本文選題：FDD　切入點(diǎn)：數(shù)字基帶系統(tǒng)　出處：《電子科技大學(xué)》2014年碩士論文

【摘要】：隨著LTE標(biāo)準(zhǔn)的廣泛應(yīng)用,全球范圍內(nèi)已有多家通信廠商研制出了近百款可以同時(shí)支持FDD和TDD的終端。如此看來,FDD-TDD通信系統(tǒng)在未來將得到更大規(guī)模的應(yīng)用。本課題的目的是設(shè)計(jì)一個(gè)能同時(shí)支持FDD和TDD模式的高速通信系統(tǒng)。FDD模式采用高階(64/256)正交幅度(QAM)調(diào)制方式,TDD模式調(diào)制方式為QPSK。本文主要介紹了FDD模式下的數(shù)字基帶系統(tǒng)實(shí)現(xiàn)。系統(tǒng)設(shè)計(jì)的難點(diǎn)在于高階QAM信號數(shù)字信號處理算法的設(shè)計(jì)與FPGA實(shí)現(xiàn)。除此以外,FPGA還要與DSP、ADC/DAC進(jìn)行通信。本文在闡述算法功能和原理的基礎(chǔ)上,詳細(xì)說明各算法功能模塊的實(shí)現(xiàn)以及優(yōu)化方法,然后對適用于高階QAM的盲均衡算法做了深入而詳細(xì)的研究:考慮到高階QAM信號模值不恒定的特性,采用恒模算法(CMA)結(jié)合多模算法(DAMA)的CADAMA算法;針對相位偏移的問題,改進(jìn)為MCADAMA算法;為了獲得更快的收斂速度和更低的穩(wěn)態(tài)誤差,采用T/4的分?jǐn)?shù)間隔結(jié)構(gòu);并且使用預(yù)測判決反饋結(jié)構(gòu)保證均衡器在干擾嚴(yán)重的情況下仍能正常工作。對均衡器用SIMULINK進(jìn)行仿真,說明其相比其他均衡器在性能上的優(yōu)勢。在文章的最后,進(jìn)行系統(tǒng)測試以及分析,驗(yàn)證了系統(tǒng)的正確性。
[Abstract]:With the wide application of LTE standard, many telecom manufacturers have developed nearly 100 terminals that can support both FDD and TDD.So it seems that FDD-TDD communication system will be used on a larger scale in the future.The purpose of this paper is to design a high speed communication system. FDD mode can support both FDD and TDD mode.This paper mainly introduces the realization of digital baseband system in FDD mode.The difficulty of system design lies in the design of high-order QAM signal digital signal processing algorithm and FPGA implementation.In addition, FPGA communicates with the DSP ADC / DAC.On the basis of expounding the function and principle of the algorithm, this paper explains the realization and optimization method of each arithmetic function module in detail.Then, the blind equalization algorithm suitable for high order QAM is studied in detail: considering the unsteady mode value of high order QAM signal, the CADAMA algorithm of constant modulus algorithm (CMA) and multimode algorithm (MMA) is used to solve the problem of phase shift.The equalizer is simulated by SIMULINK, and its performance is proved to be superior to that of other equalizers.At the end of the article, the system is tested and analyzed to verify the correctness of the system.
【學(xué)位授予單位】：電子科技大學(xué)
【學(xué)位級別】：碩士
【學(xué)位授予年份】：2014
【分類號】：TN911.5

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本文編號：1704608