正交分頻多工系統之峰值對平均功率比降低方法

Abstract

在高速資料傳輸的需求下, OFDM 是一個相當可行的技術. 它可以有效地處理多路徑傳輸引起的符際干擾問題. OFDM的主要缺點之一是其峰值對平均功率的比值(PAPR)較高. 這個現象會使得傳送端與接收端的非線性造成整體系統效能的降低. 在這篇論文裡, 我們會討論功率峰值的問題.在文獻中有許多減低PAPR的方法被提出來, 我們對這些方法作一個整理. 同時我們也研究解決PAPR偏高的方式. 我們建議使用 “ 訊號變形伴隨被交錯過之錯誤控制編碼 “ 來克服這個問題. 這個方法也可以和多訊號表示法結合以得到更進一步的改善.

Orthogonal Frequency Division Multiplexing (OFDM) is a very promising technique for high-speed data transmission. It can effectively take care of the inter-symbol interference induced by multipath propagation over radio channels. One of the major drawbacks of OFDM is the high peak-to-average power ratio (PAPR). Thus, the nonlinearity between transmitter modulator and receiver demodulator will degrade the overall system performance because of the large dynamic range of the OFDM signal. In this thesis, the peak power problem in OFDM is discussed. PAPR reduction techniques in the literature are reviewed. Also, we investigate several schemes to take care of this issue. An approach termed “deliberate signal distortion with interleaved error-control coding” can be used to deal with this problem. This approach also can be combined with multiple signal representation techniques to achieve more improvement in PAPR reduction.