Performance comparison of vector-RAKE receivers using different combining schemes and antenna array topologies

Three potential structures of vector-RAKE (V-RAKE) receivers are compared. An approach where maximal ratio combining (MRC) or conventional beamforming (BF) is applied at each RAKE finger, and a simpler solution where one common BF is used for all fingers. The comparison is conducted by using either single or dual polarized antenna arrays. All results are based on theoretical investigations and analysis of measurement data collected in typical urban environments. It is concluded that the best solution is to use dual polarized antenna arrays, while there is only found to be a minor difference between the considered combining schemes provided the azimuth spread is smaller than the antenna beamwidth