存在信道相关时V-BLAST OFDM系统的功率分配算法

Power Allocation Algorithm for V-BLAST OFDM Systems with Channel Correlation

针对存在信道相关及信道估计误差的V-BLAST OFDM系统,提出一种以误比特率为优化目标的自适应功率分配算法。采用基于波束成形的去相关方法降低系统相关性以提升系统性能。发送端在总功率约束条件下,以瞬时误比特率(BER)为优化目标,采用拉格朗日极值法得到自适应功率分配矩阵。仿真结果表明,该算法结合去相关方法可提升V-BLAST OFDM系统的BER性能,且随着信噪比的增大,性能提升明显。

For Vertical-Bell Labs layered Space-time Orthogonal Frequency Division Multiplexing （V-BLAST） system with channel correlation and channel estimation error, this paper proposes an adaptive Transmit Power Allocation （TPA） algorithm to minimize Bit Error Rate（BER）. A decorrelation method based on beam-forming technique is employed in the presence of deteriorative correlation. At the transmitter, the power allocation matrix is calculated by using the Lagrange multiplier method with the total TPA constraint condition. Simulation results show that the proposed TPA algorithm combined with the decorrelation method can improve the BER performance effectively for the actual communication system. With the increase of the signal to noise ratio, the improvement of the performance is more obvious.