本文選題：軟件無線電　切入點：電磁環(huán)境監(jiān)測/測向　出處：《電子科技大學》2014年碩士論文　論文類型：學位論文

【摘要】：軟件無線電技術(shù)的迅速發(fā)展帶動了無線電監(jiān)測測向技術(shù)的不斷變革。目前基于軟件無線電架構(gòu)的監(jiān)測系統(tǒng)正朝著數(shù)字化、網(wǎng)絡(luò)化的方向發(fā)展。但隨著通信技術(shù)的不斷更新進步,無線環(huán)境變得越來越復雜,例如多種不同的調(diào)制方式并存和固定帶寬內(nèi)可能存在很多形式復雜且分布密集的信號等,這些都對現(xiàn)有監(jiān)測系統(tǒng)中識別算法識別種類的多樣性,以及測向算法的精度和實時性帶來了極大的挑戰(zhàn)。本文正是以電磁環(huán)境監(jiān)測/測向系統(tǒng)為背景,主要研究內(nèi)容為監(jiān)測任務中多載波和單載波信號的類間識別和正交幅度調(diào)制(QAM)信號的類內(nèi)識別,以及測向任務中的相關(guān)干涉測向算法:1.針對多載波和單載波信號的識別的問題,提出基于帶寬和功率歸一化的功率譜的Kurtosis系數(shù)的正交頻分復用(OFDM)和單載波信號識別的方法,并仿真驗證了該特征參數(shù)在多種條件下魯棒性和識別性能。仿真表明,在SNR=0dB時,OFDM和單載波的正確識別率可達95%以上。2.針對定時誤差和頻偏會引起QAM信號識別率下降的問題,提出一種改善識別性能的方案:首先對接收到的MQAM信號采用OM定時同步和非線性差分處理,最后對信號進行幅度對數(shù)似然識別。仿真結(jié)果表明本文提出的方案對定時誤差和頻偏有很強的適應性,當SNR?12d B,QAM信號平均識別率可以達到98%。3.針對傳統(tǒng)相關(guān)干涉測向算法中測向精度不高和實時性差等問題,提出采用插值擬合的方法來提高測向精度;另外提出對相關(guān)測向的結(jié)構(gòu)進行改進,引入空間角,用一維信息來代替二維空域信息,單就計算量而言,減小了73%的計算量,從而提高了算法的實時性。4.基于FPGA+DSP硬件平臺對雙通道相關(guān)干涉測向處理模塊的工作模式和樣本數(shù)據(jù)庫的存儲,測向處理程序設(shè)計等幾個方面進行了詳細說明。最后對單頻點測向?qū)崿F(xiàn)結(jié)果進行了測向時間和準確度的分析,結(jié)果表明兩者均達到測向指標。
[Abstract]:The rapid development of software radio technology has led to the continuous change of radio monitoring and direction finding technology. At present, the monitoring system based on software radio architecture is developing towards the direction of digitization and networking. But with the development of communication technology, Wireless environment is becoming more and more complex, such as the coexistence of different modulation modes and the existence of many complex and distributed signals in fixed bandwidth. These are the diversity of recognition algorithms in existing monitoring systems. The precision and real time of the direction finding algorithm bring great challenge. This paper is based on the electromagnetic environment monitoring / direction finding system. The main contents of this paper are the inter-class recognition of multi-carrier and single-carrier signals and the intra-class recognition of quadrature amplitude modulation (QAM) signals, as well as the related interference direction finding algorithm: 1. Aiming at the problems of multi-carrier and single-carrier signals, A method of orthogonal frequency division multiplexing (OFDM) and single carrier signal recognition for Kurtosis coefficients of power spectrum based on bandwidth and power normalization is proposed. The robustness and recognition performance of the characteristic parameters are verified by simulation. The correct recognition rate of SNR=0dB and single carrier can be more than 95%. In view of the problem that timing error and frequency offset will cause the reduction of QAM signal recognition rate, A scheme to improve the recognition performance is proposed. Firstly, the received MQAM signal is processed with OM timing synchronization and nonlinear differential processing. Finally, the amplitude logarithmic likelihood recognition of the signal is carried out. The simulation results show that the proposed scheme has a strong adaptability to timing error and frequency offset, when SNR? The average recognition rate of 12d BU QAM signal can reach 98.3. aiming at the problems of low precision and poor real time in the traditional correlation interference direction finding algorithm, the interpolation fitting method is proposed to improve the direction finding accuracy. In addition, the structure of correlation direction finding is improved, the space angle is introduced, and one dimensional information is used to replace the two dimensional spatial information. In terms of calculation amount, the calculation amount of 73% is reduced. Therefore, the real-time performance of the algorithm is improved. 4. Based on the FPGA DSP hardware platform, the working mode and sample database storage of the dual-channel correlation interference direction finding processing module are presented. At last, the time and accuracy of direction finding at single frequency point are analyzed, and the results show that both of them reach the target of direction finding.
【學位授予單位】：電子科技大學
【學位級別】：碩士
【學位授予年份】：2014
【分類號】：TN98

【參考文獻】

相關(guān)碩士學位論文 前1條

1 劉思沉;短波寬帶測向算法研究及其實現(xiàn)[D];西安電子科技大學;2010年

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本文編號：1603556