Interleaving RS2 Error Correcting Code And Its Application To The Transmission Of Medical Signals

• Main Author: 林學毅
• Other Authors: 繆紹綱
• Format: Others
• Language: zh-TW
• Published: 1997
• Online Access: http://ndltd.ncl.edu.tw/handle/64067786212021469842

碩士 === 中原大學 === 電子工程學系 === 85 === 　　In the area of channel coding, the linear block code is a very important subclass of coding theory. Among many linear block coding methods. the Reed-Solomon code or RS code has very high capability in error correction. If other coding techniques are used in conjuction with the RS code, the capability can be enhanced further for the application (e.g. medical signal transmission ) where ultra high data-protection is needed. 　　This study proposes a RS-RS or RS2 concatenated coding method to enhance the protecting capability of RS code code against random noise. By combining with the interleaving scheme, the RS2 code can also tolerate longer burst error length (BL)．The code is designed so that the data protected by the RS inner code and those by the outer code have as little intersection as possible in order to achieve excellent error correcting capability. 　　The random error probability can be reduced from 0.05 to 5.5*10-4 by using 55 groups of interleaving RS2(63,55,4) code. This is better than using RS (63,55,4) or RS(63,49,7) code because their error probabilities are reduced to 0.0187 and 1.7*10-3, respectively. For the burst error, the inner code of 55 groups of interleaving RS2(63,55,4) code can protect against BL=224. In addition, the outer code can protect against BL=220. On the other hand, 55 groups of the traditional interleaving RS(63,55,4) code can protect against BL=220 only. Therefore, the interleaving RS2 code can protect against a longer burst-error length than a traditional interleaving RS code. 　　Since the interleaving RS2 code has very high error correcting capability, it is useful in protecting the compressed biomedical signals. The experiment on some compressed images show that if the interleaving RS2 code is used to protect the signals, even for very the high noise case (p=0.02, P=0.1, h=0.1 in Gilbert noise model), the erroneous data can be partially corrected so that the peak signal to noise ratio is increased from 21.01 dB to 26.88dB. This result is better than 22.34dB obtained by using RS(63,49,7) code . As to the compressed ECG signals, when a burst error of BL=100 occurs, the percent root-mean-square difference is 11.29% if no error protection is provided. This value can be reduced to 5.72% as if no error occured by using the interleaving RS2 code.