Research on Adaptive Modulation of MIMO MPSK Systems

Adaptive modulation is an effective means to make full use of wireless channel capacity and average spectral efficiency in multiple input multiple output systems. Based on the optimal bit allocation algorithm in MIMO systems, a new algorithm was proposed which calculate the total power constraint for each sub-channel to determine the modulation mode by rounding down means. Then according to the residual power, the modulation order was revised. The proposed scheme makes full use of the residual power and speeds the algorithm convergence. The program flow of the new algorithm not only adapts to adaptive modulation based on maximum average spectrum efficiency, but also suitable for minimum transmit power algorithm. Simulation results show that the proposed algorithm can greatly reduce the complexity of computing.