The analysis of Scattered Pilot OFDM System and the discussion of channel estimation based on Two Dimensional Interpolation Filter

ABSTRACT In a scattered pilot orthogonal frequency division multiplexing system (OFDM), it is similar to sampling the two-dimensional (2D) channel frequency response (CFR) that a receiver obtains the CFR at pilot subcarriers from several OFDM symbols. In this study, the sampled 2D CFR was considered a sampled image. Then, the 2D spectrum of sampled image was analyzed. On the basis of the analysis results, the performance of a 2D linear interpolation filter used for estimating the CFR is discussed here; moreover, constraints on the use of the filter are outlined. Furthermore, an approach for designing a 2D interpolation filter under conditions where 2D linear interpolation filters are not suitable is detailed. Keywords: Orthogonal frequency division multiplexing, channel estimation, interpolation filter