Mazher, Wamidh JalilBayat, OğuzUçan, Osman Nuri2021-05-152021-05-1520171738-7906https://hdl.handle.net/20.500.12939/912mazher, wamidh jalil/0000-0003-2092-3745In this paper, we reconfigured the SD-4 code with both: long and very long code lengths. Firstly, we generated SD-4 code with 15 codeword length that implies SD-4 code 3,900 lengths, secondly, we extended SD-4 code to 32,768 which is very long code length. Our model is based on SD-4 code as an encoding/decoding block cascaded by multiple pulse-position modulations (Q-PPM) in FSO communication environment. Such model performance is evaluated by lognormal atmospheric turbulent fading channels. Furthermore, coding gains are compared with different code lengths and Q-PPM modulations to demonstrate such codes ability of coding with pulse position modulation (Q-PPM). The optimal obtained raw code gain is equal to 0.56 dB for SD-4 at code length (4096) which analyzed with BPPM regarding the other related codewords (channel throughput is not considered). Meanwhile; the real code gain results have been obtained and equal to 3.87 dB at code length (32768) for such channel(channel throughput is considered). Tto demonstrate the SD-4 code ability to be coded with Q-PPM, we analyzed such code utilizing 4PPM and 8PPM. Also, we compared our results with existing results for other techniques namely : Hamming, Reed-Solomon, and Bose-Chaudhuri-Hocquenghem.eninfo:eu-repo/semantics/closedAccessLDPCHamming DistanceSystematic CodingFSOPPM. Channel ThroughputArticle1712512WOS:000423934000002N/A