A practical method of designing DFT-based channel estimator

The orthogonal frequency division multiplexing (OFDM) system requires precise channel estimation for better system performance. Among various channel estimation methods, the discrete Fourier transform (DFT)-based channel estimation is favored because it has simple architecture and shows as good performance as the linear minimum mean square error (LMMSE) estimation method. However, the DFT itself has its own complexity which should be overcome to achieve high speed operation as well as simple implementation. This paper suggests a practical method of DFT-based channel estimator which uses power-of 2 fast Fourier transform (FFT) instead of complicated non-power-of 2 DFT. The validity of our proposed channel estimator is proved through simulation and error vector magnitude comparison.