Performance Analysis of Adaptive MIMO OFDM System over Adaptive SISO OFDM System

Abstract

The need of any communication system is high data speed with higher accuracy and reliability. Orthogonal Frequency Division Multiplexing (OFDM) provides optimistic solution for achieving high data rates in wireless environment. Orthogonal frequency division multiplexing (OFDM) is one of the multicarrier modulations, in which all of the sub channels are dedicated to a single data source In an OFDM transmission system, each subcarrier is attenuated individually under the frequency-selective and fast fading channel. If the same fixed transmission scheme is used for all OFDM subcarriers, it results in high attenuation and hence poor performance. Multiple input multiple output (MIMO) communication systems when integrated with the OFDM system can obtain high data rate transmission over broadband wireless channels. The purpose of this paper is to compare adaptive single input single output (ASISO) -OFDM with adaptive multiple input multiple output(AMIMO) -OFDM system and why MIMO is better than SISO is stated. Based on calculated average instantaneous signal to noise (SNR) same modulation scheme is applied to all subcarriers of same block. Average bit error rate (BER) performance of MIMO-OFDM system under fixed modulation and adaptive modulation is observed. The simulation results show that BER performance of MIMO-OFDM system using adaptive modulation is better than fixed modulation.
DOI: 10.17762/ijritcc2321-8169.1505189