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Performance studying on software radio architecture
|關鍵字:||software radio;軟體無線電;mobile communication;行動通訊||出版社:||電機工程學系||摘要:||
近年來，起源於軍事用途的軟體無線電，由於它優越的適應性(flexibility)，加上軟體無線電核心積體電路元件如ADC (analog-to-digital converter) 和DSP (digital signal processors) 發展快速，使得軟體無線電逐漸受到大家重視，逐步應用到商業行動通訊系統。
在本論文中介紹使用次採樣法(band-pass sampling)在中頻和射頻端直接採樣的軟體無線電架構，第二章分析不同A-D轉換器的量化雜訊和SCJ(sampling clock jitter)雜訊對系統性能的影響，並使用Standard Gaussian approximation (SGA)方法分析系統於多路徑衰減通道環境的性能，在分析系統性能時，在接收端採用傳統接收機、Equal Gain Combining RAKE及Maximal Ratio Combining RAKE receiver三種類型的接收機架構。
第三章使用statistic correlation distribution convolution(SCDC) 方法分析系統於多路徑衰減通道環境的性能。我們也將比較wavelet packet based CDMA code與Gold code性能的差異。第四章介紹軟體無線電應用於基地台陣列天線的性能表現，比較在多路徑衰減通道中使用MVDR-RAKE陣列天線和單一天線系統的性能；由於軟體無線電將大部分的工作置於DSP，因而系統可以不用改變硬體，用軟體升級所需的演算法。第五章探討兩種不同的分集架構：(1)二維時間-空間分集，(2)二維空間-時間分集架構；第六章為結論與建議。
The software radio is emerging from military applications. Because of recent advances in high-speed digital signal processors (DSP's) and analog-to-digital converter (ADC's), the commercial implementation of software radio has become viable. In this thesis, the IF signal is digitized using bandpass sampling, and all of the subsequent processing is implemented in software. The quantization noise and sampling clock jitter noise of the ADC in the receiver are taken into account in chapter 2. In chapters 2, a numerical method, the standard Gaussian approximation (SGA) algorithm, is developed explicitly to study bit error rate of CDMA systems under varying multipath fading environment. Two different types of RAKE receiver structures, equal gain combining RAKE and maximum ratio combining RAKE, are also considered for CDMA systems to mitigate multipath fading effects of mobile channels. In chapter 3, a numerical method, the statistic correlation distribution convolution (SCDC) algorithm, is developed explicitly to study bit error rate of wavelet-packet based CDMA systems under varying multipath fading environment. The performance of wavelet-packet based CDMA system is compared with that of traditional CDMA systems using Gold codes. Chapter 4 has presented the software radio architecture with smart antennas. We compare the BER performance of minimum variance-distortionless-response RAKE (MVDR-RAKE) and omnidirectional antenna RAKE scheme. The advantages of software radio implementation of wireless communication systems include flexibility for adaptive beamforming with novel algorithms. In chapter 5, the following configurations are suggested: (1) two dimension space-time diversity, (2) two dimension time-space diversity. Finally, the conclusion and remaining work are given in chapter 6.
|Appears in Collections:||電機工程學系所|
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