03695nas|a2200457 i 4500 20260818134612.0 050799s1998 u uzm rtt 00| a1eng d .b11754308 AIT Thesis no.TC-98-04 Chao, Xin Qin Improvement on the capacity of WDM systems by using error correction codes Bangkok : Asian Institute of Technology, 1998 76 p. Thesis ; no. TC-98-04 A thesis submitted in partial fulfillment of the requirement for the degree of Master of Engineering, School of Advanced Technologies Thesis (M.Eng.) - Asian Institute of Technology, 1998 A system configuration is proposed in which the Intensity Modulation (direct modulation) and PIN Direct Detection (IM/DD) scheme is employed in the Wavelength Division Multiplexing system with or without EDF A as optical preamplifier. This approach only need low cost multi-mode Fabry-Perot laser as light source and eliminate the need for an expensive single-mode optical laser. Based on the use of tunable Fabry-Perot optical filter as demultiplexer to select the desired channel signal from multichannel signals, the tradeoff between power efficiency of optical filter and bandwidth efficiency of WDM system has been studied, the optimized optical bandwidth bas been achieved. In this work, the performance of optically preamplified intensity modulation-direct detection (IM-DD) receiver is investigated in terms of bit error rate and sensitivity by employing semiclassical theory coupled with Gaussian approximation method. The analysis provides closed-form expression for sensitivity. Our results show that the total number of uses in WDM system strongly depends on the type of optical filter and the optical bandwidth chosen. In addition our results show direct modulation method limits the capacity of WDM systems due to frequency chirping which relaxes signal spectrum linewidth. We present the very efficient way to improve the capacity of the WDM systems by using forward error correction (FEC) codes. After using FEC the total number of channels which the WDM system can support has been doubled. Optical communications Error-correcting codes (Information theory) Zhang, Jian-Guo, Chairperson Sharma, A.B., Examination Committee Erke, Tapio J., Examination Committee Asian Institute of Technology Partial Scholarship, Scholarship donor Asian Institute of Technology. Thesis ; no. TC-98-04 Full-Text http://203.159.5.9/ait-thesis/detail.php?q=B13569 .b11754308 mnait y 240717 0 990705 m a y 0 mnait mnait mnarc mnarc 22 40 20 Barcode : 30050120808497 CREATED : 2014-05-15 RECORD # : i12800053 LPATRON : 0 LCHKIN : - # RENEWALS : 0 # OVERDUE : 0 IUSE3 : 0 TOT CHKOUT : 0 TOT RENEW : 0 Barcode : 30050160045679 CREATED : 2016-02-03 RECORD # : i12888011 LPATRON : 0 LCHKIN : - # RENEWALS : 0 # OVERDUE : 0 IUSE3 : 0 TOT CHKOUT : 0 TOT RENEW : 0 Barcode : 30050211018063 CREATED : 2022-03-24 RECORD # : i13374941 LPATRON : 0 LCHKIN : - # RENEWALS : 0 # OVERDUE : 0 IUSE3 : 0 TOT CHKOUT : 0 TOT RENEW : 0 Barcode : 30050211018055 CREATED : 2022-03-24 RECORD # : i13374953 LPATRON : 0 LCHKIN : - # RENEWALS : 0 # OVERDUE : 0 IUSE3 : 0 TOT CHKOUT : 0 TOT RENEW : 0 58784 58784 0 0 0 0 MAIN MAIN mnarc 2026-08-18 50.00 0 AIT Thesis no.TC-98-04 30050120808497 2026-08-18 13:46:12 3 2026-08-18 22 0 0 0 0 MAIN MAIN mnarc 2026-08-18 0 AIT Thesis no.TC-98-04 30050160045679 2026-08-18 13:46:12 2026-08-18 40 0 0 0 0 MAIN MAIN mnait 2026-08-18 50.00 0 AIT Thesis no.TC-98-04 30050211018063 2026-08-18 13:46:12 1 2026-08-18 20 0 0 0 0 MAIN MAIN mnait 2026-08-18 50.00 0 AIT Thesis no.TC-98-04 30050211018055 2026-08-18 13:46:12 2 2026-08-18 20