Adaptive Modulation for MIMO System Based on Limited Feedback

The MIMO channel is changed into the mixture channel using the eigenvector of the channel matrix. The adaptive modulation together with power allocation is studied in order to maximize the system capacity under the constraint of total transmit power and Quality of Service (QoS). The information needed at the transmitter such as beamforming vector and power allocation vector is conveyed back using limited feedback. The simulation results show that the proposed scheme can improve the capacity greatly at low SNR.