Title :
Performance of smart lightwave receivers with linear equalization
Author :
Cartledge, John C. ; Mckay, Ross G. ; Nowell, Mark C.
Author_Institution :
Dept. of Electr. Eng., Queen´´s Univ., Kingston, Ont., Canada
fDate :
8/1/1992 12:00:00 AM
Abstract :
Signal processing techniques can be used to reduce linear and nonlinear distortion in high-speed lightwave systems caused by fiber dispersion and nonideal responses of optoelectronic and electronic components. The improvement in the performance of 2.5 and 10 Gb/s intensity modulation, direct detection systems is assessed for receivers which utilize an analog taped delay line equalizer to compensate for signal distortion. Synchronous and fractionally spaced equalizers are evaluated. Smart receivers that jointly optimize the decision time, decision threshold, and equalizer tap weights under a minimum bit error ration criterion are considered. This yields the optimum system performance and allows consideration of both reduced distortion and enhanced noise arising from the signal processing. The effectiveness of the equalization is determined as a function of several important system parameters. Three-tap and five-tap synchronous equalizers yield virtually the same improvement in receiver sensitivity. Depending on the system, a five-tap fractionally spaced equalizer with half-bit-period tap spacing may or may not be significantly more effective than a three-tap synchronous equalizer
Keywords :
equalisers; optical communication equipment; optical dispersion; optical fibres; optical modulation; 10 Gbit/s; 2.5 Gbit/s; analog taped delay line equalizer; decision threshold; decision time; direct detection systems; enhanced noise; equalizer tap weights; fiber dispersion; five-tap synchronous equalizers; fractionally spaced equalizers; half-bit-period tap spacing; intensity modulation; lightwave systems; linear distortion; linear equalization; minimum bit error ration criterion; nonideal responses; nonlinear distortion; optimum system performance; receiver sensitivity; signal distortion; signal processing; smart lightwave receivers; system parameters; Bit error rate; Circuit noise; Delay lines; Equalizers; Laser noise; Nonlinear distortion; Optical distortion; Optical filters; Optical noise; Optical receivers;
Journal_Title :
Lightwave Technology, Journal of