請用此 Handle URI 來引用此文件:
http://tdr.lib.ntu.edu.tw/jspui/handle/123456789/15503
標題: | 結合頻譜預等化與降低峰均功率比之頻譜預編碼正交分頻多工系統 Spectrally Precoded OFDM with Pre-equalization and Reduced PAPR |
作者: | Po-Hsien Wang 王博賢 |
指導教授: | 鐘嘉德(Char-Dir Chung) |
關鍵字: | 正交分頻多工,頻譜緊密度,道道容量,預等化,峰均功率比, Orthogonal frequency-division multiplexing,spectrum compactness,channel capacity,channel pre-equalization,peak to-average power ratio, |
出版年 : | 2020 |
學位: | 碩士 |
摘要: | 在固定環境的傳輸系統中,若傳送端取得通道資訊時,結合了正交分頻多工(OFDM)的頻譜預編碼(spectral precoding)以提供非常緊密的訊號頻譜和降低峰均功率比(PAPR),並使用通道資訊進行預等化,使其分別達到最大化的通道容量、線性最小化均方誤差及最小化近似位元錯誤率。首先針對發送的N個次載波的OFDM訊號設計通用預編碼器,採用預編碼率1-2I/N,將N-2I個符元加入2I個冗餘(redundancy),以提供非常小的頻譜旁波,衰減的漸進速度為 f^(-2I-2),其中f是以Hz為單位的頻率,從而實現高頻譜緊密度;再結合通道資訊,在固定平均傳輸功率下設計頻譜預等化器,並加入了降低峰均功率比的功能。而在接收端,設計了線性最小均方誤差頻域等化器來進行錯誤率的模擬。本篇所提出的預等化和頻譜預編碼正交分頻多工(PSP-OFDM)系統提供非常接近預等化OFDM的通道容量,同時能保證頻譜的緊密度,進一步提供比頻譜預編碼、頻譜預等化或無預編碼的系統更高的頻譜效率。 For fixed frequency-selective dispersive channels. When the channel state information is known at transmitter, besides spectral precoding for rectangularly-pulsed orthogonal frequency-division multiplexing (OFDM) using cyclic prefix is studied to provide extremely compact signal spectrum and reduced peak-to-average power ratio (PAPR), the channel information is used to pre-equalize the signal to achieve maximum capacity (MC), linear minimum mean square error (LMMSE), and approximate minimum bit error rate (AMBER), respectively. With a precoding rate 1-2I/N and thus introducing 2I degrees of redundancy, a general spectral precoder is first developed for N-subcarrier OFDM signal to provide extremely small spectral sidelobes decaying asymptotically as f^(-2I-2), with f being the frequency in hertz. Incorporating the channel information, the spectral pre-equalizer is then designed for the fixed average transmitting power, and combine the function of reducing PAPR. For the error rate simulation, a linear minimum mean-square-error frequency domain equalizer is designed for the corresponding OFDM receiver. The proposed pre-equalized and spectrally precoded (PSP) OFDM system is shown to provide channel capacity which is very close to pre-equalized OFDM. When a small out-of-band power proportion is required to guarantee compact signal spectrum, the proposed PSP-OFDM system can further provide much higher spectral compactness than pre-equalized OFDM, spectrally precoded OFDM, and nonprecoded OFDM, all conveying the same data rate. |
URI: | http://tdr.lib.ntu.edu.tw/jspui/handle/123456789/15503 |
DOI: | 10.6342/NTU202001494 |
全文授權: | 未授權 |
顯示於系所單位: | 電信工程學研究所 |
文件中的檔案:
檔案 | 大小 | 格式 | |
---|---|---|---|
U0001-1407202009035200.pdf 目前未授權公開取用 | 3.54 MB | Adobe PDF |
系統中的文件,除了特別指名其著作權條款之外,均受到著作權保護,並且保留所有的權利。