基于MIMO信道估计误差模型的功率分配与自适应调制算法

A Novel Algorithm of Power Allocation and Adaptive Modulation for MIMO Systems Based on Channel Estimation Error Model

该文分析了瑞利平坦衰落信道下,信道估计误差对采用迫零接收的MIMO系统性能的影响,提出了一种以系统有效吞吐量最大化为目标的功率分配与自适应调制算法。为了减少信道估计误差对实际系统性能的影响,该算法对发送端估计的信噪比进行修正,并以此作为功率分配和自适应调制的依据。在系统总功率受限的条件下,对发端多天线的功率分配结合了空域注水定理和比特分配,并尽量保证调制阶数高的数据符号所在天线的功率。仿真结果表明,该算法实现较简单,获得的系统有效吞吐量接近于最优值,适用于实际系统。

The effect of channel estimation error on the performance of Multiple-Input Multiple-Output （MIMO） Zero-Forcing （ZF） receivers in uncorrelated Rayleigh flat fading channels is investigated, and a novel algorithm of power allocation and adaptive modulation is proposed in this paper to maximize the system effective throughput. To reduce the channel estimation error＇s effect on actual system throughput, the SNR derived at the transmitter is modified, which is used in power allocation and adaptive modulation. With the sum of transmit power limited, the power allocation of transmit antennas uses spatial water-filling theorem and bit allocation, and ensures the power of the antenna with high modulation data symbols. The numerical results show that the system effective throughput of the proposed algorithm is near optimal with acceptable implementation complexity, which is suitable for the actual system.