Performance improvement of two-hop cooperative relay system under correlated Ricean fadings

This paper studies performance of two-hop cooperative relaying system employing regenerative decode-and-forward (DF) technique. Infrastructure based relay equipped with dual-polarized antenna is assumed, performing maximal ratio combining of the received signals. Link between the source and the relay is characterized as two correlated and non-identical Ricean fading channels. There is also direct communication between the source and the destination. In order to determine the level of improvement introduced through the implementation of polarization diversity, performances of the considered system are compared with the DF relay system with single antenna relay. 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.