Pilot spacing in orthogonal frequency division multiplexing systems on practical channels

Performances of two different channel interpolation methods to be used with Orthogonal Frequency Division Multiplexing (FDM) systems are investigated. The considered scheme uses constant pilot frequencies for channel response estimation. The interpolation techniques are piecewise-constant and piecewise-linear methods which due to their inherent simplicity are straightforward to implement. The results are given as error probability vs. pilot separation for a channel with exponential type power-delay profile and M-ary quadrature amplitude submodulation with M=4, 16 and 64.