透過預先編碼的方法在移動微波存取全球互通上降低峰值對均值功率比之研究

The Research of Peak-To-Average Power Ratio Reduction In Mobile WiMAX System By using Precoding Method

黨中祥(Chung-Hsiang Tang)

指導教授 ： 許超雲

大同大學/電機資訊學院/通訊工程研究所/碩士(2012年)

摘要

近年來正交分頻多工技術已經被廣泛使用於現今各式無線通訊系統，例如WLAN，DVB和WiMAX等，由於正交分頻多工是一種多載波調變技術，擁有較高的資料傳輸速度與能有效克服頻率選擇性通道衰減 (Frequency selective fading channel)的特性，但此技術也有需要克服的缺點，其中有一項主要的缺點就是會產生較高的峰均值功率比(簡稱PAPR)。降低正交分頻多工系統中高PAPR的問題就可提升高功率放大器(簡稱HPA)的效能則系統位元錯誤率(簡稱BER)就會降低， 此外降低類比與數位轉換量化的誤差則就能降低設計上的複雜度與成本。
本篇論文我們是採用預先編碼(簡稱Precoding)的技術應用在移動式「微波存取全球互通」(簡稱Mobile WiMAX)系統中，其模擬結果無論在下行或上行皆比我們實驗室所提出利用離散傅立葉轉換矩陣來的有效。當我們增加零子載波的個數越多則你能更有效降低PAPR，但是當考慮導航(簡稱Pilot)子載波的加入後，其結果就沒有先前模擬結果來的顯著。

關鍵字

峰均值功率比 ； 微波存取全球互通 ； 峰均值功率比

並列摘要

In recent years, Orthogonal Frequency Division Multiplexing technology(OFDM) has been widely used in today's all kinds of wireless communication systems such as WLAN，DVB and WiMAX such as orthogonal frequency division multiplexing is a multi-carrier modulation techniques, with higher the characteristics of data transmission speed and can effectively overcome frequency selective fading channel, but this technology also need to overcome the shortcomings , which has a major drawback is to produce high peak to average power ratio (PAPR) . Reduction the problem of high PAPR for OFDM system can enhance the performance of high power amplifier (HPA) system and reduce the bit error rate (BER). In addition, this also reducing the analog and digital conversion quantization error is able to reduce the design complexity and cost .
This thesis we adopt precoding technique in the application of Mobile「Worldwide Interoperability for Microwave Access system」(Mobile WiMAX ) for the reduction of PRPA. The simulation results show that no matter in downstream or upstream, the effect of reduction of PAPR, are higher than that of using discrete Fourier transform(DFT) matrix. As we increase the number of zero sub-carrier that we adopt for precoding, the more you can more effectively reduce the PAPR. But when Pilot sub-carriers are taken together, the result becomes not so significant as that of previous simulation results .

並列關鍵字

WiMAX ； Peak-To-Avererage Power Ratio ； PAPR

參考文獻

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