在正交分頻多工系統中以特意位元翻轉與錯誤更正碼降低峰均比之研究

Deliberate Bit Flipping with Error-Correction for PAPR Reduction in OFDM Systems

劉顏慶(Yen-Ching Liu)

指導教授 ： 林茂昭

國立臺灣大學/電機資訊學院/電信工程學研究所/博士(2016年)

https://doi.org/10.6342/NTU201601446

摘要

在正交分頻多工系統中，位元翻轉技術可用來降低峰均比。
而錯誤更正編碼可用來減緩因位元翻轉技術所造成的位元錯誤率惡化。
我們提出一些設計去適當地整合特意位元翻轉技術跟非對稱錯誤保護的錯誤更正碼。
我們使用一種修改過的密度進化方法來尋找適合我們位元翻轉系統的編碼度分佈。
而另一種錯誤更正碼，即猛禽碼亦可被用來減輕因翻轉位元所造成的位元錯誤率惡化。
模擬結果顯示出在很多狀況當中，我們所提出的設計可以有效的降低峰均比而且伴隨著非常微弱的位元錯誤率惡化。

關鍵字

正交分頻多工系統 ； 均峰值 ； 位元翻轉 ； 低密度奇偶檢查碼 ； 非對稱的錯誤保護 ； 密度進化 ； 猛禽碼

並列摘要

In the orthogonal frequency division multiplexing (OFDM) communications, bit flipping can be used for the reduction of peak-to-average-power ratio (PAPR).
Error-correction coding can be used to relieve the degradation of bit-error rates (BER) resultant from the bit-flipping.
We propose designs which appropriately integrate deliberate bit flipping and error-correcting codes with unequal error protection.
A modified density evolution method is used for obtaining appropriate code degree distributions to our bit-flipping system.
Another error-correcting codes, i.e. Raptor code also can be adopted to mitigate the BER degradation causing of the flipped bits.
Simulation results show that our proposed designs can obtain effective PAPR reduction with very minor BER degradation in many cases.

並列關鍵字

Orthogonal frequency division multiplexing (OFDM) ； peak-to-average power ratio (PAPR) ； bit-flipping ； low-density parity-check (LDPC) codes ； unequal error protection (UEP) ； density evolution ； Raptor code

參考文獻

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