Abstract

Background and Objective: This paper considers the model in which the digital feedback equalizer (DFE) together with oblique projection (OB) has been used to minimize the effect of Inter symbol Interference and Inter carrier Interference in multiple input multiple output orthogonal frequency division multiplexing system. The conventional MIMO-OFDM system uses cyclic prefix (CP) to remove ISI in received signals & this cyclic prefix is just an overhead on the transmitted data. In the proposed model CP has been removed and placed with Oblique Projection for saving the bandwidth. Usually by eliminating the CP in the system, the effect of ISI and ICI is not sufficiently removed. The frequency- domain block based decision feedback equalizer with oblique projection technique is proposing to dealing with this problem. This will also improve the spectral efficiency of the system. The proposed system has been able to give improvement of 12dB SNR at BER of 26dB in MMSE equalization and 27dB in zero forcing (ZF) decoding as compared to CP based conventional MIMO-OFDM system.

Result and Conclusion: Further the proposed system has been able to increase the achievable rate at 0dB SNR the rate is 1.8 bits/sec/Hz.

Keywords: MIMO, CP-OFDM, Decision Feedback Equalizer, Oblique Projection, STBC, ICI, ISI.

Graphical Abstract