DFT based Channel Estimation Methods for MIMO-OFDM System using QPSK modulation technique

Multiple-Output (MIMO) antenna systems provide high transmission data rate, spectral efficiency and reliability for wireless communication systems. These parameters can be further improved by combating fading, the effect of which can be reduced by properly estimating the channel at the receiver side. In this paper a new approach based on time-domain interpolation (TDI) has been presented. TDI is obtained by passing estimated channel to time domain through Inverse Discrete Fourier Transform (IDFT), zero padding and going back to frequency domain through Discrete Fourier Transform (DFT). The analysis of the channel estimators has been conducted using a MATLAB. The comparison has been carried out between power of true channel and estimated power for the given channel using LS, LSSpline and MMSE for QPSK modulation at SNR 30dB. It is investigated that by applying the DFT over the estimated power of channel, the performance of the channel estimators becomes better.