An iterative DFT-based channel estimation algorithm for OFDM systems with virtual carriers

This paper presents a comb type pilot symbol aided iterative DFT-based channel estimation technique for orthogonal frequency division multiplexing (OFDM) systems with virtual subcarriers (VCs). The algorithm is initialized such that the channel frequency response (CFR) has continuous transition between the active and virtual band. The technique reduces the estimation error at the edge subcarriers iteratively by generating improved CFRs corresponding to the missing pilots in the null spectrum. As a result of this, the complete CFR is estimated more accurately. Presented simulation results demonstrate that the proposed algorithm achieves fast convergence and better estimation performance than its low complexity iterative DFT-based counterpart.