多速率資料傳輸的保護與時間訊號同步

Data Protection and Acquisition for Multirate Transmissions

傅智銘(Chih-Ming Fu)

指導教授 ： 黃仲陵 ； 黃文良

國立清華大學/電機資訊學院/電機工程學系/博士(2006年)

https://doi.org/10.6843/NTHU.2006.00225

摘要

這篇論文主要討論在訊號層次與封包層次的多速率傳輸之錯誤防止。在訊號層次上，我們提出了一個以次空間為基礎的方式來獲取多速率小波調變的時間同步訊號，模擬的實驗結果顯示，我們可以順利的獲取訊號區間的開頭資訊，並且只要需要少量的後續追蹤的變異量作為代價。我們還提出了碎型調變資料同步獲取方式，我們利用最大概率的技術來建構我們的同步獲取函式，並且利用循序的找尋方式來得到碎型調變的開始位置。

在封包層次的多速率傳輸技術中，我們提出了分析式的失真函數作為訊號與通道編碼的演算法基礎。我們的方法將視訊壓縮與包裝傳輸分成兩個獨立的工作區塊，這樣一來我們就可將壓縮與封包傳輸分開來，並且適用在不同的多速率壓縮技術上。為了證實我們的效能，我們使用了兩個狀態的馬可夫模型去描述具有連續錯誤特性的通道，並且使用錯誤更正碼來保護資料。此外我們還提出一個全新的架構可以將接收端的後處理整合在失真函數中，並且作最佳化的錯誤保護分配，模擬的實驗結果顯示，我們的方法比之前的方法效能還要好很多。

我們建構出在訊號層次與封包層次的多速率資料傳輸的方法，並且找的多速率傳輸所會與到的問題並且提出解決方案，同時更提出了一個結合接收端後處理的整合式傳輸保護機制達到極佳的效能。

關鍵字

小波 ； 碎型 ； 調變 ； 多速率 ； 傳輸 ； 錯誤控制碼 ； 錯誤隱藏 ； 獲取

並列摘要

This thesis will discuss the error-resilient multirate transmissions on the signal level and the packet level. It proposes a subspace-based approach for acquiring the timing of wavelet-based multirate transmission systems. This shows that our approach can correctly acquire the initial timing of a symbol from anywhere within a symbol-time interval at a cost of increasing jitter variance. Then, we propose a frame timing acquisition algorithm for fractal modulation. Our algorithm exclusively uses the data redundancy inherent in fractal modulation to locate the start time of all the sub-bands (start-of-frame). The acquisition functions are derived using the maximum-likelihood method and the start-of-frame that maximizes the function attained by a serial search algorithm.

For packet level multirate transmissions, we propose an analytical Rate-Distortion optimized joint source and channel coding algorithm for error-resilient scalable encoded video for lossy transmission. Our method separates video coding and packetization into diRerent tiers which can be easily incorporated into any coding structure that generates a set of independent compressed bit-streams. To demonstrate the performance, we use the 2-state Markov model to describe the burst loss channel and Reed-Solomon codes as forward error correction codes.

We also propose a new framework in which the encoder estimates the effects of post-processing concealment and includes those effects in the rate-distortion analysis. Based on our framework, we develop optimal forward error control assignment

並列關鍵字

wavelet ； fractal ； modulation ； multirate ； transmission ； FEC ； error-concealment ； acquisition

參考文獻

[1] M. Luise, M. Marselli, and R. Reggiannini, "Clock synchronization for wavelet-based multirate transmissions," IEEE Trans. on Commun., vol. 48, pp. 1047-1054, June 2000.

[2] J. Kim, R. M. Mersereau, and Y. Altunbasak, "A multiple-substream unequal error-protection and error-concealment algorithm for spiht-coded video bitstreams," IEEE Trans. Image Process., vol. 13, pp. 1547-1553, Dec. 2004.

[3] G. Wornell and A. V. Oppenheim, "Wavelet based representations for a class of self similar signals with applications to fractal modulation," IEEE Trans. on Inform. Theory, vol. 38, pp. 758-800, March 1992.

[4] G. Wornell, "Emerging applications of multirate signal processing and wavelets in digital communications," Proc. IEEE, vol. 84, pp. 586-603, April 1996.

[5] L. Atzori, D. D. Giusto, and M. Murroni, "Performance analysis of fractal modulation transmission over fast-fading wireless channels," IEEE Trans. on Broadcasting, vol. 48, pp. 103-110, June 2002.