Post-FEC BER Assessment with Optimized Decoding Latency for 400 Gbps Transmission Over a 1.8km FSO Field Trial

We experimentally assess the post-FEC BER performance of 400 Gbps FSO transmission over a 1.8 km field-trial, minimizing the LDPC decoding latency to achieve error-free communication with/without optical pre-amplification. Pre-amplification is shown to provide reliability gains exceeding 70%, typically necessitating 3× fewer decoding iterations.