Minimization Of Inter Carrier Interference Using Iterative Technique for Mimo-Ofdm

Abstract

In orthogonal frequency division multiplexing – multiple input multiple output  (OFDM-MIMO) systems, in multipath fading channels the time period of an OFDM block is not constant. As a result, the sub-carriers lose their orthogonality and create intercarrier interference (ICI). Lot of research has been carried out to cancel or mitigate the effects of ICI in OFDM-MIMO systems but these methods are computationally complex.  Here we use a low-complexity based frequency-domain algorithm to cancel the ICI created in time-varying multipath channels. Simulation with BPSK and QPSK demonstrates the performance of our algorithm in comparison to channels with ICI and no ICI. The results are also compared with zero forcing equalization algorithm which is the algorithm used presently in the OFDM-MIMO systems. Based on Fast Fourier Transform, iterative linear MSE has been implemented to maximize the output signal to noise/interference ratio in the MMSE estimates during iterative detection. It shows that 15 db signal to noise gain is achieved when bit error rate is .