具多信號產生與判別特性之渦輪碼

多信號產生技術的原理，就是將相同的使用者資料，利用某種方法產生Q>1種不同的表示信號。傳送端根據不同的傳送需求從中選出一個信號來傳送。一般而言，在傳送端傳送資料時，附帶消息必須隨著被傳送的資料一同被傳出。如此，接收端才能根據所收到的附帶消息，來復原被傳送資料。但這額外傳送的附帶資料將會造成一些資料量的損失，或者是在接收端時解碼時，錯誤的附帶資料將會造成增加系統錯誤率。本篇論文中，我們提出兩種具多信號產生特性之渦輪碼。第一類是在渦輪碼的系統下利用不同的交錯器或是隨機序列來產生多個信號。這一類系統的特點是就是傳送端不需要傳送額外的附帶資料，在接收端我們利用渦輪解碼時的判別能力來挑選可能被傳送的資料。另一類多信號產生的技術是採用咬合碼的觀念，這想法可以適用於任何有關於咬合碼的編碼中。例如：咬合式迴旋碼，咬合式渦輪碼。利用咬合碼的限制條件，在不需要明確附帶資料的情況下，接收端一樣可以判別出正確的訊號。為了驗證所提出的多信號產生與判別的技術，我們提供了三種渦輪碼系統分別是用來降低高峰均值比、信號衰減與傳送功率的應用。在這些實例中我們發現，所提出的這些多信號產生技術，能比現有的技術提供更好的系統效能或是減少的系統資料量的損失。最後，我們所提出的信號產生與判別的觀念不只能應用於渦輪碼上，也適用於其他的編碼系統中。

關鍵字

渦輪碼；多信號產生技術；正交分頻多工系統；峰均值比；咬合碼；選擇式映射

並列摘要

The concept of multiple-candidate is implemented by choosing a candidate from Q>1 candidates, that carry the same user data, for actual transmission based on an appropriate criterion. In general, side information (SI) is included in the transmitted symbols such that receiver can recovery the SI and associated candidate. The extra SI would induce rate loss and incorrect SI would degrade the system performance. In this thesis, we propose two multiple-candidate generation methods for turbo coding. First, the generation of multiple-candidate without SI by using various interleaver or random sequence in turbo coded system is proposed. Using the powerful discriminating capacity of turbo decoding, the SI can be removed and waived into the turbo codeword. Another multiple-candidate generation with inexplicit SI by employing the tail-biting bits of tail-biting (recursive) convolutional codes or turbo codes is also proposed. Using the tail-biting constraint, the decoding could select the correct candidate sent from transmitter without explicit SI. Three turbo coded systems, which respective aim to reduce the peak to average power ration (PAPR), clipping noise, and average transmit power, are constructed to demonstrate the advantage of the proposed multiple-candidate methods. Compared to the conventional methods, these proposed schemes can eliminate the serious degradation in bit-error performance which results from the incorrect recovery of SI at receiver and avoid/alleviate the rate loss. Finally, not only the turbo coding, the proposed multiple-candidate generations could also apply to other coded systems.

並列關鍵字

Turbo codes ； multiple-candidate ； Orthogonal frequency-division multiplexing (OFDM) ； peak-to-average power ratio (PAPR) ； tail-biting ； selective-mapping (SLM) ； selective-clipping ； shaping.

參考文獻

R.~Bauml, R.~Fischer, and J.~Huber, ``Reducing the peak-to-average power ratio of multicarrier modulation by selected mapping,' Electronics Letters,vol.~32, pp.~2056--2057, Oct. 1996.

Z.~Li and B.~V. K.~V. Kumar, ``Low-density parity-check codes with run length limited (RLL) constraints,' IEEE Trans. Magn., vol.42, pp.~344--349, Feb. 2006.

X.~Lei, Y.~Tang, S.~Li, and Y.~T. Li, ``A minimum clipping power loss scheme for mitigating the clipping noise in OFDM,' GlobalTelecommnuications Conference, vol.~1, pp.~6--9, Dec. 2003.

H.~Ochiai and H.~Imai, ``Performance of the deliberate clipping with adaptive symbol selection for strictly band-limited OFDM systems,' IEEE J. Select. Areas Commun., vol.~18, pp.~2270--2277, Nov. 2000.

M.~Breiling, S.~H. Muller-Weinfurtner, and J.~B. Huber, ``SLM peak-powerreduction without explicit side information,' IEEE Commun. Lett.,vol.~5, pp.~239--241, June 2001.

國際替代計量

具多信號產生與判別特性之渦輪碼

全文下載

主題瀏覽