Performance tradeoffs between diversity schemes in wireless systems

Multiple antennas at the transmitter side and/or at the receiver side can improve the capacity and/or quality of reception in a fading environment. In this paper, a comparative study of various diversity schemes with and without feedback is presented. Simulation results show that maximal ratio combining (MRC) and transmit beamforming provide maximum performance. The other focus of this paper is to modify the weight vector for equal gain transmission (EGT) using quantized feedback of the channel state information (CSI) so that a close optimal performance can be obtained with less feedback. Simulation results show that three bits is sufficient to achieve this performance.