Acta Photonica Sinica, Volume. 45, Issue 4, 406003(2016)
Performance of Non-binary Low Density Parity Check Codes in 16QAM Optical Transmission Systems
Taken 16 Quadrature Amplitude Modulation (16QAM) as an example, the performance of three kinds of LDPC codes over Galois fields (GF(2m)) for m=1,2,4 in 16QAM systems was analyzed. The simulation results show that 4-ary LDPC code, rather than 16-ary LDPC, shows significant advantages in both error correction performance and decoding efficiency. Then in order to further improve the performance of NB-LDPC codes in high-order modulation systems, the watermark symbols are introducted into 4-ary LDPC codes in 16QAM systems. Compared with traditional non-binary LDPC decoding, the average iteration number of watermark scheme presents a quite obvious decrease, it means that the decoding efficiency can be greatly improved by using watermark scheme. Moreover a further Net Code Gain (NCG) improvement of about 0.1 dB can be attained when bit error ratio BER=10-5.
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WANG Li-ming, QIAO Yao-jun, ZHANG Wen-bo. Performance of Non-binary Low Density Parity Check Codes in 16QAM Optical Transmission Systems[J]. Acta Photonica Sinica, 2016, 45(4): 406003
Received: Oct. 28, 2015
Accepted: --
Published Online: May. 11, 2016
The Author Email: Li-ming WANG (wanglm2009jlu@163.com)