 脉冲压缩及旁瓣抑制 10
3。1 引言