基于Double-Nakagami-m的非对称全双工AF中继车载通信系统

Performance analysis for asymmetric full-duplex vehicle to vehicle communication system in Double-Nakagami-m fading channel

针对车载通信系统通信中断问题,提出基于Double-Nakagami-m的非对称全双工AF(amplify-and-forward)中继车载通信系统。全双工技术允许通信车辆节点在一个时隙内完成信息交换,AF物理层网络编码技术可降低系统解码复杂度。假设信道服从Double-Nakagami分布,为了解决车辆行驶中由于相对速度过大对系统性能产生的影响的问题,采用全双工AF中继转发车辆通信的信息,以保证该系统容量满足行驶车辆通信要求,并提高通信频谱资源使用效率。为了仿真非对称速率车载通信环境,假设不同速度的车辆进行通信,并用中断概率衡量该通信系统是否可靠。数值分析结果表明,速率非对称程度越低,系统可靠性能越好,当速率非对称程度从1/9变化至1时,系统最低中断概率减小了约5.3×10^-2,且信道衰落系数对系统性能影响比信道功率因子的影响程度要高,改变信道衰落系数可以使得系统中断概率减小至4.83×10^-5,从而提高了系统可靠性。

A two-way full-duplex amplify-and-forward(AF)cooperative communication scheme is proposed to reduce the time-delay of vehicular communication systems.Note that the full-duplex technology allows vehicles exchanging information in one time slot and AF can be used to reduce the system decoding complexity.Assuming that the channel obeys the Double-Nakagami fading channel,in order to solve the problem that the relative speed is too large to affect the system performance during vehicle travel,this paper uses full-duplex AF relay to forward the information of vehicle communication to ensure that the system capacity meets the vehicle communication requirements and improve the efficiency of the use of communication spectrum resources.For different asymmetric transmission rate,this paper assumes that vehicles of different speeds communicate and use the probability of interruption to measure whether the communication system is reliable.The results of numerical simulation show that the lower the rate asymmetry,the better the system reliability,when the rate asymmetry changes from 1/9 to 1,the system′s minimum outage probability is reduced by about 5.3×10^-2.Moreover,the channel fading coefficient has a higher influence on the system performance than the channel power factor,changing the channel fading coefficient can reduce the system interruption to 4.83×10^-5,thus effectively improving the system reliability.