Evaluation of large girth LDPC codes for PMD compensation by turbo equalization.
Large-girth quasi-cyclic LDPC codes have been experimentally evaluated for use in PMD compensation by turbo equalization for a 10 Gb/s NRZ optical transmission system, and observing one sample per bit. Net effective coding gain improvement for girth-10, rate 0.906 code of length 11936 over maximum a posteriori probability (MAP) detector for differential group delay of 125 ps is 6.25 dB at BER of 10(-6). Girth-10 LDPC code of rate 0.8 outperforms the girth-10 code of rate 0.906 by 2.75 dB, and provides the net effective coding gain improvement of 9 dB at the same BER. It is experimentally determined that girth-10 LDPC codes of length around 15000 approach channel capacity limit within 1.25 dB.
Minkov
Lyubomir L
LL
Department of Electrical and Computer Engineering, University of Arizona, Tucson, AZ 85721, USA. ljubo@email.arizona.edu
Djordjevic
Ivan B
IB
Xu
Lei
L
Wang
Ting
T
Kueppers
Franko
F
D017076:Computer-Aided Design; D044962:Data Compression / Q000379:methods*; D004867:Equipment Design; D019544:Equipment Failure Analysis; D005336:Fiber Optic Technology / Q000295:instrumentation*; D012815:Signal Processing, Computer-Assisted / Q000295:instrumentation*; D013685:Telecommunications / Q000295:instrumentation*