8 Channel Estimation Enhancement in OFDM System based on Time Domain Interpolation

In practical OFDM systems the transmitter send the data out through a multipath fading channel. At the receiver, the received data distorted by the channel characteristic. So, in order to recover the transmitted data, the channel effect must be estimated. In this paper channel estimation based on comb type pilot arrangement has been investigated by implementing least Square (LS) and Minimum Mean Error Square (MMSE) channel estimator to estimate the channel at the pilot locations. While the channel interpolation was done using linear interpolation, and time domain interpolation techniques. Also DFT-based estimation technique proposed to improve the performance of LS and MMSE estimator even more. Both LS and MMSE estimator have been implemented with and without DFT-based estimation technique and compare their performance by measuring the bit error rate BER with BPSK as modulation scheme and the channel is assumed to be multi-path Rayleigh slow fading channel based on Clark's model