Original research articleChannel estimation algorithms comparison in long-reach passive optical network based on block-IFDMA

A novel flexible and cost-effective long-reach transmission scheme employing Block-interleaved frequency division multiple access (B-IFDMA) is proposed for next-generation PONs. An erbium doped fiber amplifier (EDFA) is adopted to amplify the optical signal at the optical line terminal (OLT) and optimized channel estimation algorithms are employed at the receiver. 25 Gb/s double-sided band (DSB) B-IFDMA PON is demonstrated over 100 km fiber by simulation. Four kinds of channel estimation algorithms are used to improve transmission performance. Simulation results show that the Linear Minimum Mean Squared Error (LMMSE) estimator has better performance than the others. Compared with original Least Square (LS) channel estimation, the receiver sensitivity is improved 1 dBm at bit error rate of 10−3.