独立不同分布Nakagami-m信道下选择合并分集信噪比的统计特性及其应用

On the statistics of the outcome SNR of selective combiner over i.n.d. Nakagami-m channels and its applications

本文推导了独立不同分布Nakagami-m(m为整数)衰落信道模型下接收端采用选择合并方式时信噪比的概率密度函数(probability density function,PDF)的闭式表达式.该表达式由有限多个幂函数与指数函数乘积的求和形式组成,可作为一个非常有用的数学工具来分析在独立不同分布Nakagami-m衰落信道下采用选择合并分集技术时的无线通信系统的中断概率、误符号率和遍历容量等性能,还可以用于研究物理层保密性能,比如保密中断概率(secrecy outage probability,SOP)和平均保密容量(average secrecy capacity,ASC).在单输入多输出(single-input multiple-output,SIMO)的无线通信系统中,本文以无线信息与能量同步传输(simultaneous wireless information and power transfer,SWIPT)通信系统为例,利用所得信噪比的PDF表达式研究了该系统的保密性能,进一步得到SOP和ASC的闭式表达式,最后通过数值仿真和Monte Carlo仿真对推导得到的SOP和ASC闭式表达式的准确性和有效性进行了验证.

The closed-form analytical expression of the probability density function（PDF） of the outcome signalto-noise ratio at the selective combiner（SC） over independent but not necessarily identically distributed（i.n.d.）Nakagami-m fading channels is derived.The proposed expression is in the form of multiple finite summations of the product of the power and exponential functions.The obtained expression can be considered as a useful mathematical tool to analyze the performance of the wireless communication systems adopting SC over i.n.d.,Nakagami-m fading channels,such as outage probability,bit/symbol error rate,and ergodic capacity as well as secrecy performance,including secrecy outage probability（SOP） and average secrecy capacity（ASC）.As an example,closed-form analytical expressions are derived for the SOP and ASC of a single-input multiple-output simultaneous wireless information and power transfer system.The accuracy and validity of the derived expression are justified through extensive comparisons between numerical and simulation results.