有限反馈波束成形中继系统性能分析

Performance Analysis of Relay Networks Based on Limited Feedback Beamforming

为研究量化反馈对多天线中继系统性能的影响,推导出中继采用有限反馈波束成形转发信号时系统的中断概率和容量.计算出终端接收信噪比的矩母函数,再利用拉氏逆变换获得系统的中断概率,基于Jensen不等式推导出容量的理论上界,利用数值仿真对理论推导结果进行了验证.仿真结果表明,有限反馈波束成形可以很好地实现性能和反馈量的折中,且随着天线数和反馈量的增加,系统性能会得到提高.

To analyze the impact of quantized feedback on multi-antenna relay system,the letter derives the outage probability and capacity of relay system,which retransmits signal by using limited feedback beamforming. First,we derive the moment generation function of received signal-to-noise ratio and achieve the outage probability by using inverse Laplace transform. Second,we derive the capacity upper bound based on Jensen＇s inequality. Finally,Numerical results are given to verify the correctness of theoretical derivation. Theoretical and simulated results prove that the limited feedback beamforming could achieve the tradeoff between performance and feedbacks. The system performance can be improved by the increase of antenna numbers and feedback bits.