發(fā)布時間：2018-07-17 22:11

【摘要】：隨著信息的快速傳遞,人們對通信功能提出了更多需求,然而現(xiàn)有的頻帶資源越來越稀缺,為了滿足多種速率的數(shù)據(jù)傳輸,可變速率擴頻通信技術(shù)就成為了近年來無線通信的研究熱點之一。論文主要研究了連續(xù)可變速率直擴通信中的關(guān)鍵技術(shù),提出了基于逐符號處理的分數(shù)倍擴頻方案,驗證了矩輔助干擾抑制技術(shù)對常見窄帶干擾信號的抑制能力,最后在uSDR軟件無線電平臺上進行了性能測試,主要工作如下:第一,分數(shù)倍擴頻方案設(shè)計。首先調(diào)研了已有的兩種可變速率擴頻方案,對多碼正交擴頻方案和可變處理增益正交擴頻方案進行了對比,提出了逐符號處理的分數(shù)倍擴頻技術(shù),在信道帶寬保持不變的前提下,實現(xiàn)了信息速率的連續(xù)變化。第二,矩輔助干擾抑制技術(shù)。通過對直擴系統(tǒng)中常見的窄帶干擾類型和干擾抑制方法調(diào)研,提出了復雜度低、干擾抑制能力強的矩輔助干擾抑制技術(shù)。驗證了系統(tǒng)對單音干擾、數(shù)字調(diào)制干擾、高斯帶通干擾信號的抑制能力。第三,鏈路總體設(shè)計。根據(jù)功能與性能需求,對通信鏈路進行了總體設(shè)計,給出了關(guān)鍵模塊的詳細設(shè)計方案。主要包括擴頻技術(shù)、數(shù)字中頻技術(shù)、矩輔助干擾抑制技術(shù)以及同步跟蹤技術(shù)。在Simulink上搭建全鏈路仿真模型,測試了系統(tǒng)在不同干擾類型,干信比為45dB和40dB下的干擾抑制能力。仿真結(jié)果表明,在信息速率為10Kbps,在干信比為45dB時,相比于無干擾場景,性能損失低于2dB。在干信比為40dB時,相比于無干擾場景,性能損失低于1.8dB。第四,在圖形化開發(fā)工具System Generator上完成了鏈路的整體實現(xiàn)。采用FPGA自頂而下的原則,對發(fā)射端和接送端每一模塊實現(xiàn)過程進行了詳細介紹。在uSDR平臺上進行了同步測試和誤碼率測試,實測結(jié)果比無干擾性能損失大約3dB,說明整體實現(xiàn)方案是合理與可行的。本文提出的逐符號處理的擴頻方案具有較強的實用性,并且解決了傳統(tǒng)擴頻通信技術(shù)僅僅局限于整數(shù)倍擴頻增益的問題,為后續(xù)直擴通信的研究提供了參考。
[Abstract]:With the rapid transmission of information, people put forward more requirements for the communication function. However, the existing frequency band resources are becoming more and more scarce, in order to meet the needs of multi-rate data transmission, Variable rate spread spectrum communication technology has become one of the hotspots of wireless communication in recent years. In this paper, the key technologies of continuous variable rate direct spread spectrum communication are studied, and a fractional multiple spread spectrum scheme based on symbol processing is proposed, which verifies the ability of moment assisted interference suppression technology to suppress common narrowband interference signals. Finally, the performance test is carried out on uSDR software radio platform. The main work is as follows: first, the design of fractional multiple spread spectrum scheme. First of all, two kinds of variable rate spread spectrum schemes are investigated, and the multi-code orthogonal spread spectrum scheme and the variable processing gain orthogonal spread spectrum scheme are compared, and a symbol-by-symbol fractional doubling spread spectrum technique is proposed. The continuous change of the information rate is realized on the premise that the channel bandwidth remains unchanged. Second, moment-assisted interference suppression technology. Based on the investigation of common narrowband interference types and interference suppression methods in DSSS systems, a moment assisted interference suppression technique with low complexity and strong interference suppression ability is proposed. The ability of the system to suppress single tone interference, digital modulation interference and Gao Si bandpass interference is verified. Third, the overall design of the link. According to the requirement of function and performance, the overall design of communication link is carried out, and the detailed design scheme of key module is given. It mainly includes spread spectrum technology, digital intermediate frequency technology, moment-assisted interference suppression technology and synchronous tracking technology. The full-link simulation model is built on Simulink, and the interference suppression ability of the system is tested under different interference types and dry signal ratio of 45dB and 40dB. The simulation results show that the performance loss is less than 2 dB when the information rate is 10 kbpsand the dry signal ratio is 45 dB. When the dry signal ratio is 40 dB, the performance loss is less than 1.8 dB compared to the non-interference scenario. Fourth, the overall implementation of the link is completed on the graphical development tool system Generator. Based on the principle of top-down FPGA, the implementation process of each module in transmitter and receiver is introduced in detail. Synchronization test and bit error rate test are carried out on the uSDR platform. The measured results show that the performance loss is about 3 dB compared with that of no interference, which shows that the overall implementation scheme is reasonable and feasible. The symbol-by-symbol spread spectrum scheme proposed in this paper has strong practicability, and solves the problem that the traditional spread spectrum communication technology is only limited to integer multiple spread spectrum gain, which provides a reference for the further study of direct spread spectrum communication.
【學位授予單位】：電子科技大學
【學位級別】：碩士
【學位授予年份】：2016
【分類號】：TN914.42

【參考文獻】

相關(guān)期刊論文 前6條

1 林婧;王宏;方煒;余鐘源;劉元安;;軟件無線電的研究現(xiàn)狀綜述[J];計算機測量與控制;2011年10期

2 馮振偉;武小冬;梅順良;;基于FPGA的數(shù)字中頻接收機設(shè)計與實現(xiàn)[J];通信技術(shù);2010年04期

3 董智紅;吳嗣亮;;大多普勒偏移下直接序列擴頻信號捕獲新方法[J];系統(tǒng)工程與電子技術(shù);2008年08期

4 梁繼業(yè),王海江,梁旭文,楊根慶;CDMA通信中干擾抑制的自適應非線性LTJ濾波技術(shù)[J];電子與信息學報;2005年04期

5 王紅線,李明,周月臣;適于上行鏈路的一種多速率傳輸方案[J];電力系統(tǒng)通信;2002年08期

6 薛筱明,李建東;多進制正交碼擴頻系統(tǒng)的解擴和同步技術(shù)及其實現(xiàn)[J];電子學報;1998年01期

相關(guān)碩士學位論文 前2條

1 徐立;衛(wèi)星導航接收機時頻聯(lián)合干擾抑制算法研究[D];電子科技大學;2008年

2 劉曉燕;雙星定位系統(tǒng)中擴頻碼同步技術(shù)研究及FPGA實現(xiàn)[D];西北工業(yè)大學;2005年

，

本文編號：2131084