Order Selection Based on Performance Simulation of FS-DFE

To select the order (tap number) of feedforward filter of a fractionally spaced decision feedback equalizer (FS-DFE), the relationship between the order and the equalization performance was studied. Under the known channel characteristics, in variant signal noise ratio and order of feedforward filter, the optimal tap coefficients of FS-DFE was calculated with given algorithm, then the bit error rate performance was simulated using Monte Carlo method and compared with that of symbol spaced decision feedback equalizer (SS-DFE). Finally a method of how to select the order of FS-DFE feedforward filter based on simulation result was proposed and this method could be taken as a reference of FS-DFE engineering design.