【摘要】 协作分集技术利用网络中的多个用户共享天线,形成虚拟多天线系统,可以有效地提高系统性能。电平交叉率和平均中断时间是衡量系统二阶统计特性的重要指标。研究了2个备选中继的增量放大(2R-IAF)协作分集无线传感器网络系统,并且给出了这种系统的中断性能闭合表达式,公式仿真结果表明:中断概率并不是随着切换门限的升高而降低的,在切换门限大于中断门限的时候,随着切换门限的升高,系统中断性能下降。而且研究了系统的二阶统计特性,即平均电平交叉率和平均中断时间,结果表明:归一化电平交叉率和归一化平均中断时间也依赖于切换门限和中断门限的选择。更多还原

【Abstract】 Cooperative diversity technology has been recently proposed as a way to form virtual multi-antenna arrays that can be used to improve the performance of the wireless networks.The average level crossing rate and the average output duration are important index to judge system’s the second-order statisic character.An incremental amplify-and-forward relaying system with two relays(2R-IAF)is presented.Closed-form expressions for the outage probability are given.And the average level crossing rate and the average output duration of the 2R-IAF system are also presented.Results show that the normalization average level crossing rate and the average output duration are highly dependent on the choice of switching threshold and outage threshold.更多还原