多信道认知用户饱和吞吐量分析

为计算认知网络中系统饱和吞吐量的变化情况,提出一种分析认知用户间饱和吞吐量的三维马尔科夫模型.模型假设存在有限的认知用户在理想的信道上通信,通过分析802.11DCF(distributed coordination function)提供的两种退避接入机制,计算出认知用户间饱和吞吐量的理论值,并通过NS2仿真软件建立多信道实验场景,计算系统实际吞吐量.实验结果表明,多信道理论仿真结果与实际吞吐量基本吻合;随着认知用户信道数的增加,系统的饱和吞吐量近似成线性增加.

Throughput analysis of multi-channel cognitive users

In order to compute the change of system saturation throughput in cognitive network,a three dimensional Markov chain model was presented to analyze the saturation throughput of cognitive users,with the assumption of finite number of cognitive users and ideal channel conditions.The model was applied to two access mechanisms proposed by IEEE 802.11 to compute the theoretical value of saturation throughput between cognitive users.A multi-channel simulation platform was built by NS2 to compute the actual saturation throughput.Compared with simulation results,the model is extremely accurate in predicting the system throughput and the system throughput increases linearly with the number of cognitive users’ channels.