Performance improvement of decode-and-forward relay systems using dual polarized antenna

This paper studies performance of two-hop decode-and-forward (DF) relay system with the implemented polarization receive diversity system at the destination terminal. Communication between the source and the relay is assumed to be over the Ricean fading channel, while two correlated and non-identical Ricean fading channels are assumed for the relay to destination link. Maximal ratio combining (MRC) of the received signals is performed at the destination, and no direct communication between the source and the destination is considered. In order to determine the level of improvement introduced through the implementation of polarization diversity, performances of the considered system are compared with the standard DF relay system with single antenna terminals. The obtained results show that, using polarization diversity, the same BER (Bit Error Rate) values can be obtained with significantly lower SNR (Signal to Noise Ratio), despite a certain level of correlation and power unbalance between the diversity branches. In that manner, compared to the system with no diversity, the total needed transmit power for achieving the same level of system performances is reduced, and thus more energy efficient communication is enabled.