Current Proceedings on Technology

Yazarlar: Cristian Prodaniuc, Bomin Li, Knud J. Larsen

Konular:-

Anahtar Kelimeler:Forward Error Correction,Rate-adaptive coding,Coding gain,Bit-Error Rate,Signal-to-Noise Ratio

Özet: A rate-adaptive coding scheme using two-layered variable rate forward error correction (FEC) for Optical Fiber Transmission Systems with fixed signal constellation and fixed symbol rate is proposed. The first level of coding uses serially concatenated Reed-Solomon (RS) codes with hard-decision decoding which provides a coding gain of up to 12.25 dB. For lower SNR transmissions, a second layer of coding is employed, using either an extended Hamming(8,4,4) code or a Reed-Muller(1,4) code together with soft-decision decoding, with 3-bit quantization. The extended Hamming(8,4,4) code extends the coding gain up to 15.75 dB, while the Reed-Muller(1,4) works up to 18 dB. All coding gains are calculated for an output BER of 10-15. The rate-adaptive algorithm counts the number of values in certain quantization intervals and uses this to estimate the standard deviation and SNR. Estimation error is less than 0.15 dB. The coding scheme proposed is able to handle SNR variations in the range from 10 down to 0 dB, providing information bit rates starting from 100 Gbit/s down to 14.33 Gbit/s when the theoretical transmission bit rate is assumed to be 114.095 Gbit/s

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