Performance of Decode and Forward MIMO Relaying using STBC for Wireless Uplink

This paper compares the performance of a decode and forward relay assisted wireless uplink with direct wireless uplink in the presence of rayleigh fading where source is equipped with single transmit antenna (Tx), relay is equipped with multiple transmit and receive antennas (Rx), and destination has multiple receive antennas. Data are modulated using QPSK or 16 QAM or 64 QAM modulator at source and send to relay which combine and decode the incoming signal using Maximum Likelihood decoding and further encode the symbols using STBC, and the encoded data are split into n streams which are simultaneously transmitted using n transmit antennas of relay. It is observed that relay with 2Tx or 3Tx or 4Tx and 2Rx or 3Rx or 4Rx provides 1 dB to 22 dB gains at 10 compare to direct link where destination has 2Rx or 3Rx or 4Rx. And there is around 1 dB to 7 dB gains for increasing number of Tx antennas from 2 to 3 or 3 to 4 at relay.