MIMO-OFDM with Enhanced Channel Estimation based on DFT Interpolation

Abstract

In practical wireless communication systems, the transmitter send the information out through a multipath fading channel. At the receiver side, the received information distorted by the channel characteristic (due to multipath fading). So, in order to recover the transmitted information accurately, the channel effect must be known at the receiver. In this paper channel estimation for STBC-MIMO-OFDM system has been investigated by implementing the most popular channel estimators least Square (LS) and Minimum Mean Error Square (MMSE) both based on comb type pilot arrangement to estimate the channel effect at pilot locations, and channel interpolation between pilot locations was done using linear interpolation. The performance of LS and MMSE estimators can be improved by using DFT-based estimation technique. LS and MMSE estimator have been implemented with and without DFT-based estimation technique to estimate the channel effect for STBC-MIMO-OFDM system and compare their performance by measuring the bit error rate BER with QAM as modulation scheme and for different MIMO antenna configurations, also the channel between each antenna pair is assumed to be multipath Rayleigh Slow fading channel based on Clark's model. General Terms Channel estimation, communication, DFT algorithms.