【摘要】：高速發(fā)展的無線通信業(yè)務(wù)導(dǎo)致無線頻譜資源日益緊張,因此,具有高效頻譜資源利用率的新型無線通信技術(shù)一直是研究的熱點(diǎn)。作為高時(shí)間利用率無線通信技術(shù)的典型代表,認(rèn)知無線電通過引入動態(tài)頻譜接入機(jī)制,有效的提高了頻譜利用率。頻譜可控的直擴(kuò)通信技術(shù)不僅具有擴(kuò)頻通信的優(yōu)勢,同時(shí)能夠生成具有零陷特征的頻譜,且該零陷特征可控,將其作為認(rèn)知無線電的具體實(shí)現(xiàn)技術(shù),可有效降低認(rèn)知用戶頻譜接入時(shí)對于授權(quán)用戶的干擾,同時(shí)保證認(rèn)知用戶自身的通信性能。通過兩者的結(jié)合,可構(gòu)建一種新型的認(rèn)知無線通信系統(tǒng)——頻譜可控的直擴(kuò)認(rèn)知通信系統(tǒng)。本文針對頻譜可控的直擴(kuò)認(rèn)知通信系統(tǒng)關(guān)鍵技術(shù)進(jìn)行研究,并結(jié)合壓縮感知理論在認(rèn)知無線電和擴(kuò)頻通信中的應(yīng)用,做了如下的研究工作:(1)對于認(rèn)知無線電的寬帶頻譜感知,基于壓縮感知理論的壓縮寬帶頻譜感知方法是解決系統(tǒng)前端高采樣率需求問題的有效方案。而在壓縮寬帶頻譜感知中,對于頻譜稀疏度的依賴阻礙了該技術(shù)在實(shí)際中的廣泛應(yīng)用,針對該問題,提出一種稀疏度自適應(yīng)的壓縮采樣匹配追蹤算法(SACoSaMP),并給出該算法能夠精確重構(gòu)稀疏信號的理論分析。所提算法不依賴于信號真實(shí)稀疏度,且具有較好的重構(gòu)效果,將其應(yīng)用于壓縮寬帶頻譜感知中,能有效實(shí)現(xiàn)稀疏度未知情況下的頻譜檢測。(2)為了獲得頻譜可控的擴(kuò)頻序列,借鑒mW復(fù)合序列思路,分別提出基于譜零陷碼的頻譜可控復(fù)合序列和基于塊編碼的頻譜可控復(fù)合序列,推導(dǎo)復(fù)合序列功率譜表達(dá)式,分析其頻譜可控性及頻譜特征與序列參數(shù)、序列復(fù)合方式的對應(yīng)關(guān)系,給出所需頻譜形狀的設(shè)計(jì)方法,分析比較各復(fù)合序列的特性。構(gòu)建直擴(kuò)認(rèn)知通信系統(tǒng),采用所提出的復(fù)合序列實(shí)現(xiàn)認(rèn)知用戶的頻譜接入,分析系統(tǒng)中授權(quán)用戶和認(rèn)知用戶的誤碼率性能。(3)針對mW復(fù)合序列的參數(shù)估計(jì)問題,分別提出采用其頻譜和循環(huán)譜來實(shí)現(xiàn)參數(shù)的估計(jì)。為了降低頻譜獲取所需采樣率,采用調(diào)制寬帶轉(zhuǎn)換(MWC)來重構(gòu)信號頻譜,通過檢測頻譜峰值來實(shí)現(xiàn)mW復(fù)合序列中Walsh序列序號及信號載頻的估計(jì)。為了提升估計(jì)性能,推導(dǎo)mW復(fù)合序列的循環(huán)譜表達(dá)式,給出循環(huán)譜切面峰值位置與復(fù)合序列參數(shù)的對應(yīng)關(guān)系。針對mW復(fù)合序列循環(huán)譜獲取所需采樣率高的問題,采用壓縮循環(huán)譜理論重構(gòu)信號循環(huán)譜,并通過檢測循環(huán)譜切面峰值來實(shí)現(xiàn)mW復(fù)合序列中Walsh序列序號、m序列碼片速率和信號載頻的估計(jì)。(4)為了利用復(fù)合序列所具有的特征來提升擴(kuò)頻接收機(jī)的性能,介紹一種新型的壓縮擴(kuò)頻接收機(jī)。該接收機(jī)從擴(kuò)頻信號所具有的稀疏性角度出發(fā),通過壓縮感知理論來實(shí)現(xiàn)擴(kuò)頻信號的接收,結(jié)構(gòu)極其簡單,但誤碼率性能較傳統(tǒng)的相關(guān)接收機(jī)有所下降。在復(fù)合序列參數(shù)估計(jì)方法研究的基礎(chǔ)上,提出基于支撐集估計(jì)的壓縮擴(kuò)頻接收機(jī),該接收機(jī)首先通過對接收信號的參數(shù)估計(jì)獲得待重構(gòu)信號的支撐集,然后利用估計(jì)的支撐集來提升壓縮擴(kuò)頻接收機(jī)的誤碼率性能。
[Abstract]:With the rapid development of wireless communication services, wireless spectrum resources are increasingly scarce. Therefore, new wireless communication technologies with high efficiency of spectrum resource utilization have been the focus of research. Utilization rate. Spectrum-controllable DS/SS communication technology not only has the advantage of spread spectrum communication, but also can generate spectrum with zero-pitch feature, and the zero-pitch feature is controllable. As a specific implementation technology of cognitive radio, it can effectively reduce the interference of cognitive users to authorized users when spectrum access, while ensuring the cognitive users themselves. Communication performance. A new cognitive wireless communication system, spectrum-controllable DSSS cognitive communication system, can be constructed by combining the two. In this paper, the key technologies of spectrum-controllable DSSS cognitive communication system are studied, and the application of compressed sensing theory in cognitive radio and spread spectrum communication is studied as follows. Work: (1) Compressed broadband spectrum sensing based on compressed sensing theory is an effective solution to the problem of high sampling rate in front of the system for cognitive radio. A sparsity adaptive compression sampling matching pursuit algorithm (SACoSaMP) is proposed and the theoretical analysis of the algorithm is given. The proposed algorithm does not depend on the true sparsity of the signal, and has a good reconstruction effect. It can be applied to compressed broadband spectrum sensing to effectively realize sparsity unknown. (2) In order to obtain a spectrum-controllable spread spectrum sequence, a spectrum-controllable composite sequence based on spectrum null-notch code and a spectrum-controllable composite sequence based on block coding are proposed, respectively. The power spectrum expression of the composite sequence is deduced, and its spectrum controllability, spectrum characteristics and sequence parameters are analyzed. According to the corresponding relationship, the design method of spectrum shape is given, and the characteristics of each complex sequence are analyzed and compared. A DS-SS cognitive communication system is constructed. The spectrum access of cognitive users is realized by using the proposed complex sequence. The BER performance of authorized users and cognitive users in the system is analyzed. (3) For the problem of parameter estimation of mW composite sequence, the system is divided into two parts. In order to reduce the sampling rate needed for spectrum acquisition, the modulation broadband conversion (MWC) is used to reconstruct the signal spectrum, and the Walsh sequence number and the carrier frequency of the signal are estimated by detecting the peak value of the spectrum. To solve the problem of high sampling rate in obtaining cyclic spectrum of mW composite sequence, the cyclic spectrum of signal is reconstructed by compressed cyclic spectrum theory, and the sequence number, chip rate and sum of Walsh sequences in mW composite sequence are realized by detecting the peak value of cyclic spectrum section. (4) In order to improve the performance of spread spectrum receiver by utilizing the characteristics of composite sequence, a new compressed spread spectrum receiver is introduced. The receiver is based on the sparsity of spread spectrum signal and the theory of compressed sensing. The structure of the receiver is very simple, but the BER performance is very good. Compressed spread spectrum receiver based on support set estimation is proposed. The support set of the reconstructed signal is obtained by estimating the parameters of the received signal, and then the error of the compressed spread spectrum receiver is improved by using the estimated support set. Rate performance.
【學(xué)位授予單位】：哈爾濱工程大學(xué)
【學(xué)位級別】：博士
【學(xué)位授予年份】：2016
【分類號】：TN914.42;TN925

【相似文獻(xiàn)】

相關(guān)期刊論文 前10條

1 張長棉;一種鐘控復(fù)合序列[J];通信保密;1988年01期

2 杜秀麗;甄旭亮;陳波;;基于混沌復(fù)合序列的直擴(kuò)系統(tǒng)及其性能分析[J];計(jì)算機(jī)仿真;2013年11期

3 王輝;郭黎利;;基于碼位移的復(fù)合序列擴(kuò)頻通信認(rèn)知無線電信道兼容技術(shù)[J];自動化技術(shù)與應(yīng)用;2013年04期

4 付江志;郭黎利;楊紅喬;;基于復(fù)合序列的多進(jìn)制正交擴(kuò)頻系統(tǒng)性能分析[J];系統(tǒng)工程與電子技術(shù);2010年04期

5 郭黎利;一種頻譜結(jié)構(gòu)可控的復(fù)合序列擴(kuò)頻通信方式[J];船舶工程;1999年01期

6 吳永海,郭黎利;mW復(fù)合序列在擴(kuò)頻通信中抗遠(yuǎn)近效應(yīng)的應(yīng)用[J];哈爾濱工程大學(xué)學(xué)報(bào);2001年05期

7 郭黎利;具有 DS/FH 頻譜特性的復(fù)合序列擴(kuò)頻通信方式[J];哈爾濱工程大學(xué)學(xué)報(bào);1998年04期

8 郭黎利;付江志;崔永生;楊紅喬;;采用m-W復(fù)合序列的直擴(kuò)系統(tǒng)規(guī)避窄帶干擾的研究[J];哈爾濱工程大學(xué)學(xué)報(bào);2010年05期

9 劉杰;李艷斌;;直擴(kuò)通信最佳干擾形式分析[J];無線電通信技術(shù);2001年06期

10 董占奇;胡捍英;;隱蔽直擴(kuò)通信研究[J];無線電通信技術(shù);2006年04期

相關(guān)會議論文 前5條

1 張剛強(qiáng);宋軍;劉平香;;一種改進(jìn)的M元差分直擴(kuò)水聲通信系統(tǒng)[A];中國聲學(xué)學(xué)會水聲學(xué)分會2013年全國水聲學(xué)學(xué)術(shù)會議論文集[C];2013年

2 張偉;唐斌;張健;周R，

本文編號：2199960