自適應(yīng)調(diào)制技術(shù)表示根據(jù)無線信道的條件來選擇應(yīng)用的調(diào)制方案。在現(xiàn)代,由于帶寬有限,自適應(yīng)調(diào)制方案在無線通信系統(tǒng)中得到了廣泛的使用。自適應(yīng)調(diào)制方案有效地利用了可用帶寬,來增加系統(tǒng)的吞吐量。它的主要目的是降低誤碼率,提高無線通信系統(tǒng)的吞吐量。在本文中,將自適應(yīng)調(diào)制方案應(yīng)用于3G UMTS/WCDMA無線通信技術(shù)中,通過無線信道的信噪比來調(diào)節(jié)調(diào)制模式,以實現(xiàn)降低誤碼率,提高吞吐量和提高信號服務(wù)質(zhì)量。自適應(yīng)調(diào)制可以應(yīng)用與一個廣大的覆蓋區(qū)域。與3GUMTS/WCDMA中的64-QAM的單調(diào)制方案相比,由于自適應(yīng)調(diào)制方案中吞吐量更高,無線信道衰落效應(yīng)和數(shù)據(jù)錯誤率帶來的影響大大降低了。同時,通話質(zhì)量將得到改善;即使用戶在遠離BTS的地方通話也不會在受到頻繁掉線的困擾。在自適應(yīng)調(diào)制方案中,我們應(yīng)用了不同調(diào)制方案(例如64-QAM,16-QAM,QPSK,BPSK),這使得我們能夠在每符號每秒傳輸大連的消息比特,從而獲得大的吞吐量或者更好的頻譜效率。自適應(yīng)調(diào)制的利用,使得無線系統(tǒng)能夠針對信道情況找到最佳數(shù)字調(diào)制方案。本文中分析了不同組合的數(shù)字調(diào)制方案的性能改善效果,本文中研究的是一種最佳的數(shù)字調(diào)制組合方案...

【文章頁數(shù)】：133 頁

【學(xué)位級別】：碩士

【文章目錄】：
摘要
ABSTRACT
CHAPTER 1. INTRODUCTION
    1.1 BACKGROUND OF THE ADAPTIVE MODULATION
    1.2 MOTIVATION
    1.3 PROBLEM STATEMENT
    1.4 OBJECTIVES
    1.5 INTRODUCTION OF THE ADAPTIVE MODULATION
    1.6 SIGNIFICANCE OF THE RESEARCH
    1.7 OVERVIEW OF THE THESIS
CHAPTER 2. BASIC PRINCIPLE OF MODULATION SCHEMES
    2.1 OVERVIEW
    2.2 MODULATION SCHEMES
        2.2.1 BPSK
        2.2.2 QPSK
        2.2.3 QAM
    2.3 ADAPTIVE MODULATION SCHEME
    2.4 SNR ESTIMATION
CHAPTER 3. METHODOLOGY
    3.1 OVERVIEW
    3.2 BPSK MODULATION
        3.2.1 Generation of BPSK Signal and Measuring of SNR
        3.2.2 BER vs SNR of BPSK
    3.3 QPSK MODULATION
        3.3.1 Generation of QPSK Signal and Measuring of SNR
        3.3.2 BER vs SNR of QPSK
    3.4 16-QAM MODULATION
        3.4.1 Generation of 16-QAM Signal and Measurement of SNR
        3.4.2 BER vs SNR of 16-QAM
    3.5 64-QAM MODULATION
        3.5.1 Generation of 64-QAM Signal and Measurement of SNR
        3.5.2 BER vs SNR of 64-QAM
    3.6 ADAPTIVE MODULATION SCHEMES
CHAPTER 4. ADAPTIVE MODULATION IN SIMULATED ENVIRONMENT
    4.1 OVERVIEW
    4.2 SINGLE BASE STATION IN SIMULATED ENVIRONMENT
    4.3 TWO BASE STATION IN SIMULATED ENVIRONMENT
    4.4 SIX BASE STATION IN SIMULATED ENVIRONMENT
CHAPTER 5. ADAPTIVE MODULATION IN REAL SITUATION
    5.1 FIRST REAL SITUATION HAVING NO MOTION OF MOBILE USER W.R.T B. S
    5.2 SECOND REAL SITUATION HAVING MOTION OF MOBILE USER W.R.T B. S
    5.3 ADAPTIVE MODULATION IN COMPLEX FADING ENVIRONMENT
CONCLUSIONS
REFERENCES
ACKNOWLEDGEMENT



本文編號：3811495