MQAM調制方式的頻域均衡系統(tǒng)研究

摘  要

單載波頻域均衡（SC/FDE）技術，不僅可以有效對抗信道的頻率選擇性衰落，實現(xiàn)高速率、大容量的通信傳輸，而且能夠避免單載波時域均衡（SC/TDE）復雜度大和正交頻分復用(OFDM)技術峰均功率比高的不足，是寬帶無線接入系統(tǒng)物理層的重要組成技術。近五年來，關于單載波頻域均衡的討論日漸增多，并且已經(jīng)被納入IEEE802.16(WiMAX)標準中。然而對SC/FDE的研究大多還只是集中在理論仿真階段，很少有實際的系統(tǒng)實現(xiàn)。
本文介紹了采用MQAM調制方式的單載波頻域均衡(SC/FDE)技術。MQAM是一種節(jié)省頻帶資源的數(shù)字調制方式，廣泛應用于有線數(shù)字視頻廣播和寬帶接入等通信系統(tǒng)中， 本文重點研究頻域均衡的基本思想、均衡器的結構、LS均衡算法和一種采用16QAM調制方式的SC/FDE系統(tǒng)的Matlab仿真調試。
關鍵詞：單載波調制； 頻域均衡； SC/FDE； MQAM； LS算法。
 
ABSTRACT

   SC/FDE (Single Carrier-Frequency Domain Equalization) allows an advantage of high-speed data transmission in frequency-selective fading channel. It avoids the complexity of SC/TDE (Single Carrier-Time Domain Equalization) and the high PAPR (Peak Average Power Ratio) of OFDM (Orthogonal Frequency Division Multiplexing) as well. It becomes one of the most important components of the wideband wireless access technique. In recent years, there is more and more discussion about SC/FDE, including been brought into the IEEE802.16 (WIMAX) protocol .However, most of research work still focuses on theories of parts not whole system ,and less implementation in real hardware platform .
This paper introduces the technology of SC/FDE with the modulation method of 16QAM. MQAM is a digital modulation which saves bandwidth resources. It is widely used in cable digital video broadcasting and broadband access and other communications systems. This paper focuses on the basic idea of frequency-domain equalization and the structure of equalizer. The LS equalization algorithm is also given, as well as the simulation and debugging of SC/FDE with 16QAM modulation on Matlab platform.
Keyword: Single-Carrier modulation; Frequency-Domain Equalization; SC/FDE; MQAM; LS algorithm .
目    錄

第一章  緒  論 1
1.1單載波頻域均衡 (SC/FDE) 系統(tǒng)概述 1
1.1.1正交頻分復用(OFDM)系統(tǒng) 1
1.1.2 SC/FDE系統(tǒng)的概述 2
1.1.3 OFDM和SC/FDE系統(tǒng)的比較和共存 4
1.2 SC/FDE技術應用及前景 6
1.3 研究的目的及意義 6
第二章  MQAM調制與解調的相關理論 7
2.1 QAM調制與解調的原理 7
2.2 多電平QAM調制與解調原理 8
第三章  均衡原理 10
3.1 均衡的概念和意義 10
3.2 均衡的分類 10
3.2.1 時域均衡 10
3.2.2 頻域均衡 12
3.3 頻域均衡的基本思想和算法 13
3.3.1 頻域均衡的基本思想 13
3.3.2 最小二乘算法 14
第四章  信道估計 15
4.1信道的分類 15
4.2 寬帶無線移動信道 15
4.2.1無線信道分析 15
4.2.2平坦衰落信道 16
4.3 SC/FDE系統(tǒng)中的信道估計技術 17
第五章  SC/FDE系統(tǒng)的仿真 19
5.1 仿真MATLAB的介紹 19
5.1.1 MATLAB 19
5.1.2 MATLAB工具箱 19
5.2 計算機仿真 20
5.2.1 高斯信道中SC/FDE系統(tǒng)的仿真 20
5.2.2 運行結果分析 33
結束語 35
致謝 36
參考文獻 37
附錄 38