正交分頻多工系統中高效次通道降峰值法

Abstract

在本篇論文中，我們提出一低複雜度且不需額外訊息降低功率峰均比的方法。此方法是利用選出一些被擴充的子通道分別乘上旋轉因子產生額外的自由度來降底功率峰均比。雖然此方法會增加傳輸所需能量，我們仍可以在額外消耗的能量與錯誤率之間來權衡。此外，經過分析後可發現本方法所產生的複雜度相當低，並且由實驗可知，本方法可以有效率地降低功率峰均比。

In this paper, we propose a low-cost PAPR (peak to average power ratio) reduction method called SPR (subchannel peak reduction) method that requires no side information for OFDM (Orthogonal Frequency Di- vision Multiplexing) systems. We select a small number of subchannels, called PR (peak reduction) subchannels, to reduce peak value of the trans- mitter output. The constellation on the PR subchannels are extended to twice the size. The enlarged constellation oRers freedom in bit-to-symbol mapping, which will be exploited for peak reduction. Although the trans- mitted power increases due to constellation extension, a nice tradeoR be- tween probability of error and transmitted power can be achieved. The simulation results show that the proposed method can achieve eRective peak reduction at a very low complexity.