Research On The Low Complexity Power Allocation Algorithm In MIMO System

With the rapid demand in wireless communication services, how to efficiently utilizes the limited frequency resource becomes a challenge .The multiple-input multiple-output (MIMO) belongs to space processing technology, and it can improve both the frequency reuse efficiency and system bit-error-rate (BER)performance, referred to as space multiplying and space diversity, respectively MIMO technology utilizes multiple transmit and receive antennas to transmit and receive data respectively, and it breaks the conventional single-input single-output(SISO)wireless communication model. Through power allocation for transmit antennas; the system performance can be improved in further.The forgoing research has shown that the water-filling algorithm is the optimal power allocation scheme .when the channel state information (CSI) is perfectly known at the transmitter side. However, the algorithm needs the complete channel state information, resulting in higher computational complexity, and reduces the utilization of the channel; it is hard to achieve in the project. To reduce the complexity for power allocation scheme in MIMO system, this thesis proposed a new scheme base on Queue Resolve (QR) decomposition, and it can efficiently be combined with procoding technique to control the power allocation. Compared with the conventional power allocation schemes, the proposed scheme only requires partial CSI, and reduces the feedback load and increase the channel reuse efficiency. Simulation results show that the proposed scheme can achieve nearly the same BER performance as the water-filling algorithm, and reduce the computational complexity meanwhile.