以具有區段特性之錯誤更正碼降低峰均比之設計

Abstract

在正交分頻多工系統中，峰均比是其中一個廣為人知的問題。在這篇碩士論文中，我們提出幾個使用多訊號處理的方法以降低峰均比同時不會犧牲過多的位元錯誤率。特別提出一種Q-段二元錯誤更正碼，其碼句被分為Q段而將任一段的位元反轉的結果會是另一個碼句。我們用極化碼以及低密度奇偶檢查碼來設計Q-段二元錯誤更正碼，其中我們還提出了一種可以用來產生具有區段特性的低密度奇偶檢查碼之PEG演算法。而另一種錯誤更正碼，即非二元低密度奇偶檢查碼亦可被用於降低峰均比，這部份我們結合了前人的方法，包含位元翻轉以及內嵌邊訊息的選擇性映射法。模擬結果顯示我們的設計可以很有效的結合峰均比的降低以及錯誤更正碼的效果。

In the orthogonal frequency division multiplexing (OFDM) communication systems, one of the challenging issues is high peak-to-average power ratio (PAPR). In this thesis, we propose several multiple signaling techniques to reduce PAPR. In particular, we propose a Q-section binary error-correcting code, of which each codeword is divided into Q-sections and the reverse of code bits in any section results in another codeword. We propose Q-section code constructions for polar codes and low-density parity-check (LDPC) codes. Besides, we proposed a modified PEG algorithm to construct the desired LDPC codes with Q-section property. We also introduce non-binary LDPC codes for PAPR reduction, which is integrated with others previous work, includes: bit-flipping method and side information embedded selective mapping. The simulation results show that our design can appropriately integrate PAPR reduction and error correcting coding.