Comparison of BER Performance of Cooperative Wireless Systems Based on D-OSTBC, D-EOSTBC and DF Relaying Protocol

Abstract

The end-to-end bit error rate (BER) performance analysis of cooperative wireless communication networks based on distributed orthogonal space time block coding (D-OSTBC) (Alamouti) scheme, distributed extended orthogonal space time block coding (D-EO-STBC) and decode-and-forward (DF) relaying protocol, are addressed. There are two main relaying techniques which are amplify-and-forward (AF) and decode-and-forward (DF). Opposed to that in conventional multi-input multi-output (MIMO) systems, cooperative systems, the antennas are distributed among different terminals, which easy to establish cooperative MIMO. This paper will deal with three system models of wireless communications. The first model is conventional single-input single-output (SISO) system, which consists of one source and one destination. The second model is cooperative MIMO based on two relays and D-OSTBC (Alamouti) scheme. This system consists of one source, two relays and one destination. The third model is cooperative open loop MIMO based on four relays and D-EO-STBC technique. This system consists of one source, four relays and one destination. All these schemes are based on DF protocol and analyzed over flat fading channels. Also, QPSK digital modulation scheme is used for all schemes. MATLAB simulations confirm that the BER performance of cooperative SISO is the worst, whereas, the best BER performance is achieved by the system with four relays and based on D-EO-STBC techniques.