本文選題：雙通道 + DDS�。� 參考：《電子科技大學(xué)》2017年碩士論文

【摘要】：伴隨著數(shù)字電路和軟件無線電的發(fā)展,在現(xiàn)代雷達(dá)電子戰(zhàn)中,寬帶雷達(dá)信號(hào)以其良好的目標(biāo)檢測(cè)和識(shí)別能力以及抗各種有源無源干擾,而備受各國的重視。不僅如此,在電子戰(zhàn)中還需要寬帶雷達(dá)能夠產(chǎn)生頻率捷變和任意波形輸出的能力。在某些情況下,還要求具備多通道輸出幾種不同信號(hào)的能力。與此同時(shí),作為雷達(dá)波形產(chǎn)生的關(guān)鍵技術(shù)——DDS得到了廣泛的應(yīng)用,基于可編程的數(shù)字波形產(chǎn)生器具有穩(wěn)定性高、參數(shù)可調(diào)、多種波形輸出的能力。因此對(duì)寬帶雙通道波形產(chǎn)生模塊的研究具有非常重要的意義。本文在深入研究和分析了兩種不同的DDS工作原理和誤差模型以及三種產(chǎn)生中頻信號(hào)的方法之后,提出了基于直接數(shù)字波形合成技術(shù),采用數(shù)字基帶+數(shù)字正交調(diào)制的方式進(jìn)行波形設(shè)計(jì)。本文在FPGA內(nèi)不僅采用了多相濾波和多相NCO的多路并行結(jié)構(gòu)進(jìn)行降采樣處理,同時(shí)還利用了Altera提供的片上系統(tǒng)NIOS Ⅱ?qū)Σㄐ螀?shù)控制,增加系統(tǒng)的靈活性。最后對(duì)設(shè)計(jì)的方案進(jìn)行功能仿真,包括延時(shí)和同步性,不同帶寬,不同中心頻率以及不同信號(hào)形式,測(cè)試結(jié)果完全符合設(shè)計(jì)指標(biāo),證明了本設(shè)計(jì)模塊實(shí)現(xiàn)了寬帶雙通道波形輸出。本文的主要工作分為以下幾點(diǎn):1、介紹了雷達(dá)信號(hào)處理的一些基本理論,并分析了DDS的工作原理和誤差模型以及中頻線性調(diào)頻信號(hào)的產(chǎn)生方法。2、研究了多相濾波和多相NCO的結(jié)構(gòu),在此基礎(chǔ)上分析驗(yàn)證了多路并行結(jié)構(gòu)代替內(nèi)插的可行性。3、介紹了NIOS Ⅱ處理器內(nèi)核,研究和分析了運(yùn)用NIOS Ⅱ技術(shù)進(jìn)行軟核設(shè)計(jì)開發(fā)的流程。4、提出了寬帶雙通道波形產(chǎn)生的基本框架結(jié)構(gòu),完成了對(duì)器件的選擇,方案的設(shè)計(jì)以及方案可行性驗(yàn)證分析。5、實(shí)現(xiàn)了對(duì)各個(gè)軟硬件模塊進(jìn)行仿真驗(yàn)證,以及對(duì)整個(gè)系統(tǒng)的測(cè)試,包括同步性、帶寬、中心頻率和信號(hào)形式,并對(duì)結(jié)果進(jìn)行了技術(shù)指標(biāo)的分析。
[Abstract]:With the development of digital circuits and software radio, wideband radar signals have attracted much attention in modern radar electronic warfare because of their good target detection and recognition ability and anti-active passive interference. Moreover, the ability of wideband radar to generate frequency agility and arbitrary waveform output is required in electronic warfare. In some cases, the ability to output several different signals via multiple channels is also required. At the same time, as the key technology of radar waveform generation, DDS has been widely used. Based on programmable digital waveform generator, it has the ability of high stability, adjustable parameters and output of various waveforms. Therefore, the research of broadband dual channel waveform generation module is of great significance. After deeply studying and analyzing two different working principles and error models of DDS and three methods to generate intermediate frequency signals, a direct digital waveform synthesis technique is proposed in this paper. The waveform is designed by digital baseband digital quadrature modulation. In this paper, we not only use multi-phase filter and multi-channel parallel structure of multi-phase NCO for de-sampling processing in FPGA, but also use the on-chip system NIOS 鈪，

本文編號(hào)：1861207