基于FPGA的二維OS-CFAR設(shè)計(jì)與實(shí)現(xiàn)

基于FPGA的二維OS-CFAR設(shè)計(jì)與實(shí)現(xiàn)

劉中祥,宋志勇,付強(qiáng)

(國(guó)防科學(xué)技術(shù)大學(xué)電子科學(xué)與工程學(xué)院,長(zhǎng)沙 410073)

摘要：二維OS-CFAR檢測(cè)器在雷達(dá)目標(biāo)檢測(cè)中具有較好的檢測(cè)性能,特別是在多目標(biāo)以及動(dòng)態(tài)雜波環(huán)境中,具有較強(qiáng)的抗干擾目標(biāo)的能力。本文基于FPGA設(shè)計(jì)和實(shí)現(xiàn)了二維OS-CFAR檢測(cè)器,采用并行尋址以及二元積累判決等結(jié)構(gòu)解決了FPGA實(shí)現(xiàn)中二維空間上參考單元尋址困難以及排序運(yùn)算計(jì)算量大、耗時(shí)長(zhǎng)、實(shí)時(shí)性不高的問(wèn)題,實(shí)現(xiàn)了對(duì)距離-多普勒平面內(nèi)所有檢測(cè)點(diǎn)的流水作業(yè),提高了二維有序恒虛警檢測(cè)的實(shí)時(shí)性,滿足了工程應(yīng)用的要求。通過(guò)將FPGA實(shí)現(xiàn)結(jié)果與理論檢測(cè)結(jié)果進(jìn)行比較,驗(yàn)證了本文方法的有效性。

關(guān)鍵詞：二維OS-CFAR;FPGA;數(shù)據(jù)流;二元積累

doi:10.13442/j.gnss.1008-9268.2015.05.014

中圖分類號(hào)：TN957

文獻(xiàn)標(biāo)志碼：A

文章編號(hào)：1008-9268(2015)05-0076-05

收稿日期：2015-05-25

作者簡(jiǎn)介

Abstract:Two-dimensional(2D) Ordered Statistics Constant False Alarm Rate(OS-CFAR) detector usually exhibits good performance in radar target detection. It has good anti-jamming capacity especially in the non-homogeneous environment caused by strong interfering targets and dynamic clutter. In this paper, a 2D OS-CFAR detector is designed and implemented based on FPGA. The structures, including parallel addressing and binary integration decision, are exploited to resolve the problems such as difficulty in reference cell addressing, large computation amount, time consuming and low real-time poverty in the ordering process, which often occur in the implementation process with FPGA. All the points in the Range-Doppler plane are detected in data flow processing and the real-time poverty of the 2D OS-CFAR is improved, which meets the requirements in engineering. A comparison of the experimental results based on FPGA and the theoretical analysis is conducted and demonstrates the effectiveness of the proposed method.

0引言

雷達(dá)恒虛警檢測(cè)器的實(shí)際檢測(cè)性能與其參考背景單元的分布有很大關(guān)系,當(dāng)參考背景是均勻分布時(shí),均值類CFAR具有較好的檢測(cè)性能[1]。但是在多目標(biāo)以及動(dòng)態(tài)雜波環(huán)境下,CA-CFAR的檢測(cè)性能會(huì)隨干擾目標(biāo)點(diǎn)的增加而迅速下降[2],而OS-CFAR具有較好的抗多目標(biāo)干擾的能力,在均勻雜波背景和雜波邊緣環(huán)境中的性能下降也是可以接受的[3]。

由于一維CFAR檢測(cè)器的參考窗在同一維度上,即在距離維或多普勒維上,這樣獲取的背景信息比較單一,得出的檢測(cè)門限精確度較差。因此,為了獲取更多的背景信息,把一維參考窗擴(kuò)展到二維,即同時(shí)選取距離維和多普勒維上的背景信息來(lái)做估計(jì),這樣,總體檢測(cè)性能有更大的提高。……