FIR filter optimization as pre-emphasis of high-speed backplane data transmission

FIR filter pre-emphasis has been used to counteract inter-symbol interference (ISI) in high-speed backplane data transmission. In this paper, backplane channel characteristics are first analyzed. It is found that channel group delay distortion is also a major ISI contributor in addition to amplitude attenuation. A MATLAB program is then described for optimization of FIR filter under LMS criterion. Both symbol-spaced FIR (SSF) and fractionally spaced FIR (FSF) are comparatively studied at different data rates. The determination of tap number and preference of FSF to SSF are discussed