On the design of sinc interpolator for pilot symbol assisted modulation systems

This paper investigates the design of practical sine interpolation filters in pilot symbol assisted modulation (PSAM) systems. By closely examining the error mechanism in PSAM channel estimation, we show that the error floor phenomenon is caused by the non-ideal characteristic of the interpolation filter. Based on the use of adjustable window functions, 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.