Effective interpolator design for pilot symbol assisted modulation systems

This paper investigates the design of practical sinc interpolation filters in pilot symbol assisted modulation (PSAM) systems. By closely examining the error mechanism in PSAM channel estimations, it is shown that the error floor phenomenon is caused by the non-ideal characteristic of the interpolation filter. We present a set of design guidelines to determine the shape of window functions, the window/filter length and the pilot insertion rate. The design choices essentially reflect the trade-offs between error performance, implementation complexity and transmission rate.