Research on the power allocation algorithm in MIMO-OFDM systems

MIMO (Multiple-Input-Multiple-Output) and OFDM (Orthogonal Frequency Division Multiplexing) are the key techniques for the new-generation wireless communication systems. With the typical resource allocation optimization model, the capacity performance of the power average allocation and water-filling allocation algorithm for MIMO-OFDM systems were simulated and compared in this paper. The simulation results show that when the SNR (Signal-to-Noise Ratio) is low, the water-filling allocation algorithm earns more system capacity than the power average allocation, and when the SNR is high, the capacity performance of these two algorithms are almost the same, while the power average allocation lowers the system complexity greatly. Furthermore, in view of high computational complexity of the classical water-filling algorithm, we propose an improved water-filling algorithm with low complexity whose performance comes close to the classical water-filling algorithm.