【正文】 本 科 畢 業(yè) 設(shè) 計(jì) （ 論 文 ）題目 基于 MATLAB 的信號(hào)檢測與 解調(diào)技術(shù)研究學(xué)生姓名 滕 冬 明 學(xué)　號(hào) 0607050116教學(xué)院系 電子信息工程學(xué)院專業(yè)年級 通信工程 2022 級指導(dǎo)教師 鄭 勉 職　稱 講 師單　　位 電子信息工程學(xué)院輔導(dǎo)教師 職 稱單　　位完成日期 2022 年 6 月 6 日 Southwest Petroleum University Graduation ThesisThe Signal Detection and DemodulationStudy Based on MATLABGrade: 2022Name: Teng Dong MingSpeciality: Telemunications EngineeringInstructor: Zheng MianSchool of Electronic Information Engineering202266I摘要本文通過對信號(hào)檢測調(diào)制的了解，發(fā)現(xiàn)信號(hào)的檢測前需要進(jìn)行信號(hào)的過濾，濾除無用的噪聲，解調(diào)的時(shí)候需要用濾波器選出需要的信號(hào)頻率。也可以理解為信號(hào)的檢測就是消除噪聲，信號(hào)的解調(diào)就是選出發(fā)送端所需傳輸和接收的原始信號(hào)。因此我們?yōu)榱烁玫貙π盘?hào)檢測與解調(diào)，在解調(diào)前需要對信號(hào)進(jìn)行很好的過濾。一個(gè)好的濾波器就顯得非常重要了。在文中，我們研究了在 MATLAB 環(huán)境下 IIR 濾波器一般設(shè)計(jì)方式和完全設(shè)計(jì)方式。一般設(shè)計(jì)方式先按一定規(guī)則將給出的數(shù)字濾波器的技術(shù)指標(biāo)轉(zhuǎn)換成模擬低通濾波器的技術(shù)指標(biāo)，據(jù)此產(chǎn)生模擬濾波器原型。然后把模擬低通濾波器原型轉(zhuǎn)換成模擬低通、高通、帶通、帶阻濾波器，最后再把模擬濾波器轉(zhuǎn)換成數(shù)字濾波器。完全設(shè)計(jì)方式是我們利用函數(shù)直接設(shè)計(jì)出低通、高通、帶通和帶阻濾波器，并分別用巴特沃斯(Butterworth)濾波器、切比雪夫(chebyshev)濾波器、橢圓(Cauer) 濾波器來實(shí)現(xiàn)。在 FIR 濾波器的設(shè)計(jì)中，我們主要運(yùn)用窗函數(shù)進(jìn)行設(shè)計(jì)，通過不同的窗函數(shù)進(jìn)行比較，找出各種窗函數(shù)設(shè)計(jì)濾波器的優(yōu)缺點(diǎn)。接著就是進(jìn)行濾波器的實(shí)驗(yàn)，也是本論文的主要目的。通過不同的濾波器對信號(hào)進(jìn)行檢測，解調(diào)恢復(fù)出原始信號(hào)。文中我們模擬了在信號(hào)檢測時(shí)對隨機(jī)噪聲的清除，模擬了解調(diào)時(shí)對原始信號(hào)的篩選，對比不同的濾波器，選出適合的濾波器，并比較了 IIR 和 FIR 濾波器的優(yōu)劣。關(guān)鍵詞：信號(hào)檢測；解調(diào)；數(shù)字濾波器；恢復(fù)IIAbstractBased on the study of modem signal detection, before signal detection, we should filter useless noise， and we also should use Filter to slecte needed signal frequency in demodulation. And this can be understood as the elimination of noise, signal demodulation is selected what need to be transported from the sending endand the original signal to be recepted. So,signal must be filtered before the demodulation just for a better detection and , a good filter is very important. In the paper, we studied the general and pletely design under the circumstances of MATLAB and IIR filter. General design is to convert digital filter’s technology index into lowpass filter’s technology index According to certain rules,and then based on which to produce the prototype of analog filter. Then converted the analog lowpass filter prototype into analog lowpass, qualm, bandpass, bandstop filters, then transform the simulation filter into digital filter. And then we use the Butterworth filter, chebyshev filter, elliptic filter to realize the function respectively. In the design of FIR filters, we mainly use window function design and pare, and we find out the advantages and disadvantages of the filter.The main purpose of this paper is the experiment of filter,. Then we should detecte to signal and restore the original signal by demodulation on different filter.. In the paper, we simulated the elimilation of random noise in signal detection, filter of original signal in demodulation, paring the different filter ,choose suitable filter, and pared with IIR and FIR filters.Key words: signal detection 。demodulator 。 digital filter 。restore III目錄摘要 ........................................................................................................................................IABSTRACT ..........................................................................................................................II1 緒論 ....................................................................................................................................12 信號(hào)檢測解調(diào)的方式 ........................................................................................................2 信號(hào)的檢測的方式 ......................................................................................................2 信號(hào)解調(diào)方式 ..............................................................................................................53 信號(hào)檢測與解調(diào)的工具—— 濾波器 ................................................................................7 濾波器的發(fā)展 ..............................................................................................................7 數(shù)字濾波器的設(shè)計(jì)要求和方法 ..................................................................................8 數(shù)字濾波器設(shè)計(jì)方法概述 ..........................................................................................94 IIR 濾波器和 FIR 濾波器的設(shè)計(jì) ....................................................................................10 IIR 濾波器的設(shè)計(jì) ......................................................................................................10 濾波器的直接設(shè)計(jì) ........................................................................................10 濾波器的間接設(shè)計(jì) ........................................................................................10 完全濾波器設(shè)計(jì) ..................................................................................................13 IIR 數(shù)字濾波器的設(shè)計(jì)實(shí)例 ...............................................................................16 FIR 濾波器的設(shè)計(jì) .....................................................................................................18 窗函數(shù)法設(shè)計(jì) FIR 濾波器 ..................................................................................18 帶過渡帶的多帶 FIR 濾波器設(shè)計(jì) ......................................................................255 信號(hào)檢測與解調(diào)的目的—— 恢復(fù)信號(hào) ..........................................................................29 用 IIR 和 FIR 濾波器恢復(fù)信號(hào) .................................................................................29 兩種濾波器對隨機(jī)信號(hào)的濾除效果 ..................................................................29 兩種濾波器對指定頻率信號(hào)的濾除效果 ..........................................................33 濾波器對高頻信號(hào)的恢復(fù) ..................................................................................37 IIR 與 FIR 數(shù)字濾波器的比較 ..................................................................................39 IIR 濾波器特點(diǎn) ...................................................................................................39 濾波器特點(diǎn) ....................................................................................................40 兩種濾波器的設(shè)計(jì)方法比較 ..............................................................................406 結(jié)論 .....................................................................................................................