【摘要】 在平坦相关瑞利和莱斯衰落信道下,基于泰勒级数展开、高斯分布和Gamma分布,对正交空时分组码系统的遍历容量和容量累积分布函数进行近似分析.对于遍历容量,在低信噪比和天线数目较多情况下,采用一阶近似效果很好,但是在高信噪比和天线数目较少时,一阶近似效果不是很理想,然而采用二阶近似,在任意的信噪比和任意的天线数目下,都具有很好的近似效果.对于系统的容量分布函数,采用高斯和Gamma近似方法,都得到很好的近似效果;在高中断区域,采用高斯近似效果较好;但是在低中断概率区域,Gamma近似具有更好的近似效果.更多还原

【Abstract】 Based on the Taylor series expanding,Gaussian distribution and Gamma distribution,this paper studied the accuracy of Guassian and Gamma approximations to the ergodic capacity and capacity cumulative distribution(CDF) of orthogonal space-time block codes(OSTBC) over flat correlated Rayleigh and Ricean fading channels.It was shown by simulation that the first ordered approximation to the ergodic capacity was valid only for lower SNR region and large number of antennas,and the second ordered approximation was very accurate for any value of SNR and any number of antennas.The Gaussian and Gamma approximations to system capacity cumulative distribution function were very accurate.In particular,the Gaussian approximation is better when outage probability is large,and the Gamma approximation is more effective when outage probability is small.更多还原