Effect of mutual coupling between UE transmitted elements on WCDMA STOB MIMO system performance

In this paper, complex base band wide band code division multiple access (WCDMA) signal and system models containing their electromagnetic (EM) features in free space are developed. Based on the models and the EM characteristics of user equipment (UE) antennas, the effect of mutual coupling (MC) between the antennas on a WCDMA 2×4 multiple input multiple output (MIMO) system uplink performance, when using Space Time Orthogonal Block Codes (STOB) transmitting and minimum mean square error (MMSE) beam forming receiving techniques, is investigated. Two results are obtained: 1) the MC effect has ability to influence the channel estimation when transmitted antennas are identified; 2) the MC effect has the positive contributions on system SINR gain about 1.2 dB compared with that when the MC effect is not considered.