在干擾環境下應用低密度奇偶校驗碼之影像之傳輸技術研究

Image transmission for Low-Density Parity Check coded system under PBNJ

楊清皓(Ching-Hao Yang)

指導教授 ： 鄭立德

中原大學/電機資訊學院/通訊工程碩士學位學程/碩士(2013年)

https://doi.org/10.6840/cycu201300910

摘要

摘要
前人藉由整合影像修復技術和錯誤更正碼的影像傳輸系統將系統抵抗干擾的能力提升。再者，將整合影像修復技術和錯誤更正碼的影像傳輸系統進一步加入遞迴式解碼的技術來改善系統效能。整合遞迴式解碼的錯誤更正碼架構是將解碼前和影像處理完的碼字做比較，其差值來判斷是否為擦失掉的依據，擦失完成後將剩餘的碼字送回解碼器做errors-and-erasures decoding。
近年來，因為低密度奇偶校驗碼能依據系統的特性調整碼字長度以及具有較佳的錯誤更正能力使其變為熱門的研究項目。我們以前人的系統為基礎，提出一影像傳輸的系統，將里德-所羅門碼取代為低密度奇偶校驗碼並依據低密度奇偶校驗碼的特性提出兩種影像修復的方法。除此之外，我們也結合通道的資訊與影像修復完的資訊提出一遞迴解碼的架構。模擬結果將計算影像的Peak signal to noise ratio (PSNR) 值來比較系統抗干擾的能力。

關鍵字

部分頻帶干擾 ； 影像修復 ； 遞迴解碼 ； 低密度奇偶校驗碼

並列摘要

ABSTRACT
In recent years, the research about Reed-Solomon (RS) codes for slow frequency-hopping systems have been extensively studied. Previous studies has combined the error-correction coding and image restoration technique to increase the anti-jam (AJ) capability in image transmission system. Moreover, the combination of iterative decoding technique and image restoration can improve the performance of original system.
Low-Density Parity Check codes (LDPC) become popular because of its flexibility in codeword length and with better performance than other channel codes. In this thesis ,we propose a system which use LDPC for image communication under partial band noise jamming (PBNJ). Moreover, we also propose a iterative decoding scheme which combined the information after image process and information in channel to do iterative decoding.
To compare the image performances in jamming environment, we evaluate the error probabilities and the peak signal to noise ratio(PSNR) values of transmitted images.

並列關鍵字

Image restoration ； Iterative decoding ； Low-Density Parity Check Codes ； Partial-Band Noise Jamming

參考文獻

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[4] Li-Der Jeng and Chien-Hung Su, “Image restoration for Reed-Solomon coded SFH/MFSK System With Partial-Band Noise jamming,” Intelligent Signal Processing and Communication Systems, 2009. ISPACS 2009.

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