本文選題：交叉極化干擾抵消器 + 載波同步�。� 參考：《電子科技大學》2014年碩士論文

【摘要】：隨著無線通信業(yè)務的需求日益增加,無線移動通信技術得到迅猛的發(fā)展,但是卻始終面臨著頻譜短缺這一嚴重問題。無線通信系統(tǒng)中,提高頻譜利用率是研究重點之一。提高頻譜利用率,除了可以采用QAM調制技術,也可以采用極化波復用技術。采用極化波復用技術時,涉及到在信道中造成的交叉干擾,抵消交叉干擾會用到交叉極化干擾抵消器,本文討論了交叉極化干擾抵消器的結構以及相關算法;采用QAM調制技術時,解調一般采用相干解調技方式,而載波同步環(huán)路是相干解調不可或缺的環(huán)路之一。首先,本文介紹了交叉極化干擾抵消器的結構與算法。本文主要介紹了三種算法,包括LMS算法、DD-LMS算法和CMA算法�；贒D-LMS和CMA算法各自的優(yōu)點,討論了DD-LMS和CMA的切換算法。根據(jù)算法的數(shù)學推導,用Simulink分別對DD-LMS、CMA和切換算法進行建模,在信道中設定一定的交叉極化干擾,分析比較算法的性能。仿真后,用Verilog實現(xiàn)DD-LMS算法的交叉干擾抵消器,并在FPGA板上進行了功能仿真和板級仿真,調試結果正確。其次,介紹了載波同步環(huán)路的原理以及算法。本文主要討論了載波同步環(huán)路的DD算法、極性判決法及二者的切換算法。根據(jù)算法的數(shù)學推導,用Simulink分別對DD算法、極性判決法和切換算法進行建模,在信道中設定一定的頻偏,分析比較算法的性能。仿真結果說明,采用DD算法的載波同步環(huán)路收斂速度慢,但收斂后,相位誤差抖動小,捕獲的頻偏穩(wěn)定;采用極性判決法的載波同步環(huán)路收斂速度快,但是收斂后相位誤差抖動大,捕獲的頻偏抖動也大;而切換算法具備二者的優(yōu)點。之后,用Verilog實現(xiàn)切換算法的載波同步環(huán)路,對載波同步環(huán)路單個模塊在FPGA板上進行功能仿真和板級仿真,證明了采用切換算法的載波同步環(huán)路可以達到很好的糾正頻偏的效果。并對載波同步環(huán)路進行系統(tǒng)聯(lián)合調試,調試結果正確。
[Abstract]:With the increasing demand of wireless communication services, the wireless mobile communication technology has been developing rapidly, but it is always faced with the serious problem of spectrum shortage. In wireless communication system, improving spectrum efficiency is one of the key research points. In order to improve spectral efficiency, not only QAM modulation technology can be used, but also polarization multiplexing technology can be used. When using polarization multiplexing technology, the cross-interference caused by the channel is involved, and the cross-polarization interference canceller is used to cancel the cross-polarization interference. In this paper, the structure of the cross-polarization interference canceller and the related algorithms are discussed. When QAM modulation technology is adopted, coherent demodulation is generally adopted, and carrier synchronization loop is one of the indispensable loops for coherent demodulation. Firstly, the structure and algorithm of cross polarization interference canceller are introduced. This paper mainly introduces three algorithms, including LMS algorithm, DD-LMS algorithm and CMA algorithm. Based on the advantages of DD-LMS and CMA, the switching algorithms of DD-LMS and CMA are discussed. According to the mathematical derivation of the algorithm, the DD-LMSCMA and the handoff algorithm are modeled by Simulink, and the cross-polarization interference is set up in the channel, and the performance of the algorithm is analyzed and compared. After simulation, the cross interference canceller of DD-LMS algorithm is realized by Verilog, and the functional simulation and board level simulation are carried out on the FPGA board, and the debugging results are correct. Secondly, the principle and algorithm of carrier synchronization loop are introduced. This paper mainly discusses DD algorithm, polarity decision method and switching algorithm of carrier synchronous loop. According to the mathematical derivation of the algorithm, the DD algorithm, the polarity decision method and the switching algorithm are modeled by Simulink, and a certain frequency offset is set up in the channel to analyze and compare the performance of the algorithm. The simulation results show that the convergence speed of the carrier synchronization loop using DD algorithm is slow, but after convergence, the phase error jitter is small, and the frequency offset of the acquisition is stable. However, the phase error jitter after convergence is large, and the frequency offset jitter captured is also large, and the switching algorithm has the advantages of both. After that, the carrier synchronization loop of the switching algorithm is implemented by Verilog, and the single module of the carrier synchronization loop is simulated on the FPGA board. It is proved that the carrier synchronization loop with the switching algorithm can correct the frequency offset very well. And carry on the system joint debugging to the carrier synchronous loop, the debugging result is correct.
【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】：TN92
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本文編號：2091938