An Evaluation of Channel Estimation Methods for MIMO-OFDM System

Orthogonal Frequency Division Multiplexing iscombining use of Multiple Inputs Multiple Outputs methodas known as OFDM-MIMO system. This helps to increasethe capacity of system to obtain better efficiency of spectrum. This article presents a comparative analysis of various channel estimation techniques used in multicarriersystems. Accurate channel assessment is the biggestobstacle to overcome when processing the incoming signal. A Time Domain Interpolation (TDI)-based strategy has beenintroduced by using zero padding and the Inverse DiscreteFourier Transform (IDFT) to transform the estimatedchannel into the time domain and then the TDI is achieved. By using this channel estimation algorithm issues like ICI and it is mostly caused by carrier offset effect are significantly minimized. An evaluation of LS, LS-Spline, MMSE for QAM and QPSK schemes has been done forvaried SNR and FFT values. The channel estimation provides better results when the DFT is applied to thepredicted channel power for the 16-QPSK modulation scheme.