Performance Evaluation of a Cooperative OFDM system with implementation of Decode and Forward and Amplify and Forward Relaying Protocols on Text message transmission
Mafruha Mowrin Hossain, Shaikh Enayet Ullah · 2011
Cooperative diversity is a newly proposed virtual MIMO technology based transmission technique achieving diversity gain through a combination of the relayed signal and the directly transmitted signal. In this paper, we made a comprehensive study to elucidate the performance of a single-relay cooperative OFDM system under Amplify-and-Forward (AAF) and Decode-and-Forward (DAF) relaying strategies on Text message transmission. The bit-interleaved channel encoded system under investigation incorporates four conventional signal combining schemes such as Equal Ratio Combining (ERC) and Fixed Ratio Combining (FRC), Signal to Noise Ratio Combining (SNRC) and Enhanced Signal to Noise Ratio Combining (ESNRC) under BPSK and QPSK digital modulations. In the present study, results of BER simulation in AWGN and Raleigh fading channels shows that the AAF relaying protocol supported cooperative OFDM system outperforms in ERC signal combining scheme as compared to others (FRC, SNRC and ESNRC) under BPSK digital modulation . It has been anticipated from the simulation study that the cooperative OFDM communication system provides diversity gain like MIMO system as compared to single antenna transmission system.