低軌衛(wèi)星信道模擬器設計與實現(xiàn)
發(fā)布時間：2019-01-02 07:32
【摘要】：低軌衛(wèi)星移動通信系統(tǒng)運行軌道低、傳輸時延小和終端要求低等特點已使其成為衛(wèi)星通信系統(tǒng)的一個主要發(fā)展方向。在低軌衛(wèi)星移動通信系統(tǒng)中,信號會受多普勒效應、陰影效應、多徑效應和傳播噪聲等因素的影響。所以,在低軌衛(wèi)星移動通信系統(tǒng)的研發(fā)過程中,為了驗證系統(tǒng)的可靠性,必須要了解低軌衛(wèi)星信道對系統(tǒng)信號所產(chǎn)生的影響。在以往,人們大多采用外場試驗的方法,租用實際衛(wèi)星鏈路進行測試,但這種方法代價高昂且易受外界因素影響。所以,本課題設計了一種基于DSP的低軌衛(wèi)星信道模擬器,該信道模擬器能夠在實驗室條件下實時模擬低軌衛(wèi)星信道的傳輸特性,為低軌衛(wèi)星移動通信系統(tǒng)的研制提供測試方法,具有重要的實際意義。 本文主要工作包括以下內(nèi)容： (1)通過分析比較幾種常用衛(wèi)星信道模型,選擇了IMS (Land Mobile Satellite)模型作為本低軌衛(wèi)星信道模擬器的理論模型。 (2)針對LMS模型,提出了本低軌衛(wèi)星信道模擬器的實現(xiàn)結構框圖,并利用Simulink對其中的數(shù)字下變頻系統(tǒng)進行了仿真,仿真結果驗證了數(shù)字下變頻系統(tǒng)中抽取濾波器的性能,為實際開發(fā)中數(shù)字下變頻(DDC)芯片的參數(shù)設置提供了數(shù)據(jù)驗證。 (3)提出了一種結合專用數(shù)字下變頻芯片AD6620和DSP的低軌衛(wèi)星信道模擬器實現(xiàn)方案。設計了一塊中頻處理子卡,再結合SEED-DEC6713開發(fā)板,,完成了本低軌衛(wèi)星信道模擬器的硬件設計,并對各模塊及模塊間的具體電路設計進行了詳細介紹。 (4)利用AD6620濾波器設計軟件Fltrdsn得到了濾波器的最優(yōu)抽取率組合,使用單片機AT89LV51完成了對AD6620的初始化設置,并給出了TMS320C6713與AD6620的接口程序及信號處理程序的設計。 (5)搭建了系統(tǒng)測試平臺,利用信號發(fā)生器為系統(tǒng)提供模擬中頻測試信號,然后通過CCS (Code Composer Studio)軟件對測試結果進行觀測與分析,測試結果表明,本低軌衛(wèi)星信道模擬器能夠模擬衛(wèi)星移動通信信道的衰落和多普勒頻移效應,達到了預期的設計目標。
[Abstract]:Low orbit satellite mobile communication system has become a main developing direction of satellite communication system due to its low orbit, low transmission delay and low terminal requirements. In Leo satellite mobile communication system, the signal is affected by Doppler effect, shadow effect, multipath effect and propagation noise. Therefore, in the research and development of Leo satellite mobile communication system, in order to verify the reliability of the system, it is necessary to understand the influence of Leo satellite channel on the system signal. In the past, people mostly used the method of field test to rent the actual satellite link for test, but this method is expensive and easy to be affected by external factors. Therefore, this paper designs a Leo satellite channel simulator based on DSP. The channel simulator can simulate the transmission characteristics of Leo satellite channel in real time under laboratory conditions, and provide a test method for the development of Leo satellite mobile communication system. It has important practical significance. The main work of this paper is as follows: (1) by analyzing and comparing several commonly used satellite channel models, IMS (Land Mobile Satellite) model is selected as the theoretical model of the Leo satellite channel simulator. (2) based on the LMS model, the implementation block diagram of the Leo satellite channel simulator is proposed, and the digital downconversion system is simulated by Simulink. The simulation results verify the performance of the decimation filter in the digital downconversion system. It provides the data verification for the parameter setting of the digital down conversion (DDC) chip in the actual development. (3) an implementation scheme of Leo satellite channel simulator based on AD6620 and DSP is proposed. In this paper, a sub-card of intermediate frequency processing is designed, combined with SEED-DEC6713 development board, the hardware design of the Leo satellite channel simulator is completed, and the specific circuit design of each module and module is introduced in detail. (4) the optimal decimation rate combination of the filter is obtained by using the AD6620 filter design software Fltrdsn, and the initialization setting of the AD6620 is completed by using the single-chip computer AT89LV51. The interface program between TMS320C6713 and AD6620 and the design of the signal processing program are given. (5) the system test platform is built, and the signal generator is used to provide the analog if test signal for the system. Then the test results are observed and analyzed by CCS (Code Composer Studio) software. The test results show that, This Leo satellite channel simulator can simulate the fading and Doppler frequency shift effect of satellite mobile communication channel and achieve the desired design goal.
【學位授予單位】：南京信息工程大學
【學位級別】：碩士
【學位授予年份】：2014
【分類號】：TN927.23
本文編號：2398195
[Abstract]:Low orbit satellite mobile communication system has become a main developing direction of satellite communication system due to its low orbit, low transmission delay and low terminal requirements. In Leo satellite mobile communication system, the signal is affected by Doppler effect, shadow effect, multipath effect and propagation noise. Therefore, in the research and development of Leo satellite mobile communication system, in order to verify the reliability of the system, it is necessary to understand the influence of Leo satellite channel on the system signal. In the past, people mostly used the method of field test to rent the actual satellite link for test, but this method is expensive and easy to be affected by external factors. Therefore, this paper designs a Leo satellite channel simulator based on DSP. The channel simulator can simulate the transmission characteristics of Leo satellite channel in real time under laboratory conditions, and provide a test method for the development of Leo satellite mobile communication system. It has important practical significance. The main work of this paper is as follows: (1) by analyzing and comparing several commonly used satellite channel models, IMS (Land Mobile Satellite) model is selected as the theoretical model of the Leo satellite channel simulator. (2) based on the LMS model, the implementation block diagram of the Leo satellite channel simulator is proposed, and the digital downconversion system is simulated by Simulink. The simulation results verify the performance of the decimation filter in the digital downconversion system. It provides the data verification for the parameter setting of the digital down conversion (DDC) chip in the actual development. (3) an implementation scheme of Leo satellite channel simulator based on AD6620 and DSP is proposed. In this paper, a sub-card of intermediate frequency processing is designed, combined with SEED-DEC6713 development board, the hardware design of the Leo satellite channel simulator is completed, and the specific circuit design of each module and module is introduced in detail. (4) the optimal decimation rate combination of the filter is obtained by using the AD6620 filter design software Fltrdsn, and the initialization setting of the AD6620 is completed by using the single-chip computer AT89LV51. The interface program between TMS320C6713 and AD6620 and the design of the signal processing program are given. (5) the system test platform is built, and the signal generator is used to provide the analog if test signal for the system. Then the test results are observed and analyzed by CCS (Code Composer Studio) software. The test results show that, This Leo satellite channel simulator can simulate the fading and Doppler frequency shift effect of satellite mobile communication channel and achieve the desired design goal.
【學位授予單位】：南京信息工程大學
【學位級別】：碩士
【學位授予年份】：2014
【分類號】：TN927.23
【參考文獻】
相關期刊論文 前10條
1 徐烽;陳鵬;;國外衛(wèi)星移動通信新進展與發(fā)展趨勢[J];電訊技術;2011年06期
2 康士峰,張明高;陸地移動衛(wèi)星通信系統(tǒng)設計中的多徑衰落研究[J];電波科學學報;1997年01期
3 李興,吳詩其;衛(wèi)星移動通信信道LR~2模型及系統(tǒng)性能分析[J];電波科學學報;2003年03期
4 陸迎光,仇潤鶴,孫曉靖;中頻軟件無線電接收機中信號傳輸和處理技術[J];電子技術;2003年11期
5 李家欣,王乘,倪亮;基于AD6620和TMS320C6x的軟件無線電接收子系統(tǒng)[J];電子技術應用;2002年05期
6 肖琨,吳詩其;一種適用于非城市區(qū)域的衛(wèi)星移動信道統(tǒng)計模型[J];電子學報;2002年07期
7 邱晶,余平,楊士中;移動衛(wèi)星通信的信道模型和傳輸特性分析[J];重慶大學學報(自然科學版);2003年07期
8 張乃通,張中兆,初海彬,劉會杰;衛(wèi)星移動通信的現(xiàn)狀與發(fā)展[J];中國工程科學;2002年10期
9 姚瑤;;衛(wèi)星通信在跨區(qū)域應急救援中的應用[J];信息通信;2011年05期
10 郭業(yè)才;章濤;袁濤;;衛(wèi)星信道模擬器數(shù)字下變頻系統(tǒng)設計[J];科學技術與工程;2014年01期
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